Tremor is very commonly seen in cervical dystonia, and correlates with the duration and severity of the dystonia.
The most common subtype seen is torticaput, possibly related to greater involvement of antagonistic muscles being active in this particulary subtype, antagonistic muscles being passively tensed by abnormal movements/postures.
Laterocaput and laterocollis are less commonly seen.
Bilateral injections are usually performed in muscles that are active synchronously to tremor..
If there is a clearly recognizable directional preponderance, as in jerky head tremors, muscle selection will take into account the most prevalent direction of pulling of the head.
No-No tremor
No-no: OCI typically involved.
For noâ€no tremor, the initial dose for this muscle is 10â€20 units of onabotulinumtoxinA per side (total dose 20â€40 units),
Traditinally injected muscles include:
Splenius capitis - 2x50U, 2 x 10-12.5 u max 60 u Botox or 2 x 40-50 U Dysport , max 250 U
Semispinalis capitis 2x20-30U
(vv)44.mp4 (tt)
Yes-Yes tremor
Muscles for injection include:
Semispinalis capitis 2x20-30U
Include SCM 2 x 20 IE bilateral
Consider splenius capitis (2 x 10-12.5, max 60 u Botox OR 2 x 40-50 u Dysport, max 250 u)
For some head tremors, the levator scapulae and the longissimus capitis may also be injected.