Objective: Describe DBS for 2 patients with severe post-hypoxic myoclonus.

Background: Limited prior reports have shown improvement of PHM after DBS. We describe 2 recent cases of severe PHM, both of which demonstrated improved myoclonus after globus pallidus internus (GPi) DBS.

Method: Description of clinical cases and therapeutic approach

Results: Case 1: 25 year old man with PHM was referred for DBS. At age 23, he suffered cardiopulmonary arrest secondary to massive pulmonary emboli. Following resuscitation, he was noted to have severe myoclonus, which persisted despite rehabilitation and medications, including valproic acid, levetiracetam, clonazepam and zonisamide. Trial of sodium oxybate was not tolerated. He underwent bilateral GPi DBS, and experienced a temporary microlesional benefit. Improvement of myoclonus started 5 months after implantation. He experienced improvement in function, including using phone, turning in bed, standing. Benefit was sustained for 4 months, after which clinical course worsened when patient underwent baclofen pump placement at an outside facility, and had social stressors leading to placement in a nursing home. Most recent DBS settings: left – contact 3+2-1-, amp3.5, pw250, f32, right – contact 10+11-, amp3.5, pw300, f32. Case 2: 57 year old man with PMH was referred for DBS. At age 54, he underwent anterior cervical decompression surgery, complicated by thyroidal artery hemorrhage and cardiopulmonary arrest. He noticed myoclonus upon regaining consciousness. Myoclonus caused significant functional impairment with daily activities despite rehabilitation and medications, including sodium oxybate, lorazepam, valproic acid, levetiracetam, and zonisamide. He underwent bilateral GPi DBS with notable improvement after 1 month, and continued benefit after 2 years. He regained the ability to perform activities of daily living independently, such as eating, drinking, and walking. Most recent DBS settings: left – contacts 3+2-, amp3.5, pw100, f130, right – contacts 12+11-, amp3.5, pw100, f130.

Conclusion: Post-hypoxic myoclonus is a rare disorder in patients who have survived cardiopulmonary arrest. In some cases, the severity of myoclonus significantly impacts function and quality of life. Improvement of myoclonus following pallidal DBS has been reported in a limited number of cases. We report here 2 additional cases, in which patients experienced significant functional improvement of PHM following pallidal DBS.

References: 1. Hallett M. Physiology of human posthypoxic myoclonus. Mov Disord. 2000;15 Suppl 1:8-13. doi:10.1002/mds.870150703
2. Riboldi GM, Frucht SJ. Increasing Evidence for the Use of Sodium Oxybate in Multi-Drug-Resistant Lance-Adams Syndrome. Tremor Other Hyperkinet Mov (N Y). 2019;9:10.7916/d8-rnsh-c024. Published 2019 Jun 17. doi:10.7916/d8-rnsh-c024
3. Ramdhani RA, Frucht SJ, Kopell BH. Improvement of Post-hypoxic Myoclonus with Bilateral Pallidal Deep Brain Stimulation: A Case Report and Review of the Literature. Tremor Other Hyperkinet Mov (N Y). 2017;7:461. Published 2017 May 19. doi:10.7916/D8NZ8DXP
4. Kim MJ, Park SH, Heo K, Chang JW, Kim JI, Chang WS. Functional Neural Changes after Low-Frequency Bilateral Globus Pallidus Internus Deep Brain Stimulation for Post-Hypoxic Cortical Myoclonus: Voxel-Based Subtraction Analysis of Serial Positron Emission. Brain Sci. 2020 Oct 13;10(10):730. doi: 10.3390/brainsci10100730.
5. Gao F, Ostrem JL, Wang DD. Treatment of Post-Hypoxic Myoclonus using Pallidal Deep Brain Stimulation Placed Using Interventional MRI Methods. Tremor Other Hyperkinet Mov (N Y). 2020 Oct 13;10:42. doi: 10.5334/tohm.544.
6. Asahi T, Kashiwazaki D, Dougu N, Oyama G, Takashima S, Tanaka K, Kuroda S. Alleviation of myoclonus after bilateral pallidal deep brain stimulation for Lance-Adams syndrome. J Neurol. 2015 Jun;262(6):1581-3. doi: 10.1007/s00415-015-7748-x.
7. Yamada K, Sakurama T, Soyama N, Kuratsu J. Gpi pallidal stimulation for Lance-Adams syndrome. Neurology. 2011 Apr 5;76(14):1270-2. doi: 10.1212/WNL.0b013e31821482f4.

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MDS Abstracts - https://www.mdsabstracts.org/abstract/pallidal-dbs-improves-myoclonus-in-2-patients-with-post-hypoxic-myoclonus/