neck muscles – Infodystonia

What makes my head turn? Find out with Dr Marion, neurologist which muscles of the neck are responsible of turning the head on one side in neck dystonia

What makes my head turn?

The neck muscles involved in the involuntary posture in cervical dystonia need to be identified for Botulinum toxin injections and physiotherapy. Here are some hints.

See the sketche below.

The head is placed on the top of the cervical spine and can pivot about 90 degrees on both sides. The pivot of the head is possible if one neck muscle is pulling forward and if another one on the other side is pulling backward.

The Sterno-Cleido-Mastoid (SCM) muscle

is the muscle pulling forward and rotating the head to the opposite side (right SCM turns the head to the left).

The Splenius Capitis

is the muscle pulling the head backward and rotating the head to the same side (left Splenius turns the head to the left).

The SCM muscle is a long superficial muscle easy to palpate on the front of the neck, and the Splenius is a deep muscle, difficult to palpate, behind the ear.

The shoulder muscles

In addition, there are 2 muscles which are both neck and shoulder muscles: the Levator scapulae and the Trapezius ; both lift up the shoulder, but the Levator scapulae is a deep muscle, responsible for the posture “shoulder up and forward “ and works with the Splenius in turning the head to the same side (the left Levator Scapulae will contribute with the left Splenuis to the rotation of the head to the left, )

The Trapezius is a superficial muscle and can contribute to the rotation of the head to the opposite side, working together with the SCM (the right Trapezius will contribute with the right SCM to the rotation of the head to the left).

These muscles are the most frequent targets for Botulinum toxin injections to control the dystonic rotation of the head. The palpation of these muscles is important, as dystonic muscles feel more bulky under the fingers.

It may sound complex but looking at the drawing should make it simpler to grasp…

Marie-Helene Marion

London BTX centre

Cervical dystonia: what does the examination look for? Dr Marion tells you how the clinical examination is important to optimise the Botox treatment.

Cervical dystonia: what does the examination look for?

Patients with cervical dystonia described at onset an intermittent feeling of pulling in the neck muscles; over the months, the head take an abnormal posture. Torticollis is defined by the head (the chin) turned to one side; laterocollis by the head tilt toward one shoulder; retrocollis by the head pulled backward in extension, chin up; antecollis by the head flexed downward, chin down to the chest. These abnormal postures are due to the involuntary movement of the neck on the trunk. There is also the possibility of abnormal movement of the head on the neck, the head going forward like a goose or going backward giving a double chin posture.

The diagnosis of cervical dystonia is made on the involuntary movement and the abnormal posture of the head, and often delays by many years from the onset of symptoms. They are other rare causes of abnormal posture of the head that a neurologist can exclude by a neurological examination and investigations.

But like the BSP, every patient is different and need to be examined carefully to document precisely the abnormal dystonic posture to know which muscle is pulling too much! Then these muscles, which are responsible of the pulling, will be the one to inject with Botulinum toxin. The difficulty comes from the action of the neck muscles which are often mixed (rotating the head on one side and tilting on the other side), resulting in mixed abnormal posture of the head (predominant rotation with a degree of tilt and extension).

It’s best to see the patient at his worst!

The patient is asked to walk, to stand up, to write or to lie down depending of the triggering factors. Usually the worst posture is achieved standing, eyes closed. The fixation of the eyes on an object helps the person to keep the head straight; when closing the eyes, the head lost the visual cue and shift to its maximal abnormal posture. Then to write down the degrees of the rotation, tilt, extension and flexion to be able at the next visit to assess the improvement under treatment.

It’s also important to see the patient at his best!

I ask the patient if he has a “geste antagoniste” (French expression also used by the Anglo-Saxons neurologists!); for instance stopping the pulling in rotation by touching with one finger the cheek without exerting an opposing force to the movement. What’s count is the improvement of the pulling by simply touching a part of the head or neck. It’s also called sensory trick and it’s a hallmark of the dystonic phenomenon.

Then when the posture is clearly documented, identifying which are the leading muscles behind, is based on surface anatomy (palpation) and functional anatomy (which muscle is doing what!).