Laura Solieri

Motor pattern of periodic limb movements during sleep

Background: The pathophysiology of periodic limb movements in sleep (PLMS) in restless legs syndrome (RLS) is unclear. Objective: The authors neurophysiologically investigated PLMS in patients with idiopathic RLS in order to obtain information on the origin and pathophysiology of the movements. Methods: Ten patients with idiopathic RLS underwent electromyography with nerve conduction velocity (EMG-CV), somatosensory evoked potentials (SEPs), transcranial magnetic stimulation (TMS), nocturnal videopolysomnography, and multiple sleep latency test. The authors analyzed 100 consecutive PLMS for each patient to determine how frequently each muscle was involved in the PLMS; how frequently EMG activity started in a given muscle; and the time delay and pattern of activation between the first and the other activated muscles. Results: EMG-CV, SEPs, and TMS findings were all normal; in PLMS, leg muscles were those more frequently involved, often with alternation of side. Axial muscles were rarely and upper limb muscles sometimes involved. The tibialis anterior was the most frequent starting muscle. There was no constant recruitment pattern from one PLMS episode to another, even in the same patient. There was no ordinate caudal or rostral spread of the EMG activity. Conclusion: The recruitment pattern indicates the engagement of different, independent, and sometimes unsynchronized generators for each PLMS. The authors hypothesize an abnormal hyperexcitability along the entire spinal cord, especially its lumbosacral and cervical segments, as the primary cause of PLMS, triggered by sleep-related factors located at a supraspinal but still unresolved level.

Reversible postural tachycardia syndrome due to inadvertent overuse of Red Bull

Postural tachycardia syndrome associated with a vasovagal reaction was recorded in a young volleyball player after an excess intake of Red Bull® as a refreshing energy drink. Considering the widespread use of Red Bull® among young people who are often unaware of the drink’s drug content, this case report suggest Red Bull® be considered a possible cause of orthostatic intolerance.

Cognitive function in peripheral autonomic disorders

Objective aims of the current study were 1) to evaluate global cognitive function in patients with autonomic failure (AF) of peripheral origin and 2) to investigate the effect of a documented fall in blood pressure (BP) fulfilling the criteria for orthostatic hypotension (OH) on cognitive performances. Methods we assessed 12 consecutive patients (10 males, 68±7 years old) with pure AF (PAF) or autoimmune autonomic neuropathy (AAN) and 12 age- and gender-matched controls. All patients had no clinical signs of central nervous system involvement and normal brain CT/MRI scan. Cognitive function was assessed on two consecutive days in 3 conditions: on day 1, while sitting, by means of a comprehensive battery of neuropsychological tests; on day 2, while tilted (HUT) and during supine rest (supine) in a randomized manner. BP and heart rate (HR) were continuously recorded non-invasively for the whole duration of the examination. Results patients with PAF or AAN displayed a preserved global cognitive function while sitting. However, compared to supine assessment, during HUT patients scored significantly worse during the Trail Making Test A and B, Barrage test, Analogies test, Immediate Visual Memory, Span Forward and Span Backward test. Pathological scores, with regard to Italian normative range values, were observed only during HUT in the Barrage test and in the Analogies test in 3 and 6 patients respectively. On the contrary, in healthy controls, results to neuropsychological tests were not significantly different, during HUT compared to supine rest. Conclusions these data demonstrate that patients with PAF and AAN present a normal sitting global cognitive evaluation. However, their executive functions worsen significantly during the orthostatic challenge, possibly because of transient frontal lobes hypoperfusion.

Tilt-induced cardioinhibitory syncope: a follow-up study in 16 patients

IntroductionThe exact clinical and prognostic significance and the therapeutic implications of asystole induced by head-up tilt test are still a matter of debate.MethodsWe assessed, by means of a semi-structured interview, the long-term outcome of cardioinhibitory syncope in all the patients who presented a tilt-induced sinus arrest of more than 3 s in our Autonomic Unit between 1996 and 2010.ConclusionsAlthough syncopal recurrences were common, tilt-induced asystole did not imply a poor prognosis in terms of death or major therapeutic procedures.

Letter re: Effects of orthostatic hypotension on cognition in Parkinson disease

We read with interest the article by Centi et al.,1 which investigated the relation between orthostatic hypotension (OH) and posture-mediated cognitive impairment in 18 patients with idiopathic Parkinson disease (PD) with OH (PDOH) and 19 patients with PD without OH and 18 controls.1 The authors demonstrated that, during upright posture, PDOH exhibited a transient wider range of deficits in executive function, memory, and visuospatial function in excess of those found in PD without OH.