Routine Retesting Not Required for Stable Narcolepsy
You do not need to repeat polysomnography (PSG) or Multiple Sleep Latency Testing (MSLT) for a patient with narcolepsy diagnosed 10 years ago if their symptoms remain stable and well-controlled on current management. 1
When Retesting IS Indicated
Repeat PSG and/or MSLT should only be performed when there is:
Exacerbation of symptoms including worsening sleepiness, new or worsening cataplexy, sleep paralysis, hypnagogic hallucinations, or behavioral abnormalities 1
Treatment failure where previously well-controlled symptoms deteriorate despite medication adherence 1
Suspected new sleep disorder such as obstructive sleep apnea or periodic limb movements, which are more common in older narcolepsy patients and can worsen previously controlled symptoms 2
Diagnostic uncertainty if the original diagnosis is being questioned or was made without adequate objective testing 3
Ongoing Management Without Retesting
For stable patients, appropriate follow-up involves:
Symptom monitoring using the Epworth Sleepiness Scale (ESS) at each visit to track subjective sleepiness and treatment response 1
Medication monitoring for adverse effects including hypertension, palpitations, arrhythmias, irritability, psychosis, excessive stimulation, or nocturnal sleep disturbances 1
Functional assessment evaluating residual impairments in daily activities, since medications like modafinil typically improve but do not eliminate sleepiness 1
Occupational and social support to assist with ongoing disability accommodations related to excessive sleepiness 1
Clinical Rationale
Narcolepsy is a lifelong disorder requiring ongoing management but is not progressive in nature 1, 2. The original diagnostic testing (PSG followed by MSLT showing mean sleep latency ≤8 minutes with ≥2 sleep-onset REM periods) remains valid indefinitely unless clinical circumstances change 3, 2, 4. Repeating expensive and time-consuming sleep studies in stable patients provides no additional diagnostic or therapeutic value.
Important Caveat for Older Adults
Be vigilant for new sleep disorders that commonly emerge with aging, particularly obstructive sleep apnea and periodic limb movements, which can masquerade as worsening narcolepsy 2. If symptoms deteriorate, PSG is warranted to exclude these treatable conditions before attributing changes to narcolepsy progression 1.