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Biomedical subjects

I Rouleau

Publications and source records attributed to I Rouleau.

27 records · Page 2Linked to original sources
PubMed1991

Obstructive sleep apnea syndrome: pathogenesis of neuropsychological deficits.

Neuropsychological deficits have been documented in patients with obstructive sleep apnea syndrome (OSAS). Both nocturnal hypoxemia and impairement of daytime vigilance have been suggested as the pathogenesis of these deficits, yet it remains difficult to find good correlations between cognitive deficits and either of these physiological parameters. In the present study, 10 normal controls were compared to 10 moderately and 10 severely apneic patients, all recorded in a sleep laboratory for two consecutive nights, with a vigilance and neuropsychological assessment made during the intervening day. Relative to the controls, moderate and severe OSAS showed differences in many cognitive functions, although the severely affected showed the greater differences. Moreover, severe apneics were also worse than moderate apneics on tests that were found to be normal in the latter group. This suggests a discontinuity in the appearance of neuropsychological deficits as OSAS progresses. Further analyses revealed that reductions in general intellectual measures, as well as in executive and psychomotor tasks were all attributable to the severity of hypoxemia, while other attention and memory deficits were related to vigiance impairment. Therefore, both vigilance impairment and nocturnal hypoxemia may differentially contribute to the cognitive dysfunctions found in OSAS.

Adult↗
PubMed1990

Interhemispheric EEG coherence before and after partial callosotomy.

Measures of interhemispheric EEG coherence during REM and NREM sleep reflect the functional connectivity of the right and left hemispheres mediated by the corpus callosum. Surface recordings of interhemispheric coherence in two patients reflected fairly accurately the degree of anatomical section produced by partial callosotomy. With further development, EEG coherence may prove useful as a noninvasive method for assessing interhemispheric integration under different physiological and experimental conditions.

Adult↗
PubMed1989

Short-term and long-term memory deficit following intracarotid Amytal injection: further support for the memory consolidation hypothesis.

To test the three main hypotheses of the human amnesic syndrome (encoding, consolidation, retrieval), we designed an original protocol for memory assessment under Amytal that included, in addition to a retrograde memory measure, both short-term and long-term anterograde memory measures. Twenty epileptic patients with SEEG-confirmed unilateral temporal lobe foci were given right and left injections on successive days. Only the long-term memory measure for material presented under Amytal was significantly related to the presence of a temporal contralateral epileptogenic focus, even if it was assessed when the hemisphere had completely recovered from the effect of Amytal. Short-term memory deficits were observed equally often after injections ipsilateral and contralateral to the epileptogenic focus, and no retrograde amnesia was observed. These results are consistent with the consolidation hypothesis.

Adolescent↗
PubMed1987

Nocturnal sleep recording in partial epilepsy: a study with depth electrodes.

It has been known for centuries that sleep and epilepsy have strong reciprocal influences. This is true for all kinds of epilepsies, although the nature of this influence varies quite markedly for each type. This extensive literature cannot be reviewed here, but some recent applications of these early studies will be given.

Electroencephalography↗
PubMed1985

Hypnogenic paroxysmal dystonia: epilepsy or sleep disorder? A case report.

A patient was studied who every night experienced several attacks characterized by loud screaming, violent movements of limbs and trunk, and a tonic phase. No epileptiform activity was noted preceding or following these attacks. Prolonged EEG and videotape recordings before and after sleep deprivation, along with neuropsychological and pharmacological data, support the hypothesis of a seizure disorder involving the left temporal region. Nocturnal attacks completely disappeared with carbamazepine. This therapeutic effect was still present after six months of treatment. Sleep organization was also greatly influenced by this medication. The most striking change was the marked and sustained increase of stages 3 and 4 NREM sleep after treatment.

Adult↗
PubMedDate not supplied

Pattern of intrusions in verbal recall: comparison of Alzheimer's disease, Parkinson's disease, and frontal lobe dementia.

Although some researchers have suggested that intrusions in word list learning are more frequent in Alzheimer's disease, recent studies have shown that this might not be true. In fact, intrusions are common in many neurological degenerative diseases. The goal of the present study was to examine the types of intrusions made by three groups of patients, namely patients with Parkinson's disease (PD), Alzheimer's disease (AD), and dementia with prominent frontal lobe semiology (FD). Although PD patients learned more words (trials 1 to 5 on the RAVLT) than the two other groups, there was no significant difference in the total number of intrusions. However, significant differences between groups were observed for nonrelated intrusions, the proportion of PD patients (15.4%) being lower than the proportion of AD (45.5%) and FD (45.8%) patients with this type of intrusions. No other type of intrusions (same category, recurring, phonemic) significantly differentiated between the three groups. The proactive interference effect (PI), measured as the difference between first recall of list A and list B recall, was stronger in PD than in the two other groups, reflecting the strong positive correlation between total number of words recalled on the RAVLT and severity of the PI effect. Prior list intrusions (intrusions from list A while recalling list B items) were significantly more pronounced in FD than in the two other groups. Finally, free associations (series of intrusions related to one another but not to the target items) were observed almost exclusively in FD patients. These findings illustrate some qualitative differences between various neurological degenerative diseases. They also stress the marked similarities between AD and FD with regards to verbal learning.

Aged↗
PubMedDate not supplied

Prevalence, and intellectual outcome of unilateral focal cortical brain damage as a function of age, sex and aetiology.

Neurologists and neuropsychologists are aware that aging men are more at risk than women for brain damage, principally because of the well known male-predominant risk for cardiovascular disease and related cerebrovascular accidents. However, a disproportion in prevalence of brain damage between the sexes in childhood may be less suspected. Furthermore, sex-specific risk for other aetiologies of brain damage may be little known, whether in the pediatric or adult populations. Proposals of a sex difference in cognitive recovery from brain damage have also been controversial. Six hundred and thirty five "consecutive" cases with cortical focal lesions including cases of all ages and both sexes were reviewed. Aetiology of the lesion was determined for each case as was postlesion IQ. Risk was highly male prevalent in all age groups, with a predominance of cardiovascular aetiology explaining much of the adult male prevalence. However, several other aetiological categories were significantly male prevalent in juveniles (mitotic, traumatic, dysplasic) and adults (mitotic, traumatic). There was no sex difference in outcome (i.e., postlesion IQ) of these cortical brain lesions for the cohort as a whole, after statistical removal of the influence of lesion extent, aetiology and presence of epilepsy. Mechanisms potentially responsible for sex differences in prevalence, aetiology of brain damage, and recovery, are reviewed and discussed.

Adolescent↗