Table 1
Demographic data and main subtypes of idiopathic cervical dystonia patients with (DHT+) and without (DHT–) dystonic head tremor.
| DHT+ | DHT– | p value | |
|---|---|---|---|
| Total number of patients | 169 (57.6%) | 124 (42.3%) | – |
| Age [Mean ± standard deviation (SD), Range] years | 56.2 ± 13.11, 23–90 | 54.2 ± 12.61, 29–74 | 0.19 |
| Sex (Male: M; Female: F) | F: 120 (71.0 %) ; M: 49 (29.0 %) | F: 77 (62.1 %); M: 47 (37.9 %) | |
| Duration of illness (Mean ± SD, Range) in years | 11.8 ± 8.69, 0.5–39 | 9.5 ± 8.91, 0.6–51 | 0.02 |
| Number of subtypes | |||
| One subtype | 35 (20.7%) | 14 (11.2%) | 0.03 |
| Two subtypes | 72 (42.6%) | 49 (39.5%) | 0.59 |
| Three subtypes | 37 (21.8%) | 32 (25.8%) | 0.43 |
| Four subtypes | 20 (11.8%) | 21 (16.9%) | 0.21 |
| Five subtypes | 05 (02.9%) | 06 (04.8%) | 0.40 |
| Six subtypes | 00 | 02 (01.6%) | – |
| Main subtype | |||
| Torticaput | 97 (57.3%) | 50 (40.3%) | 0.01 |
| Laterocaput | 22 (13.0%) | 25 (20.1%) | 0.09 |
| Laterocollis | 18 (10.6%) | 12 (9.6%) | 0.78 |
| Torticollis | 12 (7.1%) | 14(11.2%) | 0.21 |
| Retrocaput | 7 (4.1%) | 7 (5.6%) | 0.55 |
| lateral shift | 5 (2.9%) | 00 | 0.19 |
| Retrocollis | 4 (2.3%) | 4 (3.2%) | 0.65 |
| Anterocollis | 2 (1.1%) | 6 (4.8%) | 0.05 |
| Anterocaput | 1 (.05%) | 4 (3.2%) | 0.08 |
| Anterior sagittal shift | 1 (.05%) | 1 (.05%) | 0.82 |
Table 2
Details of the muscles injected and the doses of botulinum toxin in idiopathic cervical dystonia patients with (DHT+) and without (DHT–) dystonic head tremor.
| Name of the muscle | DHT+ group (n = 169) | DHT– group (n = 124) | p value |
|---|---|---|---|
| Sternocleidomastoid unilateral | 110 (65.0%) | 87 (70.1%) | 0.36 |
| Sternocleidomastoid bilateral | 31 (18.3%) | 06 (04.8%) | 0.0005 |
| Splenius capitis unilateral | 76 (44.9%) | 66 (53.2%) | 0.16 |
| Splenius capitis bilateral | 78 (46.1%) | 25 (20.1%) | 0.00001 |
| Trapezius unilateral | 62 (36.6%) | 68 (54.8%) | 0.056 |
| Trapezius bilateral | 28 (16.5%) | 09 (07.2%) | 0.01 |
| Levator scapulae unilateral | 61 (36.0%) | 54 (43.5%) | 0.19 |
| Levator scapulae bilateral | 13 (07.6%) | 13 (10.4%) | 0.40 |
| Semispinalis capitis unilateral | 60 (35.5%) | 37 (29.8%) | 0.30 |
| Semispinalis capitis bilateral | 06 (03.5%) | 10 (08.0%) | 0.09 |
| Obliquus capitis inferior unilateral | 45 (26.6%) | 41 (33.0%) | 0.23 |
| Obliquus capitis inferior bilateral | 15 (08.8%) | 02 (01.6%) | 0.008 |
| Semispinalis cervicis unilateral | 27 (15.9%) | 26 (20.9%) | 0.27 |
| Semispinalis cervicis bilateral | 07 (04.1%) | 05 (04.0%) | 0.96 |
| Longus colli unilateral | 24 (46.1%) | 23 (18.5%) | 0.31 |
| Long colli bilateral | 02 (01.1%) | 0 | – |
| Scalenus medius unilateral | 12 (07.1%) | 12 (09.6%) | 0.42 |
| Scalenus medius bilateral | 04 (02.3%) | 06 (04.8%) | 0.24 |
| Splenius cervicis unilateral | 10 (05.9%) | 10 (08.0%) | 0.47 |
| Splenius cervicis bilateral | 0 | 0 | – |
| Total | 855 | 576 | 0.51 |
| Total dosages of botulinum toxin | |||
| OnabotulinumtoxinA [Mean ± standard deviation (SD), Range] | 99 (162.5 ± 68.5, 30–300) units | 53 (156.0 ± 49.3, 50–240) units | 0.54 |
| IncobotulinumtoxinA (Mean ± SD, Range) | 26 (175.6 ± 123.5, 50–590) units | 21 (155.8 ± 63.5, 48–270) units | 0.50 |
| AbobotulinumtoxinA (Mean ± SD, Range) | 44 (640.2 ± 216.0, 102.5–1020) units | 50 (654.5 ± 358.4, 170–1520) units | 0.81 |
Table 3
Studies reporting frequency of tremor in idiopathic cervical dystonia patients.
| Author/year | No of patients | Number of cervical dystonia patients | Frequency of head tremor | |
|---|---|---|---|---|
| Huizdosova et al [8] | 2020 | 120 | Cervical dystonia | 58.3 % (n = 70) |
| Merola et al [9] | 2019 | 1608 | Cervical dystonia | 18.1% (n = 291) |
| Gigante et al [10] | 2015 | 173 | 72 cervical dystonia patients | Overall 34% (n = 59) had tremor [12 patients- head tremor 34 patients-arm tremor 13 patients-both sites] |
| Pandey et al [11] | 2017 | 90 | Adult onset isolated dystonia Cervical dystonia-41 Limb dystonia-34 Cranial dystonia-15 | Overall 45.5% (n = 41) Cervical dystonia-21(51.2%) |
| Erro et al [12] | 2013 | 473 | Adult-onset primary dystonia patients including 207 patients with cervical dystonia | Overall 55.4% (n = 262) had tremor; 196 patients (41.4%) had head tremor |
| Defazio et al [13] | 2013 | 429 | Primary adult onset dystonia patients including 118 cervical dystonia patients | 22/34 (64.7) patients with tremor had cervical dystonia |
| Pal et al [14] | 2000 | 114 | Cervical dystonia | 68.4% (n = 78) had head tremor and 34.6% of them (27) had tremor as one of the first symptoms |
| Deuschl et al [15] | 1997 | 55 | Idiopathic spasmodic torticollis | 60% |
| Chan et al [16] | 1991 | 266 | Idiopathic cervical dystonia | 28% |
| Jankovic et al [17] | 1991 | 300 | Cervical dystonia | 71% |
| Couch et al [18] | 1976 | 30 | Torticollis | 26 (86.6%) |
| Marsden et al [19] | 1971 | 42 | Idiopathic torsional dystonia | 6 (14%) |