Idiopathic insomnia life long inability to obtain adequate sleep and is presumably due to an abnormality of the neurologic control of the sleep-wake system.
The disorder may be due to a neurochemical imbalance of either the arousal system or the many sleep-inducing and sleep-maintaining systems (e.g., the rap-he nuclei, medial fore-brain area, etc.).
Some patients may merely fall toward the extremely wakeful end of a normal distribution curve. In others, actual dysfunctions or lesions rare exist within the sleep-wake system, be they neuroanatomic, neurophysiologic, or neurochemical.
Theoretically, either idiopathic hypersomnia within the arousal system or hypoactivity within the sleep system may cause idiopathic insomnia.
In any case, the life long and serious insomnia of these patients cannot be explained by either psychologic trauma starting in early childhood or medical problems, such as pain or allergies, that originate outside of the sleep wake system.
Chronically poor sleep in general leads to decreased feelings of well-being during the day.
In serious idiopathic insomnia, daytime functioning may be so severely disrupted that patients do not have the stamina to hold a job.
In most patients psychologic functioning remains remarkably normal as long as the sleep disturbance is either mild or moderate. Such patients have adapted to the chronic sleep loss and have learned to not focus on their problem.
It ranges from mild to severe, and includes some of the worst forms of insomnia ever recorded in a sleep laboratory.
Sleep latencies are typically long, and sleep efficiency is often very poor.
Typically, idiopathic insomniacs show long periods of rapid eye movement sleep that are devoid of any eye movements. Paradoxically, idiopathic insomniacs may show fewer body movements per unit of sleep time than do normal sleepers or other insomniacs.
Causes of Idiopathic Insomnia Disorder
It seems almost impossible to lead a life of chronic insomnia without developing other factors complicating the insomnia, such as poor sleep hygiene, learned maladaptive associations aggravating insomnia, or mental disturbances.
This is diagnosed when the history of a serious sleep disturbance can be traced to early childhood, markedly predating the occurrence of other sleep-disturbing factors, and when, in the opinion of the diagnostician, the imbalances in the sleep-wake system play a paramount role.
Whereas the short sleeper awakens refreshed and shows no detrimental daytime effects secondary to short sleep, patients with this type of insomnia clearly need more sleep than they can obtain, leading them to develop strategies to increase daytime vigilance and deal with chronic fatigue.
The innate predisposition toward poor sleep that is often seen in patients with physiologic insomnia is less serious but clearly lies on a continuum with the sleep disturbances shown in idiopathic insomnia.
Psychophysiologic insomnia is diagnosed if the inherent predisposition toward poor sleep is mild and needs the stress of maladaptive conditioning before bona fide insomnia develops, whereas this insomnia is relatively chronic and stable from early childhood on.
Psychologically, most patients with idiopathic insomnia are remarkably healthy, given their chronic lack of sleep.
If mental abnormalities are found, they clearly develop after insomnia has been established for years, if not decades. Also, this primary insomnia is relentless, continuing almost unvaried through both poor and good periods of emotional adaptation.