Фокалды дистония: Белгілері, себептері және емдеу жолдары

Medical condition
Focal dystonia, also called focal task specific dystonia, is a neurological condition that affects a muscle or group of muscles in a specific part of the body during specific activities, causing involuntary muscular contractions and abnormal postures. There are many different types of focal dystonia, each affecting a different region of the body. For example, in focal hand dystonia, or writer's cramp, the fingers either curl into the palm or extend outward without control. In musicians, the condition is called musician's focal dystonia, or simply, musician's dystonia. In sports, it may be involved in what is commonly referred to as the yips. The condition appears to be associated with over training, and individualized treatment strategies may involve medications, retraining techniques, and procedures.

People with dystonia experience tightness, cramping, fatigue, involuntary sustained or repetitive muscle contractions that can be painless or painful and resulting in abnormal posturing, twisting motions, and even tremors. Focal dystonia typically presents in adults, more commonly in women ranging from ages 30 through 40. These focal dystonias can be exclusive to specific tasks, like writing or playing an instrument. Focal dystonia will typically have a subtle and slow onset before slowly worsening over years. When the brain tells a given muscle to contract, it simultaneously silences muscles that would oppose the intended movement. It appears that dystonia interferes with the brain's ability to inhibit those surrounding muscles, leading to loss of selectivity. Exploration of this initially involved over training particular finger movements in non human primates, which resulted in the development of focal hand dystonia. Examination of the primary somatosensory cortex in the trained animals showed grossly distorted representations of the maps pertaining to the fingers when compared to the untrained animals. Also, synchronous afferent stimulation of peripheral muscles induces organizational changes in motor representations, characterized both by an increase in map size of stimulated muscles and a reduction in map separation, as assessed using transcranial magnetic stimulation. The cross connectivity between areas that are normally segregated in the sensory cortex may prevent normal sensorimotor feedback and so contribute to the observed co contraction of antagonist muscle groups, and inappropriately timed and sequenced movements that underlie the symptoms of focal dystonia. It is hypothesized that a deficit in inhibition caused by a genetically mediated loss of inhibitory interneurons may be the underlying cause of the deficits observed in dystonia. Focal dystonia is generally "task specific," meaning that it is only problematic during certain activities. The main types of are blepharospasm, oromandibular dystonia, spasmodic dysphonia, spasmodic torticollis, and limb dystonia, all affecting a different region of the body. Focal dystonias involving ? are commonly misdiagnosed. A provider can rule in or out dopamine responsive dystonia with a levodopa trial. If possible, incorporating rest earlier to symptom onset has shown to have greater improvement in symptoms for writer's cramp. Bass guitarist and instructor Scott Devine said that he wears a glove while playing bass guitar because of the condition. He finds that the glove stops the involuntary finger movements. He says it works for him but does not suggest that it may work for everyone with the condition.