Excellent response to levetiracetam for recurrent prolonged sleep attacks in an 18-year-old male: a case report

Abstract

Background

Sleep disorders are a common health problem that can be classified into many types that are distinguished by their history and characteristics. In this case report, we discuss a case of a patient suffering from recurrent unusual prolonged sleep attacks lasting up to 9 days that responded excellently to levetiracetam.

Case presentation

An 18-year-old Syrian male patient presented to the neurology department complaining of recurrent prolonged sleep episodes lasting for 9 days. Although Kleine–Levin syndrome was suspected, the history and investigations ruled it out. The patient was then treated with levetiracetam as a trial, and the response was excellent.

Conclusion

This case is a rare and unusual sleep disorder that does not match any of the known sleep disorders. What makes the case unique is the unexpected response to levetiracetam.

Background

Humans spend about a third of their lives sleeping [1]. There are two main sleep stages in humans: rapid eye movement (REM) and non-rapid eye movement (NREM), which are distinguished by their brain wave patterns, muscle tone, and eye movements. These stages form a cycle that lasts about 90 min, and humans typically go through 4–6 of these cycles each night [2]. Sleep disorders are a group of conditions that are characterized by abnormal sleep patterns. They can significantly affect quality of life and overall health, and are among the most common health problems. There are several types of sleep disorders, including: insomnia, which is the most common and affects about one-third of the population; sleep-disordered breathing (SDB), such as central sleep apnea (CSA) and obstructive sleep apnea (OSA), in which obesity is a major contributing factor; circadian rhythm sleep–wake disorders (CRSD); parasomnias, which include sleepwalking and nightmare disorder; sleep-related movement disorders, such as restless legs syndrome (RLS); and central disorders of hypersomnolence, such as narcolepsy, idiopathic hypersomnia (IH), and Kleine–Levin syndrome (KLS) [3]. In this case report, we discuss the case of a patient with an unusual sleep disorder characterized by recurrent attacks of prolonged sleep.

Case presentation

An 18-year-old full-term Syrian male with five brothers and two sisters, one of whom has schizophrenia, presented to the neurology department with a complaint described by his mother as an episode of prolonged sleep lasting for 9 days, during which he was helped up to eat and use the bathroom by his parents. This had recurred four times in the previous year, with most episodes following exertion and stress. The patient had no history of behavioral problems such as aggression or mood disorders or any history suggestive of nocturnal epilepsy or narcolepsy. He had no history of psychiatric disorders. The patient had hyperphagia, was overweight, and experienced cognitive impairment following the episode. Blood tests, thyroid function tests, and brain magnetic resonance imaging (MRI) were all normal. Electroencephalography (EEG) was performed for a duration of 3 hours. The impression was mild to moderate focal neuronal dysfunction, but no epileptic discharges were observed. On the basis of the patient’s history and background, KLS was suspected, and the patient was sent for a sleep study, which showed no evidence of OSA, KLS (Fig. 1; Table 1), IH, or narcolepsy (Table 2). After the sleep study results, the patient was initially treated with stimulant pills (modafinil and melatonin), but he did not improve or show a significant response, so these medications were stopped. The patient was then treated with levetiracetam 500 mg twice daily and followed up for 6 months as part of a trial to improve his condition. The patient did not suffer from any attacks during the 6 months following the start of treatment. EEG and sleep studies were performed at the end of the aforementioned period and showed normal results. The patient continued treatment with the previously mentioned medication without any new episodes or side effects, and the patient was followed up with periodic visits to the neurology department.

Fig. 1

Polysomnography findings (a sleep study using electroencephalography): normal study; no evidence of obstructive sleep apnea or Kleine–Levin syndrome/recurrent hypersomnia

Table 1 Polysomnograghy study findings

Table 2 Mean sleep latency test (MSLT) results show no evidence of narcolepsy or idiopathic hypersomnia (IH)

Discussion

Sleep disorders are a very common condition among the population and can be caused by psychological, social, or even organic disorders [1]. As mentioned above, sleep disorders have several types, which are classified according to the International Classification of Sleep Disorders (ICSD) into insomnia, SDB, CRSD, parasomnia, sleep-related movement disorder, and central disorders of hypersomnolence [3]. Since the patient in our case suffers from hypersomnia, we detail the disorders characterized by hypersomnia as differential diagnoses in this discussion. Idiopathic hypersomnia (IH) is a rare sleep disorder that was first described in 1956. It is characterized by excessive daytime sleepiness with long, uncontrolled naps, an urgent need for sleep, and difficulty awakening despite sleeping for an average number of hours during the night for a period of 3 months. IH is a central neurological disorder, and the pathophysiology responsible for its occurrence is not fully understood, making its diagnosis and treatment a challenge for clinical practitioners. However, its occurrence is associated with sudden changes in sleep habits, stress, and mild head trauma, which may lead to hyperactivity of the sleep centers. Patients usually complain of daytime naps (more than 1 hour), but sleep attacks are not usually recorded frequently, which makes this differential diagnosis far from our case. In addition, one of the diagnostic criteria for IH is that the multiple sleep latency test (MSLT) must be less than 8 minutes, which does not correspond to the MSLT performed [4]. Narcolepsy is a disorder of REM sleep characterized by recurrent attacks of irresistible daytime sleepiness, and it is divided into type 1 and type 2. Type 1 is caused by a loss of hypocretin-containing neurons, and hypocretin levels in cerebrospinal fluid (CSF) can be used for diagnosis as they are virtually absent. Cataplexy in type 1 is a form of bilateral muscle weakness that does not involve loss of consciousness. Type 2 narcolepsy is not associated with cataplexy and has an unclear etiology. To diagnose narcolepsy, symptoms must occur at least three times a week for the past 3 months, the MSLT must be less than 8 minutes (in our case 8.4 minutes), and there must be two or more sleep-onset REM periods [5]. These diagnostic criteria are not met in our case, so narcolepsy is ruled out on the basis of the clinical history and investigations, such as polysomnography (PSG) and MSLT. KLS is a rare disorder that is often included in the differential diagnosis of hypersomnia. Its cause is unknown, and there is no specific drug for management. The main symptoms of KLS include hypersomnia, hypersexuality, compulsive eating behavior, behavioral disturbances such as aggression and abnormal speech, and memory deficits. Patients typically present with recurrent episodes of prolonged sleep lasting from 12 to 24 hours per day. Diagnosis is clinical and is made by excluding other conditions, such as narcolepsy, temporal lobe epilepsy, and psychiatric conditions such as depression and bipolar disorder [6]. In this case, there may have been some overlap with KLS in terms of hyperphagia and hypersomnia, but the other symptoms, such as memory deficits, behavioral disturbances, hypersexuality, and abnormal speech, were not present. Therefore, KLS was ruled out on the basis of the history and PSG. According to the above, we find that none of the disorders mentioned as differential diagnoses can be fully and clearly applied to our patient’s case, though KLS can be considered the closest diagnosis to some extent. However, this patient cannot be diagnosed with KLS owing to the incompleteness of the diagnostic criteria discussed. This makes this case unique, in addition to the patient’s excellent response to levetiracetam; one study showed no significant effect of levetiracetam on sleep structure in general [7], which makes this case even more rare.

Conclusion

This case is interesting because it is an unusual sleep disorder, as no similar cases have been reported in the medical literature, and it did not match the symptoms or criteria of any of the known sleep disorders. In addition, the unexpected response to levetiracetam, which has not been previously reported to have a significant effect on sleep structure, suggests that studies be conducted on the effect of this drug on patients with hypersomnia and other sleep disorders.