[Value of gadolinium magnetic resonance imaging of the lumbosacral roots in acute polyradiculoneuritis]. / Intérêt de l'imagerie en résonance magnétique avec gadolinium des racines lombo-sacrées dans les polyradiculonévrites aiguës.

Four patients with acute inflammatory polyradiculoneuropathy were evaluated with MRI. In 3 of 4 cases, gadolinium enhancement was observed in the nerve roots of cauda equina, on frontal and horizontal slices. This enhancement was correlated with the severity of the clinical picture and the cerebrospinal-fluid inflammatory protein concentration and supports the inflammatory nature of this forms of acute polyradiculoneuropathy.

Late thalamic atrophy in infarction of the middle cerebral artery territory in neonates. A prospective clinical and radiological study in four children.

We report four cases of progressive thalamic atrophy following ipsilateral cerebral infarction in the territory of the middle cerebral artery in neonates, with prospective radiological and clinical follow-up. This type of atrophy appears within 6 months after the onset of cerebral infarction. In the short term, this atrophy has no action on sensory and memory function and/or on sensory evoked potentials. This atrophy is not the result of secondary ischemic neuronal damage. Judging from several other experimental studies, thalamic atrophy may primarily result from retrograde degeneration. It would be interesting to observe the consequences of this atrophy on sensory and memory function over a long period.

Preliminary observations of metabolic characterization of bilateral temporal epileptic focus, using proton magnetic resonance spectroscopy. Three cases.

The authors report the case of 3 patients with bilateral temporal lobe epilepsy demonstrated by EEG and sphenoïdal electrodes. Two out of the 3 patients presented with childhood febrile convulsions. Their neurological and mental examination was normal. EEG showed spikes within the anterior part of the 2 temporal lobes. CT scan and MRI showed no atrophic lesion within the 2 temporal lobes. Proton magnetic resonance spectroscopy, performed within a cube of 8 cube-centimetres localized in the anterior part of the 2 temporal lobes showed a significant decrease of N-acetyl-aspartate in the 2 temporal lobes of the 3 cases, compared with controls matched with age, sex and laterality. Because N-acetyl-aspartate is a marker of the neuronal cells, the decreased level of NAA in the temporal area with spikes, may be related to a decreased number of neuronal cells, developing an abnormal tendency to seizures.

So-called generalized epilepsy in children leading to frontal epilepsy with a frontal syndrome in adulthood: a clinical, EEG and radiological study of 10 cases.

The authors report 10 cases of epileptic patients with the onset in childhood of the clinical and EEG features of cryptogenic generalized epilepsy which evolved into frontal epilepsy, confirmed by the clinical and EEG features and was associated with a frontal syndrome. CT-scan and MRI showed mild atrophy in the frontal area, while SPECT showed a decrease in the frontal blood flow in 70% of the cases. The authors consider that frontal epilepsy may mimic generalized epilepsy.

[Lissencephaly. Clinical, electroencephalographic and radiological aspects]. / La lissencéphalie. Aspects cliniques, électroencéphalographiques et radiologiques.

We report 2 cases of lissencephaly and review the cardinal symptoms: microcephalia, mental retardation, pyramidal syndrome and generalized epilepsy. CT-Scan and MRI show the anatomical abnormalities of this malformation: microcephalia, smooth cortex reducing the surface of white matter and lack of sulci and gyri. The fact that the myelin is normal on MRI suggests that this major disorder of neuronal migration does not come from radial glial fibers.