The Japanese journal of neuropsychology

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ArticleTitle	Clinical studies and neuroimaging in individual subjects
Language	J
AuthorList	Kazuyo Tanji
Affiliation	Department of Clinical Neuroscience, Yamagata University Graduate School of Medicine
Publication	Japanese Journal of Neuropsychology: 31 (1), 26-33, 2015
Received
Accepted
Abstract	Ever since 19^th-century discoveries of language areas, much scientific knowledge regarding topology of neuropsychological function has been accumulated. However, it is still not easy in everyday clinical practice to know precisely how a lesion causes a clinical symptom because lesions usually span across multiple structures, and because of differences in individual lesions as well as underlying anatomy. Studies on patients with lesions in circumscribed areas, as well as knowledge obtained through functional neuroimaging is crucial in advancing understanding of functional localization. In the first part of this talk, a case with lesion restricted to the precentral gyrus and the insula, which accompanied pure anarthria with characteristic phoneme sequencing errors was reported. The peculiar symptom of the case together with a review of the literature suggested that the variability of articulatory disturbance is the rule rather than the exception even in cases with lesions restricted to the precentral gyrus. In the latter part of the talk, a case who underwent awake craniotomy during which electrocorticographic recordings from the precentral gyrus were made while the patient performed a verb generation task. Other than well-known motor activities in the precentral gyrus, auditory response was observed, which was consistent with results recent functional magnetic resonance imaging (fMRI) studies have found that the ventral part of the precentral gyrus is activated in response to linguistic auditory stimuli. The distribution of the auditory response within the precentral gyrus was scattered into at least two clusters, and completely different patterns of response were observed in adjacent electrodes only 5 mm apart. The two studies points to the same conclusion that even the precentral gyrus, which tends to be regarded as a rather simple structure, has a complex functional distribution. These findings from individual case studies suggest that it is not easy to make generalizations regarding mind-brain interactions based only on group activation maps.
Keywords	premotor area, pure anarthria, precentral gyrus, electrocorticogram, apraxia of speech