Comparison of the Degree of Expanded Spinal Canal Area between the Hinge-Side Area and the Open-Side Area in Cervical Open-Door Laminoplasty.

Background: There have been reports on the significant canal cross-sectional area (CSA) expansion difference between pre- and post-operation, but no comparison of CSA expansion between the hinge-side area (Area H) and the open-side area (Area O) has been reported. This study aimed to measure the spinal CSA expansion between Area H and Area O retrospectively after open-door laminoplasty using new titanium spacers and evaluated this common decompression procedure's effectiveness. Materials and Methods: This study included 27 patients diagnosed with cervical spondylotic radiculopathy or myelopathy, ossification of the posterior longitudinal ligament, and developmental canal stenosis from February 2021 to October 2022. The CSA difference between pre- and post-cervical laminoplasty (C4-C6 levels) was measured with cervical transverse computed tomography scan images. The CSA difference in Area H and Area O between pre- and post-laminoplasty was similarly calculated. Results: The spinal canal areas of each segment after open-door laminoplasty were significantly enlarged (P < 0.05). Area O was also significantly enlarged compared to that of Area H (P < 0.05). Conclusion: Area O was more enlarged than Area H, and both sides were statistically enlarged after open-door laminoplasty.

Risk Factors of Subsidence after Anterior Cervical Discectomy and Fusion with Double Cylindrical Cages for Cervical Degenerative Diseases: Minimum Two-year Follow-up Results.

Cylindrical cages were known to cause subsidence after anterior cervical discectomy and fusion (ACDF); hence, they were gradually replaced by box-shaped cages. However, this phenomenon has been inconclusive due to limited information and short-term results. Therefore, this study aimed to clarify risk factors for subsidence after ACDF using titanium double cylindrical cages with mid-term follow-up periods. This retrospective study included 49 patients (76 segments) diagnosed with cervical radiculopathy or myelopathy caused by disc herniation, spondylosis, and ossification of the posterior longitudinal ligament. These patients underwent ACDF using these cages from January 2016 to March 2020 in a single institution. Patient demographics and neurological outcomes were also examined. Subsidence was defined as a ≥3-mm segmental disc height decrease at the final follow-up lateral X-ray compared to that on the next day postoperatively. Subsidence occurred in 26 of 76 segments (34.7%) within the follow-up periods of approximately three years. Multivariate analysis using a logistic regression model demonstrated that multilevel surgery was significantly associated with subsidence. The majority of patients achieved good clinical outcomes based on the Odom criteria. This study demonstrated that multilevel surgery was the only risk factor of subsidence post-ACDF with double cylindrical cages. Despite the relatively high subsidence rates, the clinical outcome was almost good at least during the mid-term period.

A case of meningioma originating from the lateral wall of the cavernous sinus.

Meningioma originating from the lateral wall of the cavernous sinus is rare with only two reported cases. A 67-year-old man presented with recent memory disturbance and partial seizure. Magnetic resonance imaging revealed a well-demarcated and homogeneously enhanced mass lesion originating from the lateral wall of the left cavernous sinus. Total tumor removal was performed through a combined epi- and intradural approach. Histological diagnosis was transitional meningioma. Postoperative course was uneventful. This combined approach was helpful for cranial nerve preservation, total tumor removal, and bleeding control from the feeder of the tumor.

Mixed pial and dural arteriovenous fistula after craniotomy: case report and literature review.

Dural arteriovenous fistula (AVF) is known to occur after craniotomy, but mixed pial and dural AVF after craniotomy has not been reported. A 45-year-old man who had undergone surgical clipping of an unruptured aneurysm 2 years previously presented with small subcortical hemorrhage from mixed pial and dural AVF. Surgical disconnection could not be cured completely due to the granulomatous tissue around the aneurysm, and the presence of an undetected shunt. Postoperative digital subtraction angiography showed a new pial AVF supplied by the middle cerebral artery pial branches. Many branches were associated with the remnant aneurysm and pial AVF, so we did not try to embolize the fistula. Gamma knife surgery was performed as adjuvant radiotherapy, which achieved angiographically complete occlusion of the shunt points. Multimodal approaches including surgery, endovascular intervention, and radiotherapy are needed for radiological and clinical cure of mixed pial and dural AVF. Long-term follow up is essential.

Cervical Transverse Myelitis Following COVID-19 Vaccination.

Various COVID-19 vaccines are associated with numerous adverse side effects. Associations between vaccinations and neurological disorders, such as transverse myelitis, stroke, Bell's palsy, acute disseminated encephalomyelitis, and Guillain-Barré syndrome, have been reported. A 27-year-old Japanese woman presented with paresthesia four days after receiving a second dose of the COVID-19 vaccine. One month after vaccination, she started to feel left lower limb weakness, and her symptoms almost improved after two steroid pulse therapies. Spinal cord tumor biopsy could potentially help make a definitive diagnosis in clinical situations. However, it is very important to review the patient's medical history, including vaccinations received, before performing a direct spinal cord biopsy, which is invasive and does not guarantee a definitive diagnosis.

[A Case Report of Brain Metastasis from Anal Canal Carcinoma].

A 55-year-old female with adenocarcinoma of anal canal(stage IV with lung, bone, and lymph node metastasis)underwent total pelvic exenteration surgery and chemotherapy. Chemotherapy was continued after the surgery. One month later, she presented to the emergency room with gait disorder and cognitive dysfunction. CT and MRI demonstrated metastatic brain tumor in the right cerebellar hemisphere. Craniotomy and CyberKnife surgery were performed. Histological examination revealed adenocarcinoma with atypical cells forming a papillary arrangement. She died 35 weeks after the surgery. Brain metastasis from anal carcinoma is very rare, but recent advances in chemotherapy are achieving favorable results of long-term survival, and this is likely to increase in the future. Early detection, early treatment, and combined therapy may improve the long-term outcome for patients.

A Case of Meningioma Originating from the Oculomotor Nerve.

BACKGROUND: Schwannoma originating from the oculomotor nerve has been reported. However, meningioma originating from this nerve was unknown. CASE DESCRIPTION: A 22-year-old woman presented with a unique case of meningioma originating from the oculomotor nerve manifesting as periorbital pain and diplopia beginning 4 months previously. Oculomotor nerve schwannoma was suggested by several pretreatment examinations. Tumor resection was considered risky for preservation of the oculomotor nerve function; therefore, gamma knife surgery (GKS) was performed. Six months later, she suffered right complete ptosis and worsened blurry vision. Corticosteroid was administered, but her symptoms did not improve. Magnetic resonance imaging showed the tumor lesion had grown larger. We decided to resect the tumor lesion because of her uncontrolled periorbital pain. The tumor had occupied the oculomotor cistern and was gross totally removed. Histologic diagnosis was surprisingly transitional meningioma. The tumor lesion occupied the oculomotor cistern and was refractory to GKS, with a progressive clinical course, which is more suggestive of meningioma than schwannoma, although extremely rare. Her periorbital pain and blurry vision gradually regressed, whereas complete oculomotor nerve palsy persisted. CONCLUSIONS: In such a case, tumor resection after GKS should be considered.

[A Case of Primary Intracranial Malignant Melanoma Mimicking a Traumatic Brain Contusion].

Primary intracranial malignant melanoma(PIMM)is a rare neoplasm of the central nervous system, accounting for 1% of cases of malignant melanomas and 0.1% of cases of brain tumors. Here, we report a case of PIMM that was initially considered to be a traumatic brain contusion. A 44-year-old man was transferred to a local hospital because of general tonic convulsion after falling while riding a bike. CT showed an irregular high-density area in the left temporal pole, which was diagnosed as a traumatic contusion. MRI performed 3 months after the initial episode revealed an enlarged temporal lesion with surrounding edema, suggestive of a neoplasm. The MRI showed the lesion as mixed signal intensity, suggesting both solid and cystic components. Subtotal resection was performed, except for the tumor adhering to the peripheral middle cerebral arteries(MCAs). The definitive diagnosis was made based on pathological findings and no evidence of extracranial lesions. Gamma knife surgery was performed for the remnant tumor adjacent to MCAs. The radiologically positive tumor chronologically regressed, and the patient remained progression-free for 18 months. Radiological findings of PIMM vary but typically include high density on CT and hyperintensity on T1-weighted MRI. Close observation enabled early diagnosis based on the suspicion of a neoplasm according to atypical radiological findings. PIMM has a poor prognosis with an overall survival of 12.0 months without confirmative treatment. Gamma knife surgery might achieve suppression of this highly progressive tumor.

[Hemifacial Spasm Caused by Vertebral Artery Fusiform Aneurysm and the Anterior Inferior Cerebellar Artery].

We report a case of hemifacial spasm in which the root exit zone(REZ)of the facial nerve was compressed by both the vertebral artery(VA)aneurysm and the anterior interior cerebellar artery(AICA). A 60-year-old female had suffered left hemifacial spasm for 2 years. Three-dimensional rotational angiography with selective arterial infusion of contrast medium(3DRA-IA)revealed that a distal part of the left AICA looping at the cisternal region was contacting the dome of the left VA aneurysm, although other imaging modalities did not show the exact course of the ipsilateral AICA. Constructive interference steady state magnetic resonance imaging revealed that both the left VA aneurysm and the left AICA had compressed the REZ of the left facial nerve. She underwent aneurysm clipping and decompression of the REZ by transposition of both the clipped aneurysm and the AICA using TachoSil®. Her hemifacial spasm disappeared immediately after surgery without complication. Some fine arteries might compress the REZ in patients with hemifacial spasm associated with VA aneurysms. 3DRA-IA was more effective for accurate evaluation than other imaging modalities. Transposition of vascular structures using TachoSil® is safe and effective for microvascular decompression surgery in such complicated cases.

[Three Surgical Cases of Brain Metastasis from Renal Cell Carcinoma Occurring more than 10 years after Nephrectomy:Case Reports and Literature Review].

Renal cell carcinoma(RCC)can metastasize to the brain within several years;however, 20 cases of brain metastases have been reported after>10 years of the initial nephrectomy. Here, we report three cases of brain metastasis that occurred>10 years after nephrectomy for RCC. In general, RCC is radio-resistant, but stereotactic radiosurgery has been reported to be effective in some cases. To improve the functional and survival prognoses, delayed brain metastases from RCC should be aggressively resected.

Spontaneous Regression of Germinomas After Salvage Surgery and Possible Mechanism of Induced Apoptosis.

BACKGROUND: A few cases of spontaneous regression of germ cell tumors have been reported. Possible mechanisms include steroid medication, surgical intervention, diagnostic radiation exposure, and immune response. None of these hypotheses has been supported by sufficient data. CASE DESCRIPTION: Two cases of germinoma demonstrated spontaneous regression before antitumor therapy. In the first case, a 19-year-old man presented with acute hydrocephalus due to a pineal mass and underwent emergent endoscopic third ventriculostomy. The pineal tumor started to regress on the 4th postoperative day after endoscopic third ventriculostomy. In the second case, a 22-year-old man presented with acute hydrocephalus and panhypopituitarism due to a suprasellar mass and underwent emergent external ventricular drainage, biopsy, and septostomy on the day of admission. Apparent regression of the tumor was discovered on the 5th day after initial surgery. Pathologic diagnosis was pure germinoma in both cases. Remarkable accumulations of CD4-positive lymphocytes and some apoptotic cells positive for terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling staining were detected in both cases. Diagnostic radiation exposure is the only common condition in all reported cases. CONCLUSIONS: This unusual phenomenon of spontaneous regression of germinoma may be caused by a combination of pathognomonic characteristics of anatomic location with paraventricular development and stress induction as a trigger, such as salvage surgery or diagnostic radiation, including at extremely low dosage.

A new type of hyperplastic anterior choroidal artery.

Hyperplastic anomaly of the anterior choroidal artery (hyperplastic AchA) and posterior communicating artery of duplicate origin (duplicated Pcom) are rare vessel anomalies. With some literature review, we here report three cases of hyperplastic AchA, one of which was considered a new type of hyperplastic AchA. This case was not categorized into Takahashi classification.

[Surgical Treatment for Traumatic Acute Subdural Hemorrhage in the Posterior Cranial Fossa:Three Cases Reports and Review of the Literature].

Acute subdural hemorrhage(ASDH)in the posterior cranial fossa is rare. Extremely unfavorable outcomes are reported among cases accompanied by supratentorial hematoma, brainstem contusion, or intracerebellar contusion. We report three cases surgically evacuated several times for traumatic ASDH in the posterior cranial fossa simultaneously accompanied by supratentorial hematomas. In our three presented cases, the mean age was 72.3 years, and all patients were male. The mechanisms of injury included traffic accidents in two cases and fall in one. The median Glasgow Coma Scale score on admission was 6. On admission, the patients had traumatic ASDH in the posterior cranial fossa accompanied by supratentorial hematoma, so they first underwent external decompression or ICP sensor insertion for the supratentorial lesions. However, after their first surgery, all patients developed upward herniation, and subsequently underwent suboccipital craniotomy and evacuation of hematomas. Glasgow Outcome Scales were death in one case, persistent vegetable state in one case, and severe disability in one case. The patients with ASDH in the posterior cranial fossa accompanied by supratentorial hematoma should immediately undergo suboccipital craniotomy and supratentorial decompression simultaneously when the hematomas compress the brainstem and upward herniation develops.

[Surgical Treatment of a Giant Olfactory Groove Schwannoma:A Case Report].

Schwannomas originating from the olfactory nerve are extremely rare because the olfactory nerve does not normally contain Schwann cells. We describe a case of a giant schwannoma of the olfactory groove. A 73-year-old woman presented with anosmia persisting for 10 months. Head computed tomography(CT)for head trauma at another hospital demonstrated a tumor lesion located in the left frontal lobe and paranasal sinus. She had never suffered epilepsy, and past medical history and family history identified no indicators. Neurological examination revealed anosmia and dementia. Head CT demonstrated a tumor lesion with bone erosion, causing a defect of about 5cm in the frontal base. Head magnetic resonance(MR)imaging with contrast medium indicated a lesion that was 6cm in diameter, with heterogeneous enhancement and severe perifocal edema in the left frontal base, extending into the paranasal cavity. The tumor was resected through a left extradural subfrontal approach with bicoronal frontal craniotomy. The endoscopic approach was also performed simultaneously to remove the tumor in the paranasal sinus. The cystic tumor was soft and easy to bleed. Intraoperatively the right olfactory nerve was confirmed, but the left olfactory nerve could not be identified because of replacement by the tumor, suggesting that the tumor had originated from the left olfactory nerve. The defect of the dura was repaired with femoral fascia, the pedunculated periosteal flap was laid over the frontal base, and the bone defect was repaired with the inner plate of the frontal calvaria. Postoperative head MR imaging with contrast medium revealed no residual lesion. The patient was discharged 25 days after surgery, without new neurological deficits. Histological examination identified mixed Antoni type A and Antoni type B schwannoma on hematoxylin and eosin staining and S-100 protein on immunostaining.