Diagnosing non-parkinson's movement disorders.

The risk of developing a movement disorder increases with age. Idiopathic Parkinson's disease (IPD), is probably the most well known. However, essential tremor is the most common movement disorder affecting older people. Although many sufferers can have very disabling symptoms it can be a very mild illness in some. Patients present with a symmetrical tremor of the upper limbs in 95% of cases. The tremor is less evident at rest, unlike the tremor of IPD, and there will be no rigidity or bradykinesia. Essential tremor is a mainly clinical diagnosis. A watchful waiting period may be tried. DaTSCAN can be helpful as the results will be normal in patients with essential tremor and abnormal in those with IPD. Vascular parkinsonism accounts for 4.4-12% of all cases of parkinsonism, although it is likely that many cases remain undiagnosed. The features are usually bilateral and symmetrical and often affect the lower more than the upper limbs. A history of previous stroke is common, as are the presence of cardiovascular risk factors such as hypertension and diabetes. Drug-induced parkinsonism is the second most common cause of parkinsonism behind IPD. All patients thought to have a diagnosis of possible IPD should be referred to secondary care. It would also be prudent to refer any patients whose diagnosis is unclear and where advice would be helpful on future management.