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Biomedical subjects

B N Gangadhar

Publications and source records attributed to B N Gangadhar.

At least 19 recordsLinked to original sources
PubMed1999

Motor seizure monitoring during electroconvulsive therapy.

BACKGROUND: The occurrence of a seizure during electroconvulsive therapy (ECT) should be confirmed. Most clinicians use motor seizure monitoring alone and recent guidelines have not considered electroencephalogram (EEG) monitoring mandatory. AIMS: To examine the potential pitfalls of motor seizure monitoring. METHOD: Consenting consecutive patients (n = 232) were prospectively studied at the first ECT session using both motor and EEG seizure monitoring. It was ensured (by titration) that all the patients had an adequate EEG seizure. Adequate and prolonged seizures were defined according to the latest recommendations of the Royal College of Psychiatrists. RESULTS: Motor seizure was inadequate in 15 (7%) of patients. EEG seizure was prolonged in 38 (16%) of patients. Fifteen patients (39%) did not have a prolonged motor seizure. Motor seizure correlated well (r = 0.8, P < 0.001) with EEG seizure when the latter was adequate, but not when prolonged (r = 0.12, P > 0.5). CONCLUSIONS: Motor seizure monitoring without EEG is undependable. The study provides a rational basis for the Royal College of Psychiatrists' definition of prolonged EEG seizure.

Adolescent↗
PubMed1999

An intrasubject comparison of two doses of succinylcholine in modified electroconvulsive therapy.

UNLABELLED: The electroconvulsive therapy (ECT) guideline of the Royal College of Psychiatrists recommends a 0.5 mg/kg of succinylcholine for ECT modification. Our clinical experience suggests that this dose is insufficient for Indian patients. The dose recommended by the Royal College of Psychiatrists (0.5 mg/kg) and a larger dose (1 mg/kg) were compared in 50 patients referred for ECT. In one ECT session, patients were equally randomized to receive one of the two doses and in the next session they were switched to the other dose. The extent of motor seizure modification was rated on a five-point scale by two independent raters who were blinded to the succinylcholine dose. The interrater reliability was good (K = 0.85). "Poor" seizure modification occurred in 48% and 12% of patients with the 0.5 and 1 mg/kg doses, respectively. Of the 24 patients who had poor modification with 0.5 mg/kg, 20 had "good" modification in the session with 1 mg/kg (P < 0.001). A small delay (mean = 55 s) occurred in time to recover from the respiratory paralysis with the 1 mg/kg dose of succinylcholine. No patient, however, had prolonged apnea requiring special measures. We recommend 1 mg/kg of succinylcholine dose be used in the first ECT session. For subsequent sessions, the dose may be altered, depending on the response for optimal motor seizure modification. IMPLICATIONS: The dose of muscle relaxant (succinylcholine) recommended in modified electroconvulsive therapy is not based on empirical research. In the same patients (n = 50), two doses-0.5 mg/kg and 1 mg/kg-were compared during different electroconvulsive therapy sessions. The larger dose was more effective in modifying the peripheral convulsion.

Adult↗
PubMed1998

Heart rate variability as an index of cue reactivity in alcoholics.

BACKGROUND: Autonomic responses follow exposure to conditioned stimuli such as contextual factors associated with alcohol ingestion. Heart rate variability is under autonomic control and may be a measure of such response. METHODS: Twenty alcoholics and 23 matched social drinkers (all male) were exposed to a neutral cue and then an alcohol cue in identical settings, during which the electrocardiogram of these subjects was recorded. Time and frequency domain parameters of heart rate variability (HRV) were computed by a blind rater. RESULTS: Coefficient of variation of R-R intervals and absolute powers of HRV spectrum (in frequency bands 0.05-0.15 Hz and 0.01-0.05 Hz) following alcohol cue were significantly higher in alcoholics than social drinkers. The mean heart rate (MHR) failed to reflect this difference. CONCLUSIONS: HRV paradigm appears more sensitive than MHR to measure cue reactivity.

Adult↗
PubMed1998

Haloperidol-induced extrapyramidal reaction: lack of protective effect by vitamin E.

Haloperidol treatment has been shown to produce oxidative stress in patients with acute psychosis. Oxidative stress has also been implicated in the extrapyramidal symptoms (EPS) produced by haloperidol. Supporting the oxidative stress hypothesis, vitamin E (antioxidant) has demonstrated therapeutic efficacy in idiopathic parkinsonism. The prophylactic efficacy of vitamin E (antioxidant) on haloperidol-induced EPS was examined in a randomized controlled trial. The sample consisted of 24 acute psychotic patients hospitalized for a 2-week trial. All patients received oral haloperidol 10 mg/day. The sample was equally randomized to receive either haloperidol alone or haloperidol + vitamin E (3200 IU/day). EPS was rated at recruitment, both live and with video records, and on days 3, 7, 10 and 14. Psychopathology was rated at recruitment and weekly thereafter. Vitamin E had no prophylactic effect on drug-induced EPS, though it did not interfere with the therapeutic efficacy of haloperidol.

Adolescent↗
PubMed1998

P300 amplitude and antidepressant response to Sudarshan Kriya Yoga (SKY).

BACKGROUND: There is evidence that Sudarshan Kriya Yoga (SKY) has significant antidepressant effects. OBJECTIVE: The present study examined whether pretreatment P300 ERP amplitude predicts antidepressant response to SKY. METHODS: Consenting, drug-free depressed patients (n = 30; dysthymics, 15, melancholics, 15) who received SKY as the sole treatment were assessed clinically at pretreatment, 1 month and 3 months. Auditory P300 was recorded before treatment. RESULTS: Twenty-two patients responded favourably to SKY. The pretreatment P300 amplitude neither distinguished responders and non-responders nor was associated with differential rates of response. DISCUSSION: It is concluded that SKY therapy is uniformly effective regardless of the pretreatment P300 amplitude.

Adult↗
PubMed1998

Atropine premedication and the cardiovascular response to electroconvulsive therapy.

A report by the Royal College of Psychiatrists recommended avoiding atropine premedication during electroconvulsive therapy (ECT). We have examined the cardiovascular effects of ECT with or without atropine premedication. Consenting patients (n = 30) were allocated randomly before their third ECT session to receive atropine or no premedication. The rate pressure product (RPP) was recorded before anaesthesia, before ECT stimulus and at 1-min intervals thereafter for 5 min. Patients who did not receive atropine had significantly lower RPP values after all stimulus recordings. Administration of atropine or not explained 32% of the variance of summated RPP after the stimulus. There was no clinically significant bradyarrhythmia in those who did not receive atropine. Our findings support the recommendation of the Royal College of Psychiatrists. The study suggests that when threshold determination is not needed, avoiding atropine effectively contains potentially harmful cardiovascular responses.

Adjuvants, Anesthesia↗
PubMed1998

Sex difference in age at onset of schizophrenia: discrepant findings from India.

Consecutive male (n=100) and female (n=100) DSM-IV schizophrenics newly registered for treatment in a large psychiatric hospital were examined with regard to age at onset of the first psychotic symptom. Age at onset of the first psychotic symptom did not differ between the sexes regardless of whether schizophrenia was diagnosed by DSM-IV or by several alternative systems. Age at onset defined by other criteria, namely age at first contact with a physician, and age at first admission for psychiatric care, also did not show any differences between the sexes. Survival analysis of subjects having a documented date of birth revealed a female preponderance at younger ages. A higher positive symptom score predicted older age at onset of the first psychotic symptom in the total sample. These findings call into question the universality of the traditional view of a younger age at onset of schizophrenia among males. Tentative neurodevelopmental and cultural explanations are presented to explain why there is no sex difference in age at onset of schizophrenia in India.

Adolescent↗
PubMed1998

Once vs. three times weekly ECT in melancholia: a randomized controlled trial.

Once weekly and three times weekly schedules of ECT, each at two stimulus dose levels (high and low), were compared for therapeutic efficacy in melancholia. Three times weekly ECTs were more efficacious than once weekly ECTs. A high stimulus dose did not enhance the efficacy of once weekly ECTs. However, the patients who remitted did so over a comparable time-course regardless of the ECT schedule. Although three times weekly ECTs are superior, 55% of patients responded to once weekly ECTs. There is therefore a need for research to identify the patients for whom once weekly ECT may be sufficient.

Adult↗
PubMed1998

EEG seizure in bilateral ECT is different between low and high stimulus doses.

Melancholic depressive patients referred for ECT were randomized to receive either low dose (n = 20) or high dose (n = 20) stimulus applied bifrontotemporally. The two stimulus groups were comparable on the clinical variables. The EEG seizure was recorded on two channels (right and left frontal), digitized, coded and analyzed offline without knowledge of ECT parameters. EEG seizure was of comparable duration in the two stimulus (high dose and low dose) groups. A new composite measure, Strength-Symmetry-Index (SSI), based on strength and symmetry of seizure EEG was computed using fractal geometry. The SSI of the early-seizure was higher in the high dose than in the low dose ECT group. In a stepwise, logistic regression model, this variable contributed to 65% with correct classification of high dose and low dose ECT seizures.

Adult↗
PubMed1998

Acute post-ECT cardiovascular response: a comparison of threshold right unilateral and bilateral ECT.

The effect of electrode placement on cardiovascular responses was studied. Rate pressure product and diastolic blood pressure before anesthesia and 30 s after electroconvulsive therapy (ECT) seizure were recorded. Recordings were made at the first (threshold ECT) session in 124 bilateral ECT (BLECT) and 95 unilateral ECT (ULECT) consenting patients. Postictal rate pressure product (RPP) was significantly higher after BLECT than ULECT. Mean increase in RPP from pre- to postictal phase was 31% in the former. The corresponding change with ULECT (20%) was significantly smaller. In the stepwise, multiple regression model, pre-ECT RPP, age, and stimulus laterality significantly contributed to postictal RPP. No cardiovascular complications occurred in any of the 219 ECT sessions.

Adult↗
PubMed1998

Formula method for stimulus setting in bilateral electroconvulsive therapy: relevance of age.

Seizure thresholds were determined by titration in consecutive electroconvulsive therapy (ECT) patients at the first (n = 146) and sixth (N = 83) ECT sessions. Equations to predict the threshold at the first and sixth ECT were computed from these data using a stepwise linear regression model. These equations were tested prospectively at the first ECT (n = 48) and sixth ECT (n = 26) sessions. Stimulus dose derived from the corresponding equations yielded adequate seizure (successful) in 82% and 84% of patients, respectively. Predictions based on age alone (disregarding two other significant variables--illness severity and inion-nasion distance) were estimated at these two ECT sessions. This would not appreciably compromise the success rate. The "formula" method using age alone may therefore be used in routine clinical practice.

Adolescent↗
PubMed1997

Gender but not stimulus parameters influence prolactin response to electroconvulsive therapy.

The post-ictal prolactin (PRL) response represents one of the most consistent findings of electroconvulsive therapy (ECT), but correlates variably with the gender of the patient, ECT stimulus waveform, dose and electrode placement. Forty patients with endogenous depression (29 drug-naive) received either high-energy (240 mC) or low-energy (60 mC) bilateral brief-pulse ECT once or three times a week. The PRL and growth hormone (GH) levels were estimated using double antibody radioimmunoassay. The average post-ECT PRL levels differed significantly from the pre-ECT levels, with a seven- to nine-fold increase in PRL at each week of treatment. No such difference was observed in the GH levels. All patients showed an increase in PRL levels, whereas 42% failed to show an increase in GH levels. The delta PRL response (difference between post-ECT and pre-ECT serum hormone levels) was not significantly different between the drug-naive and medicated patients nor between the high-energy and low-energy groups at first ECT. Similarly, no difference was observed between the once-weekly and thrice-weekly groups at the third week of ECT. At each week of treatment, the delta PRL was significantly higher in females than in males, unlike the GH response. Electroencephalographic (EEG) seizure duration did not correlate with either delta PRL or delta GH at first ECT and third week ECT. Apart from gender, none of the variables, such as age, baseline severity of illness, presence of psychotic symptoms, drug-naive status, stimulus dose, seizure duration, seizure strength, pattern and symmetry, frequency of ECT and degree of improvement predicted the delta PRL response. Neither stimulus energy nor frequency of ECT had a significant effect on PRL response. Gender differences in PRL response to ECT merit further investigations.

Adult↗
PubMed1997

More on ECT.

Explore the source record for details and available documents.

Adolescent↗
PubMed1997

Strength Symmetry Index: a measure of seizure adequacy in ECT.

Seizure electroencephalography (EEG) was recorded from two channels--right (Rt) and left (Lt)--during bilateral electroconvulsive therapy (ECT) (n = 12) and unilateral ECT (n = 12). The EEG was also acquired into a microcomputer and was analyzed without knowledge of the clinical details. EEG recordings of both ECT procedures yielded seizures of comparable duration. The Strength Symmetry Index (SSI) was computed from the early- and midseizure phases using the fractal dimension of the EEG. The seizures of unilateral ECT were characterized by significantly smaller SSI in both phases. More unilateral than bilateral ECT seizures had a smaller than median SSI in both phases. The seizures also differed on other measures as reported in the literature. The findings indicate that SSI may be a potential measure of seizure adequacy that remains to be validated in future research.

Cerebral Cortex↗
PubMed1996

"Normal' P300 amplitude predicts rapid response to ECT in melancholia.

Consenting melancholic depressives (n = 17) were treated with bilateral ECT under anaesthesia. All patients except two were antidepressant-naive. The auditory P300 event-related potential (ERP) was recorded before and after the ECT course. The latency of P300 in depressives before treatment did not differ from controls, but the amplitude was smaller than in matched controls (n = 15). The P300 amplitude was larger in depressives who had rapid response than in the rest. Rapid responders did not differ from controls on P300 amplitude before treatment. Hence it is suggested that "Normal' P300 predicts rapid therapeutic response to ECT in melancholia.

Adult↗