Neurobehavioral effects of intrathecal somatostatinergic treatment in subhuman primates.

We infused somatostatin and its long-acting analogue (SMS 201-995) into the intracranial subarachnoid space of eight monkeys. Chronic infusions of SMS 201-995 produced marked neurotoxic effects characterized by truncal ataxia, dysmetria, and severe bradykinesia, with normal level of consciousness. Subcutaneous injection of apomorphine, a dopaminergic agonist, promptly reversed these effects. Further studies are required before intrathecal somatostatin replacement therapy can be offered to patients with Alzheimer9s disease.