Drug-induced neurological disorders.

When a patient presents with a neurological or neuromuscular disorder, it is essential to consider drugs as a possible cause. Drugs can affect virtually any part of the neuraxis and the resulting disorders can usually be classified in terms of the anatomical site affected and the clinical presentation. In general, the signs and symptoms of drug-induced neurological disorders are virtually indistinguishable from those seen in naturally occurring disease but are usually reversible if diagnosed early enough. Cortical depression may produce coma, particularly in overdose cases, but a large number of drugs can also initiate seizures in susceptible individuals. The effects of drugs in the pathogenesis of headaches are certainly underestimated, and the eye, hearing and balance mechanisms can be severely damaged by certain drugs before symptoms prompt investigation. The long term effects of antipsychotic drugs on basal ganglia demand that these drugs are used only when absolutely essential and for as short a period as possible. Finally, there is increasing awareness of the role of drugs in the development of neuromuscular disorders such as peripheral neuropathies, myasthenic syndromes and myopathies.