Optimal access route for pontine cavernous malformation resection with preservation of abducens and facial nerve function.

OBJECTIVE: The aim of this study was to analyze the differences between posterolateral and posteromedial approaches to pontine cavernous malformations (PCMs) in order to verify the hypothesis that a posterolateral approach is more favorable with regard to preservation of abducens and facial nerve function. METHODS: The authors conducted a retrospective analysis of 135 consecutive patients who underwent microsurgical resection of a PCM. The vascular lesions were first classified in a blinded fashion into 4 categories according to the possible or only reasonable surgical access route. In a second step, the lesions were assessed according to which approach was performed and different patient groups and subgroups were determined. In a third step, the modified Rankin Scale score and the rates of permanent postoperative abducens and facial nerve palsies were assessed. RESULTS: The largest group in this series comprised 77 patients. Their pontine lesion was eligible for resection from either a posterolateral or posteromedial approach, in contrast to the remaining 3 patient groups in which the lesion location already had dictated a specific surgical approach. Fifty-four of these 77 individuals underwent surgery via a posterolateral approach and 23 via a posteromedial approach. When comparing these 2 patient subgroups, there was a statistically significant difference between postoperative rates of permanent abducens (3.7% vs 21.7%) and facial (1.9% vs 21.7%) nerve palsies. In the entire patient population, the abducens and facial nerve deficit rates were 5.9% and 5.2%, respectively, and the modified Rankin Scale score significantly decreased from 1.6 ± 1.1 preoperatively to 1.0 ± 1.1 at follow-up. CONCLUSIONS: The authors' results suggest favoring a posterolateral over a posteromedial access route to PCMs in patients in whom a lesion is encountered that can be removed via either surgical approach. In the present series, the authors have found such a constellation in 57% of all patients. This retrospective analysis confirms their hypothesis in a large patient cohort. Additionally, the authors demonstrated that 4 types of PCMs can be distinguished by preoperatively evaluating whether only one reasonable or two alternative surgical approaches are available to access a specific lesion. The rates of postoperative sixth and seventh nerve palsies in this series are substantially lower than those in the majority of other published reports.

Neuroendoscopic Technique for Recurrent Chronic Subdural Hematoma with Small Craniotomy.

AIM: To present a case series describing an endoscopic technique with a small craniotomy for recurrent chronic subdural hematoma (rCSDH) treatment. MATERIAL AND METHODS: A total of 17 patients with rCSDH underwent neuroendoscopic hematoma removal with a small craniotomy under local or general anesthesia. The skin incision of the initial surgery on the convexity of the skull was extended, and a burr hole was created for a small craniotomy. After the removal of the outer membrane and hematoma through a small craniotomy, the hematoma was evacuated with a suction tube using the rigid endoscope. The entire hematoma cavity circumference was irrigated, while septations and trabeculae in the hematoma were cut. After hematoma evacuation, the inner membrane was incised and removed to allow brain expansion. Postoperative follow-up was performed for at least 6 months. RESULTS: The regrowth rate of rCSDH after the neuroendoscopy was 5.9%. One patient with recurrent chronic subdural hematoma regrowth required neuroendoscopy again, but no re-recurrence was observed for the next 6 months. All cases were successfully managed using this technique and the postoperative seizure rate was 23.5%. CONCLUSION: This neuroendoscopic technique with a small craniotomy could be useful for recurrent chronic subdural hematoma because the hematoma and septations can be visualized and evacuated along the entire circumference of the hematoma cavity, and the inner membrane can be torn to allow brain expansion.

Fibrous Meningioma with Skull Invasion.

In patients with meningiomas, the presence of skull invasion is known to be a predictor of aggressive clinical behavior, which may negatively influence patient outcomes. In the present report, we discuss a case of fibrous meningioma with skull invasion. A 42-year-old woman was referred to our department presenting with hyperostosis in the right parietal bone. T1-weighted magnetic resonance imaging with gadolinium enhancement revealed prominent enhancement of the intraosseous lesion and dura mater. Following the removal of the tumor body and bone lesion, we performed immunohistochemical staining for osteopontin (OPN), matrix metalloproteinase- 2 (MMP2), and integrin ß-1 (CD29). The tumor body was immunoreactive for OPN and CD29, but not MMP2, whereas, the bone lesion was immunoreactive for all the three antigens. The present case suggests that OPN, MMP2, and CD29 play key regulatory roles in bone invasion.

Brain metastasis from urachal carcinoma.

BACKGROUND: Urachal carcinoma (UC) is a rare variant of bladder carcinoma. Only seven cases of brain metastasis from UC have been reported in the literature thus far. CASE DESCRIPTION: A 77-year-old female was diagnosed with a brain tumor in her left cerebellum 2 years after she underwent surgery for a primary UC in the bladder. Surgery was performed via a midline suboccipital approach and the tumor was totally removed. The excised lesion was pathologically diagnosed as a metastasis and displayed typical pathological features of urachal adenocarcinoma with abundant mucin mixed with signet ring cells. A recurrence was observed at the site of tumor removal 6 months after surgery, and then, gamma knife radiotherapy was performed to the lesion. CONCLUSION: According to the five previously reported similar cases and our case, tumor removal is the treatment of choice. Routine whole brain radiotherapy is not the best treatment choice; however, local radiotherapy including conventional local radiotherapy or gamma knife radiotherapy could be implemented instead.

Effects of Surgery and Radiotherapy on Recurrent Skull Base Meningiomas: Clinical and Biological Analyses.

We reviewed the medical records of 392 patients who underwent initial surgery for skull base meningiomas between 1983 and 2008. Among them, 32 (8.2%) showed tumor recurrence. Risk factors for recurrence were analyzed clinically and biologically. Recurrent cases were treated with radiotherapy, surgery, or both. In reoperation cases, pathological and biological changes were analyzed and compared between groups with or without radiotherapy. The recurrence rate was statistically high in cases of partial tumor removal and in patients with tumor in the cavernous sinus, tumors with histological WHO (World Health Organization) grade ≥ II or MIB-1 index > 3. The local control rate of postoperative radiotherapy for recurrent cases was 66.7%. Malignant transformation and MIB-1 index elevation was observed more frequently in patients who underwent reoperation after radiotherapy than in the reoperation-only group. Risk factors for recurrence of skull base meningiomas are as follows: (1) partial tumor removal, (2) tumor in the cavernous sinus, (3) histological WHO grade ≥ II, or (4) MIB-1 index > 3. Postoperative radiotherapy might be effective for tumor recurrence. However, the indications for radiotherapy should be carefully considered because postsurgical radiotherapy may increase biological activity, inducing malignant transformation.

Intradural Combined Transpetrosal Approach for Primary Pontine Hemorrhage.

OBJECTIVE: The standard combined transpetrosal approach (CTPA) is fundamentally an epidural approach that has been quite successfully practiced for many decades. However, it has some disadvantages, such as cosmetic problems, difficulties with custom-tailored petrosectomy, and cerebrospinal fluid leakage, as it is a complicated epidural procedure. We describe here a case of primary pontine hemorrhage via intradural CTPA (iCTPA), which is a modified technique of CTPA and includes intradural anterior petrosectomy and partial posterior petrosectomy without mastoidectomy and skeletonization of the sigmoid sinus. METHODS: A 63-year-old woman with primary pontine hemorrhage underwent surgery via iCTPA to improve postoperative functional outcomes. After the temporal craniotomy without mastoidectomy and skeletonization of the sigmoid sinus, Kawase's triangle and Trautmann's triangle were identified from the intradural space. Resection of Kawase's triangle and partial resection of Trautmann's triangle were performed to approach the frontotemporal surface of the pons. The hematoma was irrigated and totally removed after corticotomy on the pons. RESULTS: The postoperative symptoms of the patient improved within 2 weeks without surgical complication. CONCLUSIONS: The intradural approach allows for custom-tailored petrosectomy and is more straightforward than the epidural route, although it can injure the vein of Labbé. Moreover, it can also reduce cosmetic problems and cerebrospinal fluid leakage. iCTPA could provide enough working space for the frontolateral surface of pontine and petroclival lesions without the need for mastoidectomy and skeletonization of the sigmoid sinus.

Autologous bone dust technique for one burr hole surgery to prevent severe skin depression.

OBJECTIVE: One burr hole surgery is a common treatment modality for initial chronic subdural hematoma and stereotactic hematoma surgery, but severe skin depression is often a postoperative complication. We report the autologous bone dust technique, which uses autogenous bone dust generated during burr hole creation to prevent cosmetic deformity. PATIENTS AND METHODS: The autologous bone dust technique was performed for 51 sides on which burr hole surgery was conducted mainly for chronic subdural hematoma and stereotactic hematoma removal. As much bone dust as possible was collected during the burr hole creation and preserved until closure and the burr hole was plugged with the autologous bone dust. The skin depression after surgery was classified as "no or mild" or "severe" by palpating the postoperative scar. The postoperative osteogenesis was evaluated with a bone window or three-dimensional bone computed tomography (CT). RESULTS: The rate of no or mild skin depression was 86.3%. Osteogenesis in the bone window or on three-dimensional bone CT was observed in 88.6% of the cases with no or mild skin depression, whereas no osteogenesis was found in 11.4%. The rate of no or mild skin depression in patients aged greater than 82 years old (74.1%) was significantly lower than that in those aged less than 82 years old (100%). CONCLUSIONS: The autologous bone dust technique is effective in preventing skin depression after one burr hole surgery without using artificial materials.

Contiguous Metastasis of Pulmonary Adenocarcinoma to Meningioma.

BACKGROUND: Metastasis from one tumor into another is known as tumor-to-tumor metastasis. We report a case of a contiguous occurrence of meningioma and brain cancer metastasis. PATIENT: A 91-year-old woman presented with a sudden onset of weakness in her right limbs and gait disturbance. Fourteen years previously, she had a tumor that was suspected to be a meningioma in the left frontal convexity with no change for several years. One year earlier to presentation she was diagnosed with lung carcinoma in the left lower lobe. RESULTS: Magnetic resonance images revealed enlargement of the tumor with perifocal edema. Histologic examination showed a meningioma with contiguous metastatic poorly differentiated adenocarcinoma, as well as a clearly defined border between the two components. The clinical origin of the metastasis was presumed to be from the left lower lobe of the lung. CONCLUSION: Although our case does not strictly fulfill the definition of tumor-to-tumor metastasis, we suggest a contiguous occurrence develops by the same mechanism and may be a subtype of this process. Although previous reports suggested the loss of epithelial cadherin (E-cadherin) expression in the recipient tumor as the cause of contiguous metastasis, E-cadherin expression was positive in our case and did not seem to be involved in the localization of the metastasis.

Neuroendoscopic hematoma removal with a small craniotomy for acute subdural hematoma.

The present study evaluated the safety and effectiveness of neuroendoscopic hematoma removal with a small craniotomy for the treatment of acute subdural hematoma (ASDH). Five patients (4 men and 1 woman) with ASDH underwent neuroendoscopic surgery with a small-size craniotomy between October 2016 and June 2018. The mean age was 87.4 years (range, 82-94). The eligibility criteria were as follows: 1) the presence of symptoms; 2) no moderate or massive brain contusion or edema; and 3) inability to use a large craniotomy because of poor general condition or absence of an anesthesiologist. After performing the small craniotomy, a 4-mm rigid endoscope was inserted and the hematoma was evacuated. Endoscopic surgery was performed under general or local anesthesia. The bleeding origin was a cortical artery in 2 cases, a bridging vein in 2 cases, and unknown in 1 case. The hematoma was completely removed without re-bleeding and the procedure was lifesaving in all cases. Three patients were discharged with independent gait following rehabilitation whereas 2 patients died due to causes unrelated to ASDH. Despite some surgical limitations, neuroendoscopic hematoma evacuation of ASDH is a safe and effective method that minimizes operative complications in some cases. Small craniotomy was sufficient for inserting and maneuvering ordinal neurosurgical instruments. This technique should be considered carefully before surgery in cases of ASDH.

Incidental ethmoidal dural arteriovenous fistula coexisting with a pituitary adenoma exacerbating post-transsphenoidal epistaxis.

A 64 year-old man with pituitary adenoma developed massive epistaxis after an uneventful endoscopic transsphenoidal surgery. Angiography showed extravasation from the sphenopalatine artery, to which embolisation was performed. An incidentally coexisting ethmoidal dural arteriovenous fistula supplied by the ophthalmic artery aberrantly originated from the middle meningeal artery caused increased haemorrhage.

Surgical Treatment for Primary Brainstem Hemorrhage to Improve Postoperative Functional Outcomes.

BACKGROUND: It remains controversial whether primary brainstem hemorrhage (PBH) should be managed conservatively or treated promptly by surgical evacuation of the hematoma. In the present study, we discuss 5 cases of PBH that were treated surgically and the ability of surgical management to improve postoperative functional outcomes. METHODS: The 4 patients with pontine and medullary hemorrhage underwent surgery via the lateral or midline suboccipital and trans-rhomboid fossa approach in the half-sitting position. The patient with a midbrain hemorrhage underwent surgery via the subtemporal approach in the supine lateral position. We analyzed the postoperative functional outcomes 1 week after surgery and the modified Rankin scale scores 6 months after discharge. RESULTS: Three patients with disturbance of consciousness experienced improvement in their level of consciousness. Four patients with hemiparesis improved in motor function. Oculomotor nerve function improved in 2 of 3 cases. Facial nerve function improved in 2 of 2 cases. Spontaneous respiration improved in 1 patient. The postoperative modified Rankin scale scores improved in all 5 cases. CONCLUSIONS: Because of the good results with these 5 patients with PBH, this surgical strategy could be encouraged with exclusion criteria for early initiation of rehabilitation strategies. We hope to increase our number of patients to accumulate further evidence.

Improvement of Respiratory Depression in a Patient with Primary Medullary Hemorrhage Following Removal of Hematoma in the Half-sitting Position.

Primary medullary hemorrhage is a rare event that may result in ataxic respiration. Although it remains controversial whether primary medullary hemorrhage should be managed conservatively or surgically, recent advancements in neuroimaging and microsurgical techniques have shown promise for improving outcomes and prognosis following surgery. The present report discusses the case of a 70-year-old woman admitted to our institution due to sudden-onset nausea and vomiting. The patient underwent surgical removal of a right medullary hematoma for the treatment of daytime respiratory depression and nocturnal apnea while in the half-sitting position. Following surgery, her spontaneous respiration improved, and she was discharged with independent gait. Despite the risk of venous air embolism, accumulating evidence suggests that the half-sitting position is suitable for brainstem surgery because gravity-assisted blood and irrigation drainage from the surgical field allows for cleaner dissection and reduces the need for bipolar coagulation.

Intradural anterior transpetrosal approach.

The standard anterior transpetrosal approach (ATPA) for petroclival lesions is fundamentally an epidural approach and has been practiced for many decades quite successfully. However, this approach has some disadvantages, such as epidural venous bleeding around foramen ovale. We describe here our experience with a modified technique for anterior petrosectomy via an intradural approach that overcomes these disadvantages. Five patients with petroclival lesions underwent surgery via the intradural ATPA. The intraoperative hallmarks are detailed, and surgical results are reported. Total removal of the lesions was achieved in two patients with petroclival meningioma and two patients with pontine cavernoma, whereas subtotal removal was achieved in one patient with petroclival meningioma without significant morbidity. No patient experienced cerebrospinal fluid leakage. The intradural approach is allowed to tailor the extent of anterior petrosectomy to the individually required exposure, and the surgical procedure appeared to be more straightforward than via the epidural route. Caveats encountered with the approach were the temporal basal veins that could be spared as well as identification of the petrous apex due to the lack of familial epidural landmarks. The risk of injury to the temporal bridging veins is higher in this approach than in the epidural approach. Intradural approach is recommended in patients with a large epidural venous route, such as sphenobasal and sphenopetrosal vein. Navigation via bone-window computed tomography is useful to identify the petrous apex.

Treatment of Hyponatremia with Tolvaptan in a Patient after Neurosurgical Treatment of a Pituitary Tumor: Case Report and Review of Literature.

Hyponatremia is a frequent complication following pituitary surgery. We report a case with hyponatremia after surgery of a pituitary adenoma that was successfully treated with tolvaptan. A 68-year-old man with a pituitary tumor presented with mild hyponatremia (133 mEq/L) before surgery. The patient developed hyponatremia (125 mEq) 4 days postsurgery, and 10% sodium chloride was infused. Seven 7 days postsurgery, hyponatremia was improved (132 mEq/L), and tolvaptan 15 mg was given orally as a single dose instead of the 10% sodium chloride infusion. His serum sodium remained within normal limits. The syndrome of inappropriate antidiuretic hormone secretion (SIADH) after pituitary surgery most probably led to the hyponatremia, and tolvaptan was effective because it is an oral vasopressin receptor antagonist.

Executive dysfunction is related with decreased frontal lobe blood flow in patients with subarachnoid haemorrhage.

OBJECTIVE: This study evaluated executive dysfunction in patients with subarachnoid haemorrhage (SAH) using the Behavioural Assessment of the Dysexecutive Syndrome (BADS) and correlated the occurrence of executive dysfunction with cerebral blood flow (CBF) reduction in the frontal lobe as assessed by single photon emission computed tomography (SPECT). DESIGN: Correlational study. SUBJECTS: Twenty-two patients who underwent microsurgical clipping at least 3 months after SAH. METHODS: This study evaluated the BADS and the Wechsler Adult Intelligence Scale-III (WAIS-III). In addition, it assessed activities of daily living (ADL). CBF was evaluated using SPECT. The patients were divided into the following groups according to the results of SPECT: (1) those with reduced CBF in the frontal lobe (reduced CBF group, n = 8) and (2) those with intact CBF (intact CBF group, n = 14). RESULTS: The BADS score was significantly lower in the reduced CBF group compared with that of the intact CBF group, while there was no significant difference in the WAIS-III scores and ADL scale between the two groups. CONCLUSION: Although this result was conducted with a small sample size, executive dysfunction correlates with reduced CBF in the frontal lobes of SAH patients. A detailed evaluation of executive function is suggested in SAH patients, even if the patient's intelligence test and ADL scale reveal no abnormalities.

A case of intraosseous microcystic meningioma without a mass lesion.

Both intraosseous and microcystic meningiomas are rare tumor types. We report the case of a 66-year-old woman with intraosseous microcystic meningioma without a mass lesion. She presented with a rare intraosseous microcystic meningioma manifesting as pain. Radiological examination revealed an osteolytic lesion in the right parietal bone. Magnetic resonance (MR) images showed iso- to hypointensity on T1-weighted images and hyperintensity on T2-weighted images corresponding to the lesion. T1-weighted MR imaging with gadolinium enhancement better defined the marginal area. The inner table of the skull was disrupted prominently, and both sides of the outer table were eroded. There was fluid leakage during surgery but no obvious tumor mass. Histological examination revealed microcystic meningioma in the inner part of the defective bone. A macroscopic lesion was not found, because most of the tumor comprised microcysts, and their contents leaked out during the surgical procedure. Intraosseous microcystic meningioma may be considered as one of the differential diagnoses when the intraosseous tumor in the skull has fluid leakage and does not have a mass lesion during the surgery.

Endovascular revascularization of external carotid artery occlusion causing tongue infarction: case report.

A 62-year-old man with diabetes and a history of ischemic coronary disease visited the emergency department complaining of acute pain and swelling of the tongue. Physical examination found subtle swelling and pallor of the right side of the tongue, and he was initially diagnosed with glossitis. However, his symptoms were progressive, and the tongue had sustained serious tissue damage before the correct diagnosis was established. Digital subtraction angiography of the cervical vessels revealed occlusion of the right external carotid artery (ECA) and lingual artery without collateral circulation to the right side of the tongue from the contralateral ECA or ipsilateral vertebral artery (VA). Endovascular revascularization was performed to restore blood flow to the tongue using balloon angioplasty of the proximal segment of the right ECA followed by deployment of a self-expanding stent. Tongue pain subsided shortly after the procedure, and configuration of the tongue returned to normal 4 months after intervention. Tongue infarction is rare and usually associated with systemic vasculitides. Tongue infarction due to unilateral occlusion of the ECA is extremely rare because of the rich collateral circulation to the tongue from the ipsilateral VA and contralateral ECA. Atherothrombotic unilateral occlusion of the ECA should be included in the differential diagnosis of tongue infarction. Revascularization of the occluded ECA is worth attempting despite substantial tissue damage because of the viability of the tongue muscles and the minimal risk of complications in experienced hands.

Epidural anterior petrosectomy with subdural visualization of sphenobasal vein via the anterior transpetrosal approach--technical case report.

The drainage of the superficial middle cerebral vein (SMCV) is classified into four subtypes. The sphenobasal vein (SBV) drains from the SMCV to the pterygoid venous plexus at the temporal skull base. Epidural procedures in the standard anterior transpetrosal approach (ATPA) may damage the route of the SBV. We report a case in which modified surgical procedures via the ATPA were used to preserve the SBV. A 45-year-old man complained of right facial pain. Magnetic resonance images revealed a right cerebellopontine tumor suggestive of an epidermoid cyst. Right carotid angiography revealed that the SMCV drained into the pterygoid venous plexus via the SBV. The convexity dura mater of the temporal lobe was cut and the anterior part of the temporal lobe was retracted subdurally. The SBV was visualized from the subdural side. The basal dura mater of the temporal lobe posterior to the SBV was cut and the posterior part of the temporal lobe was retracted epidurally. After dissecting the dura mater medial to the greater petrosal nerve and to the edge of the petrous apex, the petrous apex was exposed and drilled out without injuring the SBV. The superior petrous sinus and the tentorium were cut. The tumor compressed the root exit zone of the trigeminal nerve. The tumor was grossly totally removed. The modified ATPA (epidural anterior petrosectomy with subdural visualization of the SBV) is effective in preserving the SBV.