Ken Kamiya

Deterioration of ocular motor dysfunction after transvenous embolization of dural arteriovenous fistula involving the cavernous sinus.

Summary We treated 9 patients with the dural arteriovenous fistula involving the cavernous sinus by transvenous embolization. Two patients experienced deterioration of oculo-motor dysfunction after transvenous embolization. We can speculate about two different kind of causes by which patients symptoms deteriorated according to the result of intrasinus pressure recorded during the embolization [1]: high intrasinus pressure caused by the obliteration of the drainage pathway resulted in cranial nerve palsy in one case [2]; implanted coils directly compressed the cranial nerve in another case. Fortunately our cases recovered, but some kind of preventative measures may be needed in similar cases.

Neurenteric cyst at the craniovertebral junction: report of two cases

BACKGROUND Neurenteric cysts are rare endothelium-lined structures. Two patients with symptomatic neurenteric cysts at the craniovertebral junction are presented. CASE PRESENTATION Intermittent progression of neurologic symptoms delayed diagnosis for both patients. In one case, marked enlargement of the cyst was detected on serial imaging studies, and pathological examination of the excised lesion indicated rupture of the cyst. These cysts were totally resected by transoral or suboccipital approaches, as they were not firmly adherent to surrounding neural structures. The diagnosis of neurenteric cyst was confirmed by immunohistochemical analysis of the cyst wall. CONCLUSION In view of the clinical course of these patients, we recommend early surgical resection of neurenteric cysts located at the craniovertebral junction.

Changes in intracranial pressure (ICP) pulse wave following hydrocephalus

SummaryThe pulse pressure (PP) of the intracranial pressure pulse wave (ICPPW) was measured in experimental and clinical hydrocephalus: namely, obstructive and kaolin-induced hydrocephalus as an experimental study, and noncommunicating and communicating hydrocephalus as a clinical study.At approximately the same ICP level, the PP was much higher in the obstructive hydrocephalus group and slightly higher in the kaolin-induced hydrocephalus group than in the controls. Also the PP level in noncommunicating hydrocephalus patients [3.19mm Hg (SD: 1.04)] was significantly (P<0.05) higher than that in the communicating hydrocephalus patients [1.88 mm Hg (SD: 0.60)].The results of our research suggest that the stronger the disturbance of the communication of the CSF between cranial cavity and spinal cavity the higher the PP of ICPPW. This results from the distensibility of the spinal dural sac and exerts a great influence on the elasticity and the PP of the cranial system. It is reasonable, therefore, to suggest that a marked increase in the ratio of the PP to the ICP in the normal or slightly high ICP hydrocephalus may indicate disturbance of the CSF flow, especially loss of CSF communication between the cranial and spinal compartments.

Subarachnoid hemorrhage induces c-fos, c-jun and hsp70 mRNA expression in rat brain

TO detect stress responses of the brain to subarachnoid hemorrhage (SAH), we investigated the expression of immediate early genes (IEGs) and hsp70 mRNA by in situ hybridization. Experimental SAH was produced in 49 rats by endovascular penetration. We also monitored the intracranial pressure (ICP) changes. The genes c-fos and c-jun were induced in the cerebral cortex, hippocampus and dentate gyrus in the penetrated side. mRNA coding for hsp70 was induced in the cerebral cortex, hippocampus, thalamus, hypothalamus and caudoputamen in the penetrated side and extended to the contralateral hemisphere. IEGs in the cerebral cortex were completely blocked by MK-801 pretreatment, but hsp70 mRNA was not. This suggests that the expression of IEGs correlates with spreading depression. The IEGs and hsp70 expression may reflect the severity of SAH impact and relate to the mechanisms of symptomatic vasospasm.

Immature teratoma producing alpha-fetoprotein without components of yolk sac tumor in the pineal region

Abstract A case of pineal region tumor in a 9-year-old boy with a high serum alpha fetoprotein (AFP) level is reported. The serum levels of beta-human chorionic gonadotropin (HCG) and placental alkaline phosphatase (PLAP) were not elevated. The tumor was composed of radiologically different components and was removed surgically. Postoperative radiation therapy was performed and the serum level of AFP gradually declined to the normal range. The pathological diagnosis was immature teratoma, and no elements of yolk sac tumor or embryonal carcinoma were found. In the immunohistochemical study, AFP was detected in the cytoplasm of gastrointestinal-type epithelium and primitive neuroepithelial element. This is considered a rare case of intracranial immature teratoma in which AFP was detected immunohistochemically in the columnar epithelium and immature neural tissue.

Peripheral anterior inferior cerebellar artery aneurysms

Two cases of peripheral anterior inferior cerebellar artery (AICA) aneurysms are reported. The first case was a 60-year-old man who showed frequent attacks of subarachnoid hemorrhage (SAH) and hearing disturbance. His aneurysm was obliterated by trapping the AICA and his neurologic status was unchanged compared with preoperatively. The second case had SAH without cranial nerve involvement; this aneurysm was obliterated by neck clipping. He was discharged without neurologic deficit. Peripheral AICA aneurysm has already been reported in 48 cases including arteriovenous malformation-associated cases. This aneurysm may show cranial nerve involvement (seventh and eighth) without SAH as in the case of internal carotid-posterior communicating artery aneurysms. We review the clinical signs of these cases and discuss them from the point of view of anatomic variations of the AICA and internal auditory artery.

CO2 reactivity and autoregulation in fetal brain

Intraventricular hemorrhage (IVH) in preterm infants is well known to be associated with the high morbidity and mortality of this group. Previous studies have suggested altered cerebral blood flow (CBF) as an important pathologic factor. We measured the CBF in nearterm rabbit fetuses using the hydrogen clearance technique. The local CBF of the rabbit fetuses was significantly low compared with that of the maternal rabbits. The response of CBF to changes in PaCO2 was observed in rabbit fetuses. The CO2 reactivity index of the fetal rabbit was lower than that of the maternal rabbit. This low CO2 reactivity might reflect the immaturity of the fetal brain and its low CBF. We were unable to monitor the fetal blood pressure, but the fetal CBF remained stable when the maternal blood pressure was altered. It is well known that IVH in preterm infants originates from the subependymal germinal matrix and that this has many fragile vessels. Our observation suggests that even a small increase of CBF during hypercapnia might have a large effect towards producing hemorrhage.

Primidone-induced hyperammonemic encephalopathy in a patient with cerebral astrocytoma

A case of a patient with astrocytoma who showed somnolence and asterixis one month after tumour resection is presented. Although primidone had been prescribed preoperatively for five years and the same dose was maintained after the operation, the serum concentration of the primidone metabolite phenobarbital was elevated and she demonstrated hyperammonemic encephalopathy, which disappeared on withdrawal of the drug. A description of this seldom reported phenomenon during primidone therapy is given, with reference to valproate cases.

Comparison of thallium-201 uptake and retention indices for evaluation of brain lesions with SPECT

Thallium-201 chloride single photon emission computed tomography ((201)TlCl SPECT) has been applied extensively for studies of human tumors. To assess which indices for (201)TlCl SPECT are most useful for diagnosing brain lesions, a total of 82 patients (98 images) with intracranial abnormalities were investigated. Seventy-six cases with abnormal (201)Tl uptake were evaluated in terms of six different (201)Tl uptake and retention indices: (1) average early (201)Tl uptake = Av.Le/Av.Be; (2) maximum early (201)Tl uptake = Mx.Le/Av.Be; (3)(201) Tl retention A = Av.Ld/Av.Le; (4) (201)Tl retention B = Mx.Ld/Mx.Le; (5) (201)Tl retention C = (Av.Ld/Av.Bd)/(Av.Le/Av.Be); (6) (201)Tl retention D = (Mx.Ld/Av.Bd)/(Mx.Le/Av.Be), where Av.Le and Mx.Le are average and maximum early counts for lesions, Av.Be and Av.Bd are average early and delayed counts for contralateral normal brains, and Av.Ld and Mx.Ld are average and maximum delayed counts for lesions. Comparison of patients with benign and malignant lesions did not demonstrate significant differences with any of the indices. However, low (I-II) and high (III-IV) grade astrocytomas varied in their average and maximum early (201)Tl uptake indices (both P = 0.0026). For patients with and without meningiomas, P values for indices of maximum early(201) Tl uptake and (201)Tl retention A and B were 0.0338, 0.0005, 0.0002, respectively. While comparison of patients with metastatic brain tumors and gliomas again showed no significant differences between the groups, the presence or absence of calcification was associated with significant variation in all the indices. With (201)TlCl-SPECT imaging, the average and maximum early (201)Tl uptake indices are appropriate for the assessment of tumor viability or malignancy, while (201)Tl retention indices (A,B) are useful for tumor differentiation, especially with meningiomas. Choice of suitable indices should enhance the utility of (201)TlCl-SPECT imaging in pre- and postoperative evaluation of intracranial lesions.

West Syndrome Associated with Porencephaly

A 3-year-old boy with West syndrome who was shown to have a cystic lesion on magnetic resonance imagings underwent surgical treatment. He had been initially managed with several antiepileptic drugs, but abnormalities on electroencephalography (EEG) persisted. Histological examination of the cystic wall obtained during surgery suggested porencephaly. Two years and 2 months later the child remained seizure-free and his EEG remarkably improved.