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Trochlear nerve (CN-IV) mapping method has not been confirmed to date. The compound muscle action potential (CMAP) of CN-IV cannot be recorded because of the low mapping sensitivity and anatomical characteristics of the superior oblique muscle (SOM). The aim of this study was to evaluate the effectiveness of a novel needle electrode (NNE), for the intraoperative mapping of CN-IV. The NNEs were inserted in the target extraocular muscles in 19 patients. We compared the CMAP amplitude of the NNE with that of the conventional needle electrode (CNE). Furthermore, we investigated the dissimilarity between the CMAP of the CN-IV and other extraocular cranial nerves (ECNs) and the correlation between the readings of the CN-IV mapping and its postoperative functional outcome. The CMAP of CN-IV has been measured in nine patients (47.4%). The CMAP of CN-IV was distinguishable from other ECNs. The CMAP of the NNE was found to be three times higher than that of the CNE. Although the NNE has shown the potential to record the CN-IV’s CMAP, 4 cases ended up having a CN-IV postoperative dysfunction. For the first time, we confirmed the possibility of intraoperative mapping the CN-IV using an NNE inserted into the SOM. The NNE can also be useful for other neurophysiological monitoring methods.

Background Carotid blowout syndrome (CBS) is a rare complication that usually occurs after removal of head and neck tumors. Since transnasal skull base surgery allows a wide exposure of the ventral skull base, neurosurgeons should pay attention to prevent this devastating complication. We present, three cases involving exposure of the internal carotid artery (ICA) at the skull base during the simultaneous transnasal and transcranial approach. Case Description The first patient was a 69-year-old man with a recurrent chordoma. The exposed ICA was covered by an abdominal fat graft and nasoseptal flap, but he experienced CBS 2 months later and died. The second patient was a 66-year-old man with an intraosseous cavernous angioma of the petrous bone. The exposed ICA was covered by a temporoparietal galeal flap (TPGF), abdominal fat graft, and nasoseptal flap. The third patient was a 73-year-old man with skull base radiation necrosis and intracerebral abscess after proton beam therapy for orbital adenoid cystic carcinoma. The exposed ICA was covered by TPGF. The second and third patients' postoperative courses were uneventful. Conclusion Based on our experience, a nasoseptal flap alone may be insufficient to protect ICA. TPGF is therefore another available reconstruction option that may help prevent CBS.

Germ cell tumors typically occur in children and adolescents. We here report a rare case of de novo pineal region germinoma in the seventh decade of life. A 62-year-old man presented with double vision. Computerized tomography and magnetic resonance imaging (MRI) identified a heterogeneously enhanced tumor with calcification in the pineal region with ventricular dilatation due to aqueduct stenosis. The tumor had not been observed at all on MRI obtained 2 years previously. The patient underwent endoscopic biopsy and third ventriculostomy for the obstructive hydrocephalus. The tumor was histopathologically diagnosed as a pure germinoma. The patient underwent radiomonotherapy, resulting in his complete remission, which was confirmed by a series of follow-up MRI studies and hematological examinations. Intracranial germinoma should be considered in the differential diagnosis of pineal region tumors regardless of age, even though the tumor was undetectable on the previous neuroimaging.

Trochlear nerve (CN-IV) mapping method has not been confirmed to date. The compound muscle action potential (CMAP) of CN-IV cannot be recorded because of the low mapping sensitivity and anatomical characteristics of the superior oblique muscle (SOM). The aim of this study was to evaluate the effectiveness of a novel needle electrode (NNE), for the intraoperative mapping of CN-IV.The NNEs were inserted in the target extraocular muscles in 19 patients. We compared the CMAP amplitude of the NNE with that of the conventional needle electrode (CNE). Furthermore, we investigated the dissimilarity between the CMAP of the CN-IV and other extraocular cranial nerves (ECNs) and the correlation between the readings of the CN-IV mapping and its postoperative functional outcome.The CMAP of CN-IV has been measured in nine patients (47.4%). The CMAP of CN-IV was distinguishable from other ECNs. The CMAP of the NNE was found to be three times higher than that of the CNE. Although the NNE has shown the potential to record the CN-IV's CMAP, 4 cases ended up having a CN-IV postoperative dysfunction.For the first time, we confirmed the possibility of intraoperative mapping the CN-IV using an NNE inserted into the SOM. The NNE can also be useful for other neurophysiological monitoring methods.

We report a case of a young male who received multiple surgical treatments for repeated recurrence of skull base mesenchymal chondrosarcoma (MC). When the patient was 18 years old, we subtotally removed the skull base MC and he was treated with stereotactic radiosurgery for remnant tumors in the left cavernous sinus. After 30 months, we removed residual tumors that had regrown partially, via combined endonasal endoscopic and orbitozygomatic approaches. Over the next 65 months, the patient refused radical resection, and received six salvage surgeries, two stereotactic radiotherapies, and five stereotactic radiosurgeries for repeated recurrence. At 95 months after initial surgery, the tumors had extended to the skull base and nasal cavities. As a result, the left eye had been blinded and right visual acuity was deteriorated. We performed left anterior-middle cranial base resection, removal of nasal and intradural tumors, high flow bypass, en-bloc resection of the left cavernous sinus and clivus, and reconstruction using an abdominal flap. Even though the main tumors were removed with safety margins, tumors around the right optic nerve were removed by piecemeal to preserve right eye function. Six months after the radical resection, tumors in the right orbital apex recurred because we had been unable to remove the tumor with adequate safety margins. Skull base MC has a high tendency to recur locally, so these tumors should be radically removed with safety margins as early as possible to prevent recurrence.

Objectives Leptomeningeal metastasis (LM) is associated with poor prognosis and affects the quality of life (QOL) of end-stage cancer patients. Severe headache associated with hydrocephalus causes reduced QOL. We investigated the clinical value of surgical treatment for hydrocephalus in LM patients. Patients and methods The medical records of 11 consecutive patients who underwent lumboperitoneal shunt (LPS) or ventriculoperitoneal shunt (VPS) at our institution between 2007 and 2016 were investigated. Primary brain tumor patients were excluded. We assessed the neurological status and therapeutic effects at 1 month after the shunt surgery. Results The patients were three males and eight females with a median age of 58 years (interquartile range [IR] 52–68 years). The median preoperative neutrophil-to-lymphocyte ratio was 6.4 (IR 4.8–9.2). Symptom improvement was observed in nine patients, and severe headache was relieved in seven (88%) out of eight patients. The median Karnofsky performance status scale increased from 40 to 60, and the median overall survival after primary malignancy diagnosis was 27.4 months (IR 19.6–63.1 months). The median survival after the diagnosis of brain parenchymal metastasis, LM, and shunt surgery were 7.2 months (IR 5.1–14.1 months), 3.9 months (IR 3.5–6.3 months), and 3.3 months (IR 2.9–5.7 months), respectively. Conclusion Shunt surgery for hydrocephalus could offer an effective palliative surgical option for symptom relief especially relief of severe headache, contributing improvement of QOL in LM patients.

We investigated whether acromegaly has been diagnosed earlier at the Niigata Medical and Dental University Hospital.Patients with acromegaly (n = 81) who underwent their first transsphenoidal surgery from 2006 to 2015 were reviewed. Two groups were compared: those who underwent surgery between 2006 and 2010 (n = 35) and those who underwent surgery between 2011 and 2015 (n = 46). We compared clinical features and serum levels of the growth hormone (GH) and insulin-like growth factor-1 (IGF-1), hypertension (HT) and diabetes mellitus (DM) prevalence between the two groups.Compared with the early group, microadenomas (10 mm) were more prevalent in the late group (0% vs. 15.2%, p .05). Serum IGF-1 standard deviation score (SDS) was significantly lower in the late group (8.57 ± 2.50 vs. 6.44 ± 2.30, p .001). In both groups, mean IGF-1 SDS was significantly lower in patients without DM than in those with DM (6.9 ± 2.6 vs. 8.3 ± 2.4, p = .02). Logistic regression analysis showed that serum GH and IGF-1 levels were significantly higher in patients with DM than in those without DM.Regarding operated cases of GH-producing pituitary adenoma, acromegaly clinical manifestations tended to be milder at diagnosis in later years of the decade, and acromegaly was diagnosed at lower IGF-1 levels and in smaller lesions. Further study is mandatory for the generalization of this trend.

Double functional pituitary adenomas are rare, and only a few cases of excessive clinical symptoms of both adrenocorticotropic hormone(ACTH)and growth hormone(GH)have been reported. We herein report a case of symptomatic ACTH-and GH-producing double pituitary adenomas, which were discretely located within the same pituitary gland. A 38-year-old woman presented with general malaise, facial and lower limb edema, unexplained weight gain, facial redness, acne, and nasal enlargement. Endocrinological findings matched with the diagnostic criteria for both acromegaly and Cushing's disease. Preoperative magnetic resonance imaging showed a 15-mm cyst-like lesion on the right side of the sellae surrounded by what was thought to be the normal contrast-enhancing pituitary gland. We assumed that the cyst-like lesion was an adenoma and performed endoscopic endonasal transsphenoidal surgery. However, the cyst-like lesion was a parenchymal tumor. Furthermore, the region we considered to be a normal pituitary gland was also found to be an adenoma. Both adenomas were completely resected. The postoperative blood analysis showed ACTH1.0pg/dL, cortisol 1.8μg/dL, and insulin-like growth factor-1 60ng/mL, all of which were below reference levels. The histopathological examination confirmed the coexistence of two adenomas, a GH-producing adenoma and an ACTH-producing adenoma. We concluded that these adenomas were endocrinologically active within the pituitary gland. Thus, a diagnosis of double pituitary adenomas was made. When treating a patient with symptoms caused by hypersecretion of multiple anterior pituitary hormones, the possibility of coexisting multiple pituitary adenomas should be considered.

Spontaneous cerebrospinal fluid(CSF)rhinorrhea may have multiple leakage sites, and occasionally, may become difficult to manage. A 46-year-old man was admitted to our hospital presenting with bacterial meningitis that occurred after CSF rhinorrhea. The CSF leak had stopped following conservative medical treatment;however, it recurred immediately. The leakage was assumed to be in the left lateral recess of the sphenoid sinus based on the location of fluid accumulation on the CT and MR images and the nasal endoscopic findings. First, we performed an endoscopic endonasal repair of the CSF leakage sites. There were multiple defects in the roof of the sphenoid sinus, including the left lateral sphenoid recess. These bone defects were repaired with abdominal fat;however, this did not stop the CSF leak. Therefore, he underwent a craniotomy and nasal endoscopy, which were performed simultaneously using a galeal flap. The galeal flap was inserted from the middle of the skull base to the sphenoid sinus to cover the bone defects, and the position was adjusted under the guidance of nasal endoscopy. Moreover, intraoperatively, another meningocele with CSF leak was discovered in the cribriform plate and was repaired using abdominal fat. The CSF leak stopped after the second surgery. It is important to be mindful of possible multiple leakage sites when treating cases of idiopathic CSF leakage;moreover, the determination of the leakage sites can be difficult. A repair surgery using a galeal flap is preferable in cases of multiple CSF leakage sites, such as in this case, because it allows for all defects to be covered and repaired simultaneously.

OBJECTIVEAlthough sphenoidotomy is more commonly performed via the transnasal approach than via the transcranial approach, transcranial sphenoidotomy (TCS) remains indispensable for en bloc resection of locally advanced sinonasal malignant tumors (SNMTs) extending to the skull base. TCS also enables transsphenoidal transposition of the temporoparietal galeal flap (TPGF) to compensate for the lack of vascularized reconstructive tissue after endoscopic transnasal skull base surgery. The objective of this study was to review the authors’ surgical experience using TCS with an emphasis on the surgical anatomy of the sphenoid sinus and on the purpose of TCS. Relevant anatomy is further illustrated through cadaveric dissection and photo documentation.METHODSThe authors reviewed the records of 50 patients who underwent TCS at the Nagoya University Hospital, Fukushima Medical University Hospital, or Aichi Medical University Hospital over the course of 7 years (between January 2011 and November 2017). The authors also performed cadaveric dissection in 2 adult cadaveric skull base specimens.RESULTSOf the 50 patients included in this study, 44 underwent craniofacial resection (CFR) for en bloc resection of SNMTs involving the anterior and/or lateral skull base, and 6 underwent transsphenoidal transposition of the TPGF flap. The authors categorized the TCS procedures according to the portion of the sphenoid sinus wall involved (i.e., superior, lateral, and superolateral). Superior sphenoidotomy was used in patients requiring anterior CFR. Lateral sphenoidotomy was further divided into 2 subtypes, with type 1 procedures performed for the transsphenoidal transpositioning of the TPGF, and type 2 procedures used in patients requiring lateral CFR. Superolateral sphenoidotomy was used in anterolateral CFR.CONCLUSIONSTCS still represents a useful tool in the armamentarium of neurosurgeons treating central skull base lesions. The newly proposed surgical classification facilitates a profound understanding of TCS and how to incorporate this technique into clinical practice.

Background: Sinking skin flap syndrome or paradoxical brain herniation is an uncommon neurosurgical complication, which usually occurs in the chronic phase after decompressive craniectomy. We report a unique case presenting with these complications immediately after decompressive craniectomy for severe traumatic brain injury. Case Description: A 65-year-old man had a right acute subdural hematoma (SDH), contusion of the right temporal lobe, and diffuse traumatic subarachnoid hemorrhage with midline shift to the left side. He underwent an emergency evacuation of the right SDH with a right decompressive frontotemporal craniectomy. Immediately after the operation, his neurological and computed tomography (CT) findings had improved. However, within 1 h after the surgery, his neurological signs deteriorated. An additional follow-up CT showed a marked midline shift to the left, i.e., paradoxical brain herniation, and his skin flap overlying the decompressive site was markedly sunken. We immediately performed an urgent cranioplasty with the right temporal lobectomy. He responded well to the procedure. We suspected that a cerebrospinal fluid leak had caused this phenomenon. Conclusion: Decompressive craniectomy for severe traumatic brain injury can lead to sinking skin flap syndrome and/or paradoxical brain herniation even in the acute phase. We believe that immediate cranioplasty allows the reversal of such neurosurgical complications.

Background Lower cranial nerve sheath tumors are relatively rare. Cases of schwannoma collision tumors have rarely been reported, with most of the reported cases describing schwannoma and meningioma collision tumors. Case Description We report a very rare case of a cerebellopontine angle collision tumor of the ninth cranial nerve schwannoma with an IgG4 plasma cell pseudotumor. IgG4 plasma cell pseudotumors comprise a group of diseases called IgG4-related diseases (IgG4-RDs). These diseases usually affect organs such as the pancreas and salivary gland. Few cases of nervous system IgG4-RDs have been reported. Under intraoperative microscopy, the tumor in our case did not appear different from usual cases of schwannoma, but histopathology showed significant infiltration of IgG4 plasma cells. Conclusion IgG4-RDs have a distinctive histopathologic pattern; however, their pathophysiology remains unclear. Special attention must be paid to the diagnosis of such diseases because they mimic other diseases and can be missed.

We report a rare case of primary pituitary lymphoma in a 75-year-old immunocompetent woman. The patient was blind in the right eye and presented with visual disturbance in the left eye that started 2 months previously. She also exhibited right third and fifth cranial nerve palsy. Magnetic resonance imaging(MRI)revealed an intrasellar mass lesion with right cavernous sinus invasion and suprasellar extension with compression of the optic chiasm. The mass lesion was isointense on both T1WI and T2WI, and showed less enhancement than a normal pituitary gland on gadolinium-enhanced T1WI. We therefore suspected the tumor to be a nonfunctioning pituitary adenoma. The patient underwent endoscopic endonasal transsphenoidal surgery. The tumor was firm and grayish, and had an ill-defined border along the normal pituitary gland. Histological examination revealed a malignant CD5-positive diffuse large B-cell lymphoma. After surgery, the patient received both chemotherapy and radiotherapy. Although the visual acuity of the right eye did not improved, other symptoms improved. At the 34-month follow-up, no recurrence was detected on serial MRI. Patients with primary pituitary lymphoma often exhibit ophthalmoplegia and/or panhypopituitarism more frequently than expected from radiological findings. In cases of pituitary tumors with atypical symptoms, a biopsy and general physical examination should be performed immediately to determine the diagnosis and perform adjuvant therapy even when the tumor is assumed as nonfunctioning pituitary adenoma from the image findings.

For pineal nongerminomatous malignant germ cell tumors (NGMGCTs), we mainly performed radical tumor resection during initial treatment combined with adjuvant therapy. We retrospectively analyzed 17 patients treated for pineal NGMGCTs between 1986 and 2007 at the University of Niigata. Twelve patients underwent total or subtotal resection of their tumor via the occipital transtentorial approach. Five patients underwent partial resection, and four of them later underwent total resection by salvage surgery. After surgery, eight patients were treated with combined radiochemotherapy including whole-brain irradiation, two received radiation monotherapy, one had chemotherapy with local irradiation, and six were treated with chemotherapy alone. The median follow-up period for surviving patients was 179 months. The 10-year overall survival and progression-free survival rates for the radiochemotherapy group were both 75.0 % (two patients had a recurrence and died); the rates for other adjuvant therapies were 77.8 % (two died) and 22.2 % (seven had a recurrence), respectively. Radiochemotherapy was significantly associated with an increased rate of progression-free survival compared with the other adjuvant therapies (p = 0.0396). For pineal NGMGCTs, initial treatment strategies including gross total resection of the tumor before or after whole-brain irradiation and chemotherapy provided good therapeutic outcomes. Obtaining complete remission of the primary tumor, irrespective of the timing of surgical resection (i.e., before or after adjuvant therapies), or complete response by neoadjuvant radiochemotherapy during an initial treatment appears to be essential for improving therapeutic outcomes of intracranial NGMGCTs.