Spinal segmental myoclonus following spinal surgery.

A 44-year-old male was admitted with L5/S1 spondylodiscitis complicated by a posterior epidural abscess that was compressing the thecal sac with severe narrowing of the canal and compression of the cauda equine. He underwent computed tomography (CT) guided drainage followed by L5/S1 decompression laminectomy and was started on a 6-week course of intravenous antibiotics with good response. He remained well and afebrile with inflammatory markers showing improvement. During this period, he developed intermittent myoclonic movements of right lower limb with severe pain over the back radiating to the gluteal region which hindered his rehabilitation potential. He was diagnosed with spinal segmental myoclonus based on clinical findings and history of recent spinal surgery. He was successfully treated with a course of clonazepam and continues to make functional improvements during his rehabilitation program.

Propriospinal myoclonus: diagnostic value of polymyography and video polysomnography.

Propriospinal myoclonus is a hyperkinetic movement disorder characterized by painless jerks of the axial muscles, mainly in the trunk and hips. A 53-year-old woman was referred to the Sleep Unit with trunk flexion movements in the supine position during the wake-sleep transition and during sleep, with premonitory sensation. We performed 2 video polysomnographic recordings. In the first video polysomnogram, the recording showed jerks of the trunk and abdomen that appeared when the posterior dominant alpha rhythm disappeared; during these jerks the patient stayed at stage 1 or stage 2 of non-rapid eye movement sleep. The second video polysomnogram included several electromyogram electrodes located at the masseter, deltoid, rectus abdominis (T9-T0 level), vastus lateralis, and tibialis anterior muscles. This polysomnogram revealed 123 repetitive arrhythmic jerks with variable duration, usually lasting 500-1,900 ms each (906 ± 0.4 ms). In our patient, propriospinal myoclonus was detected up to stage 2 of non-rapid eye movement sleep and even at rapid eye movement sleep. CITATION: Ramos RW, Viñas LL, Martín ER, Cárdenas CL, Pereda AF, Manzanares LL. Propriospinal myoclonus: diagnostic value of polymyography and video polysomnography. J Clin Sleep Med. 2023;19(5):995-998.