Takeo Goto

Comparison of neuropsychological outcomes after selective amygdalohippocampectomy versus anterior temporal lobectomy

Transsylvian selective amygdalohippocampectomy (TSA) is an operative technique designed to spare unaffected brain tissue during surgical treatment for mesial temporal lobe epilepsy. In contrast to standard anterior temporal lobectomy (ATL), the advantages of TSA with respect to postoperative cognitive outcome are equivocal. We compared cognitive function before and after surgery in 49 patients with unilateral mesial temporal lobe seizures who underwent either ATL (n=17) or TSA (n=32). All patients received neuropsychological testing before and 1 year after surgery. The intelligence quotient (IQ) increased postoperatively in both surgical groups. Memory evaluation in the ATL group revealed a postoperative decline in nonverbal memory after right-sided resection and a postoperative decline in verbal memory after left-sided resection. In the TSA group, there was a slight postoperative decline only in verbal memory after left-sided resection, but other memory function was well preserved. In particular, there was significant postoperative improvement in verbal memory after right-sided resection. Overall, memory function was better preserved in the TSA group than in the ATL group.

The role of radical microsurgical resection in multimodal treatment for skull base meningioma.

OBJECT Because resection followed by timely stereotactic radiosurgery (SRS) is becoming a standard strategy for skull base meningiomas, the role of initial surgical tumor reduction in this combined treatment should be clarified. METHODS This study examined 161 patients with benign skull base meningiomas surgically treated at Osaka City University between January 1985 and December 2005. The mean follow-up period was 95.3 months. Patients were categorized into 3 groups based on the operative period and into 4 groups based on tumor location. Maximal resection was performed as first therapy throughout all periods. In the early period (1985-1994), in the absence of SRS, total excision of the tumor was intentionally performed for surgical cure of the disease. In the mid and late periods (1995-2000 and 2001-2005), small parts of the tumor invading critical neurovascular structures were left untouched to obtain good functional results. Residual tumors with high proliferation potential (Ki 67 index > 4%) or with progressive tendencies were treated with SRS. The extent of initial tumor resection, recurrence rate, Karnofsky Performance Scale score, and complication rate were investigated in each group. RESULTS The mean tumor equivalent diameter of residual tumors was 3.67 mm in the no-recurrence group and 11.7 mm in the recurrence group. The mean tumor resection rate (TRR) was 98.5% in the no-recurrence group and 90.1% in the recurrence group. A significant relationship was seen between postoperative tumor size, TRR, and recurrence rate (p < 0.001), but the recurrence rate showed no significant relationship with any other factors such as operative period (p = 0.48), tumor location (p = 0.76), or preoperative tumor size (p = 0.067). The mean TRR was maintained throughout all operative periods, but the complication rate was lowest and postoperative Karnofsky Performance Scale score was best in the late period (p < 0.001 each). Late-period results were as follows: mean TRR, 97.9%; mortality rate, 0%; and severe morbidity rate, 0%. Stereotactic radiosurgery procedures were added in 27 cases (16.8%) across all periods. Throughout all follow-up periods, 158 tumors were satisfactorily controlled by maximal possible excision alone or in combination with adequate SRS. CONCLUSIONS The combination of maximal possible resection and additional SRS improves functional outcomes in patients with skull base meningioma. A TRR greater than 97% in volume can be achieved with satisfactory functional preservation and will lead to excellent tumor control in combined treatment of skull base meningioma.

Bilateral subfrontal approach for tuberculum sellae meningiomas in long-term postoperative visual outcome

OBJECT Various surgical approaches, such as uni- and bifrontal, frontolateral, and pterional approaches, have been advocated for tuberculum sellae meningiomas. The authors retrospectively reviewed the effectiveness of a bilateral subfrontal approach for tuberculum sellae meningiomas with special attention to ophthalmological outcomes and complications. METHODS Between 1993 and 2009, 34 patients underwent surgery for removal of tuberculum sellae meningiomas at Osaka City University. Tumor size ranged from 14 to 45 mm. Thirty-two of 34 patients presented with visual disturbances before the surgery. The visual functions in all patients were assessed using a visual impairment score (VIS) before and after surgery. Postoperative visual examination was performed 2 weeks after surgery. Long-term follow-up examinations were conducted 1 year after surgery. RESULTS Radical resection (Simpson Grades I and II) was accomplished in 27 patients, and subtotal or partial resection (Simpson Grades III and IV) was achieved in 7. There was no deterioration in postoperative visual outcome. Twenty-nine (90.6%) of 32 patients showed improved VIS compared with preoperative VIS. The average VIS was 38.1 preoperatively, 23.5 in the short-term postoperative period, and 21.8 in the long-term postoperative period. In the short-term postoperative period, the visual function in 6 patients normalized, and visual problems persisted in the remaining 26. Six (23%) of 26 patients showed further improvement in VIS during the long-term follow-up period, and no patient exhibited a worsened VIS during this time. One patient complained of hyposmia after surgery, but there was no indication of related complications such as CSF leakage or frontal brain contusion. CONCLUSIONS The bilateral subfrontal approach was previously avoided because of the relatively high rate of complications in earlier surgical series of tuberculum sellae meningiomas. However, after developments in microsurgical techniques in recent years, the bilateral subfrontal approach can now provide satisfactory visual outcomes with minimal postoperative complications. Careful preservation of the blood supply to optic apparatus and early unroofing of the optic canal using a bilateral subfrontal approach led to further improvement in long-term postoperative visual outcome.

Schwannoma of the oculomotor nerve

A 63-year-old woman presented with an extremely rare oculomotor schwannoma not associated with neurofibromatosis, manifesting as a transient diplopia and ptosis. Magnetic resonance images showed a well-enhanced mass extending from the cavernous sinus to the intraorbital region. Surgical exposure confirmed the tumor originating from the oculomotor nerve in the cavernous sinus. The intraorbital cystic part of the tumor was partially resected to preserve the oculomotor function. This is the first case of oculomotor schwannoma in the cavernous sinus with intraorbital component.

Surgical outcomes of the minimum anterior and posterior combined transpetrosal approach for resection of retrochiasmatic craniopharyngiomas with complicated conditions

OBJECT Retrochiasmatic craniopharyngiomas are surgically challenging tumors. Retrochiasmatic craniopharyngiomas with complicated conditions such as large diameter, major calcification, or significant extension to the third ventricle or posterior fossa present surgical challenges; moreover, recurrent retrochiasmatic craniopharyngiomas are particularly formidable challenges. Although the transpetrosal approach to retrochiasmatic craniopharyngiomas published by Hakuba in 1985 can provide unique advantageous exposure of the retrochiasmatic area to allow safe neurovascular dissection and facilitate radical tumor removal, the procedure is viewed as complicated and time consuming and has a high risk of damaging hearing functions. The authors have modified Hakubas technique to minimize petrosectomy and reduce surgical complications and have applied this modified approach to retrochiasmatic craniopharyngiomas with complicated conditions. In this study, the authors describe their technique and surgical outcomes to elucidate the role of this modified transpetrosal approach for retrochiasmatic craniopharyngiomas with complicated conditions. This is the first study to report surgical outcomes of the transpetrosal approach for retrochiasmatic craniopharyngiomas. METHODS Between 1999 and 2011, the minimum anterior and posterior combined (MAPC) transpetrosal approach, which is a modification of Hakubas transpetrosal approach, was applied in 16 cases of retrochiasmatic craniopharyngiomas with complicated conditions. Eight cases were recurrent tumors, 4 had previously received radiotherapy, 11 had a large diameter, 10 had large calcification, 15 had superior extension of the tumor into the third ventricle, and 10 had a posterior extension of the tumor that compressed the midbrain and pons. In all 16 patients, more than 2 of these complicated conditions were present. The follow-up duration ranged from 0.8 to 12.5 years (mean 5.3 years). Surgical outcomes assessed were the extent of resection, surgical complications, visual function, endocrinological status, and neuropsychological function. Five-year and 10-year recurrence-free survival rates were also calculated. RESULTS Gross-total or near-total resection was achieved in 15 cases (93.8%). Facial nerve function was completely maintained in all 16 patients. Serviceable hearing was preserved in 15 cases (93.8%). Visual function improved in 13 out of 14 cases (92.9%) that had visual disturbance before surgery. None of the patients experienced deterioration of their visual function. Twelve cases had endocrinological deficit and received hormonal replacement before surgery. New endocrinological deficit occurred in 2 cases (12.5%). Neuropsychological function was maintained in 14 cases (87.5%) and improved in 1 case (6.3%). One case that had received previous conventional radiotherapy treatment showed a gradual decline in neuropsychological function. The 5-year and 10-year recurrence-free survival rates were both 86.5%. CONCLUSIONS The authors obtained good results by using the MAPC transpetrosal approach for the removal of retrochiasmatic craniopharyngiomas with complicated conditions. The MAPC transpetrosal approach should be considered as a therapeutic option for selected cases of retrochiasmatic craniopharyngiomas with complicated conditions.

Interictal Patterns of Cerebral Glucose Metabolism, Perfusion, and Magnetic Field in Mesial Temporal Lobe Epilepsy

Summary:  Purpose: To characterize the epileptogenic condition of patients with mesial temporal lobe epilepsy, the interictal patterns of glucose metabolism, perfusion, and magnetic field in the temporal lobe were evaluated by using [18F]fluorodeoxyglucose–positron emission tomography, [99mTc]‐ethylcysteinate dimer–single photon emission computed tomography, and magnetoencephalography (MEG).

Petroclival meningiomas resected via a combined transpetrosal approach: surgical outcomes in 60 cases and a new scoring system for clinical evaluation

OBJECT Petroclival meningiomas are among the most challenging intracranial tumors to treat surgically. Many skull base approaches have been described to improve resection and decrease patient morbidity. The authors undertook this study to evaluate the results of their treatment of petroclival meningiomas using objective measurements of tumor volume and a new impairment scoring system to assess neurological symptoms that severely affect the patients quality of life, such as impairment of swallowing and speaking, motor function, and consciousness and communication. METHODS Between January 1990 and December 2009, the authors used a combined transpetrosal approach to treat 60 patients with benign (WHO Grade I) petroclival meningiomas. In this retrospective study, all 60 cases were analyzed in detail with regard to tumor volume, extent of resection (EOR), long-term tumor control, neurological outcome, and the patient condition. In addition, patients were divided into 2 groups according to the period during which the surgery was performed: the early group, from 1990 to 1999, and the late group, from 2000 to 2009. A new scoring system, the petroclival meningioma impairment scale (PCMIS), was created for quantitative assessment of 8 categories of neurological functions, with scores assigned in each category according to the level of disability and its impact on the patient. The PCMIS was used preoperatively, at 3 months after surgery, and at the time of the last follow-up examination, and the results for the 2 groups were compared. RESULTS There were 24 cases in the early group (1990-1999), and the mean duration of follow-up was 149.3 months. The mean EOR was 96.1%, and good long-term tumor control was obtained in 22 patients (91.7%). One of patients died because of a postoperative complication in the perioperative period. The PCMIS improved in 3 patients (12.5%), remained stable in 1 (4.2%), and worsened in 20 (83.3%). There were 36 cases in the late group (2000-2009), and the mean duration of follow-up was 77.9 months. The mean EOR was 92.7%, and good long-term tumor control was obtained in 34 patients (94.4%). The PCMIS score improved in 23 patients (63.9%), remained stable in 5 (13.9%), and worsened in 8 (22.2%). CONCLUSIONS The combined transpetrosal approach has provided satisfactory functional improvements and excellent tumor control for patients with petroclival meningiomas. The PCMIS provides a specific tool for quantitative assessment of the patients state.

Microsurgical interruption of dural arteriovenous fistula at the foramen magnum

We report two rare cases of progressive congestive myelopathy caused by dural arteriovenous fistulae (DAVF) at the foramen magnum. The first, a 69-year-old male with a 2-year history of progressive myelopathy, had symptoms unrecognized due to a past history that included spinal caries and congenital dislocation of the hip. The second, a 60-year-old male, had a recurrence of the myelopathy three months after endovascular occlusion of the DAVF feeding artery. Both patients were successfully treated by direct microsurgical interruption of the arterialized medullary vein with functional and radiological improvement. The clinical manifestations of DAVF at the foramen magnum are nonspecific, mimicking those of cervical spondylotic myelopathy or cervical neoplasm. Accurate and early diagnosis followed by complete obliteration of the fistula is mandatory to avoid permanent neurological deficit.

Extra-axial subarachnoid ependymoma of the cerebral convexity.

Summary¶A 29-year-old man had two episodes of seizures in 9 months. Following the first seizure he developed hemiparesis, which gradually progressed. Investigations revealed a large cerebral convexity mass lesion simulating a meningioma. During operation, a reddish-brown and well-defined tumor located in the subarachnoid space was encountered. Histopathological examination revealed a typical ependymoma. Extra-axial cerebral convexity ependymomas are extremely rare. The case is reported and a brief review of six similar cases reported in the literature is undertaken.

Intracranial adenoid cystic carcinoma of suprasellar region.

Summary Adenoid cystic carcinoma (ACC) is a relatively common head and neck tumor which grows slowly but locally aggressive and prone to recurrence. ACC most commonly arises in the major and minor salivary glands, Some rare cases of intracranial ACC with an unknown primary site have been reported. The authors present the first case of primary intracranial ACC of the suprasellar region. A 34 year-old female presented with one months duration of visual disturbance and galactorrhea. Magnetic resonance image (MRI) showed intra- and suprasellar mass mimicking a craniopharyngioma. There was no evidence of invasion from an extracranial site. The operative findings showed the mass existed under the arachnoid membrane and seemed to originate from the pituitary stalk. Pathological diagnosis was ACC. After the first operation, local recurrence and CSF dissemination to the lower clivus occurred within two months. Recurrence repeatedly treated by Gamma knife radiosurgery 10 times and 4 times by surgery during a 3 year follow-up period. But total removal of the tumor at the first operation along with radiosurgery may control the lesion and prevent further recurrence.