Evaluation and Management of Sleep-Related Sexual Behavior (Sexsomnia)
This patient is exhibiting a parasomnia that requires immediate polysomnography to differentiate between somnambulism (NREM parasomnia) and REM sleep behavior disorder, as the treatment and prognosis differ dramatically between these conditions. 1
Initial Clinical Assessment
Key History Questions to Ask
- Timing and sleep stage: Does the patient recall dreaming during these episodes? If yes, this suggests RBD rather than somnambulism 2
- Complexity of behavior: Simple repetitive movements suggest somnambulism, while violent or complex motor activity with vocalizations suggests RBD 3
- Memory of events: Complete amnesia for the events is characteristic of both conditions 3
- Bed partner observations: Ask specifically about violent movements, screaming, angry vocalizations (RBD) versus calm ambulation (somnambulism) 3, 2
Medication and Substance Review
Identify and discontinue precipitating medications including TCAs, MAOIs, and SSRIs, which can induce or exacerbate parasomnias 4. Assess for alcohol and barbiturate withdrawal, as well as caffeine use, as these may trigger episodes 4.
Screen for Underlying Sleep Disorders
Critical: Ask about snoring, witnessed apneas, gasping, and daytime sleepiness, as sleep-disordered breathing frequently triggers somnambulism in adults 5. Also screen for restless legs syndrome and periodic limb movements 6.
Diagnostic Workup
Mandatory Testing
Polysomnography with video-audio monitoring is required for definitive diagnosis 1, 3. This is indicated when precipitous arousals occur with violent or injurious behavior 1.
Additional Testing Based on Clinical Findings
- Brain MRI: Obtain if there is evidence of abnormal neurologic activity, atypical features suggesting seizures, or any neurological abnormalities to evaluate for brainstem lesions, stroke, tumor, or demyelinating disease 4, 3
- Neurologic evaluation: Perform thorough neurologic examination, as parasomnias in adults often reflect psychopathology, significant stress, or organicity 7
Treatment Algorithm
If Somnambulism (NREM Parasomnia) is Diagnosed:
First priority: Treat underlying sleep-disordered breathing if present. All nasal CPAP-compliant patients with SDB-associated sleepwalking achieved complete control of sleepwalking 5. This is the most effective treatment approach 6, 5.
If no underlying sleep disorder: Use clonazepam 0.5-1 mg at bedtime 6. However, note that patients treated with benzodiazepines alone frequently report persistence of sleepwalking 5.
Avoid medications that worsen parasomnias (TCAs, MAOIs, SSRIs) unless specifically indicated for comorbid conditions 4
If REM Sleep Behavior Disorder is Diagnosed:
First-line pharmacotherapy: Melatonin (immediate-release) 3 mg at bedtime, which can be increased to 15 mg 2. Melatonin is preferred over clonazepam in patients with dementia, cognitive impairment, sleep apnea, or high fall risk 2.
Alternative treatment: Clonazepam 0.5-1 mg at bedtime has 90% effectiveness but carries higher risks in elderly patients 3
Critical prognostic information: Patients with idiopathic RBD have a 70% risk of developing α-synucleinopathy (Parkinson's disease, dementia with Lewy bodies, multiple system atrophy) within 12 years of diagnosis 2. Monitor for prodromal neurodegenerative symptoms at each visit 3.
Immediate Safety Measures (For Both Conditions)
Implement environmental safety measures immediately while awaiting diagnostic workup 4, 3:
- Remove dangerous objects from the bedroom 4, 3
- Pad sharp surfaces 4, 3
- Secure windows and lock doors 4
- Consider placing the mattress on the floor if fall risk is high 4
Follow-Up and Monitoring
- Monitor for treatment efficacy and sleep-related injuries at each visit 3
- For RBD patients: Assess for emerging parkinsonian symptoms (hyposmia, constipation, orthostatic hypotension) and cognitive changes 3
- Refer to neurology if prodromal neurodegenerative symptoms develop 3
- Refer to sleep specialist when diagnosis remains uncertain, initial treatment fails, or suspected underlying sleep disorders exist 2
Critical Pitfall to Avoid
Do not treat with benzodiazepines or behavioral therapy alone without first ruling out sleep-disordered breathing. The most common mistake is missing underlying SDB, which when treated successfully (with CPAP or surgery), completely resolves sleepwalking in the majority of adult cases 5. Treating with medications alone while missing SDB leads to treatment failure and persistent dangerous behaviors 5.