A simple and reproducible injection technique has been developed for inducing an in vivo experimental astrocytoma model in rats. Newborn rats were injected with a suspension of astrocytoma C-6 cells in doses ranging from 5 to 1 X 105 cells. The optimum dose of tumor cells was found to be between 104 and 105 cells, with a consistent 100% take rate seen above 1 X 104 injected cells. The injection of less than 104 cells resulted in a decreased ability to induce tumors, and a prolonged survival. The pathology was consistent with that of a glioblastoma multiforme. The tumor showed a diffuse infiltrating border, necrosis, and pseudopalisading. Light microscopy revealed undifferentiated tumor cells while electron microscopy demonstrated rough endoplasmic reticulum, Golgi complexes, mitochondria, and the occasional cilium and centriole. The nature of the astrocytoma C-6 cell line, and the advantages, disadvantages and possible uses of the model are discussed.

In a sibship of four, Friedreich’s ataxia and minimal lesion nephrotic syndrome occurred in two siblings, a third sibling had Friedreich’s ataxia, but no evidence of nephrotic syndrome; the fourth sibling had neither condition. The chance of Friedreich’s ataxia and minimal lesion nephrotic syndrome occurring in two siblings is small, and suggested a common immunological abnormality. High dose prednisone and antimetabolites given for the nephrotic syndrome did not appear to affect the course of Friedreich’s ataxia.

The two siblings with Friedreich’s ataxia and nephrotic syndrome developed epilepsy at age 15 years. All three children with Friedreich’s ataxia had abnormal electroencephalograms (EEGs). These epileptiform EEG abnormalities were probably inherited from the mother, who had spike wave epilepsy. The neurologic deficits of Friedreich’s ataxia, in turn, may have allowed the EEG trait to be expressed as a seizure disorder. The progressive ataxia and epileptic, sometimes myoclonic, seizures in these patients and the dentate nucleus changes in the autopsied patient were consistent with the diagnosis of dyssynergia cerebellaris myoclonica. This suggested that the latter disorder may represent a coincidence of two genetic entities: Friedreich’s ataxia and spike wave epilepsy.

A case is described thai illustrates the difficulties involved with the interpretation of postoperative posterior fossa CT scans. The reasons for the difficulties are discussed and the pertinent literature reviewed.

Two children, age seven and 16 years, are described with the abrupt onset of a pure motor hemiplegia as the initial manifestation of a brain stem neoplasm. Subsequent rapid neurological deterioration localized the lesion to the brain stem and glioblastoma multiforme was diagnosed by surgical biopsy. It is suggested that brain stem gliomas with this unusual presentation are likely to be highly malignant and prone to rapid bulbar deterioration.

A 54-year-old man died following a 20-year course of intermittent neurologic symptoms. He carried a diagnosis of multiple sclerosis, with most severe involvement thought to be in the spinal cord. At autopsy, two neurenteric (enterogenous) cysts were found to indent the anterior spinal cord — at the T4 and Tl I cord levels. Partial diplomyelia was present in the lumbosacral cord. These findings represent a unique combination of congenital abnormalities. Their embryogenesis and pathogenesis are discussed.

Experiments were conducted to evaluate the effect of two intertrial intervals of 1-Hz brain stimulation on kindling behavior induced by 60-Hz sine wave stimulation. In two experiments, the effective threshold intensity (ETI) to elicit a convulsion was determined on four separate occasions with 5 days of daily trials between determinations. On each day experimental rats were stimulated with 1-Hz current on the first and third trials for 120 seconds duration and with 60-Hz current for 30 seconds on the second trial (1-60-1 group). A second group was stimulated with 60-Hz current on each trial (60-60-60 group). A third group received no stimulation on Trials 1 and 3 and 60-Hz current on Trial 2 (X-60-X group). In Experiment I, the intertrial interval was 3 hours; a 24 hour interval was used in Experiment 2. The results were similar in both experiments. For the 1-60-1 group, there was a steady increase in the intensity required to elicit a convulsion with 60-Hz current from ETI to ETI. However, the 24 hour interval produced a lesser effect than did the 3 hour interval (or the 1 hour interval used in previous experiments). Rats in the other groups maintained relatively stable values from ETI to ETI, with a slight decline occurring. Suppression of convulsive behaviour on daily trials was present with the 1-60-1 groups, and nonexistent with the other groups.

Demyelination is assumed to be the cause of the majority of cases of isolated optic neuritis. Because of the importance of establishing the presence of optic nerve dysfunction in patients suspected of having multiple sclerosis several new indices of optic nerve conduction have been reported including the visual evoked potential, the edge-light pupil cycle time, and the Pulfrich test. These measures purport to detect optic nerve dysfunction but with varying degrees of success. This study of 93 patients with clearly documented previous optic neuritis was conducted to determine the statistical relationship between these three measures and other clinical diagnostic indices for detection of previous optic nerve disease and the utility of the diagnostic predictors taken individually, and in combination. The other indices used were the presence of detectable optic atrophy, color vision defect and the presence of a relative afferent pupillary defect. The variables were submitted to linear stepwise multiple regression analysis which indicated that the presence of optic atrophy, defective color vision and prolonged pupil cycle time when used in combination provided the most useful diagnostic prediction of previous optic neuritis in this group of patients. The addition of visual evoked potentials, the Pulfrich test or presence of a relative afferent pupillary defect did not significantly increase predictive reliability.

The first case of Pasteurella Multocida subdural empyema is reported. This was secondary to hematogenous spread from the pharynx to a chronic subdural hematoma. Positive cultures were obtained from the primary source, the blood and the subdural space. The patient was discharged with no neurological deficit following surgical drainage and parenteral antibiotics. The incidence, predisposing factors, clinical features, bacteriology, diagnostic procedures, treatment and mortality of subdural empyema are briefly discussed.

Dopamine (DA) uptake by platelets from 41 patients at risk to develop Huntington’s chorea was assayed and compared to controls. The DA uptake was significantly higher in the at risk group. However, the at risk group did not separate into two distinct subgroups. which reduces the usefulness of the assay as a disease prognosticator.

Swollen, degenerate and fragmented neurons of the septal nuclei and the nucleus ansae peduncularis are commonly found in chronic neurological diseases such as Alzheimer’s or Huntington’s disease, and are rarely found in neurologically normal control patients without mental symptoms. These pathological lipid and pigment laden neurons appear to be a common feature of schizophrenia and have been consistently found in a series of unselected young (mean age 38) schizophrenics.

Five myasthenia gravis patients with post-thymectomy residual ocular signs were treated with plasmapheresis. Despite a significant reduction in AChR antibody titer, there was no clinical improvement. Subsequently, there was a dramatic response to prednisone. The AChR antibody titer did not correlate with the clinical state of the individual patient. It is suggested that plasmapheresis may operate by removing a thymic factor and that prednisone acts by a different mechanism.

The case history and CT scan of a patient with delayed encephalopathy following carbon monoxide intoxication are described. The patient recovered.

The CT scan revealed symmetrical areas of decreased density at the level of the globus pallidus. This case differs in several ways from other cases of carbon monoxide intoxication in which abnormalities of the CT scan were found.