Abstracts

RATIONALE: PME 1 is a rare autosomal recessive genetic disorder associated with continual myoclonia, generalized tonic-clonic seizures (GTC),ataxia and mild dementia. Certain antiepileptic drugs (AEDs) are partially effective in controlling the myoclonia and GTC. However symptoms remain a problem.VNSTM is a recognized treatment for patients with intractable epilepsy.We investigated whether VNSTM would improve the symptoms of PME 1, especially myoclonia, GTC and ataxia. METHODS: Two females,aged 27 and 29 with PME 1 since the age of 12 were implanted with VNSTM according to a standard procedure.Both were treated with AEDs:zonisamide, clonazepam and valproic acid and one of the patients was even taking acetylcysteine. Changes in myoclonia and ataxia were monitored by objective criteria such as gait, holding cup, writing and tests of finger coordination. RESULTS: The 3-month results are available from the first patient at the time of this abstract. VNSTM parameters were 0.75 mA. 30 Hz, 500 msec, 30 seconds on and 5 minutes off. GTCs were reduced by 50% from 4 to 2 per month. Ataxia improved by >50% as did the myoclonia. Her speech normalized. She could hold a cup of hot coffee without spilling, drawing skills and fine coordination were also improved. Walking changed from a forward stumbling ataxic gait to an ordinary upright posture and normal steps. No negative side effects other than those previously reported for VNSTM were apparent. CONCLUSIONS: PME 1 is a very incapacitating disorder where AEDs are only partially effective. These preliminary data are the first evidence that VNSTM may further reduce the multiple symptoms and signs of this serious disorder.