False-positive cases in multiple sleep latency test by accumulated sleep debt

Area of Science:

• Sleep Medicine
• Neurology

Background:

• The Multiple Sleep Latency Test (MSLT) objectively assesses sleepiness, typically following polysomnography (PSG).
• Standard protocols often require a 2-day stay, which may not resolve chronic sleep debt.
• Unresolved sleep debt can lead to inaccurate MSLT results and potential misdiagnosis of hypersomnia.

Purpose of the Study:

• To investigate the impact of chronic sleep debt on MSLT results.
• To determine if extending evaluation periods improves diagnostic accuracy for sleepiness disorders.

Main Methods:

• Twelve hypersomnolent males underwent two MSLTs: one after a single night of PSG and another after an extended stay (≥3 nights).
• Patients were selected based on increased sleep time during PSG compared to sleep logs and shortened sleep latency on PSG.
• Hospitalization was extended or patients were re-hospitalized to evaluate the effect of reduced sleep debt.

Main Results:

• Mean sleep latency significantly increased from 5.8 minutes on the first MSLT to 13.9 minutes on the second MSLT (P < .001).
• Five out of twelve patients shifted from having short sleep latencies to normal sleep latencies on the second MSLT.
• Extended evaluation periods helped prevent over-diagnosis in these cases.

Conclusions:

• Chronic sleep debt can lead to false-positive results on standard PSG and MSLT, manifesting as shortened sleep latencies.
• Patients undergoing sleepiness evaluations should consider extended hospitalization to mitigate chronic sleep debt.
• Accurate diagnosis of hypersomnia requires addressing and reducing pre-existing sleep debt.