Prenatal cytomegalovirus disease and cerebral microgyria: evidence for perfusion failure, not disturbance of histogenesis, as the major cause of fetal cytomegalovirus encephalopathy.

From the study of four personal cases of microgyria related to fetal CMV infection and a review of the literature it is concluded that: 1) Microgyria is a frequent neuropathological finding in this disease - 2) CMV microgyria is the result of an insufficiency of cerebral blood supply and is not due to a disturbance of neurogenesis or histogenesis as a consequence of a direct cytopathic effect of the virus on germinal cells. The way by which the CMV causes cerebral ischemia - angeitis or more probably, transient systemic perfusion failure, - is discussed, but remains obscure. Other viruses may act on the fetal brain by way of circulatory disturbances.

[Joubert syndrome. Clinical and anatomo-pathologic study. Etiopathogenetic hypotheses]. / Le syndrome de Joubert. Etude clinique et anatomo-pathologique. Hypothèses étiopathogéniques.

Joubert's syndrome is characterized by an agenesis of the vermis and an unique respiratory abnormality consisting of bouts of extreme tachypnea and prolonged apneas. Three patients with this syndrome are reported with a polygraphic study and a recording of intracranial pressure in one of them and a pathological study in another. It is suggested that the agenesis of the vermis is caused by a prenatal hydrocephalus as is probably the case in the Dandy-Walker syndrome. A comparison is established between these two syndromes. The periods of tachypnea-apnea could represent the persistence of a fetal pattern of respiration with an excessive response to various stimuli, and might be explained by the delayed maturation of inhibitory mechanisms necessary for the establishment of the normal pattern of respiration and sleep. The possible role of a total vermian agenesis in the pathogenesis of respiratory abnormality is discussed.

Ependymitis, leukoencephalitis, hydrocephalus, and thrombotic vasculitis following chronic infection by mouse hepatitis virus 3 (MHV 3).

Mouse hepatitis virus 3 (MHV 3) is either avirulent (resistant mice), hepatotropic (susceptible mice), or neurotropic (semisusceptible mice), depending on the strain of mice infected. In semisusceptible mice, infection led first to a transient meningitis, ependymitis, and leukoencephalitis, followed by a permanent communicating hydrocephalus and, later on, to a chronic thrombotic vasculitis affecting meningeal and parenchymal vessels at the brain stem level. Small foci of ischemic necrosis related to vascular occlusions were seen in the dorsal brain stem. Cyclophosphamide treatment of semisusceptible mice significantly reduced the meningeal infiltrates but did not prevent the development of hydrocephalus and other neuropathologic changes. Identical lesions occurred in fully susceptible mice infected with a low dose of virus, but no neurologic disorder could be induced in genetically resistant mice even following immunosuppression or intracranial inoculation. The leukoencephalitis differed from the demyelinating lesions observed with MHV 4. Vascular lesions were of particular interest. More attention should be given to the possibility of virus induced chronic cerebral vasculitis in man.