Shinya Manaka

Three-dimensional digitizer (neuronavigator): New equipment for computed tomography-guided stereotaxic surgery

A new device was invented as an adjunct for computed tomography (CT)-guided stereotaxic or open neurosurgery. It is composed of a multijoint three-dimensional digitizer (sensor arm) and a microcomputer, which indicates the place of the sensor arm tip on preoperative CT images. Computed tomography scan is performed preoperatively with three markers placed on the nasion and ears. At surgery, after fixing the patients head and the sensor arm, sampling of the standard points was done to translate the position of the tip of the sensor arm onto the CT images displayed on a computer screen. In this way positional data from conventional preoperative CT scan can be directly transferred into the surgical field. This system has the unique feature of introducing CT-guided stereotaxis into conventional open neurosurgery.

Spontaneous intracranial hemorrhage caused by brain tumor: its incidence and clinical significance.

Hemorrhage from brain tumor was confirmed clinically, surgically, or on autopsy in 94 of 1861 cases (5.1%) treated during the past 18 years: 49 of 311 pituitary adenomas (15.8%) and 45 of 1550 other brain tumors (2.9%). The higher incidence of hemorrhage from pituitary adenoma was statistically significant (p less than 0.001). In brain tumors other than pituitary adenoma, the incidence of hemorrhage was significantly higher in the patients under 14 years old (17 of the 322 cases, 5.3%) than in the patients over 15 years old (28 of the 1228 cases; 2.3%) (p less than 0.001). Nineteen patients showed no evidence of clinical symptoms related to bleeding. Twenty-six patients had a definite history of an acute episode that suggested sudden bleeding. In 11 of these, the apoplectic syndrome was the initial presenting symptoms. The incidence of hemorrhage was not statistically correlated with sex. The hemorrhage was intratumoral in 30 cases, intracerebral in 7, subarachnoid in 7, and subdural in 1. The tumors were supratentorial in 36 cases, pineal in 1, and infratentorial in 8. Primary and metastatic choriocarcinoma and primary embryonal carcinoma seemed to cause hemorrhage most frequently. The following precipitating factors were found in 7 of the 17 patients aged under 14: ventricular drainage in 2, ventriculoperitoneal shunt in 2, carotid angiography in 1, head injury in 1, and leukemia in 1. Seven of the 17 patients under 14 years old died of massive bleeding from the tumor. Unless there is evidence of vascular disease such as cerebral aneurysm, vascular malformation, or hypertensive cerebrovascular disease, intracranial hemorrhage should be suspected of being due to a brain tumor.

Clinical Course and Surgical Prognosis of 33 Cases of Intracranial Epidermoid Tumors

Thirty-three cases of intracranial epidermoid tumors treated during the past 25 years were analyzed with regard to clinical manifestations, recurrence rates related to the extent of surgery, and long-term survival rates. Epidermoid tumors caused various symptoms, especially in the cerebellopontine angle (15 cases), of which a transient remission of symptoms was observed in 4 cases (23.5%). The average time from initial symptoms to surgery was much shorter in suprasellar region and third ventricular locations (average of 11 months) than in other locations (average of 7 years). In 28 patients (84.9%), the tumor was removed totally or subtotally. Most of the patients could lead an independent and useful life after operation (93.1%). Among the 29 patients in a long-term follow-up survey, seven tumors recurred after an average interval of 8 years and 10 months (from the first to second operation) and 12 years and 6 months (from the second to third operation). Patients with recurrent tumors were successfully treated, and excellent functional prognosis was observed even after the second or third operation. The 20-year survival rate was 92.8% (Kaplan-Meier method).

Estimation of intracranial pressure using computed tomography scan findings in patients with severe head injury

The relationship between initial intracranial pressure and the findings of the first computed tomography scan on admission was assessed in 100 consecutive moderate-to-severe head injury patients using a method of multiple regression analysis. Intracranial pressure was measured through a slender subarachnoid catheter with a transducer. Thirty-nine checkpoints of computed tomography findings, including a shift of midline structure, the status of ventricles or cisterns, and the amount of subarachnoid hemorrhage, were investigated. The results were as follows: (1) The computed tomography findings that contributed to estimating intracranial pressure were the appearance of cisterns, the size of a subdural hematoma (number of slices), ventricular size, status of subarachnoid hemorrhage, status of cerebral contusion, magnitude of midline shift, and ventricular index, in that order. (2) Approximately 80% of predicted cases of intracranial pressure were included within the range of measured intracranial pressure +/- 10 mmHg. When the predicted intracranial pressure was less than 30 mmHg, the discrepancy between both intracranial pressures was small. It is concluded that an equation using several computed tomography findings gives a reasonably accurate intracranial pressure for the initial stage of severe head injury.

Thyrotropin-Releasing Hormone Tartrate (TRH-T) shortens concussion effects following head impact in mice

Abstract Thyrotropin-Releasing Hormone tartrate (TRH-T) given in dosage levels of more than 0.16 mg/kg improved with statistical significance the concussion-like disturbance of behavior caused by head impact in mice. It is suggested that TRH exerts its effects through mediation via monoamines.

Mechanism of action of CDP-choline in parkinsonism

Es ist anzunehmen, dass CDP-Cholin (Cytidin-Diphosphat-Cholin) auf Verminderung von Dopamin im Nucleus caudatus einen signifikanten (0.001<p<0.01) Abwehreffekt ausübt, was durch homolaterale Destruktion der Substantia nigra verursacht wird.

Spatial Distribution of Brainstem Auditory Evoked Potentials and Their Alterations in Lesions of the VIIIth Nerve and Brainstem1

AbstractBrainstem auditory evoked potentials (brainstem AEPs) were simultaneously recorded from 13 scalp and earlobe electrodes from normal subjects employing a noncephalic reference. The scalp distributions of the individual components (waves I-V) were presented as isopotential maps with the use of a topographic computer display system. Binaural clicks produced symmetrically distributed brainstem AEPs over the scalp. With monaural stimulation, the topography of the responses differed in locus of maximum amplitude for each of the components, suggesting that different generators are involved in the production of these components (for example, wave V is of maximal amplitude with the shortest peak latency over the contralateral frontal area). Wave I was the only component that reversed its polarity according to electrode locations. Other waves were positive over the scalp and earlobes in confonnity with the concept that they are volume conducted, far field potentials. Brainstem AEPs in subjects with lesions ...

Nocturnal dyspnea treated by diaphragm pacing

A case of nocturnal dyspnea secondary to atlantoaxial dislocation is reported. Noctural dyspnea was not alleviated by a decompressive laminectomy of C-1 and a half of C-2 vertebrae made by a transoral pharyngeal approach. Diaphragm pacing at night was effective for the longterm management of nocturnal dyspnea.

The role of extracellular potassium in early epilepsy.

Clinical studies indicate that early epilepsy after injury may be associated with some transient and reversible pathophysical processes of the brain. It has been proposed that epileptogenesis in the neocortex and hippocampus may be related to potassium ion accumulation in extracellular spaces. To investigate this hypothesis, we measured [K+]0 using potassium-sensitive microelectrodes in the sensorimotor cortex of cats during early seizures induced by trauma. The [K+]0 increases associated with seizure activity ranged from 14.6 to 25.1 mM, and these were significantly higher than those unassociated with spikes or seizure discharges. Moreover, high K+ solutions (15 mM or more) directly applied to the cortex produced spiking and seizures. These results seem to support the hypothesis that accumulation of [K+]0 is related to development of early epilepsy.

The Difference between Children and Adults in the Onset of Post‐Traumatic Epilepsy

Abstract: In order to clarify the difference between children and adults in the onset of post‐traumatic epilepsy, 96 outpatients of our clinic were investigated statistically. The subjects comprising 40 children and 56 adults were followed up for more than three years. The latency of the children, i.e., the interval between a head injury and the onset of epilepsy, was longer than that of the adults. The 95%‐confidential interval classified by age group indicated that the upper limits of latency of the group under the age of two, those between three and 14 and those aged more than 15 were about 13, six and three years, respectively. We concluded that children with a severe head injury should be followed up until the age of 20 and adults for about three years.