Videos:
Video 1. Examination of the First Patient before the Initiation of Levetiracetam Revealed Frequent Myoclonic Jerks of the Neck and Trunk at Rest. Ocular telangiectasia was not present. There were occasional square wave jerks. Oculomotor apraxia was demonstrated, with marked delay of saccade initiation. Once he generated saccades, they were hypometric, and saccadic velocities were slow. Pursuits were relatively preserved compared with saccades. Horizontal and vertical optokinetic nystagmus was reduced. Myoclonus of bilateral upper extremities was more prominent with action, such as when he held his arms up or moved his hand to the target. Video 2. Examination of the First Patient 9 Months after the Examination in Video 1, when the Patient was on Levetiracetam 1,000 mg/day. Neck and truncal myoclonus was mildly improved. There were less axial myoclonic jerks at rest. Myoclonus of the neck was more prominent when he tried to perform tasks such as attempting to move his eyes during the examination. Oculomotor apraxia and other ocular motility examinations had not significantly changed since the examination in Video 1. Myoclonus remained more prominent with action than at rest, but action myoclonus when holding his arms up or moving his arms had slightly improved since the examination in Video 1. The finger-following test demonstrated not only action myoclonus, but also symmetric overshoot dysmetria.
Table 1
Review of Literature of Ataxia–Telangiectasia Cases with Myoclonus
| Authors | Year Published | Number of Patients | Age Patient(s) Developed Myoclonus (years) | Phenomenology | Body Regions Involved |
|---|---|---|---|---|---|
| Saunders-Pullman et al.14 | 2012 | 8 (from 3 families; 3, 1, 4 from each) | Unknown | Myoclonus/jerky dystonia | Neck in 6 patients, arm(s) in 4, lower face in 2, upper face in 1 |
| Shaikh et al.15 | 2013 | Unknown | Unknown | All (80 patients) had non-rhythmic adventitious movements on accelerometer, classified into slow and fast movements. The fast movements were “similar to myoclonus or dystonic jerks”, but the number of the patients in this subgroup was not reported | Upper limb |
| Cummins et al.6 | 2013 | 1 | 46 | Myoclonus and dystonia | Head (myoclonus), truncal extensor muscles (dystonia) |
| Mèneret et al.2 | 2014 | 12 (out of 14 patients) | Unknown | Myoclonus with dystonia in 10 patients; multifocal myoclonus without dystonia in 2 | Neck, trunk, upper limbs |
| Nakayama et al.7 | 2014 | 1 | 8 | Myoclonic/dystonic jerks | Neck and truncal extensor muscles |
| Current cases | 2014 | 2 | 11 and 12 | Myoclonus | One in neck, face, trunk and extremities; the other in the limbs and trunk |