Video 1
Clinical Presentation of the Patient Described in the Paper before and after Treatment with SBX. The first part of the video documents our patient’s baseline examination. There is prominent myoclonus at rest and with action. The second part of the video presents the clinical outcome after 1 hour of administration of SBX 2 g. Myoclonus at rest is abolished, and there is significant improvement of action myoclonus.
Table 1
Demographic and Clinical Features of the Patient Reported in This Study and Previous Cases Described in the Literature
| Resting | Stimulus-induced | Action | Negative | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| This case | 1 | 19 | <1 | Bilateral PNX | 6 min | VA (1,000 mg), LEV (1,000 mg), ZLP (5 mg) | 2 g QID | 3 hours | ↓↓ | ↓↓ | ↓ | ↓ | None |
| 26 | 2 | 34 | <1 | Anesthesia | NA | CZM, VA, PBT, TPM, ZNS, LEV | 2.5 g/4 hours | 3.5 hours | ↓↓ | ↓↓ | ↓ | No effect | dizziness |
| 25 | 3 | 31 | NA | Cardiac arrest – drug overdose | NA | LEV 2,500 mg, CZM 6 mg, PBT 60 mg, ALPZ 0.5 mg, rabeprazole 20 mg, BACL 20 mg, VA, TZ, PRM, GPT, PX, PIR | 2 g TID | 3.5–4 hours | ↓↓ | ↓↓ | ↓ | NA | HA, asthma, sedation and mild disinhibition |
| 30 | 4 | 61 | NA | NA | NA | CZM, LEV, ZNS | 2 g | NA | ↓a | ↓↓a | ↓↓a | NA | NA |
| 30 | 5 | 39 | NA | NA | NA | CZM, VA, LEV | 2 g | NA | ↓a | ↓↓a | ↓↓a | NA | NA |
| 30 | 6 | 62 | NA | NA | NA | CZM, LEV, ZNS, VA | 2 g | NA | ↓a | ↓↓a | ↓↓a | NA | NA |
| 30 | 7 | 38 | NA | NA | NA | CZM, LEV, L-5-HTP, PBT, PIR, TPM, VA | 2 g | NA | ↓a | ↓↓a | ↓↓a | NA | NA |
| 29 | 8 | 16 | 1 | Bilateral PNX | 7 minutes | PIR (36 g), LEV (4,000 mg), CZM (11.25 mg), VA (2,200 mg) 5-HTP (1,200 mg) | 2 g every 4 hours | NA | ↓↓ | ↓↓ | ↓ | No effect | Somnolence, GI distress |
Abbreviations: ALPZ, Alprazolam; AOO, age of onset; BACL, baclofen; CZM, clonazepam; GI, gastrointestinal; GPT, gabapentin; HA, headache; LEV, levetiracetam; NA, not available; PBT, phenobarbital; PIR, piracetam; PRM, primidone; PX, paroxetine; TPM, topiramate; TZ, tizanidine; VA, valproic acid; ZLP, zolpidem; ZNS, zonisamide.
Table 2
Outcome Measures
| Scores | |||||||
|---|---|---|---|---|---|---|---|
| Section 1 (Patient Questionnaire) | |||||||
| 26 | 1 | 33 | / | 31 | / | 25 | 18 |
| 25 | 1 | 33 | / | / | / | 31 | / |
| 29 | 1 | 60 | 60 | 58 | 48 | / | / |
| Section 2 (Myoclonus at Rest) | |||||||
| 26 | 1 | 21 | / | 8 | / | 3 | 1 |
| 25 | 1 | 3 | 3 | 0 | 0 | 3 | / |
| 29 | 1 | 128 | 120 | 41 | 0 | / | / |
| Section 3 (Stimulus Sensitivity) | |||||||
| 26 | 1 | 12 | / | 5 | / | 1 | 1 |
| 25 | 1 | 8 | 3 | 1 | 2 | 3 | / |
| 29 | 1 | 17 | 17 | 15 | 10 | / | / |
| Section 4 (Myoclonus with Action) | |||||||
| 26 | 1 | 108 | / | 70 | / | 64 | 53 |
| 25 | 1 | 108 | 96 | 64 | 54 | 86 | / |
| 29 | 1 | 112 | 112 | 66 | 40 | / | / |
| Section 5 (Functional Tests) | |||||||
| 26 | 1 | 20 | / | 10 | / | 8 | 7 |
| 25 | 1 | 20 | 20 | 13 | 12 | 15 | / |
| 29 | 1 | 20 | 20 | 19 | 14 | / | / |
| Section 6 (Global Disability Score) | |||||||
| 26 | 1 | 3 | / | 2 | / | 2 | 2 |
| 25 | 1 | 4 | 3 | 3 | 2 | 3 | / |
| 29 | 1 | 4 | 4 | 4 | 2 | / | / |
[i] Note: Scores for the different sections of the Unified Myoclonus Rating Scale (UMRS) that were available in the literature are reported in the table. Different doses of SBX were tested in each patient. The scores for the different dosages administered to each patient are reported. Section 1 (patient questionnaire): range 0–44; Section 2 (myoclonus at rest): range 0–108; Section 3 (stimulus sensitivity): range 0–17; Section 4 (myoclonus with action): range 0–160; Section 5 (functional tests): range 0–28; Section 6 (global disability score): range 0–4.
Figure 1
Graphic Representation of the Outcome Measure of the UMRS before and after Treatment with Sodium Oxybate (SBX).The average of the scores for the six sections of the UMRS was calculated from patient data available in the literature. Scores were calculated before and after treatment with the most effective dose of SBX for each patient. Pre- and post-treatment average scores are reported next to each vector. Subscore for each patient and dosages of SBX are reported in Table 2.