P.049 Acetazolamide use for myoclonus: case report of 2 patients with progressive myoclonic epilepsy and literature review

Background: Cortical myoclonus originates at cerebral cortex, predominantly occurring on voluntary movements. Few case reports described usage of Acetazolamide (ACZ) for myoclonus. Methods: Chart review of 2 patients was performed. Literature review was conducted on myoclonus and ACZ using Pubmed. Results: 22-year-old female was diagnosed with Progressive Myoclonic Epilepsy (PME) secondary to a KCNC1 mutation. Her symptoms started at 10 years old with bilateral tonic clonic seizures (BTCS), later developing progressive ataxia and myoclonus, involving face and limbs, which worsened with stimulus and menses. Medications included Perampanel, Clonazepam and Levetiracetam, however myoclonus was still limiting. At the age of 19, ACZ 250 mg BID was started for 2 weeks around her menses. Follow up revealed significant improvement of myoclonus, resulting in better ambulation, balance and speech, sustained 2.5 years after. 67-year-old male presented BTCS at the age of 53 along with cortical myoclonus, dementia and ataxia, leading to diagnosis of PME with a mutation on IRF2BPL. Improvement of myoclonus occurred with ACZ 250 mg BID biweekly, although balance and cognition still deteriorated. Conclusions: Previous literature outlines 4 cases of action myoclonus that responded to ACZ. We believe that ACZ should be considered to treat myoclonus, especially in cases with cortical involvement and hormonal fluctuations.