Multiparametric imaging-based differentiation of lymphoma and glioblastoma: using T1-perfusion, diffusion, and susceptibility-weighted MRI.

AIM: To compare the diagnostic performance of T1 perfusion magnetic resonance imaging (MRI), diffusion-weighted imaging (DWI), and susceptibility-weighted imaging (SWI) for differentiating primary central nervous system lymphoma (PCNSL) and glioblastoma (GBM). MATERIALS AND METHODS: This retrospective study comprised a cohort of 70 patients with glioblastoma and 30 patients with PCNSL. T1 perfusion MRI-derived rCBV_corr (leakage corrected relative cerebral blood volume), apparent diffusion coefficient (ADC) derived from DWI, and intratumoural susceptibility signals intensity (ITSS) measured on SWI were evaluated in these 100 patients. The Mann-Whitney U-test was used for pairwise comparison between groups. The diagnostic performance for differentiating PCNSL from glioblastoma was evaluated by using univariate and multivariable logistic regression analyses and receiver operating characteristic (ROC) analysis. RESULTS: Minimum ADC, maximum rCBVs_corr, kep (back flux exchange rate), and ITSS scores were significantly lower in patients with PCNSL than in those with glioblastoma (p<0.05). On ROC analysis, ITSS showed the best discrimination ability for differentiation of GBM and PCNSL with an area under the ROC curve (AUC) of 0.80. rCBV_corr and ADC showed AUCs of 0.68 and 0.63, respectively. Multiparametric assessment using ADC, rCBV_corr, kep, and ITSS scores significantly increased the diagnostic ability for differentiating PCNSL from GBM as compared to mean ADC, mean rCBV_corr, and ITSS alone or a combination of these parameters. The multiparametric model could correctly discriminate 84% of tumours with a sensitivity and specificity of 90% and 70% with an AUC of 0.92. CONCLUSION: Multiparametric MRI evaluation using DWI, T1 perfusion MRI, and SWI enabled reliable differentiation of PCNSL and GBM in the majority patients, and these results support an integration of advanced MRI techniques for the diagnostic work-up of patients with these tumours.

Prospective glioma grading using single-dose dynamic contrast-enhanced perfusion MRI.

AIM: To evaluate the sensitivity and specificity of single-dose dynamic contrast-enhanced (DCE) perfusion magnetic resonance imaging (MRI) in prospective evaluation of glioma grading and to correlate the relative cerebral blood volume (rCBV) values with mitotic and ki-67 indexes obtained at histopathology. MATERIALS AND METHODS: A total of 53 histologically proven patients with glioma were included in this study. DCE-MRI perfusion with a single dose of contrast medium was included in brain tumour protocol and prospective grading of glioma into low and high grade was done based on a previously reported rCBV cut-off value of 3. Tumours with rCBV ≥ 3 were considered to be high grade and rCBV < 3 were considered to be low grade. The sensitivity and specificity of the cut-off value were estimated. Ki-67 and mitotic indexes were also obtained on histopathological analysis along with histological grading. RESULTS: Based on pre-defined rCBV cut-off values, prospective grading of low- and high-grade glioma was achieved with a sensitivity and specificity of 97.22% and 100%, respectively. Significant correlation was found between the mitotic/ki-67 indexes and rCBV values when data for high- and low-grade tumours was combined. CONCLUSION: DCE-MRI performed with a single dose of contrast medium is as effective as a protocol with a double-dose of contrast medium for glioma grading using 3 T MRI and could be added to the routine evaluation protocol of brain tumours.

Role of intraventricular sodium nitroprusside in vasospasm secondary to aneurysmal subarachnoid haemorrhage: a 5-year prospective study with review of the literature.

OBJECTIVE: Cerebral vasospasm remains an important cause of permanent neurological injury and death following aneurysmal subarachnoid haemorrhage, despite the best current medical therapy. Sodium nitroprusside was recently suggested as a treatment option for cerebral ischaemia in patients with severe medically refractive vasospasm after subarachnoid haemorrhage. METHODS: Twenty patients of aneurysmal SAH with severe vasospasm, corroborated on transcranial Doppler (TCD), were included in this prospective study. The neurological condition of all patients was classified as Hess and Hunt grade II or higher. The diagnosis of severe delayed cerebral vasospasm refractory to conventional treatment (HHH therapy and nimodipine) was established before treatment. Ten patients received intraventricular sodium nitroprusside (SNP), while the other 10 had either major systemic illness or did not consent, formed the control group of the study. SNP was instilled in escalating doses with a starting dose of 4 mg/mL and reversal of vasospasm was monitored on neurological examination along with TCD in a basic ICU setting without the need for neurophysiological or invasive monitoring. RESULTS: All patients in the study group showed an improvement in TCD velocities post-SNP instillation. Adverse effects were vomiting and hypotension in the SNP group which responded to medical management. The overall neurological outcome was good or excellent in 7/10 patients in the SNP group. Comparison between the two groups revealed improvement in TCD velocities and GCS in the SNP group thus affecting the long-term prognosis. CONCLUSION: Intraventricular sodium nitroprusside represents a promising method of treatment for established delayed cerebral vasospasm and cerebral ischaemia refractory to conventional treatment.

Sixth nerve schwannoma: a case report with literature review.

A 40-year-old woman presented with diplopia and left VI nerve palsy. After investigations, diagnosis of a meningioma in the parasellar-prepontine region was considered. Following angiography and embolization, near-total excision of the tumour attached to abducens nerve was performed. Histological examination was consistent with the diagnosis of schwannoma. This is the thirteenth case report of a schwannoma of cranial nerve VI and the first such case where embolization of feeding tumour vessels was performed.

Role of emergency surgery to reduce mortality from rebleed in patients with aneurysmal SAH.

Potentially salvageable patients with aneurysmal subarachnoid hemorrhage may rebleed and die after admission to a hospital, awaiting an angiogram or surgery. In an attempt to reduce the number of patients thus lost, we are operating on such patients on an emergency basis. This report is a retrospective analysis of patients operated early after aneurysmal SAH, but during routine working hours, versus patients operated on an emergency basis. During an 18 month period 109 patients underwent surgery for intracranial aneurysm. Fifty two (Group 1) patients were subjected to emergency clipping of the aneurysm, and 57 (Group 2) patients underwent early clipping but during routine working hours. There was no selection bias between the two groups. Another 10 patients in Hunt and Hess Grade II and III rebled and died, after admission, awaiting an angiogram or surgery. The overall mortality for the two groups (Grade I to IV) was 11.9%. Mortality in Groups 1 and 2 was 9.6% and 14.0% respectively. At 1 month, good outcome was recorded in 86.6% patients in grade I, 69.2% patients in grade II and 42.8% patients in grade III in group I compared to 68.7% patients in grade I, 80% patients in grade II and 31.5% patients in grade III in group 2. However, the difference was not statistically significant. There was also no significant difference between the incidence of intraoperative brain swelling and delayed ischaemic neurological deficit between the two groups. Grade IV patients had a poor outcome in both the groups. Angiographic vasospasm was associated with poor out come, in either group, in grade IV patients. Patients in Grades I to III should undergo emergency surgery, if the surgeon is experienced and willing to operate at odd hours and necessary support facilities of neuroradiology and neuroanaesthesiology are available. This would avoid deaths in patients awaiting angiograms or surgery.

Imaging appearances of meningeal melanocytoma.

Meningeal melanocytoma is an uncommon, benign melanocytic tumour of the meninges. Only 15 cases have been reported to date. We present the MR and CT appearance of a case of compressive myelopathy due to cervical meningeal melanocytoma. Careful analysis of the imaging features, as illustrated in the present case, allows a preoperative diagnosis. The differential diagnosis includes malignant melanoma and melanocytic meningioma.

Post-traumatic brain abscess: experience of 36 patients.

Thirty-six patients with post-traumatic brain abscess were managed over 18 years. They constituted 9.3% of all brain abscesses encountered during the same period. The head injury was associated with an external compound fracture in 20, internal compounding in three and was closed in 13 patients. The mean interval between the time of injury to presentation with an abscess was 113 days. This did not differ significantly in patients with closed and compound head injury, and amongst patients who had wound sepsis and with clean wounds after the injury. The occurrence of focal neurological deficit was more frequent in patients with a closed injury (p < 0.05). Twenty patients underwent primary excision of the abscess with recurrence of the abscess in one patient. Of the 14 patients in whom the abscess was initially aspirated, eight patients required a subsequent excision. Excision was required in 18 patients (94.7%) with external compound injury, five (50%) of those with closed injury and in all patients with internally compound injuries. Two patients had 'coned' and died before they could be operated upon. The operative mortality in the absence of signs of herniation preoperatively was 12.5% in patient with compound injury and none among patients with closed head injury.

Risk factors in postoperative neurosurgical infection. A prospective study.

Four hundred and seventy patients who had undergone neurosurgical operations were studied prospectively. After defining post-operative infection so that is included all the infective complications irrespective of location occurring after surgery, the overall infection rate was 17%. The infection rate in 413 cases without pre-existing infection was 15%. Wound infection was recorded in 5% and meningitis in 6%. Risk factors which lead to a significant increase in the incidence of postoperative infection were found to be altered sensorium, multiple operations, pre-existing infection, emergency surgery, duration of surgery more than 4 hours, urinary catheterisation, cerebrospinal fluid leak, and ventilatory support.

Complications related to pre-craniotomy shunts in posterior fossa tumours.

Among 344 patients with posterior fossa tumours treated from 1979 to 1986 a ventriculoperitoneal, or, less commonly, a ventriculatrial shunt was inserted in 164 cases pre-operatively. Haematoma following the insertion of a shunt was found to be an important cause of deterioration. While the occurrence of cerebrospinal fluid leak (p less than 0.3) and pseudomeningocele (p less than 0.01) was more frequent in the non-shunted cases, seizures (p less than 0.01) were found to occur more frequently in the shunted cases.