Perilymphatic fistula--a definitive and curable cause of vertigo following head trauma.

Vertigo or disequilibrium occurring in patients after concussive and nonconcussive head trauma may be due to a pathologic perilymphatic fistula from the inner ear through the oval and round window areas of the middle ear. Of 33 patients who had successful grafting of the fistulous area at middle ear exploration, 32 had resolution of vertigo, and 12 of 23 who had an associated hearing loss had improved hearing. Perilymphatic fistulas associated with vertigo and hearing loss after head trauma can be diagnosed with great certainty and are surgically curable in the great majority of cases. Patients with post-concussive syndrome, whose symptoms include vertigo or disequilibrium, should have a thorough otologic evaluation for the possibility of a perilymphatic fistula.

Paraganglioma in the cauda equina region.

Some new ultrastructural observations are documented in paraganglioma in the cauda equina region. These include the presence of nerve fibers in the tumor capsule, clear vesicles and tubulo-vesicular structures in some cytoplasmic processes in the tumor, fenestrated endothelial cells, and numerous tubular bodies in some endothelial cells.

Arteriovenous malformations of the spinal cord.

Spinal AVM's are not rare, and are diagnosed today with increasing frequency by utilization of moedern neuroradiological techniques. Their relationship to the spinal medulla is related to vascular embryological anatomy, and the only effective treatment is directed at obliteration of the fistula. Males are affected more frequently in the middle years of life. Symptoms may mimic spinal cord tumors and demyelinating disorders. The pathogenesis of symptoms, classification, and methods of diagnosis are reviewed, and the various methods of treatment discussed.

A pre-formed methyl methacrylate cranioplasty.

The use of a pre-formed methyl methacrylate cranioplasty prosthesis reinforced with stainless steel wire is described. The prosthesis is non-reactive, virtually unbreakable, and undentable. Pre-forming of the prosthesis in the dental laboratory using a mold of the patient's bony defect as a model saves considerable operating time, and when employed for a large cranial defect the three dimensional cosmetic effect is superior to intra-operatively fashioned prostheses.

Disc space infections in children.

Intractable low back pain in children is often due to disc space infections. The clinical presentation, diagnostic workup, and treatment of four cases are presented. Symptoms often occur well before radiographic findings are evident. The diagnosis can only be made by a high degree of suspicion and repeated X-rays. Antecedent causes, such as urinary infection or intravenous administration of narcotics were lacking in this group. Fever or a preceding febrile illness was often, but not invariably, present. Percutaneous biopsies were not usually helpful. Myelography in each instance was normal. Bed rest reduced but did not alleviate the back pain. The institution of appropriate antibiotic therapy resulted in a prompt diminution of pain.

Distal shunt herniation simulating testicular torsion.

A case of herniation of the catheter of a peritoneal shunt into the scrotum is reported. Infection of the catheter caused scrotal inflammation simulating torsion of the testicle.

Hydrocephalus: III. Reconstitution of the cerebral cortical mantle following ventricular shunting.

Adult cats with hydrocephalus were sacrificed at varying times following valveless ventricular shunting. This shunting resulted in a prompt reduction of ventricular size and rapid gross reconstitution of cortical mantle. Ultrastructurally it was evident that white matter edema persisted for many weeks, even in the presence of normal size ventricles. The areas most severely affected by the hydrocephalus such as the corpus callosum showed a paucity of myelinated fibers and their replacement by numerous reactive astrocytes. Reconstitution of the cortical mantle consists predominantly of a diminution of white matter edema and reactive astrocytosis. Clinical improvement undoubtly results from the functional improvement of remaining elements rather than from the replacement of lost elements. This scheme of hydrocephalus suggests that if hydrocephalus is relieved when only ependymal disruption and periventricular water accumulation have occurred, it may be reversible. The subsequent sequence of events consisting of axonal degeneration, myelin disruption and reactive astrocytosis may be less, if at all reversible.

Hydrocephalus: I. Histological and ultrastructural changes in the pre-shunted cortical mantle.

Hydrocephalus results in a reduction in the thickness of the cerebral cortical mantle which seemingly is restored by ventricular shunting. In order to determine the effect of hydrocephalus and its potential reversibility, experimental hydrocephalus was produced in adult cats by the introduction of kaolin or silicone into the basal cisterns followed by bilateral craniectomies. Microscopic and fine structural studies of these animals suggest the occurrence of significant focal axonal destruction. These studies suggest a sequence of events consisting of ventriculomegaly, disruption of the periventricular ependyma, periventricular edema, axonal destruction, secondary myelin disintegration and finally reactive astrocytosis. The damage to axons and meylin and resulting gliosis is irreversible.

Hydrocephalus: II. Cell number and size, and myelin content of the pre-shunted cerebral cortical mantle.

The number of cells in the brain and their size can be calculated by determining the total brain DNA, RNA and protein. Myelin can be determined biochemically. This analysis was applied to brains of a group of adult cats with craniectomies that were made severely hydrocephalilc by the introduction of kaolin or silicone into the basal cisterns. In severely hydrocephalic brains sectioned rostral to the area of kaolin inflammation there was no loss of dry weight. Wet weight increased slightly reflecting periventricular edema. There was a slight increase in total DNA, RNA and protein, presumably reflecting the increase in small inflammatory cells. There was a significant reduction in galactolipids reflecting myelin loss.

Reconstitution of the cerebral cortical mantle in shunt-corrected hydrocephalus.

The purpose of this study was to ascertain the sequence of events and the cellular constituents involved in reconstituting the cortical mantle after ventricular shunting. The subjects were severely hydrocephalic adult cats. After insertion of a shunt, the ventricular system rapidly returned to normal size and there was gross reconstitution of the cortical mantle. However, there still remained in the cortical mantle many of the histological changes seen before insertion of the shunt. The effect of hydrocephalus is mainly upon axons in the periventricular white matter. The axons become stretched and finally disrupted, resulting in disintegration of the surrounding myelin. In the absence of axons, remyelination cannot take place. It would seem, therefore, that prompt reversal of hydrocephalus is necessary in order to preserve the anatomical and functional integrity of the brain.