Diffuse Axonal Injury : Changes of Cerebral Blood Flow, Intracranial Pressure and Evoked Potentials

Fifteen cases of diffuse axonal injury(DAI) brought about by nonmissile head injury in humans are analyzed. All cases were subjected to comprehensive clinical studies such as measurement of cerebral blood flow by SPECT, continuous intracranial pressure monitoring and multimodality evoked potentials(MEPs). In the patients with DAI, a high incidence of low cerebral perfusion and abnormal MEPs. especially auditory evoked potentials, were found, with high incidence of high velocity traffic accident injury mechanism. On the other hand, a low incidence of increased intracranial pressure was found and dehydrating agents such as glycerol and mannitol did not exert a beneficial influence upon the clinical courses or the outcomes. The outcome of the patients with DAI depended upon the duration of coma and whether or not brain stem signs were noted.

Thoracic Spinal Canal Stenosis Caused by Degenerative Hypertrophy of Posterior Elements: An Analysis of 21 Surgical Cases

Twenty-two surgical cases of myelopathy due to narrow thoracic spinal canal associated with degenerative changes of the posterior spinal elements have ever been reported in the literature since Govoni presented the first cases in 1971. Authors have experienced five surgical cases and added them to the above twenty-two cases. And clinical analysis was made with twenty-one cases, which had proper data to be analysed and included our own five cases. Thirteen patients were male and the average age was around fifty-five years. Most of the lesions were found in the lower thoracic spines and involved single segment in each patient. The symptoms were so various and non-specific that pertinent treatments were delayed and the disease had been misdiagnosed in most of the patients. Intrathecal enhanced spine CT might be most accurate diagnostic tool. Surgical decompression may proceed good results, even when symptoms have been presented for years.

Somatosensory Evoked Potentials in Ventricular Enlargement of Experimental Hydrocephalus

We investigated the somatosensory evoked potentials(SEPs) changes and subsequent changes of the ventricular enlargement in different stages of kaolin-induced hydrocephalus. 8 week-old fifty five cats weighing 900g to 1300g, were studied in this experiment. These animals were divided into 2 groups ; a normal control(5 cats), kaolin-induced hydrocephalic groups(50 cats). The kaolin-induced hydrocephalic groups were subdivided into 5 subgroups of 10 cats each ; kaolin induced 1,2,4,6 and 8 weeks hydrocephalic groups after an intracisternal injection of the kaolin. At the each stage of the kaolin-induced hydrocephalic animals, the following parameters were obtained ; somatosensory evoked potentials(SEPs) and the size of enlargement of the ventricles at the each stage of 1,2,4,6 and 8 weeks after intracisternal kaolin injection. The results were as follows: 1) A significant elevation of the intracranial pressure(ICP) was observed in 2 weeks after kaolin injection and peak value(ICP : 10.2+/-0.9mmHg) in 4 weeks after kaolin injection. 2) The mean latencies of these wave components in somatosensory evoked potentials(SEPs) responses were 6.27+/-0.12 msec in Po, 8.41+/-0.25 msec in No, and 12.55+/-0.36 msec in P1 and the mean central conduction time(P1-P0) was 6.10+/-0.16 msec in the normal control animals. 3) Changes of amplitude and latency in SEPs were more prominent in 4 weeks after kaolin injection and progressively prolonged latencies of each wave components and CCT were resulted in 6 and 8 weeks after kaolin injection. 4) In hydrocephalic animals, the size of the ventricle(septum pellucidum (SP)-caudate nucleus(CN) distance) was moderately increased to 5.19+/-0.43mm in 1 week after kaolin injection and continued to increased in maximum size up in the 4th week after injection. However there was no further increase in ventricular size after 4th weeks. 5) A close correlation was found between SEPs and ventricular enlargement at the each stage of kaolin-induced hydrocephalic animals. In conclusion, it is assumed that the detection of SEPs in hydrocephalus is a quite valuable prognostic tool to evaluate the functional integrity of the nerve conduction system near the paraventricular area which might be involved in ventricular enlargement.

The Pre-operative Assesment for Shunt Surgery in Normal Pressure Hydrocephalus

Normal pressure hydrocephalus(NPH) is defined as a combination of dementia, gait disturbance and/or urinary incontinence, hydrocephalus on C-T scan, with a normal intracranial pressure. The clinical effect of CSF shunting in patients with this syndrome is sometimes striking but generally only 50-60% of the shunted patients benefit from the treatment. So many pre-operative investigations are performed including clinical examination, computed tomography, R-I cistrnography, T1/2 calculated from ventricular volume pressure curve and lumbar drainage. Among the pre-operative investigations, the effect of preoperative lumbar drainage was the most reliable indicator of NPH. The possible mechanisms of improved case are proposed. The differential diagnosis of primary brain atrophy and NPH can be made by the effect of pre-operative lumbar drainage.