Computed tomographic evaluation of patients with tardive dyskinesia

N-methyl-D-aspartate receptor antibody and the choroid plexus in schizophrenia patients with tardive dyskinesia

BACKGROUND

Immune disturbance has been postulated to be one of the mechanisms underlying the pathogenesis of tardive dyskinesia (TD). Recently, the role of autoimmune abnormality in TD has been increasingly recognized. Autoantibodies against neuronal N-methyl-D-aspartate receptor (NMDAR) may be cross-reactive in the brain in neuropsychiatric disorders, and the choroid plexus (CP) is a crucial immune barrier in the central nervous system (CNS). We supposed that NMDAR antibodies might underlie the pathophysiological process of TD through the mediation of CP.

METHODS

Serum NMDAR antibody levels were assessed by enzyme-linked immunosorbent assay, CP and ventricle volumes were assessed by magnetic resonance imaging in schizophrenia patients with TD (n = 61), without TD (NTD, n = 61), and in healthy controls (n = 74). Psychopathology and TD severity were assessed by the Positive and Negative Syndrome Scale and Abnormal Involuntary Movement Scale (AIMS).

RESULTS

NMDAR antibody levels were significantly higher, CP volumes were larger in the TD group than in the NTD group (p = 0.022; p = 0.019, respectively). In the TD group, higher NMDAR antibody level was correlated with larger CP volume (β = 0.406, p = 0.002). An elevated NMDAR antibody level and enlarged CP volume were correlated with orofacial AIMS score (β = 0.331, p = 0.011; β = 0.459, p = 3.34 × 10^-4, respectively). In a mediation model, the effect of NMDAR antibody level on the orofacial AIMS score was mediated by the CP volume (indirect effect: β = 0.08, 95% confidence interval = 0.002-0.225; direct effect: β = 0.14, p = 0.154).

CONCLUSIONS

Our findings highlight a potential NMDAR antibody-associated mechanism in orofacial TD, which may be mediated by increased CP volume.

Structural brain changes associated with tardive dyskinesia in schizophrenia

BACKGROUND

The pathological basis of tardive dyskinesia is unknown. Although its clinical features implicate the basal ganglia, imaging studies have not found clear evidence that it is associated with volume changes in these or other brain structures.

AIMS

To determine, using voxel-based structural imaging, whether there are regions of grey matter volume change in people with schizophrenia who also have tardive dyskinesia compared with those without tardive dyskinesia.

METHOD

A total of 81 people with chronic schizophrenia, 32 with tardive dyskinesia and 49 without, were examined using magnetic resonance imaging (MRI) and whole-brain, optimised voxel-based morphometry. A comparison group of 61 healthy controls was also examined.

RESULTS

Compared with those without tardive dyskinesia, patients with tardive dyskinesia showed a pattern of volume reductions in predominantly subcortical regions, including the basal ganglia and the thalamus. Within the basal ganglia, volume reductions were seen in the caudate nucleus, to a lesser extent in the putamen, and only marginally in the globus pallidus. The patients with tardive dyskinesia, but not those without, showed significant volume reductions in the basal ganglia compared with the healthy controls but both groups had smaller volumes than controls in other affected areas.

CONCLUSIONS

The pathological process or processes that underlie the development of tardive dyskinesia are not just neurochemical in nature, but affect brain structure.

Managing antipsychotic-induced acute and tardive dystonia

Antipsychotic-induced extrapyramidal adverse effects continue to be a serious problem in the treatment of psychotic disorders. While the pathophysiology of these adverse effects is not well understood, much recent research has focused on improving our ability to use available pharmacotherapy in the most effective and least toxic manner. Acute dystonic reactions only occur within the first days of antipsychotic treatment. They are often distressing and frightening for the patient and may even be dangerous. However, they can be effectively prevented or reversed with anticholinergics. Furthermore, the growing use of the new atypical antipsychotics will lead to a significant decrease in the rate of acute dystonic reactions. In contrast, tardive dystonia is a long-lasting menace in the course of antipsychotic treatment, for which there is no established therapy. Tardive dystonia is sometimes disabling or disfiguring and, like other tardive disorders, is potentially irreversible. Because, in most cases, patients need to continue taking the antipsychotic that has caused the adverse effect to prevent relapse of the mental illness, preventive measures are crucial. Antipsychotics should be prescribed only for patients affected by psychotic disorders, when definitely indicated and at the lowest effective dosage. The use of clozapine and other novel antipsychotic agents is also likely to represent an important step in the prevention and treatment of tardive dystonia. Compared with traditional antipsychotics, most of the new antipsychotics are characterised by a low acute extrapyramidal adverse effects liability and they also bring the hope of reducing the risk of tardive disorders. If tardive dystonia has occurred, switching to clozapine or another atypical antipsychotic and treatment with tetrabenazine, reserpine and botulinum toxin are possible options.

Tolerability of low dose neuroleptics: a case control study of flupenthixol

There are no data available on the risk of extrapyramidal symptoms when using long-term flupenthixol in low dosage in patients suffering from anxiety and depressive disorders. In a case control study 106 patients essentially treated with the neuroleptic flupenthixol in a so-called low, non-antipsychotic dosage were compared to n=37 otherwise comparable patients who never had been treated with neuroleptics. The investigator was blind to the previous treatment conditions. Extrapyramidal symptoms were found although with a low prevalence and mild degree: 6.7% tardive dyskinesia, none in controls; pseudoparkinsonism 26%, 16% in controls. Extrapyramidal side-effects, especially tardive dyskinesia, have to be considered in the individual weighing of therapeutic benefits and risks even when prescribing flupenthixol in low dosages.

Caudate nucleus morphology in tardive dyskinesia

OBJECTIVE

The objective of this project was to test whether there are differences in the size of the caudate nucleus in schizophrenic in-patients with and without tardive dyskinesia.

METHOD

The study was cross-sectional in design, examining group differences between institutionalised schizophrenic patients with and without tardive dyskinesia, using non-enhanced computerised tomography scans of the brain. The group comprised 15 schizophrenic patients with persistent tardive dyskinesia and 21 in-patient schizophrenic controls who were group-matched for demographic variables.

RESULTS

The dyskinetic subjects had a significantly larger left caudate nucleus and tended to have a larger right caudate nucleus than the controls. There were no differences between the groups on any of the measures of cerebral atrophy.

CONCLUSIONS

The findings can be understood within the context of models of neostriatal function. It is possible that a larger caudate nucleus could be used to identify patients at risk of developing tardive dyskinesia.

Handedness and the risk of tardive dyskinesia

Previous results from five cross-sectional studies are conflicting about the relationship between hand preference and tardive dyskinesia (TD): two report a greater TD prevalence in left handers, and three report a greater prevalence in right handers. To help resolve these inconsistencies, the handedness-TD association was assessed in the Yale TD Study, a large prospective cohort investigation of outpatients maintained with neuroleptics. A consistent monotonic association was observed between the handedness score and TD incidence (p = 0.009). The estimated rate ratio, comparing left and mixed handers with pure right handers, adjusted for confounders, was 0.25 (95% confidence interval = 0.09, 0.70). The handedness effect (higher TD rate in right handers) was stronger for subjects with fewer negative symptoms, and it was stronger for men than for women. Although the specific biological mechanisms are unclear, these findings may reflect cerebral laterality in the pathophysiology of psychiatric disorders, possibly in combination with asymmetrical action of neuroleptic exposure.

Basal ganglia T2 relaxation times in schizophrenia: a quantitative magnetic resonance imaging study in relation to tardive dyskinesia

Transverse, or spin-spin, relaxation times (T2) from magnetic resonance images of basal ganglia structures were compared between control subjects and patients with schizophrenia, who were subdivided on the basis of the presence or absence of tardive dyskinesia. As a group, schizophrenic patients showed evidence of somewhat more prolonged T2 relaxation times in the right putamen and globus pallidus than did control subjects; there were no significant correlations between hemispheric T2 values and corresponding volumes of the lateral ventricles. Overall, there was little difference in T2 values between patients with and without tardive dyskinesia. These data extend the range of evidence for basal ganglia dysfunction in schizophrenia, but they do not support earlier reports of prominent T2 changes associated with tardive dyskinesia.

Tardive dyskinesia in schizophrenia. Relationship to minor physical anomalies, frontal lobe dysfunction and cerebral structure on magnetic resonance imaging

BACKGROUND

It was hypothesised that schizophrenic patients with tardive dyskinesia show an excess of neurodevelopmental disturbance, particularly minor physical anomalies, in association with cognitive dysfunction and abnormalities of cerebral structure.

METHOD

Forty-seven out-patients with a DSM-III diagnosis of schizophrenia were examined for tardive dyskinesia using the Abnormal Involuntary Movement Scale; they were examined also for minor physical anomalies and neuropsychological test performance. Cortical atrophy, signal hyperintensities and lateral ventricular volume were determined on magnetic resonance imaging.

RESULTS

Patients with and without tardive dyskinesia could not be distinguished by age, gender distribution or a number of clinical measures; however, patients with tardive dyskinesia sorted fewer categories on the Wisconsin Card Sorting Test (P = 0.04). Cerebral structure in patients with and without tardive dyskinesia could not be distinguished on magnetic resonance imaging but those with dyskinesia, all of whom showed involvement of the orofacial region, showed more evident minor physical anomalies of the head relative to those of the periphery (P = 0.02).

CONCLUSIONS

Tardive orofacial dyskinesia in schizophrenia appears to be associated particularly with poorer frontal lobe function, while predominance of craniofacial dysmorphogenesis may constitute a vulnerability factor that is related to the early origins of the disease process.

Schizophrenics with small P300: a subgroup with a neurodevelopmental disturbance and a high risk for tardive dyskinesia?

Schizophrenics with a neurodevelopmental disturbance resulting in micro- and macroanatomical cortical abnormalities are supposed to form a subgroup clinically characterized by low premorbid adjustment, early onset, incomplete remission, poor outcome, male predominance and high risk for tardive dyskinesia. A small amplitude of the event-related P3 (P300) potential could be a marker of this subgroup, because the cortical neurons and their orderly laminar arrangement are crucial for the electrogenesis of P3. In a 2-year follow-up study, auditory evoked P3 was recorded in 89 stabilized schizophrenic outpatients. Patients who developed tardive dyskinesia during the follow-up had smaller P3 than matched controls. Furthermore, a small P3 was associated with low premorbid adjustment, pronounced residual symptoms, low relapse rate, and male predominance. These findings indicate that schizophrenic patients with a reduced P3 have a higher risk of developing tardive dyskinesia and correspond clinically to a schizophrenic subgroup with a supposedly neurodevelopmental disturbance.

Basal ganglia abnormalities in tardive dyskinesia. Possible relationship with duration of neuroleptic treatment

The purpose of the present study was to investigate CT abnormalities in tardive dyskinesia (TD) and to search for possible relationships with clinical data. A group of 30 psychotic patients (15 schizophrenic and 15 affective disorder) with TD was compared to a matched group of 30 psychiatric patients without TD and a matched group of 30 healthy controls. CT data were analyzed using two multivariate statistical methods [multidimensional scaling (MDS) and step-wise discriminant analysis]. MDS clearly separated both TD and non-TD groups from the healthy control group on the basis of CT parameters. Caudate left area reduction and left temporal sulci enlargement were the most important parameters that discriminated TD from non-TD patients. Only in TD-patients did caudate left area reduction and left temporal sulci enlargement correlate significantly with cumulative duration of psychiatric hospitalizations. The data of the present study support the findings of structural abnormalities in the caudate nucleus and in the temporal lobe of patients with TD. These abnormalities were especially marked in the left hemisphere. It is assumed that some factor related to longer psychiatric hospital treatment (e.g. neuroleptic intake) could account for these abnormalities.

Loss of striatal cholinergic neurons as a basis for tardive and L-dopa-induced dyskinesias, neuroleptic-induced supersensitivity psychosis and refractory schizophrenia

In the first section of this paper several aspects of tardive dyskinesia (TD) (clinical, epidemiological, pharmacological) are reviewed. We propose that this syndrome is not the consequence of dopamine receptor proliferation, but results from damage or degeneration of striatal cholinergic interneurons. We suggest that this cellular damage is caused by prolonged overactivation of these neurons, which occurs when they are released from dopaminergic inhibition following neuroleptic administration. Overactivity of central cholinergic systems during akinetic and motor retarded depression could be a contributory cause. The predisposition to L-DOPA-induced peak-dose dyskinesia in Parkinson's disease may depend on the same type of striatal neuronal loss. In the second part of the paper, the subject of supersensitivity psychosis and drug-resistant schizophrenia is reviewed. These two syndromes, are commonly associated with TD, have similar predisposing factors and pharmacology to TD, and are potentially persistent. We suggest that these conditions also result from degeneration of cholinergic striatal interneurons following chronic neuroleptic administration. The efficacy of clozapine for such treatment-refractory psychoses is explained in terms of its blockade of D-1 dopamine receptors. Other drugs effective against refractory psychoses (e.g. risperidone) are predicted to reduce activation at D-1 receptors.

Three-year follow-up of older schizophrenics: extrapyramidal syndromes, psychiatric symptoms, and ventricular brain ratio

Longitudinal evaluation of psychiatric patients often yields information that cross-sectional study does not. We previously examined 31 older (age greater than 55) chronic schizophrenics for prevalence of extrapyramidal side effects, severity of psychiatric symptoms, and ventricular brain ratio (VBR). We reexamined 22 of these patients after 2-4 years. Tardive dyskinesia (TD) and drug-induced parkinsonism (DIP) were common (mean prevalences were 52% and 62%, respectively) and often occurred together (38%). The overall prevalences of the disorders did not change significantly with time, although there was some individual fluctuation in diagnosis. Severity of TD was constant, but severity of DIP decreased, probably because neuroleptic doses were significantly decreased. Magnitude of DIP was positively correlated with VBR and severity of negative symptoms of schizophrenia. The correlation of DIP and negative symptoms occurred primarily because of the similarity between masked facies and blunted affect. VBR did not change over the follow-up period. Negative symptoms of schizophrenia were prevalent, moderately severe, and quite stable over time in this cohort. Positive symptoms were less severe but highly variable between examinations.