NONVERBAL VISUAL-ATTENTION, BUT NOT RECOGNITION MEMORY OR LEARNING, PROCESSES ARE IMPAIRED IN MOTOR-NEURON DISEASE

Pathology outside the motor system is being increasingly recognised in motor neurone disease (MND) and up to 3% of patients may have overt d ementia of frontal lobe type; it is not clear whether milder cognitive disturbance is a more frequent feature of the disease. Standard neuro psychological testing can be difficult in MND and we therefore used th e microcomputer-controlled Cambridge Neuropsychological Test Automated Battery (CANTAB((C))), which allows accurate assessment in the presen ce of motor and bulbar dysfunction. The results of subtests evaluating nonverbal visual attention, recognition memory and learning from a la rge (n = 50) group of patients with MND compared to normal (n = 27) an d neurological disease (n = 23) control groups are presented in this r eport. The MND group showed significant impairment in a focal attentio n (visual search) task, but no deficits in memory or learning. Inspect ion of the visual search data showed that up to a quarter of the MND p atients scored two or more standard deviations below the mean control score. It is suggested that this reflects pathology in fronto-striatal circuitry.