CT scan Cerebral Hemispheric Asymmetry Measurements in Stroke Cases with Global Aphasia: Atypical Asymmetries Associated with Improved Recovery

Abstract

This study was undertaken in order to examine the relationship between CT scan hemispheric asymmetries and recovery in aphasia. The study had two parts. In Part I, hemispheric asymmetries were measured on the CT scans of 60 right-handed male non-aphasic (non-neurological) controls and 89 right-handed male aphasics, using a modification of LeMay's (1977) techniques. Both the non-aphasic control and aphasic data were in agreement with that of LeMay for frontal width, occipital width and occipital length. In Part II, the degree of CT scan hemispheric asymmetry was quantified for 14 right-handed male global aphasics, in whom differences in degree of language recovery were observed in the months following stroke. Atypical occipital asymmetries were significantly associated with certain aspects of language recovery (naming, single-word comprehension and single-word repetition). The authors postulate that increased capacity for right hemisphere contribution to language function might in part explain recovery in the cases exhibiting atypical occipital CT asymmetries.

Brainprints: Computer-Generated Two-Dimensional Maps of the Human Cerebral Cortex in vivo

“…That various brain asymmetries have been correlated with handedness (LeMay 1976(LeMay , 1977LeMay and Kid0 1978;Bear et al 1986;Kertesz et al 19861, sex (Wada et al 1975;Bear et al 19861, recovery from aphasia (Pieniadz et al 1983) and hemiplegia (Scheckman et al 1983) following stroke, developmental dyslexia (Hier et al 1978b), schizophrenia (Luchins et al 19791, and autism (Hier et al 1978a) argues in favor of the basic premise that size asymmetries are behaviorally relevant. Angular, areal, and topological distortion are discussed in detail in Appendix 11.…”

Recovery from Aphasia and Neglect

“…However, the evidence for such claims is rather limited [24,25]. Atypical skull asymmetries (large left frontal or right occipital torque) were associated with a better prognosis in one study [26], but this was not confirmed by subsequent investigations [27,28].…”

Cerebral blood flow in subcortical global aphasia. Perisylvian cortical hypoperfusion as a crucial role.

“…From a morphological point of view, hemisphere asymmetry has been described to have an effect on recovery from aphasia. 17 From a functional point of view, variations in plastic changes after damage to the brain should be regarded as a possible mechanism. The early occurrence and persistence of compensatory functions have been verified in animal studies.…”