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Background and Purpose— Intracerebral hemorrhage is a considerable source of morbidity and mortality. This 3-center study describes outcomes of pediatric intracerebral hemorrhage and identifies 2-year neurological outcome predictors. Methods— Children 29 days to 18 years of age presenting with intracerebral hemorrhage from March 2007 to May 2015 were enrolled prospectively. Exclusion criteria included trauma; intracranial tumor; hemorrhagic transformation of arterial ischemic stroke or cerebral sinovenous thrombosis; isolated subdural, epidural, or subarachnoid hemorrhage; and abnormal baseline neurological function. Intracerebral hemorrhage and total brain volumes were measured on neuroimaging. The Pediatric Stroke Outcome Measure assessed outcomes. Results— Sixty-nine children were included (median age: 9.7 years; interquartile range: 2.2–14). Six children (9%) died during hospitalization. Outcomes in survivors were assessed at early follow-up in 98% (median 3.1 months; interquartile range: 3.1–3.8) and at later follow-up in 94% (median: 2.1 years; interquartile range: 1.3–2.8). Over a third had a significant disability at 2 years (Pediatric Stroke Outcome Measure >2). Total Pediatric Stroke Outcome Measure score improved over time ( P =0.0003), paralleling improvements in the sensorimotor subscore ( P =0.0004). Altered mental status (odds ratio, 13; 95% confidence interval, 3.9–46; P P =0.01), and intensive care unit length of stay (odds ratio, 1.1; 95% confidence interval, 1.0–1.2; P =0.002) were significantly associated with poor 2-year outcome. Conclusions— Over one third of children experienced significant disability at 2 years. Improvements in outcomes were driven by recovery of sensorimotor function. Altered mental status, hemorrhage volume ≥4% of total brain volume, and intensive care unit length of stay were independent predictors of significant disability at 2 years.

Background Positive diffusion weighted imaging (DWI) on MRI is associated with increased recurrent stroke risk in TIA patients. Acute MRI aids in TIA risk stratification and diagnosis. Aim To evaluate the feasibility and safety of TIA triage directly from the emergency department (ED) with acute MRI and neurological consultation. Methods Consecutive ED TIA patients assessed by a neurologist underwent acute MRI/MRA of head/neck per protocol and were hospitalized if positive DWI, symptomatic vessel stenosis, or per clinical judgment. Stroke neurologist adjudicated the final TIA diagnosis as definite, possible, or not a cerebrovascular event. Stroke recurrence rates were calculated at 7, 90, 365 days and compared with predicted stroke rates derived from historical DWI and ABCD2 score data. Results One hundred twenty-nine enrolled patients had a mean age of 69 years (±17) and median ABCD2 score of 3 (interquartile range [IQR] 3–4). During triage, 112 (87%) patients underwent acute MRI after a median of 16 h (IQR 10–23) from symptom onset. No patients experienced a recurrent event before imaging. Twenty-four (21%) had positive DWI and 8 (7%) had symptomatic vessel stenosis. Of the total cohort, 83 (64%) were discharged and 46 (36%) were hospitalized. By one-year follow-up, one patient in each group had experienced a stroke. Of 92 patients with MRI and index cerebrovascular event, recurrent stroke rates were 1·1% at 7 and 90 days. These were similar to predicted recurrence rates. Conclusion TIA triage in the ED using a protocol with neurological consultation and acute MRI is feasible and safe. The majority of patients were discharged without hospitalization and rates of recurrent stroke were not higher than predicted.

Previous studies of pediatric intracerebral hemorrhage have investigated isolated intraparenchymal hemorrhage. The authors investigated whether detailed assessment of intraventricular hemorrhage enhanced outcome prediction after intracerebral hemorrhage. They prospectively enrolled 46 children, full-term to 17 years, median age 2.7 years, with spontaneous intraparenchymal hemorrhage and/or intraventricular hemorrhage. Outcome was assessed with the King’s Outcome Scale for Childhood Head Injury. Twenty-six (57%) had intraparenchymal hemorrhage, 10 (22%) had pure intraventricular hemorrhage, and 10 (22%) had both. There were 2 deaths, both with intraparenchymal hemorrhage and intraventricular hemorrhage volume ≥4% of total brain volume. Presence of intraventricular hemorrhage was not associated with poor outcome, but hydrocephalus showed a trend ( P = .09) toward poor outcome. In receiver operating characteristic curve analysis, combined intraparenchymal hemorrhage and intraventricular hemorrhage volume also showed a trend toward better outcome prediction than intraparenchymal hemorrhage volume alone. Although not an independent outcome predictor, future studies should assess intraventricular hemorrhage qualitatively and quantitatively.

There is evidence for different levels of visuospatial processing with their own frames of reference: viewer-centered, stimulus-centered, and object-centered. The neural locus of these levels can be explored by examining lesion location in subjects with unilateral spatial neglect (USN) manifest in these reference frames. Most studies regarding the neural locus of USN have treated it as a homogenous syndrome, resulting in conflicting results. In order to further explore the neural locus of visuospatial processes differentiated by frame of reference, we presented a battery of tests to 171 subjects within 48 hr after right supratentorial ischemic stroke before possible structural and/or functional reorganization. The battery included MR perfusion weighted imaging (which shows hypoperfused regions that may be dysfunctional), diffusion weighted imaging (which reveals areas of infarct or dense ischemia shortly after stroke onset), and tests designed to disambiguate between various types of neglect. Results were consistent with a dorsal/ventral stream distinction in egocentric/allocentric processing. We provide evidence that portions of the dorsal stream of visual processing, including the right supramarginal gyrus, are involved in spatial encoding in egocentric coordinates, whereas parts of the ventral stream (including the posterior inferior temporal gyrus) are involved in allocentric encoding.

Hemispatial neglect has been well established in adults following acute ischemic stroke, but has rarely been investigated in children and young adults following brain injury. It is known that young brains have a tremendous potential for reorganization; however, there is controversy as to whether functions are assumed by the opposite hemisphere, or perilesional areas in the same hemisphere. Patients with intractable epilepsy who undergo hemispherectomy for treatment are missing the entire cortex on one side following surgery. In these patients, only the opposite hemisphere is available to assume function. Therefore, they provide the unique opportunity to determine in what cases the left or right hemisphere can take over the spatial attention functions of the opposite hemisphere following damage. The objective of this study was to determine the incidence and types of hemispatial neglect in children and young adults following both right- and left-sided hemispherectomy; which types of spatial attention functions can be assumed by the opposite hemisphere; and whether factors like their age at time of surgery, handedness, or gender influence recovery.Thirty-two children and young adults who had previously undergone hemispherectomy were administered two tests to evaluate for two types of hemispatial neglect: a gap detection test and a line cancellation test. Egocentric neglect was defined as significantly more omissions of targets on the contralesional versus ipsilesional side of the page (by chi square analysis; p.05). Allocentric neglect was defined as significantly more errors in detecting contralesional versus ipsilesional gaps in circles.Only one of the patients displayed statistically significant hemispatial egocentric neglect on the line cancellation test, and none of the patients displayed statistically significant egocentric or allocentric neglect on the gap detection test.These results imply that reorganization to the contralateral hemisphere occurs peri-hemispherectomy, as there are no perilesional areas to assume function.

Introduction: Unilateral neglect after acute right hemispheric stroke significantly impedes poststroke recovery. We studied patients with right hemispheric stroke to determine whether increasing age was associated with more frequent or more severe neglect. Methods: Eight neglect tests within 5 days of symptom onset (and within 24 hours of admission) were administered to 204 subjects with acute right hemispheric stroke. Size of infarct was measured, and neglect tests were scored as percent error. “Any neglect” was defined by an elevated neglect test score, standardized relative to a group of normal controls. Results: When tested for neglect soon after acute stroke admission, 69.6% of subjects older than 65 years had “any neglect” (defined by comparison to a group of normal controls), compared with 49.4% of subjects aged 65 years and younger ( p = 0.008). For every additional 10 years of age, patients were 1.83 times as likely to have neglect, even after adjusting for diffusion-weighted imaging (DWI) infarct volume and NIH Stroke Scale (NIHSS) score (95% CI 1.38–2.43). In addition, DWI volume and NIHSS independently predicted neglect. Score on virtually all of the neglect tests worsened as an effect of age. Percentage error on a line cancellation task was 3.8% higher for every additional 10 years of age, after adjustment for DWI volume and NIHSS ( p = 0.006). Similar results were found for other neglect tests. Conclusions: Increasing age in patients with acute right hemispheric stroke significantly increases the odds of unilateral neglect as well as severity of neglect, independently of size of the stroke or NIH Stroke Scale score. The reason for this finding in older patients may be because they have more brain atrophy and may be less able to compensate for cerebral infarction, or because they tend to have more cardioembolic strokes, which may be more cortically based.

Hemispatial neglect is a common and disabling consequence of stroke. Previous reports examining the relationship between gender and the incidence of unilateral spatial neglect (USN) have included either a large numbers of patients with few neglect tests or small numbers of patients with multiple tests. To determine if USN was more common and/or severe in men or women, we examined a large group of patients (312 right-handed) within 24 hours of acute right hemisphere ischemic stroke. Multiple spatial neglect tasks were used to increase the sensitivity of neglect detection. No differences based upon gender were observed for the prevalence, severity, or a combined task measure of USN.

Background and Purpose: Diffusion–perfusion mismatch has been used to estimate salvageable tissue and predict potential for recovery in acute stroke. Location of the salvageable tissue may be as important as volume or percentage in predicting potential for recovery of specific functions. Impaired naming, a common and disabling deficit after left hemisphere stroke, is often associated with tissue dysfunction of left Brodmann area (BA) 37, posterior inferior temporal cortex. We tested the hypothesis that the presence of diffusion–perfusion mismatch within left BA 37 predicts probability and extent of short-term improvement of naming. Methods: One hundred five patients with acute left hemisphere ischemic stroke had diffusion-weighted imaging, perfusion-weighted imaging, a test of picture naming, and other language tests at admission and 2 to 4 days later. Linear regression was used to determine whether diffusion–perfusion mismatch in any BA in language cortex, total volume of mismatch, or diffusion or perfusion abnormality predicted degree of improvement in naming by days 3 to 5. Results: The presence of >20% diffusion–perfusion mismatch in left BA 37 and total volumes of diffusion and perfusion abnormality at day 1 each independently predicted degree of improvement in naming. Mismatch in this area did not predict the degree of improvement in other language tests or the NIH Stroke Scale in this study. Conclusions/Relevance: Diffusion–perfusion mismatch in left Brodmann area 37 was strongly associated with acute improvement in naming, independently of volume or percentage of total mismatch or diffusion or perfusion abnormality. These data indicate that mismatch in a particular area is a marker of salvageable tissue and an important predictor of potential for recovery of functions that depend on that area. Location of mismatch before treatment may help to predict potential benefits of reperfusion. GLOSSARY: ADC = apparent diffusion coefficient; BA = Brodmann area; DWI = diffusion-weighted imaging; NIHSS = NIH Stroke Scale; PWI = perfusion-weighted imaging; TE = echo time; TR = repetition time; TTP = time to peak.

A number of previous studies have indicated that Broca's area has an important role in understanding and producing syntactically complex sentences and other language functions. If Broca's area is critical for these functions, then either infarction of Broca's area or temporary hypoperfusion within this region should cause impairment of these functions, at least while the neural tissue is dysfunctional. The opportunity to identify the language functions that depend on Broca's area in a particular individual was provided by a patient with hyperacute stroke who showed selective hypoperfusion, with minimal infarct, in Broca's area, and acutely impaired production of grammatical sentences, comprehension of semantically reversible (but not non-reversible) sentences, spelling, and motor planning of speech articulation. When blood flow was restored to Broca's area, as demonstrated by repeat perfusion weighted imaging, he showed immediate recovery of these language functions. The identification of language functions that were impaired when Broca's area was dysfunctional (due to low blood flow) and recovered when Broca's area was functional again, provides evidence for the critical role of Broca's area in these language functions, at least in this individual.

We identified areas of the brain that are critical for naming pictures of objects, using a new methodology for testing which components of a network of brain regions are essential for that task. We identified areas of hypoperfusion and structural damage with magnetic resonance perfusion- and diffusion-weighted imaging immediately after stroke in 87 individuals with impaired picture naming. These individuals were reimaged after 3–5 d, after a subset of patients underwent intervention to restore normal blood flow, to determine areas of the brain that had reperfused. We identified brain regions in which reperfusion was associated with improvement in picture naming. Restored blood flow to left posterior middle temporal/fusiform gyrus, Broca's area, and/or Wernicke's area accounted for most acute improvement after stroke. Results show that identifying areas of reperfusion that are associated with acute improvement of a function can reveal the brain regions essential for that function.

Background and Purpose— The intracerebral hemorrhage (ICH) score is the most commonly used clinical grading scale for outcome prediction after adult ICH. We created a similar scale in children to inform clinical care and assist in clinical research. Methods— Children, full-term newborns to 18 years, with spontaneous ICH were prospectively enrolled from 2007 to 2012 at 3 centers. The pediatric ICH score was created by identifying factors associated with poor outcome. The score’s ability to detect moderate disability or worse and severe disability or death was examined with sensitivity, specificity, and area under the receiver operating characteristic curve. Results— The pediatric ICH score components include ICH volume >2% to 3.99% of total brain volume (TBV): 1 point; ICH volume ≥4% TBV: 2 points; acute hydrocephalus: 1 point; herniation: 1 point; and infratentorial location: 1 point. The score ranges from 0 to 5. At 3-month follow-up of 60 children, 10 were severely disabled or dead, 30 had moderate disability, and 20 had good recovery. A pediatric ICH score ≥1 predicted moderate disability or worse with a sensitivity of 75% (95% confidence interval [CI], 59% to 87%) and a specificity of 70% (95% CI, 46% to 88%). A pediatric ICH score ≥2 predicted severe disability or death with a sensitivity and specificity of 90% (95% CI, 55% to 99%) and 68% (95% CI, 53% to 80%), respectively. The area under the receiver operating characteristic curve for classifying outcome as severe disability or death was 0.88 (95% CI, 0.78–0.97). Conclusions— The pediatric ICH score is a simple clinical grading scale that may ultimately be used for risk stratification, clinical care, and research.

Background The purpose of this study was to define the incidence, imaging characteristics, natural history, and prognostic implication of corticospinal tract Wallerian degeneration ( CST ‐ WD ) in spontaneous intracerebral hemorrhage ( ICH ) using serial MR imaging. Methods and Results Consecutive ICH patients with supratentorial ICH prospectively underwent serial MRI s at 2, 7, 14, and 21 days. MRI s were analyzed by independent raters for the presence and topographical distribution of CST ‐ WD on diffusion‐weighted imaging ( DWI ). Baseline demographics, hematoma characteristics, ICH score, and admission National Institute of Health Stroke Score ( NIHSS ) were systematically recorded. Functional outcome at 3 months was assessed by the modified Rankin Scale ( mRS ) and the motor‐ NIHSS . Twenty‐seven patients underwent 93 MRI s; 88 of these were serially obtained in the first month. In 13 patients (48%), all with deep ICH , CST ‐ WD changes were observed after a median of 7 days (interquartile range, 7 to 8) as reduced diffusion on DWI and progressed rostrocaudally along the CST . CST ‐ WD changes evolved into T 2 ‐hyperintense areas after a median of 11 days (interquartile range, 6 to 14) and became atrophic on MRI s obtained after 3 months. In univariate analyses, the presence of CST ‐ WD was associated with poor functional outcome (ie, mRS 4 to 6; P =0.046) and worse motor‐ NIHSS (5 versus 1, P =0.001) at 3 months. Conclusions Wallerian degeneration along the CST is common in spontaneous supratentorial ICH , particularly in deep ICH . It can be detected 1 week after ICH on DWI and progresses rostrocaudally along the CST over time. The presence of CST ‐ WD is associated with poor motor and functional recovery after ICH .

Background Magnetic resonance diffusion-weighted imaging and perfusion-weighted imaging are able to identify ischaemic ‘footprints’ in transient ischaemic attack. Computed tomography perfusion (CTP) may be useful for patient triage and subsequent management. To date, less than 100 cases have been reported, and none have compared computed tomography perfusion to perfusion-weighted imaging (PWI). We sought to define the yield of computed tomography perfusion for the evaluation of transient ischaemic attack. Methods Consecutive patients with a discharge diagnosis of possible or definite transient ischaemic event who underwent computed tomography perfusion were included in this study. The presence of an ischaemic lesion was assessed on non-contrast computed tomography, automatically deconvolved CTPTMax (Time till the residue function reaches its maximum), and when available on diffusion-weighted imaging and PWITMax maps. Results Thirty-four patients were included and 17 underwent magnetic resonance imaging. Median delay between onset and computed tomography perfusion was 4.4 h (Interquartile range [IQR]: 1.9-9.6), and between computed tomography perfusion and magnetic resonance imaging was 11 h (Interquartile range: 3.8-22). Noncontrast computed tomography was negative in all cases, while CTPTMax identified an ischaemic lesion in 12/34 patients (35%). In the subgroup of patients with multimodal magnetic resonance imaging, an ischaemic lesion was found in six (35%) patients using CTPTMax versus nine (53%) on magnetic resonance imaging (five diffusion-weighted imaging, nine perfusion-weighted imaging). The additional yield of CTPTMax over computed tomography angiography was significant in the evaluation of transient ischaemic attack (12 vs. 3, McNemar, P = 0.004). Conclusions CTPTMax found an ischaemic lesion in one-third of acute transient ischaemic attack patients. Computed tomography perfusion may be an acceptable substitute when magnetic resonance imaging is unavailable or contraindicated, and has additional yield over computed tomography angiography. Further studies evaluating the outcome of patients with computed tomography perfusion lesions in transient ischaemic attack are justified at this time.

Perseverative behavior, manifest as re-cancelling or re-visiting targets, is distinct from spatial neglect. Perseveration is thought to reflect frontal or parietal lobe dysfunction, but the neuroanatomical correlates remain poorly defined and the interplay between neglect and perseveration is incompletely understood. We enrolled 87 consecutive patients with diffusion-weighted, perfusion-weighted imaging, and spatial neglect testing within 24 hours of right hemisphere ischemic stroke. The degrees of spatial neglect and perseveration were analyzed. Perseveration was apparent in 46% (40/87) of the patients; 28% (24/87) showed perseveration only; 18% (16/87) showed both perseveration and neglect; and 3% (3/87) showed neglect only. Perseverative behaviors occur in an inverted “U” shape: little neglect was associated with few perseverations; moderate neglect with high perseverations; and in severe neglect targets may not enter consciousness and perseverative responses decrease. Brodmann areas of dysfunction, and the caudate and putament, were assessed and volumetrically measured. In this study, the caudate and putamen were not associated with perseveration. After controlling for neglect, and volume of dysfunctional tissue, only Brodmann area 46 was associated with perseveration. Our results further support the notion that perseveration and neglect are distinct entities; while they often co-occur, acute dorsolateral prefrontal cortex ischemia is associated with perseveration specifically.

Background and Purpose— Diffusion-weighted imaging (DWI) is recommended for the evaluation of transient ischemic attack. Perfusion imaging can increase the yield of MRI in transient ischemic attack. We evaluated automated bolus perfusion (the time when the residue function reaches its maximum [TMax] and mean transit time [MTT]) and arterial spin labeling (ASL) sequences for the detection of ischemic lesions in patients with transient ischemic attack. Methods— We enrolled consecutive patients evaluated for suspicion of acute transient ischemic attack by multimodal MRI within 36 hours of symptom onset. Two independent raters assessed the presence and location of ischemic lesions blinded to the clinical presentation. The prevalence of ischemic lesions and the interrater agreement were1410 assessed. Results— From January 2010 to 2011, 93 patients were enrolled and 90 underwent perfusion imaging (69 bolus perfusion and 76 ASL). Overall, 25 of 93 patients (27%) were DWI-positive and 14 (15%) were perfusion-positive but DWI-negative (ASL n=9; TMax n=9; MTT n=2). MTT revealed an ischemic lesion in fewer patients than TMax (7 versus 20, P =0.004). Raters agreed on 89% of diffusion-weighted imaging cases, 89% of TMax, 87% o10f010 MTT, and 90% of ASL cases. The interrater agreement was good for DWI, TMax, and ASL (κ=0.73, 0.72, and 0.74, respectively) and fair for MTT (κ=0.43). Diffusion and/or perfusion were positive in 39 of 69 (57%) patients with a discharge diagnosis of possible ischemic event. Conclusions— Our results suggest that in patients referred for suspicion of transient ischemic attack, automated TMax is more sensitive than MTT, and both ASL and TMax increase the yield of MRI for the detection of ischemic lesions.

Background: Since transient ischemic attacks (TIAs) can predict future stroke, it is important to distinguish true vascular events from non-vascular etiologies. Arterial spin labeling (ASL) is a non-contrast magnetic resonance (MR) method that is sensitive to cerebral perfusion and arterial arrival delays. Due to its high sensitivity to minor perfusion alterations, we hypothesized that ASL abnormalities would be identified frequently in TIA patients, and could therefore help increase clinicians’ confidence in the diagnosis. Methods: We acquired diffusion-weighted imaging (DWI), intracranial MR angiography (MRA), and ASL in a prospective cohort of TIA patients. A subset of these patients also received bolus contrast perfusion-weighted imaging (PWI). Two neuroradiologists evaluated the images in a blinded fashion to determine the frequency of abnormalities on each imaging sequence. Kappa (ĸ) statistics were used to assess agreement, and the χ2 test was used to detect differences in the proportions of abnormal studies. Results: 76 patients met the inclusion criteria, 48 (63%) of whom received PWI. ASL was abnormal in 62%, a much higher frequency compared with DWI (24%) and intracranial MRA (13%). ASL significantly increased the MR imaging yield above the combined DWI and MRA yield (62 vs. 32%, p < 0.05). Arterial transit artifact in vascular borderzones was the most common ASL abnormality (present in 51%); other abnormalities included focal high or low ASL signal (11%). PWI was abnormal in 31% of patients, and in these, ASL was abnormal in 14 out of 15 cases (93%). In hemispheric TIA patients, both PWI and ASL findings were more common in the symptomatic hemisphere. Agreement between neuroradiologists regarding abnormal studies was good for ASL and PWI [ĸ = 0.69 (95% CI 0.53–0.86) and ĸ = 0.66 (95% CI 0.43–0.89), respectively]. Conclusion: In TIA patients, perfusion-related alterations on ASL were more frequently detected compared with PWI or intracranial MRA and were most frequently associated with the symptomatic hemisphere. Almost all cases with a PWI lesion also had an ASL lesion. These results suggest that ASL may aid in the workup and triage of TIA patients, particularly those who cannot undergo a contrast study.

Prognosis after stroke in children is difficult given the paucity of literature regarding motor and cognitive recovery. Spatial neglect has been described in children after stroke, yet little evidence exists to guide clinicians and parents regarding its resolution. Wallerian degeneration on magnetic resonance imaging (MRI) suggests poor recovery in neonates and adults. We report near complete resolution of spatial neglect in 4 weeks and significant improvement in hemiplegia in a 9-year-old boy with a right anterior cerebral artery and middle cerebral artery infarction, despite Wallerian degeneration apparent on diffusion-weighted imaging. Serial assessment of neglect documenting the rapid course of recovery is the unique feature of this case and may help serve as a guide to pediatricians and neurologists in assessment of young patients and counseling of parents. The lack of published outcome data suggests a need for larger studies about the recovery of spatial neglect and other cognitive symptoms following pediatric stroke.

Background and Purpose— Although intracerebral hemorrhage (ICH) volume and location are important predictors of outcome in adults, few data exist in children. Methods— A consecutive cohort of children, including full-term newborns to those younger than 18 years of age with nontraumatic, acute ICH and head CT available for analysis were studied. Clinical information was abstracted via chart review. Hemorrhage volume was expressed as percentage of total brain volume (TBV) with large hemorrhage defined as ≥4% of TBV. Hemorrhages were manually traced on each head CT slice and volumes were calculated by multiplying by slice thickness. Location was classified as supratentorial or infratentorial. Logistic regression was used to identify predictors of poor neurological outcome, defined as a Glasgow outcome scale ≤2 (death or persistent vegetative state). Results— Thirty children were included, median age 6 years. Median ICH volume was 20.4 cm 3 and median ICH size as a percentage of TBV was 1.9%. Only 4 of 22 children with ICH P =0.03). In multivariate analysis, hemorrhage ≥4% of TBV (OR, 22.5; 95% CI, 1.4–354; P =0.03) independently predicted poor outcome 30 days after ICH. In this small sample, infratentorial hemorrhage location and the presence of intraventricular hemorrhage did not predict poor outcome. Conclusions— ICH volume predicts neurological outcome at 30 days in children, with worst outcome when hemorrhage is ≥4% of TBV. Location and ICH etiology may also be important. These findings identify children with ICH who are candidates for aggressive management and may influence counseling regarding prognosis.

Lesion/deficit association studies of aphasia commonly focus on one brain region as primarily responsible for a particular language deficit. However, functional imaging and some lesion studies indicate that multiple brain regions are likely necessary for any language task. We tested 156 acute stroke patients on basic language tasks (naming and spoken and written word comprehension) and magnetic resonance diffusion and perfusion imaging to determine the relative contributions of various brain regions to each task. Multivariate linear regression analysis indicated that the error rate on each task was best predicted by dysfunction in several perisylvian regions, with both common and distinct regions for the 3 tasks.

Studies of the cognitive outcome after shunt insertion for treatment of Normal Pressure Hydrocephalus have reported widely mixed results. We prospectively studied performance of 60 patients with Normal Pressure Hydrocephalus on a comprehensive battery of neuropsychological tests before and after shunt surgery to determine which cognitive functions improve with shunt insertion. We also administered a subset of cognitive tests before and after temporary controlled drainage of cerebrospinal fluid to determine if change on this brief subset of tests after drainage could predict which patients would show cognitive improvement three to six months after shunt insertion. There was a significant improvement in learning, retention, and delayed recall of verbal memory three to six months after surgery (using paired t-tests). The majority (74%) of patients showed significant improvement (by at least one standard deviation) on at least one of the memory tests. Absence of improvement on verbal memory after temporary drainage of cerebrospinal fluid had a high negative predictive value for improvement on memory tests at 3–6 months after surgery (96%;p= 0.0005). Also, the magnitude of improvement from Baseline to Post-Drainage on few specific tests of learning and recall significantly predicted the magnitude of improvement after shunt surgery on the same tests (r2= 0.32–0.58;p= 0.04–0.001). Results indicate that testing before and after temporary drainage may be useful in predicting which patients are less likely to improve in memory with shunting.

Sites of lesions responsible for visual, tactile, and/or motor extinction have not been clearly identified. We sought to determine the frequency of extinction in various modalities immediately after acute ischemic stroke, the rate of co-occurrence of extinction across modalities, and areas of infarct and/or hypoperfusion associated with each modality of extinction. A total of 148 patients with right supratentorial stroke were studied. In Study 1, 88 patients without hemiplegia, hemianesthesia, or visual field cuts were tested within 24 hours of onset for visual, tactile, and motor extinction, and underwent magnetic resonance diffusion and perfusion imaging. Associations between modality of extinction and areas of neural dysfunction (hypoperfusion/infarct) were identified. Of the 88 patients, 19 had only tactile extinction, 8 had only visual extinction, 12 had only motor extinction, 14 had extinction in two or more modalities, and 35 had no extinction. Tactile extinction was associated with neural dysfunction in the inferior parietal lobule; visual extinction was associated with dysfunction in the visual association cortex; and motor extinction was associated with neural dysfunction in the superior temporal gyrus. In Study 2, data from 60 patients who were excluded from Study 1 because of motor deficits were analyzed in the same way to determine whether frontal lesions contributed to visual or tactile extinction. Results again demonstrated that tactile extinction is associated with inferior parietal dysfunction, and visual extinction is associated with dysfunction of the visual association cortex. Potential accounts of the results, based on the “hemisphere rivalry” model of extinction and the limited attentional capacity model, are considered.

Background. Abnormalities in diffusion-weighted (DWI) and perfusion-weighted (PWI) magnetic resonance imaging (MRI) are thought to reflect the presence of brain tissue at risk for ischemic stroke. Many patients with acute ischemic stroke have a mismatch pattern in which the PWI volume is larger than the DWI lesion. This mismatch typically resolves over 24-48 hours. Little is known about the presence of DWI-PWI mismatch in later stages of stroke. Methods. This is a retrospective study of 122 patients admitted with a diagnosis of acute ischemic stroke who had DWI and PWI abnormalities on studies performed within 7 days of onset of symptoms. Patients were divided into two groups: those with MRI performed

The study by Numata et al. is of interest since it isbased on a large sample (n=86) of patients, focuses onterm-born patients and on one CP type (BSCP), andincludes information on severity of motor impairment andcognitive function, as well as epilepsy. However, it alsohighlights a number of issues that are common in studieson the pathophysiology of CP and associations betweenpossible underlying brain lesions, severity of motor impair-ment, and cognitive function – all of which often makeinterpretation of findings and inferring conclusions diffi-cult. In this study there was a large range with regards toage at diagnosis of CP, including patients who had beengiven the diagnosis of CP at an age (as young as 6mo)where one can still expect transitory neurological signs in anumber of children, making a definite diagnosis of CP dif-ficult. The study mainly used information obtained retro-spectively from medical records with regards to type ofCP, severity of motor impairment, and other relevant clini-cal variables. Some patients were scanned at an age asyoung as 10 months, when myelination is still not com-plete in typical development and which can make diagnosisof a non-progressive brain lesion difficult. In the light ofthe high proportion of normal MRI findings seen in thisstudy, this emphasizes the importance of adhering toguidelines such as issued by the Surveillance of CerebralPalsy in Europe Network (e.g. with regards to timing ofCP diagnosis).The study by Numata et al. also highlights that it isimportant to use advanced imaging techniques when inves-tigating neuroanatomical correlates of CP, in particular inthose cases where visual inspection of conventional MRIshows no abnormalities. Diffusion MRI is one suchmethod that increases sensitivity in detecting abnormalities.For example, Son et al.

Spatial processing was assessed following implantation of subdural electrodes in the nondominant hemisphere with electrocortical stimulation mapping (ESM) in two patients before epilepsy surgery. The first patient had mild hemispatial neglect/extinction during ESM of posterior temporal and inferior parietal areas. These areas were resected, and the patient had postoperative deficits that were similar to those occurring with ESM. The second patient was found to have marked hemispatial neglect during stimulation of parietal areas. These areas were not resected, and the patient had no neglect following surgery. These results suggest that ESM can help predict spatial processing deficits associated with cortical resection, and may help prevent postoperative impairments following resection in right parietal or temporal regions.