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Biomedical subjects

V Rajshekhar

Publications and source records attributed to V Rajshekhar.

At least 73 records · Page 4Linked to original sources
PubMed1998

Shunt surgery in poor grade patients with tuberculous meningitis and hydrocephalus: effects of response to external ventricular drainage and other variables on long term outcome.

Thirty two poor grade patients (grade 3, 20 patients and grade 4, 12 patients) with tuberculous meningitis and hydrocephalus were prospectively studied to evaluate the response to external ventricular drainage in predicting outcome after shunt surgery. All grade 3 patients underwent a shunt procedure irrespective of their response to external ventricular drainage, and an attempt was made to correlate the immediate response to external ventricular drainage to their long term outcome. Patients in grade 4 underwent shunt surgery only if there was clinical improvement by at least one grade after external ventricular drainage. Follow up (mean 23.1 months) was available for 30 patients (93%). Of the 20 patients in grade 3, seven underwent shunt surgery directly, 13 after an external ventricular drainage. In the group which underwent drainage, the immediate clinical response was improvement in six, no change in six, and death in one. Long term improvement or death occurred almost equally in all the subgroups. The immediate response to external ventricular drainage was not predictive of the long term outcome in grade 3 patients. All 12 patients in grade 4 underwent an external ventricular drainage and only one improved. The rest continued to deteriorate and succumbed to the disease. Grade at admission was the single most important predictor of good outcome (p=0.002) and severity of hydrocephalus had an adverse impact on outcome (p=0.04). The rest of the variables studied (age, duration of illness, duration of altered sensorium, CSF cell count, and CSF protein concentrations) had no effect on long term outcome. All patients in grade 3 should be given the benefit of shunt surgery without a trial of external ventricular drainage. However, patients in grade 4 should undergo an external ventricular drainage in view of the high mortality in this group.

Adolescent↗
PubMed1998

Solitary cysticercus granuloma of the brainstem. Report of four cases.

Isolated brainstem involvement in patients who have neurocysticercosis is rare. The authors describe the clinical and radiological features of four patients with a solitary cysticercus granuloma of the brainstem and discuss their case management. In three of the patients the onset of symptoms was fairly rapid, occurring over a few days. The granuloma appeared as an enhancing lesion measuring 20 mm or less, with a ring- or disklike appearance on computerized tomography and magnetic resonance imaging. A stereotactic biopsy provided the definitive diagnosis in one patient. In two patients the granuloma resolved spontaneously with complete regression of symptoms and signs and in one patient the granuloma resolved following albendazole therapy. In all patients, outcome was excellent or good (follow-up evaluation 6 months-3 years) with only one patient having persistent paresthesias on one side of his body. Because spontaneous resolution is the rule, a conservative approach to case management, including observation, is recommended. The importance of recognizing this entity and avoiding unnecessary surgical intervention or empirical antituberculous chemotherapy is emphasized.

Brain Diseases↗
PubMed1997

Tuberculomas presenting as isolated intrinsic brain stem masses.

We document the clinical presentation, management and outcome of histologically verified, solitary, intrinsic brain stem tuberculomas in six patients. The neurological symptoms and signs in these patients did not distinguish their lesions from other intrinsic masses of the brain stem. On contrast-enhanced computed tomography (CT), the tuberculomas appeared as ring enhancing lesions in three patients and nodular contrast enhancing lesions in the other three. Diagnosis was established on the basis of CT-guided stereotactic biopsy in all patients. All patients were treated with antituberculous drugs for 18 months. Steroid therapy of 2-8 weeks duration was also used in four patients. At a median follow-up period of 20 months (range 9-51 months), three patients were asymptomatic and the other three were functioning independently with mild disability. Although isolated, intrinsic brain stem tuberculoma is an uncommon entity, it should be suspected in patients presenting with features of an intrinsic brain stem mass and a contrast-enhancing lesion on CT. CT-guided stereotactic biopsy usually provides evidence of the inflammatory nature of the mass although an aetiological diagnosis is often elusive. Early diagnosis and appropriate therapy with antituberculous drugs and steroids usually results in an excellent or good outcome in most instances.

Adolescent↗
PubMed1997

Validation study of a central venous pressure-based protocol for the management of neurosurgical patients with hyponatremia and natriuresis.

OBJECTIVE: We had previously suggested a protocol for the management of neurosurgical patients with hyponatremia and natriuresis that was based on their volume status as determined by actual blood volume measurements. All patients in that study were found to be hypovolemic or normovolemic and responded, within 72 hours, to salt and fluid replacement. In the present study, the validity of that protocol was tested using central venous pressure as the sole measure of volume status of patients with hyponatremia and natriuresis. METHOD: Twenty-five consecutive patients (26 cases) who fulfilled the inclusion criteria typically used to diagnose the syndrome of inappropriate secretion of antidiuretic hormone were included in the study. Central venous pressure was used to classify patients as hypovolemic (< 5 cm of water), normovolemic (6-10 cm of water), or hypervolemic (> 11 cm of water). Hypovolemic patients were given fluids (50 ml/kg/d) and salt (12 g/d). Normovolemic patients were given normal fluid with 12 g of salt per day. In addition, patients with anemia (hematocrit, < 27%) were administered whole blood. The end point was a serum sodium of more than or equal to 130 mEq/L measured in two consecutive samples 12 hours apart or 72 hours after entry into the study. If the serum sodium was less than 130 mEq/L at the end of 72 hours, the clinical condition of the patient determined further management. RESULTS: Nineteen of 25 patients (26 cases) were hypovolemic, the rest were normovolemic. No patient was hypervolemic. Nineteen of 25 patients (26 cases) attained normal serum sodium values within 72 hours, and an additional 3 responded within the next 36 hours (108 h after entry into the study). One patient who was discharged on request had normalized her serum sodium a week later. Among the three nonresponders, who were severely hypovolemic, as revealed by blood volume measurement, and responded to increased fluid and salt administration. One was normovolemic and responded to increased salt administration. There were no complications related to the therapy. CONCLUSION: Hyponatremia with natriuresis in the neurosurgical setting responds to salt and fluid replacement guided by the patients' volume status as determined by the central venous pressure. This study also offers further indirect evidence to suggest that the syndrome of hyponatremia with natriuresis is most often caused by "cerebral salt wasting" rather than by the syndrome of inappropriate secretion of antidiuretic hormone.

Adolescent↗
PubMed1997

Validation of diagnostic criteria for solitary cerebral cysticercus granuloma in patients presenting with seizures.

OBJECTIVE: To evaluate a set of clinical and computed tomographic (CT) criteria (previously described by us) to predict the diagnosis of a solitary cerebral cysticercus granuloma (SCCG) at initial presentation, in patients presenting with seizures. MATERIAL AND METHODS: The diagnostic criteria were applied prospectively to patients presenting with seizures and solitary lesion on the CT scan. The clinical diagnostic criteria were as follows: seizures should be the presenting complaint; there should be no evidence of persistent raised intracranial pressure, progressive neurological deficit or an active systemic disease. The CT diagnostic criteria were: evidence of a solitary contrast enhancing lesion measuring 20 mm or less in its maximal dimension without a shift of the midline structures due to the surrounding oedema. A diagnosis of SCCG was made only when all the clinical and CT criteria were fulfilled. Over a period of 36 months, we managed 401 patients presenting with seizures and a solitary mass on the CT scan; 215 met the criteria for the diagnosis of an SCCG. RESULTS: Of the 215 patients initially diagnosed to have an SCCG, 197 were ultimately determined to have that diagnosis (true positive diagnosis) while 16 were excluded because of lack of follow-up CT assessment. Two of the 215 patients with the initial diagnosis of an SCCG subsequently had histological diagnosis of a secondary metastasis and a pyogenic abscess (false positive diagnosis). Our set of diagnostic criteria for SCCG had a sensitivity of 99.5%; specificity of 98.9%; a positive predictive value of 99%; and a negative predictive value of 99.5%. The likelihood ratios for the positive and negative tests were 92.99 and 0.005 respectively. CONCLUSIONS: Our diagnostic criteria help in not only accurately identifying an SCCG but also in differentiating it from a solitary tuberculoma and other brain masses. However, confirmation of the diagnosis of an SCCG is only obtained at follow-up evaluation and therefore careful clinical and CT re-evaluation is essential in all patients initially diagnosed to have an SCCG.

Albendazole↗
PubMed1996

Comparative study of CT and MRI in patients with seizures and a solitary cerebral cysticercus granuloma.

We hypothesized that when contrast-enhanced CT reveals a solitary cerebral cysticercus granuloma, MRI would not usually provide additional information that might assist in management. We retrospectively compared visualisation of solitary cysticercus granulomas on contrast-enhanced CT and MRI in 16 patients presenting with seizures; gadolinium (Gd) enhancement was used in 6 patients. The granuloma was delineated well on both CT and MRI in 15 patients; in one patient, in whom CT was performed with 10-mm slices, it was seen only on contrast-enhanced MRI, CT and unenhanced MRI revealing only the surrounding oedema. On CT the granuloma was seen best on thin (2-5 mm) contrast-enhanced sections (in 10 patients). On MRI, Gd-enhanced images showed the granuloma best, as a ring-enhancing lesion, in all 6 patients. In the other 10 patients, the granuloma was seen only on T2-weighted images in 8 and on both T1- and T2-weighted images in 2. On T2-weighted images a characteristic low-signal ring with a high-signal centre was seen in 12 patients. Sensitivity of the imaging techniques was: contrast-enhanced CT (5 and 10 mm slices) 93.8% (15/16); thin (2-5 mm) section contrast-enhanced CT 100% (6/6); unenhanced MRI 93.8% (15/16). MRI did not reveal additional granulomas or cysts in any patient. In patients strongly suspected to be harbouring this lesion, when 10-mm contrast-enhanced CT reveals only oedema, thin (2-5 mm) slice CT is a cost-effective alternative to MRI.

Adolescent↗
PubMed1995

Clinicoradiological and pathological correlations in patients with solitary cysticercus granuloma and epilepsy: focus on presence of the parasite and oedema formation.

A study of the clinical, radiological, and pathological correlations in 43 patients with solitary cysticercus granuloma and epilepsy focused on factors that might help in predicting the presence of the parasite in the granuloma and those that might influence the formation of oedema around the granuloma. The duration of symptoms (< six months and > or = six months) and CT morphology of the granuloma (ring and disc, type A; nodular lesion, type B) were studied as factors that could possibly predict the presence of the parasite in the granuloma. The influence of sex of the patient and the presence of a neutrophilic response in the granuloma on the intensity of oedema around the lesion as seen on CT was also studied. The pathological features were studied in the excised granulomas. The intact or degenerated form of the cysticercus was evident in 22 of 43 specimens. Neither the duration of seizures (P = 0.17) nor the type of lesion on CT (P = 0.16) was predictive of the presence of the parasite in the granuloma. The sex of the patient (P = 0.51) and the neutrophilic response in the specimen (P = 0.73) did not correlate with the degree of oedema on CT indicating that neither of these host factors was a major determinant of oedema production. The findings point to the varied and unpredictable natural history of solitary cysticercus granulomas and the complex nature of host-parasite interactions in individual patients. The inability to predict the presence of the parasite in the granuloma on the basis of the clinical or radiological features precludes a selection of patients with such lesions for cysticidal drug treatment.

Adolescent↗
PubMed1995

Computerized tomography-guided stereotactic surgery for brainstem masses: a risk-benefit analysis in 71 patients.

The benefits of the use of computerized tomography (CT)-guided stereotactic surgical techniques for the management of intrinsic brainstem masses diagnosed from clinical evaluation and imaging studies were evaluated vis-à-vis the risks involved in 71 consecutive patients. Seventy-two procedures were performed. The masses were diffuse, involving two or three contiguous brainstem segments, in 60 patients and focal in 11 patients. On the CT scans, 25 patients had hypodense nonenhancing masses, two had isodense nonenhancing masses, 19 had ring-enhancing masses, and 25 had heterogeneously enhancing masses. A positive biopsy was obtained in 68 of 69 patients (98.5%) undergoing a biopsy procedure. In nine patients (12.6%) with suspected malignant masses a benign pathology was diagnosed (four tuberculomas, two epidermoid cysts, one pyogenic abscess, one epidermal cyst, and one case of encephalitis). Additionally, fluid from cystic masses could be aspirated in eight cases, providing benefit in six (four patients had benign lesions and two had neoplastic lesions). Thereby, a total of 13 patients (18.3%) were deemed to have benefited from the surgery (two patients were included in both categories). Patients with focal masses and ring-enhancing masses had the highest proportion of benign lesions (60% and 36.8%, respectively) and therefore derived the most benefit from histological verification. There was no procedure-related mortality. One patient (1.4%) suffered permanent morbidity and four others (5.6%) had transient worsening attributable to the procedure. The authors conclude that CT-guided stereotactic surgery of the brainstem is safe and reliable. Histological verification of all enhancing (especially ring-enhancing) and focal brainstem masses should be undertaken to identify patients with benign nonneoplastic lesions. Selected patients with diffuse hypodense nonenhancing masses with atypical clinical or imaging features may also benefit from stereotactic biopsy. Even in these patients the lack of enhancement on a contrast-enhanced magnetic resonance image, rather than the diffuse location of the tumor alone, should form the basis for diagnosing a malignant glioma. The main value of stereotactic surgery lies in the identification of benign masses in a significant proportion of patients with intrinsic brainstem masses and in providing a rapid and safe method for evacuation of the contents of cystic masses.

Adolescent↗
PubMed1994

Management of neurosurgical patients with hyponatremia and natriuresis.

The main objective of our study was to evolve a practical management protocol for neurosurgical patients with hyponatremia and natriuresis, based on their blood volume status and hematocrit. Twenty-one patients with hyponatremia and natriuresis and 3 control patients were studied. Patients with hyponatremia were categorized on the basis of their hematocrit, central venous pressure, and total blood volume. Group A consisted of patients with hypovolemia and anemia (16 patients); Group B patients had hypovolemia but no anemia (5 patients); Group C included those with hypervolemia (0 patients). Patients in Groups A and B received isotonic saline (> 50 ml/kg/d) and oral salt (12 g/d). Additionally, those in Group A were transfused with 500 ml of whole blood. The end points in the study were 72 hours after entry or two consecutive serum sodium values of > 130 mEq/L, whichever was earlier. Hyponatremia was corrected in all the patients within 72 hours (1 patient, < 24 h; 13 patients, < 48 h; and 7 patients, < 72 h). We conclude that most neurosurgical patients with hyponatremia and natriuresis have hypovolemia, with or without anemia. Fluid and salt replacement and a blood transfusion rather than fluid restriction often results in the correction of the hyponatremia. Our findings offer indirect evidence to support the hypothesis that in most of these patients, hyponatremia is caused by cerebral salt wasting syndrome, rather than the syndrome of inappropriate secretion of antidiuretic hormone.

Adolescent↗
PubMed1994

Successful stereotactic management of a large cardiogenic brain stem abscess.

The brain stem is an unusual location for a pyogenic abscess. We report a case of a brain stem abscess in a 5-year-old boy with tetralogy of Fallot that was refractory to conservative medical therapy but was cured after a single computed tomographic-guided stereotactic aspiration and appropriate antibiotic therapy. The remarkable features in this case were the extremely large size of the abscess (3.2 cm in diameter), occupying the full vertical extent of the brain stem and containing 15 ml of pus. We believe this is the first report of a favorable outcome in a cardiogenic brain stem abscess. The value of computed tomographic-guided stereotactic surgery in the management of this lethal condition is documented with a review of the relevant literature.

Brain Abscess↗
PubMed1994

Predictive value of computed tomography-based diagnosis of intracranial tuberculomas.

The need to obtain histological diagnoses of intracranial tuberculomas, before initiating therapy, is not universally accepted, because some clinicians believe that an image-based diagnosis is fairly accurate in patients from endemic regions. To evaluate the sensitivity, specificity, and predictive value of computed tomography (CT)-based diagnosis of an intracranial tuberculoma, we prospectively compared the preoperative imaging diagnoses with histological diagnoses in 105 consecutive patients with intracranial masses. CT differential diagnoses (first or second) of tuberculomas were considered in 21 patients. Seven of them were histologically confirmed to have tuberculomas (true-positive results); 14 had other diseases (false-positive results). The 14 false-positive cases included 6 cases of astrocytomas, 5 of metastases, and 3 with miscellaneous diagnoses. All tuberculomas were correctly diagnosed on the CT scans (5 by both surgeons and 2 by one surgeon). During the study period, we encountered 11 patients who were referred by other clinicians with diagnoses of tuberculomas on the basis of their CT scans. We concurred with their CT diagnoses in 5 of them, but only 1 patient had a histologically verified tuberculoma. Astrocytomas (4 patients), metastases (3 patients), and solitary cysticercus granulomas (3 patients) were the causes of misdiagnosis in this group of patients. Although the sensitivity of CT in the diagnosis of intracranial tuberculomas is 100%, and its specificity is 85.7%, the positive predictive value is only 33% (confidence limits, 24-42%). The negative predictive value is 100%. The low positive predictive value for a diagnosis of intracranial tuberculoma on CT alone indicates the need for a confirming histological diagnosis.

Adolescent↗
PubMed1994

Mucoceles: a neurosurgical perspective.

The neurosurgical manifestations in three patients with sphenoid sinus mucoceles and two others with fronto-ethmoidal mucoceles are presented. In two patients, sphenoid sinus mucoceles produced visual loss while in the other severe headache was the only symptom. Both patients with fronto-ethmoidal mucoceles presented with proptosis. All patients had surgical treatment. While other symptoms were relieved following treatment, visual loss remained unchanged in both patients in whom it was present. We recommend a high level of suspicion for mucoceles as a cause of sudden or progressive visual loss. Prompt surgical therapy is needed to achieve good visual outcome.

Adolescent↗