The Parkinson-Control study: a 1-year randomized, double-blind trial comparing piribedil (150 mg/day) with bromocriptine (25 mg/day) in early combination with levodopa in Parkinson's disease.

Dopamine agonists have been recommended as early treatment for Parkinson's disease (PD), alone or combined with levodopa. Piribedil is a non-ergot selective D(2)/D(3) agonist with alpha(2) antagonist properties shown to be effective in the treatment of PD. This 12-month international, randomized, double-blind trial aimed to assess the efficacy of piribedil 150 mg versus bromocriptine 25 mg, in early combination with levodopa in Stage I to III PD patients.

Changes in motor unit numbers in patients with ALS: a longitudinal study using the adapted multiple point stimulation method.

Method: The adapted multiple point stimulation (AMPS) method for calculating motor unit numbers (MUNE) was applied in 12 patients with amyotrophic lateral sclerosis (ALS) before riluzole therapy (T(0)) and again after 4, 8 and 12 months of treatment.

Results: Paired Student's t-test indicated a significant decrease of thenar MUNE and compound muscle action potential (CMAP) size at each 4-monthly interval, while average surface motor unit potential (SMUP) size did not change significantly over time. The rate of motor unit (MU) loss at month 4 was more than 20% in six patients (group 1) and less than 20% in six other patients (group 2).

Reduced excitability of the motor cortex in untreated patients with de novo idiopathic "grand mal" seizures.

Objectives: Transcranial magnetic stimulation (TMS) was used to investigate motor cortex excitability, intracortical excitatory, and inhibitory pathways in 18 patients having experienced a first "grand mal" seizure within 48 hours of the electrophysiological test. All had normal brain MRI, and were free of any treatment, drug, or alcohol misuse. Results were compared with those of 35 age matched normal volunteers.

Prognostic value of decremental responses to repetitive nerve stimulation in ALS patients.

Decrement of the thenar compound muscle action potentials (CMAP), after repetitive nerve stimulation (RNS) of the median nerve at 3 Hz, was evaluated in patients with ALS before riluzole therapy. CMAP size as well as motor unit number and size estimates were evaluated twice before and after 1 year of riluzole therapy. The correlation between decrement and CMAP size reduction per year was highly significant (r = 0.

Ipsilateral motor responses to focal transcranial magnetic stimulation in healthy subjects and acute-stroke patients.

Background And Purpose: Prevalence and characteristics of ipsilateral upper limb motor-evoked potentials (MEPs) elicited by focal transcranial magnetic stimulation (TMS) were compared in healthy subjects and patients with acute stroke.

Methods: Sixteen healthy subjects and 25 patients with acute stroke underwent focal TMS at maximum stimulator output over motor and premotor cortices. If present, MEPs evoked in muscles ipsilateral to TMS were analyzed for latency, amplitude, shape, and center of gravity (ie, preferential coil location to elicit them).

Number and relative size of thenar motor units in ALS patients: application of the adapted multiple point stimulation method.

In the present study, the adapted multiple point stimulation (AMPS) method was first applied to median innervated thenar muscles in 22 amyotrophic lateral sclerosis (ALS) patients who did not received any treatment. In all patients, a motor unit number estimate (MUNE) and an average surface-recorded motor unit action potential (S-MUAP) size have been derived even if the denervation was severe; and the results were reproducible. The thenar MUNE was less than the normal lower limit for age in 17 patients, and the mean MUNE (67.

Projections from basal ganglia to tegmentum: a subcortical route for explaining the pathophysiology of Parkinson's disease signs?

Functional changes in the organisation of neuronal circuitries are generally used to explain parkinsonian motor symptoms and levodopa-induced dyskinesias. Based on information from histology and neurophysiological microrecordings of specific basal ganglia nuclei, the most widely accepted scheme is based on a central loop which starts in the cerebral cortex, makes multiple relays in the basal ganglia, and returns to the cerebral cortex. Transcranial magnetic stimulation studies, however, reveal no significant differences in the excitability of the motor cortex between normal subjects and patients with Parkinson's disease.

Absence of response to early transcranial magnetic stimulation in ischemic stroke patients: prognostic value for hand motor recovery.

Background And Purpose: Transcranial magnetic stimulation (TMS) has been proposed as a prognostic tool in stroke patients. Most of the previous studies agree in considering the presence of motor-evoked potentials (MEPs) in the first days after a stroke as an indicator of good outcome. In the present study, we have assessed the prognostic value of the absence of response to early TMS on hand motor recovery in stroke patients with complete hand palsy at onset due to ischemia in the area of the middle cerebral artery.

Motor cortex inhibition is not impaired in patients with Alzheimer's disease: evidence from paired transcranial magnetic stimulation.

Motor cortex excitability was studied by transcranial magnetic stimulation (TMS) in 17 patients with Alzheimer's disease (AD). Resting and active thresholds for TMS were significantly reduced in AD patients compared to young and aged healthy subjects. The maximum amplitude of the motor response evoked by TMS was also significantly increased in AD patients.

Age-related changes in fastest and slowest conducting axons of thenar motor units.

Single thenar motor unit F waves (FMUPs) were collected from 23 healthy volunteers (age range 21-91 years, mean 46 +/- 20 SD). In each subject, 10 distinct FMUPs were recorded, using surface stimulating and recording electrodes, and the conduction velocity (CV) of each motor unit was calculated. The distribution of CVs (overall range 42-66 m/s; individual FMUP CV dispersion range 6-27% of the maximal FMUP CV) was close to those previously reported whatever the technique used.

Corticomotoneuronal synaptic connections in normal man: an electrophysiological study.

In order to determine the mono- or oligosynaptic character of connections between pyramidal axons and individual spinal motor neurons, we constructed peri-stimulus time histograms (PSTHs) of the firing probability of voluntarily activated single motor units (SMUs) of various upper and lower limb muscles upon slightly suprathreshold transcranial anodal electrical stimulations of the motor cortex in normal subjects. Weak anodal cortical stimuli are known to activate preferentially fast-conducting pyramidal axons directly, bypassing cell bodies and cortical interneurons. A narrow bin width (0.

[Cytochrome p450 and their implication in chemotherapy].

The hepatic cytochrome P450 enzymes (CYP450) play a prominent part in the metabolism of drugs, toxicants and some endogenous compounds. After a brief recall of their biochemical properties, the recent nomenclature is proposed. They are members of a large superfamily with various functions; the specialization of 3 families, CYP1, CYP2, CYP3 towards the metabolism of foreign and artificial compounds gives way to some evolutive considerations.

[Innovative new approaches in pharmacology].

After a brief recall of the molecular bases of the pharmacological actions, the two main ways of discovery of new drugs are described. On the one hand, the "deductive" approach starts with the elucidation of the pathogenic mechanisms and leads to selective drug designs for the appropriate receptors. The recent contributions of the molecular biology in this way are illustrated by some examples: "knock out" mice for the study of gene functions, discovery of new antibiotics thanks to genomic sequencing of bacteria, new pathogenic concepts about inflammation.

Motor and somatosensory evoked potentials in cervical spondylotic myelopathy.

We recorded upper and lower limb MEPs and SEPs in 55 patients with clinically suggestive and myelography-documented cervical cord compression due to spondylotic changes. MEPs were abnormal in biceps brachii of 21 patients (38%), in first dorsal interosseous muscle of the hand of 49 patients (89%) and in tibialis anterior of 47 patients (85%). Overall, MEP abnormalities were present in at least one muscle of 51/55 patients (93%).

Inhibition of the blink reflex R2 component after supraorbital and index finger stimulations is reduced in cluster headache: an indication for both segmental and suprasegmental dysfunction?

Peripheral as well as central mechanisms are thought to play a role in cluster headache pathogenesis. We have studied recovery curves of the R2 component of the blink reflex after conditioning by supraorbital or index finger stimuli in 10 episodic cluster headache (CH) patients during a cluster period and in 10 healthy controls. There was no significant change of R2 threshold, latency or area in CH patients.

Functional changes of brainstem reflexes in Parkinson's disease. Conditioning of the blink reflex R2 component by paired and index finger stimulation.

Recovery curves of the R2 component of the blink reflex have been studied in 10 control subjects and 13 parkinsonian patients both after ipsilateral paired stimulation of the supraorbital nerve and after index finger stimulation. In control subjects, both types of conditioning induced a comparable marked inhibition lasting more than 600 ms. In parkinsonian patients, inhibition was reduced after both conditionings.

Can motor recovery in stroke patients be predicted by early transcranial magnetic stimulation?

Background And Purpose: We used transcranial magnetic stimulation of the motor cortex to evaluate the functional state of corticospinal pathways innervating the first dorsal interosseous muscle of the hand in 26 patients suffering from a first-ever ischemic stroke in the middle cerebral artery territory.

Methods: All patients had complete hand palsy and were tested within the first 24 hours from stroke onset. Patients were also tested clinically with the MRC, Rankin, and National Institutes of Health (NIH) stroke scales at day 1 and with MRC and NIH scales and the Barthel Index at day 14.

Intraoperative localisation of the primary motor cortex using single electrical stimuli.

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.