References of "PEPIN, Jean-Louis"
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See detailFrontal and posterior cingulate metabolic impairment in the behavioural variant of frontotemporal dementia with impaired autonoetic consciousness
Bastin, Christine ULg; Feyers, Dorothée ULg; Souchay, Céline et al

in Human Brain Mapping (2012), 33

Although memory dysfunction is not a prominent feature of the behavioural variant of frontotemporal dementia (bv-FTD), there is evidence of specific deficits of episodic memory in these patients. They ... [more ▼]

Although memory dysfunction is not a prominent feature of the behavioural variant of frontotemporal dementia (bv-FTD), there is evidence of specific deficits of episodic memory in these patients. They also have problems monitoring their memory performance. The objective of the present study was to explore the ability to consciously retrieve own encoding of the context of events (autonoetic consciousness) and the ability to monitor memory performance using feeling-of-knowing (FOK) in bv-FTD. Analyses of the patients’ cerebral metabolism (FDG-PET) allowed an examination of whether impaired episodic memory in bv-FTD is associated with the frontal dysfunction characteristic of the pathology or a dysfunction of memory-specific regions pertaining to Papez’s circuit. Data were obtained from 8 bv-FTD patients and 26 healthy controls. Autonoetic consciousness was evaluated by Remember responses during the recognition memory phase of the FOK experiment. As a group, bv-FTD patients demonstrated a decline in autonoetic consciousness and FOK accuracy at the chance level. While memory monitoring was impaired in most (7) patients, 4 bv-FTD participants had individual impairment of autonoetic consciousness. They specifically showed reduced metabolism in the anterior medial prefrontal cortex, the left dorsolateral prefrontal cortex (near the superior frontal sulcus), parietal regions and the posterior cingulate cortex. These findings were tentatively interpreted by considering the role of the metabolically impaired brain regions in self-referential processes, suggesting that the bv-FTD patients’ problem consciously retrieving episodic memories may stem at least partly from deficient access to and maintenance/use of information about the self. [less ▲]

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See detailIntravenous immunoglobulins in paraneoplastic brainstem encephalitis with anti-Ri antibodies
Fumal, Arnaud ULg; Jobe, Jérôme ULg; PEPIN, Jean-Louis ULg et al

in Journal of Neurology (2006), 253(10), 1360-1361

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See detailMethodological Issues in a Cost-of-Dementia Study in Belgium: The National Dementia Economic Study (Nades)
Kurz, Xavier; Broers, Mattie; Scuvée-Moreau, Jacqueline ULg et al

in Acta Neurologica Belgica (1999), 99(3), 167-75

The NAtional Dementia Economic Study (NADES) is an on-going prospective, one-year cohort study developed in Belgium to assess the socio-economic consequences of dementia in a group of patients and their ... [more ▼]

The NAtional Dementia Economic Study (NADES) is an on-going prospective, one-year cohort study developed in Belgium to assess the socio-economic consequences of dementia in a group of patients and their caregivers (n = 400). Comparison is made with a group of subjects with cognitive impairment and no dementia (n = 100) and a group of subjects without any cognitive impairment (n = 100). Recruitment of subjects is based on screening of warning signs of dementia by general practitioners, followed by a Cambridge Mental Disorders of the Elderly Examination (CAMDEX) performed at home. This paper presents an overview of the study protocol and the rationale for basic design options, such as the choice of study population, screening strategy, and methods used for the case validation. It also presents preliminary results on the prevalence of dementia in general practice, the sensitivity and specificity of the warning signs as a screening test of dementia, and the validity of a computerised case ascertainment algorithm based on DSM-III-R criteria. [less ▲]

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See detailLes manifestations neurologiques de l'infection a Borrelia burgdorferi (maladie de Lyme).
PEPIN, Jean-Louis ULg; Bastings, Eric; Lenaerts, Marc ULg et al

in Revue Médicale de Liège (1994), 49(11), 603-10

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See detailThe Audiospinal Reaction in Parkinsonian Patients Reflects Functional Changes in Reticular Nuclei
Delwaide, Paul ULg; PEPIN, Jean-Louis ULg; Maertens De Noordhout, Alain ULg

in Annals of Neurology (1993), 33(1), 63-9

Audiospinal facilitation using the soleus H-reflex as a test was compared in 16 control subjects and 23 parkinsonian patients. In the patients, facilitation was significantly reduced during the 75 to 150 ... [more ▼]

Audiospinal facilitation using the soleus H-reflex as a test was compared in 16 control subjects and 23 parkinsonian patients. In the patients, facilitation was significantly reduced during the 75 to 150 msec after the conditioning stimulation. This reduction was seen bilaterally even in patients with a hemisyndrome. It was corrected by L-dopa but not by anticholinergic agents. Facilitation at the 75-msec delay showed an inverse linear correlation with the bradykinesia intensity (r = -0.7, p < 0.01). The results argue in favor of a reduced excitability of the nucleus reticularis pontis caudalis from which a reticulospinal tract emanates as effector of the audiospinal facilitation. This would represent another example of dysfunction of reticular nuclei in Parkinson's disease. [less ▲]

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See detailContribution of reticular nuclei in the pathophysiology of parkinsonian rigidity
Delwaide, Paul ULg; PEPIN, Jean-Louis ULg; MAERTENS DE NOORDHOUT, Alain ULg

in Narabayashi, H.; Nagatsu, T.; yanagisawa, N. (Eds.) et al Advances in Neurology - Vol 60 (1993)

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See detailPercutaneous Magnetic Stimulation of the Motor Cortex in Migraine
MAERTENS DE NOORDHOUT, Alain ULg; Pepin, Jean-Louis ULg; Schoenen, Jean ULg et al

in Electroencephalography and Clinical Neurophysiology (1992), 85(2), 110-5

We have used transcranial magnetic stimulation of the motor cortex interictally in 12 patients with unilateral classic migraine with sensorimotor auras and 10 patients with common migraine and unilateral ... [more ▼]

We have used transcranial magnetic stimulation of the motor cortex interictally in 12 patients with unilateral classic migraine with sensorimotor auras and 10 patients with common migraine and unilateral headache. In classic migraine, the threshold of activation of the FDI muscle by the cortical stimulus was significantly increased on the side of the auras, when compared to the unaffected side (P less than 0.01) and to normal subjects (P less than 0.01). The amplitude of EMG responses was also reduced in FDI on the affected side when compared to normals (P less than 0.02). Responses obtained in common migraine patients were normal on both sides. We suggest that some permanent subclinical dysfunction of the motor cortex might play a role in the pathogenesis of attacks of classic migraine with sensorimotor auras. [less ▲]

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See detailFacilitation of Responses to Motor Cortex Stimulation: Effects of Isometric Voluntary Contraction
Maertens De Noordhout, Alain ULg; PEPIN, Jean-Louis ULg; GERARD, Pascale ULg et al

in Annals of Neurology (1992), 32(3), 365-70

In 7 normal subjects we compared the facilitatory effect of isometric contraction of the tibialis anterior on the size of electromyographic responses evoked in this muscle by electric stimuli applied over ... [more ▼]

In 7 normal subjects we compared the facilitatory effect of isometric contraction of the tibialis anterior on the size of electromyographic responses evoked in this muscle by electric stimuli applied over the cervical column and by electric and magnetic percutaneous stimulation of the motor cortex. No significant difference was found between the degrees of facilitation of the responses to any of the stimuli. Using collision techniques, we also showed that the pyramidal fibers activated by spinal and cortical stimuli are the same. Facilitation induced by isometric contraction (20% maximum) was of similar or greater magnitude than that found with constant vibration of the tendon of the target muscle. In cases where vibration and contraction had equal facilitatory effects, there was no further facilitation of the responses when both conditions were applied together. These findings indicate that the facilitatory effect of isometric contraction of the target muscle essentially originates at a spinal level rather than in the motor cortex. [less ▲]

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See detailMagnetic Stimulation of the Motor Cortex in Cervical Spondylosis
Maertens De Noordhout, Alain ULg; Remacle, J. M.; PEPIN, Jean-Louis ULg et al

in Neurology (1991), 41(1), 75-80

We report a new technique of transcranial magnetic stimulation of the motor cortex to measure conduction within central motor pathways of 67 patients with cervical spondylosis or disk herniation. There ... [more ▼]

We report a new technique of transcranial magnetic stimulation of the motor cortex to measure conduction within central motor pathways of 67 patients with cervical spondylosis or disk herniation. There were upper motor neuron signs in 34 patients (51%) and x-ray evidence of cervical cord compression in 44 (66%). Muscle action potentials (MAPs) to cortical stimulation were abnormal in 84% of patients with, and 22% of those without, radiologic signs of cervical cord compression. Median nerve somatosensory evoked potentials were altered in only 25% of patients. The frequency of MAP alterations correlated with upper motor neuron signs. In 5 (11%) of the 44 patients with x-ray evidence of cervical cord compression, subclinical cord compression was disclosed by cortical stimulation. In 10 patients restudied 3 months after surgical decompression, normalization of central motor conduction time did not occur, indicating permanent damage to the cervical cord. [less ▲]

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See detailShort-latency autogenic inhibition in patients with Parkinsonian rigidity.
Delwaide, Paul ULg; PEPIN, Jean-Louis ULg; MAERTENS DE NOORDHOUT, Alain ULg

in Annals of Neurology (1991), 30(1), 83-9

The spinal Ib interneuron efficacy has been compared in 11 control subjects and 19 patients with parkinsonian rigidity. In normal subjects, gastrocnemius medialis nerve stimulation induces an inhibition ... [more ▼]

The spinal Ib interneuron efficacy has been compared in 11 control subjects and 19 patients with parkinsonian rigidity. In normal subjects, gastrocnemius medialis nerve stimulation induces an inhibition of the soleus H reflex for 3 to 8 msec with a peak at 5 msec of 83.72 +/- 7.28% of the control value of H reflex. In parkinsonian patients, inhibition is reduced or even replaced by facilitation, which also peaks at 5 msec. The departures from normal values correlate with rigidity intensity assessed by the Webster scale. Increase in rigidity is associated, first, with a reduction of inhibition and, from a score of 2 or more, with facilitation replacing the normal inhibition. In addition to providing an electrophysiological index of rigidity, reduction in autogenic inhibition might be one of the neurophysiological mechanisms underlying rigidity. In association with the known hyperactivity of the Ia inhibitory interneuron in Parkinson's disease, reduction of activity of Ib interneuron could be explained by an increased activity in the reticularis gigantocellularis nucleus; its efferent tracts both inhibit Ib interneurons and activate Ia interneurons. [less ▲]

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See detailLa rigidite parkinsonienne: aspects cliniques et physiopathologiques.
Delwaide, Paul ULg; PEPIN, Jean-Louis ULg; MAERTENS DE NOORDHOUT, Alain ULg

in Revue Neurologique (1990), 146(10), 548-54

Neurophysiologic mechanisms responsible for parkinsonian rigidity are poorly understood. In any case, they have to fit all the clinical data which are first reviewed before discussing 2 theories which are ... [more ▼]

Neurophysiologic mechanisms responsible for parkinsonian rigidity are poorly understood. In any case, they have to fit all the clinical data which are first reviewed before discussing 2 theories which are proposed to interpret rigidity. The first theory postulates that increased resistance to mobilization is due to hyperactivity in a long loop reflex pathway which originates at the neuromuscular spindles and relays in the motor cortex. This theory is based on the largely accepted finding that, in parkinsonian patients, M2 response is increased when a voluntary movement is abruptly stopped. Although popular this hypothesis is far from explaining all the clinical facts, namely that rigidity is equal in extensor and flexor, proximal and distal muscles. Based on a reflex set by primary afferent discharges, it is incompatible with the lack of rigidity reinforcement after faster passive mobilization. The second theory rests on data obtained from electrophysiological studies of some spinal interneurones. Both IA and IB inhibitory interneurones are functionally modified but not in the same direction. While the IA inhibitory interneurone is facilitated, the IB inhibitory interneurone is less active. Disappearance of autogenic inhibition can explain rigidity at rest and the tonic stretch reflex. In addition, interneurones intervening in the flexor reflex disclose a modified excitability. It is possible to interpret these facts by postulating an abnormal influence transmitted through descending reticulospinal pathways. This abnormal influence would result from modified activation of reticular nuclei by afferents projecting from the basal ganglia. Such a hypothesis is open to experimental testing through the startle reaction. The latter facilitates the H reflex by the reticulospinal pathways, the influence of cortex--if any--being negligible.(ABSTRACT TRUNCATED AT 250 WORDS) [less ▲]

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See detailReinforcement of reciprocal inhibition by contralateral movements in man
Delwaide, Paul ULg; Sabatino, Mike; PEPIN, Jean-Louis ULg et al

in Experimental Neurology (1988), 99

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