The syndrome of motor restlessness--a treatable but under-recognised disorder.

Editorial The syndrome of motor restlessness-a treatable but under-recognised disorder The syndrome of motor restlessness, or akathisia, is a movement disorder characterised by an irresistible purpo-seless urge to move about and, in most cases, a sense of inner tension and agitation. During the attack, patients become extremely restless and are unable to sit or stand still. Rarely, akathisia is confined to the lower limbs and in these cases patients stamp their feet repeatedly or cross and uncross their legs without having the urge to walk. In severe cases the syndrome is associated with emotional distress and suicidal attempts have been reported in some patients.1 2 Akathisia may also be accompanied by painful oral and genital sensations.3 These consist of unpleasant paraesthesiae, burning or lancinating pain that does not respond to analgesic drugs, nonsteroidal anti-inflammatory agents, phenytoin or carbamazepine. The onset of drug-induced akathisia may be acute or the syndrome may develop after months or years of exposure to neuroleptic and antidepressant agents (tardive akathisia). Akathisia is a relatively common but under-recognised extrapyramidal syndrome. The prevalence of this disorder in the general population is not known. However, it is very common in psychiatric patients, occurring in about 30-40% of patients treated with neuroleptic drugs.4 The syndrome has also been reported to be the commonest extrapyramidal adverse effect of antidepressants which selectively inhibit serotonin re-uptake, accounting for 45% of all movement disorders associated with these drugs.5 Interestingly, akathisia due to these drugs tends to occur mostly in younger patients, especially women, whereas dystonia, parkinsonism and tardive dyskinesia are found more frequently in older patients. Aetiology In most cases akathisia is drug-induced, although it may rarely occur in untreated patients with idiopathic and post-encephalitic parkinsonism6 and following traumatic brain injury. The commonest drugs which cause akathisia are neuroleptic drugs and serotonin re-uptake inhibitors used for the treatment of depression.5'7 Lithium has also been implicated in some cases.8 The syndrome may complicate treatment with levodopa in parkinsonian patients and has also been reported following the withdrawal of tricyclic antidepressants (box 1). Akathisia due to neuroleptic medication is by far the most frequently encountered entity.4 Interestingly, some Drug-induced akathisia * neuroleptic agents: some are more likely than others to cause akathisia, eg, haloperidol>risperidone; chlorpromazine> thioridazine * serotonin re-uptake inhibitors: akathisia most frequently caused by fluoxetine and paroxetine * other antidepressants: sudden withdrawal of tricyclic antidepressants, combination of monoamine oxidase inhibitors with fluoxetine or tryptophan * …