Biomedical subjects

Catherine Bourdet

Publications and source records attributed to Catherine Bourdet.

3 recordsLinked to original sources

PubMed2006

Effect of fetal neural transplants in patients with Huntington's disease 6 years after surgery: a long-term follow-up study.

BACKGROUND: Although we have shown in three out of five patients with Huntington's disease that motor and cognitive improvements 2 years after intracerebral fetal neural grafts are correlated with recovery of brain metabolic activity in grafted striatal areas and connected regions of the cerebral cortex, neural grafts are not known to have protective effects on the host brain per se. We undertook long-term follow-up of previously reported patients with the disease to ascertain the nature and extent of any secondary decline after grafting. METHODS: Five patients with Huntington's disease from our pilot study were assessed annually with the unified Huntington's disease rating scale, neuropsychological tests, and MRI, for up to 6 years after neural grafting. Resting cerebral activity was recorded at 2 and 6 years. FINDINGS: Clinical improvement plateaued after 2 years and then faded off variably 4-6 years after surgery. Dystonia deteriorated consistently, whereas chorea did not. Cognitive performance remained stable on non-timed tests, whereas progression of motor disability was shown by deterioration on timed tests. Hypometabolism also affected the brain heterogeneously, sparing the benefits in the frontal cortex and at the precise location of the grafts, but showing a progressive deterioration in other areas. Two patients who had no benefit from grafting at 2 years continued to decline in the same way as non-grafted patients. INTERPRETATION: Neuronal transplantation in Huntington's disease provides a period of several years of improvement and stability, but not a permanent cure for the disease. Improvement of the surgical procedure and in patient selection could improve the therapeutic value, but neuroprotective treatment seems to be unavoidable in the disease.

Adult↗

PubMed2003

Auditory temporal processing in schizophrenia: high level rather than low level deficits?

INTRODUCTION: Patients with schizophrenia demonstrate a wide range of information processing deficits. Most recent studies argue in favour of high level deficits, including attention and context processing, whereas fewer studies have demonstrated deficits at earlier stages of processing, such as perceptual discrimination and organisation. This is the first study to investigate both high and low level processing, within a single paradigm, in the case of auditory temporal processing in schizophrenia. METHODS: Patients with schizophrenia were compared to controls on a series of tasks involving three auditory temporal processes varying from low to higher level: (1) segregation of a complex sequence into component auditory streams; (2) detection of local temporal irregularities within a stream; (3) attentional focusing on one stream by the use of a cue preceding the complex sequence. RESULTS: The lowest level of processing examined here--stream segregation--appeared to function equally well in patients as in controls. However, the higher level processes--irregularity detection and attentional focus--functioned in both groups, but less efficiently in patients with schizophrenia. CONCLUSIONS: Results demonstrate abnormal auditory temporal processing in schizophrenia. Abnormal performances only in Processes 2 and 3 support and hypothesis of higher level rather than lower level processing deficits in schizophrenia.

Journal Article↗

PubMed2002

Clinical relevance of electrophysiological tests in the assessment of patients with Huntington's disease.

Assessment programs recently designed to follow-up patients with Huntington's disease (HD) in therapeutic trials have not included electrophysiological testing in the list of mandatory examinations. This omission is likely due to the current lack of data establishing a clear correlation between the electrophysiological results and those of clinical assessment. We address this issue in a cohort of 36 patients at relatively early stages of the disease (I and II). Electrophysiological studies comprised the recording of palmar sympathetic skin responses (SSRs), blink reflexes (BRs), thenar long latency reflexes (LLRs), cortical somatosensory evoked potentials (SEPs), and electromyographic silent periods evoked by transcranial magnetic stimulation (SPs). Results were analyzed with reference to disease duration and staging and to specific cognitive, psychiatric, and motor alteration. SEPs were the most and very sensitive markers, because they were abnormal in 94% of patients. Except for LLRs, alteration of electrophysiological results increased in parallel to the evolution of the disease. Except for LLRs and SSR latency, electrophysiological results correlated with those of specific clinical examinations. In particular, an increased BR latency or a reduced amplitude of the N20 component of SEPs correlated with the extent of bradykinesia, whereas a reduced amplitude of SSRs or of the N30 component of SEPs correlated with hyperkinesia. Overall, electrophysiological tests, in particular SEPs and BRs, appeared sensitive and interesting in the follow-up of HD patients and correlated with various clinical parameters, suggesting that these easy to perform and noninvasive repeatable examinations could be added fruitfully to the assessment programs for HD.

Adult↗