Spontaneous calcific cerebral emboli from calcified aortic valve stenosis.

Calcific cerebral emboli (CE) are a rare complication of calcified aortic valve stenosis (CAS). These emboli usually result from diagnostic manoeuvres (e.g. left heart catheterization) or from therapeutic procedures (e.g. heart valve surgery). Spontaneous calcific emboli are exceptional. We present the cases of two subjects known to have CAS who presented with acute neurological disorders suggesting strokes. In both subjects CT scans of the skull and brain provided a diagnosis of spontaneous CE by showing calcium-dense dots located on vessels or within the cerebral parenchyma. Additional examinations enabled us to determine the origin (heart or carotid artery) of these emboli. The finding of spontaneous cerebral CE is a very strong argument in favour of surgical valve replacement in these patients.

[Functional neurosurgery of chronic pain: nociceptive tracts ablation at the level of the peripheral nervous system and spinal cord]. / Neurochirurgie fonctionnelle de la douleur chronique: interruptions des voies nociceptives au niveau du système nerveux périphérique et de la moelle épinière.

This article is devoted to ablative neurosurgical procedures used for the treatment of chronic pain. The procedures are classified as those directed to the cranial nerves, the peripheral nerves, the spinal roots, the dorsal root entry zone and the ascending spino-reticulo-thalamic pathways. The rational and neurophysiological effects of these operations are stressed. The actual indications for each procedure are specified.

[Contribution of magnetic resonance imaging in 100 cases of refractory partial epilepsy with normal CT scans]. / Apport de l'imagerie par résonance magnétique dans 100 cas d'épilepsie partielle rebelle à scanner X normal.

One hundred epileptic patients were included in this study according to the following criteria: intractable partial epilepsy, normal CT scan and focal EEG abnormalities. Eighty-nine patients were suffering from complex partial seizures of temporal or frontal origin, 55 and 34 cases respectively. Eleven patients presented with only simple partial seizures. MRI was abnormal in 31 patients. The abnormalities were: focal T2 increased signal intensity (13 cases) most often temporal (10 cases), cryptic arteriovenous malformation (4 cases), focal T1 and T2 signal abnormality (4 cases), focal atrophy (2 cases) and multiple abnormal T2 signals scattered in the white matter (8 cases). The site of MRI abnormalities was consistent with electroclinical data in 22 patients, of whom 20 had a temporal lobe epilepsy. Thus MRI proved to be more often abnormal in temporal than in frontal lobe epilepsy (36 p. 100 and 5.9 p. 100 respectively) when the CT scan is normal. However MRI data, particularly focal T2 hypersignals should be confronted to electroclinical and metabolic findings whenever functional surgery is considered.

Magnetic resonance imaging in refractory focal epilepsy with normal CT scans.

One hundred patients suffering from focal epilepsy with complex partial seizures refractory to medical treatment and showing no abnormality at CT were explored by MRI with an 0.5 Tesla magnet. MRI detected an abnormality in 25 patients with, in 17 of them, good correlation between MRI and clinical as well as electroencephalographic findings. Abnormal morphology and signal was found in 5 patients, with positive CT results on reexamination of previous CT images or on new CT scans in 4 of them. There was a diffuse temporal lobe high-intensity signal in 3 cases and a localized high-intensity signal in 9 cases (temporal lobe 4, occipital lobe 3, frontal lobe 1, fronto-parietal and parietal lobes 1). Thus, in 13% of the cases MRI demonstrated a lesion that had not been detected at CT, and the location of the lesion was concordant with clinical and electroencephalographic data.

[Hydrocephalus and brainstem tumor of late manifestation]. / Hydrocéphalie et tumeur du tronc cérébral de révélation tardive.

We report two clinico-pathological cases with an initially hidden brainstem tumour presenting as chronic hydrocephalus of "idiopathic type". Diagnosis was established respectively one and two years after a successful shunting procedure, as repeated CT scan was performed because of gait deterioration. The first case was a bifocal glioblastoma invading the leptomeninges of the posterior fossa and spinal cord, and resulting in a communicating hydrocephalus. The second case was an ependymoma of the fourth ventricle leading to e non-communicating hydrocephalus. Rarity of such cases is emphasized.