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One case of CJD with severe involvement of the white matter is discussed. The patient was admitted after a 3-month clinical course with rapidly increasing mental deterioration, coma vigil-like state, myoclonic twitching of the limbs and of the facial muscles. The EEG showed the typical features of CJD. The first CT scan, performed 3 months after onset, revealed only a mild cortical and subcortical atrophy of the brain. The second CT scan, 12 months later, showed a considerable cortical and subcortical atrophy of the brain. The patient died 18 months after onset. Neuropathological examination showed a severe degeneration in the gray matter, with spongiosis, loss of neurones and hypertrophic glial reaction. The white matter was also involved with severe spongiosis, demyelination and hypertrophic glial proliferation. The case is discussed in relation to the data in the literature. It is argued that cases of CJD with severe involvement of the white matter should be classified as a new neuropathological subentity of CJD.

The intracerebroventricular injection of 0.5 mg of vincristine sulphate in adult male Wistar rats caused within 11 days the impairment of motor and reflexive behavior, evaluated by the elevated platform and hanging wire tests, a decrease in food consumption and loss of body weight, a 45% decrease in hippocampal choline acetyltransferase (ChAT) activity and a 35% decrease in the rate of high-affinity choline uptake (HACU) in the injected side. The latter effects are due to the death of neurons in the respective hemiseptum. Intrafimbrial injection of vincristine caused the same decrease in ChAT activity without behavioral alterations. Daily i.p. administration of GM1 ganglioside, beginning immediately after the vincristine injection, prevented dose dependently the decrease in ChAT activity and HACU rate. Prevention was complete with the 60 mg/kg dose. The same dose was equally active on ChAT activity when given s.c. but was inactive p.o. The ChAT decrease was also prevented when GM1 treatment began 5 days after vincristine. GM1 60 mg/kg i.p. also reduced the behavioral toxicity of vincristine. The possibility that GM1 might prevent vincristine toxicity by antagonizing its disruption of neurofilaments and axonal flow is discussed.

The modulatory inputs of the cholinergic neurons of the nucleus basalis have been investigated in midpontine transected and freely moving rats by measuring acetylcholine release from the cerebral cortex using the cortical cup technique. Acetylcholine release was found to be the same in both groups of rats indicating similar levels of activity of the cholinergic neurons ascending to the cortex. The electrical stimulation of the nucleus basalis was always followed by an increase in acetylcholine release. Conversely, in some experiments only the stimulation of the midbrain reticular formation enhanced acetylcholine output. The stimulation of the nucleus accumbens prevented the increase in acetylcholine release elicited by amphetamine. The dose-dependent increase in acetylcholine output following IP administration of amphetamine was also prevented by the 6-hydroxydopamine induced degeneration of the dopaminergic fibres. However injection of apomorphine in the nucleus basalis did not modify acetylcholine output. Direct injection of the GABAergic agonist muscimol resulted in a decrease in acetylcholine output which was prevented by picrotoxin. In conclusion, the cholinergic neurons ascending to the cortex can be inhibited by GABA receptors located in the nucleus basalis and stimulated indirectly by dopaminergic fibres.

Different degrees of cerebral calcifications together with encephalofacial angiomatosis and seizure disorder characterize the Sturge-Weber syndrome. According to the observations reported in the literature, calcium deposits may be found in the wall of cerebral vessels, in the perivascular tissue and rarely within the neurons. Corresponding to the variety of localizations, the interpretation of the phenomenon remains obscure. Most theories postulate the role of a vascular factor and of a mesenchymal factor. Ultramicroscopic studies of the specimens obtained in 2 children with the Sturge-Weber syndrome provided the following findings. A mucopolysaccharidic substance constitutes the substratum for the deposition of calcium. Small amounts of this substance and calcium deposits may be detected within the connective tissue of cerebral vessels precociously; later on, while increasing in size and calcium concentration, they obviously migrate to outside the vessels. Successively, the calcium deposits seem to localize around the blood vessels. In our opinion, these observations stress the role of a primitive vascular factor; consequently, anoxia, necrosis of cerebral tissues, and variation in the calcium ion concentration would act only as secondary factors.

One case of CJD with severe involvement of the white matter is discussed. The patient was admitted after a 3-month clinical course with rapidly increasing mental deterioration, coma vigil-like state, myoclonic twitching of the limbs and of the facial muscles. The EEG showed the typical features of CJD. The first CT scan, performed 3 months after onset, revealed only a mild cortical and subcortical atrophy of the brain. The second CT scan, 12 months later, showed a considerable cortical and subcortical atrophy of the brain. The patient died 18 months after onset. Neuropathological examination showed a severe degeneration in the gray matter, with spongiosis, loss of neurones and hypertrophic glial reaction. The white matter was also involved with severe spongiosis, demyelination and hypertrophic glial proliferation. The case is discussed in relation to the data in the literature. It is argued that cases of CJD with severe involvement of the white matter should be classified as a new neuropathological subentity of CJD.

A neuropathological study was carried out in 4 cases of ischemic stroke with leuko-araiosis (LA), 3 cases of clinically suspected Binswanger's subcortical arteriosclerotic encephalopathy (SAE) also showing LA, and 3 cases without LA. Unlike the SAE cases, in 3 of the cases in the first group the white matter changes corresponding to LA could not be explained by ischemic mechanisms related to small vessel changes.

The results of 3 computed tomography (CT) examinations carried out over a 7 year period and of a post-mortem magnetic resonance (MR) study showed aspects of a white matter disease in a hypertensive patient suffering from vascular dementia. Histopathology revealed the primary cause of dementia to be a white matter degeneration sparing the U fibers. Rarefaction of both the myelin sheaths and the axons was present together with severe thickening of the medullary arteries. These findings support the existence of Binswanger's disease (BD) as a distinct variety of arteriosclerotic dementia. CT and MR imaging are valuable aids for diagnosis. However, since there are many other causes of CT and MR demonstrated diffuse white matter degeneration in the elderly, a conclusive diagnosis of BD requires pathological confirmation.

Two form of retinoic acid (RA) prevented the development of experimental allergic encephalomyelitis (EAE) in Lewis rats. RA suspended in corn oil was given before the expected onset of the disease to rats immunized with myelin and to controls. The drug suppressed the neurological symptoms as well as the perivascular infiltrates observed in vehicle treated animals. The results indicate that, under these experimental conditions, RA has immunosuppressive activity by interfering with the efferent phase of the immune response.

Administration of retinoic acid (RA) prevented the development of experimental allergic encephalomyelitis (EAE) in Lewis rats. RA suspended in corn oil was given for 3 days before the expected onset of the disease to rats immunized with myelin and to controls. The drug suppressed the neurological symptoms as well as the perivascular infiltrates observed in vehicle-treated animals. The results indicate that under these experimental conditions, RA has immunosuppressive activity by interfering with the efferent phase of the immune response.

Light and electron microscopic features of four arachnoid cysts in children are presented. The wall of the cyst appeared composed of a dense collagen tissue in which dark and clear cells were intermingled without any specific arrangement. Abutting onto this membrane, at the luminal surface, these cells were arranged in layers. Tight junctions between arachnoid cells were absent. It is suggested that the arachnoid cysts derive from a developmental aberration of the meninges.