Authors :
Paula Marques, MD, CSCN (EEG) – Adult Genetic Epilepsy (AGE) Program, Toronto Western Hospital, University Health Network
Armeen Atif, BSc – Adult Genetic Epilepsy (AGE) Program, Toronto Western Hospital, University Health Network
Victor Lira, MD, CSCN (EEG) – University of Toronto, Toronto Western Hospital, University Health Network
Presenting Author: Quratulain Zulfiqar Ali, MD – Adult Genetic Epilepsy (AGE) Program, Toronto Western Hospital, University Health Network/University of Toronto
Danielle Andrade, MD, MSc, CSCN (EEG) – Adult Genetic Epilepsy (AGE) Program, University of Toronto, Toronto Western Hospital, University Health Network
Rationale:
- Cortical myoclonus originates at cerebral cortex, predominantly occurring on voluntary movements, such as gait and is triggered by stimuli including touch.
- Acetazolamide (ACZ) is an inhibitor of the carbonic anhydrase protein which ultimately results in a low intracellular pH, causing acidification.
- Current evidence shows that a seizure focus tends to be alkaline, thus the change in pH induced by ACZ is postulated to explain some of the anti-seizure effects.
To date, very few cases have described the use of ACZ in myoclonus. In this work, we present 2 patients with progressive myoclonic epilepsy (PME) with an improvement in their myoclonus with ACZ, despite poor response to other antiseizure medications (ASMs).
Methods: Chart review of 2 patients was performed. Literature review was conducted on myoclonus and ACZ using Pubmed.
Results:
Case 1: 22-year-old female, diagnosed with PME secondary to a
KCNC1 variant. Her symptoms started at 10 years of age with bilateral tonic clonic seizures (BTCS). She later developed progressive ataxia and myoclonus, involving face and limbs, which worsened with stimulus and menses. Perampanel, Clonazepam and Levetiracetam was started, however myoclonus was still limiting. At the age of 19, ACZ 250 mg BID was started for 2 weeks around her menses which led to significant improvement of myoclonus, resulting in better ambulation, balance and speech. These improvements were sustained 2.5 years later.
Case 2: 67-year-old male, previous history of diabetes, sleep apnea and hypothyroidism presented with BTCS at the age of 53 along with cortical myoclonus
(Figure 2), dementia and ataxia, leading to diagnosis of PME with an
IRF2BPL variant. His myoclonus would worsen in the morning or with anxiety, ranging from 4 to 10 per hour, compromising his ability to perform independent activities of daily living and requiring a walker on a regular basis. Improvement of myoclonus occurred with ACZ 250 mg BID biweekly which was sustained after 2 years, although balance and cognition continued to deteriorate as part of his condition.
Conclusions: Previous literature outlines 4 cases of action myoclonus that responded to ACZ. Our study adds 2 patients to the current literature. Hence, we conclude that the use of ACZ should be considered in the treatment of myoclonus, especially in cases with cortical involvement and hormonal fluctuations.
Funding: None