[Contracts including performance and management of uncertainty]. / Contrats de performance et management de l'incertitude.

Since many decades in France, the most important part of ambulatory health care expenditure is represented by drug consumption. By the fact, French patient is indeed the greatest world consumer of pharmaceuticals treatments. Therefore, the regulation authorities by successive strategies, attempt to limit or even restrict market access for new drugs in the health care sector secured by public social insurance coverage. Common objectives are to assess the reimbursement to scientific studies and to fix the price of therapeutics at an acceptable level for both industries and government. New trends try then to determine recently the drug price in a dual approach, as a component of global and effective contract, including performance and outcome. The first diffusion authorization is diffusion concerned, but this concept takes into account the eventual success of new produces in long-term survey. Signed for a fixed period as reciprocal partnership between regulation authorities and pharmaceutics industries, the contract integrates two dimensions of incertitude. The first one is represented by the strategy of new treatments development according to efficacy and adapted price, and the second one is linked to the result of diffusion and determines adapted rules if eventual non-respects of the previous engagement are registered. This paper discusses problems related to this new dimension of incertitude affected by conditional drug prices in market access strategy and the adapted follow-up of new treatment diffusion fixed by "outcome" contract between French regulation administration and pharmaceutics industries in our recent economic context.

Timing and characteristics of perceptual attenuation by transcranial stimulation: a study using magnetic cortical stimulation and somatosensory-evoked potentials.

Transcranial cortical magnetic stimulation (CMS) is a noninvasive, non-noxious procedure to induce perceptual attenuation when applied concomitant to sensory stimuli. To investigate the perceptual timing of simple stimulus features in the somatosensory modality, we applied right hemisphere CMS at different intervals following a stimulus delivered to the left hand. Different intervals between peripheral stimuli and CMS were defined according to the components of the somatosensory-evoked potentials (SEP), previously obtained in response to the same stimulus. Perceptual attenuation was maximal when CMS coincided with the primary cortical response (parietal N20 potential); conversely, perception of stimulus intensity was not modified when CMS was concomitant with the N200 and P300 potentials. Using small CMS intensities, a "perceptual dip" was observed when CMS arrived in coincidence with the N120 potential, a SEP response thought to be originated in part in the second somatic area. Our results support the view that both N200 and P300 are post-perceptual responses. The results also suggest that the cortical processes active during the N20 and N120 potentials may be essential for the conscious perception of somatosensory stimuli delivered to the hand.

[Exploration of intraspinal tumors using evoked motor potentials (EMP): correlations with data of evoked somatosensory potentials]. / Exploration par les potentials évoqués moteurs (PEM) des tumeurs intrarachidiennes: correlations avec les données des potentials évoqués somethésiques (PES).

MEPs to transcutaneous magnetic stimulation have been recorded in 43 patients with an intraspinal tumor documented by MRI. The tumor was extramedullary in 18 patients and intramedullary In 25. MEPs were abnormal in 62.8% of patients. There were no significant differences in the rate of MEP abnormalities according to the lesion site or the histological findings, except for meningiomas which showed abnormal MEPs in all eight patients included in this series. The percentage of patients with abnormal MEPs was 9.3% despite the absence of any clinical symptom of central motor pathway dysfunction. Infraclinical MEPs abnormalities were observed in 24% of explored limbs. Median and tibial nerves somatosensory evoked potentials (SEPs) were recorded in 41 patients and showed abnormalities of central conduction or of segmental spinal responses in 65.9% of the cases. When combining data from MEP and SEPs, abnormalities were observed in 70.7% of patients (29/41). Five patients (12.2%) had abnormal MEPs, but normal SEPs, and four other patients (9.8%) had abnormal SEPs, but normal MEPs. This finding suggests that both MEPs and SEPs should be recorded for presurgical evaluation of-intraspinal tumor.

[Progressive lupus dementia. 2 cases with or without antiphospholipid antibodies]. / Démence lupique progressive. Deux cas avec anticorps antiphospholipides ou non.

Two cases of lupus dementia presented many points of particular interest: 1) the progressive installation of intellectual deterioration, inaugural for the first observation; 2) the diagnostic difficulties of neurolupus with the ARA criteria; 3) the appearance of cerebral magnetic resonance imaging with confluent hypersignals of the periventricular white matter on T2-weighted images; 4) the patholophysiological hypotheses: vascular disease? immunologic disease?; 5) the clinical improvement and SPECT amelioration for the second patient with corticosteroids.

Assessment of motor conduction times using magnetic stimulation of brain, spinal cord and peripheral nerves.

Central conduction times (CCTs) in the motor pathways were assessed in normal subjects using a magnetic stimulus for the recording of cortical and spinal (Cv7 and L4-L5) Motor Evoked Potentials (MEPs) as well as F-waves in upper and lower limbs. M-responses of maximal amplitude could be reliably obtained by using a 4.5 Tesla coil and a stimulus intensity of 85% of the maximal output. It was found that the CCTs derived from the latency difference between cortical and spinal MEPs were, on average, 0.90 ms and 3.15 ms longer, respectively for upper and lower limbs, than those obtained by combining cortical MEPs and F-wave latency measurements. This difference is similar to that reported when electric stimulation is used to elicit F-waves and/or spinal MEPs. It suggests that motor root fibers are depolarized at a distance of 7.8 and 17 cm from the cord by a spinal magnetic stimulus applied respectively at Cv7 and L4-L5 levels. This study shows that magnetic stimulation alone permits to assess CCT in motor pathways with the same reliability as any of the other stimulation modalities hitherto proposed in literature.

Progressive amusia and aprosody.

We report a case of slowly progressive amusia and aprosody in association with orofacial and eyelid apraxias. The patient was independent in daily living activities. Insight, judgment, and behavior were intact. Her language was normal, and she demonstrated no limb, dressing, or constructional apraxia. She had no prosopagnosia, no visuospatial disturbances, and no memory impairment. Imaging studies (computed tomography, magnetic resonance imaging, single photon emission computed tomography) indicated a selective disorder of the right frontal and temporal regions. Review of the literature shows an increasing number of reports of this degenerative syndrome affecting the left dominant hemisphere and language areas, whereas cases of the syndrome affecting the right hemisphere are rare. To our knowledge, this is the first case in which aprosody and amusia were associated with a focal cortical degeneration.

[Unilateral scapulohumeral amyotrophy. Contribution of imaging]. / Amyotrophie scapulo-humérale unilatérale. Apport de l'imagerie.

A case of right scapulohumeral muscular atrophy stable after a 6 month progressive course is reported. Cervical metrizamide CT and MRI showed a flattened right cervical spinal cord regarded as a segmental atrophy. The case could belong to the Kaeser type of sporadic chronic spinal amyotrophy, or perhaps corresponds to a benign focal amyotrophy.