Video 1
Myoclonus at rest and with action. Cortical and subcortical myoclonus affecting the patient’s speech and limb movements.
Video 2
Myoclonic volley. Episode of myoclonic volley with frequent generalized myoclonus at rest and with action.
Video 3
Myoclonus when standing. Negative myoclonus observed in the patient’s legs when standing.
Figure 1
Bilateral DBS electrode position. Preoperative magnetic resonance imaging quantitative susceptibility mapping of coronal sequences showing the co-registered postoperative computed tomography location of the centroid (red dot) of the left (A) and right (B) electrodes in the globus pallidus internus.
Video 4
6 months after with Bilateral GPi-DBS. Reduction in myoclonus with pallidal deep brain stimulation. The patient is able to drink from a water bottle, push himself up to stand, and takes a few steps with assistance.
Table 1
Post-hypoxic Myoclonus Cases Treated with Deep Brain Stimulation
| Age/Gender | Etiology | Body Region Affected | Preoperative UMRS | Postoperative UMRS | Medication | DBS Target/Electrode | DBS Parameters (contacts: amplitude/PW/Freq) | |||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Rest | Action | Stimulus Sensitive | Rest | Action | Stimulus Sensitive | |||||||
| Yamada et al.9 | 71M | Right putaminal hemorrhage and CPA | Right Hemibody | 24 | 52 | NA | 6 | 15 | NA | Clonazepam (1.5 mg/day) Valproate (800 mg/day) Gabapentin (400 mg/day) | Left Gpi (Medtronic 3387) | L: 1–2+1, 8V/450 µs/130 Hz |
| Kobayashi et al.10 | 36M | Perinatal anoxia | Upper limbs | NA | LUE 12 RUE 9 | NA | NA | LUE 2 RUE 2 | NA | N/A | B/L VIM (Medtronic 3387) | R: 1–3+ settings unavailable L: 1–3+ settings unavailable |
| Asahi et al.11 | 54M | CPA | Generalized | 8 | 25 | 5 | 0 | 5 | 0 | Valproate acid Clonazepam Intrathecal Baclofen | BL Gpi (Medtronic 3387) | Interleaved R: 1(–) 2(+) 2.5 V/60 µsec/125 Hz L: 0(–) 1(+) 2.0 V/60 µs/125 Hz |
| Current case | 26M | Asthmatic attack and CPA | Generalized | 751 | 52 RUE 6 RLE 2 LUE 6 LLE 2 | 0 | 0 | 32 RUE 2 RLE 2 LUE 0 LLE 2 | 0 | Clonazepam (6 mg/day) Levetiracetam (3,000 mg/day) Valproate (750 mg/day) | BL Gpi Medtronic/3389 | R: 3-c+: 2.8 V/90 µs/130 Hz L: 1-2-3-C+: 2.5 V/60 µs/130 Hz |
Table 2
Neuroimaging Findings in Post-Hypoxic Myoclonus
| Study | No. Patients | Imaging Modality | Results |
|---|---|---|---|
| Frucht et al.20 | 7 | FDG-PET | Bilateral increase in glucose metabolism in pontine tegmentum, ventrolateral thalamus, and medial temporal lobes |
| Carbon et al.21 | 7 | FDG-PET | Conjunction analysis with DYT-11 revealed shared increases in parasagittal cerebellar nuclei bilaterally |
| Park et al.22,a | 1 | rs-fMRI | Increased connectivity between: 1) primary motor cortex and right somatosensory association cortex 2) primary sensory cortex and left visual association cortex 3) supplementary motor cortex and right inferior temporal, right orbito-temporal, left primary auditory, and left somatosensory association cortex |
| Ferlazzo et al.23 | 1 | Serial MRIs | 4 days after CPA, DWI lesions in cerebellum and thalami, FLAIR was normal 20 days after CPA–DWI and FLAIR normal 6 months after CPA–3T MRI with quantitative volumetric analysis no atrophy of thalami, cerebellum, caudate nuclei, putamina, pallidus nuclei, hippocampi, as well as normal volumes of whole encephalic tissue, gray and white matter |
| Werhahn et al.2,b | 14 | MRI | Mean 2.5 years from CPA: 4 patients – mild cortical and cerebellar atrophy 4 patients – hemispheric or cerebellar infarcts 4 patients – normal |
| Zhang et al.24 | 2 | SPECT MRS FDG-PET | 1 patient 2 months from CPA SPECT – revealed mild left temporal lobe hypoperfusion 1 patient 10 months from CPA MRS – moderate reduction in N-acetyl aspartate peak in her left hippocampus and a mild decrease in the right hippocampus PET – metabolic reduction in frontal lobes |
| Huang et al.25 | 1 | fMRI | Increased BOLD bilateral cortical areas, particularly the motor cortex of legs. Of note patient has only muscle jerks in her legs |
Abbreviations: BOLD, Blood Oxygenation Level Dependent; CPA, Cardiopulmonary Arrest; DWI, Diffusion-weighted Image; FDG-PET, [18F]-fludeoxyglucose-positron Emission Tomography; MRS, Magnetic Resonance Spectroscopy; PET, Positron Emission Tomography; rs-fMRI, Resting State Functional Magnetic Resonance Imaging; SPECT - Single-photon emission computed tomography.