Search

Studies of symptoms after concussion have been focused heavily on athletic and military populations; generalizability to "civilians" has not recently been demonstrated. We selected cognitive symptoms as an important target to assess because of impact on school and employment. We evaluated cognitive complaints in a highly symptomatic (Rivermead Post-Concussion Symptoms Questionnaire [PCSQ], mean [M] = 29.5) civilian sample (

Objective To determine whether people with moderate-to-severe traumatic brain injury (TBI) can adhere to a minimally supervised, community-based, vigorous aerobic exercise program. Design Prospective trial. Setting Young Men's Christian Association (YMCA) facilities. Participants Community-dwelling volunteers (N=10; 8 men, 2 women; age range, 22–49y) 6 to 15 months after moderate-to-severe TBI. Intervention Participants received memberships to local YMCAs and brief orientations to exercise. They were then asked to independently complete ≥12 weeks of ≥3 training sessions per week, performed at 65% to 85% of maximum heart rate for ≥30 minutes per session. Participants could self-select exercise modality, provided they met intensity and duration targets. Programmable heart rate monitors captured session intensity and duration. Main Outcome Measures Independence with equipment and facility use and compliance with training goals (session frequency, duration, intensity, total weeks of training). Results All participants achieved independence with equipment and facility use. All met at least 2 of 4 training goals; half met all 4 goals. Participants averaged (±SD) 3.3±0.7 sessions per week for 13 weeks (range, 6–24). Average ± SD session duration was 62±23 minutes, of which 51±22 minutes occurred at or above individuals' heart rate training targets. Conclusions People in recovery from moderate-to-severe TBI can, with minimal guidance, perform vigorous, community-based exercise. This suggests that decentralized exercise may be logistically and economically sustainable after TBI, expanding its potential therapeutic utility and rendering longer-duration exercise studies more feasible.

Objective: Among survivors of out-of-hospital cardiac arrest (OHCA), the functional outcomes of those with rapid early or with very delayed recoveries are known. For patients between those extremes early recovery is variable, and the probability of longer-term recovery and the implications for quality of life have not been clearly defined. Methods: Twenty-five patients of a consecutive cohort of OHCA survivors with coma duration between 12 h and 7 days and a matched group with acute coronary syndrome underwent cognitive and disability assessments 3 and 12 months after OHCA. Correlations and regression analyses of demographic, clinical arrest variables, and cognitive tests with quality of life outcomes were performed. Results: The OHCA group had impairments in all cognitive domains. There was little cognitive improvement. The OHCA group reported significantly greater health impact and lower quality of life at twelve months than the controls. Longer duration of coma (4–7 versus ≤ 3 days) and greater cognitive impairment at three months, particularly memory impairment, were both associated with reduced late quality of life. Conclusions: These survivors of OHCA had persistent longterm cognitive deficits. Quality of life at one year after OHCA was reduced compared to cardiac controls. Coma duration and memory impairment at three months were harbingers of long term reduced quality of life.

Recognition memory can be subdivided into two processes: recollection (a contextually rich memory) and familiarity (a sense that an item is old). The brain network supporting recognition encompasses frontal, parietal and medial temporal regions. Which specific regions within the frontal lobe are critical for recollection vs. familiarity, however, are unknown; past studies of focal lesion patients have yielded conflicting results. We examined patients with focal lesions confined to medial polar (MP), right dorsal frontal (RDF), right frontotemporal (RFT), left dorsal frontal (LDF), temporal, and parietal regions and matched controls. A series of words and their humorous definitions were presented either auditorily or visually to all participants. Recall, recognition, and source memory were tested at 30 min and 24 h delay, along with “remember/know” judgments for recognized items. The MP, RDF, temporal and parietal groups were impaired on subjectively reported recollection; their intact recognition performance was supported by familiarity. None of the groups were impaired on cued recall, recognition familiarity or source memory. These findings suggest that the MP and RDF regions, along with parietal and temporal regions, are necessary for subjectively-reported recollection, while the LDF and right frontal ventral regions, as those affected in the RTF group, are not.

Regions within the frontal and parietal cortex have been implicated as important neural correlates for cognitive control during conflict resolution. Despite the extensive reciprocal connectivity between the cerebellum and these putatively critical cortical areas, a role for the cerebellum in conflict resolution has never been identified. We used a task-switching paradigm that separates processes related to task-set switching and the management of response conflict independent of motor processing. Eleven patients with chronic, focal lesions to the cerebellum and 11 healthy controls were compared. Patients were slower and less accurate in conditions involving conflict resolution. In the absence of response conflict, however, tasks-witching abilities were not impaired in our patients. The cerebellum may play an important role in coordinating with other areas of cortex to modulate active response states. These results are the first demonstration of impaired conflict resolution following cerebellar lesions in the presence of an intact prefrontal cortex.

Executive dysfunction accounts for significant disability in patients with many types of brain injury in many locations. Clinical reports have described impaired executive functioning after damage to the cerebellum, and anatomical and neuroimaging studies have identified the likely basis for this effect: a cortico—ponto—cerebellar network through which the cerebellum is densely connected to areas of frontal cortex. The patterns of executive impairment attributable to cerebellar damage have been extensively described in the past 15 years, but there has been no assessment of the efficacy of rehabilitation in this patient population. Here, the use of a cognitive rehabilitation technique, Goal Management Training, in a patient with persisting executive dysfunction after a right cerebellar hemorrhage is described. The patient made and maintained modest gains on measures of sustained attention, planning, and organization that translated into significant improvement in real-life functioning. This is the first report on the rehabilitation of impaired executive functioning following focal damage to the cerebellum and in the presence of intact frontal cortex.

To describe the functional outcome of 19 patients with anterior communicating artery aneurysm following the completion of an inter-disciplinary out-patient rehabilitation programme.Retrospective descriptive study.Community-based inter-disciplinary outpatient programme.n = 19; consecutive referred sample, mean 182 days post-onset; in-patient rehabilitation completed.Inter-disciplinary treatment of functional activities; 2-5 hours/day, 3-5 days/week; mean duration: 55-57 days.Supervision rating scale (SRS) and change in prevalence at admission and discharge of executive impairments, memory, confabulation, apathy, initiation, social inappropriateness and incontinence.Sixty per cent of the patients showed a clinically significant improvement in their SRS from requiring full-time supervision to part-time supervision. Change in SRS was correlated with change in the impairments of executive function, memory and confabulation.Although pervasive impairments associated with this disorder may limit capacity for even moderate independence, substantial reduction in direct supervision by family members may be achieved.

Background: Investigations of cognitive deficits after frontal lobe damage have commonly relied on multidimensional tests and relatively coarse specification of lesion anatomy. Some form of impairment in attention is often asserted to cause the revealed deficits.Objective: To describe a disorder of attention in patients with frontal damage using a theoretical model of the fundamental cognitive processes that underlie attention.Methods: The ability to perform a task of concentrated responding was studied in 43 patients with well-defined chronic frontal lesions and 38 control subjects using a continuous reaction time (RT) test. Performance measures were mean RT, RT across blocks of the test, and errors. Lesion measures were coarse localization and a hot-spot analysis to detect finer grained lesion effects.Results: Only patients with lesions in the right superomedial (SM) frontal regions had significantly prolonged RT consistently across the entire test. The critical lesion was in Brodmann’s areas 24, 32, 9, and 46 days and in the adjacent corpus callosum. Patients with lesions in left lateral frontal (LL) regions made significantly more errors on the 20% of trials in the first block. The critical lesion was in areas 44, 45, and 47/12.Conclusion: Concentrating attention to respond is affected by lesions in two different frontal regions for reasons that reflect impairments in different cognitive processes. Right superomedial lesions cause an insufficient energizing of attention to respond. Left lateral lesions cause defective setting of specific stimulus-response contingencies. Constrained tests of attention can demonstrate impairments in specific cognitive operations following lesions to different regions of the frontal lobes.

Background: Although cardiac arrest (CA) is commonly cited as a cause of amnesia, patients referred to the authors’ center with a diagnosis of “amnesia” after CA rarely have isolated memory deficits. Objective: To determine whether CA is a cause of pure amnesia and to assess patterns of cognitive deficits after CA. Methods: The authors used cognitive assessment of 11 consecutive patients referred for memory deficits after CA, targeted at deficit domains identified in the literature reviews, and analysis of specific case reports and prospective studies of cognition after CA. Results: The most common pattern of impairment in their patients was a combination of memory and motor deficits with variable executive impairment. No patient had isolated memory impairment. The case reports do not support the claim that isolated amnesia is a residual of CA; most cases of isolated amnesia are caused by subacute episodes of anoxia or excitotoxic injury. The prospective reports identify highly variable patterns of impairment, but isolated amnesia remains rare. Conclusions: Diffuse, sudden ischemic-hypoxic injury caused by cardiac arrest (CA) does not preferentially damage memory systems. Subacute or stepwise hypoxic or excitotoxic injury may cause isolated hippocampal injury and amnesia. The common pattern of impairment in the postacute phase after CA is a combination of memory, subtle motor, and variable executive deficits.

The hypothesis that prefrontal cortex plays a critical role in accurate predictions of episodic memory performance was tested using the feeling-of-knowing (FOK) paradigm. Fourteen patients with a broad spectrum of damage to the frontal cortex and matched controls read sentences and later were tested for recall memory, confidence judgments, and FOK accuracy using as cues the sentences with the final word missing. While frontal patients were impaired at recall and recognition memory, they were able to make accurate confidence judgments about their recall attempts. By contrast, as a group, the patients were markedly impaired in the accuracy of their prospective FOK judgments. Lesion analysis of frontal patients with clear FOK impairment revealed an overlapping region of damage in right medial prefrontal cortex. These findings provide functional and anatomical evidence for a dissociation between recall confidence and prospective memory monitoring and are discussed in terms of familiarity and access theories of FOK predictions.

The causes of variability of performance by individual subjects have rarely been investigated, although excessive variability or inconsistency may be a functionally significant factor for many real-life activities. Our objective was to determine whether patients with focal frontal brain lesions have excessive individual performance variability. Thirty-six patients with focal frontal (n=25) or non-frontal (n=11) lesions were compared with 12 control subjects on different measures of intra-individual variability: dispersion within a testing session; and consistency across testing sessions. Four reaction time tasks, varying in levels of complexity and based on a model of detection using feature integration, were administered. Following the first test session, 22 patients and 10 controls returned for two subsequent test sessions, which permitted the assessment of consistency of performance. Measures of abnormal dispersion of performance on these tests were observed in frontal patients only (except those with exclusively inferior medial damage). Disturbances in consistency of performance were observed primarily in patients with frontal lesions. Damage to the frontal lobes impairs the stability of cognitive performance. Damage to different frontal regions causes different profiles of abnormal variability. Fluctuations in performance of a task may underlie some of the reported difficulties in daily tasks reported by patients with frontal injuries.

To retrospectively evaluate gastrostomy placement in patients with amyotrophic lateral sclerosis (ALS) to determine the insertion method of choice.During 3(1/2) years, 36 patients with ALS (19 men, 17 women; mean age, 54 years; age range, 37-69 years) underwent gastrostomy. Twenty patients were primarily referred for percutaneous endoscopic gastrostomy (PEG) and 16 for percutaneous radiologic gastrostomy (PRG). Gastrostomy method, success rate of each technique, and reason for procedure failure were reviewed in each patient. Forced vital capacity (FVC) prior to gastrostomy was recorded. PEG was performed with a pull-through technique after transillumination of the abdominal wall. PRG was performed with fluoroscopic guidance and T-fastener gastropexy. A log-rank test was used to compare survival rates after PRG and PEG, and a Wilcoxon rank sum test was used to evaluate the influence of declining FVC on PEG success. The Kaplan-Meier product limit method was used to estimate survival probabilities.Of the 20 patients referred for PEG, 11 had successful results. The nine failures (45%) resulted from failure to transilluminate the abdominal wall. All 16 patients primarily referred for PRG underwent successful gastrostomy. The nine patients in whom PEG failed underwent subsequent successful PRG. In patients with diaphragmatic palsy and a high subcostal stomach, an angled subcostal approach (n = 6) or intercostal approach (n = 2) was required at PRG. One death occurred in the PEG group (9%) because of procedure-related aspiration, and a second patient from the PEG group required laparotomy for postprocedural peritonitis. One death occurred in the PRG group (4%) because of inadvertent placement of the feeding tube in the peritoneal cavity. There was no significant difference between PEG and PRG in patient survival. FVC did not have a statistically significant influence on PEG failure.Results show PRG to be the method of choice.

Objective: Patients with left neglect on line bisection show normal implicit sensitivity to manipulations of both the stimulus and the visual background. Three experiments were designed to define this sensitivity more exactly. Methods: Normal controls and patients with left neglect performed a series of horizontal line bisection tasks. Independent variables were the configurations of the backgrounds for the line—rectangle, square, circle, left and right pointing isosceles triangles—and whether the background was the shape of the piece of paper or an outline drawn on a standard piece of paper. In a separate experiment different components of the triangle were outlined on a piece of paper. Deviation from true midpoint was calculated. Results: Simply placing the target lines in a symmetric background such as a square or circle did not reliably reduce neglect. A triangle asymmetric in the horizontal plane caused a shift in bisection away from the triangle9s vertex. With right pointing triangles the perceived midpoint shifted to the left of true centre (crossed over). The effects of the triangles were comparable in the patients and the controls when controlled for baseline bisection bias. The critical components of the triangles were the angular legs. This effect of background was not influenced by lesion site or by hemianopia. Conclusions: Patients with left visual neglect remain sensitive to covert manipulations of the visual background that implicitly shift the perceived midpoint of a horizontal line. This effect is strong enough to eliminate neglect on a bisection task. The mechanism of this effect is expressed through preattentive visual capacities.

There were three primary objectives: to examine the usefulness of the Stroop interference effect as a measure of frontal lobe function; to investigate the possibility of distinct lesion effects for word reading or color naming; and to specifically determine the brain regions necessary for the performance of the incongruent condition. Fifty-one patients with single focal brain lesions in frontal and non-frontal regions and 26 normal control subjects (CTL) were administered the word reading, color naming and incongruent conditions of the Stroop task. Only frontal lesions produced significant impairment. Patients with posterior lesions were not significantly deficient in any condition. Damage to the left dorsolateral frontal lobe resulted in increased errors and slowness in response speed for color naming. Contrary to Perret (Neuropsychology, 1974; 12: 323-330), lesions of the left frontal lobe did not result in a selective interference deficit on the Stroop incongruent condition. Rather, bilateral superior medial frontal damage was associated with increased errors and slowness in response time for the incongruent condition. This result is interpreted as failure of maintenance of consistent activation of the intended response in the incongruent Stroop condition. The results and conclusion are compatible with the prevalent theories of both the Stroop effect and the role of the superior medial frontal regions. The role of the anterior cingulate cortex on performance of the Stroop task is likely related to task and patient context.

A location-based ('select-what, respond-where') priming task was used to examine three measures of selective attention (interference (INT), negative priming (NP), and inhibition of return (IOR)) as a function of focal brain pathology and the complexity of target selection. Control subjects showed different patterns of performance for the three attentional measures as a function of complexity, suggesting some independence among INT, NP, and IOR. Brain-damaged subjects showed significant response slowing, as well as a number of lesion-specific attentional abnormalities. Right frontal (including bifrontal) damage resulted in proportionally increased interference related to task complexity. Left posterior damage increased IOR in the most complex task, while left frontal damage reversed the control pattern of IOR as a function of complexity. Right hemisphere (right posterior and right frontal damage) pathology resulted in a virtual loss of negative priming at all levels of task complexity; left and bifrontal damage resulted in diminished NP only related to increases in the complexity of selection. INT, NP, and IOR are mediated by different brain regions and their expression can be modulated by the complexity of the selection task.

We examined the hypothesis that, on verbal fluency, clustering (i.e. generating words within subcategories) is related to temporal-lobe functioning, whereas switching (i.e. shifting between subcategories) is related to frontal-lobe functioning. Tests of phonemic and semantic fluency were administered to 53 patients with focal frontal-lobe lesions (FL), 23 patients with unilateral temporal-lobe lesions (TL) and 55 matched controls. Performance by FL patients was consistent with our hypothesis: in comparison to controls, patients with left-dorsolateral or superior-medial frontal lesions switched less frequently and produced normal cluster sizes on both phonemic and semantic fluency. Performance by TL patients was not consistent across fluency tasks and provided partial support for our hypothesis. On phonemic fluency, TL patients were unimpaired on both switching and clustering. On semantic fluency, TL patients were impaired on switching in comparison to controls and left TL patients produced smaller clusters than right TL patients. The best indices for discriminating the patient groups, therefore, were phonemic-fluency switching (impaired only with frontal lesions) and semantic-fluency clustering (impaired only with temporal-lobe lesions).

To characterize the frequency of recovery of arm paresis in patients with traumatic brain injury (TBI) admitted to rehabilitation.Retrospective review identifying a cohort of patients with moderate or severe arm paresis after TBI followed at least 6 months postinjury.Freestanding acute rehabilitation hospital TBI unit.Forty-four patients with moderate to severe arm paresis were selected from 264 consecutive admissions and characterized by injury pathology subtype, injury severity (duration of unconsciousness [loss of consciousness, LOC] and posttraumatic amnesia [PTA]), age, and level of paresis according to Brunnstrom Stages of Recovery (BS 1 to 6). Patient groups with and without arm paresis were compared according to these variables (t tests and chi(2)).Recovery of arm paresis to isolated motor function (BS 5 or 6) and time to achieve recovery. Recovered and nonrecovered patients were compared (Mann-Whitney, t tests, and chi(2)) on injury severity, initial level of paresis, age, time to rehabilitation admission, and pathology subtype. Time to recovery was compared for patients at different levels of initial paresis, ranges of LOC, and pathology subtypes (Mann-Whitney and Kruskal-Wallis tests).Forty-four patients (17%) had moderate (BS 3 to 4) or severe (BS 1 to 2) paresis at rehabilitation admission. They were more severely injured than nonparetic patients based on longer LOC (p.002) and PTA (p.009). Thirty-six patients (82%) recovered by 6 months; 72% of these recovered by 2 months. If still paretic at 2 months, only 56% recovered. Mean recovery time was 6.9 weeks (SD, 6.1) from injury. Time to recovery was best predicted by initial level of paresis and injury severity (r2 = .48), but not age. Patients with diffuse injury tended towards a more protracted recovery (7.9 weeks, SD 6.5) than patients with focal injury (4.2 weeks, SD 3.9) (p = .08) and only those with diffuse injury showed further recovery after 3 months.Arm paresis after TBI is relatively infrequent. Most patients recover by 2 months but later recovery is possible, especially in patients with primarily diffuse brain damage. Recovery is highly related to initial impairment, injury severity, and distribution of brain injury.

Anomalous lateralization of cognitive functions is observed in a small percentage of right-handed patients with unilateral brain damage, either crossed aphasia (aphasia after right brain damage) or “crossed nonaphasia” (left brain damage without aphasia but with visuospatial and other deficits typical of right brain damage). No comprehensive theory of these anomalous cases has been proposed. Nine new right-handed cases (plus one left-handed case) were analyzed and the literature was reviewed. The dramatically anomalous organization of cognitive functions is best explained by random lateralization of all cognitive functions in a small subset of the population. The RS theory of cerebral dominance can account for this pattern of anomalies in right-handers and may account for the most common patterns of dominance observed in left-handers.

In the current study, we investigated whether standard assessment techniques of visuospatial neglect are sensitive to detecting dissociable subtypes. We administered a battery of tasks commonly used to detect the presence of visuospatial neglect to 120 patients with unilateral right hemisphere infarcts and, in most cases, performed a systematic analysis of their lesions to quantify and localize brain damage. Using a factor analysis, we discovered seven relatively independent constructs, three of which were specifically related to the presence of left hemispatial neglect: Left Attentional Processing, Line Bisection. and Word Reading. Impairments in two of these factors. Left Attentional Processing and Line Bisection, occurred together in most cases but also occurred independently in 38 cases. There were no cases in whom Word Reading was present without concomitant deficits in one or the other two factors. These three factors could not be distinguished neuroanatomically; that is, lesions were equally likely in the temporal/parietal cortex, dorsolateral frontal cortex, or in deep frontal structures. These data confirm the notion that hemispatial neglect is a complex and multifaceted disorder composed of cognitively independent processes. These processes, however, cannot be dissociated neuroanatomically based on currently available assessment techniques. (JINS, 1996, 2, 441–451.)

Urinary incontinence (UI) after stroke is common and associated with overall poor functional outcomes.There is controversy regarding which factors contribute to incontinence after stroke and which factors may be predictive of recovery of continence. This study investigated consecutive stroke admissions to an inpatient rehabilitation hospital and evaluated the impact of several pre-selected factors on the presence of UI and its recovery. We also studied the impact of UI on outcome in terms of functional abilities with the Functional Independence Measure (FIM) and in terms of disposition. UI on admission was associated with severe functional impairment with large infarctions and was probably caused by general severity rather than specific impairment of neuromicturition control. Patients with less impairment (admission FIM >60) and small vessel strokes were likely to recover continence. UI on admission had a negative impact on outcome.NEUROLOGY 1996;47: 659-663

Accurate outcome prediction following stroke is important for proper delivery of poststroke care.It has been difficult to determine specific factors that provide reliable and accurate predictions of outcome, particularly for patients with intermediate deficit severities. Age and severity of deficit have repeatedly been found to be most reliable, but only as rough estimates and for patients at either extreme of the disability spectrum. This paper reports a prospective study of consecutive rehabilitation admissions (N = 536) to determine the influence of preselected factors. Outcome was analyzed in terms of functional improvement and disposition. Patients younger than 55 years or with an admission Functional Independence Measure (FIM) greater than 80 almost universally went home. Admission FIMs less than 40 were associated with nearly certain nursing home discharge. The comprehensive FIM score was a stronger predictor of outcome than motor impairment in isolation. An admission FIM of 60 or greater was associated with a higher probability of functional improvement during rehabilitation. Small-vessel strokes had the best outcome. Intracerebral hemorrhages improved more than ischemic strokes but more slowly. Right hemisphere lesions did worse than left. Comorbidities influenced outcome only when several conditions accumulated. The absence of a committed caregiver at home increased the risk of nursing home discharge. Suggestions for rehabilitation triage are given.NEUROLOGY 1996;47: 388-392

This study compared the post-CVA speech of a patient presenting with the foreign accent syndrome (FAS) to both a premorbid baseline for that patient and to similarly analyzed data from an earlier reported case of FAS. The object of this research was to provide quantitative acoustic data to determine whether: (1) the constellation of phonetic features associated with FAS is the same across patients and (2) a common neural mechanism underlies FAS. Acoustic parameters investigated included features of consonant production (voicing, place and manner of articulation), vowel production (formant frequency and duration), and prosody. Results supported the characterization of FAS patients as having a “generic” foreign accent and the hypothesis that FAS deficits are qualitatively different from that of Broca's aphasia. However, comparison of this case with recent studies revealed the extent to which the constellation of phonetic features may vary among FAS patients, challenging the notion that a general prosodic disturbance is the sole underlying mechanism in FAS.

Word production was examined in four aphasics diagnosed acutely with neologistic jargon and who displayed impairment to the lexical stage of phonological production (Kohn & Smith, 1993, 1994a). To investigate the major source of their nonword errors (i.e., neologisms, phonemic paraphasias), single word production was tested at three different times over the first 6 months postonset, with one subject receiving additional testing at 14 months postonset. Two subjects showed signs of recovery to the phonological output system with respect to: (1) improved word production scores, (2) increased frequency of phonemic paraphasias versus neologisms, and (3) increased production of target phonemes. These subjects also displayed above-chance production of target phonemes and no significant tendency to perseverate phonemes across picture-naming trials. It was argued that this pattern reflects a resolving disturbance in retrieving entries from the phonological lexicon. The other two subjects showed no improvement in word production. They also consistently produced target phonemes at chance levels and had a tendency to perseverate phonemes across picture-naming trials. This static pattern of performance was considered to reflect loss of information from the phonological lexicon. The neuroanatomical damage sustained by each case was consistent with these two recovery patterns.

Impairment on verbal fluency tasks has been one of the more consistently reported neuropsychological findings after cerebellar lesions, but it has not been uniformly observed and the possible underlying cognitive basis has not been investigated. We tested twenty-two patients with chronic, unilateral cerebellar lesions (12 Left, 10 Right) and thirty controls on phonemic and semantic fluency tasks. We measured total words produced, words produced in the initial 15 seconds, errors and strategy switches. In the phonemic fluency task, the right cerebellar lesion (RC) group produced significantly fewer words compared to the left cerebellar lesion (LC) group and healthy controls, particularly over the first 15 seconds of the task with no increase in errors and significantly fewer switches over the entire task. In the semantic fluency task there was only a modest decrease in total words in the RC group compared to controls. RC lesions impair fluency with many of the same performance characteristics as left prefrontal lesions. This supports the hypotheses of a prefrontal-lateral cerebellar system for modulation of attention/executive or strategy demanding tasks.

Introduction It has been asserted that damage to the cerebellum produces a specific pattern of cognitive deficits, but clinical studies have had ambiguous results. There remains particular uncertainty about the effects of focal cerebellar injuries on cognition in adults. Clinical reports and anatomical connectivity studies have suggested a possible functional convergence of frontal lobes and cerebellum. This investigation was designed to assess whether focal cerebellar injuries in adults would cause impairment on tasks previously demonstrated to be sensitive to prefrontal lesions. Method We investigated this question in 32 adults with either stroke or resection of benign tumours and 36 healthy control subjects. Patients underwent standard and experimental cognitive testing and an assessment of general health and well-being at least 3 months post onset. Results The group with right cerebellar lesions had lower performance on some tests of response control and verbal fluency than the controls and also the patients with left cerebellar lesions. On most tests, including most of the experimental tests sensitive to prefrontal lesions, the patients had no significant difference from the controls. The patient groups reported no health or functional decline. Conclusions These results and the bulk of the clinical literature suggest that damage to some cerebellar sites may have specific cognitive consequences, but the cognitive impairment after focal cerebellar injury in adults is mild or transient. After the acute epoch, demonstration of deficits may require more demanding probes of specific domains of cognition.

Background and Purpose— Previous studies have shown motor impairment after a stroke relates to lesion size and location, but unexplained variability in recovery still exists. In this study, we used lesion-mapping techniques in combination with diffusion tensor imaging to quantitatively test the hypothesis that motor recovery in patients with chronic stroke is inversely related to the proportion of the corticospinal tract (CST) affected by the lesion. Methods— We studied 50 patients with chronic stroke, all of whom presented with moderate to severe motor impairments in the acute stage, using high-resolution anatomic MRI. We evaluated the degree of motor impairment with the Upper Extremity module of the Fugl-Meyer Assessment. To analyze the relationship between CST damage and impairment scores, we calculated a CST-lesion load for each patient by overlaying the patient’s lesion map with a probabilistic tract derived from diffusion tensor images of age-matched healthy subjects. Results— CST-lesion load was a significant predictor of motor deficit. Infarct size, despite correlating with motor scores, did not significantly predict impairment. Conclusions— Our results show the degree of functional motor deficit after a stroke is highly dependent on the overlap of the lesion with the CST and not lesion size per se. In the future, automated calculation of CST-lesion load may allow more precise prediction of motor impairment after stroke.

Phonological agraphia is a neurolinguistically specific profile of spelling impairment. It is characterized by an impairment in spelling pronounceable pseudowords (‘sild’) and by an impairment in spelling real words related to their familiarity, length, and often, part of speech (Shallice, 1981 ; Roeltgen, 1985 ; Bub & Chertkow, 1988) . We report two cases of phonological agraphia, each with a different lesion profile. Analysis of the small number of published cases that include lesion data, plus our own cases, suggests that phonological agraphia can be produced by lesions in a wide range of perisylvian cortical regions that have in common some role in central phonological processes.

Outcome studies from post-acute cognitive rehabilitation programmes vary widely and mostly emphasize changes in neuropsychological measures. More recently, the functional outcomes of patients following cognitive rehabilitation have been reported. This study describes the functional outcomes of 42 traumatically brain-injured patients (29 male, 13 female: average age 28.6 years, time post-injury 50.3 months) following treatment in a structured out-patient post-acute cognitive rehabilitation programme. The programme consisted of a minimum of 6 weeks of treatment and emphasized improvement of the patients' real-life functional abilities and psychological support. The treatment goals were individually established for each patient. Patient improvement was determined by the accomplishment of treatment goals and differences in pre- and post-treatment functional measures and speech pathology cognitive measures. Follow-up at 6, 12 and 18 months determined the maintenance of treatment effects. There was a significant improvement on patients' functional measures after treatment. Cognitive measures were not significantly different after treatment, but there was a trend towards improvement. Functional improvements were independent of age, neuropathological category, injury severity and time post-injury. It is concluded that post-acute traumatic brain injury treatment aimed at retraining real-life functional abilities exclusive of specific cognitive remediation can lead to long-term improvements in independence.

That the left prefrontal cortex has a critical role setting response criteria for numerous tasks has been well established, but gaps remain in our understanding of the brain mechanisms of task-setting. We aimed at (i) testing the involvement of this region in setting the criteria for a non-response and (ii) assessing functional connectivity between this and other brain regions involved in task-setting. Fourteen young participants performed a go/nogo task during functional magnetic resonance imaging. The task included two nogo visual stimuli which elicit a high (distractor) or a low (other) tendency to respond, respectively. Two task blocks were examined to assess learning the criteria. First, a multivariate Partial Least Squares (PLS) analysis identified brain regions that co-varied with task conditions, as expressed by two significant Latent Variables (LVs). One LV distinguished go and nogo stimuli. The other LV identified regions involved in the first block when the criteria not to respond to distractors were established. The left prefrontal region was prominently involved. Second, a left ventrolateral prefrontal area was selected from this LV as a seed region to perform functional connectivity using a multi-block PLS analysis. Results showed a distributed network functionally connected with the seed, including superior medial prefrontal and left superior parietal regions. These findings extend our understanding of task-setting along the following dimensions: 1) even when a task requires withholding a response, the left prefrontal cortex has a critical role in setting criteria, and 2) this region responds to the task demands within a distinctive functional network.

Background: Lesions of the frontal lobes may impair the capacity of patients to control otherwise intact cognitive operations in the face of ambiguous sensory input or conflicting possible responses. Objective: To address the question of whether focal lesions in different regions of the frontal lobes produced specific impairments in cognitive control. Methods: We evaluated 42 patients with chronic frontal lesions and 38 control subjects on a modified Stroop test that allowed measurement of reaction times and errors. Planned, stratified analyses permitted identification of discrete frontal lesions that are critical for impaired performance. Results: Lesions of the left ventrolateral region produced an increased number of incorrect responses to distractors. Lesions of a large portion of the right superior medial region, including anterior cingulate, supplementary motor area (SMA), pre-SMA, and dorsolateral areas, caused a slow reaction time and a decreased number of correct responses to targets. Conclusion: Lesions in two distinct frontal regions impair cognitive control for a Stroop task, and the mechanisms of impairment are specific to the region of injury. This is support for a general proposal that the supervisory system is constructed of distinct subsystems.

PUBLISHED, This study provides an introduction to, and overview of, several papers that resulted from a randomized control trial that evaluated a new cognitive rehabilitation protocol. The program was designed to improve general strategic abilities in ways that would be expressed in a broad range of functional domains. The trial, which was conducted on a sample of older adults who had experienced normal age-related cognitive decline, assessed performance in the following domains: memory, goal management, and psychosocial status. The general rationale for the trial, the overall experimental design, and the approach to statistical analyses that are relevant to each paper are described here. The results for each functional domain are reported in separate papers in this series (JINS, 2007, 13, 120?131.)

The presence, and nature, of any role of the cerebellum in complex, non-motor behaviors is only beginning to be uncovered. We investigated the non-spatial temporal dynamics of attention in 11 patients with chronic focal lesions to the cerebellum using a rapid serial visual presentation task known as the attentional blink paradigm. In this task two targets are embedded in a letter stream presented at central fixation for identification and the delay between the targets is manipulated. Patients demonstrated an unequivocal disturbance in rapid visual attention as indicated by an increased magnitude of the attentional blink (i.e., more impaired at detecting target 2 when presented in close contiguity to target 1) compared to 13 healthy controls. The attentional blink effect was not significantly protracted in our patients, suggesting a time-limited deficit in resource allocation during temporally demanding stimulus processing conditions. Recovery rate from the attentional blink was the same for our patients and controls implying intact selective attention following cerebellar damage. Because of the experimental design, the results of the present study could not be accounted for by motor dysfunction or saccadic dysmetria. These data provide evidence implicating the cerebellum as a critical node in the neuroanatomical network underlying visuotemporal attention and provide further evidence for the role of the cerebellum in non-motor behaviors.

Sustained counting (or temporal numerosity judgements) has been one of the key means of investigating anterior attentional processes. Forty-three patients with localised lesions to the frontal lobes were assessed on two tests of the ability to count the number (8–22) of stimuli presented at either a slow (roughly one per 3 sec) or fast (roughly three per sec) rate. Patients with lesions to the Superior Medial (SM) region (particularly Brodmann areas 24, 32, and 9) were impaired both in the Slow condition and also in the Fast condition, where they underestimated the number of stimuli. Patients with Right Lateral (RL) lesions (8, 45, and 46) also had difficulties in the Fast condition, especially when the number of targets was greater than 15. The results are considered from the perspectives of alternative positions on anterior attentional processes developed by Posner and Petersen (1990) and by Stuss et al. (1995). The most plausible interpretation is in terms of energising processes which involve the SM frontal cortex and monitoring processes which involve the RL frontal cortex.

We studied motor representation in patients who recovered well following a stroke. Eighteen right-handed stroke patients and eleven age-matched control subjects underwent functional Magnetic Resonance Imaging (fMRI) while performing unimanual index finger (abduction-adduction) and wrist movements (flexion-extension) using their recovered and non-affected hand. A subset of these patients underwent Transcranial Magnetic Stimulation (TMS) to elicit motor evoked potentials (MEP) in the first dorsal interosseous muscle of both hands. Imaging results suggest that good recovery utilizes both ipsi- and contralesional resources, although results differ for wrist and index finger movements. Wrist movements of the recovered arm resulted in significantly greater activation of the contralateral (lesional) and ipsilateral (contralesional) primary sensorimotor cortex (SM1), while comparing patients to control subjects performing the same task. In contrast, recovered index finger movements recruited a larger motor network, including the contralateral SM1, Supplementary Motor Area (SMA) and cerebellum when patients were compared to control subjects. TMS of the lesional hemisphere but not of the contralesional hemisphere induced MEPs in the recovered hand. TMS parameters also revealed greater transcallosal inhibition, from the contralesional to the lesional hemisphere than in the reverse direction. Disinhibition of the contralesional hemisphere observed in a subgroup of our patients suggests persistent alterations in intracortical and transcallosal (interhemispheric) interactions, despite complete functional recovery.

Background Central neurogenic hyperventilation is a rare condition with poorly understood pathophysiology. Objective To describe a patient with central neurogenic hyperventilation caused by an infiltrative brainstem lymphoma. Conclusion Based on analysis of this patient and other case reports, we propose that central neurogenic hyperventilation is uniquely the result of infiltrative tumors that stimulate pontine respiratory centers and central chemoreceptors.

This study examined the performance of 32 normal subjects and 39 patients with focal lesions of the frontal lobes on two simple timing tasks-responding in time with a tone that regularly repeated at a rate of once every 1.5s, and then maintaining the same regular response rhythm without any external stimulus. The hypothesis was that lesions to the right prefrontal cortex would disrupt timing performance. The two main findings were (1) an abnormally high variability in the timing performance (both self-timed and tone-timed) of patients with lesions to the right lateral frontal lobe, particularly involving Brodmann area 45 and subjacent regions of the basal ganglia; (2) an increase in the variability of timing performance as the task continued in patients with lesions to the superior medial regions of the frontal lobe. These findings indicate that the right lateral frontal lobe is crucially involved in the ongoing control of timed behavior, either because of its role in generating time intervals or in monitoring the passage of these intervals. In contrast, the superior medial regions of the frontal lobe are necessary to maintain consistent timing performance over prolonged periods of time.

Emotional synesthesia is a condition in which specific sensory stimuli are consistently and involuntarily associated with emotional responses.1 There is a very small number of reports of subjects with these stereotyped emotion-sensation pairings. One report described a subject in whom tactile stimulation from different textures (e.g., denim) elicited affective experiences (e.g., feelings of depression).2 Others have described emotional synesthetic associations to grapheme-color perceptions3 and to written names of acquaintances.1 Because there is such a small amount of literature, all in normal subjects with long histories of synesthesia, the neural substrates are unknown. There is a single report of acquired synesthesia: a tingling sensation elicited by sounds, but without emotional synesthesia, after a thalamic infarction.4 We report on the only known case of acquired emotional synesthesia after a focal thalamic lesion, providing a possible window into the neural substrate of this condition.

Oropharyngeal dysphagia is highly prevalent in amyotrophic lateral sclerosis (ALS). Patients with dysphagia and weight loss are frequently offered gastrostomy. Although the neurological basis of dysphagia in ALS is complex, there are currently no specifically validated scales for dysphagia in ALS, and the reliability of existing generic scales has not been assessed.We undertook a prospective study of 25 patients who fulfilled the criteria for definite or probable ALS. We examined the reliability of the Dysphagia Outcome Severity Scale (DOSS) and the Aspiration-Penetration Rating Scale (APRS) and the correlation between these scales and the Norris ALS Scale and ALS Functional Rating Scale-R (ALS FRS-R).Using the Pearson Product-Moment Correlation, an expected high linear association between the two disease specific neurological scales was demonstrated. Both dysphagia scales were found to be reliable. Interrelationship evaluation showed a low association between Norris and ALS FRS-R scores and DOSS and APRS. However, examination found specific subsections to be significantly correlated, particularly the Norris bulbar sections (NBS) and the DOSS.Generic dysphagia scales are reliable indicators of dysphagia in ALS. The bulbar components of the ALS specific scales is sensitive to dysphagia. The bulbar section of the Norris scale can be utilised as an independent and reliable indicator of the severity of dysphagia in ALS. In the absence of availability of detailed swallowing assessment using videofluoroscopy, these scales, i.e., the Norris and to a lesser degree the ALS FRS-R bulbar sections, are adequate to diagnose and follow clinically significant dysphagia in ALS, and can be used as an indicator for dysphagia treatment initiation.

To identify variables that are predictive of independent ambulation after traumatic brain injury (TBI) and to define the time course of recovery.Retrospective review of consecutive admissions of patients with severe TBI over a 32-month period.Brain injury unit in an acute, inpatient rehabilitation hospital.Of 264 patients screened, 116 met criteria that included the ability to participate in motor and functional evaluation on admission to acute rehabilitation, and the absence of other neurologic disorders or fractures that affect one's ability to ambulate.Inpatient rehabilitation on a specialized TBI unit by an interdisciplinary team.Main outcome measures Recovery of independent ambulation and time to recover independent ambulation.Of eligible patients, 73.3% achieved independent ambulation by latest follow-up (up to 5.1 mo). Patients who achieved independent ambulation were significantly younger (P.05), had better gait scores on admission (P.05), and tended to be less severely injured-based on duration of posttraumatic amnesia (PTA; P=.058)-than those who did not ambulate independently. There were no differences in recovery based on neuropathologic profile. Mean time to independent ambulation +/- standard deviation was 5.7+/-4.3 weeks; of those achieving independent ambulation, 82.4% did so by 2 months and 94.1% by 3 months. If not independent by 3 months postinjury, patients had a 13.9% chance of recovery. Multivariate regression analysis generated prediction models for time to independent ambulation, using admission FIM instrument scores and age (38% of variance); initial gait score, loss of consciousness, and age (40% of variance); or initial gait score and PTA (58% of variance), when restricted to just those patients with diffuse axonal injury.Most patients with severe TBI achieved independent ambulation; the vast majority did so within 3 months postinjury. Functional measures, injury severity measures, and age can help guide prognosis and expectations for time to recover.

This study examined verbal recognition memory in amnesic patients with frontal lesions (AF), nonamnesic patients with frontal lesions (NAF), and amnesic patients with medial temporal lesions (MT). To examine susceptibility to false alarms, the number of studied words drawn from various categories was varied. The AF and MT groups demonstrated reduced hits and increased false alarms. False alarms were especially elevated when item-specific recollection was strongest in control participants. The NAF group performed indistinguishably from control participants, but several patients showed excessive false alarms in the context of normal hit rates. These patients exhibited impaired monitoring and verification processes. The findings demonstrate that elevated false recognition is not characteristic of all frontal patients and may result from more than 1 underlying mechanism.

Although frontal lobe lesions do not cause classic amnesia, they may disrupt learning and memory in a number of ways. To investigate in finer detail the regions of frontal injury that are associated with impaired learning and to define the cognitive processing deficits specific to each region that disrupt memory, we compared 33 patients with focal frontal injury with patients with non-frontal injury and with normal controls on a standard neuropsychological instrument, the California Verbal Learning Test (CVLT). Subgroups of patients with distinct lesion site profiles were compared in a number of learning measures. All of the subgroups of patients with frontal lesions (with one exception) had inefficient learning due to poor implementation of a strategy of subjective organization. Despite this organizational deficiency, the performance of patients with frontopolar lesions normalized across trials. Only the subgroups with lesions centred either on the left posterior dorsolateral frontal region or the posterior medial frontal region had overall impaired learning and recall. The left posterior dorsolateral frontal group was most significantly impaired on all measures. This recall impairment was secondary to a mild lexical-semantic deficit. A recognition memory deficit in the same group was due to an abnormal response bias. Several groups had a modest increase in perseverative recalls; the underlying mechanisms differed. Disruption of different cognitive processes associated with specific frontal regions underlies the varied patterns of memory impairment. This study has demonstrated even finer differentiations within the frontal region than previously known.

This study evaluated a model of attention that postulates several distinct component processes, each mediated by specific neural systems in the human frontal lobes. A series of reaction time (RT) tests (simple, choice, and prepare) examined the hypothesis that different attentional processes are related to distinct regions within the frontal lobes. These tests were given to 38 patients with frontal lesions and 38 age-matched control subjects. Lesions were localized both by general regions (superior medial, inferior medial, left and right lateral) and by individual architectonic areas. Lesions in the superior medial (SM) frontal lobes, particularly involving areas 24 and 32 on the right, were associated with slow RT in all tests and with failure to decrease RT after a warning signal. Lesions in the right lateral (RL) frontal lobe, centred in area 9/46v, prevented the decrease in RT with increasing foreperiod that was seen in normal subjects and in patients with lesions elsewhere in the frontal lobes. The ability to energize a response for rapid RT, either generally or specifically following a warning stimulus, is sensitive to lesions of the right SM. Monitoring of stimulus occurrence and response behaviour in order to enhance the speed of response to upcoming stimuli is sensitive to RL lesions.

Repetitive movements have been used as motor activation tasks in the investigation of various neurological disorders. To determine the importance of an age-matched control group in such studies we investigated whether there are significant age-related changes in the pattern of cortical activation seen during simple repetitive movements. Sixteen right-handed healthy subjects were studied-8 young and 8 old. Functional magnetic resonance images were acquired while subjects performed a motor task or a nonmovement rest condition. Two continuous motor tasks, index finger abduction/adduction and wrist extension/flexion, were performed by each hand, paced using a metronome. The fMRI data were processed and analyzed with SPM '99. For the between-group comparisons, for each motor task, contralateral primary sensorimotor cortex and premotor cortex had significantly greater activation in the Young group and caudal supplementary motor area had significantly greater activation in the Old group. Ipsilateral sensorimotor cortex was more significantly activated in the Old group for index finger motor tasks of both hands. All noted differences in the Old group were more prominent for the index finger movement and most prominent when using the nondominant hand. In conclusion, there are significant age-related differences in the activation pattern associated with repetitive movements. This may represent compensatory recruitment of motor cortical units in the older subjects as larger differences are noted in the older group during the more difficult motor tasks, those of isolated finger movement and nondominant hand use. This study has important implications for functional imaging experiments of neurological disorders in older subjects.

Patients with focal frontal or nonfrontal lesions were compared with control participants on 4 reaction time (RT) tasks varying in levels of complexity based on a feature-integration model of detection. Superior medial lesions affected simple RT speed. Increasing the demands of feature detection did not differentially affect speed of correct responses among the groups. Frontal structures appear to play little role in correct integration of features during detection. The analysis of error types within the complex task revealed a frontal lobe hemispheric distinction between sensitivity and bias: right dorsolateral-decreased sensitivity; left dorsolateral-altered response bias. The frontal lobes, particularly right dorsolateral, were required to inhibit an incorrect response. There are at least 3 functionally and anatomically separable anterior attentional processes.

Isosceles triangular backgrounds influence line bisection performance in normal control participants and patients with hemispatial neglect. When the triangles are oriented asymmetrically with the vertex in 1 visual field, and the base in the other, the perceived midpoint of horizontal lines within the triangle is shifted towards the base, and away from the vertex. The current study examines this illusion further by systematically varying the extent of the triangle presented. With only fragments of the triangle in the background of the line, the vertex is the critical component driving the illusory shift in perceived midpoint. Patients with neglect and controls are equally sensitive to the illusion. Similar geometric illusions that are also intact in neglect, along with these results, suggest that preattentive, implicit visual processing is preserved in neglect and drives these illusions.

Current assessments do not provide reliable factors predictive of outcome from stroke for stroke survivors of intermediate age and severity of deficit. We sought to investigate whether early rate of functional improvement can facilitate prediction of functional outcome, length of stay, and disposition beyond that afforded by age and initial severity of deficit. Prospective study of consecutive admissions to acute rehabilitation (N = 244) with diagnosis of ischemic or hemorrhagic stroke. Independent measures were age, marital status, living situation, social situation, lag from symptom onset to rehabilitation, stroke type, admission score on the Functional Independence Measure (FIM), rate of FIM change (ROFC) as assessed by the best weekly FIM change in the first 3 weeks of rehabilitation. Dependent measures were functional status on discharge as assessed by a modification of Steinman's method, length of stay, and discharge disposition. Logistic regression analyses on each of the dependent measures identified significant factors, and interactions of significant factors were assessed by analysis of variance on continuous dependent variables. Cross-tabulations using significant factors from the logistic regression analyses were performed to identify groups with homogeneous outcomes. Groups with >80% homogeneity were considered likely to have predictive value. Discharge functional status: Admission FIM (AFIM) again fractionated the population into groups with poor outcome (AFIM 70 achieved nondependence), and an intermediate group with unpredictable outcome. In this intermediate group, ROFC had significant effect only for a small number of patients (n = 9) with rapid improvement (ROFC >25) who achieved nondependence. LOS: AFIM >70 had less than average LOS, ROFC = 10–15 FIM/week had longer than average LOS. LOS was significantly prolonged in patients with poor outcomes. Disposition: AFIM >70 and age

A 40-year-old man presented with a major nondominant hemisphere stroke syndrome after a road traffic accident. Cranial computed tomography scan revealed an extensive right hemisphere infarction involving the entire anterior and middle cerebral artery territories. Duplex Doppler ultrasound and cerebral angiography revealed bilateral internal carotid artery dissection with evidence of underlying fibromuscular dysplasia. Anticoagulation with heparin was commenced despite the coexisting large cerebral infarction, with the objective of protecting the uninjured but at-risk left cerebral hemisphere from ischemic injury. Patients with multiple cerebral arterial dissections complicated by cerebral infarction present a significant management dilemma. Our literature review revealed a lack of clear management guidelines for such cases.

Forty-six patients with single focal lesions (35 frontal, 11 nonfrontal) were administered the Wisconsin Card Sorting Test (WCST) under three conditions of test administration. The three conditions varied in the amount of external support provided via specificity of instructions. The WCST, while a multifactorial test, is specifically sensitive to the effects of frontal lobe damage if deficits in language comprehension and visual-spatial search are controlled. There is also specificity of functioning within the frontal lobes: patients with inferior medial frontal lesions, unilateral or bilateral, were not impaired on the standard measures although they had increased loss of set when informed of the sorting categories. Verbal instructions may provide a probe to improve diagnosis and prognosis, assessment of the potential efficacy of treatment, and the time frame of plasticity of specific cognitive operations.

Two patients with severe global amnesia are described who differ in the extent to which they have acquired new semantic information. Patient SS, who has extensive medial temporal lobe damage including the hippocampus as well as surrounding cortical areas, has failed to acquire virtually any new information regarding vocabulary or famous faces that entered the public domain since the onset of his amnesia. In contrast, patient PS, who has a selective lesion of the hippocampus proper, has gained a sense of familiarity of novel vocabulary and famous people, even though her effortful retrieval of this new semantic knowledge remains impaired. These findings extend to amnesia of adult onset, the proposal of Vargha-Khadem and colleagues that in patients with selective hippocampal injury, cortical areas surrounding the hippocampus may play an important role in new semantic learning [Vargha-Khadem, F., Gadian, D.G., Watkins, K. E., Connelly, A., Van Paesschen, W. and Mishkin, M., regarding the importance of the subhippocampal cortices in the mediation of new semantic learning in children with hippocampal lesions, Science, 1997, 277, 376-380].

A patient is reported who suffered hypoxic-ischemic injury causing isolated and eventually partially reversible semantic memory loss. Despite normal MRI findings, single-photon emission CT demonstrated dysfunction in posterior cortical association areas. Semantic memory is the sum of categorical, perceptual, and conceptual knowledge. While not localized in the brain in a strict sense like visual fields, semantic memory is thought to be broadly organized in the posterior association cortices, with a particular focus in the inferior temporal regions. Evidence for this has come from patients with herpes simplex encephalitis, temporo-occipital infarctions, and dementias. This case confirms the importance of these cortical regions for semantic memory. The rapid recovery in this case, as opposed to the encephalitis or infarction cases, suggests an important role for preservation of white matter connections in the region for reconstitution of function. NEUROLOGY 1997;48: 165-173