Sometimes the analysis of the posture of a patient with cervical dystonia can be tricky; For instance the horizontal translation of the head is a movement that the dancers from Bali can do side to side so graciously. For us European it’s far from natural to dissociate the movement of the head from the neck in a side to side shift. Dystonic patients sometimes have their head shift to one side ….
The Bali’s dancers head posture in patients with neck dystonia.
The horizontal shift of the head.
Sometimes the analysis of the posture of a patient with cervical dystonia can be tricky; For instance the horizontal translation of the head is a movement that the dancers from Bali can do side to side so graciously. For us European it’s far from natural to dissociate the movement of the head from the neck in a side to side shift. Dystonic patients sometimes have their head shift to one side without a lateral tilt and complained of limitation of their active head and neck movements in daily life. How to analyse this dystonic posture is very important when treating the patient with Botulinum toxin injections.
Professor Reichel from Germany kindly sent me 2 weeks ago the latest English version of his book: Therapy guide spasticity-dystonia, which is a very comprehensive and practical guide of the use of Botuinum toxin in these spasticity and dystonia and reflects his vast clinical experience in these fields.
He illustrates in details the horizontal shift of the head with the underlying principle that the role of the muscles in head and neck posture depends of their insertion either on the cervical spine ( Levator scapulae, Scalenius) or on the head itself , mastoid, linae nuchae ( Sterno-cleido-mastoid, Trapezius, Splenius capitis).
The horizontal shift of the head to the right for instance will occur if at the same time the head is tilt to the left and the neck to the right. Prof Reichel uses the terminology of left laterocaput and right laterocollis.
The right levator scapulae and the right scalenius are responsible of the right laterocollis and the left Sterno-cleido-mastoid muscle, the left cervical portion of the Trapezius, and the left Splenius are responsible of the left laterocaput.
It seems complicated to follow but it’s quite obvious when examining the dystonic patient with the Bali’s dancer head posture.
But is this posture a primary dystonic posture or the results of an adaptation of the patient ‘s neck posture with a left laterocaput in order to keep the eye line straight when looking in front? There is a reflex loop between eye movement and neck muscles (the cervico-ocular reflex- COR), which with other reflexes prevents visual slip during head and body motion. But this reflex had been found weak or absent in cervical dystonia.
There is still a lot of unexplained observation in dystonia. Fortunately it does not stop neurologists to treat their patients with cervical dystonia with Botulinum toxin injections, based on a careful analysis of the posture.
Dr Marie-Helene Marion
Therapy Guide Spasticity: Dystonia (Uni-Med Science) G. Reichel
Cervico-ocular function in patients with spasmodic torticollis
R Stel, M Gresty,T Metcalfe, AM Bronstein.