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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.

Objective To test whether lesion site patterns in patients with chronic, severe aphasia who have no meaningful spontaneous speech are predictive of outcome following treatment with a nonverbal, icon-based computer-assisted visual communication (C-ViC) program. Design Retrospective study in which computed tomographic scans performed 3 months after onset of stroke and aphasia test scores obtained before C-ViC therapy were reviewed for patients after receiving C-ViC treatment. Setting A neurology department and speech pathology service of a Department of Veterans Affairs medical center and a university aphasia research center. Patients Seventeen patients with stroke and severe aphasia who began treatment with C-ViC from 3 months to 10 years after onset of stroke. Main Outcome Measure Level of ability to use C-ViC on a personal computer to communicate. Results All patients with bilateral lesions failed to learn C-ViC. For patients with unilateral left hemisphere lesion sites, statistical analyses accurately discriminated between those who could initiate communication with C-ViC from those who were only able to answer directed questions. The critical lesion areas involved temporal lobe structures (Wernicke cortical area and the subcortical temporal isthmus), supraventricular frontal lobe structures (supplementary motor area or cingulate gyrus 24), and the subcortical medial subcallosal fasciculus, deep to the Broca area. Specific lesion sites were also identified for appropriate candidacy for C-ViC. Conclusions Lesion site patterns on computed tomographic scans are helpful to define candidacy for C-ViC training, and to predict outcome level. A practical method is presented for clinical application of these lesion site results in combination with aphasia test scores.

Apractic agraphia is an impairment in writing in which the actual orthographic production of letters and words is abnormal despite normal sensorimotor function, visual feedback, and word and letter knowledge. We report one case and review the limited clinicoanatomical literature. Analysis of available cases supports the hypothesis that apractic agraphia is one of several related clinical disorders that are due to the loss of spatially and kinesthetically modulated movements. It is produced by lesions in the superior parietal lobule, usually in the hemisphere dominant for language.

• Two patients with transcortical motor aphasia are described. Both had infarcts in the distribution of the left anterior cerebral artery confirmed by computerized tomography (CT). The distinctive language abnormality, unusual EEG pattern, and nuclide and CT scan abnormalities all allow ready diagnosis of the syndrome of infarction in this distribution. The mechanism of the language disturbance is reviewed and implications for treatment and prognosis are discussed.

• Six patients had ischemic infarcts in the paramedian thalamic, subthalamic, and mesencephalic areas. In addition to ocular motility problems, ataxia, dysmetria, and mild pyramidal signs, there were consistent behavioral observations and neuropsychological findings. All of the patients had initial deficits in arousal, and gradually improved to normal wakefulness. When awake, all of the patients had impaired attention, mental control, and slowed verbal and motor responsiveness. They were apathetic, poorly motivated, and affect was flat or occasionally labile. All of the patients had a memory disorder characterized by anterograde and retrograde loss. One patient had significant language impairment. These deficits persisted in all but one patient who had a predominantly mesencephalic lesion. We believe the cluster of findings in these patients constitutes a characteristic syndrome of dementia related to paramedian mesencephalic and diencephalic infarcts. This syndrome bears close resemblance to that associated with some subcortical degenerative disorders such as progressive supranuclear palsy. In cases of paramedian mesencephalic and diencephalic infarcts, however, computed tomography and magnetic resonance imaging can delineate clinicoanatomic relationships that account for specific constituents of the syndrome.

• We examined four patients with transcortical sensory aphasia and eight with milder language disturbances but with similar thalamic and/or temporo-occipital lesions. Specific attention was paid to differentiation of the computed tomographic lesion site of the milder cases from the transcortical sensory aphasia cases. The critical lesion for transcortical sensory aphasia in these patients involved pathways in the posterior periventricular white matter adjacent to the posterior temporal isthmus, pathways that are probably converging on the inferolateral temporo-occipital cortex. Analysis of the language function of these patients, of the influence of sensory modalities on language function, and of the interaction between semantic memory and semantic lexical functions suggests the existence of a specific brain system for semantic functions. This semantic system has a particular distributed anatomy. We propose that damage to this system may have a variety of clinical manifestations in language and in memory, depending on the exact lesion configuration.

• Nine cases of subcortical aphasia with capsular/putaminal (C/P) lesion sites demonstrated on computed tomographic (CT) scans were studied. Eight cases were occlusive-vascular in etiology and one was hemorrhagic. Three subcortical aphasia syndromes and three C/P lesion site patterns were observed. Patients with C/P lesion sites with anterior-superior white-matter lesion extension had good comprehension, grammatical, but slow, dysarthric speech, and lasting right hemiplegia. Patients with C/P lesion sites with posterior white-matter lesion extension across the auditory radiations in the temporal isthmus had poor comprehension, fluent Wernicke-type speech, and lasting right hemiplegia. Patients with C/P lesion sites with both anterior-superior and posterior extension were globally aphasic and had lasting right hemiplegia. Although these cases of C/P subcortical aphasia shared certain well-known features of Broca's and Wernicke's cortical aphasia syndromes, they did not completely resemble cases of either Broca's, Wernicke's, global, or thalamic aphasia in neurologic findings, CT scan lesion sites, or language behavior. Further study of the subcortical aphasias associated with these C/P lesion sites seems to be warranted.

• Hospital records of 53 children and adolescents, aged 18 years or less, with closed head injury were reviewed for information on long-term outcome. Computed tomographic scans were used to divide the patients into clinicopathologic groups. Within these groups, duration of coma was the major index of severity. Outcome was assessed using the Glasgow Outcome Scale and by evaluating social behavior, school performance, and vocational functioning. Patients with diffuse injury plus focal lesions fared worse than those with diffuse injury only. Coma lasting more than one month led to a poorer outcome in both groups. Many individuals had limiting emotional disturbances, which may have resulted from disruption of frontal systems modulating arousal and social behavior.

• Solitary plasmacytoma Invaded the petrous bone of a patient, and produced multiple cranial neuropathies. To our knowledge, this tumor has not previously been reported to cause this syndrome.

• We present a case of progressive bulbar paresis in a 2-year-old child, with appropriate autopsy findings. A review of previously reported cases and a comparison with more extensive literature in Werdnig-Hoffmann disease suggest that Fazio-Londe disease is not unique, but belongs in the spectrum of progressive lower motor neuron disease.

• A syndrome of dysarthria following the appearance of small left frontal-lobe lesions has been recognized for many years but identified by numerous labels. Varied terminology has led to confusion in the literature and inadequate recognition of this syndrome as a distinctive clinical entity. We gathered clinical and anatomic (computed tomographic) data on four patients with this dysarthric syndrome and reviewed cases from the literature that contained sufficient clinical and anatomic data for comparison. These patients had a distinctive syndrome of dysarthria without aphasia, caused by small lesions of the motor system for articulation: pars opercularis, inferior prerolandic gyrus, or white matter deep to those regions. This syndrome should be distinguished from Broca's aphasia, Broca's area aphasia, transcortical aphasia, and subcortical aphasia. Aphemia is not mild Broca's aphasia; it is severe dysarthria, at times in the setting of transient Broca's aphasia.

• In an attempt to establish a method for determination of mental competence, a two-part investigation was undertaken. First, a model for mental competence was devised that would be applicable across a broad range of neurologic disorders; this model was based on a patient's ability to make complex decisions. Second, a retrospective analysis of competence in 92 inpatients on a neurobehavioral service was carried out. The model was useful way to view competence, at least in this population. Competence could be classified as operational, limited to a single cognitive domain, or as general, cutting across all domains in a way for which no compensation could be devised. The results suggest that a model of competence based on analysis of individual congnitive operations will provide a sound clinical approach to a common problem that is presently not well characterized.