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Biomedical subjects

H Petit

Publications and source records attributed to H Petit.

At least 307 records · Page 17Linked to original sources
PubMedDate not supplied

Explicit memory in frontotemporal dementia: the role of medial temporal atrophy.

In our memory clinic experience, memory impairment differs widely in patients with frontotemporal dementia (FTD). We searched for a correlation between explicit memory disturbance assessed with the Grober and Buschke test and medial temporal atrophy on CT scan in 22 consecutive patients with FTD. Five of the 22 patients had a medial temporal lobe (MTL) atrophy. There was no significant difference between the two groups for the demographic characteristics. Free recall, cued recall and the learning curve were significantly better in patients without MTL atrophy. The patients with MTL atrophy made more intrusions. We found a positive correlation between total recall and cued recall and the mean of medial temporal lobe measurement. These results are in agreement with the role of the hippocampal formation in the memory process. In our group, the ratio of patients with MTL atrophy is similar to the ratio of Pick's disease in frontotemporal dementia. In histological series more severe hippocampal atrophy are reported in Pick's disease. Therefore MTL atrophy on CT scan could be a marker of Pick's disease in FTD.

Aged↗
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The effects of donepezil in Alzheimer's disease - results from a multinational trial.

Donepezil has been shown to be well tolerated and to improve cognition and global function in patients with mild to moderately severe Alzheimer's disease (AD). The current trial was undertaken to investigate further the efficacy and safety of donepezil, in a multinational setting, in patients with mild to moderately severe AD. This 30-week, placebo-controlled, parallel-group study consisted of a 24-week, double-blind treatment phase followed by a 6-week, single-blind, placebo washout. Eight hundred and eighteen patients with mild to moderately severe AD were randomly allocated to treatment with single, daily doses of 5 or 10 mg donepezil, or placebo. The two primary efficacy measures were: a cognitive performance test, the Alzheimer's Disease Assessment Scale-cognitive subscale (ADAS-cog) and a global evaluation, the Clinician's Interview-Based Impression of Change with caregiver input (CIBIC plus). Secondary outcome measures included the Sum of the Boxes of the Clinical Dementia Rating Scale (CDR-SB), a modified Interview for Deterioration in Daily living activities in Dementia (IDDD) and a patient rated quality of life assessment. Statistically significant improvements in cognitive and global function were observed, as evaluated by ADAS-cog and CIBIC plus, respectively, in both the 5 and 10 mg/day donepezil groups, compared with placebo. Treatment-associated changes were also observed in functional skills, as shown by improved scores on the CDR-SB and the complex-tasks component of the IDDD. A dose-response effect was evident, with the 10 mg/day donepezil group demonstrating greater benefits in all outcome measures than the 5 mg/day group. Donepezil was well tolerated by this patient population and did not produce any clinically significant laboratory test abnormalities. The results of this study confirm that donepezil is effective and well tolerated in treating the symptoms of mild to moderately severe AD.

Aged↗
PubMedDate not supplied

The use of SPECT in a multidisciplinary memory clinic.

We tested the interobserver reliability of visual rating of HMPAO-SPECT imaging in 271 outpatients referred to a memory clinic, and followed over 1 year. The clinical diagnoses were Alzheimer's disease (n = 156), frontotemporal dementia (n = 47); vascular dementia (n = 21), senile dementia of Lewy body type (n = 12), anxiety/depressive disorders (n = 14) and miscellaneous memory disorders (n = 21). The interobserver agreement was good (k = 0.68). However, the heterogeneity of the patterns-independent from demographic data, age at onset and duration of the disease- and their lack of sensibility and specificity limited the contribution of SPECT for diagnostic purposes in routine practice.

Aged↗
PubMedDate not supplied

[A new approach to arterial rigidity: ultrasonic tissue mode imaging].

Vascular stiffness is a major contributory factor of cardiovascular morbidity and mortality. Tissue Doppler imaging (TDI) could make it possible to evaluate vascular rigidity in a site by the measurement of the arterial wall velocity. The objective of this work is to validate the use of tissue Doppler imaging in the assessment of carotid rigidity. The following parameters were measured with TDI (ATL HDI 5000 and software HDI Lab): maximum velocity and mean acceleration of parietal motion (VMax and AccMax). These measurements were corrected for the arterial diameter and pulse pressure (VMax cor and AccMax cor). These data have been compared to the calculated parameters of elasticity from a mode M echography. Thirty-one subjects aged of 26 to 77 years (41.6 +/- 10.6 years, m +/- ESM), without atheromatous plaque or high blood pressure, have been included. The VMax is correlated very significantly at the parietal velocity calculated with mode M echography (r = 0.77; p = 0.00002). The VMax cor is correlated significantly with the parameters of stiffness following: distensibility coefficient, compliance coefficient, pulse wave velocity, elasticity modulus of Young, coefficient beta. [table: see text] Tissue Doppler imaging allows an easy evaluation of the carotid stiffness correlated with the parameters of elasticity. Therefore it constitutes a method of evaluation of the cardiovascular risk. Further longitudinal studies will be able to assess the involvement of the carotid stiffness as causal agent of the cardiovascular risk.

Adult↗
PubMedDate not supplied

[Long-term selegiline tolerance in the treatment of Parkinson's disease].

Tolerability is one of the main problems of the long-term use of antiparkinsonian drugs, especially in the advanced stages of Parkinson's disease. Since 1988, we have performed a prospective study to assess the clinical and therapeutic factors which may influence the tolerability of a new antiparkinsonian drug, selegiline. 168 patients, with a mean age of 68, were treated with selegiline in combination with L-Dopa or with L-Dopa and a dopamine agonist (bromocriptine, lisuride or piribedil). After an average of 19 months, 23 adverse effects (13.7%) were noted during the first three months of treatment with selegiline. Discontinuation was required in only 10 cases (5.9%) with 9 out of 10 for a psychotic episode. Neither age, nor the stage of the disease, nor the dose of levodopa in combination with selegiline or the presence of mental disturbances seemed to be predicting factors for appearance of a psychic episode. If selegiline with levodopa or with bromocriptine and levodopa appeared to be safe antiparkinsonian combinations, significant psychic side effects occurred with piribedil in combinations with selegiline and levodopa. A possible explanation was that selegiline potentiates piribedil side-effects.

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PubMedDate not supplied

[Randomized study during a year of early combination of L-dopa/lisuride in Parkinson disease].

The tolerance and efficacy of dopatherapy associated to lisuride or placebo were compared in 74 de novo patients with Parkinson's disease in a prospective randomized trial. Only non depressed and non demented patients, previously treated with low doses of levodopa during less than one year, were included in this study. Mean age was 59 (range 36-68). After 12 months, the mean dosage of levodopa was higher in the placebo group than in the lisuride group (318 +/- 121 and 274 +/- 74 mg daily respectively). We observed a different decrease in the Unified Parkinson's Disease Rating Scale with better scores in the lisuride group than in the placebo group, especially for the motor items (p less than 0.001) and the daily living (p less than 0.0001). The tolerance was similar in the two groups. This trial will be continued in open conditions over a period of 4 years to appreciate the incidence of motor fluctuations in the two groups.

Double-Blind Method↗
PubMedDate not supplied

Dystrophic neuropeptidergic neurites in senile plaques of Alzheimer's disease precede formation of paired helical filaments.

The relationship between peptidergic neurites and paired helical filaments (PHF)-positive neurites in Alzheimer's disease (AD) senile plaques (SP) was studied using combined fluorescence and bright field optics. Cryostat sections of AD hippocampi were first stained by thioflavine-S and immunolabeled with antisera raised against different neuropeptides: somatostatin 28(1-12) (som 28(1-12)), somatostatin 14 (som 14), neuropeptide Y (NPY), cholecystokinin (CCK) and substance P (sP). Secondly, using the elution-restaining procedure, sections were immunolabeled with anti-tau/PHF. In immature SP, clusters of abnormal, swollen neurites were found. The dystrophic, strongly peptidic-positive neurites contained less PHF than the poorly positive ones. Cell bodies, exhibiting a peptidic content, could be found within SP without any alteration. These results suggest the following sequence of events: an extracellular poisoning mechanism, perhaps the amyloid substance, first changes the structure of presynaptic endings and causes the formation of ballooning dystrophic neurites filled with their normal peptidic content. Subsequently, intracellular degradation occurs with formation of the PHF. Then the other structures such as dendrites and perikarya are damaged by the same mechanism. Therefore this phenomenon seems to precede any formation of PHF in SP.

Alzheimer Disease↗
PubMedDate not supplied

Severe hypoglycorrhachia after subarachnoid hemorrhage. Two cases with spontaneous recovery in adults.

We report two patients with severe hypoglycorrhachia after a subarachnoid hemorrhage. They had no obvious meningeal infection, and they spontaneously recovered within a few weeks. Such cases have previously been reported in neonates, but exceptionally in adults. Contrary to detailed cases from the literature, our patients recovered without antibiotics, and hypoglycorrhachia was very severe.

Aged↗
PubMedDate not supplied

[Amnesia in thalamic infarction].

Restricted thalamic infarctions are in man a useful model for investigating the consequences of limited diencephalic lesions on memory and verbal or visual learning. Two new cases of amnesia with thalamo-sub-thalamic infarctions are presented, with a general review of the problem. The gathering of the different cases according to the vascular thalamic territories and, as a consequence, to nuclear or associative structures concerned, allows a better approach of the relations between amnesia and infarctions. Uni or bilateral anterior lesions are the cause of more important and pure memory deficits, posterior infarctions are more often associated to language involvement or spatial cognitive problems which interfere with memorizing.

Adult↗
PubMedDate not supplied

[Late posttraumatic syringomyelic syndromes. Pathogenetic theories apropos of 3 cases].

Three patients with a post-traumatic spinal cord cavity are described: clinical signs are identical to those of syringomyelia, but pain is more frequent. Diagnosis is made easier by magnetic resonance imaging (MRI) and a syringoperitoneal shunt is proposed for treatment. Nevertheless, if results are good, they seem worse than in idiopathic syringomyelia. The main pathogenic theories are discussed: the rupture and coalescence of microcysts developed at a distance of 1 or 2 mm from the transected spinal cord, subsequently leads to syrinx formation; haemorrhagic or ischemic post-traumatic areas could also lead to syrinx formation. Hydrodynamic factors could be expected and make the pathogenesis not far from syringomyelic one.

Adult↗