Abstract #1151

Blain C, Leigh P, Stanton B, Simmons A, Williams V

There is evidence of altered cortical activation during motor tasks in patients with Amyotrophic Lateral Sclerosis (ALS), but previous studies have failed to adequately control for weakness. 16 ALS patients, 9 patients with lower motor neurone syndromes (matched for upper limb weakness) and 17 controls performed a block design paradigm contrasting freely selected right hand movements against rest. ALS patients showed increased activation around the sensorimotor cortex, but reduced activation in pre-frontal regions compared to controls and LMN patients. We conclude that these changes are not simply an artefact of weakness, but relate specifically to upper motor neurone pathology in ALS.