Dyskinesias, drug-induced

Thalamotomy and thalamic DBS, while effective against parkinsonian tremor, have been largely abandoned since they do not treat akinesia or bradykinesia. Interventions at the level of the STN or GPi are effective against akinesia, bradykinesia rigidity, tremor, as well as disabling drug-induced dyskinesias and dystonia. 

Tardive dystonia can make an individual appear unsympathetic or bizarre, especially to the uninformed observer, who equates the facial grimaces or neck distortions with being crazy. As in all the drug-induced dyskinesias, the individual may try to cover up the disorder with additional movements that make the disorder seem voluntary and therefore not a product of mental illness. The result can be very confusing and even distressing to the observer. I have read several medical records in which... 

Preiiminary data suggest that trazodone may be effective treatment for drug-induced dyskinesias, perhaps in part because it reduces accompanying anxiety... 

In 17 parkinsonian patients three tests of proprioception were carried out 1 hour after the administration of levodopa or a dopamine receptor agonist (18). Although data were not provided for individual patients, there was an overall 11-31% deterioration in the mean scores in all three of the tests. There was no difference between patients with and without dyskinesias, but the authors suggested that abnormal proprioception may be a factor in drug-induced dyskinesia. 

Loonen AJ, Ivanova SA (2013) New insights into the mechanism of drug-induced dyskinesia. CNS Spectr 18 15-20... 

Identify the drugs used in management of tremor, Huntington s disease, drug-induced dyskinesias, and Wilson s disease. 

Turek, I. S. (1975) Drug induced dyskinesia reality or myth Dis. nerv. Syst., 36, 397. 

Henry, B and Brotchie, JM (1996) Potential of opioid antagonists in the treatment of levodopa, induced dyskinesias in Parkinson s disease. Drugs and Ageing 9 149-158. 

The main indications for atypical antipsychotics are the acute and maintenance treatment of schizophrenic disorders, with an emphasis on the treatment of refractory and chronic disorders. However, because of the lower risk of EPS and in particular of tardive dyskinesia, there is a tendency toward a wider range of indications for some of the atypical neuroleptics. Favorable effects in drug-induced psychoses have been demonstrated for olanzapine. Clozapine seems effective in the treatment and relapse prevention of manic episodes and bipolar disorders, and risperidone has been shown to have good efficacy in conduct disorders and in the pervasive developmental disorders. 

FIGURE 11-5. Long-term blockade of dopamine 2 receptors by dopamine 2 antagonists in the nigrostriatal dopamine pathway may cause these receptors to up-regulate. A clinical consequence of this may be the hyperkinetic movement disorder known as tardive dyskinesia. This up regulation may be the consequence of the neuron s futile attempt to overcome drug-induced blockade of its dopamine receptors. 

Colosimo C, Craus A (2003) Noradrenergic drugs for levodopa-induced dyskinesia. Clin. Neuropharmacol. 26 299-305. 

I have evaluated several children and young adults who developed severe cases of tardive dyskinesia following neuroleptic treatment for Tourette s. One, a 20-year-old man who had been treated with Risperdal, eventually recovered from Tourette s. However, his drug-induced severe abnormal tongue movements and jaw spasms have required treatment with Botox, and he may never fully recover from them. He had been able to live a happy and largely unimpaired life with Tourette s but the TD has severely impaired his school, occupational, and social life. 

Drug-induced disruption of dopamine neurotransmission is known to produce a variety of neurological side effects (see chapters 3 and 5). The neuroleptics suppress dopamine neurotransmission, causing a reactive hyperactivity of the system that produces a high rate of irreversible dyskinesias, cognitive dysfunction, and dementia. 

Gomez-Mancilla B, Bedard PJ (1993) Effect of nondopaminergic drugs on L-dopa-induced dyskinesias in MPTP-treated monkeys. Clin Neuropharmacol 76 418 427. 

The CYP2D6 genotype is not a determinant of susceptibility to acute dystonic reactions, but may be a contributory factor in neuroleptic drug-induced movement disorders, including tardive dyskinesia (176). 

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