Arteriovenous malformation of the vestibulocochlear nerve.

We describe a rare case of an arteriovenous malformation (AVM) embedded in the vestibulocochlear nerve presenting with subarachnoid hemorrhage (SAH) treated by microsurgical elimination of the main feeding artery and partial nidus volume reduction with no permanent deficits. This 70-year-old woman was incidentally diagnosed 4 years previously with two small unruptured tandem aneurysms (ANs) on the right anterior inferior cerebral artery feeding a small right cerebellopontine angle AVM. The patient was followed conservatively until she developed sudden headache, nausea and vomiting and presented to our outpatient clinic after several days. Magnetic resonance imaging demonstrated findings suggestive of early subacute SAH in the quadrigeminal cistern. A microsurgical flow reduction technique via clipping between the two ANs and partial electrocoagulation of the nidus buried within the eighth cranial nerve provided radiographical devascularization of the ANs with residual AVM shunt flow and no major deficits during the 2.5 year follow-up. This is only the second report of an auditory nerve AVM. In the event of recurrence, reoperation or application of alternative therapies may be considered.

Endoscopic surgery for hemorrhagic pineal cyst following antiplatelet therapy: case report.

Pineal cysts of the third ventricle presenting with acute obstructive hydrocephalus due to internal cystic hemorrhage are a rare clinical entity. The authors report a case of a 61-year-old man taking antiplatelet medication who suffered from a hemorrhagic pineal cyst and was treated with endoscopic surgery. One month prior to treatment, the patient was diagnosed with a brainstem infarction and received clopidogrel in addition to aspirin. A small incidental pineal cyst was concurrently diagnosed using magnetic resonance (MR) imaging which was intended to be followed conservatively. The patient presented with a sudden onset of headache and diplopia. On admission, the neurological examination revealed clouding of consciousness and Parinaud syndrome. Computerized tomography (CT) scans demonstrated a hemorrhagic mass lesion in the posterior third ventricle. The patient underwent emergency external ventricular drainage with staged endoscopic biopsy and third ventriculostomy using a flexible videoscope. Histological examination revealed pineal tissue with necrotic change and no evidence of tumor cells. One year later MR imaging demonstrated no evidence of cystic lesion and a flow void between third ventricle and prepontine cistern. In patients with asymptomatic pineal cysts who are treated with antiplatelet therapy, it is important to be aware of the risk of pineal apoplexy. Endoscopic management can be effective for treatment of hemorrhagic pineal cyst with obstructive hydrocephalus.

Endoscopic third ventriculostomy for hydrocephalus due to unruptured pineal AVM: case report and review of the literature.

INTRODUCTION: Arteriovenous malformations (AVM) are considered to be static congenital lesions; however, a subset may possess dynamic pathophysiological capabilities of growth, regression or other morphological changes with time. We report on an adult patient harboring a pineal AVM who presented with progressive symptoms of obstructive hydrocephalus and was successfully treated by endoscopic third ventriculostomy (ETV). CLINICAL PRESENTATION: This 63-year-old man was incidentally diagnosed 8 years previously with an asymptomatic unruptured pineal AVM and followed conservatively until he developed a progressive impairment in consciousness with gait apraxia and incontinence over a period of 2 months. Magnetic resonance imaging (MRI) revealed obstructive hydrocephalus due to nidal compression at the level of the aqueduct. Treatment by ETV resulted in resolution of neurological deficits and ventriculomegaly without evidence of complications at 18-months follow-up. CONCLUSION: Treatment by ETV in adults with obstructive hydrocephalus due to deep pineal AVMs is a reasonable option in selected cases. A discussion of the pathological mechanisms and therapeutic options for this rare entity is presented.

Hemorrhagic colloid cyst with intraventricular extension.

Colloid cysts of the third ventricle presenting with acute obstructive hydrocephalus due to intracystic and intraventricular hemorrhage are extremely rare. The authors report a case of a 43-year-old man with a hemorrhagic colloid cyst that was treated using endoscopic surgery. A small colloid cyst of the third ventricle was initially diagnosed in the patient, and he was treated conservatively at that time. On admission to the authors' institution he presented with sudden headache onset without neurological deficits. Computed tomography and MRI demonstrated a round hemorrhagic mass lesion in the third ventricle with bilateral intraventricular hemorrhage. Endoscopic resection was performed using a flexible videoscope. Only partial removal of the cyst was performed because of a tough cyst wall with highly viscous, hemorrhagic cystic contents. Histological examination revealed a typical colloid cyst wall and hemorrhage mixed within a mucinous substance. Postoperative serial neuroimaging demonstrated a gradual reduction in the residual cyst size and normalization in the lateral ventricle size.

Neurenteric cyst of the lower clivus.

OBJECTIVE: Neurenteric cysts (NCs) typically arise as benign ventral intradural extramedullary developmental malformations of the spine which contain heterotopic epithelium resembling the intestinal or respiratory tracts. Intracerebral NCs are extremely rare, though the frequency of symptomatic reports and incidental findings is increasing, perhaps because of advances in neuroimaging. Recognition of the unique radiographic and histopathologic features of this entity is of growing importance in the treatment of cysts of the neural axis. We present an unusual case of an NC arising at the lower clivus. CLINICAL PRESENTATION: A 58-year-old man presented with occipitalgia, diplopia, a bilateral hearing deficit, and mild dysphagia. Computed tomography and magnetic resonance imaging demonstrated a 5 x 2 x 3-cm extra-axial cystic midline mass anterior to the brainstem at the lower clivus with posterior cyst wall enhancement. INTERVENTION: The patient underwent a left lateral suboccipital total macroscopic resection of the lesion. Microscopic examination and histopathologic findings were consistent with a diagnosis of NC. CONCLUSION: We describe the clinical presentation, imaging, and histopathologic characteristics, and discuss the diagnosis and surgical treatment of this rare lesion and related pathologic entities. Because of the remote possibility of delayed recurrence, even in cases of apparent total cyst wall removal, long-term serial imaging and a consideration of reoperation for recurrences is advisable.

Development of a quick reference table for setting programmable pressure valves in patients with idiopathic normal pressure hydrocephalus.

Quick and reliable setting of programmable pressure valves (PPVs) is important in the treatment of idiopathic normal pressure hydrocephalus (iNPH), especially for reducing overdrainage complications and related medical costs. A new quick reference table (QRT) was developed for improved PPV control and outcome. Shunt control can be based on the pressure environment in the sitting condition, given as hydrostatic pressure (HP) = intracranial pressure + PPV setting + intraabdominal pressure (IAP). Using this relationship, and estimating HP and IAP from the patient's height and body mass index, respectively, a QRT was designed, consisting of a matrix of the patient's height and weight. The QRT was used to make initial PPV settings in 25 patients with iNPH and the clinical outcomes were evaluated. Postoperative readjustments of the PPV were not necessary in 15 of the 25 patients. At 1 month after operation, the PPV setting was decreased once in 5 patients and increased once in 2 patients. Four of these 7 patients improved after a single readjustment. Three patients required further readjustments. At 3 months after operation, another 3 patients required a single readjustment and all improved after this readjustment. The readjustment rate was 40% and readjustment number was 0.68 times/patient. The mean PPV setting at 1 year after operation was 15.5 +/- 3.9 cmH(2)O. Use of the QRT in non-bedridden iNPH patients results in a low incidence of PPV readjustment.

Spontaneous epidural pneumocephalus.

A 20-year-old male presented with an extremely rare spontaneous epidural pneumocephalus which was successfully treated by a single neurosurgical intervention. The patient had a habit of nose blowing and a 1-year history of progressive headache and nausea. Cranial computed tomography (CT) revealed a 2 x 7 cm right temporo-occipital epidural pneumocephalus with extensive hyperpneumatization of the mastoid cells. Right temporo-occipital craniotomy with a right superficial temporal artery and vein flap repair resulted in radiographic resolution of the pneumocephalus, and he remained neurologically free of symptoms at 1-year follow-up examination. Early identification and monitoring of symptomatic pneumocephalus followed by decompression and prevention of infection via closure of the bone defect can avoid possible serious consequences. The underlying mechanisms may involve a congenital petrous bone defect and a ball-valve effect due to excessive nose blowing in our case.

Remote cerebellar hemorrhage after supratentorial unruptured aneurysmal surgery: report of three cases.

We report three cases of remote cerebellar hemorrhage that developed after supratentorial unruptured aneurysmal surgery. In all cases, digital subtraction angiography was performed before each operation in order to rule out other vascular abnormalities, especially around the operative field or the posterior circulation. In addition, all patients were screened for any previous history of bleeding tendencies or other related medical disorders. Each patient underwent clipping surgery via the pterional approach. Remote cerebellar hemorrhage was identified on post-operative computed tomographic scans. In all cases, there was no evidence of significant associated long-term morbidity. A consideration of the possible pathophysiologic mechanisms underlying these post-operative remote cerebellar hemorrhages and suggested strategies for avoiding such complications are discussed.

Huge arachnoid cyst of the occipital cerebral convexity.

A 68-year-old woman presented with a rare huge right occipital cystic lesion manifesting as progressive left hemiplegia. Cranial computed tomography revealed a 4 x 7 cm right occipital lobe thin-walled cyst with midline shift and compression of the ipsilateral ventricle. The patient underwent a single burr hole operation for cystography and delineation of the cyst anatomy, then a separate right parieto-occipital craniotomy with complete cyst evacuation, corticotomy, and ventriculostomy. The presumptive diagnosis was arachnoid cyst. The symptoms had completely resolved by 4 months after surgery with nearly normal neuroimaging appearance after 7 months. Cystography followed by craniotomy and ventriculostomy may be effective for supratentorial arachnoid cysts.

Transient occipitotemporal subcortical diffusion-weighted magnetic resonance imaging abnormalities associated with status epilepticus. Case report.

A 30-year-old man presented with a generalized seizure manifesting as decreased consciousness. Diffusion-weighted magnetic resonance imaging showed transient areas of high intensity in the gray and subcortical white matter of the left occipital and temporal lobes. The lesions did not reflect the vascular territories. After a period of over 2 weeks, his consciousness level improved associated with reduced intensity of the abnormal areas. These findings suggest that seizure induced reversible cytotoxic and vasogenic edema. Transient diffusion-weighted magnetic resonance imaging abnormalities may be associated with generalized seizures and the intensity may reflect the clinical condition.

Development of a new irrigation sucker for microneurosurgery--technical note.

A new irrigation sucker (Delta Irrigation Sucker) was designed for microneurosurgery. The Delta Irrigation Sucker has a unique trigonal pyramid-shape thumb piece, providing a very stable grip. Irrigation is achieved easily by pushing a small button just behind the pressure-regulating pore. Stable hold of the sucker and easy handling of the irrigation button enable irrigation without unsteadiness of the sucker. The Delta Irrigation Sucker is available in six sizes, with diameters from 1.5 mm to 4.0 mm at 0.5 mm intervals. Irrigation force is provided by a pressure bag, and a normal sterile transfusion set can be used as the irrigation circuit. The Delta Irrigation Sucker was used in 20 cases of clipping for ruptured cerebral aneurysm, five cases of tumor resection, and three cases of anterior clinoidectomy and opening of the internal auditory meatus. Subarachnoid clot was easily removed and the bleeding points were easily confirmed. Irrigation, controlled by natural finger movement, did not cause unsteadiness of the sucker.