Movement disorders are a collection of complex neurological disorders which are characterized either by insufficient movement called Akinesia/Hypokinesia/Bradykinesia or too much movement called Hyperkinesia, ordisproportionate movement called Dyskinesia. The following are the common movement disorders:
1) Parkinson’s disease: It is a slowly progressive neurodegenerative disorder which is characterized by tremor, rigidity, slowness of movement and imbalance. Pathophysiologically, it is caused by cell degeneration in brain’s basal ganglia. These cells release a neurohormone called dopamine. Decreased level of dopamine leads to symptoms of Parkinson’s disease.
2) Dystonia: This movement disorder is characterized by sustained involuntary muscular contractions associated with twisting, repetitive movements and abnormal posture. It can be focal or generalized. Dystonia can be secondary to another disease or condition such as head trauma, drug side effect or neurological disease like Parkinson’s disease, Wilson’s disease.
3) Chorea: Chorea involves brief, nonrhythmic, jerky, random movements. It often involves athetosis which presents with twisting and writhing movements. The common cause of chorea is Huntington’s disease which is an inherited neurodegenerative disorder. In some cases, chorea is drug-induced secondary to use of anti-psychotics or anti-convulsants.
4) Tardive Dyskinesia: Tardive dyskinesia is caused by long term use of anti-psychotic drugs and dopamine receptor blockers.It is characterized by repetitive, involuntary and purposeless movements which may be manifested as grimacing, lip smacking, tongue protrusion, eye blinking, rapid movement of arms, legs and trunk.
5) Restless Leg Syndrome: Restless leg syndrome is a conditioncharacterized by strong urge for movement of legs occurring typically in the evenings or nights while sitting or lying down due to abnormal sensations in the legs. The urge is relieved with movement of legs. In most cases, the cause of restless leg syndrome is unknown.
6) Tourette’s syndrome: Tourette’s syndrome is a neurological disorder characterized by multiple repetitive episode of motor tics and vocal tics. Typically, it is first noticed in childhood but it may also first appear in teenage years. It is predominant in males than females.