[Lyrical and musical auditive mental imagery in functional MRI]. / Imagerie magerie mentale auditive lyrique et musicale en IRM fontionnelle d'activation.

PURPOSE: to explore with functional MRI cerebral areas involved in musical and lyrical sounds signal processing with the mental imagery method. MATERIAL: and METHODS: nine volunteers (mean age: 27 years old) underwent functional MRI with BOLD contrast at 1.5 T. Box-car paradigms of partial recollections of musical or lyrical memories tasks were performed. Statistical correlations mappings were calculated and superimposed on previously realigned anatomical reference imaging to observe activated cerebral areas. RESULTS: all except one subjects had activation areas in primary and secondary auditive cortices in the temporal Heschl gyrus and the Planum Temporale, unilaterally (n=2) or bilaterally (n=6) during both mental tasks. Contralateral activation improvement was observed in 4 cases when the lyrical tasks were performed. Temporal and insular regions involved in language processing were observed in eight of nine subjects. CONCLUSION: auditive mental imagery can show in functional MRI cerebral areas involved in auditive functions and some of the areas involved in language processing.

Arteriovenous malformations of the dental arcades. The place of endovascular therapy: results in 12 cases are presented.

Twelve arteriovenous malformations of the dental arcades (AVMDAs) (seven mandibular and five maxillary) were seen in our institution between 1977 and 1997. All these lesions consisted of true arteriovenous shunts (of either nidus or fistulous type) involving the bone, with or without soft tissue extension. Haemorrhage was present in eight patients (67%); either torrential, necessitating emergency embolization, or recurrent and progressive. Teeth instability was detected in all patients and was the origin of the bleeding. All lesions were embolized. Lesions in nine patients were embolized with Polyvinyl Alcohol Particles (PVA): this helped to stabilize the situation but could not avoid recurrences in all patients, necessitating complementary embolizations and or surgery. The use of acrylic glue (N-Butyl-Cyano-Acrylate [NBCA] Histoacryl) as the embolic agent has changed the results obtained tremendously. Eight patients have been treated with NBCA (five as complementary therapy to PVA during later sessions and three at the first attempt); injection either via the transarterial route or direct transcutaneous puncture (four patients) achieved a cure in four of these lesions (34%) with stability at long-term follow-up of all the other AVMs. Embolization with glue represents the therapy of choice in these sometimes life-threatening lesions, achieving a cure if directed towards the osseous venous lakes. Surgery, often leading to facial mutilation and necessitating massive reconstruction should be avoided nowadays, at least as the initial therapy.