Takaho Murata

Clinical Analysis of Arteriovenous Malformations in Children

28 cases of arteriovenous malformations (AVMs) in children were analyzed and compared with 18 adolescent and 106 adult cases. The findings were: (1) intracerebral hematoma due to rupture of AVMs and focal neurologic deficits were more frequent in children, (2) Operative mortality was higher in children than in adults in cases where total removal was not feasible. (3) Follow-up results suggested that the prognosis in children was less favorable than in adults. (4) When dealing with spontaneous intracerebral hematoma in children care should be taken to search for underlying cryptic AVMs.

Results of Treatment for Craniopharyngioma

A review of the results of treatment for 155 cases of craniopharyngioma during the past 47 years by the palliative operation was made. Steroid and operative microscope reduced operative mortality and gave more chance of total extirpation, but survival rate was almost unchanged. It is noteworthy that 3 cases who underwent palliative operation more than 30 years ago are still alive and leading useful lives. The quality of survival was somewhat less favorable in pediatric than adult cases. Morbidity frequently encountered in pediatric cases was growth retardaton. Craniopharyngioma is a benign tumor pathohistologically, but it should be considered as malignant because of the region it occurs in. Therefore, no forceful attempt to total extirpation should be made and the operations should, as a rule, be palliative.

The significance of periventricular lucency on computed tomography: Experimental study with canine hydrocephalus

SummaryIn order to investigate the pathogenesis of periventricular lucency (PVL) in hydrocephalus, CT scans were performed with monitoring of the epidural pressure in a series of dogs with hydrocephalus induced with kaolin. PVL of various degrees was detected in the experimental animals, which disappeared immediately after a shunting operation. Correlations have been attempted between PVL on CT scans and histological examinations, contrast enhancement studies, metrizamide ventriculography, and measurement of regional cerebral blood flow in the periventricular white matter. PVL in hydrocephalus is considered to represent acute edema or chronic CSF retention in the periventricular white matter caused by an increase of water content. In other words, it is regarded as a sign of existing or preceding intraventricular hypertension on CT scan, and seems to be a reversible phenomenon to some extent. PVL may therefore became an indication for a shunt.

Periventricular lucency in computed tomography of hydrocephalus and cerebral atrophy.

Periventricular lucency was evaluated in the computed tomography scans of a large group of patients with hypertensive and normal pressure hydrocephalus as well as cerebral atrophy. It is confirmed that periventricular lucency is most prominent in cases of acute obstructive hydrocephalus in which the periventricular density profile pattern is often linear and steep. This linear profile is due to the disappearance of the ventricular wall as an effective barrier at the level of the superolateral angle of the frontal horn. The features of the periventricular lucency in chronic hydrocephalus (hyper- and normotensive) and cerebral atrophy are presented and discussed in detail.

Craniopharyngiomas with unusual topography and associated with vascular pathology

SummaryOut of 155 cases of craniopharyngioma seen in the past 47 years, 19 are considered unusual. These 19 cases have been placed under the following headings— 1. unusual topography, and 2. associated vascular pathology. Since CT scanning offers important information about extension of craniopharyngiomas, it is very helpful for planning operative approach. However, cerebral angiography is still important for demonstrating vascular pathology.

Intraoperative Transcranial Motor-Evoked Potentials Predict Motor Function Outcome in Intracerebral Hemorrhage Surgery

OBJECTIVE Prediction of motor function after intracerebral hemorrhage (ICH) often poses a diagnostic challenge. This study was performed to investigate whether intraoperative monitoring of motor-evoked potentials (MEPs) could predict postoperative motor function recovery. METHODS We reviewed 16 consecutive patients undergoing evacuation of supratentorial ICH with hemiplegia between June 2011 and October 2014. Patients were categorized according to the results of MEPs before and after evacuation of hematoma. The correlation between detection of MEPs and prognosis of motor function was analyzed. RESULTS In 10 of 16 cases (62%), stable MEPs were detected before and after evacuation of hematoma, and postoperative motor function was improved in all cases, including 3 cases with severe preoperative motor impairment on manual muscle test (1-2). In 3 cases (19%) in which MEPs were not detected throughout the procedure, motor function was not improved. In the other 3 cases (19%), MEPs were not measured before evacuation of ICH but were detected after evacuation despite poor prognosis of motor function. The results of postevacuation MEPs were considered false-negative results. Predictions using pre-evacuation MEP results were completely consistent with prognosis for recovery, whereas MEPs obtained during and after evaluation were useful for monitoring. CONCLUSIONS Intraoperative MEPs may indicate preservation of pyramidal tracts, and pre-evacuation MEPs can predict motor function outcome after ICH surgery.

Vertebral Angiography in Diagnosis of Traumatic Hematomas of the Posterior Fossa

Nine cases of traumatic hematoma of the posterior fossa are reported and the diagnostic value of the vertebral angiography is emphasized. 1. The diagnosis of an acute posterior fossa hematoma by physical examination is known to be difficult. It is our practice to perform emergency vertebral angiography, when the patients with occipital bone fracture develop disturbances of consciousness and changes of vital signs. We prefer preoperative vertebral angiography to exploratory trephination without angiography. 2. In five of our nine cases there were combined supra and infratentorial hematomata, all of which were found by preoperative angiographies. On the other hand there were two cases of frontal intracerebral hematoma diagnosed by angiography, whose clinical diagnosis had been posterior fossa hematoma. Retrograde right brachial angiography is an excellent mean to see both supra-and infratentorial lesions simultaneously. 3. One can differentiate a posterior fossa epidural hematoma from a subdural hematoma by angiography since an avascular area. of the subdural hematoma does not extend the cerebellar tentorium. 4. In one case extravasation of contrast medium from the posterior inferior cerebellar artery during angiography clearly demonstrated the bleeding point. In some other cases the deformity of the lateral sinus suggested the site of lateral sinus injury. In another case extravasation of contrast medium from the lateral sinus was suspected. Some surgeons feel that one should perform immediate exploratory trephination without vertebral angiography, when posterior fossa hematoma is suspected. However, we are of opinion that an emergency vertebral angiography can be performed without wasting time, while the emergency operation is being prepared. Vertebral angiography can provide invaluable informations for planning the operation about the site, size and multiplicity of the hematoma. In conclusion, it is important to have the neurosurgical service system in which emergency vertebral angiography can be performed without delay in any circumstances.

Extracranial internal carotid artery dissection caused by compression from a giant osteophyte due to atlantoaxial osteoarthritis: case report

Deformed osseous structures have been reported as rare causes of extracranial internal carotid artery (ICA) dissection, including the styloid process and the hyoid bone. Here, the authors describe the first known case of symptomatic ICA dissection caused by a giant osteophyte due to atlantoaxial osteoarthritis. The left ICA was fixed at the skull base and at the ICA portion compressed by the osteophyte, and it was highly stretched and injured between the two portions during neck rotation. The patient was successfully treated with ligation of the affected ICA following balloon test occlusion. Atlantoaxial osteoarthritis should be considered in the differential diagnosis of ICA dissection in patients with a severely deformed cervical spine.

Digital mirror box: An interactive hand-motor BMI rehabilitation tool for stroke patients

We develop a brain-machine interface for the hand-motor rehabilitation of stroke patients. The interface provides both visual and proprioceptive feedback to the user based upon the successful generation of cortical motor commands. We discuss the details of the proposed system and provide a summary of the preliminary experiment. The experiment investigates the importance of simultaneous visual and proprioceptive feedback to the delivery of motor commands from the affected motor cortex of the patients. We also discuss a case study involving a chronic stroke patient who trained with the system for 14 days to recover functional movement in the hand. The results obtained by this study suggest that the developed system is effective at accelerating the recovery of motor function in stroke patients with hand paralysis.

Pathogenesis of Periventricular Lucency on Computed Tomography

Pathogenesis of periventricular lucency was investigated. Periventricular lucency noted in acute hydrocephalus may represent periventricular edema and disappears in a short time after a shunting operation. Periventricular lucency in chronic and normal pressure hydrocephalus is presumed to be a consequence of water retention combined with a disturbance of the blood circulation in the white matter. Periventricular lucency in hydrocephalus is considered to be a reversible phenomenon and may be regarded as a sign of present or preceding intraventricular hypertension. It may provide a useful criterion for a shunting operation. Periventricular lucency encountered in diseases other than hydrocephalus is supposed to be leukoencephalopathy in the arterial borderzone which is vulnerable to hypoxic-ischemic events. These two different periventricular lucencies should be differentiated.