Biomedical subjects

P S Sachdev

Publications and source records attributed to P S Sachdev.

At least 37 records · Page 2Linked to original sources

PubMed2000

The current status of tardive dyskinesia.

OBJECTIVE: This paper aims to provide an overview of the current knowledge on neuroleptic-induced tardive dyskinesia (TD) in relation to its clinical features, risk factors, pathophysiology and management. METHOD: The published literature was selectively reviewed and assessed. RESULTS: Tardive diskinesia is a common neurological side-effect of neuroleptic medication, the cumulative incidence of which increases with increasing duration of treatment. Its clinical manifestations are diverse and subsyndromes have been described. Many risk factors for TD are now recognised, but increasing age remains pre-eminent as a risk factor. The pathophysiology of TD is not completely understood. Of the neurotransmitter hypotheses, the dopamine receptor supersensitivity hypothesis and the gamma-aminobutyric acid insufficiency hypothesis are the main contenders. There is increasing recognition that TD may in fact be caused by neuroleptic-induced neuronal toxicity through free radical and excitotoxic mechanisms. The occurrence of spontaneous dyskinesias in schizophrenic patients and even healthy subjects suggests that neuroleptics act on a substratum of vulnerability to dyskinesia. As no effective treatment for TD is available, the primary emphasis is on prevention. Many drugs can be tried to reduce symptoms in established cases. The increasing use of atypical neuroleptics has raised the possibility of a lower incidence of TD in the future. CONCLUSIONS: After four decades of clinical recognition, the pathophysiology of TD is still not understood and no effective treatment is available. Its prevention with the optimal usage of currently available drugs and regular monitoring of patients on long-term neuroleptic treatment remain the best strategies to reduce its impact.

Age Factors↗

PubMed1999

Differentiation of vascular dementia from AD on neuropsychological tests.

BACKGROUND: The concept of vascular dementia (VaD) is currently in a state of evolution. Memory impairment is emphasized as a primary criterion, reflecting the influence of AD on the concept of dementia. We have systematically reviewed whether the nature of neuropsychological dysfunction is distinct in AD and VaD, and whether similar defining criteria for the concept of dementia in both disorders can be supported. METHODS: We searched five bibliographic databases (Medline, Biological Abstracts, EMBASE, PsychINFO, PsychLIT) for research articles in which VaD and AD had been compared using neuropsychological tests and that met criteria for scientific merit. RESULTS: Of the 45 studies, 18 were excluded because of inadequacies, and the remaining 27 were analyzed. There were a number of similarities of dysfunction between VaD and AD. However, when matched for age, education, and severity of dementia, VaD patients had relatively superior function in verbal long-term memory and more impairment in frontal executive functioning compared with AD patients. Interpretation of the results is limited by uncertainty in diagnostic criteria for VaD, possible inclusion bias due to use of clinical diagnosis alone, possible overlap of AD and VaD, and the methodologic shortcomings of some studies. CONCLUSIONS: The neuropsychological differentiation of VaD from AD was consistent with the different neuroimaging findings in the two disorders, and argues for differential criteria for the definition of the syndromes. The simple application of Alzheimer's dementia criteria to VaD, with the inclusion of cerebrovascular disease etiology, may not be sufficient to capture the uniqueness of VaD.

Alzheimer Disease↗

PubMed1999

Vascular dementia: diagnosis, management and possible prevention.

There has been a recent upsurge of interest in the clinical features of and risk factors for vascular dementia, and consensus is emerging on its diagnostic characteristics. We discuss these features and risk factors and the main intervention strategies, both for treatment and prevention.

Dementia, Vascular↗

PubMed1999

Mid-sagittal anatomy in late-onset schizophrenia.

BACKGROUND: Of the midline brain structures, abnormalities have been demonstrated in the corpus callosum and cerebellum in young schizophrenic patients. Whether similar abnormalities are also present in late-onset schizophrenia (LOS) is not known. METHODS: The mid-sagittal cross-sectional areas of brain regions, in particular the corpus callosum and cerebellum, on magnetic resonance imaging were examined in a group of patients with late-onset schizophrenia (N = 25) and contrasted with two comparison groups - early-onset schizophrenia (EOS) (N = 24) and healthy volunteers (NC) (N = 30) matched for age and gender. RESULTS: While the mean corpus callosum area in the LOS group was smaller than in the EOS (by 10.2%) and NC (by 6.2%) groups, the three groups did not differ statistically in the corpus callosum area or the corpus callosum to cerebrum ratios. The cross-sectional cerebellar areas or the cerebellum: cerebrum ratios also did not differ across the groups. The brainstem was smaller in the schizophrenic groups because of smaller cross-sectional areas of the pons, a statistically significant difference which could not be accounted for by any gross lesions on visual inspection. CONCLUSION: We found no abnormality in the mid-sagittal area of the corpus callosum and cerebellum in our early- or late-onset schizophrenia subjects. The significance of the finding of a smaller pontine cross-sectional area is unclear and speculation on it awaits independent replication using a volumetric measure.

Age Factors↗

PubMed1999

Electroconvulsive treatment of neuroleptic malignant syndrome: a review and report of cases.

OBJECTIVE: Neuroleptic malignant syndrome (NMS) is a potentially lethal adverse effect of neuroleptic medication, with no satisfactory treatment currently available. Electroconvulsive therapy (ECT) has been anecdotally reported to be effective in its treatment. We review 45 published case reports of ECT for NMS and describe nine new cases, to examine its effectiveness, the likelihood of adverse reactions, and the theoretical implications of such treatment. METHOD: The authors used Medline to identify reports in the English literature where ECT was used in cases of suspected NMS. In addition, the charts of patients referred to the second author for treatment of NMS were reviewed and cases in which ECT used were identified. RESULTS: The case reports suggest that ECT is effective in many individuals with NMS, even when drug therapy has failed. The response is usually apparent after a few treatments, generally up to six. The response is not predictable on the basis of age, gender, psychiatric diagnosis or any particular feature of NMS including catatonia. Electroconvulsive therapy is a relatively safe treatment in NMS, although the risk of cardiovascular complications should be considered. Malignant hyperthermia due to the anaesthesia associated with ECT has not been reported in patients with NMS, and succinylcholine has been used safely with the exception of one report of fever and raised creatine kinase levels and another report of hyperkalemia. CONCLUSIONS: Electroconvulsive therapy is the preferred treatment in severe NMS, cases where the underlying psychiatric diagnosis is psychotic depression or catatonia, and in cases where lethal catatonia cannot be ruled out. The effectiveness of ECT for the treatment of NMS has theoretical implications for the relationship between NMS and catatonia, and the possible pathophysiological mechanisms that underlie these disorders.

Adolescent↗

PubMed1998

Effects of specific dopamine D1 and D2 receptor antagonists and agonists and neuroleptic drugs on emotional defecation in a rat model of akathisia.

An increase in emotional defecation in rats in a well-habituated environment induced by neuroleptic drugs (NDef) has been proposed as a model for neuroleptic-induced akathisia. We examined the effects of dopamine receptor antagonists and agonists on this model. A selective dopamine D1 antagonist (SCH 23390) and a selective D2 antagonist (raclopride) induced increased defecation at higher doses, and demonstrated a synergistic effect at lower doses. Selective D1 (SKF 82958) and D2 (quinpirole) agonists did not have a significant effect on defecation, nor did they reverse the effect of haloperidol. In a further pilot study, we explored the effects of typical and atypical neuroleptics on this model. The haloperidol and risperidone treated rats produced more faecal boli than those treated with clozapine, thioridazine and chlorpromazine, with the former being non-significantly greater than the vehicle-treated group. The results of our studies suggest that NDef is most probably an effect of central dopamine antagonism that is not specific to D1 or D2 receptors, but that the two receptor subtypes have a synergistic effect. It is unlikely to be due to actions of neuroleptics on 5HT2 or alpha1 receptors as has sometimes been suggested. The results have implications for our understanding of the pathogenesis of akathisia.

Akathisia, Drug-Induced↗

PubMed1997

Drugs for the prevention and treatment of Alzheimer's disease.

Alzheimer's disease affects up to 100,000 people in Australia, but pharmacological treatment has only been available in recent years. Currently available drugs provide modest relief of symptoms for varying periods of time but have no proven preventive action against the disease.

Aged↗

PubMed1997

The effects of beta-adrenoceptor antagonists on a rat model of neuroleptic-induced akathisia.

Neuroleptic-induced defecation in rats in a well-habituated environment has been proposed as a model of the subjective component of akathisia. In this study, we examined the effects of two lipophilic beta-adrenoceptor antagonists - the non-selective drug propranolol and the relatively beta1-selective metoprolol - and one non-selective hydrophilic drug nadolol in this model. Young male Wistar rats were randomly assigned to one of eight groups (n = 12 in each group) and treated with haloperidol or vehicle, with or without one of the beta-antagonists. Haloperidol-treated rats had higher bolus counts than vehicle-treated rats, and this increase was significantly reversed by the lipophilic but not the hydrophilic beta-antagonists. This finding is consistent with the reported anti-akathisia effects of these drugs in humans, suggesting that this effect is central in origin and achievable with relatively selective beta1-antagonism. The B-antagonist drugs significantly reduced the cataleptic effect of haloperidol and this effect warrants further examination.

Adrenergic beta-Antagonists↗

PubMed1997

The audiogenic startle reflex in Tourette's syndrome.

The motor response pattern of the audiogenic startle reflex was studied in 15 Tourette's syndrome (TS) patients and 15 normal, age-matched control subjects, using auditory stimuli at 88 and 114 dB. The louder stimuli readily elicited responses in the orbicularis oculi (in all subjects), masseter, sternomastoid, trapezius, deltoid, and biceps (in most subjects) muscles, with a few subjects having responses in the forearm flexors and quadriceps. The TS subjects did not differ from controls in the onset latency, amplitude, and first peak latency of the reflex response in any of the muscles. Rates of habituation in the orbicularis oculi muscle were widely variable across the subjects, and the two groups did not differ overall in the habituation rates. Our study does not support the reports of an abnormal audiogenic startle reflex in TS.

Acoustic Stimulation↗

PubMed1997

A continuing survey of drug-resistant tuberculosis, New York City, April 1994.

BACKGROUND: A 1991 survey showed high levels of drug resistance among tuberculosis patients in New York, NY. As a result, the tuberculosis control program was strengthened, including expanded use of directly observed therapy and improved infection control. METHODS: We collected isolates from every patient in New York City with a positive culture for Mycobacterium tuberculosis during April 1994; results were compared with those in the April 1991 survey. RESULTS: From 1991 to 1994, the number of patients decreased from 466 to 332 patients. The percentage with isolates resistant to 1 or more antituberculosis drugs decreased from 33% to 24% (P < .01); with isolates resistant to at least isoniazid decreased from 26% to 18% (P < .05); and with isolates resistant to both isoniazid and rifampin decreased from 19% to 13% (P < .05). The number of patients with isolates resistant to both isoniazid and rifampin decreased by more than 50%. Among never previously treated patients, the percentage with resistance to 1 or more drugs decreased from 22% in 1991 to 13% in 1994 (P < .05). The number of patients with consistently positive culture results for more than 4 months decreased from 130 to 44. A history of antituberculosis treatment was the strongest predictor of drug resistance (odds ratio = 3.1; P < .001). Human immunodeficiency virus infection was associated with drug resistance among patients who never had been treated for tuberculosis. CONCLUSIONS: Drug-resistant tuberculosis declined significantly in New York City from 1991 to 1994. Measures to control and prevent tuberculosis were associated with a 29% decrease in the proportion of drug resistance and a 52% decrease in the number of patients with multidrug-resistant tuberculosis.

AIDS-Related Opportunistic Infections↗

PubMed1996

Concordance between surface and intra-muscular recordings of facial emg during emotional expression.

Needle and surface EMG recordings were made from the left corrugator supercilii and zygomaticus major muscles, and the skin overlying them, in 12 right-handed normal subjects during imagined and posed sad, happy and angry states. The surface and needle EMG recordings showed good correspondence for the corrugator and zygomaticus major muscles within each individual subject. Considerable inter-subject and inter-emotion variability was, however, observed. The surface to needle concordance was poor when the EMG activity itself was low. While this study does not suggest that specific surface EMG recordings from the face are inappropriate, it provides a note of caution when the activity is low.

Adult↗

PubMed1992

The present status of psychosurgery in Australia and New Zealand.

OBJECTIVES: To assess the extent and nature of psychosurgery currently being performed in Australia and New Zealand, and the present status of legislation regulating its practice. METHODS: Details of current legislation were obtained through inspection of statutes and direct communication with Departments of Health. All full and associate members of the Neurosurgical Society of Australasia were surveyed by postal questionnaire. Ninety-eight neurosurgeons were surveyed, of whom 72 (73%) replied. RESULTS: In the 1980s a mean of nine (SD, 5.9) operations were performed per year; about two were performed per year in the late 1980s. Ninety per cent of these operations were performed at one centre in Sydney. The most common indications were severe and medically intractable depression and obsessive-compulsive disorder. Surgery is now exclusively stereotactic and involves the creation of lesions in the orbitomedial frontal or cingulate tracts or a combination of the two. The nature and type of surgery are comparable to those in other centres in the Western world. Regulatory legislation is in place in most, but not all, States in Australia and in New Zealand. CONCLUSIONS: Further developments of other forms of psychiatric treatments may make psychosurgery, in its present form and at its present level of validation, redundant. If it is to have a resurgence, it would have to be based on a much sounder theoretical premise, and a stronger demonstration of efficacy and predictability of effect.

Adult↗

PubMed1991

Psychoactive drug use in an institution for intellectually handicapped persons.

OBJECTIVE: To study the use of psychoactive drugs for the treatment of long-stay developmentally disabled individuals in an institution in New South Wales. SETTING: Three wards dedicated to the long-term care of developmentally disabled individuals situated on the premises of a large psychiatric hospital. SUBJECTS: All residents (n = 53) of these wards in August 1989. METHOD: All subjects were examined by the author. Charts and medication records were extensively reviewed. Mental retardation was classified by DSM-III-R criteria. Categorisation of problem behaviour was done with the assistance of nurses, who also supplied information on behavioural problems and functional level and completed checklists of self-injurious and stereotypic behaviour. A standardised neurological examination was performed and scales for abnormal involuntary movements completed. RESULTS: The most commonly used drugs were the neuroleptics, with 60.4% of subjects currently receiving one or more neuroleptic drug at relatively large doses. The use of these drugs was not associated with current or past psychiatric illness, but was more closely related with the severity of problem behaviour. Thirty-four per cent of the subjects receiving neuroleptics had dyskinetic movements suggestive of tardive dyskinesia, and 30% had mild tremor. Antidepressant, anxiolytic and sedative drugs were used less commonly. The management of epilepsy was considered to be suboptimal. CONCLUSION: Even though studies over the last two decades have consistently highlighted the problem of overmedication of intellectually handicapped individuals in institutions, the problem does not seem to have been redressed in at least some institutions.

Adolescent↗

PubMed1990

Behavioural factors affecting physical health of the New Zealand Maori.

A major factor in the aetiology of illness is the behaviour of individuals with regard to certain risks and hazards of the environment. The Maori of New Zealand have been shown to be at greater risk of illness and death than their non-Maori counterparts. It is estimated that a significant proportion of this excess morbidity and mortality can be attributed to at least four behavioural factors: smoking, obesity, alcohol use and accidents. This paper examines the inter-cultural differences in these factors, both from a contemporary and an historical perspective. Some of the reasons for the continuation of these adverse patterns of behaviour are explored, in particular the role of psycho-cultural stress. Some possible mechanisms of effecting behavioural change in modern Maori society are discussed.

Accidents↗

PubMed1990

Whakama: culturally determined behaviour in the New Zealand Maori.

Whakama is a psychosocial and behavioural construct in the New Zealand Maori which does not have any exact equivalent in Western societies although shame, self-abasement, feeling inferior, inadequate and with self-doubt, shyness, excessive modesty and withdrawal describe some aspects of the concept. It is an important construct in order to understand the interaction of the Maori with each other and with the Caucasian New Zealander, the behaviour of the Maori in cross-cultural settings, and the clinical presentations of some Maori patients. This paper examines some of the meanings of whakama, its various behavioural manifestations and its possible causes. The clinical relevance to psychiatry is emphasized.

Adaptation, Psychological↗

PubMed1990

Personality development in traditional Maori society and the impact of modernization.

This paper is an attempt to integrate the available research, clinical data and literary information concerning the developmental experiences of the New Zealand Maori. The Maori developmental pattern in the traditional society is compared with that of the Caucasian, mostly Anglo-Saxon, New Zealander (Pakeha), highlighting the contrasting elements while at the same time accommodating considerable overlap between the two postulated developmental patterns. The Maori personality development is seen as being characterized by an indulgent and permissive infancy, a withdrawal of this succorance during childhood, which is characterized by prominent peer-orientation, and a reintegration into adult society during adolescence with gradual maturation of social roles subsequently. The disruption of this pattern as a result of urbanization and Westernization is discussed, along with its adverse consequences. The recent initiatives by the Maori community to preserve the old traditions take the developmental issues into consideration, and although it is too early to judge their success or otherwise, they look quite promising.

Adolescent↗

PubMed1990

Pseudodementia twelve years on.

This paper reports a longitudinal study of 19 patients diagnosed as having pseudodementia more than a decade earlier. In only one patient was the earlier diagnosis changed to definite dementia and, in this patient, there were strong indicators that such a diagnosis should have been made initially. In a second patient, dementia could not be excluded. The remaining patients did not show evidence of a dementing illness and the courses of the illnesses resembled the primary psychiatric disorders responsible for the pseudodementia. The results validate the clinical utility of the term "pseudodementia".

Adult↗

PubMed1990

Intensive neurodiagnostic monitoring in psychiatry.

A series of technological advances have made it possible to closely monitor electrophysiological and behavioural manifestations of episodic clinical events over prolonged periods of time, with the ability to review the records at leisure or to submit them to computer analysis. The more promising techniques are time-locked video/EEG monitoring, cable telemetry, radiotelemetry, ambulatory cassette recording, intensive plasma anti-epileptic drug monitoring and continuous neuropsychological monitoring. The greatest promise of these techniques is for the diagnosis, research and management of epilepsy. For psychiatry, they offer additional help in the differential diagnosis of non-epileptic events from epilepsy, the most important of which are psychogenic seizures and episodes of aggression. This paper discusses the potential role of these techniques in the assessment of non-epileptic events and transient cognitive impairment in clinical psychiatry.

Anticonvulsants↗