Biomedical subjects
Publications and source records attributed to Vedantam Rajshekhar.
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Neurocysticercosis (NCC), infection of the central nervous system with larva of Taenia solium, presents in over 60% of patients in India as a solitary cysticercus granuloma (SCG). The low cyst number in these patients frequently results in an insignificant humoral response. Consequently, serological tests for patients with SCG must consider the detection of low antibody levels. Lentil lectin-specific T. solium glycoproteins of molecular weights 50, 38, 24, 18, 14 and 13 kDa are specific antigens for cysticercus antibodies in serological tests for NCC, however they do not detect antibodies in 40% of patients with SCG. To improve this rate of detection, the conformations of these protein antigens were altered to unmask additional epitopes available for antibody binding. Secondary structures of the proteins induced by reduction of disulfide bonds led to the loss of conformational epitopes necessary for cysticercus antibody recognition. Urea-induced tertiary conformations of the antigenic proteins led to the detection of antibodies in 46% of 60 patients with SCG who were serologically negative on immunoblots when the antigens were used in quaternary conformation. Conformation-sensitive immunoassays show potential for serodiagnosis of patients with SCG.
In a prospective study, memory and new learning ability functions were assessed pre-operatively (17 patients) and in the early post-operative period (22 patients) at 7-26 days following surgery in patients undergoing stereotactic transcortical excision of their colloid cysts. Pre-operative assessment detected impaired memory in 5 patients, 2 of whom had no memory-related complaints. Impaired new learning ability was detected pre-operatively in 7 patients. There was a statistically non-significant trend towards improvement in the dysfunction scores post-operatively in most patients. No correlation was detected between the cyst size, presence of raised intracranial pressure at presentation, hydrocephalus and the pre-operative dysfunction scores. Stereotactic transcortical resection of colloid cysts does not impair these functions in the majority of patients and might improve these functions in some. In the absence of clinical or radiological predictors of dysfunction of memory and new learning ability, pre-operative neuropsychological assessment has a role in detecting impaired memory and new learning ability in patients with anterior third ventricular colloid cysts who may not even complain of them.
BACKGROUND: Meningeal hemangiopericytomas are aggressive tumors that have a high rate of recurrence despite gross total resection and radiation therapy. Topoisomerase, a cell proliferation marker, is also a target of certain chemotherapeutic agents, and its nuclear levels are speculated to predict efficacy of targeted therapy. The aim of this study was to correlate the topoisomerase IIalpha proliferation index (TPI) with biologic behavior in intracranial hemangiopericytomas. METHODS: Clinical, radiological, and management data in 27 patients with intracranial hemangiopericytoma admitted between 1990 and 2003 were reviewed. Immunohistochemistry was performed on all the tumors using a monoclonal antibody to topoisomerase IIalpha, and the proliferation index was calculated. The effect of TPI on outcome was sought. RESULTS: The male/female ratio was 15:12. The mean age at presentation was 31.33 years. A radical excision of tumor was done in 18, subtotal excision in 2, partial excision in 4, and a biopsy in 3 patients. Tumor recurrence was noted in 15 (55.6%) of the 27 patients (mean follow-up duration, 51.5 months). The time to recurrence ranged from 7 months to 8 years (mean, 49 months). The 5-year recurrence-free survival was 33.8% in patients with a TPI of 5% or greater, and 72% in patients with a TPI of less than 5%. The relative risk of recurrence was 2.9 times greater in patients with a TPI 5% or greater as compared with those a TPI of less than 5%. CONCLUSION: Our study suggests that cases with a radical excision, radiation therapy, or a TPI index of less than 5% have a longer recurrence-free survival. A TPI of 5% or greater is a reliable predictor of recurrence.
BACKGROUND: Intraventricular cavernous angiomas are very rare. Only few cases of trigonal angiomas have been reported. CASE DESCRIPTION: We report three cases of trigonal cavernous angiomas who presented with raised intracranial pressure or seizures and who underwent total excision with a good recovery. We also review the literature and discuss surgical approaches. CONCLUSION: On magnetic resonance imaging, intraventricular cavernous angiomas lack the hemosiderin ring characteristically seen around parenchymal cavernous angiomas. This explains why trigonal cavernous angiomas can mimic malignant neoplasm on imaging, and they should be considered in the differential diagnosis of intraventricular masses. Total excision should be the goal of surgery.
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BACKGROUND: Cerebrospinal fluid diversion procedures are indicated in patients with hydrocephalus after tuberculous meningitis (TBM). We present 2 patients with hydrocephalus after TBM who were successfully treated with endoscopic third ventriculostomy (ETV). METHODS: Two patients had been diagnosed with hydrocephalus after TBM and had undergone ventriculoperitoneal shunt surgery for the same. They presented with multiple episodes of shunt dysfunction. Endoscopic third ventriculostomy was performed (twice for one patient), and the patients were evaluated clinically and radiologically after the procedure. RESULTS: On long-term clinical follow-up (3 and 2 years, respectively), both patients were asymptomatic after the ETV. The first patient was radiologically evaluated 7 months after the procedure and the second patient 2 years after the procedure. The first patient showed a decrease in ventricular size. The second patient did not show any significant change in the ventricular size. CONCLUSION: Endoscopic third ventriculostomy can be considered as a safe and long-lasting solution for hydrocephalus after chronic TBM.
BACKGROUND: Plasma cell tumors are rare neoplasms, which include extramedullary plasmacytoma, solitary plasmacytoma of the bone, and multiple myeloma. Although indistinguishable histopathologically, these entities need to be differentiated as treatment and prognosis vary. METHODS: This study was conducted by retrospective chart review and correspondence with patients diagnosed to have plasma cell tumors of the skull from 1992 to 2004. The clinico-diagnostic investigations, treatment, and subsequent follow-up of the patients were obtained. RESULTS: We report 5 cases of plasma cell tumors of the skull. The lesion involved the base of skull in 2 and the calvarium in 3 patients. In 2 cases, the histopathology was reported as plasmacytoma and further investigations revealed systemic involvement, indicative of multiple myeloma. In 1 patient, the biopsy was reported as multiple myeloma. The above 3 patients underwent radiation, followed by chemotherapy, and there was improvement in their neurologic status at subsequent follow-up. Another patient with a scalp swelling and symptoms of systemic involvement underwent investigations to detect multiple myeloma and, hence, was not subjected to an invasive procedure for histopathologic diagnosis. Chemotherapy was initiated but was discontinued because of social reasons. The last patient in our series died in the immediate postoperative period and although her histopathology was reported as plasmacytoma, she could not be evaluated for systemic involvement. CONCLUSION: The treatment options are different for the systemic form of disease and the localized disease; hence, it is imperative that a rigorous search for systemic involvement is conducted in a case of solitary or extramedullary plasmacytoma.
OBJECTIVE: We studied the long-term functional outcome in poor-grade patients (Nurick Grades 4 and 5) with cervical spondylotic myelopathy (CSM) or ossified posterior longitudinal ligament after central corpectomy (CC). We sought to determine whether there were any prognostic factors that could predict functional outcome in these patients. METHODS: Functional outcome data were collected for 72 patients (68 men and 4 women; mean age, 49.7 yr; range, 30-67 yr) with CSM (60 patients) or OPLL (12 patients) of Nurick Grades 4 (55 patients) and 5 (17 patients). Uninstrumented CC was performed at 1 level in 12 patients, at 1 level combined with a discoidectomy at another level in 4 patients, at 2 levels in 50 patients, and at 2 levels plus a discoidectomy in 5 patients. The age at presentation (< or =50 yr or >50 yr), grade before surgery (4 or 5), the number of levels operated (1 or >1), diagnosis (CSM or ossified posterior longitudinal ligament), and duration of myelopathic symptoms (< or =12 mo or >12 mo) were studied for their effect on the functional outcome noted at the last follow-up. Functional outcome was graded as poor (no change in Nurick grade), fair (improvement of one Nurick grade), good (improvement of two Nurick grades), and cure (follow-up Nurick grade of 0 or 1). RESULTS: The follow-up ranged from 9 to 104 months (mean, 36.3 mo). One patient died 3 weeks after CC after surgery for a perforated duodenal ulcer. There was transient operative morbidity in 12 patients (16.9%). The mean Nurick score improved from 4.24 to 2.47 (P < 0.001). Of the 54 patients (76%) who improved in their Nurick grade, the functional outcome was graded as fair in 13 patients (18.3%), good in 24 patients (33.8%), and cure in 17 patients (23.9%). The functional outcome was poor in 17 patients (23.9%). Functional improvement after CC was uniformly correlated with myelopathic symptoms of 12 months' duration or shorter. The other favorable prognostic indicators for improvement after CC were a diagnosis of CSM and preoperative Nurick Grade 5; however, patients with a preoperative Nurick grade of 4 were more likely to experience a cure. CONCLUSION: More than three-fourths of patients with poor-grade CSM improve in their functional status after CC, with nearly 24% of patients obtaining a cure. Because patients with a duration of myelopathic symptoms of 12 months or less had the best functional outcome, early decompressive surgery should be offered to patients with poor-grade CSM.
OBJECT: In this study, quantitative gait analysis is used to describe the changes in the kinematic and kinetic parameters of gait after central corpectomy in patients with cervical spondylotic myelopathy (CSM). METHODS: Six men with CSM that was categorized preoperatively as Nurick Grade 3 or 4 were assessed using quantitative gait analysis. The values of various kinematic and kinetic parameters, physiological cost index, and range of motion (ROM) in the lower-limb joints were computed preoperatively as well as at follow-up review 12 months or more postoperatively. Patients also received scores based on the Nurick and Japanese Orthopaedic Association (JOA) lower-limb functional scales pre- and postoperatively. The mean Nurick grade improved from 3.3 to 2 (p = 0.02) and the mean JOA lower-limb score improved from 4.2 to 6 (p = 0.02). The forward ground reaction force showed a statistically significant increase from 10.8+/-4.1% body weight to 12.1+/-3.6% body weight (p = 0.04). There was a significant improvement in the ROM at the knees, from 48.6+/-7.7 degrees to 54.2+/-5.2 degrees (p = 0.03). There was an increase in the mean walking speed, stride length, percentage of single-limb support time, vertical and backward ground reaction forces, and ROM at the hips in the postoperative gait analysis. These results indicate an improved stability of gait as well as greater flexibility in the knee after decompression of the spinal cord. These changes correlated with an improvement in the functional status of patients with CSM after central corpectomy. CONCLUSIONS: Gait analysis can be used as a quantitative tool in the pre- and postoperative evaluation of patients with CSM.
OBJECTIVE: To study the long-term seizure outcome and determine factors that predict recurrence of seizures following early withdrawal of antiepileptic drugs (AEDs) in patients with a solitary cerebral cysticercus granuloma (SCCG). METHODS: The authors prospectively studied 185 patients with SCCG and seizures in whom AEDs were withdrawn soon after (within 2 to 12 weeks) resolution of the SCCG was demonstrated on the CT scan. The follow-up of these patients ranged from 24 to 125 months (mean 65.8 months) or until seizure recurrence. Age, number of seizures, duration of AED therapy, occurrence of breakthrough seizures, administration of albendazole, and presence of a calcific residue of the SCCG on the CT scan were studied as prognostic factors to predict recurrence of seizures. RESULTS: One hundred fifty-seven patients (84.9%) were seizure-free, whereas 28 patients (15.1%) had recurrence of seizures after withdrawal of AEDs. The recurrences occurred at a mean duration of 18.8 months (range 0.5 to 78 months) after withdrawal of AEDs. Multivariate analysis showed that presence of calcific residue on the CT scan, occurrence of breakthrough seizures, and occurrence of more than two seizures were associated with a higher risk of recurrence of seizures. The other factors including administration of albendazole therapy did not affect seizure recurrence. CONCLUSIONS: Nearly 85% of patients with a solitary cerebral cysticercus granuloma have a good seizure outcome following resolution of the lesion and early withdrawal of AEDs. However, recurrence of seizures can be expected in about 15% of patients. Patients with more than two seizures, those with breakthrough seizures, and those whose follow-up CT scan shows a calcific residue of the granuloma have a higher risk of recurrence and therefore need to be appropriately cautioned after withdrawal of AEDs. AED therapy might also have to be continued for longer periods in patients with these risk factors.
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BACKGROUND: Total spondyloptosis of the cervical spine is a very rare injury. The authors describe an unusual case of post-traumatic total spondyloptosis of the cervical spine at C7-T1 level. CASE DESCRIPTION: A 40-year-old man presented with weakness of all four limbs, impaired sensations in all limbs and neck pain after a fall. A magnetic resonance image (MRI) of the cervical spine revealed a total spondyloptosis at C7-T1 level. He was managed successfully with ventral decompression and uninstrumented in situ fusion. The patient had a good neurologic outcome. CONCLUSION: Selected patients with spondyloptosis of the cervical spine can be successfully managed with uninstrumented ventral surgery.
BACKGROUND: Diagnostic criteria for posttraumatic brain tumors were formulated in the pre-CT (computerized tomography) era. We propose that radiologic criteria incorporating imaging data be added to the existing criteria. CASE DESCRIPTION: We report a case of a 56-year-old man who presented with history of raised intracranial pressure of 20 days' duration. Imaging showed a large left frontal intra-axial mass lesion. He had history of head injury 5 years prior with CT evidence of bilateral basifrontal contusions. There was no contrast enhancement at the site of the contusions in an intervening CT scan done 18 months after the trauma. He underwent radical excision of the mass, and the histopathology was reported as glioblastoma multiforme. We formulated additional radiologic criteria for tumors that may present following trauma. A review of the literature of posttraumatic gliomas is also presented. CONCLUSION: Fulfillment of the additional radiologic criteria proposed by us will help distinguish a tumor that developed following trauma from that which was present before the occurrence of the injury.
Necrobiotic xanthogranuloma (NXG) is a rare inflammatory histiocytic disease of the skin. Xanthogranuloma of the central nervous system is rare and few cases have been reported. To the authors' knowledge, there has been no previously reported case of NXG in which an intracranial lesion was found. This 52-year-old man, in whom NXG with all its cutaneous manifestations had been diagnosed, presented with three episodes of generalized tonic-clonic seizures. A contrast-enhanced computerized tomography scan of his brain revealed a bifrontal, dura-based mass lesion. The lesion was excised and reported to be an NXG that was similar, but not identical to the skin lesions. The patient was placed on a regimen of antiepileptic drug and chlorambucil after surgery.
OBJECT: The authors studied whether cervical spine motion segments adjacent to a fused segment exhibit accelerated degenerative changes on short-term follow-up magnetic resonance (MR) imaging. METHODS: Preoperative and short-term follow-up (mean duration 17.5 months, range 10-48 months) cervical MR images obtained in 44 patients who had undergone one- or two-level corpectomy for cervical spondylotic myelopathy were evaluated qualitatively and quantitatively. The motion segment adjacent to the fused segment and a segment remote from the fused segment were evaluated for indentation of the thecal sac, disc height, and sagittal functional diameter of the spinal canal on midsagittal T2-weighted MR images. Thecal sac indentations were classified as mild, moderate, and severe. New indentations of the thecal sac of varying severity (mild in 17 patients [38.6%], moderate in 10 [22.7%], and severe in six [13.6%]) had developed at the adjacent segments in 33 (75%) of 44 patients. The degenerative changes were seen at the superior level in 11 patients, inferior level in 10 patients, and at both levels in 12 patients and resulted from both anterior and posterior element degeneration in the majority (23 [69.6%]) of patients. The remote segments showed mild thecal sac indentations in seven patients and moderate indentations in two patients (nine [20.5%] of 44). Compared with the changes at the remote segment, the canal size was significantly decreased at the superior adjacent segment by 0.9 mm (p = 0.007). No patient sustained a new neurological deficit due to adjacent-segment changes. CONCLUSIONS: On short-term follow-up MR imaging, levels adjacent to the fused segment exhibited more pronounced degenerative changes (compared with remote levels) in 75% of patients who had undergone one- or two-level central corpectomy.
A 28-year-old man presented with history of raised intracranial pressure and one episode of generalized tonic clonic seizures. Computed Tomogram revealed multiple contrast enhancing intracranial lesions. Biopsy of one of the lesions was reported as metastatic alveolar soft part sarcoma. He was advised whole brain radiotherapy.