Surgical Treatment of Tentorial Meningiomas ? Based on Our Classification Related to Venous Sinuses ?

We report our experience and long-term results in the surgical treatment of 27 tentorial meningiomas (TMs). These cases were operated on between 1980 to 2000.5 and represented 9.8% of all 275 surgically treated intracranial meningiomas in that period. Of the total 29 TMs (additional 2 non-surgically treated TMs), 25 were women and 4 were men ranging in age from 26 to 75 years (mean 55.2 years). According to the site of tumor attachment and the venous sinuses, these 29 TMs were divided into 6 subgroups: central (C; 3), anterolateral (AL; 3), posterolateral (PL; 6), free edge (FE; 6), anteromedial (AM; 3), and posteromedial (PM; 8). Various surgical approaches were selected on the tumor location and extension, however, these are divided into 2 approaches. One is anterior or posterior petrosal approach, selected in AL and FE cases and the other is combined occipital-suboccipital approach, selected in C, PL, AM, and PM cases. In 17 patients, total removal (Simpson Grade 1 : 8, II : 9) was achieved, subtotal removal (SG III) in 4, and partial removal (SG IV) in 6. Four patients had surgical complications. Gamma knife radiosurgery was performed in 4 residual and 3 recurrent meningiomas. In all these 7 meningiomas, tumor sizes have been well controlled. With a mean follow-up of 70 months (2 to 157 months), recurrences occurred in 5 patients (21.7%), which were subtotal and partial removal cases. Glasgow Outcome Scale scores were GR in 21 patients (77.8%), MD in 3 (11.1%), VS in 1 (3.7%), and D in 2 (7.4%)

Acute Cerebral Revascularization : Correlation among Preoperative CBF, Collateral Flow and Surgical Outcome

Twenty-two,patients,of,acute,cerebral,revascularization,were,analyzed,in,order,to,evaluate,various,predictors related to surgical effectiveness and outcome. These patients presented sudden neurological symptoms following occlusion of the middle cerebral artery (MCA). The left MCA was involved in 8 patients, and the right in 14 patients. Prior to surgical intervention, CT scan, serial angiography, and measurement of cerebral blood flow (CBF) were performed. STA-MCA anastomosis was completed in 21 patients, and left MCA embolectomy was performed on one patient. In the 14 patients of the effective group, the time elapsed from onset of stroke to revascularization was an average of 19.5 hours (6-72 hours). Of these patients,7 cases has a residual CBF of 24.8±1.2m1/100g/min (45% of normal CBF). Collateral flow, as judged from the preoperative angiograms, was good in 4 cases, and fair in 10 cases. In the 8 cases of the non-effective group, the time elapsed prior to the restoration of flow was an average of 8.2 hours (6-16 hours). Three cases had a residual CBF of 19.5 ±1.1m//100g/min. Collateral flow was fair in 5 cases, and poor in 3 cases. These results suggest that good preoperative collateral flow and residual CBF constitute the most accurate favorable predictors for the estimation of surgical effectiveness and outcome, and the time limits for acute cerebral revascularization is variable according to the degree of residual CBF supplied by collateral flow patterns

Surgical Treatment of Tentorial Meningiomas ー Based on Our Classification Related to Venous Sinuses ー

We report our experience and long-term results in the surgical treatment of 27 tentorial meningiomas （TMs）. These cases were operated on between 1980 to 2000.5 and represented 9.8% of all 275 surgically treated intracranial meningiomas in that period. Of the total 29 TMs （additional 2 non-surgically treated TMs）, 25 were women and 4 were men ranging in age from 26 to 75 years （mean 55.2 years）. According to the site of tumor attachment and the venous sinuses, these 29 TMs were divided into 6 subgroups: central （C; 3）, anterolateral （AL; 3）, posterolateral （PL; 6）, free edge （FE; 6）, anteromedial （AM; 3）, and posteromedial （PM; 8）. Various surgical approaches were selected on the tumor location and extension, however, these are divided into 2 approaches. One is anterior or posterior petrosal approach, selected in AL and FE cases and the other is combined occipital-suboccipital approach, selected in C, PL, AM, and PM cases. In 17 patients, total removal （Simpson Grade 1 : 8, II : 9） was achieved, subtotal removal （SG III） in 4, and partial removal （SG IV） in 6. Four patients had surgical complications. Gamma knife radiosurgery was performed in 4 residual and 3 recurrent meningiomas. In all these 7 meningiomas, tumor sizes have been well controlled. With a mean follow-up of 70 months （2 to 157 months）, recurrences occurred in 5 patients （21.7%）, which were subtotal and partial removal cases. Glasgow Outcome Scale scores were GR in 21 patients （77.8%）, MD in 3 （11.1%）, VS in 1 （3.7%）, and D in 2 （7.4%）

Acute Cerebral Revascularization : Correlation among Preoperative CBF, Collateral Flow and Surgical Outcome

Twenty-two,patients,of,acute,cerebral,revascularization,were,analyzed,in,order,to,evaluate,various,predictors related to surgical effectiveness and outcome. These patients presented sudden neurological symptoms following occlusion of the middle cerebral artery (MCA). The left MCA was involved in 8 patients, and the right in 14 patients. Prior to surgical intervention, CT scan, serial angiography, and measurement of cerebral blood flow (CBF) were performed. STA-MCA anastomosis was completed in 21 patients, and left MCA embolectomy was performed on one patient. In the 14 patients of the effective group, the time elapsed from onset of stroke to revascularization was an average of 19.5 hours (6-72 hours). Of these patients,7 cases has a residual CBF of 24.8±1.2m1/100g/min (45% of normal CBF). Collateral flow, as judged from the preoperative angiograms, was good in 4 cases, and fair in 10 cases. In the 8 cases of the non-effective group, the time elapsed prior to the restoration of flow was an average of 8.2 hours (6-16 hours). Three cases had a residual CBF of 19.5 ±1.1m//100g/min. Collateral flow was fair in 5 cases, and poor in 3 cases. These results suggest that good preoperative collateral flow and residual CBF constitute the most accurate favorable predictors for the estimation of surgical effectiveness and outcome, and the time limits for acute cerebral revascularization is variable according to the degree of residual CBF supplied by collateral flow patterns

MRI studies in two cases of hypertensive encephalopathy

Magnetic resonance imaging (MRI) findings were analyzed in two patients with hypertensive encephalopathy. MRI demonstrated focal cortical and subcortical lesions of hyperintense T 2 signal and hypointense Tl signal lesions with diffuse brain swelling. Focal lesions were hardly explained by involvements of major arterial supplies. There were no neurological focal signs suggesting dysfunctions in the abnormal areas of MRI. These MRI studies further support the hypothesis that hypertensive encephalopathy is induced by vasogenic edema during breakthrough of cerebral autoregulation. Prompt diagnosis and reduction of blood pressure are key points for improving the clinical condition. MRI better defines the cerebral involvements in detail and would help proper diagnosis and therapeutic decision