Myopathies and Dystonia
Myopathy: an accurate family, drug and social history are vital.
- muscular dystrophies
- metabolic myopathies
- dermatomyositis and polymyositis
- polymyalgia rheumatica (Rheumatology)
- drug-induced myopathy
- rippling muscle disease
Investigations in Primary Care
- calcium, potassium, magnesium (HypoCalcaemia a cause)
- thyroxine and cortisol levels (Hypothyroidism,Cushings Syndrome)
- creatine kinase: elevated levels signify muscle damage
- ESR: raised in polymyalgia rheumatica
Dystonia is an involuntary muscle spasm which leads to sustained abnormal postures of the affected body part. Typically, the abnormal postures are not fixed, and slow writhing movements can occur (athetosis) where the dominant muscle activity switches from agonist to antagonist and back again. Tremor commonly occurs with dystonia and tends to affect the same body part. Dystonia can be focal or generalised.
Primary Dystonia may be genetic or idiopathic, 2ndry caused by basal ganglia damage e.g. trauma, tumour, stroke or Dopamine antagonists e.g. antipsychotics, again history is important.
Treatment for common forms of adult onset dystonia such as cervical dystonia, facial dystonia, oromandibular dystonia and blepharospasm is possible with injections of botulinium toxin. Medication can assist some types of dystonia.
Referral: Neurology for all suspected muscle disorders-Myopathy and Dystonia, Rheumatology interested in Polymyalgia Rheumatica.
Dr Stewart has an interest in Dystonia treatment and provides a Botulinum Toxin service.