Brain damage and tardive dyskinesia

Tardive Dyskinesia-like Syndrome Due to Drugs that do not Block Dopamine Receptors: Rare or Non-existent: Literature Review

Background

Although tardive dyskinesia (TD) is most commonly defined as a movement disorder caused by chronic exposure to dopamine‐receptor‐blocking drugs (DRBDs), it has also been thought to result from exposure to some non‐DRBDs.

Methods

We critiqued many reviews making the association between non‐DRBDs and a TD‐like syndrome and almost all case reports. We checked whether cases met criteria for the diagnosis of TD‐like syndrome and whether DRBDs had been excluded.

Results

We found that both tricyclic antidepressants and selective serotonin reuptake inhibitor antidepressants may unmask or exacerbate TD after prior exposure to or with concurrent use of DRBDs. We found support for its existence outside of this context to be extremely weak.

Discussion

There is little evidence that drugs other than DRBDs by themselves cause a TD syndrome; most reported cases appear to occur as a result of a “priming” effect induced by a DRBD, which is later unmasked.

SSRIs do not worsen Parkinson's disease: evidence from an open-label, prospective study

Selective serotonin reuptake inhibitors (SSRIs) have been reported to be useful in the treatment of depression in patients with Parkinson's disease (PD). However, a few reports have suggested that SSRIs may worsen parkinsonian motor symptomatology and extrapyramidal side effects have been reported in depressed patients treated with SSRIs. So far, no prospective trial comparing the effects of different SSRIs in depressed patients with PD has been performed. The aim of the present study was to assess the effects of four SSRIs (citalopram, fluoxetine, fluvoxamine, and sertraline) on motor performance and their efficacy on depression in a group of patients with PD. Sixty-two consecutive nondemented, nonfluctuating, depressed patients with PD were included in four treatment groups (15 patiens received citalopram, 16 fluoxetine, 16 fluvoxamine, and 15 sertraline). The evaluation of extrapyramidal and depressive symptomatology was performed with use of the Unified Parkinson's Disease Rating Scale (UPDRS), Beck Depression Inventory, and Hamilton Depression Rating Scale at baseline and after 1, 3, and 6 months. Fifty-two patients completed the study. UPDRS scores were not significantly modified by the add-on therapy with each of the SSRIs studied. A significant improvement in depressive symptoms from baseline to the end of the trial was obtained with all SSRIs (Beck and Hamilton scores improving; p < 0.05 according to an analysis of variance). Our findings suggest that SSRIs do not significantly worsen extrapyramidal symptomatology and may ameliorate depression in patients with PD.

SSRI-induced extrapyramidal side-effects and akathisia: implications for treatment

The selective serotonin reuptake inhibitors (SSRIs) may occasionally induce extrapyramidal side-effects (EPS) and/or akathisia. This may be a consequence of serotonergically-mediated inhibition of the dopaminergic system. Manifestations of these effects in patients may depend on predisposing factors such as the presence of psychomotor disturbance, a previous history of drug-induced akathisia and/or EPS, concurrent antidopaminergic and/or serotonergic therapy, recent monoamine oxidase inhibitor discontinuation, comorbid Parkinson's disease and possibly deficient cytochrome P450 (CYP) isoenzyme status. There is increasing awareness that there may be a distinct form of melancholic or endogenous depression with neurobiological underpinnings similar to those of disorders of the basal ganglia such as Parkinson's disease. Thus, it is not surprising that some individuals with depressive disorders appear to be susceptible to developing drug-induced EPS and/or akathisia. In addition, the propensity for the SSRIs to induce these effects in individual patients may vary within the drug class depending, for example, on their selectivity for serotonin relative to other monoamines, affinity for the 5-HT2C receptor, pharmacokinetic drug interaction potential with concomitantly administered neuroleptics and potential for accumulation due to a long half-life. The relative risk of EPS and akathisia associated with SSRIs have yet to be clearly established. The potential risks may be reduced by avoiding rapid and unnecessary dose titration. Furthermore, early recognition and appropriate management of EPS and/or akathisia is required to prevent the impact of these effects on patient compliance and subjective well-being. It is important that the rare occurrence of EPS in patients receiving SSRIs does not preclude their use in Parkinson's disease where their potentially significant role requires more systematic evaluation.

Selective serotonin-reuptake inhibitor-induced movement disorders

OBJECTIVE

To compile and evaluate all available data suggesting an association between selective serotonin-reuptake inhibitor (SSRI) administration and the occurrence of movement disorders, and to characterize these reactions in terms of onset, duration, treatment and outcome, and potential predisposing factors.

METHODOLOGY

Reports of movement disorders were identified by conducting a comprehensive literature search that included tertiary adverse drug reaction resources, MEDLINE, EmBASE, Biological Abstracts, Current Contents, Reactions, ClinAlert, and International Pharmaceutical Abstracts. In addition, reports were solicited from the Canadian proprietary manufacturers of SSRIs, and from the Therapeutic Products Program of Health Canada. Each case was then classified according to the description of the movement disorder, based on predefined diagnostic criteria.

RESULTS

A total of 127 published reports of SSRI-induced movement disorders were identified involving akathisia (n = 30), dystonia (19), dyskinesia (12), tardive dyskinesia (6), parkinsonism (25), and 15 cases of mixed disorders. Ten isolated cases of bruxism were identified. Ten additional reports could not be classified. Manufacturers of SSRIs provided 49 reports of akathisia, 44 of dystonia, 208 of dyskinesia, 76 of tardive dyskinesia, 516 of parkinsonism, and 60 of bruxism. Treatment strategies included discontinuation of the SSRI; dosage reduction; or the addition of a benzodiazepine, beta-blocker, or anticholinergic agent.

CONCLUSIONS

SSRI use appears to be associated with the development of movement disorders, as either a direct result of the drug or exacerbation of an underlying condition. Predisposing factors may include the use of neuroleptics, existing neurologic diagnoses, or preexisting movement disorders. Clinicians should be cognizant of the potential for these reactions, as prompt recognition and management is essential in preventing potentially significant patient morbidity.