[Parkinsonian dystonia]

Dystonias are frequently observed in Parkinson's disease or other parkinsonian syndromes. They can occur during off-periods, either in the morning (early morning dystonia) or during daily off-periods, and during on-periods. Dystonia involves more frequently the upper and lower limbs, the neck or the face. Dystonia can be painful in particular off-period feet dystonia. The mechanisms underlying dystonia are not fully understood, basal ganglia activity and levodopa levels seems to play an important role. There are several medical options to try and improve those dystonias, adjustment of levodopa doses, adding a dopamine agonist drug, anticholinergics, lithium, baclofene or clonazepam. Those options are not always very effective. Botulinum toxin injections are an alternative treatment for focal dystonia. Muscles have to be selected by observation of the dystonia. Deep muscles in particular in the legs can be injected under EMG guidance. Botulinum toxin injections are particularly helpful and safe for lower limb dystonia. They can be used also for other forms of dystonia. Upper limb dystonia can be injected, allowing more comfort and easier hygiene but not necessarily better function, weakness is the main side effect. Cervical dystonia, blepharospam and oromandibular dystonia can be managed the same way as idiopathic dystonia. The dose might be lower since the muscles are usually not as hypertrophic. Side effects are as expected dysphagia and neck weakness in case of cervical dystonia, ptosis, inocclusion and diplopia in case of blepharospasm, jaw opening difficulty with oromandibular dystonia. Basal ganglia surgery can also help dystonia in a selected population of parkinsonian patients.