Neurological complications of psychiatric drugs: clinical features and management

Genome-wide association study of antipsychotic-induced parkinsonism severity among schizophrenia patients

RATIONALE

Antipsychotic-induced parkinsonism (AIP) is a severe adverse affect of neuroleptic treatment. Interindividual heterogeneity in AIP development and severity is associated with risk factors such as antipsychotic drug type, old age, and female gender. There is evidence for genetic predisposition to develop AIP but the variants that confer susceptibility or protection are mostly unknown.

OBJECTIVE

To identify genes related to AIP susceptibility, we performed a pharmacogenomic genome-wide association study (GWAS) for AIP severity.

METHODS

Three hundred ninety-seven American schizophrenia patients who participated in the Clinical Antipsychotic Trials of Intervention Effectiveness (CATIE)-GWAS project were included in our analysis. Patients had been randomized to treatment with antipsychotic monotherapy for periods ranging from 2 weeks to 18 months during phase 1 of the CATIE trial. They were regularly assessed for AIP severity using the modified Simpson-Angus Scale (SAS). For statistical analysis, patients were dichotomized as cases (average SAS mean global score > 0.3 during CATIE phase 1, N = 199) or controls (average SAS mean global score 0, N = 198).

RESULTS

Using logistic regression and controlling for population stratification, age, gender, SAS score at baseline, and concomitant use of anticholinergic drugs, we identified several single-nucleotide polymorphisms associated with AIP severity. Although none reached the GWAS significance level of P < 4.2 x 10(-7), some promising candidate genes for further research on genetic predisposition to AIP were identified including EPF1, NOVA1, and FIGN.

CONCLUSIONS

Our finding may contribute to understanding of the pathophysiology of AIP as well as to a priori identification of patients vulnerable for development of AIP.

Inhibition of recombinant Ca(v)3.1 (alpha(1G)) T-type calcium channels by the antipsychotic drug clozapine

Low voltage-activated T-type calcium channels are involved in the regulation of the neuronal excitability, and could be subject to many antipsychotic drugs. The effects of clozapine, an atypical antipsychotic drug, on recombinant Ca(v)3.1 T-type calcium channels heterologously expressed in human embryonic kidney 293 cells were examined using whole-cell patch-clamp recordings. At a standard holding potential of -100 mV, clozapine inhibited Ca(v)3.1 currents with an IC(50) value of 23.7+/-1.3 microM in a use-dependent manner. However, 10 microM clozapine inhibited more than 50% of the Ca(v)3.1 currents in recordings at a more physiologically relevant holding potential of -75 mV. Clozapine caused a significant hyperpolarizing shift in the steady-state inactivation curve of the Ca(v)3.1 channels, which is presumably the main mechanism accounting for the inhibition of the Ca(v)3.1 currents. In addition, clozapine slowed Ca(v)3.1 deactivation and inactivation kinetics but not activation kinetics. Clozapine-induced changes in deactivation and inactivation rates of the Ca(v)3.1 channel gating would likely facilitate calcium influx via Ca(v)3.1 T-type calcium channels. Thus, clozapine may exert its therapeutic and/or side effects by altering cell's excitability and firing properties through actions on T-type calcium channels.

Non-motor cognitive-perceptual dysfunction associated with drug-induced parkinsonism

OBJECTIVE

The purpose of the present study was to examine the relationship between drug-induced parkinsonism (DIP) and subjective non-motor cognitive impairments in schizophrenia by performing comprehensive assessments of extrapyramidal side effects (EPS) and the subjective cognitive-perceptual functioning.

METHODS

Ninety-one outpatients with schizophrenia were evaluated for DIP and other EPS. Subjective cognitive-perceptual dysfunction was comprehensively assessed using the Frankfurt Complaint Questionnaire (FCQ). To examine the association between DIP and non-motor cognitive-perceptual dysfunction, Pearson's partial correlation analysis was performed between the FCQ scores and the severity of DIP, controlling for relevant variables.

RESULTS

The analysis revealed that the severity of DIP had a significant correlation with the total FCQ score (p < 0.05). In phenomenological subscales, the severity of DIP showed significant correlations with "deterioration of discrimination," "psychomotor disorder," "perceptual disorder," "cognitive floating," and "automatic behavior disorder" (p < 0.05).

CONCLUSIONS

The results of our study suggest that DIP is significantly associated with a wide range of subjective non-motor cognitive impairments. Clinicians should be careful of the appearance of DIP and the associated non-motor cognitive-perceptual symptoms, which may cause considerable distress and reduce the quality of life in an already vulnerable group of patients.

Movement disorders

Abnormal involuntary movements are major features of a large group of neurologic disorders, some of which are neurodegenerative and pose a significant diagnostic and treatment challenge to treating physicians. This article presents a concise review of clinical features, pathogenesis, epidemiology, and management of seven of the most common movement disorders encountered in a primary care clinic routinely. The disorders discussed are Parkinson disease, essential tremor, restless legs syndrome, Huntington disease, drug-induced movement disorder, Wilson disease, and Tourette syndrome.

The efficacy of nurse implemented non-pharmacological strategies for the symptom management of agitation in persons with advanced dementia living in residential aged care facilities: a systematic review

AIM

Agitation is a common symptom of dementia which becomes exacerbated in the advanced stages of the disease. The negative effects of this symptom are numerous and often result in institutionalisation. Given it is the registered nurse, with the cooperation of the enrolled nurse/ assistant in nursing, who provide the majority of face-to-face care in residential aged care facilities, there is a clear need to identify effective management strategies for agitated behaviours which nursing staff can easily access and implement.This review identifies the best available evidence regarding the efficacy of nurse implemented non-pharmacological strategies for the symptom management of agitation in persons with advanced dementia living in residential aged care facilities METHOD: A systematic literature search of MEDLINE, CINAHL, PsycINFO, Cochrane Library, SCOPUS, EMBASE, and AgeLine databases was undertaken. Additionally, the reference lists of relevant papers were examined for additional trials.This review considered any English language randomised trial that investigated strategies implemented by a nurse for the symptom management of agitation in persons with advanced dementia living in residential aged care facilities. Outcomes measured included frequency and severity of agitation.

RESULTS

Seven trials were included in this review. Five of the seven strategies investigated were shown to be effective in the symptom management of agitation when compared to alternate strategies. Effective strategies include: behavioural therapy, balancing arousal states, therapeutic touch, multi-sensory stimulation and person-centred bathing.

CONCLUSIONS

The heterogeneity of the included trials made it difficult to draw definitive conclusion. However, the results of this systematic review reveal that some non-pharmacological strategies are effective when implemented by a nurse for the symptom management of agitation in pesons with advanced dementia living in residential aged care facilities. Despite this finding, there is currently insufficient evidence to develop practice guidelines.

Medical complications of psychiatric treatment

Psychiatric medications are frequently an essential component of care for critically ill patients. Their use may lead to medical complications, however, as a result of (1) direct toxicity from psychotropic medications, (2) drug-drug interactions, or (3) intoxication or withdrawal states. These complications may be a nuisance (eg, dry mouth and nausea) or serious and life-threatening (eg, neuroleptic malignant syndrome and cardiac arrhythmias). This article addresses the most important medical complications (organized by organ systems) of psychiatric treatment.

Current awareness: Pharmacoepidemiology and drug safety

In order to keep subscribers up‐to‐date with the latest developments in their field, John Wiley & Sons are providing a current awareness service in each issue of the journal. The bibliography contains newly published material in the field of pharmacoepidemiology and drug safety. Each bibliography is divided into 20 sections: 1 Reviews; 2 General; 3 Anti‐infective Agents; 4 Cardiovascular System Agents; 5 CNS Depressive Agents; 6 Non‐steroidal Anti‐inflammatory Agents; 7 CNS Agents; 8 Anti‐neoplastic Agents; 9 Haematological Agents; 10 Neuroregulator‐Blocking Agents; 11 Dermatological Agents; 12 Immunosuppressive Agents; 13 Autonomic Agents; 14 Respiratory System Agents; 15 Neuromuscular Agents; 16 Reproductive System Agents; 17 Gastrointestinal System Agents; 18 Anti‐inflammatory Agents ‐ Steroidal; 19 Teratogens/fetal exposure; 20 Others. Within each section, articles are listed in alphabetical order with respect to author. If, in the preceding period, no publications are located relevant to any one of these headings, that section will be omitted.

Tardive parkinsonism in a bipolar patient: post-mortem examination supports a physiological rather than pathological dysfunction

We describe a case of tardive parkinsonism in the setting of bipolar syndrome, and we offer pathological confirmation that idiopathic Parkinson disease was not the underlying etiology. A 74-year-old Hispanic woman with a history of bipolar disease was noted to have oro-buccal-lingual chorea and parkinsonian symptoms such as resting tremor, rigidity, bradykinesia, and gait disorder persisting several months after neuroleptic discontinuation. She had minor improvement in ambulation with levodopa treatment, and she significantly improved in ambulation only during her manic states. Examination of the subject's post-mortem brain revealed no explicit evidence of degeneration in substantia nigra or other brainstem centers, and no nigral or cortical Lewy bodies were present. Glial cytoplasmic inclusions (characteristic of multiple systems atrophy) and globose neurofibrillary tangles (seen in progressive supranuclear palsy) were not seen either. This patient's presentation was most consistent with neuroleptic-induced parkinsonism and tardive dyskinesia; the etiology was likely related to previous neuroleptic exposure.