[Two Cases of Cervical Epidural Hematoma that Developed during Oral Anti-Platelet Treatment and Achieved Satisfactory Outcomes Following Early Diagnosis and Treatment].

We report two cases of patients who developed cervical epidural hematoma while receiving oral anti-platelet agents and achieved satisfactory outcomes following early diagnosis and treatment. Both patients attained decompression within 12 hours of symptom onset and achieved independent gait at an early stage. Decompression was attained in a shorter amount of time(<6 hours)in case 1, and neurological symptoms rapidly and fully improved immediately following surgery. In contrast, sensory abnormality remained in case 2 despite early decompression(<12 hours.)Although there is a tendency to focus on improving motor function with regards to this condition, we found that the persistence of sensory abnormality affects the patient activities of daily living(ADL)more than expected. Based on these findings, we postulate that the reduction in the time until treatment completion is associated with better functional prognosis in patients who are receiving anti-platelet agents or have advanced motor paralysis.

Trochlear nerve schwannoma with intratumoral hemorrhage presenting with persistent hiccups: a case report.

Trochlear nerve schwannoma without neurofibromatosis is extremely rare. To our knowledge, only 31 surgical cases have been reported to date, and only 2 cases of trochlear nerve schwannoma with intratumoral hemorrhage have been reported. None of those cases presented with persistent hiccups. We report the case of a 44-year-old man with trochlear nerve schwannoma associated with intratumoral hemorrhage who presented with a 10-day history of persistent hiccups. Computed tomography and magnetic resonance imaging revealed a solid tumor with a 3-cm diameter and intratumoral hemorrhage in the left petroclival region that compressed the midbrain and pons. Subtotal removal of the tumor was performed via the zygomatic transpetrosal approach. Intraoperative findings revealed a tumor arising from the trochlear nerve. The histologic diagnosis was schwannoma of Antoni type A cells with intratumoral hemorrhage. Although the patient's left trochlear nerve palsy worsened temporarily, his postoperative course was uneventful. We present this rare case and discuss the mechanism underlying the patient's persistent hiccups.

[Two cases of anterior cerebral artery aneurysm associated with accessory anterior cerebral artery: review of the literature and points of diagnosis].

The accessory anterior cerebral artery (AccACA) is an anomalous vessel arising from the anterior communicating artery. Although AccACA is not particularly rare, aneurysms arising from the AccACA is extremely rare. Here, we report two cases of unruptured AccACA aneurysms. Patient 1 was a 58-year-old woman with an unruptured distal AccACA aneurysm. Magnetic resonance imaging and three-dimensional computed tomography angiography(3D-CTA)demonstrated a left middle cerebral artery aneurysm that was subsequently clipped successfully by direct surgery. No aneurysm was detected in the distal anterior cerebral artery(ACA)due to the narrow imaging range at that time. Postoperatively, an aneurysm of the distal ACA was incidentally identified on 3D-CTA. This AccACA aneurysm was also clipped by direct surgery about 5 months later, and the patient was discharged without any neurological deficits. Patient 2 was a 46-year-old woman with an aneurysm at the proximal portion of the AccACA. Since the aneurysm was small and patient was asymptomatic, the observation-approach was selected. In introducing these cases, we discuss AccACA aneurysms and the process of diagnosis. Aneurysm can arise over the entire length of the ACA, from the anterior communicating artery to the peripheral portion, particularly the supracallosal portion, so observation and imaging of the peripheral region is important in cases where an AccACA is present.

[Contralateral suboccipital approach for clipping of an unruptured vertebral artery-posterior inferior cerebellar artery aneurysm].

Numerous approaches have been used to access aneurysms of the vertebral artery(VA)-posterior inferior cerebellar artery(PICA)complex for microsurgical clipping. Here, we report the case of a patient with an unruptured aneurysm of the left VA-PICA complex that was successfully treated using a contralateral suboccipital approach. Computed tomography angiography demonstrated a small saccular aneurysm arising from the lateral aspect of the left V4 segment just distal to the PICA origin. The aneurysm deviated to the right from the midline at the level of the jugular tubercle on angiographic evaluation, so we selected a contralateral suboccipital approach. The aneurysm was completely obliterated by neck clipping. After surgery, slight dysphagia and hoarseness appeared, but dysphagia disappeared within several days and hoarseness disappeared within 5 months. VA-PICA aneurysms can vary in their relationship to cranial nerves, brainstem, and bones of the skull base. Neurosurgeons should consider using a contralateral approach for certain aneurysms arising from a tortuous VA that has crossed the midline.

A rare case of Chiari type-1 malformation accompanied by symptomatic cerebrospinal fluid hypovolemia: comparison of congenital Chiari type-1 malformation and acquired Chiari malformation secondary to cerebrospinal fluid hypovolemia: case report.

A 23-year-old woman was injured in a rear-end collision. She had general malaise and posterior neck pain, which were more severe when she was in an upright position. Magnetic resonance imaging (MRI) revealed the presence of cerebellar tonsil descensus and syringomyelia in the spinal cord. Radioisotope (RI) cisternography showed signs of an early accumulation of RI in the bladder, and a delayed accumulation of RI in the cerebral fornix. We considered the possibilities of cerebrospinal fluid (CSF) hypovolemia and congenital Chiari type-1 malformation as being responsible for her headache. To obtain a definitive diagnosis, we performed gadolinium (Gd)-enhanced MR cisternography and found evidence of CSF leakage. We performed an epidural blood patch (EBP), and her symptoms resolved. In 2 years since the episode, her symptoms have not recurred, and additional treatment has not been required. In addition, MRI performed 2 years after the EBP did not reveal any changes. There seems no previous report which described successful differentiation of pre-existing congenital Chiari type-1 malformation from the acquired one caused by symptomatic CSF hypovolemia. Because treatment protocols differ between these two conditions, the establishment of a correct diagnosis is important.

[A case of internal carotid artery stenosis with discontinuance of carotid endarterectomy due to the tight adhesions around the internal carotid artery].

A 73-year-old female visited her local doctor after repeatedly experiencing temporary weakness in her left upper and lower extremities. The patient underwent a cervical magnetic resonance imaging (MRI) scan and was diagnosed with right internal carotid artery stenosis. Despite administration of antiplatelet drugs, her symptoms continued, and she was referred to our department for medical treatment. Her medical history revealed hypertension, hyperlipidemia, and cholesteatoma. We diagnosed symptomatic internal carotid artery stenosis and performed carotid endarterectomy (CEA). However, tight adhesions between the carotid artery and surrounding tissue made separation difficult, and surgery had to be discontinued. Some of the extracted adherent tissue consisted of hyalinized fibrous tissue that had the appearance of soft tissue which had organized because of inflammation. Although there have been no reports of cholesteatoma directly causing adhesion around the internal carotid artery, it has been reported to have led to abscess formation in the parapharyngeal space adjacent to the carotid space. Because the boundaries of the parapharyngeal space and carotid space are anatomically incomplete, inflammation often affects the area between them. As far as we know, this report, which also includes a discussion of the literature, is the first to indicate that cholesteatoma causes strong adhesions around the carotid artery.

Trigeminal neuralgia caused by venous compression.

OBJECTIVE: The purpose of this study is to clarify whether venous compression on the trigeminal nerve really causes trigeminal neuralgia or not, and to identify which veins are the offending veins. METHODS: We used microvascular decompression in operations on 121 patients with typical trigeminal neuralgia. We analyzed the intraoperative findings and surgical results in these 121 cases. RESULTS: In 7 of the 121 cases, only the vein was identified as a compressive factor on the trigeminal nerve. In 6 of these 7 cases, single venous compression was found, whereas the remaining case had two offending veins. The transverse pontine vein was most frequently found as the offending vein near Meckel's cave. All patients showed complete relief of trigeminal pain after decompression of the veins, but four of them developed facial numbness after surgery, which tended to be slight and did not require any treatment. CONCLUSION: Our surgical experiences showed that venous compression could cause trigeminal neuralgia by itself and that the transverse pontine vein should be carefully observed because it is most frequently the offending vein.

[Vertebral hemangioma extending into the spinal canal: case report].

A 73-year-old woman was admitted to our hospital presenting slowly progressive hypoesthesia below the 5th thoracic dermatome and spastic paraparesis. Computed tomography (CT) and magnetic resonance imaging (MRI) revealed a mass lesion in the T3 vertebral body extending into the spinal canal. The spinal cord was compressed to the left side and right T3 and T4 nerve roots were encased in the mass lesion. One week after admission, T2-T4 laminectomy was performed to relieve the spinal cord compression. A highly vascularized tumor was observed in the epidural space at T3 and T4 levels. The tumor in the spinal canal was removed. The histopathological diagnosis was cavernous hemangioma. The patient's symptoms improved after the surgery. Asymptomatic vertebral hemangiomas are common, but its extraosseus extension causing neurologic symptoms (compressive vertebral hemangioma) is rare. The clinical symptoms, the radiological features, and the strategies for the treatment of compressive vertebral hemangiomas were discussed.

[A surgical case of hemifacial spasm caused by a tortuous, enlarged, and calcified vertebral artery].

Microvascular decompression (MVD) is an established procedure to treat hemifacial spasm and trigeminal neuralgia. However, this cannot be done in some cases in which ecstatic vertebrobasilar arteries are involved. In these instances, alternative techniques must be used. We encountered a patient with hemifacial spasm caused by a calcified, enlarged, and tortuous vertebral artery. To obtain safe and certain neurovascular decompression of the facial nerve, the tortuous and calcified vertebral artery was surgically repositioned by placing layers of Teflon felt at two regions between the brain stem and the artery. After surgery hemifacial spasm completely disappeared. This method is thought to be a useful option for the treatment of hemifacial spasm caused by a tortuous, enlarged, or calcified vertebral artery.

Effects of single low dose irradiation on subventricular zone cells in juvenile rat brain.

Although the juvenile human brain is relatively radioresistant, irradiation can result in brain growth retardation, progressive mental disturbance, and neurologic abnormalities. As neural stem cells or progenitor cells may be a target of radiation injury and may play an important role in the brain's functional recovery, we examined the effects of whole brain irradiation on these cells in juvenile rat. Six-week-old Wistar rats, where the brain is still growing, were irradiated with single doses of 1, 2, or 3 Gy X-ray. We measured their body and brain weights at 30 or 60 days after irradiation. The chronological changes of the subventricular zone (SVZ) were examined at 6 h, 2, 7, 14, 30, or 60 days after irradiation by immunohistochemistry, specifically looking at the neural stem cells or progenitor cells using anti-nestin antibodies specific for these cells. The rate of brain weight gain of irradiated rats significantly decreased in comparison to controls, although that of body weight gain was similar among them. Multiple apoptotic cells appeared in the SVZ at 6 h after irradiation with simultaneous reduction in nestin-positive cells (69% of the control). The cell levels recovered within a week, with the nestin-positive cells reaching maximal numbers (182%) on Day 14. Nestin-positive cells returned to baseline levels within 30 days (96%) and remained unchanged for the subsequent 60 days. The X-ray dosage did not affect these findings. Our findings revealed that single low dose X-ray administration reversibly affected the levels of neural stem and progenitor cells in the SVZ region. These results suggest that continuous multiple administrations of X-rays in clinical treatment may affect irreversible changes on neural stem or progenitor cells, causing brain growth retardation, or dysfunction.

Two surgical cases of internal carotid-ophthalmic artery aneurysms: special reference to the usefulness of three-dimensional CT angiography.

Three-dimensional computerized tomography angiography (3D-CTA) is a noninvasive tool for the diagnosis of cerebral aneurysms. 3D-CTA is helpful in the evaluation of the configuration of aneurysms and their surrounding vessels and anatomical structures. The aim of this study is to assess the usefulness of 3D-CTA for patients with unruptured internal carotid-ophthalmic artery aneurysms. We pre-operatively obtained surgical simulation images using 3D-CTA and 3D reconstruction and then compared them with magnetic resonance angiography (MRA), conventional cerebral angiography and operative findings in the patients. Two patients with unruptured internal carotid-ophthalmic artery aneurysm were selected. These patients underwent direct neck clipping after the optic canal was unroofed through a combined epidural-subdural approach. The cerebral aneurysm was detected by 3D-CTA, MRA and conventional cerebral angiography in each case. Only by 3D-CTA, however, could we easily detect the relationships among the aneurysm neck, ophthalmic artery and optic canal. Based on this information, direct clipping operations were performed safely without any complications. 3D-CTA is an excellent noninvasive diagnostic method not only for detecting cerebral aneurysms, but also for evaluating the relationships between the aneurysms and surrounding structures.

[A case of a ruptured anterior communicating aneurysm which was originally the smallest of several unruptured aneurysms].

A 64-year-old male suddenly developed headache and nausea. He had been pointed 3 years before out as having an unruptured basilar artery aneurysm and a right middle cerebral artery aneurysm. Computed tomography (CT) revealed diffuse subarachnoid hemorrhage in the basal cistern and bilateral Sylvian and interhemispheric fissures. Hematomas in the anterior horns of the lateral ventricles and third ventricle were also seen. Angiography revealed an anterior communicating artery aneurysm, which, retrospectively, had been recognized as a small dilatation of artery wall 3 years before. An operation was performed and the anterior communicating artery aneurysm was successfully clipped. The intraoperative findings revealed the aneurysm was the ruptured one. The risk of rupture and surgical indication for unruptured small aneurysms are discussed.