Cervical Dystonia
Short summary
47-year-old female with a 4-year history of cervical dystonia. She has been treated with botulinum toxin injections which were ineffective for her. In the expert's opinion, the success of Botulinum toxin in cervical dystonia depends on a thorough clinical assessment, exact targeting of the chosen muscles, and adequate doses of toxin injected. The expert also suggests additional or alternative treatment strategies: medical treatment by different oral drugs, or deep brain stimulation of the globus pallidus interna.
Medical Background
This is a 47 years old woman with a diagnosis of cervical dystonia since 2004. She has been treated with botulinum toxin injections in the past but this had been ineffective for her.
The results of two tests were documented:
1. Study of the recovery cycle of the R2 component of the blink reflex: as the clinical facial nerve reflex tests are usually normal in spasmodic torticollis, this test is not informative, and does not add important information to the patients' diagnosis or treatment.
2. Polymyographic study of the cervical muscles: this test showed the muscles that are principally involved are the right splenius capitis, the left sternocleidomastoid and to a lesser extent the left splenius capitis and there is some pain or limitation upon trying to turn the head to the left.
Medical opinion
From the tests I conclude that the patients' diagnosis is indeed cervical dystonia. I have no information concerning the impact of the disorder on the patients' functioning or quality of life and whether the rest of his neurological examination is normal- that is does he have any other abnormal findings such as parkinsonism, ataxia, radicular deficits or dystonia in other body areas.
According to the tests the main abnormal cervical posture is a rotation to the right. I have no information whether there is a tilting (latercolis) component, any anterior flexion of the head or a shoulder elevation. I have no information about hypertrophy of specific muscle or areas of tenderness. As these are lacking it is hard for me to define which muscles should be injected and what doses.
The success of Botulinum toxin injections in cervical dystonia depends on the following:
- A thorough clinical assessment of the abnormal posture of the neck, evaluation of the extent of movement limitation, presence and location of muscle tenderness and palpation for specific muscular hypertrophy.
- Exact targeting of the chosen muscles when injecting the material into the muscles (preferably by injecting through an EMG needle connected to an amplifier).
- Adequate doses of toxin injected to the chosen muscles.
Failure of treatment might reflect suboptimal assessment or performance in any one of the above items.
Presuming the patient was assessed and treated adequately there are additional or alternative treatment strategies:
- Medical treatment by oral drugs:
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- Anticholinergics: Artane (trihexyphenydil) 2 mg, started 1 mg bid and increased slowly to 2 mg tid or maximally tolerated dose (up to a total of 8 mg/day)
- Benzodiazepines: Lorazepam 1 mg, started at 1 mg at bedtime, increased weekly to 1 mg bid and then 1 mg tid. Alternatively- Clonazepam 0.5 mg, started at 0.25 mg at bedtime, increased weekly to 0.25 mg bid ,then 0.25 mg tid and increased slowly up to a maximal dose of 0.5 mg tid.
- Baclophen 10 mg: started at 5 mg bid, increased weekly to 5 mg tid and then 5 mg tid, and increased continuously to a dose of 10 mg tid and then slowly up to 20 mg tid.
These medications can be combined.
- Surgical treatment by deep brain stimulation (DBS):
DBS of the globus pallidus interna (GPi) is an effective treatment for generalized dystonia and its positive effects in the management focal or segmental dystonia is increasingly gaining support. A few studies were published in the medical literature supporting the efficacy and safety of GPi-DBS for the treatment of patients with these types of dystonia including cervical dystonia, showing beneficial effects and favorable safety.
In summary, this patient has a 4-year history of cervical dystonia, of which the severity and effect on quality of life I do not know, but which is treated sub-optimally.
