We studied the effects of intravenous immunoglobulin (IVIg) in 12 patients with motor neuron syndromes associated with high titers of anti-GM1 antibodies. Five of the patients had conduction blocks. The study design was a double-blind, placebo-controlled, crossover trial with IVIg (0.4 g/kg body weight per day injected for 5 consecutive days). We evaluated the patients before and 5, 28, and 56 days after drug administration using a computerized analyzer for muscle strength, the Norris scale for disability, motor nerve conduction velocities for patients with conduction blocks, and measurements of immunologic markers. Compared with placebo, IVIg induced a significant increase in muscle strength only in the patients with conduction blocks.

Our results confirm that STN stimulation performed under controlled GA is efficient and has similar short-term and long-term motor effects than intervention under local anaesthesia. Furthermore, this specific procedure is not associated with more adverse events. The success of such an intervention requires strict anaesthetic monitoring and accurate STN identification.

Yawning and spontaneous blink rate (SBR) are two physiological reflexes which have been incompletely examined but one neurobiological step of these two behaviours seems, at least in part, dopamine‐dependent. The reference dopaminergic agonist, apomorphine hydrochloride (0.5, 1, and 2 micrograms kg‐1 s.c.), was compared with a placebo in a double‐blind latin‐square design, and was shown to induce yawning and increase SBR in a population of eight healthy volunteers. These two behavioral effects were not dose‐related. The individual SBR differences were correlated with the individual number of yawns for all the four treatments at the 10‐30 min interval. Thus, parallel yawning and SBR behaviour suggests a similar pharmacological mechanism. Apomorphine‐ induced yawning and blinking may be therefore of use in the evaluation of central dopaminergic pathways in man.