[Surgical treatment for symptomatic arachnoid cysts].

During the period from 1983 to 1999, 12 patients with symptomatic arachnoid cyst were treated. The mean patient age was 20.6 years. The most common location was the middle fossa (10 cases). Initial CT scan revealed associated subdural hygroma in 7 patients and hydrocephalus in one. Clinical symptoms were related to increased intracranial pressure, cranio-megaly and seizure. One infant with a huge arachnoid cyst was treated, using a cystoperitoneal (CP) shunt. Four patients underwent membraectomy. Combination CP shunt and membraectomy was performed in 5 patients. The remaining 2 arachnoid cysts were complicated with subdural hygroma and, initially, they were observed conservatively, but hygroma gradually changed to hematoma. One was treated by irrigation and the other hematoma was spontaneously absorbed. Significant complications included extensive subdural effusion in one patient, contralateral chronic subdural hematoma in two, intracranial hypotension in two, and shunt dependency in one. There were no recurrences during the follow-up period (mean 3.6 years).

Migration of a lumboperitoneal shunt catheter into the spinal canal--case report.

A 50-year-old female suffered upward migration of a lumboperitoneal (LP) shunt catheter into the spinal canal, manifesting as disturbance of short-term memory. Revision of the shunt confirmed that the tube had migrated into the spinal canal. The tube was pulled back into the peritoneal cavity and attached firmly to the fascia with a new anchoring device. LP shunts have the advantages of technical simplicity and extracranial procedure, but firm fixation is recommended since movements of the spine may cause proximal tube migration.

[A case of intravascular malignant lymphomatosis presenting as cerebral infarction].

A case of intravascular malignant lymphomatosis (IML) presenting as progressive cerebral infarction is reported. A 62-year-old previously healthy male developed progressive dementia. MRI of the brain at the nearest hospital revealed multiple infarcts with unknown etiology. His level of consciousness deteriorated rapidly, and then he was transferred to our hospital for further evaluation. High grade fever, raised serum C reactive protein (CRP), and raised lymphoma markers (serum LDH and soluble IL-2 receptor (sIL-2R)) were observed. Repeated brain MRI disclosed progression of multifocal cerebral infarctions. We considered IML most likely, and we performed muscle biopsy. However muscle biopsy didn't demonstrate any proliferation of neoplastic cells of lymphoid origin within small vessels. Thereafter IML was diagnosed by brain biopsy. The patient underwent chemotherapy, but died of pneumonia due to severe myelosuppression. IML is a rare disease but most commonly shows neurological symptomatology as its clinical manifestation. Dementia is the most common neurological symptom, and progressive multiple infarction is the most common of the MRI findings. Rapidly progressive dementia associated with multiple infarction, when elevated CRP, LDH and sIL-2R are observed in the laboratory data, is suggestive of IML.

[A case of psoriatic arthropathy complicated with spinal fracture and epidural hematoma].

A 78-year-old man with psoriatic arthropathy complicated with traumatic spinal fracture and epidural hematoma is reported. He had fallen down the stairs. On admission one hour after injury, he developed an incomplete C6 quadriparesis. CT revealed a C6-7 fracture and dislocation on sagittal reconstruction. MR imaging disclosed the compression of the spinal cord between the posterior margin of the vertebral body and an epidural hematoma. The patient had had the skin lesion, psoriasis vulgaris, for about 20 years and been previously treated for uveitis. Serological tests for rheumatoid factor and HLA B-27 were negative. Emergent laminectomy and evacuation of the epidural hematoma were carried out because of progressive neurological deterioration. Osteoporotic laminar bone and ossified yellow ligament were observed to have been fractured. Conservative therapy was selected for spinal instability. Although a respiratory complication occurred postoperatively, he was transferred to the rehabilitation facility in an improved neurological condition.

Ectopic expression of the bHLH gene Math1 disturbs neural development.

The basic helix-loop-helix gene Math1, a positive regulator of neuronal differentiation, is specifically expressed in the dorsal part of the developing nervous system. To determine the effects of ectopic expression of Math1, we generated two transgenic mouse lines; One carried the Cre recombinase gene under the control of the nestin promoter and enhancer, which direct expression in neural precursor cells, and the other carried the Math1 gene, the expression of which was regulated by the cytomegalovirus (CMV) promoter but interrupted by the stop cassette flanked by loxP sites. In F1 embryos that carried the two transgenes, the stop cassette was removed by Cre recombinase in the developing nervous system, and Math1 expression was ectopically directed from the CMV promoter. We found that these embryos exhibited abnormal morphology of the brain and extensive cell death in the nervous system. These results suggest that ectopic expression of Math1 is toxic to neurons and leads to apoptosis.

Endovascular treatment of aneurysms on the feeding arteries of intracranial arteriovenous malformations.

The association between intracranial aneurysms and arteriovenous malformations (AVMs) is well documented. Recent advances in the understanding of the haemodynamics of this association encourage an aggressive approach to these aneurysms. However, the pathophysiology of these aneurysms is not fully understood and a strategy for their management has not been established. We describe seven patients, with eight aneurysms, on the feeding arteries of AVMs. The aneurysms could be divided into those located 1. proximally on the superficial feeding artery (type I; 4 aneurysms); 2. distally on the superficial feeding artery (type II; 3 aneurysms); and 3. on the deep feeding artery (type III; 1 aneurysm). All aneurysms were treated by the endovascular procedure prior to, or simultaneously with, treatment of the AVM, using detachable coils or liquid embolic material. All aneurysms were obliterated successfully, with no adverse events. Each patient further received treatment of the AVM. None of the patients suffered intracranial haemorrhage after treatment for the aneurysms. Based on our experiences, we discuss the indications for this approach for each type of aneurysm. We believe endovascular treatment could be an important alternative for treatment of aneurysms associated with AVMs, thus reducing the risk of haemorrhage.

Initial experiences of carotid stenting with palmaz stent.

Results of cervical carotid stenting are reported. Twenty-nine lesions in 25 cases were treated by percutaneous transluminal balloon angioplasty combined with stent placement. All the lesions were successfully dilated. There was one embolic complication during the operation that caused deterioration of preoperative symptoms. Stent deformation causing more than 30% luminal narrowing occurred in one case. Instent restenosis with more than 50% luminal narrowing was seen in bilateral lesions in one case. These were satisfactory results as an initial experience, but further improvement in this technique is considered essential especially to avoid embolic complications.

Modification of immediately electrically detachable coil.

An immediately electrically detachable coil (IEDC) that we previously developed was modified to enhance the reliability in its detachment system. IEDC is detached by applying a monopolar high-frequency electrical current that heat and disrupt a junction between a platinum coil and a delivery wire. The original IEDC immediately detaches only when the junction is just outside the catheter tip and precise positioning of the junction is required. In the modified IEDC, its delivery wire was insulated with poly tetra fluoroethylene (PTFE) to concentrate electrical current to the junction. The modified IEDC was tested in vitro and in animal experiments. Modified IEDC always detached instantaneously even when the junction was far beyond the catheter tip. Insulated delivery wire enabled the electrical current to be concentrated at the PVA junction and produce appropriate heat to disrupt the junction.

Structure, chromosomal locus, and promoter of mouse Hes2 gene, a homologue of Drosophila hairy and Enhancer of split.

Hes2 encodes a mammalian basic helix-loop-helix transcriptional repressor homologous to the products of Drosophila hairy and Enhancer of split. Here, we isolated and characterized the mouse Hes2 gene. This gene consists of four exons, and all the introns are located within the protein-coding region at positions homologous to those of other Hes genes. On the inter-specific backcross analyses, mouse Hes2 is mapped to the distal region of Chromosome 4 near the Hes3 and Hes5 loci, which are different from the Hes1 locus on Chromosome 16. Upstream of the transcription initiation site, there are GC-rich regions, but a typical TATA box is not present. Transient transfection analyses demonstrated that, while Hes1 and Hes5 promoter activities are significantly upregulated by the active form of Notch, a key regulator of cellular differentiation, Hes2 and Hes3 promoter activities are not. These results suggest that Hes genes are functionally classified into two groups: those that are regulated by Notch and those that are not.

Endovascular treatment of a partially thrombosed giant basilar tip aneurysm using interlocking detachable coils--case report.

A 65-year-old female presented with visual acuity loss. Magnetic resonance imaging confirmed the presence of a partially thrombosed giant aneurysm on the basilar tip. Cerebral angiography showed the opacified lumen of the aneurysm was 25 x 15 mm with a broad-based neck. Using a transfemoral approach, a microcatheter was guided through the vertebral artery and placed directly into the aneurysm under local anesthesia. Interlocking detachable coils were deposited into the patent portion of the aneurysm, resulting in 95% obliteration of the aneurysm and preservation of the parent artery. No complication was observed during or after surgery. Follow-up angiography 2 months later demonstrated the aneurysm was 95% occluded. No coil compaction was observed. Endovascular coil embolization therapy provides a therapeutic option for management of basilar tip aneurysms.

[A case of cavernous dural arteriovenous fistula resulting in intracerebral extravasation during transvenous embolization].

Cortical venous drainage has been described as one of the major risk factors for dural arteriovenous fistula, which may induce venous hypertension leading to venous ischemia or intracerebral hemorrhage. However, it is rather rare to observe cortical venous drainage manifesting in this way in the cavernous sinus region. We report a case of a 55-year-old gentleman with a right cavernous dural arteriovenous fistula, presenting with conjunctival chemosis, exophthalmus and ocular hypertension on the affected side. Magnetic resonance imaging showed a small intracerebral hemorrhage in the right frontal lobe. Cerebral angiography revealed a dural arteriovenous fistula in the right cavernous sinus draining into the right olfactory vein via the uncal vein, as well as into the superior and inferior ophthalmic veins. This unusual cortical venous reflux was thought to be consistent with the intracerebral hemorrhage found on the magnetic resonance imaging. The patient underwent transvenous embolization for the dural arteriovenous fistula using an inferior petrosal catheterization into the uncal vein was difficult, and the cortical venous reflux through the vein seemed to be slight. However, extravasation of the contrast material occurred in the right frontal lobe after obliteration of the ophthalmic veins during the procedure. The cause of the extravasation was suspected to be the same olfactory vein that had been involved in the previous intracerebral hemorrhage. The obliteration of the dural fistula was continued rapidly, and the fistula disappeared after the embolization. Neurologically, the patient had no noticeable troubles, except for a mild headache. The pretreatment symptoms were alleviated within several days, and the patient was discharged in a week. We emphasize the following points from this rare case in order to facilitate a safer procedure during transvenous embolization for cavernous dural arteriovenous fistula. It is important to obliterate the cortical venous drainage as early as possible, even if the reflux is small or the catheterization is difficult. Repeated, careful sinography is useful for the evaluation of the drainage pattern at certain stages during the transvenous embolization procedure.

Intra-aneurysmal Occlusion of Cerebral Aneurysms Using Detachable Coils. Correlation of Aneurysm Neck Size and Treatment Results.

SUMMARY: The aneurysmal neck size seems to be an important factor in the endovascular treatment outcome(4,5). The purpose of the present study was to measure aneurysm neck size on angiographic films, and compare the measured value with the extent of intra-aneurysmal occlusion performed with detachable coils. The subjects were 22 patients with intracranial aneurysms treated using detachable coils. The cases were divided into two groups according to the aneurysmal neck size, 4 mm being the discriminating value for small neck. The neck of the aneurysm was successfully occluded in 19 of 22 patients. Ten aneurysms had a small neck and 9 aneurysms had a wide neck. Complete aneurysm occlusion was observed in 70% of small neck aneurysms and 25% of wide neck aneurysms. The results support that the size of the aneurysm neck correlates well with the effectiveness of endovascular treatment.

Genetic mapping of four mouse bHLH genes related to Drosophila proneural gene atonal.

It has been shown that mammalian neurogenesis is partly controlled by multiple basic helix-loop-helix (bHLH) genes, as in Drosophila. Recently, mouse homologs of Drosophila atonal, a proneural gene encoding a bHLH protein required for chordotonal organ and photoreceptor development, have been characterized to obtain further insights into the molecular nature of mammalian neurogenesis. Here, to assess their potential involvement in genetic neural disorders, we have determined genetic map positions for four mouse atonal-related genes, Atoh1, Atoh2, Atoh3, and Ndrf, which encode MATH-1, MATH-2, MATH-3, and NDRF, respectively. Interspecific backcross analysis indicated that Atoh1 and Atoh2 were located in separate positions of Chr 6 and that Atoh3 and Ndrf were mapped to Chr 10 and Chr 11, respectively. Thus, these structurally related genes are located separately on multiple chromosomes.