Hyperviscosity as a possible cause of positive acoustic evoked potential findings in patients with sleep apnea: a dual electrophysiological and hemorheological study.

OBJECTIVE: To test the hypothesis that blood hyperviscosity could account for the controversial results observed during electrophysiological evaluation of the brain stem in sleep apnea syndrome. METHODS: This was a prospective study of a sample of patients with sleep apnea who were participating in a stroke prevention evaluation. Participants were 610 male patients with obstructive sleep apnea, aged 30-55 years, without large vessel disease on Magnetic Resonance Angiography and neck Doppler sonography, and an infratentorial lesion on head magnetic resonance imaging. Brainstem auditory-evoked potential and hemorheological investigations were carried out. RESULTS: Forty-six percent (N=282) of the patients evidenced hyperviscosity and 53% (N=328) had normal rheological findings. Evoked potential changes appeared only in the hyperviscosity positive subgroup. Of these, 84% (N=239) evidenced BAEP changes with 24% (N=57) demonstrating sensorineuronal and 76% (N=182) demonstrating brain stem type abnormalities. After six months of CPAP therapy, hyperviscosity was normalized in 66% (N=159) of patients. BAEP wave III latency values were normalized in 70% (N=112) of these patients. CONCLUSIONS: Viscosity changes play an important role in the brainstem electrophysiological abnormalities in apnea patients. These abnormalities can be normalized after six months of CPAP therapy.

[Pramipexole therapy of restless legs syndrome]. / A nyugtalan láb szindróma pramipexolkezelésének tapasztalatai.

The restless legs syndrome is a disorder belonging to the family of movement disorders during sleep, often remains unrecognized, although it is the second most common cause of chronic sleep deficiency and daytime sleepiness. In accordance with international guidelines, pharmacotherapy of this disorder should begin with a dopamine agonist. Owing to their efficacy and favorable safety profile, newly introduced, selective dopamine agonists have become extensively used for this purpose. This study evaluated the efficacy of one of the products in this group, pramipexole. Fifty-one patients suffering from idiopathic restless legs syndrome underwent monotherapy with pramipexole in daily doses of 0.25 to 1.0 mg. Therapeutic efficacy was evaluated using three tools, i.e. follow-up questionnaires, actigraphy, and Forced Immobilisation Test. An excellent therapeutic effect was seen in more than 80 per cent of the study population. As shown by findings of the follow-up questionnaires, pramipexole resulted in substantial improvements of both daytime and nighttime symptoms of RLS. Actigraphy monitoring demonstrated a statistically significant increase in the ratio of time spent without limb movement to the time spent in bed; furthermore, the result of the Forced Immobilisation Test also improved. It seems fair to conclude from the findings of this study that pramipexole monotherapy is an effective treatment in restless legs syndrome.