[Nuclear magnetic resonance and cochlear implant].

Chou underlined that ive potential effects may be anticipated if MRI is realized on implantees: 1) force on the implant by strong magnetic field, 2) current induced by the implant in the radiofrequency (RF) field, 3) damage of implant by RF exposure, 4) MRI image distortion caused by the implant, 5) implant and adjacent tissue heating due to the absorption of RF energy. We studied the reality of the four first of these risks on the Digisonic cochlear implant from MXM using the Siemens Magneton 42 SP, which supplied the implants during 10 minutes with 1 Tesla magnetic field, RF 42 MHz, maximum intensity 10 kV. During T1 and T2 sequences we could notice that: 1) Provided the receiver is strongly attached in its skull niche as requested by normal surgical procedure, no deplacement may be observed: 2) No adverse current may been observed as well on the implanted electrodes as in the internal circuitry; 3) No damage or adverse magnetisation have been detected in the 3 studied receivers; 4) Cerebral imaging of the animal is moderately darkened by the implant.

[General review of deglutition. Anatomy, physiology and principal pathological disorders. Diagnostic and therapeutic contribution of imaging].

Disorders of deglutition are a relatively frequent, serious, sometimes fatal symptom, representing a major cost for society. Their frequency is currently increasing in parallel with aging of the general population, the increased incidence of pharyngolaryngeal operations and the prolonged survival of neurological patients. A good understanding of the nervous control and anatomical structures as well as the physiology of deglutition is therefore important to decide which investigations and treatments should be proposed.

[Amnesic syndrome caused by infarction in the area of the left anterior choroidal artery].

A case of infarction in the left anterior choroidal artery territory presenting as a regressive amnestic syndrome, associated with the usual syndrome, is reported. This amnesia had the same characteristics as that found in the left posterior cerebral artery territory infarction. The anterior choroidal artery supplies the medial part of the temporal lobe, the amygdaloid nucleus, part of the hippocampus, uncal gyrus, and the mamillary body.