Table 1
Patient history and features of ET on videotaped neurological examination.
| CASE NUMBER | 1 | 2 | 3 | 4 | 5 |
|---|---|---|---|---|---|
| Age (in years) | 75 | 72 | 80 | 82 | 88 |
| Age of Tremor Onset (in years) | 14 | 35 | 50 | 25 | 14 |
| Jewish Ancestry | Yes | Yes | Yes | No | Yes |
| Family History of Tremor or ET | Mother and sister have been diagnosed with ET | Grandmother had non-specific tremor | Father, sister, and grandmother had non-specific tremor | Father and brother have been diagnosed with ET. Grandmother is suspected to have ET as well | Mother has been diagnosed with ET |
| Current Medications | atenolol | propranolol, gabapentin, duloxetine, estrodiol/norethisterone acetate | propranolol | pindolol, primidone, | mirtazapine, levothyroxine, escitalopram |
| Handedness | Right | Right | Left | Right | Right |
| Total Tremor Score (out of 36) | 25.5 | 27 | 21.5 | 29.5 | 25.5 |
| Postural Tremor Rating | Dominant: 1.0 | Dominant: 0.5 – 1.0 | Dominant: 1.0 | Dominant: 1.5 | Dominant: 1.0 |
| Non-dominant: 1.5 | Non-dominant: 0.5 – 1.0 | Non-dominant: 0.5 | Non-dominant: 0.5 | Non-dominant: 1.5 | |
| Pouring Water Tremor Rating | Dominant: 2.0 | Dominant: 2.0 – 3.0 | Dominant: 2.0 | Dominant: 3.0 | Dominant: 2.0 |
| Non-dominant: 2.0 | Non-dominant: 2.0 – 3.0 | Non-dominant: 2.0 | Non-dominant: 3.0 | Non-dominant: 2.0 | |
| Drinking from Cup Tremor Rating | Dominant:3.0 | Dominant: 2.0 – 3.0 | Dominant: 2.0 | Dominant: 3.0 | Dominant: 3.0 |
| Non-dominant: 2.0 | Non-dominant: 2.0 – 3.0 | Non-dominant: 2.0 | Non-dominant: 3.0 | Non-dominant: 2.0 | |
| Using Spoon with Water Tremor Rating | Dominant: 3.0 | Dominant: 3.0 | Dominant: 3.0 | Dominant: 4.0 | Dominant: 3.0 |
| Non-dominant: 3.0 | Non-dominant: 3.0 | Non-dominant: 3.0 | Non-dominant: 4.0 | Non-dominant: 3.0 | |
| Finger-Nose-Finger Tremor Rating | Dominant: 1.5 | Dominant: 1.5 | Dominant: 1.0 | Dominant: 2.0 | Dominant: 2.0 |
| Non-dominant: 1.5 | Non-dominant: 2.0 | Non-dominant: 1.5 | Non-dominant: 1.5 | Non-dominant: 2.0 | |
| Drawing an Archimedes Spiral Tremor Rating | Dominant: 2.0 | Dominant: 2.0 | Dominant: 2.0 | Dominant: 2.0 | Dominant: 2.0 |
| Non-dominant:3.0 | Non-dominant: 2.0 | Non-dominant: 1.5 | Non-dominant: 2.0 | Non-dominant: 2.0 |
[i] Tremor scored using the Washington Heights Genetic Study of ET Rating Scale, range = 0–3 (severe) [17].
Video 1
Case 1. On frontward arm extension, the right pinky flexes downward and there is some “spooning” (abnormal dystonic flexion of the wrist and hyperextension of the fingers) and dystonic posturing of the fingers of the left hand (extension of digits 2 and 5 as well as flexion of digit 3). In the wingbeat position, the right pinky flexes slightly but less so than described above. The head is slightly yet consistently tilted to the right. There is also a transient and subtle eyebrow tremor. At the initiation of gait, there is slight pointing of the right index finger, which lessens as he walks.
Video 2
Case 2. On frontward arm extension, there is slight flaying and extension of the 4th and 5th digits of the right hand. During the wingbeat position, the right wrist is flexed and the left pinky flexes downwards. While pouring, the left pinky extends off of the glass. While walking, there is sustained pointing on the left index finger).
Video 3
Case 3. On arm extension, there is a moderate degree of flexion of the left 3rd digit at the MCP joint. This is also present during the wing beat position.
Video 4
Case 4. On forward arm extension, there is mild hyper-extension of the right 2nd digit at the MCP joint. On the left, there is clear spooning with moderate and clear hyper-extension of the 2nd digit at the MCP joint. In the wing-beat position, the dystonia is even more evident, with mild to moderate hyper-extension of the 2nd right digit at the MCP joint, and with marked spooning on the left with hyperextension of the 2nd - 4th digits at the MCP joints and splaying of the left pinky.
Video 5
Case 5. On arm extension, left digit 2 is mildly to moderately flexed downward at the MCP joint. In the wing-beat position, the left digit 2 is again mildly flexed at the MCP joint and the pinky splays slightly outward away from the other fingers. While walking, there is subtle but consistent pointing on the right.
Table 2
Dystonic features observed by experts in each case.
| EXPERT 1 | EXPERT 2 | EXPERT 3 | EXPERT 4 | EXPERT 5 | EXPERT 6 | EXPERT 7 ** | |
|---|---|---|---|---|---|---|---|
| Case 1 | |||||||
| A. Dystonic postures of the fingers and wrist | |||||||
| A.1 Extension of the left 2nd and 5th digit during arm extension | ✓ | ✓* | ✓ | ✓ | ✓ | ||
| A.2 Flexion of the left 3rd digit during arm extension | ✓ | ✓* | ✓* | ✓* | |||
| A.3 Flexion of the right 5th digit during arm extension | ✓ | ✓* | ✓ | ||||
| A.4 Flexion of the right 5th digit during wingbeat position | ✓ | ✓* | ✓ | ||||
| A.5 Spooning of left hand during arm extension | ✓* | ✓ | |||||
| A.6 Extension of the right 2nd digit when walking | ✓* | ✓ | ✓ | ||||
| B. Cervical dystonia | ✓ | ✓ | ✓ | ✓ | ✓ | ||
| C. Craniofacial tremor | ✓ | ✓ | ✓ | ||||
| Case 2 | |||||||
| A. Dystonic postures of the fingers and wrist | |||||||
| A.1 Extension of the right 4th and 5th digit during arm extension | ✓* | ✓ | ✓ | ✓ | |||
| A.2 Flexion of right wrist during wingbeat position | ✓ | ✓* | ✓ | ✓ | |||
| A.3 Flexion of left wrist during wingbeat position | ✓* | ||||||
| A.4 Flexion of the left 5th digit during wingbeat position | ✓ | ✓* | ✓ | ✓ | ✓ | ||
| A.5 Extension of the left 5th digit while pouring | ✓ | ✓* | ✓ | ✓ | ✓ | ||
| A.6 Extension of the left 2nd digit when walking | ✓ | ✓* | ✓ | ✓ | |||
| A.7 Extension of the left 5th digit when walking | ✓ | ✓* | |||||
| Case 3 | |||||||
| A. Dystonic postures of the fingers | |||||||
| A.1 Flexion of the left 3rd digit during arm extension | ✓ | ✓* | ✓ | ✓ | ✓ | ||
| A.2 Flexion of the left 3rd digit during wingbeat position | ✓ | ✓* | ✓ | ||||
| Case 4 | |||||||
| A. Dystonic postures of the fingers and wrist | |||||||
| A.1 Hyper-extension of the right 2nd digit during arm extension | ✓* | ✓ | ✓ | ||||
| A.2 Hyper-extension of the left 2nd digit during arm extension | ✓ | ✓* | ✓ | ✓ | |||
| A.3 Hyper-extension of the right 2nd digit during wingbeat position | ✓* | ✓ | ✓ | ||||
| A.4 Hyper-extension of the left 2nd-4th digit during wingbeat position | ✓ | ✓* | ✓ | ✓ | ✓ | ||
| A.5 Splaying of left 5th digit during wingbeat position | ✓ | ✓* | ✓ | ✓ | ✓ | ✓ | |
| A.6 Spooning of left hand during frontward arm extension and wingbeat position | ✓ | ✓* | ✓ | ✓ | |||
| A.7 Flexion of left wrist | ✓ | ✓* | |||||
| B. Jerky tremor | ✓ | ||||||
| Case 5 | |||||||
| A. Dystonic postures of the fingers | |||||||
| A.1 Flexion of the left 2nd digit during arm extension | ✓* | ✓ | ✓ | ✓ | |||
| A.2 Flexion of the left 2nd digit during wingbeat position | ✓* | ✓ | ✓ | ||||
| A.3 Flexion of left 3rd digit | ✓ | ✓* | |||||
| A.4 Hyper-extension of left 4th digit | ✓ | ✓* | |||||
| A.5 Splaying of left 5th digit during wingbeat position | ✓* | ✓ | ✓ | ||||
| A.6 Extension of the right 2nd digit when walking | ✓ | ✓* | ✓ | ✓ | |||
[i] * Reported “dystonic posturing of fingers” with no further description.
** Observed many of the listed phenotypes but did not interpret them as dystonic features.
Table 3
Diagnosis assigned by experts in each case.
| EXPERT 1 | EXPERT 2 | EXPERT 3 | EXPERT 4 | EXPERT 5 | EXPERT 6 | EXPERT 7 | |
|---|---|---|---|---|---|---|---|
| Case 1 | dystonic tremor | ET + dystonia | ET + dystonia | ET + dystonia | ET + dystonia | ET | ET |
| Case 2 | dystonic tremor | ET + dystonia | ET | ET plus | ET | ET | ET |
| Case 3 | dystonic tremor | ET + dystonia | ET | ET | ET | ET | ET |
| Case 4 | dystonic tremor | ET + dystonia | ET + dystonia | ET plus | ET | ET | ET |
| Case 5 | dystonic tremor | ET + dystonia | ET | ET plus | ET | ET + PD | ET |