My MSLT Experience: August 29th, 2011

MSLT Results (August 29, 2011)

The Multiple Sleep Latency Test (MSLT) was conducted on August 29, 2011. The test consisted of a series of four monitored nap opportunities throughout the day. Here are the summarized results from the official report:

Nap	Lights Out	Sleep Onset	Lights On	Time in Bed	Total Sleep Time	Sleep Latency	REM Latency
1	8:26:29 AM	8:32:29 AM	8:59:29 AM	00:33:00	00:25:00	00:06:00	—
2	10:39:13 AM	10:44:43 AM	11:05:13 AM	00:26:00	00:20:00	00:05:00	—
3	12:58:43 PM	1:05:13 PM	1:29:13 PM	00:31:00	00:23:00	00:06:30	—
4	1:37:45 PM	2:17:46 PM	3:44:46 PM	00:27:00	00:20:00	00:04:00	—

• Average sleep latency (4 naps): 4 minutes, 45 seconds
• Average REM latency: 0 (no REM detected during naps)

The hypnogram and latencies evolution graph from the report show consistently short sleep latencies for each nap, which is a key diagnostic feature of narcolepsy. No REM sleep was observed during the naps, but the rapid sleep onset is significant.

Additional Criteria for Narcolepsy Diagnosis

While the MSLT is the gold standard for diagnosing narcolepsy, other criteria may be considered, especially if the test results are inconclusive:

• Clinical symptoms:
  • Excessive daytime sleepiness (EDS) for at least 3 months.
  • Cataplexy (sudden loss of muscle tone triggered by emotions), which is highly specific for narcolepsy type 1.
  • Sleep paralysis and hypnagogic/hypnopompic hallucinations.
• Exclusion of other causes:
  • Ruling out insufficient sleep, untreated sleep apnea, or other medical/psychiatric conditions that could explain the symptoms.
• CSF hypocretin-1 (orexin-A) measurement:
  • Low or undetectable levels in cerebrospinal fluid are diagnostic for narcolepsy type 1, even if SOREMPs are absent.
• Family history and genetic markers:
  • Presence of HLA DQB1*06:02 allele is strongly associated with narcolepsy type 1.

A sleep specialist will consider your full clinical picture, not just test results, when making a diagnosis.