Results of a long-term follow-up after neuroendoscopic biopsy procedure and third ventriculostomy in patients with intracranial germinomas.

OBJECT: The authors report the results of long-term follow-ups in 12 patients with intracranial germinomas who underwent neuroendoscopic procedures before chemotherapy and radiotherapy, and discuss the usefulness and safety of these procedures. METHODS: Between January 1996 and December 2005 at Kyushu University Hospital, 12 patients with intracranial germinomas underwent neuroendoscopic biopsy procedures involving a flexible fiberscope. Eight patients simultaneously underwent endoscopic third ventriculostomy (ETV) for existing obstructive hydrocephalus. All patients received chemotherapy and radiotherapy postoperatively, according to the regimen promulgated by the Japanese Pediatric Brain Tumor Study Group. The patients were followed for an average of 78.6 months (range 15-134 months), and a retrospective study was conducted. RESULTS: Germinomas were histologically verified in all patients. No postoperative deaths or permanent morbidity was related to the neuroendoscopic procedures. No other cerebrospinal fluid diversion, such as that achieved with a ventriculoperitoneal shunt, was needed for the management of hydrocephalus. A complete response to postoperative chemotherapy and radiotherapy was achieved in all cases. Only one patient had a recurrent lesion in the spinal cord 6 years after the initial treatment; however, this patient had undergone only the neuroendoscopic biopsy procedure without ETV. CONCLUSIONS: Neuroendoscopic procedures can permit a precise histological diagnosis of intracranial germinomas and are safe and effective in the management of hydrocephalus associated with these tumors. The risk of tumor dissemination due to the neuroendoscopic procedures appears to be minimal when the appropriate chemotherapy and radiotherapy are provided postoperatively.

Delayed effects of the microvascular decompression on hemifacial spasm: a retrospective study of 131 consecutive operated cases.

We reviewed 131 consecutive cases operated for hemifacial spasm (HFS) by the same surgeon between January 1983 and April 1999. Microvascular decompression (MVD) was performed via lateral suboccipital approach. Post-operative follow-up ranged from 1.5 to 10 years (average 34 months). The final outcome divided into three categories, excellent (total recovery) in 120 cases (91.6%), partial (> 75% recovery) in 4 cases (3.1%), and unchanged or recurrent in 7 cases (5.3%). Only 2 cases were re-operated, and final outcome of both was excellent. Based on these data, we aimed to determine a period of the final judgement of MVD effect and the causative factors of delayed effects on HFS retrospectively. There were 102 complete recovered cases without hemifacial paralysis; immediate recovery from HFS was observed in 78 cases (76.5%), after 1 month in nine cases, 1-3 months in 5 cases, 3-6 months in 3 cases, 6-10 months in 2 cases, and 10-12 months in 5 cases. Thus, most cases were completely recovered within one year of observation. On the other hand, there was no statistically significant difference between immediate and delayed relief cases in clinical histories or operative observations. Therefore, our results suggest that the final judgement of the MVD effect could be made at least one year after surgery.

Impaired intracellular signal transduction via cyclic AMP contributes to cerebral vasospasm in rats with subarachnoid hemorrhage.

No drug can completely prevent vasospasm after subarachnoid hemorrhage. Impaired intracellular signal transduction by cyclic nucleotides might be involved. We investigated effects of intravenous isoproterenol and NKH477 on cerebral blood flow in rats with or without intracisternal injection of autologous blood one week previously. In controls without hemorrhage, isoproterenol at 0.01, 0.1, 1, and 10 mg kg(-1) min(-1) increased cerebral blood flow by 1.2%+/-9.5%, 19.7%+/-12.8%, 46.8%+/-23.5%, and 63.8%+/-32.9% respectively; 10mg kg(-1) min(-1) of isoproterenol increased systemic blood pressure by 66.6%+/-58.1%, while other doses decreased blood pressure. In the subarachnoid hemorrhage group, isoproterenol increased cerebral blood flow by -20.0%+/-6.5%, -7.6%+/-8.7%, 8.2%+/-8.8%, and 35.9%+/-83.1% respectively; 10 mg kg(-1) min(-1) of isoproterenol increased systemic blood pressure by 68.8%+/-79.5%, while other doses decreased blood pressure. In controls, NKH477 at 3, 10, and 30 mg kg(-1) increased cerebral blood flow by 2.3%+/-3.6%, 14.4%+/-7.0%, and 50.7%+/-14.6%, respectively; in the subarachnoid hemorrhage group, NKH477 changed cerebral blood flow by -1.3%+/-2.4%, 4.6%+/-2.8%, and -12.6%+/-10.8% (not significant difference from controls). NKH477 at 30 mg kg(-1) min(-1) decreased systemic blood pressure in both groups, but the effect in the hemorrhage group was greater. Either isoproterenol or NKH477 at appropriate doses can increase cerebral blood flow in vasospasm following subarachnoid hemorrhage without decreasing blood pressure.

Type V phosphodiesterase expression in cerebral arteries with vasospasm after subarachnoid hemorrhage in a canine model.

Cyclic GMP (cGMP) mediates smooth muscle relaxation in the central nervous system. In subarachnoid hemorrhage (SAH), decreases in intrinsic nitric oxide (NO) cause cerebral vasospasms due to the regulation of cGMP formation by NO-mediated pathways. As phosphodiesterase type V (PDE V) selectively hydrolyzes cGMP, we hypothesized that PDE V may function in the initiation of vasospasm. This study sought to identify the altered PDE V expression and activity in the vasospastic artery in a canine SAH model. We also used this system to examine possible therapeutic strategies to prevent vasospasm. Using a canine model of SAH, we induced cerebral vasospasm in the basilar artery (BA). Following angiographic confirmation of vasospasm on day 7, PDE V expression was immunohistochemically identified in smooth muscle cells of the vasospastic BA but not in cells of a control artery. The isolation of PDE enzymes using a sepharose column confirmed increased PDE V activity in the vasospastic artery only through both inhibition studies, using the highly selective PDE V inhibitor, sildenafil citrate, and Western blotting. Preliminary in vivo experiment using an oral PDE V inhibitor at 0.83 mg kg(-1) demonstrated partial relaxation of the spastic BA. PDE V activity was increased from control levels within the BA seven days after SAH. PDE V expression was most prominent in smooth muscle cells following SAH. These results suggest that clinical administration of a PDE V inhibitor may be a useful therapeutic tool in the prevention of vasospasm following SAH.

Classification of medullary venous malformations in the temporal lobe: according to location and drainage pathway.

Medullary venous malformation (MVM) is rare in the temporal lobe, and the radiologic characteristics of temporal MVM have not yet been clarified. In 12 previously reported cases with satisfactory angiographic or magnetic resonance information as well as two newly reported here, we analyzed the specific location and hemodynamics of temporal lobe MVMs, particularly with respect to venous drainage. Temporal lobe MVM typically were seen in the superior lateral portion of the temporal lobe near either the atrium or the inferior horn of the lateral ventricle. Venous drainage was classified into two main patterns: deep (three cases) and superficial (11 cases). Superficial drainage could be divided into two subtypes: lateral and anterior. Dilated deep medullary veins converged toward either the lateral wall of the atrium or the inferior horn of the lateral ventricle. In the deep-drainage type, medullary veins drained into subependymal veins such as the inferior ventricular vein and the lateral atrial vein, and then emptied into the basal vein of Rosenthal. The anastomotic lateral mesencephalic vein was involved in one case as a variant of the basal vein. When the subependymal veins and/or the basal vein of Rosenthal or transverse sinus were hypoplasic, the medullary veins drained into either the Sylvian veins (anterior superficial type) or the vein of Labbé (lateral superficial type) through a characteristic large transcerebral vein. Drainage of temporal lobe MVM can be classified as deep, lateral superficial, or anterior superficial.

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.

Occurrence of subdural hematoma and resolution of gait disturbance in a patient treated with shunting for normal pressure hydrocephalus.

A 66-year-old man with gait disturbance was diagnosed with normal pressure hydrocephalus (NPH) and treated with ventriculoperitoneal shunting using a programmable valve. The valve ultimately set at a pressure of 40 mm H(2)O after higher settings no longer relieved symptoms. However, this pressure setting was excessively low and was associated with occurrence of bilateral subdural hematomas. Paradoxically, this event was associated with stable improvement of gait. Our patient's gait disturbance was unassociated with muscle weakness, spasticity, cerebellar ataxia, or Romberg's sign, and, therefore, was consistent with a frontal gait disorder. Cerebral cortical blood flow as measured after shunting by single photon emission computed tomography (SPECT) was slightly increased from the value before shunting, possibly because of intracranial hypotension related to the valve setting. Lasting improvement of gait in our case may be a result of increased blood flow in the supplementary motor area (SMA).

Unilateral striatal damage following status epilepticus of ipsilateral frontal lobe origin.

A 35-year-old man with an old contusional haematoma in the right frontal lobe developed status epilepticus (SE) of right frontal origin. On magnetic resonance (MR) images 10 days after SE, the right striatum showed signal enhancement with Gd-DTPA administration. Subsequent MR imaging 1 month later indicated prolonged T1 and T2 relaxation times in the right striatum. Prolonged seizure activity in the frontal lobe may have induced excitatory neurotoxicity in the ipsilateral striatum, with occurrence of delayed neuronal damage as a result.

Intradural, extramedullary spinal Ewing's sarcoma in childhood.

We describe an 11 year old girl with progressive paraparesis from a spinal tumour. Magnetic resonance imaging showed an intradural, extramedullary mass extending from the C7 level to T1. Neither osteolytic nor osteosclerotic changes were seen in the vertebral bodies. Extraskeletal Ewing's sarcoma was diagnosed histopathologically.

An infant with an intradural lipoma of the cervical spine extending into the posterior fossa.

BACKGROUND: Intradural lipomas of the cervical spine are very rare. These tumours show no association with spinal dysraphism. We describe an infant with cervical spinal cord lipoma. Surgical decompression of the cord resolved all neurologic deficits. CASE DESCRIPTION: An 8 month old female infant presented with retarded development of motor function in the limbs, in addition to dysphagia. Computed tomography identified a tumour of fat density that extended from the medulla to C7. Magnetic resonance imaging showed hyperintensity on both T1- and T2-weighted images. A fat-suppression sequence demonstrated an area of signal enhancement in the dorsal portion of the tumour following administration of gadolinium. The adjacent spinal cord was normal. Partial removal of the tumour was performed together with decompressive laminoplasty. The enhancing region proved to be fibrous tissue. Motor development resumed in the week following operation. CONCLUSION: Retarded motor development was the main manifestation of this infant's rare spinal tumour. Neuroimaging was of considerable diagnostic value; in particular, fat-suppression magnetic resonance imaging demonstrated details of the tumour and surrounding structures. Decompressive laminoplasty and laminectomy with partial removal of the tumour was effective in reversing clinical deficits.

Magnetic resonance imaging in cases with encephalopathy secondary to immunosuppressive agents.

The neurotoxic effects of immunosuppressive agents used after transplantation are well known. In most cases a decrease in drug dosage results in resolution of the neurotoxicity. At early stages in the post-transplantation clinical course, neurotoxicity and other complications such as infectious disease, encephalopathy and seizures are sometimes difficult to diagnose with neuroimaging. Recently, diffusion weighted imaging (DWI) has been used in patients with ischemic disease, mitochondrial myopathy, encephalopathy and demyelinating disease. We examined the magnetic resonance images (MRI), including DWI and fluid attenuated inversion recovery image (FLAIR), in three cases of post-transplantation neurological complication: two cases of neurotoxicity and a case of acute disseminated encephalomyelitis (ADEM). Hyper-intense lesions representing neurotoxicity were seen on FLAIR but not on DWI in two cases with neurotoxicity induced by an immunosuppressive agent. In ADEM, hyper-intense lesions were seen on both FLAIR and DWI. Neurotoxicity due to the immunosuppressive agent showed a favorable outcome, although the hyper-intense lesions temporally presented on FLAIR. In the state after transplantation, hyper-intense lesions on FLAIR and DWI represented in the brain from the initial stage, we might be care of other severe complications but for neurotoxicity.

Decreased thalamic metabolism without thalamic magnetic resonance imaging abnormalities following shearing injury to the substantia nigra.

A 36-year-old man had fallen about 8 metres. Radiographs showed a mandibular fracture, indicating rotatory force applied to the head. Fluid-attenuated inversion recovery (FLAIR) imaging showed hyperintensity in both medial temporal lobes, left medial midbrain, right midbrain including cerebral peduncle, left pulvinar, left external capsule, fornix, splenium of corpus callosum, and deep white matter of both frontal lobes. Quantitative [(18)F]fluorodeoxyglucose (FDG)-positron emission tomography (PET) indicated markedly suppressed glucose metabolism in the left thalamus but not markedly in the striatum. At that time the neurologic examination demonstrated complete left hemiparesis, severe rigidity of the right upper extremity, and inability to move the right hand and fingers. Levodopa at 300-600 mg/day improved movement of the fingers, decreased the rigidity in the extremity, and lessened the metabolic abnormality. Diminished metabolism in the left thalamus may have contributed to symptoms. The case illustrates the usefulness of PET in disclosing symptom causing abnormalities not detected by magnetic resonance imaging.

Gait disturbance in patients with low pressure hydrocephalus.

Using criteria of the classification recently described by Nutt et al., we examined gait disorder in five patients with normal pressure hydrocephalus (NPH). Their cerebrospinal fluid (CSF) pressures were in the normal range, and trials of CSF removal produced temporary improvement of symptoms. Surgical procedures to relieve hydrocephalus improved gait disorders in all patients. No patient showed spasticity, sensory ataxia, cerebellar ataxia, extrapyramidal signs, or limb apraxia. All walked slowly with a wide base and a short stride. The arm swing normally associated with walking was preserved. In standing, patients were unsteady and fell easily when pushed. Four patients showed hesitation in initiating walking and in turning. These clinical features fit Nutt's criteria for frontal gait disorder and frontal disequilibrium. Unlike findings in Parkinson's disease, where similar gait disorders may occur, other extrapyramidal signs, Myerson's sign, and upper limb dysfunction were absent in NPH, and arm swing while walking was preserved. We suspect that ventricular dilatation disturbs neuronal connections between the supplementary motor area and the globus pallidus in NPH patients.

Ruptured saccular aneurysm of a dolichoectatic internal carotid artery in a patient with agenesis of the contralateral internal carotid artery--case report.

A 42-year-old woman presented with very rare cases of ruptured saccular aneurysm of a dolichoectatic internal carotid artery (ICA) associated with agenesis of the contralateral ICA manifesting as sudden onset of severe headache and nausea without neurological deficits. Angiography and three-dimensional computed tomography demonstrated intraventricular hemorrhage with slight subarachnoid hemorrhage and dolichoectasia of the right ICA with agenesis of the contralateral ICA, as well as a saccular aneurysm of the ectatic right ICA. The aneurysm neck was clipped successfully. The patient remained ambulatory with no neurological deficits at discharge 15 days after the surgery. The saccular aneurysm in our case was formed in the dolichoectatic ICA, presumably due to both abnormal hemodynamics and abnormal arterial wall.

[A case of severe parkinsonism induced by failure of ventriculo-peritoneal shunt for aqueductal stenosis].

A 26-year-old man, who had received a ventriculo-peritoneal shunt for obstructive hydrocephalus after possible encephalitis, complained of disturbance of upward gaze and difficulty in movement seven months after the shunt implantation. One month later, neurological examination revealed upward gaze paresis and rigidity of all four limbs, but the neuroimaging studies revealed no ventricular dilatation. His symptoms deteriorated, and tremor of the extremities appeared. He was admitted to our hospital 10 months after the shunt implantation. He developed akinetic mutism soon after admission. Cerebrospinal fluid protein was elevated (62 mg/dl). At that time, the shunt reservoir was found to be insufficiently filled, and neuroimaging showed dilatation of the lateral and third ventricles with no dilatation of the fourth ventricle. A neuroendoscopic third ventriculostomy with removal of the previous shunt system gradually resolved the parkinsonism within two months, and the patient became capable of walking. The dilatation of the ventricles improved on neuroimaging. The present report suggests that shunt malfunction should be suspected when parkinsonism occurs in patients who have undergone a shunt placement, even though hydrocephalus on neuroimaging is not observed.

[A case of traumatic sinus pericranii].

Sinus pericranii is a rare vascular anomaly involving an abnormal communication between the extracranial and intracranial circulations. A 33-year-old woman presented with a soft tissue mass at the left frontal region. It was associated with head trauma when she was 12-year-old. The mass had gradually grown and become painful for 20 years. She underwent surgical resection of the mass successfully. This report discusses traumatic sinus pericranii.

[A case of pineoblastoma primary presenting a pineal hemorrhage causing obstructive hydrocephalus].

A 9-year-old female suddenly developed headache and nausea. Computed tomography (CT) revealed pineal mass lesion and obstructive hydrocephalus. One week after the onset, hydrocephalus spontaneously resolved. Magnetic resonance imaging (MRI) revealed that the mass was a subacute hematoma and that hydrocephalus had improved. Sequential MRI 4 months later revealed an enhanced lesion in the pineal region. Total removal of the tumor by the occipital transtentorial approach established the histopathological diagnosis of pineoblastoma.

[A lesion diagnosed by MRI in a case of transient global amnesia].

Transient global amnesia(TGA) had been recognized as a disease without abnormal findings on neuroimaging before magnetic resonance(MRI) imaging was practicable. Recently, abnormal findings on MRI reported in cases of TGA. We here reported a case of TGA showing a transient abnormal intensity in left hippocampus on MRI diffusion-weighted image. A 52-year-old man suddenly became to unable to keep his recent memory without histories of trauma or epilepsy. He showed no abnormal neurologic findings excepting for the recent memory. MRI performed within an hour after onset demonstrated no abnormality on T1- and T2-weighted images. Diffusion-weighted image (b = 1,000) showed hyperintensity in the left medial temporal lobe, and the apparent diffusion coefficient(ADC) in this region was lower(72.8 cm2/s) than that in the contralateral region(94.4 cm2/s). TGA was completely resolved 17 hours after onset.

[Severe hyponatremia in a case of severe spinal injury: sequential examination of factors affecting water-electrolyte balance].

Although hyponatremia has been known to occur in patients with severe spinal cord injury with highly incidence, its mechanism has not been understood well. We examined a 64-year-old patient with severe hyponatremia after spinal cord injury by sequential measuring of the factors affecting water-electrolyte balance, such as antidiuretic hormone, renin, angiotensin II, atrial natriuretic peptide, and brain natriuretic peptide. The patient showed severe hypotension due to dysfunction of the sympathetic nerve. The hyponatremia gradually resolved with the improvement of sympathetic nerve function. According to those results, the sympathetic nerve dysfunction was thought to correlate with the hyponatremia, and it was suggested that the unknown sympathetic regulation of water-electrolyte balance existed.

Diverticular enlargement of the foramina of Luschka and congenital hydrocephalus.

CASE REPORT: We report on a 9-month-old boy with congenital hydrocephalus involving cystic lesions in the bilateral cerebellopontine angle cisterns. Sequential CT cisternography demonstrated congenital obstruction of the fourth ventricular outlet and diverticular enlargement of the foramina of Luschka. DISCUSSION: The possibility of neuroendoscopic third ventriculostomy as a treatment for these pathologies is discussed.