A POSITRON EMISSION TOMOGRAPHY STUDY OF FRONTAL-LOBE FUNCTION (VERBALFLUENCY) IN AMYOTROPHIC-LATERAL-SCLEROSIS

Positron emission tomography (PET) was used to investigate the locatio n of cerebral cortical and subcortical abnormalities in non-demented p atients with amyotrophic lateral sclerosis (ALS). Involvement of the f rontal lobes was investigated with a task of executive frontal lobe fu nction (verbal fluency/word generation), using a PET activation paradi gm. Two groups of ALS patients defined by the presence or absence of c ognitive impairment were tested. ALS patients who had cognitive impair ments showed a region of cortical and subcortical dysfunction which ex tended across a wide area of the frontal lobes, and included the insul ar cortex and thalamic nuclear complex. These findings support the not ion that extra-motor involvement is relatively common in ALS and broad ens concepts of selective vulnerability in ALS.