A population susceptible to the development of sleep disorders is people who have experienced a traumatic brain injury (TBI). Because many researchers have focused on this issue, a systematic review was conducted to synthesize their findings. According to their results, TBI individuals are most disproportionately at risk for developing narcolepsy, obstructive sleep apnea, excessive daytime sleepiness, and insomnia.[20] The study's complete findings can be found in the table below:

Ask your doctor for a referral to an ear, nose, and throat (ENT) specialist, who can evaluate whether you're a candidate for Continuous Positive Airway Pressure (CPAP), a specially designed nasal mask that prevents your nasal passages from collapsing and delivers air directly into your airway. If tongue position during sleep is causing your UARS, the doctor may recommend a dental device that pushes the jaw and tongue forward and prevents the tongue from blocking the opening to the throat.

Sleep apnea is a common (and treatable) sleep disorder in which your breathing temporarily stops during sleep, awakening you frequently. If you have sleep apnea you may not remember these awakenings, but you’ll likely feel exhausted during the day, irritable and depressed, or see a decrease in your productivity. Sleep apnea is a serious and potentially life-threatening sleep disorder, so see a doctor right away and learn how to help yourself.
Recent studies have also linked sleep disturbances, neurogenesis and AD.[29] Indeed, it is now known that neurogenesis exists and that the subgranular zone and the subventricular zone keep on creating new neurons even in an adult brain.[29][34] These new cells are then incorporated into neuronal circuits and interestingly, the supragranular zone is found in the hippocampus.[29][34] These new cells will contribute to learning and memory and will play a role in the hippocampal-dependent memory.[29]
Sleep disturbances have been also observed in Alzheimer's disease (AD), affecting about 45% of its population.[22][24][26] Moreover, when it is based on caregiver reports this percentage is even higher, about 70%.[28] As well as in PD population, insomnia and hypersomnia are frequently recognized in AD patients, which have been associated with accumulation of Beta-amyloid, circadian rhythm sleep disorders (CRSD) and melatonin alteration.[22][24][28] Additionally, changes in sleep architecture are observed in AD too.[22][24][26] Even though with ageing the sleep architecture seems to change naturally, in AD patients it is aggravated. SWS is potentially decreased (sometimes totally absent), spindles and the time spent in REM sleep are also reduced, while its latency is increased.[28] The poorly sleep onset in AD has been also associated with dream-related hallucination, increased restlessness, wandering and agitation, that seem to be related with sundowning - a typical chronological phenomenon presented in the disease.[24][28]
Both night terrors and sleepwalking arise during NREM sleep and occur most often in children between the ages of 3 and 5 years old. A night terror can be dramatic: Your child may wake up screaming, but unable to explain the fear. Sometimes children who have night terrors remember a frightening image, but often they remember nothing. Night terrors are often more frightening for parents than for their child. Sleepwalkers can perform a range of activities -- some potentially dangerous, like leaving the house -- while they continue to sleep.
Some of the biggest differences between the 2nd and 3rd editions are how the various sleep disorders were divided into categories. The 2005 edition used 3 broad categories to organize all of the sleep disorders under either dysommnias (disorders making getting to sleep or staying asleep difficult), parasomnias (disorders that intrude into the sleep process), and sleep disorders associated with a mental, neurologic, or other medical disorders (disorders whose symptoms are not primary unto themselves but caused by other conditions).
Specialists in Sleep Medicine were originally certified by the American Board of Sleep Medicine, which still recognizes specialists. Those passing the Sleep Medicine Specialty Exam received the designation "diplomate of the ABSM." Sleep Medicine is now a recognized subspecialty within internal medicine, family medicine, pediatrics, otolaryngology, psychiatry and neurology in the United States. Certification in Sleep Medicine shows that the specialist:

Idiopathic hypersomnia: a chronic neurological disease similar to narcolepsy in which there is an increased amount of fatigue and sleep during the day. Patients who suffer from idiopathic hypersomnia cannot obtain a healthy amount of sleep for a regular day of activities. This hinders the patients' ability to perform well, and patients have to deal with this for the rest of their lives.[15]

In Alzheimer's disease, in addition to cognitive decline and memory impairment, there is also significant sleep disturbances with a modified sleep architecture.[30][29] The latter may consist in sleep fragmentation, a reduction in sleep duration, insomnia, an increase daytime naping, a decreased quantity og some sleep stages and a resemblance between some sleep stages (N1 and N2).[29] More than 65% of people with Alzheimer's disease suffer from this type of sleep disturbance.[29]
Restless leg syndrome (RLS) is an overwhelming need to move the legs. This urge is sometimes accompanied by a tingling sensation in the legs. While these symptoms can occur during the day, they are most prevalent at night. RLS is often associated with certain health conditions, including ADHD and Parkinson’s disease, but the exact cause isn’t always known.

The neurodegenerative conditions are commonly related to brain structures impairment, which might disrupt the states of sleep and wakefulness, circadian rhythm, motor or non motor functioning.[22][24] On the other hand, sleep disturbances are also frequently related to worsening patient's cognitive functioning, emotional state and quality of life.[24][27][28] Furthermore, these abnormal behavioural symptoms negatively contribute to overwhelming their relatives and caregivers.[24][27][28] Therefore, a deeper understanding of the relationship between sleep disorders and neurodegenerative diseases seems to be extremely important, mainly considering the limited research related to it and the increasing expectancy of life.[22][28]
In people who have restless legs syndrome, discomfort in the legs and feet peaks during the evening and night. They feel an urge to move their legs and feet to get temporary relief, often with excessive, rhythmic, or cyclic leg movements during sleep. This can delay sleep onset and cause brief awakening during sleep. Restless legs syndrome is a common problem among middle-aged and older adults.
None of these general approaches is sufficient for all patients with sleep disorders. Rather, the choice of a specific treatment depends on the patient's diagnosis, medical and psychiatric history, and preferences, as well as the expertise of the treating clinician. Often, behavioral/psychotherapeutic and pharmacological approaches are not incompatible and can effectively be combined to maximize therapeutic benefits. Management of sleep disturbances that are secondary to mental, medical, or substance abuse disorders should focus on the underlying conditions.
Recent studies have also linked sleep disturbances, neurogenesis and AD.[29] Indeed, it is now known that neurogenesis exists and that the subgranular zone and the subventricular zone keep on creating new neurons even in an adult brain.[29][34] These new cells are then incorporated into neuronal circuits and interestingly, the supragranular zone is found in the hippocampus.[29][34] These new cells will contribute to learning and memory and will play a role in the hippocampal-dependent memory.[29]
The decrease in the quantity and quality of the NREM SWS as well as the disturbances of sleep will therefore increase the AB plaques.[29][30] This will first take place at the hippocampus level, from which memory is dependent.[29][30] This will result in cell death at this level and will contribute to diminished memory performances and cognitive decline found in AD disease.[29]
Although more research should be done to increase the reliability of this method of treatment, research suggests that music therapy can improve sleep quality in acute and chronic sleep disorders. In one particular study, participants (18 years or older) who had experienced acute or chronic sleep disorders were put in a randomly controlled trial and their sleep efficiency (overall time asleep) was observed. In order to assess sleep quality, researchers used subjective measures (i.e. questionnaires) and objective measures (i.e. polysomnography). The results of the study suggest that music therapy did improve sleep quality in subjects with acute or chronic sleep disorders, however only when tested subjectively. Although these results are not fully conclusive and more research should be conducted, it still provides evidence that music therapy can be an effective treatment for sleep disorders.[47]

At the same time, it has been shown that memory consolidation in long-term memory (which depends on the hippocampus) occurs during NREM sleep.[29][33] This indicates that a decrease in the NREM sleep will result in less consolidation and therefore poorer memory performances in hippocampal-dependent long-term memory.[29][33] This drop in performance is one of the central symptoms of AD.[29]  

What to do: If you suspect you have a circadian rhythm disorder, take steps to get your body onto a regular sleep schedule. Choose a bedtime and wake-up time that work for you, and follow the same routine each day, even on weekends. This can be tough for those who have to get up early during the week but like to stay up later on weekends, but do your best to craft a compromise between your work week and weekend habits. The important thing is to avoid the trap of sleeping from 10 p.m. to 6 a.m. during the week, then suddenly shifting to late nights and late mornings on the weekends. This will inevitably leave you with insomnia on Sunday night, which in turn sets you up to start the week exhausted on Monday morning.