An 18-year-old man comes to the physician for daytime sleepiness lasting several months. The patient recently started college, has difficulty staying awake during classes, and often falls asleep suddenly even though he "gets a good night's sleep." He typically goes to bed at 2 am and sleeps until at least 9 am, usually later. The patient's sleep pattern at night is fragmented. He wakes frequently but is usually able to go back to sleep within a few minutes. He does not snore or wake up gasping. The patient feels like "someone is in the room with me when I'm just falling asleep and I sometimes hear my name being called." His past medical history is otherwise insignificant. The patient does not use tobacco or alcohol. Blood pressure is 120/70 mm Hg and heart rate is 70/min. His body mass index is 23 kg/m². The appropriate treatment is initiated, but the patient returns in 4 weeks and says that his symptoms have not improved. He recently had "some little troubles" in his family, and has felt sudden onset of muscle weakness and falls, especially during arguments with his family members. What is the best next step in management of this patient?

Question

Quizplus · Accepted Answer

Explanation: Cataplexy (CP) is the sudden onset of muscle weakness, often triggered by intense emotional episodes (eg, anger, laughing, surprise) and is a common symptom of narcolepsy. CP is a pathognomonic symptom that occurs in roughly 70% of patients with narcolepsy. Although stimulants and behavioral interventions are important initial steps in the treatment of sleepiness associated with narcolepsy, they may be insufficient for management of CP. Patients with CP can be treated with a serotonin-norepinephrine reuptake inhibitor (eg, venlafaxine) or selective serotonin reuptake inhibitor, and a tricyclic antidepressant can also be considered. Sodium oxybate (the salt form of gamma-hydroxybutyrate) can improve nocturnal sleep, relieve excessive daytime sleepiness and has anti-cataplectic properties; however, it is rarely used due to abuse potential and restrictive regulations. (Choice A) Clonazepam can be useful for treating sleep-related parasomnias, but it is not effective for CP. (Choice B) Lamotrigine is less effective than valproic acid for the treatment of absence seizures. (Choice C) Methylphenidate is a second-line stimulant used to treat narcolepsy. Its adrenergic activity may mildly improve CP, but it is usually not more effective than modafinil. (Choice D) Urgent neurosurgical consultation for shunt placement is the primary treatment for normal-pressure hydrocephalus. Educational objective: Cataplexy (CP) is the sudden loss of muscle tone triggered by strong emotions and is a common symptom of narcolepsy. Stimulant medications may mildly improve the symptoms but are often insufficient, especially if there is a significant safety risk. Other medications for CP include serotonin-norepinephrine reuptake inhibitors, selective serotonin reuptake inhibitors, tricyclic antidepressants, and sodium oxybate. References: Narcolepsy: clinical approach to etiology, diagnosis, and treatment. (http://www.ncbi.nlm.nih.gov/pubmed/22249574)

An 18-Year-Old Man Comes to the Physician for Daytime Sleepiness