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Biomedical subjects

B A Chandramouli

Publications and source records attributed to B A Chandramouli.

At least 19 recordsLinked to original sources
PubMed2006

Loss of heterozygosity of the p53 gene and deregulated expression of its mRNA and protein in human brain tumors.

Tumor-specific alterations at the p53 gene locus were analyzed in 40 human brain tumor samples. Gliomas were more prevalent in young males and meningiomas in old females. Structural changes at the intron 1 region of the p53 gene were analyzed in these tumors by Southern blotting. Among the 40 tumors, 33 were informative and 21 of these (63.6%) informative cases showed loss of heterozygosity (LOH). This is the first report showing LOH at the intron 1 region of p53 gene in human brain tumors. The level of p53 mRNA, p53 protein and Ser 392 phosphorylated p53 protein were also analyzed in all tumor samples. Normal sized p53 mRNA and protein were present in all the tumor samples; however, their levels were 1.5- to 4-fold higher compared to the control suggesting deregulated p53 pathway in these tumors. No correlation was found between LOH status and the levels of p53 mRNA and protein. In all high-grade glioblastomas majority of the p53 protein existed as Ser 392 phosphorylated form as compared to low-grade gliomas. In addition, the percentage of Ser 392 phosphorylated form of p53 protein was lower in meningiomas and other brain tumor types irrespective of tumor grade. These results suggest involvement of Ser 392 phosphorylated form of p53 protein during the later stages of glioma development. These results also indicate that deregulation of p53 gene could occur at various steps in p53 pathway and suggest an overall deregulation of p53 gene in most brain tumor types.

Adult↗
PubMed2006

Hydrocephalus in Paget's disease.

Neurological manifestations in Paget's disease are rare. Hydrocephalus is infrequent, its etiology in Paget's disease being multi-factorial. Surgical and anesthetic procedures may be challenging, requiring special precautions. We describe one such case and discuss these peculiarities. An elderly lady, diagnosed to have Paget's disease presented with features of recent onset dementia, gait disturbances with urinary incontinence. Hydrocephalus secondary to posterior fossa crowding was present. A ventriculo-peritoneal shunt was inserted. Endotracheal intubation proved to be difficult. Modification of the surgical technique was required to ensure a safe procedure. She improved immediately following CSF diversion. Timely CSF diversion yields good results. Certain precautions during anesthesia and surgery can ensure a safe and uneventful peri-operative period.

Aged↗
PubMed2006

Third ventricular colloid cysts in children.

INTRODUCTION: Colloid cysts of the 3rd ventricle are relatively rare intracranial tumours, more so in children. They are benign tumours with excellent prognosis if diagnosed and treated early. METHODS: A retrospective analysis of 18 cases of colloid cysts in children below 18 years, operated in our institution between September 1998 and November 2003 (5 years) was made. Clinical presentation, radiological findings, surgical approaches and outcome were analysed. RESULTS: Age ranged from 7 to 18 years. The male-to-female ratio was 12:6. Headache and vomiting were the most common symptoms. Papilloedema was the most common clinical sign. Pre-operative CT showed a hyperdense non-enhancing lesion in the majority. Twelve patients underwent a transcallosal, 2 a transcortical and 4 an endoscopic approach. Ventriculoperitoneal shunts were done in 5 patients. Postoperatively 2 patients developed epidural haemorrhage which required evacuation. One patient was re-explored for symptomatic residue. A mean follow-up of 10.2 months was available in 9 patients; the majority were asymptomatic. CONCLUSION: Colloid cysts though rare are increasingly detected in children. Their early recognition and treatment give excellent results.

Adolescent↗
PubMed2005

Management of craniovertebral junction tuberculosis.

BACKGROUND: Tuberculosis of the craniovertebral junction (CVJ) is extremely rare. However, recent evidence suggests that the incidence of this condition may be increasing. The diagnosis is often difficult despite advances in imaging using magnetic resonance imaging. The transoral approach to the anterior CVJ provides excellent access to this region, has low mortality and morbidity, and enables biopsy of lesions and decompression of the neuraxis. Management of associated atlantoaxial instability, with regard to timing and method of stabilization, is controversial. METHODS: We report 24 cases of CVJ tuberculosis. Prominent manifestations of the disease included neck pain and stiffness, swelling of the retropharyngeal soft tissues, quadriparesis, osteolytic erosions, and atlantoaxial subluxation. Seven patients had acute presentation. All patients received antituberculous drug treatment for 18 months. Four patients were managed conservatively, 5 underwent only transoral biopsy, 9 patients underwent transoral decompression and posterior fusion, and 6 patients underwent only posterior fusion. RESULTS: Histopathologic analysis of biopsy material revealed abscess only in 5 cases, granulation tissue only in 6, abscess with granulation tissue in 4, granulation tissue with chronic osteomyelitis in 5, and chronic inflammation in 2. All patients improved, with mean improvement in Nurick grading of 1.71. Even patients with spinal cord signal intensity changes on magnetic resonance images showed improvement. CONCLUSIONS: Although CVJ tuberculosis is a rare disease, the outcome of treatment is good. Antituberculous drug therapy remains the mainstay of treatment after confirming the diagnosis. The surgical management options include transoral decompression with or without posterior fusion, depending upon the presence and persistence of atlantoaxial instability.

Adolescent↗
PubMed2003

Evaluation of nimodipine in the treatment of severe diffuse head injury: a double-blind placebo-controlled trial.

AIMS: The aim of this study was to establish whether nimodipine given orally soon after severe diffuse head injury for a period of three weeks improved outcome. MATERIAL AND METHODS: The present report analyzes the results of a prospective randomized double-blind placebo-controlled trial of nimodipine in 97 severe head injury patients (GCS Score < or =8) treated at the Department of Neurosurgery, NIMHANS, between January 1995 and June 1996. The patients were randomly assigned to two groups which were matched for age, sex, mode of injury, time interval from injury to admission, neurological status and CT scan findings. One group was given nimodipine 30 mg Q6H and the other group was given a placebo. The outcome of these patients at 6 months was evaluated using the Glasgow Outcome Score by and a psychologist. RESULTS: Results showed no significant difference in the functional and psychological outcome between the two groups, even in patients with subarachnoid hemorrhage. No adverse drug events were recorded. CONCLUSION: Oral nimodipine given for three weeks does not improve outcome in patients with severe diffuse head injury.

Adolescent↗
PubMed2002

Intraoperative bradycardia and postoperative hyperkalemia in patients undergoing endoscopic third ventriculostomy.

During our initial experience with endoscopic third ventriculostomies, we observed intraoperative bradycardia and postoperative hyperkalemia. The present study was carried out to verify the consistency of these initial observations. Intraoperative heart rate (HR) changes and postoperative serum K + changes were studied prospectively in 20 patients of endoscopic third ventriculostomy. Another 6 patients who underwent endoscopic procedures other than ventriculostomy acted as controls. The anaesthetic technique and intraoperative and postoperative fluid regimen were similar in all patients. Serum K + concentrations were measured intraoperatively and once a day for the next 5 days. The third ventriculostomy group exhibited a significant slowing of the heart rate during the fenestration of the floor of the third ventricle (112 +/- 26 to 101 +/- 28 bpm, p < 0.001) and also at the time of the reversal of the neuromuscular block at the end of surgery (104 +/- 29 to 96 +/- 33 bpm, p < 0.01). The control group did not exhibit similar changes in the heart rate. The postoperative increase in serum K + values in the ventriculostomy group (0.82 +/- 0.55 mmol/L) was higher than that in the control group (0.10 +/- 0.44 mmol/L) (p < 0.01). Endoscopic third ventriculostomy is associated with a significant bradycardia at the time of fenestration and at the time of reversal of the neuromuscular block. The procedure is also associated with a postoperative increase in serum K + values. We propose a mechanism involving distortion of the posterior hypothalamus, which accounts for the bradycardia and postoperative hyperkalemia.

Adolescent↗
PubMed2002

Spinal intramedullary tuberculoma and abscess: a rare cause of paraparesis.

Five cases of spinal intramedullary tuberculomas (IMT) and one case of spinal intramedullary tuberculous abscess (ITA) are presented. Gd enhanced MRI revealed ring enhancing lesion with central hypodensity, suggesting granulomatous pathology. Surgical excision of the intramedullary lesions was carried out in four cases, while two patients received presumptive anti-tuberculous chemotherapy only. Repeat MRI after completion of anti-tuberculous therapy showed total resolution of the lesion. In other cases following surgical excision, the patients improved significantly. The management of these rare lesions is discussed and the literature reviewed.

Adult↗
PubMed2000

Safety of acute normovolemic haemodilution with hydroxyethyl starch during intracranial surgery.

The effect of acute normovolemic haemodilution on haemodynamics, serum osmolality and coagulation parameters was studied in 20 patients undergoing intracranial surgical procedures. After induction of anaesthesia, 740+/-153 ml of blood was collected and the same was replaced with an equal volume of 6% hexaethyl starch. Heart rate (HR), blood pressure (BP), central venous pressure (CVP) and end tidal carbon dioxide tension (Et CO2) were monitored for 45 min. Haemoglobin concentration (Hb), haematocrit (Hct), serum osmolality (Osm), bleeding time (BT), prothrombin time (PT) and platelet count were determined before and 45 min after haemodilution. Hb and Hct were significantly lower following haemodilution (13.1+/-1.8 and 10.3+/-1.7 g/dL for Hb and 38.0+/-4.6%. and 30.1+/-4.5% for Hct). There was no significant change in the HR, BP and Et CO2 throughout the study period. CVP increased marginally from 35 to 45 min but was within normal limits. There was no significant change in serum osmolality, bleeding time and prothrombin time following haemodilution. Platelet count decreased following haemodilution but the values were within normal limits. The brain relaxation, as assessed by a semiquantitative scale, was satisfactory in all cases. None of the patients developed intraoperative brain swelling. In conclusion, acute normovolemic haemodilution with hexaethyl starch is tolerated well haemodynamically. It does not cause changes in serum osmolality which can increase brain oedema. It has no adverse effect on intraoperative haemostasis. It is a safe technique to decrease homologous blood transfusion during intracranial surgery.

Adult↗
PubMed2000

Intramedullary spinal epidermoid cyst.

Intramedullary epidermoid cysts of the spinal cord are rare tumours, especially those not associated with spinal dysraphism. Around 50 cases have been reported in the literature. Of these, only seven cases have had magnetic resonance imaging studies. We report two cases of spinal intramedullary epidermoid cysts with MR imaging. Both were not associated with spina bifida. In one patient the tumour was located at D4 vertebral level, while in other within the conus medullaris. The clinical features, MR imaging characteristics and surgical treatment of such rare intramedullary benign tumours are discussed, and the relevant literature reviewed.

Adolescent↗
PubMed1999

Cavernous-venous malformation of brain stem--report of a case and review of literature.

BACKGROUND: Because of improved imaging techniques, the association of cavernous and venous malformations is now being seen more often in neurosurgical practice. However, only a few cases have been subjected to surgery. Surgical excision of the cavernous malformation, sparing the venous component, has been the method of choice advocated by most authors. This, however, is not possible when the components are intimately associated with each other. It thus becomes important to predict the surgical outcome in such lesions, especially when they are located in an eloquent area. A surgically excised case of cavernous-venous malformation in the dorsal pontomedullary region is presented here; the histology confirmed the intimate association of both components. The relevant literature is also discussed. CASE DESCRIPTION: This 20-year-old male presented with episodic vomiting, giddiness, and persistent cerebellar signs over a six-year period. Neuroimaging studies-computed tomography scan/magnetic resonance imaging (CT/MRI) were suggestive of a cavernous malformation. MRI also showed a draining vein close to the lesion. Following total excision, histopathology confirmed the intimate association of both cavernous and venous malformations. The patient made an uneventful recovery. MRI at follow up confirmed total excision. CONCLUSIONS: The presence of venous channels draining into a lesion that otherwise appears to be a cavernous malformation may indicate an intimately associated venous component. Selective surgical excision of the cavernous component may be difficult in such cases. Surgical outcome, though favorable in this case, will be difficult to comment upon unless more such cases are reported. This may be of greater significance in lesions located in eloquent areas.

Adult↗
PubMed1999

Trigeminal evoked potentials in patients with symptomatic trigeminal neuralgia due to intracranial mass lesions.

Trigeminal evoked potentials (TEP) were recorded by electrical stimulation of the lips in 7 patients with symptomatic trigeminal neuralgia due to CT proved mass lesions involving the trigeminal nerve. All the patients showed TEP abnormalities on the affected side. Chronic compression and irritation of the trigeminal nerve may be responsible for these changes. The results obtained were compared with other similar studies and TEP abnormalities observed in idiopathic trigeminal neuralgia. As all the patients had unequivocal compression of the trigeminal nerve and all of them had TEP changes, it can be concluded that TEP abnormality is an accurate predictor of trigeminal nerve compression. TEPs may be a valuable aid in demonstrating a compressive element in patients with trigeminal neuralgia.

Brain Neoplasms↗
PubMed1999

Evaluation of posttraumatic vasospasm, hyperaemia, and autoregulation by transcranial colour-coded duplex sonography.

Serial transcranial colour-coded duplex sonography (TCCS) was performed on 24 adult patients with severe head injury (GCS 8 or less). Flow velocities were obtained from the middle cerebral artery (MCA) and extracranial internal carotid artery (EICA). An autoregulation study was done using the transient hyperaemic response test, evidence of vasospasm (V-MCA greater than 100 cm/s and Lindegaard ratio more than 3) was found in nine patients (37%). Two of these developed non-contusion-related infarction and two others contusion-related infarction. This was significant (p < 0.05). Vasospasm started around day 2, reaching maximum around day 4 and persisting until the second week. Vasospasm was significantly associated with a poor outcome (p < 0.05). There was no correlation between the extent of SAH as seen on CT and vasospasm. Evidence of hyperaemia were observed in two patients (8%) and impaired autoregulation in seven patients (29%). Impaired autoregulation was significantly associated with development of hyperaemia (p < 0.05). TCCS studies permit a non-invasive evaluation of cerebral haemodynamics that will help in the management of head injured patients.

Adolescent↗
PubMed1997

Experience with cerebellopontine angle epidermoids.

OBJECTIVE: Cerebellopontine angle (CPA) epidermoids, although of benign nature, are of considerable neurosurgical interest because of their close proximity and adherence to the cranial nerves and the brain stem. We describe our experience and attempt to correlate the final outcomes with the extent of surgical removal. METHODS: Twenty-five consecutive patients with CPA epidermoids that were surgically treated were reviewed, and the final outcomes were assessed. RESULTS: Thirteen patients had trigeminal neuralgia. In 7 of the 13 patients, trigeminal neuralgia was the only presenting feature. The epidermoid was confined to the CPA in each of 6 patients, and in each of 18, it had varying degrees of supratentorial extension. One patient had a predominant supratentorial epidermoid with extension to the CPA. The lesions were totally excised in 12 patients. Near-total removal was accomplished in eight patients, and in the remaining five, partial removal was accomplished. Transient worsening of the cranial nerve functions occurred in 11 patients, probably as a result of aggressive dissection of the capsule from the cranial nerves. In 9 of the 11 patients, the cranial nerve functions improved by the time of discharge. All of the patients who had trigeminal neuralgia were relieved of their symptoms. Eighteen patients were followed up for a mean period of 42 months, and none had symptoms of recurrence. CONCLUSION: Aggressive surgical removal results in transient but significant cranial nerve dysfunction in the postoperative period. A conservative approach is indicated for patients in whom the capsule is adherent to the brain stem and the cranial nerves.

Adolescent↗
PubMed1997

Anomaly of arch of atlas--a rare cause of symptomatic canal stenosis in children.

Symptomatic canal stenosis at the level of atlas (C1) without atlantoaxial dislocation is thought to be very rare in children. Though common, anomalies of the arch of atlas are generally incidental findings in X-rays. High cord compression due to a narrow canal from a bifid posterior arch, or an absent posterior arch, is a very rare condition. We report 5 children with high cord compression from stenosis of C1 arch.

Cervical Atlas↗
PubMed1996

Improving cancer radiotherapy with 2-deoxy-D-glucose: phase I/II clinical trials on human cerebral gliomas.

PURPOSE: Evaluation of tolerance, toxicity, and feasibility of combining large fraction (5 Gy) radiotherapy with 2-deoxy-D-glucose (2DG), an inhibitor of glucose transport and glycolysis, which has been shown to differentially inhibit repair of radiation damage in cancer cells. METHODS AND MATERIALS: Twenty patients with supratentorial glioma (Grade 3/4), following surgery were treated with four weekly fractions of oral 2DG (200 mg/kg body weight) followed by whole brain irradiation (5 Gy). Two weeks later, supplement focal radiation to the tumor (14 Gy/7 fractions) was given. Routine clinical evaluation, x-ray computerized tomography (CT), and magnetic resonance (MR) imaging were carried out to study the acute and late radiation effects. RESULTS: All the 20 patients completed the treatment without any interruption. The vital parameters were within normal limits during the treatment. None reported headache during the treatment. Mild to moderate nausea and vomiting were observed during the days of combined therapy (2DG + RT) in 10 patients. No significant deterioration of the neurological status was observed during the treatment period. Seven patients were alive at 63, 43, 36, 28, 27, 19, and 18 months of follow-up. In these patients, the clinical and MR imaging studies did not reveal any late radiation effects. CONCLUSIONS: Feasibility of administering the treatment (2DG + 5 Gy) is demonstrated by the excellent tolerance observed in all 20 patients. Further, the clinical and MR studies also show the absence of any brain parenchymal damage.

Adult↗