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Biomedical subjects

D Talwar

Publications and source records attributed to D Talwar.

At least 37 records · Page 2Linked to original sources
PubMed1997

Modified needle drainage of subretinal fluid for conventional scleral buckling procedures.

This study evaluated the efficacy and safety of a new technique used to drain subretinal fluid (SRF) during conventional scleral buckling procedures. The procedure was performed on 15 patients with primary rhegmatogenous retinal detachment in whom drainage of SRF was necessary during the surgery. It was successful in all but 1 case. The only significant complication was subretinal hemorrhage from the punctured choroid in 1 case, which resolved spontaneously without subsequent complications. This technique reduced the risk of complications during external SRF drainage, especially retinal and vitreous incarceration.

Body Fluids↗
PubMed1997

Evaluation of visual function following argon laser photocoagulation in central serous retinopathy.

The authors of previous studies on the role of photocoagulation for central serous chorioretinopathy (CSR) have based their deductions on the premise that a Snellen visual acuity of 6/6 is the end point of recovery. It is now known that patients with a visual acuity of 6/6 may have defective contrast sensitivity indicative of a visual function deficit. The present study was a prospective, controlled, and randomized evaluation of patients suffering from their first attack of CSR, in which contrast sensitivity was used to determine the effectiveness of argon laser photocoagulation as compared with more conservative treatment. Although long-term studies are necessary, the results of this study showed that while photocoagulation increases the rate of recovery for visual acuity, it is also linked with significant loss and slower recovery of contrast sensitivity.

Adult↗
PubMed1996

Abnormal antioxidant vitamin and carotenoid status in chronic renal failure.

Oxidative modification of plasma lipoproteins increases their atherogenicity. Nutritive antioxidants, including carotenoids, can prevent such lipoperoxidation and may protect against atherosclerosis. Plasma retinol, ascorbate, alpha-tocopherol and four carotenoids (lutein, lycopene, alpha-carotene and beta-carotene) were measured using HPLC in 45 patients with chronic renal failure (CRF) and in 21 controls. Plasma retinol was significantly increased in patients with CRF (conservative therapy mean of 3.7 mumol/l vs. 1.9 mumol/l; p < 0.001). Plasma lycopene was significantly lower in patients with CRF (healthy mean 0.44 mumol/l vs. conservative therapy mean 0.27 mumol/l and haemodialysis mean of 0.17 mumol/l; p < 0.001), a finding that persisted even after adjusting for plasma cholesterol. Low circulating antioxidant lycopene levels may contribute to an already impaired antioxidant defence system in patients with CRF. The process of haemodialysis further compromises antioxidant defences, principally by removing water-soluble ascorbate and urate, but does not appear to affect circulating carotenoid concentrations.

Adult↗
PubMed1996

Assessment of cataract surgery in rural India. Visual acuity outcome.

A socio-epidemiological assessment of what happens to the visual outcome after camp-based intracapsular cataract extraction was conducted in 6 villages and periurban areas in North India. 120 patients (143 eyes) were included in the study. The mean age at cataract extraction was 64.39 (range 33-83 years). 44.7% of the operated eyes obtained a good vision ( > or = 6/18) while 39.9% had low vision (6/24-3/60). The duration since the cataract extraction was seen to influence visual outcome. 70% of the respondents were satisfied with the surgical outcome. 76% of those with unilateral aphakia and 8.3% of those with bilateral aphakia were regularly using spectacles. 58.3% were satisfied with the spectacles. Dissatisfaction was generally due to lack of visual improvement. The major benefits accruing to the patients were improved personal activity, increased mobility and recognition of family members. It is our opinion that camp-based intracapsular cataract extraction with aphakic correction is still an important alternative in rural India.

Activities of Daily Living↗
PubMed1995

Epilepsy in children with meningomyelocele.

The medical records of 89 children followed at a multidisciplinary Meningomyelocele Clinic at the Children's Clinics for Rehabilitative Services were reviewed. Almost all children in southern Arizona with meningomyelocele are followed at this clinic. Eight children (foreign nationals) were excluded because they were not eligible for neurosurgery/neurology services at the clinic. The remaining 81 children have been followed at the clinic from 0.25 to 21 years. Seventeen children (21%; age: 1.3-17 years, mean: 9.1 +/- 4.4 years; follow-up: 1.3-16 years) manifested seizures at some time during their course. All children with seizures had shunted hydrocephalus. Neonatal seizures occurred in 2 children currently not receiving medication. An additional 3 children had an acute symptomatic seizure associated with an intraventricular hemorrhage during ventriculoperitoneal shunt revision, 2 of whom later developed epilepsy. Fourteen children (17.3%) had epilepsy; 12 were taking antiepileptic drugs. Seizures were controlled on medication in 5 children. EEG abnormalities were present in 12 children (focal slowing 4, focal spikes 8, diffuse slowing 3, generalized or bilaterally synchronous spike-wave 4). Most of these children (12/14) had evidence of additional central nervous system (CNS) pathology (i.e., areas of encephalomalacia or past stroke 7, cerebral malformations 2, CNS calcifications 1, and frequent apneic spells/cardiac arrest 2). We conclude that epilepsy occurs in approximately 17% of children with meningomyelocele, and most have other CNS pathology to account for their seizures.

Adolescent↗
PubMed1995

Response of human epileptic temporal lobe cortical blood flow to hyperventilation.

Bilateral long-term surface cortical cerebral blood flow (CBF) and electrocorticographic (ECoG) monitoring were performed in eight patients with complex partial seizures. In each patient, the epileptic temporal lobe was localized using ictal ECoG. Mean seizure interval (frequency-1) off anticonvulsant medication, a clinical measure of epileptogenicity, was 1.0 +/- 0.3 h (range: 0.4 to 2.5 h). During 13 interictal hyperventilation periods, 3.6 +/- 0.6 min in duration, the mean decrease in epileptic and nonepileptic temporal cortical CBF was 13.7 +/- 2.3 versus 6.4 +/- 1.9 ml/(100 g min) (t = 2.230, d.f. = 16, P < 0.05), representing 20.9% and 10.8% reduction from baseline CBF during hyperventilation, respectively. Seizure interval decreased (i.e. frequency increased) with increasing magnitude of seizure focus CBF reduction during hyperventilation. Seizure interval was significantly correlated with epileptic temporal lobe CBF decrease during hyperventilation (R = 0.763, d.f. = 5, P < 0.05). The data suggest that, compared to nonepileptic brain, epileptic temporal lobe is particularly prone to hypoperfusion during hyperventilation. Epileptogenicity is a function of this seizure focus susceptibility to ischemia. The finding of abnormal seizure focus autoregulation during hyperventilation has implication for epileptic focus localization with cerebral blood flow analysis.

Adolescent↗
PubMed1995

Quantitative analysis of the electroencephalogram in the intracarotid amobarbital procedure: II. Coherence analysis.

Thirty-seven subjects underwent bilateral internal carotid artery injections of amobarbital before surgery for intractable epilepsy. The electroencephalograms (EEG) of these patients were continuously monitored during these 74 procedures and were later subjected to quantitative analysis. Analysis of interhemispheric coherence in the delta, theta, alpha, and beta 1 bands was performed. Prominent changes occurred in interhemispheric coherence, which showed a precipitous drop in the first 2 min after amobarbital injection, followed by a gradual return to near baseline levels. These results suggest that interhemispheric relationships are significantly disrupted by intracarotid amobarbital injection.

Adolescent↗
PubMed1995

Epileptic spasms in older children: persistence beyond infancy.

Although infantile spasms (IS) constitute a well-recognized epileptic syndrome, only recently did investigators propose that spasms be classified as a distinct seizure type, characterized by axial flexion/extension jerks in clusters. Five older children (aged 4.5-14.2 years) who underwent video-EEG monitoring in 1992 in our epilepsy program for intractable mixed seizure disorder (cryptogenic 1, symptomatic 4) demonstrated flexor and extensor spasms in clusters. Seizure onset was from birth to 1.33 years. All 5 had spasms during infancy that continued as the children aged. Ictal EEG during spasms showed a brief high-amplitude delta burst followed by diffuse background attenuation or diffuse background decrease with superimposed rhythmic beta or alpha activity. Multiple other seizure types were present. Interictal EEGs were markedly abnormal and demonstrated slowing, multifocal spikes, generalized slow spike-wave, and polyspike-wave. Two children with spasms were unsuccessfully treated with ACTH, and 3 underwent corpus callosotomy. We conclude that spasms occur in older children with intractable mixed seizure disorders and may persist beyond infancy.

Age Factors↗
PubMed1994

Quantitative analysis of the EEG in the intracarotid amobarbital procedure. I. Amplitude analysis.

Thirty-seven subjects underwent bilateral internal carotid artery injections of amobarbital prior to surgery for intractable epilepsy. The electroencephalogram (EEG) of these patients was continuously monitored during these 74 procedures and was later subjected to quantitative analysis. Topographic mapping of these data suggested that the areas of inactivation were largely restricted to the anterior 2/3 of the hemisphere injected, corresponding to the vascular distributions of the anterior and middle cerebral arteries. Graphical representation of the data demonstrated that delta and theta band activity peaked in the first 2 min post injection and decreased gradually thereafter, becoming stable at around 12 min post injection. Examination of the alpha, beta 1, and beta 2 bands suggested that activity increased and decreased more gradually than that for delta and theta, with perhaps a longer latency. Although EEG changes were most prominent in the anterior 2/3 of the inactivated hemisphere, similar (though smaller) changes were also observed in both ipsilateral and contralateral zones thought to be outside of the vascular distribution of the internal carotid artery.

Adolescent↗
PubMed1994

Amebic meningoencephalitis caused by Balamuthia mandrillaris.

Free-living amebae etiologically associated with central nervous system (CNS) infection in children have included Acanthamoeba, Naegleria, and recently, leptomyxid ameba. Two previously healthy children are reported with CNS infection caused by leptomyxid ameba, recently classified as Balamuthia mandrillaris. One child, a 27-month-old boy, had right hemiparesis and aphasia, and the other, a 13-year-old girl, had headache, right hemiparesis, diplopia, and left facial weakness. Cerebrospinal fluid studies of both children revealed a mononuclear pleocytosis and mildly elevated protein. The younger child developed seizures and progressive cerebrovascular occlusions; both developed hydrocephalus and coma progressing to death 16 days after onset of symptoms. The younger child at autopsy had necrotizing meningoencephalitis, left internal carotid arteritis, and amebic trophozoites and cysts in brain. Perivascular trophozoites were difficult to distinguish morphologically from macrophages in the older child, who had no cyst forms. Indirect immunofluorescence test revealed CNS infection with B. mandrillaris in both. This leptomyxid ameba, formerly considered an innocuous soil organism, should be considered in the differential diagnosis of progressive or atypical childhood stroke.

Adolescent↗
PubMed1994

Valproate-associated acute pancreatitis in a child with neuronal ceroid lipofuscinosis.

An 11-year-old girl with juvenile neuronal ceroid lipofuscinosis developed acute pancreatitis secondary to valproic acid treatment, which resolved after discontinuation of the medication and conservative treatment. To my knowledge, this is the first reported case of neuronal ceroid lipofuscinosis with valproate-associated pancreatitis. Children with neuronal ceroid lipofuscinosis may be susceptible to developing this complication.

Acute Disease↗
PubMed1994

Long-term surface cortical cerebral blood flow monitoring in temporal lobe epilepsy.

Long-term subdural surface cortical cerebral blood flow (CBF) and electrocorticographic monitoring was performed in 12 patients with complex partial seizures. A total of 40 seizures were analyzed. Baseline CBF values from nonepileptic and epileptic temporal lobe (mean +/- standard error) were 60.0 +/- 1.0 and 50.2 +/- 1.8 ml/100 g per minute, respectively (P < 0.05). In general, clinical seizure onset was preceded by a 20-minute preictal CBF increase from baseline in the epileptic temporal lobe. Peak early postictal CBF values of nonepileptic and epileptic temporal lobes were 57.7 +/- 13.3 and 89.0 +/- 21.7 ml/100 g per minute (P > 0.05) at 5.2 +/- 2.2 and 2.4 +/- 1.0 minutes (P > 0.05) after clinical seizure onset, respectively. Statistically significant differences between nonepileptic and epileptic temporal lobe CBF were detected at 50 minutes (74.0 +/- 14.2 and 37.5 +/- 9.2 ml/100 g per minute, respectively; P < 0.05) and 60 minutes (75.6 +/- 13.6 and 36.1 +/- 8.5 ml/100 g per minute, respectively; P < 0.05) postictal. The data suggest that the optimal times for CBF analysis to differentiate epileptic from nonepileptic temporal lobe are 1) during the interictal period and 2) late (50 to 60 minutes) postictal. The results of this study should improve the understanding of the dynamic cerebral perfusion patterns in the epileptic human brain.

Adolescent↗
PubMed1994

Comparative efficacy of diclofenac and flurbiprofen for maintenance of pupillary dilatation during cataract surgery.

A double-blind, prospective, randomized clinical study was undertaken to evaluate the relative efficacy of flurbiprofen 0.03% and diclofenac 0.1% eye drops, in combination with routinely used mydriatics, in maintaining pupillary dilatation during extracapsular cataract surgery with intraocular lens implantation. The effectiveness of administering systemic flurbiprofen along with the topical drugs in enhancing maintenance of pupillary dilatation also was assessed. Pupillary diameter, as measured at various surgical stages, was significantly greater in the patients receiving diclofenac or flurbiprofen eye drops as compared with those in a control group who did not (P < .001). While the maintenance of pupillary dilatation was consistently better with diclofenac than with flurbiprofen, the difference was not statistically significant. Furthermore, though maintenance of pupillary dilatation was better in cases in which systemic flurbiprofen was added to the preoperative drug regime, again, the difference was not significant.

Administration, Topical↗
PubMed1993

Ifosfamide-induced nonconvulsive status epilepticus.

We report the first case of nonconvulsive status epilepticus as a complication of chemotherapy with the nitrogen mustard derivative ifosfamide. Our patient developed encephalopathy, upper extremity myoclonus, and a periodic, triphasic electroencephalogic pattern that resolved acutely with intravenous diazepam treatment. Since significant morbidity and mortality is associated with unrecognized status epilepticus, electroencephalogic monitoring and a trial of diazepam is indicated in encephalopathic patients with rhythmic electroencephalogic patterns while receiving treatment with ifosfamide.

Brain↗
PubMed1993

Effects of enalapril, an ACE-inhibitor, on bronchial responsiveness in asthmatics.

To assess the effects of enalapril on bronchial responsiveness, we studied ten stable asthmatics and five healthy normal volunteers. Spirometry and methacholine bronchoprovocation dose (PC20) were measured before and after oral administration of 20 mg enalapril. Significant hypotensive effect was observed in all. More than two fold (2.73) increase in bronchial responsiveness was observed in the asthmatics (P < 0.01) without significant change in the expiratory flows. PC20 after enalapril fell by 56.8 +/- 23.0% of baseline value (P < 0.001). No significant change was observed in spirometric parameters and bronchial responsiveness in normal subjects. We conclude that enalapril significantly enhances BR and cannot be used safely in treatment of hypertension in asthmatics.

Adult↗
PubMed1993

Effect of calcium channel antagonists on cholinergic bronchial responsiveness in asthma.

Bronchial responsiveness to methacholine was studied in 23 stable asthmatics before and after nifedipine and diltiazem. There was no significant bronchodilatory effect of either calcium channel antagonists. The mean provocative dose of methacholine required to produce a 20% fall in FEV1 (PC20 = 0.157 +/- 0.74 mg) was not altered by nifedipine (PC20 = 0.159 +/- 0.61). However, diltiazem offered significant protection. The mean ratio of PC20 after diltiazem over baseline was 3.27 +/- 3.55. The results suggest that although both calcium channel antagonists have no influence on normal basal bronchomotor tone, diltiazem does significantly protect against cholinergic stimulation.

Asthma↗
PubMed1992

Sudden vision loss following retinal detachment surgery.

A 22-year-old man with Eales' disease with secondary rhegmatogenous retinal detachment with a break five disc diameters from the disc underwent radial scleral buckling using a silicone sponge episcleral explant with local cryopexy. Five hours after surgery the patient had no light perception. There was no intraoperative or postoperative rise of intraocular pressure or central retinal artery ischemia. Immediate removal of the explant brought a return of light perception and postoperative visual acuity improvement. The episcleral explant may have caused the direct optic nerve trauma that resulted in loss of vision.

Adult↗