Hiroshi Karibe

Intrinsic arteriovenous malformation of the trigeminal nerve in a patient with trigeminal neuralgia: case report.

OBJECTIVE AND IMPORTANCE:Intrinsic arteriovenous malformation (AVM) of the trigeminal nerve is extremely uncommon and may be associated with trigeminal neuralgia. CLINICAL PRESENTATION:A 55-year-old man experienced severe lightning pain in the second and third divisions of the left trigeminal nerve territory. Vertebral angiography demonstrated an AVM fed by the superior cerebellar artery. Magnetic resonance imaging with three-dimensional spoiled gradient recalled acquisition at steady state revealed an AVM intrinsic to the left trigeminal nerve and a small arterial loop causing compression at the root entry zone of the trigeminal nerve. INTERVENTION:Intraoperative inspection revealed an indentation of the root entry zone caused by a small arterial loop but not by the AVM. The offending artery was displaced to decompress the root entry zone using a prosthesis without resection of the AVM. The patient was relieved of the neuralgia immediately after surgery without further neurological deficit. He has been free of trigeminal neuralgia during a follow-up period of 2 years and is scheduled to undergo stereotactic radiosurgery for the treatment of the AVM. CONCLUSION:Intrinsic AVM of the trigeminal nerve may cause trigeminal neuralgia. However, as in the present case, a coexistent vascular lesion rather than the intrinsic AVM could be a cause of the neuralgia.

Hepatitis C virus (HCV) infection as a risk factor for spontaneous intracerebral hemorrhage: hospital based case-control study

Hepatitis C Virus (HCV) infection was investigated as a risk factor for intracerebral hemorrhage (ICH) by HCV antibody screening in 462 patients with ICH and 462 control patients with cerebral infarction matched by age and sex. Laboratory examinations of hemostatic parameters and cholesterol level were also performed in patients with ICH. HCV infection was significantly more frequent in patients with ICH than controls (8.7% vs 3.5%, P< 0.01). ICH patients with HCV infection had significantly higher L-alanine:2-oxoglutarate aminotransferase level (P< 0.001), lower cholesterol level (P< 0.05), lower platelet count (P< 0.05), and longer prothrombin time (P< 0.01) than ICH patients without HCV infection, although most of these values were within the normal range. These results demonstrate that HCV infection is a risk factor for spontaneous ICH. Subclinical clotting disorder and/or vessel wall friability resulting from hypocholesteremia may be associated with ICH in patients with HCV infection.

Preoperative visualization of microvascular compression of cranial nerve IX using constructive interference in steady state magnetic resonance imaging in glossopharyngeal neuralgia

We report a case of successfully treated glossopharyngeal neuralgia, in whom preoperative magnetic resonance imaging (MRI) with a sequence of constructive interference in steady-state (CISS) precisely delineated microvascular compression to the glossopharyngeal nerve at its cisternal portion. A 70-year old female experienced paroxysmal and excruciating pain, starting in the right ear and descending to the tongue and throat. The pain was brief, burning and triggered by swallowing food and drinks. Preoperative CISS-MRI delineated a small vascular loop compressing the glossopharyngeal nerve at its cisternal portion. The patient was diagnosed with glossopharyngeal neuralgia, and then, microvascular decompression surgery was performed. Intraoperative inspection revealed that the glossopharyngeal nerve root was in contact with a small arterial loop at its cisternal portion and was deformed as demonstrated by preoperative CISS-MRI. The glossopharyngeal nerve was displaced using a piece of Teflon felt, freeing it from the arterial loop compression. The patients neuralgia resolved immediately after surgery. During a period of 2-years follow up, no recurrence of the neuralgia has occurred. The usefulness of CISS-MRI for the diagnosis of glossopharyngeal neuralgia is discussed.

Circulating Blood Volume in Patients with Subarachnoid Haemorrhage

Summaryu2003To establish the fluid management for patients with subarachnoid haemorrhage (SAH), circulating blood volume (BV) was measured by pulse-spectrophotometry using indocyanine green (ICG) in 34 cases with SAH and 20 cases with neurosurgical disorders as control. BV measured immediately after induction of anaesthesia was lower in cases with SAH than that in controls. (62.8±12.3 vs. 73.3±11.2 ml/kg, p<0.01). In cases with SAH, the BV was significantly decreased in females (p<0.05) but not so significantly in males. In female cases with SAH, reduced BV was increased 3 days after operation (p<0.01). In conclusion BV is decreased in cases with SAH, especially in females. Active fluid therapy may be necessary when temporary vascular occlusion is required during aneurysm surgery. Since hypovolaemia may cause symptomatic vasospasm, BV measurement with pulse-spectrophotometry may provide useful information to insure normovolaemia.

Transethmoidal intranasal meningoencephalocele in an adult with recurrent meningitis.

Intranasal meningoencephalocele is a rarely encountered congenital malformation. We report a case of transethmoidal intranasal meningoencephalocele in a 52-year old man with recurrent purulent meningitis. After treatment of the acute meningitis, frontal craniotomy followed by the removal of the stalk of the meningoencephalocele and repair of the bony defect was successfully performed. He has had no further meningitis or CSF rhinorrhea post-operatively. Detailed neuroradiological examination and appropriate surgical treatment are important to prevent fatal neurological complications of intranasal meningoencephalocele.

Decrease in Intraoperative Brain Surface Temperature in Patients with Subarachnoid Haemorrhage

Summaryu2003Background. Recent experimental and clinical evidence of hypothermic protection against neuronal injury creates new interests regarding human brain temperature. However, very little information is available for the brain temperature under certain pathological conditions. In this study, intra-operative brain temperature in patients with subarachnoid haemorrhage (SAH) is particularly addressed.u2003Methods. Brain surface temperature and oxygen saturation of jugular bulb (SjO2) were monitored during early surgery undergone within 48 hours after the onset in patients with SAH (n=16). Those were also measured in patients with unruptured aneurysms during elective surgery as control (n=15).u2003Findings. The brain surface temperature was significantly lower in SAH than control (35.3±0.8 vs. 36.1±0.5°C, P<0.01). The reduction in brain surface temperature was correlated with the severity of the Hunt and Kosniks aneurysmal grade (r=0.837, P<0.01). SjO2 was significantly lower in SAH than control (51.5±7.3 vs. 68.5±7.6%, P<0.01), and was positively correlated with brain surface temperature (r=0.642, P<0.01).u2003Interpretation. These results suggest that the brain temperature and/or the temperature gradient within the brain may be altered in an early period after SAH. Since brain temperature is determined by cerebral blood flow (CBF), metabolism, temperature of both circulating blood and surrounding environment, the brain surface temperature reduction may be explained by depressed CBF and metabolism in SAH.

Advantage of Intravenous Anaesthesia for Acute Stage Surgery of Aneurysmal Subarachnoid Haemorrhage

Summaryu2003To investigate the clinical effects of intravenous anaesthesia on surgical procedure and the outcome in acute stage surgery for aneurysmal subarachnoid haemorrhage (SAH), pre-, intra-, and post-operative factors were analyzed to compare between inhalational (IA, n=38) and intravenous (IVA, n=37) anaesthesia. IVA significantly shortened the duration of surgery (p<0.05) and the duration of hospital stay (p<0.01). These results suggest that IVA may be more suitable than IA for acute stage surgery of aneurysmal SAH. These effects may be mainly caused by IVAs pharmakokinetics, by effects on intracranial homeostasis and metabolism, and neuroprotective properties.

Assessment of neuronal tract fibers using three-dimensional anisotropy contrast imaging in patients with infratentorial brain tumors

Abstract The purpose of this study was to evaluate neuronal tracts in patients with infratentorial brain tumors using three-dimensional anisotropy contrast (3DAC) imaging technique. Twenty-two patients with infratentorial tumors underwent echo-planar diffusion-weighted imaging (DWI). Gray scale DWIs in each of the three orthogonal diffusion gradients were transformed and color-coded with three primary colors to compose a 3DAC image. Morphological changes of neuronal tracts were assessed. Fine anatomical structures of neuronal tracts were visible on 3DAC images, including pyramidal tract, medial leminscus, superior and middle cerebellar peduncles. Pathological findings of these tracts were categorized as compression or displacement, alteration of fiber directionality, involvement in tumor invasion or perifocal edema, and loss of anisotropy characterized by fading of their own color. Among these, only the loss of anisotropy was correlated with presenting tract-related deficits. The 3DAC imaging is useful to evaluate infratentorial neuronal tracts and to provide useful information to determine surgical strategy in patients with infratentorial brain tumors.