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Biomedical subjects

S V Thomas

Publications and source records attributed to S V Thomas.

34 records · Page 2Linked to original sources
PubMed1996

Reversible non enhancing lesions without focal neurological deficits in eclampsia.

Nine patients with eclampsia, were subjected to computerized tomographic scan (CT scan) of the head to ascertain the changes in the brain that accompany seizures and encephalopathy of eclampsia. Only those patients who had a seizure within the past 24 h were included in this study. None of the patients had any focal neurological deficit. Six of the nine patients had abnormal findings on CT scan consisting of multiple non enhancing hypodensities in the cerebral white matter. One patient also had subependymal haemorrhage over the lateral ventricle. These changes were found to have disappeared when the CT scan was repeated on the seventh day. There was no correlation between the mean arterial blood pressure or the number of seizures and the presence of hypodensities in the brain. These findings suggest that subclinical changes in the form of reversible hypodensities and rarely bleeding can occur in eclampsia even when patients have no focal neurological deficits. It appears that these lesions represent focal areas of cerebral oedema, secondary to failure of autoregulation of cerebral blood flow.

Adult↗
PubMed1995

Microsurgery without a microscope: laboratory evaluation of a three-dimensional on-screen microsurgery system.

In microvascular surgery, procedures may be both technically and physically demanding. Precise movements sustained over long hours in addition to typically compromised surgeon and assistant positioning lead quickly to physical and mental fatigue. Many of the positioning problems encountered are related to the fact that the eyes of the surgeon must be continually fixed to the microscope eyepieces. This study explores a possible solution: a microscope system that eliminates the need to view the operative field through the microscope eyepieces. A Three-dimensional On-screen Microsurgical System (TOMS) was used and contrasted with conventional operative microvascular surgery in the laboratory setting. The surgeon's comfort, his ability to instruct microsurgical technique, pertinent technological performance, and the procedure itself were evaluated using a standardized questionnaire. Based on data collected in this study, we conclude that divorcing the surgeon's eyes from the microscope eyepieces using the TOMS may make prolonged microvascular procedures less physically demanding and may increase the comfort level of both the surgeon and his assistant, although refinements to the technology are required.

Anastomosis, Surgical↗
PubMed1995

Interictal EEG changes in eclampsia.

The pathogenesis of seizures and encephalopathy in eclampsia remains obscure even today. There are only a few reports on EEG findings in eclampsia. This is a report of the interictal EEG changes in 8 patients with eclampsia who were evaluated prospectively. The major EEG changes observed were (1) slowing of the background activity (generalized slowing in 4 patients and focal slowing in 3 patients) and (2) intermittent spike and sharp wave transients (5 patients). These abnormalities had disappeared in all except 2 patients when the EEG was repeated on the seventh day. A comparison is drawn between eclampsia and hypertensive encephalopathy for the clinical, EEG and CT/MRI findings. The pathogenesis of seizures and encephalopathy could be similar in these two conditions. It is worth while considering these EEG changes while planning the treatment of eclampsia.

Adult↗
PubMed1995

Prolonged brainstem auditory evoked potential latencies in tropical pancreatic diabetics with normal hearing.

Twenty patients with Tropical Pancreatic Diabetes (TPD) were evaluated by Brainstem Auditory Evoked Potentials (BAEP) in order to detect any possible subclinical involvement of auditory pathways. The latencies of BAEP Wave III (p < 0.009) and V (p < 0.47) as well as the Interpeak Latencies I-III (p < 0.002), and I-V (p < 0.019) were significantly prolonged in patients with TPD when compared to age and sex matched healthy volunteers. There was correlation between the abnormalities of BAEP and duration of diabetes (p < 0.006), male sex of patients (p < 0.05), and the presence of retinopathy (p < 0.003) and nephropathy (p < 0.38). There was no significant correlation with the age of the patients, type of treatment, blood sugar levels and presence of peripheral neuropathy. These changes suggest a subclinical involvement of the auditory pathways in TDP patients.

Adult↗
PubMed1993

Balloon tamponade for liver injuries: case report.

A tamponade device for control of refractory liver bleeding is occasionally indicated. This report documents to our knowledge the first reported use of Foley catheter balloon tamponade for severe liver injury.

Adult↗
PubMed1993

Visual evoked potential changes in patients with tropical pancreatic diabetes.

Visual impairment is an important complication of diabetes. There are conflicting reports on Visual Evoked Potential (VEP) changes in diabetes. P100 latency of VEP was evaluated in twenty patients with Tropical Pancreatic Diabetes (TPD) and compared with that of age and sex matched controls. There was no statistically significant difference in the P100 latency between the two groups. There was no correlation between the P100 latency and the severity of diabetes or presence of defective vision or retinopathy. The defective vision in diabetes is likely to be due to ocular causes rather than due to a defect in the central visual pathways.

Adult↗
PubMed1989

Regional differences in capillary density of the normal human dermis.

Quantitative study of the capillary density of normal dermis of 113 biopsy specimens taken from 20 body sites from 6 cadavers was carried out. Histologic quantification of dermal capillaries using the alkaline phosphatase method to delineate vascular endothelium and automated image analysis demonstrates statistically significantly greater capillary density in the head-face/neck region both in the papillary and reticular dermis than in the lower parts of the body. The smallest numbers of the dermal capillary density were noted in the calf and shin areas. These data support the hypothesis that random-pattern skin flaps can be safely raised longer in the face and neck than in other parts of the body.

Aged↗
PubMed1983

The implicit assumptions of television research: an analysis of the 1982 NIMH report on television and behavior.

The authors analyze some of the assumptions underlying most current research on television. They emphasize the dependence on (1) an individual rather than an institutional level of analysis; (2) a model of research utilization that pays little explicit attention to where sources of leverage lie for changes in programming; (3) extremely simple models of the selection processes associated with different levels of television viewing; and (4) uncritical appraisals of the consequences of effects that many would call small or modest. These issues are illustrated by a general discussion of the NIMH report on Television and Behavior and specific discussion of "mainstreaming" and the effects of television violence. In 1972, POQ's editors invited Leo Bogart to prepare an extended review article of the Surgeon-General's Study of Television and Social Behavior (POQ 36:491-521). When the 10-year follow-up study was released by NIMH in 1982, the editors asked Thomas D. Cook, a distinguished psychologist noted for his research on television, to perform the same function.

Child↗
PubMedDate not supplied

Melanotic differentiation in dysembryoplastic neuroepithelial tumor.

Dysembryoplastic neuroepithelial tumor (DNT) is an uncommon intracranial tumor which is usually encountered in patients with medically intractable complex partial seizures of temporal lobe origin. Melanotic differentiation in a DNT has not been reported previously. Herewith we report a case of DNT with unique melanotic differentiation in a 23-year-old female who presented with medically intractable epilepsy. She underwent craniotomy and tumor decompression with a good outcome. We present the histopathological features of DNT with melanotic differentiation and discuss its prognostic significance.

Adult↗
PubMedDate not supplied

An expert system for the diagnosis of epilepsy: results of a clinical trial.

BACKGROUND: Artificial intelligence is an area where computer systems are used to solve real-life problems that require expert human intelligence. Expert systems serve as an effective alternative to supplement the dearth of human experts in a narrow domain of applications. We developed an expert system named SEIZ using DIAGNOS (an expert system shell for diagnostic applications) for the diagnosis and management of epilepsy. METHODS: A clinical trial was done to test the reliability of SEIZ. The clinical and demographic data from the medical records of 50 patients with epilepsy who attended an epilepsy clinic were provided to the expert system. The system-generated diagnosis was compared with the clinical diagnosis. RESULTS: The seizure types and epileptic syndromes for the 50 patients included generalized -tonic-clonic seizure (14), absence (4), complex partial seizure (18), simple partial seizure (4), juvenile myoclonic epilepsy (5) and other epileptic syndromes (3). There were two cases of hysterical conversion reaction. There was concordance in the diagnosis between the expert system and clinician in 47 cases (94%). The overall sensitivity was 94% and the specificity was 100% for absence, generalized tonic-clonic seizures, simple partial seizures and juvenile myoclonic epilepsy; 94% for complex partial seizures and 98% for hysterical conversion reaction. CONCLUSION: This expert system could generate reliable diagnoses for patients with epilepsy. Such a system may be useful for a doctor in a remote or peripheral area where an expert on epilepsy is not available.

Adult↗
PubMedDate not supplied

Prenatal screening for neural tube defects.

Neural tube defects are common birth defects with a prevalence of 4-15 per 10000 live-births. Prenatal diagnosis of neural tube defects has implications in obstetric management and many countries have successfully reduced their incidence by adopting nationwide preventive programmes. It is generally accepted that failure of the neural tube to close causes these defects. Periconceptional use of antiepileptic drugs such as valproate and carbamazepine and deficiency of folate is associated with a high incidence of these defects. Procedures for prenatal diagnosis include: (i) assessment of serum markers such as maternal serum alpha-foetoprotein and acetylcholinesterase activity; (ii) prenatal ultrasonography; and (iii) amniocentesis in selected cases. The levels of these two serum markers are increased in neural tube defects and a value of more than two multiples of the median is considered significant. The optimal time for serum screening is 10-18 weeks. In the case of serum markers it is important to apply normative data standardized for a laboratory and the duration of gestation. Antenatal ultrasonography is a simple, non-invasive and widely available test which has a similar sensitivity with lower false positivity compared to serum markers. Early diagnosis by ultrasound demands skill and experience in the procedure. Levels of amniotic fluid alpha-foetoprotein and acetylcholinesterase activity are elevated in neural tube defects. However, increased iatrogenic foetal loss is a disadvantage of this technique. Detailed counselling of the couple needs to be an integral part of the prenatal screening programme.

Female↗
PubMedDate not supplied

Management of epilepsy and pregnancy.

Epilepsy is recognized as the commonest serious neurological disorder in the world. Women with epilepsy (WWE) experience several gender-related physical and social problems. They constitute high obstetric risk because of reduced fertility, risk of seizures during pregnancy and complications of pregnancy. Hormonal and other factors can alter the pharmacokinetics of antiepileptic drugs (AED) during pregnancy and puerperium. Antenatal exposure to AEDs, particularly at higher dosage and in polytherapy, increases the risk of fetal malformation. Recent reports raise the possibility of selective developmental language deficits and neurocognitive deficits with antenatal exposure to AEDs. There are concerns regarding the effect of traces of AEDs that pass to the infant during breast-feeding. The pre conception management is the cornerstone for epilepsy care in WWE. A careful reappraisal of each case should ascertain the diagnosis, the need for continued AED therapy, selection of appropriate AEDs, optimization of the dosage and prescription of folic acid. During pregnancy, the fetal status needs to be monitored with estimation of serum a-feto-protein and ultrasound screening for malformations. The dosage of AEDs can be adjusted according to clinical requirement and blood levels of AEDs. Several institutions recommend oral vitamin K toward the end of pregnancy when enzyme-inducing AEDs are prescribed because the latter may potentially predispose the new born to hemorrhagic disease, but recent reports indicate that such a risk is practically negligible. WWE who are using enzyme-inducing AEDs (phenobarbitone, primidone, phenytoin, carbamazepine and oxcarbazepine) need to know that these AEDs may lead to failure of oral contraception.

Anticonvulsants↗
PubMedDate not supplied

Postal follow up of patients with epilepsy.

BACKGROUND: Epilepsy services in India are mostly located in urban areas and are often overcrowded. It is difficult, therefore, to organize long term management programmes. We report our experience at a tertiary referral centre on follow up of patients with epilepsy through regular postal review. METHODS: One hundred consecutive patients with epilepsy (63 men, 37 women, mean age 17 years) who had only seizures were followed up by post using a questionnaire, instead of reviewing them in a clinic. The safety, utility and efficiency of this system were evaluated. RESULTS: Sixty patients had generalized seizures, 30 had complex partial seizures and 10 had other types of seizures. The indication for shifting to postal review was good control of seizures in 87 cases and economic reasons in the remaining. Postal review constituted 60% of the total follow up period in 55 cases. Sixty-six patients could be maintained on postal review which was suspended or discontinued in 34 patients. Of these 34, 16 were returned to it after being seen in the clinic on a further occasion. Poor control of seizures, fresh medical or social problems, lack of confidence or a combination of these were the reasons for discontinuing the postal review. The economic benefit to a patient by way of savings in travel, incidental expenses and lost wages was estimated to be Rs 750 per annum. The work load in the epilepsy clinic was decreased by 40%. No serious medical problems or mortality were reported in the study population. CONCLUSION: Systematic postal review is a cost-effective alternative to clinic review in the long term follow up of a certain group of patients with epilepsy.

Adolescent↗
PubMedDate not supplied

Neuropsychological impairment and altered thyroid hormone levels in epilepsy.

BACKGROUND: Neuropsychological impairment is a common problem in epilepsy which interferes with the quality of life of patients. Similarly, thyroid hormone levels have been observed to be abnormal in patients with epilepsy on various treatments. This study aimed to ascertain any possible correlation between neuropsychological performance and thyroid hormone levels among epilepsy patients. METHODS: Thyroid hormone levels, indices of neuropsychological performance and social adaptation of 43 epilepsy patients were compared with those of age- and sex-matched healthy control subjects. RESULTS: Epilepsy patients exhibited significantly (p < 0.001) lower scores on attention, memory, constructional praxis, finger tapping time, and verbal intelligence quotient (i.q.) when compared with controls. Their T3, T4 and Free T3 levels were significantly lower; and TSH and Free T4 levels were significantly higher than that of controls. There was no statistically significant correlation between the indices of neuropsychological performance and thyroid hormone levels. CONCLUSION: We did not observe any correlation between neuropsychological impairment and thyroid hormone levels among patients with epilepsy.

Adult↗