Psychological problems not the sole explanation for sleep disorders: Experts call for neurological evaluation.

Psychological problems may not be the only reasons for disturbed sleep-wake cycles, according to experts speaking at the Meeting of the European Neurological Society in Prague. They are calling for a systematic neurological evaluation in order to detect, and treat in time, serious neurological disorders such as narcolepsy. New studies show REM sleep disorder may indicate the later onset of Parkinson's disease.

"Peace of mind is not all that is needed for a trouble-free sleep-wake cycle. "You also need a functioning brain," Prof Dr Claudio Bassetti (University Hospital of Neurology, Bern), president-elect of the European Neurological Society (ENS) told the 22nd ENS Meeting in Prague today. "Neurological disorders are still being underestimated as a cause of sleep disorders and are under-diagnosed."

More than 3,000 experts from all over the world are gathered in Prague to discuss the latest findings in their field. "There is particularly little public consciousness of narcolepsy," said Prof Bassetti. "More attention needs also to be paid to so-called REM sleep disorder, which is often a harbinger of Parkinson's disease. This could allow for counter-measures - even several years before the first signs of motor disorders."

Narcolepsy: underestimated and under-diagnosed sleep disorder which is as common as MS

Even for doctors, narcolepsy remains a puzzling phenomenon. Those affected by it suffer sudden attacks of excessive fatigue during the day during which dream sleep penetrates waking consciousness. This does not just affect the sleep-wake cycle, but also cognition, motor activity, and emotional reactions. Thus intense emotions such as laughter can lead to falls, because of loss of motor control (cataplexy).

"The latest epidemiological estimates suggest one in every 2,000 suffers from narcolepsy - which is about the same number as multiple sclerosis. The quality of life of those affected is dramatically reduced, to about the level of epilepsy patients," said Prof Bassetti. "But research of this disease is often neglected. Narcolepsy is also frequently under-diagnosed in clinical practice, even though the symptoms could be effectively treated."

Vaccination can trigger the disease

Despite very modest financial backing, it has recently been possible to achieve significant breakthroughs in the understanding of this complex medical condition; results were presented at the ENS Meeting in Prague. "We know there must be a genetic factor as well, because almost all narcolepsy patients share a very particular set of blood factors in their leukocytes. Although these are found in a quarter of the population, only one in 500 develops the disease. So there must," said Prof Bassetti, "be additional factors which trigger the outbreak of this illness in those who have a genetic predisposition to develop it.

Recent data show that infections and vaccinations may, on the basis of this genetic predisposition, be causing an autoimmune reaction; this in turn expresses itself in disturbances in the neuronal signalling network, and dysfunctions in several areas of the brain. It is becoming increasingly clear that one of these triggers is a vaccine against the H1N1 influenza virus. In a significant number of cases this was found to have been administered two to four months before the outbreak of narcolepsy."

Disturbance of REM sleep: a warning sign of Parkinson's disease

The ENS Meeting was also presented with new data on recently-discovered correlations between the REM sleep behaviour disorder and the development of Parkinson's disease. "REM sleep disorder is the loss of so-called physiological paralysis which - in healthy people - ensures their muscles are relaxed during dream sleep, and prevents them from giving physical expression to what they imagine they are experiencing in their dreams," said Prof Bassetti. Absent this inhibition those affected scream, kick and lash out, hurting themselves and their partners during the REM sleep phase.

"We have now found out that the loss of physiological motor inhibition during dream sleep arises from a brain process that is typical, inter alia, for Parkinson's disease. It is a fact that many Parkinson's patients suffer from REM Sleep disorder during the night, years before the first motor disturbances become noticeable during the day," said Prof Bassetti. "We now need to make determined efforts to ensure that this knowledge is being introduced in both neurological and general medical education. Since there are reasonable expectations that a new group of drugs will prevent or at least slow down Parkinson's disease, early diagnosis and rapid initiation of therapy could be crucial for the quality of life of those affected."

Movement during sleep as an indication of epilepsy

There can be other causes for crying out, or for sudden movements, during sleep. "About a third of all epileptic seizures occur during sleep, appearing to be very similar to REM Sleep disorder," explained Prof Bassetti. "It is not easy to recognise. But epilepsy should always be considered where such symptoms appear. It can then be effectively treated with anti-epileptic drugs."

Sleep disturbances should be taken seriously

"These findings show that many conditions which appear, superficially, to be entirely the consequence of mental problems may in fact be signs of severe neurological diseases, and therefore need to be taken seriously," said Prof Bassetti. "We should pay more attention to this, because only once things have been clarified can we alleviate patients' sufferings".