References of "Maertens De Noordhout, Alain"
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See detailIntraoperative Localisation of the Primary Motor Cortex Using Single Electrical Stimuli
Maertens De Noordhout, Alain ULg; Born, J. D.; Hans, Pol ULg et al

in Journal of Neurology, Neurosurgery & Psychiatry (1996), 60(4), 442-4

A new method of intraoperative localisation of the primary motor cortex is described, based on the application of single anodal electric pulses to the brain surface. Patients were anaesthetised with ... [more ▼]

A new method of intraoperative localisation of the primary motor cortex is described, based on the application of single anodal electric pulses to the brain surface. Patients were anaesthetised with propofol infusion, and neuromuscular blockade was temporarily alleviated to allow recording of surface EMG responses (CMAPs) to the stimuli. Primary motor areas could be localised in 18/19 patients studied. In the other patient, no responses were elicited, as the operative field was posterior to the motor cortex. When compared with MEPs elicited in awake patients by magnetic stimuli, responses to intraoperative anodal stimulation were of small amplitude (usually less than 10% of MEPs) and their latency was some 1 to 2 ms longer. One month after the operation, only 1/19 patients was left with a slight muscle weakness, although seven showed preoperative motor deficit. The procedure proved easy and fast, needing no preliminary surgery or time consuming preparation. It did not induce any detectable side effects. [less ▲]

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See detailFrom Basal Ganglia to Motoneurons. Probable Involvement of Pathways Relaying in the Medulla
Delwaide, P. J.; Pepin, J. L.; Maertens De Noordhout, Alain ULg

in Battistin, L.; Scarlato, G.; Caraceni, T. (Eds.) et al Advances in Neurology. Volume 69 (1996)

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See detailCan Motor Recovery in Stroke Patients Be Predicted by Early Transcranial Magnetic Stimulation ?
Rapisarda, Giuseppe; Bastings, Eric; MAERTENS DE NOORDHOUT, Alain ULg et al

in Stroke (1996), 27(12), 2191-2196

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See detailClinical neurophysiology and neurotransmitters
MAERTENS DE NOORDHOUT, Alain ULg; Wang, Wei; Schoenen, Jean ULg

in Cephalalgia : An International Journal of Headache (1995), 15(4), 301-9

Clinical neurophysiology allows non-invasive assessment of neurotransmitter function in various regions of the central and peripheral nervous system. In this review, we describe examples of functional ... [more ▼]

Clinical neurophysiology allows non-invasive assessment of neurotransmitter function in various regions of the central and peripheral nervous system. In this review, we describe examples of functional evaluation of neurotransmission at the neuromuscular junction, in some spinal interneurons and intracortical circuits as well as evaluation of pharmacological modulation of some electrophysiological tests. These investigations are carried out to help our understanding of the pathophysiology of brain diseases. Finally, we discuss possible relationships between electrophysiological tests (evoked/event-related potentials and exteroceptive suppression of temporalis muscle activity) and neurotransmitter function in headache. [less ▲]

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See detailControl of drug-resistant epilepsy after head injury with intravenous nimodipine.
HANS, Pol ULg; Triffaux, M.; BONHOMME, Vincent ULg et al

in Acta Anaesthesiologica Belgica (1994), 45(4), 175-8

The present report describes a young child who developed generalized epileptic seizures in the course of severe head injury. The start of epileptic seizures was associated with the occurrence of acute ... [more ▼]

The present report describes a young child who developed generalized epileptic seizures in the course of severe head injury. The start of epileptic seizures was associated with the occurrence of acute hyponatremia and hypoosmolality due to excessive Desmopressine administration. The seizures resistant to conventional therapy resolved completely with intravenous nimodipine infusion. [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 detailHeadache
Schoenen, Jean ULg; MAERTENS DE NOORDHOUT, Alain ULg

in Wall, P. D.; Melzack, R. (Eds.) Textbook of Pain (1994)

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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 detailSuppressions of temporalis muscle activity and their modulations by transcranial magnetic stimulations may reflect direct excitation of the trigeminal nerve or ganglion, and not cortical activation
MAERTENS DE NOORDHOUT, Alain ULg; Lenaerts, M.; Gérard, P. et al

in Olesen, J.; Schoenen, Jean (Eds.) Tension-Type Headache: classification, mechanisms and treatment (Frontiers in Headache Research) (1993)

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See detailMeasurements of EMG activity of pericranial muscles in tension-type headache
MAERTENS DE NOORDHOUT, Alain ULg; Schoenen, Jean ULg

in Olesen, J.; Schoenen, Jean (Eds.) Tension-Type Headache: classification, mechanisms and treatment (Frontiers in Headache Research) (1993)

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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 detailEffect of digital nerve stimuli on responses to electrical or magnetic stimulation of the human brain.
MAERTENS DE NOORDHOUT, Alain ULg; Rothwell, J. C.; Day, B. L. et al

in Journal of Physiology (1992), 447

1. Reflexes were elicited in the first dorsal interosseous muscle of seven normal subjects by electrical stimulation of the digital nerves of the index finger at 3 times perceptual threshold while ... [more ▼]

1. Reflexes were elicited in the first dorsal interosseous muscle of seven normal subjects by electrical stimulation of the digital nerves of the index finger at 3 times perceptual threshold while subjects maintained a constant voluntary contraction of the muscle. The average response in the surface-rectified electromyogram (EMG) consisted of an early inhibitory (I1) component followed by a later excitation (E2). 2. Low intensity anodal electrical or magnetic scalp stimuli were given over the motor cortex in order to elicit muscle responses within the period of the I1 and E2 reflex components. 3. Compared with control responses elicited in the absence of digital nerve stimulation, responses to electrical cortex stimulation were suppressed in the I1 period and facilitated during the E2 period of the reflex. In contrast, responses evoked by magnetic stimulation were suppressed during I1 and also for the first 10 ms or so of the E2 response. Magnetically evoked responses were facilitated during the later part of the E2 reflex. 4. Similar effects were seen when the probability of firing of single motor units was studied. 5. In three subjects, small taps were given to the abducted index finger in order to stretch the first dorsal interosseous muscle and evoke reflexes which were of comparable size to the E2 reflex evoked by digital nerve stimulation. In contrast to the experiments in which digital nerve stimuli were given, responses evoked by magnetic stimulation over motor cortex were facilitated at all times during the course of the reflex evoked when the muscle was stretched. 6. We conclude that single electrical stimuli applied to the digital nerves can reduce for a short period the excitability of motor cortex to magnetic stimulation. This occurs at a time when the same stimulus is evoking an excitatory (E2) reflex in the average surface-rectified EMG. [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 spondylotic myelopathy
MAERTENS DE NOORDHOUT, Alain ULg

in Lissens, M. A. (Ed.) Clinical Applications of magnetic transcranial stimulation (1992)

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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 detailCorrelation of phasic muscle strength and corticomotoneuron conduction time in multiple sclerosis.
van der Kamp, W.; MAERTENS DE NOORDHOUT, Alain ULg; Thompson, P. D. et al

in Annals of Neurology (1991), 29(1), 6-12

Central motor conduction times for the adductor pollicis muscle, the twitch force of that muscle to scalp magnetic motor cortex stimulation, and the maximum force of phasic voluntary contraction of the ... [more ▼]

Central motor conduction times for the adductor pollicis muscle, the twitch force of that muscle to scalp magnetic motor cortex stimulation, and the maximum force of phasic voluntary contraction of the same muscle were measured in 15 patients with multiple sclerosis. Two tests of manual dexterity of the same hand also were studied: the Purdue pegboard test, and the maximal frequency of a scissors movement of the thumb and index finger. The patients had normal strength or minimal weakness of the intrinsic muscles of the hand on clinical examination. The mean central motor conduction times for the adductor pollicis muscle for the patients were longer than normal, the peak twitch force of the adductor pollicis muscle evoked by cortical stimulation and the maximum force of a phasic voluntary contraction of the adductor pollicis muscle were smaller than normal. There were strong correlations between all these measures. Central motor conduction time in the patients was inversely correlated with voluntary phasic force and the twitch force after cortical stimulation. That is, the longer the central motor conduction time, the weaker the force. Prolonged central motor conduction time is likely to be accompanied by conduction block in corticomotoneuron pathways. The correlation of central motor conduction time with voluntary phasic force and the twitch force most likely reflects the degree of conduction block and temporal dispersion rather than delay in conduction per se. These results indicate that objective assessments of phasic muscle strength may reveal correlations with central motor conduction time that are not evident on conventional clinical examination which assesses tonic muscle contraction strength.(ABSTRACT TRUNCATED AT 250 WORDS) [less ▲]

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See detailStimulation Percutanée du cortex moteur chez l'homme. Données physiologiques et utilisation clinique
MAERTENS DE NOORDHOUT, Alain ULg

Thèse d’agrégation de l’enseignement supérieur (1991)

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