Long-term Assessment of Aphasic Symptoms in Patients with Lesions in the Nucleus Lentiformis and Thalamus

Abstract

    The presence of thalamic and putaminal aphasia was proposed some time ago with the putative foci in the thalamus and the basal ganglia. However, a general consensus has not been reached in designating the thalamus and putamen as the actual foci responsible for this clinical entity. In the present study, we observed aphasic symptoms in 55 right-handed patients with lesions in the left hemisphere, with recognized major foci in the nucleus lentiformis or thalamus detected on x-ray and MRI-CT. From this study, we arrived at the following conclusions:
    1. Patients with foci localized in the nucleus lentiformis did not exhibit persistent aphasic symptoms. On the other hand, most patients with the foci spreading to the arcus fasciculus, subcortical region, or cerebral cortex or with dilatation of the lateral ventricle, suffered from persistent aphasic symptoms.
These findings appeared to negate the possibility of the nucleus lentiformis acting as the putative focus.
    2. On some occasions patients with thalamic lesions exhibited very mild language disorders. However, these differed in nature from aphasic symptoms. It is probable that the former can be explained by a disturbance of vigilance.
    3. It might be necessary to re-examine terminology such as putaminal and thalamic aphasias.