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Stroke-related translational research is multifaceted. Herein, we highlight genome-wide association studies and genetic studies of cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy, COL4A1 mutations, and cerebral cavernous malformations; advances in molecular biology and biomarkers; newer brain imaging research; and recovery from stroke emphasizing cell-based and other rehabilitative modalities.

Hemispatial neglect can occur as the aftermath to a stroke. The condition gets its name from the apparent neglect by the patient of half the world, most often the left side of the patient. In some cases, the neglect may extend to half the patient's own body. The condition does not seem to result from a loss of sensation. However, theories vary on whether hemispatial neglect results from a deficit of attention, a breakdown in communication between the cerebral hemispheres, or a defect in the representation within the brain of the visual space surrounding the patient. Experimental data do indicate, however, that the patient's ability to respond to events in the neglected space vary depending upon the details of the requirements of the individual task. The performance of patients on tests can be altered by either useful or distracting cues, and it seems that patients perform better when simple sensory stimuli are presented in the neglected space than when the stimuli are complex. A study was conducted to evaluate the relation between the complexity of stimuli and the performance of a spatial task by nine patients with right hemisphere strokes and left hemispatial neglect. The task consisted of cancelling out the letter ''A'' wherever it appeared on a large sheet of paper. In the series of tests, the locations of the letters A on the sheet never changed, but the surrounding distractor letters changed. The patients could mark each A when no distractors were present, regardless of whether the letter occurred on the left or right side. However, with more distractor letters, it was more difficult it was to find the A's on the left side of the sheet. Although it was possible in some cases for the patient to identify more A's on the normally neglected left side than on the right where the distractors were, overall performance on the left was diminished when the distractors were present only on the right, the side which was not neglected. These results are interpreted to suggest that the attentional abilities of the neglect patient's left hemisphere are limited. If few demands are placed upon it, it can perform well even in the left visual space. However, when the demands on attention are increased, performance deteriorates. (Consumer Summary produced by Reliance Medical Information, Inc.)

Much of what is known about the function of different regions of the human brain has been learned from pathological conditions. The caudate nucleus, a region of the basal ganglia which is located below the brain's cortex, is involved in involuntary movement. Although the caudate nucleus is affected in diseases like Huntington's disease, attributing specific symptoms to the caudate nucleus is difficult because most degenerative diseases affect more than one brain area. In contrast, strokes often affect particular areas of the brain with some precision and leave other regions unaffected, and consequently provide a better opportunity for the study of function. A study of 18 patients with stroke-related focal lesions in the caudate area were studied, and a range of motor, behavioral, and cognitive disturbances were observed. Five of the patients had no motor symptoms, and 11 had only slight symptoms. Two patients had a moderately severe muscular weakness. Eleven patients had speech difficulties due to muscle weakness; six of these patients had right-side caudate lesions and five had left-side lesions. Four patients did not seem to have any noticeable behavioral or cognitive disturbances. Ten of the 18 patients had a problem consisting of profound disinterest, decreased spontaneous activity, prolonged latency in response to questions of stimuli, and decreased ability to persist in a task. This state of 'no will' has been termed 'abulia'. Seven patients were confused, restless, or hyperactive during their acute stroke; in three patients these states alternated with abulia. Three patients with right-side lesions ignored objects on their left-hand side. Other symptoms observed in some of the patients included mumbling, echolalia, and poor drawing and copying. The small number of patients reviewed cannot lead to a definitive discussion about the function of the caudate nucleus, but it is clear that the important motor functions previously attributed to the caudate are only a portion of the total picture. (Consumer Summary produced by Reliance Medical Information, Inc.)