Swiss Narcolepsy Scale

The Swiss Narcolepsy Scale (SNS) is a brief subjective questionnaire that screens for the occurrence of several behavioral symptoms that may be associated with narcolepsy with cataplexy.¹

AASM provides quality measures for managing patients with narcolepsy²

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Features of the SNS

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Purpose:

Designed to screen for a symptom profile that might be suggestive of narcolepsy with cataplexy¹

Population:

Patients with excessive daytime sleepiness whom the clinician may want to screen for potential narcolepsy with cataplexy³

Assessments:

Measures frequency of 5 potential symptoms¹:

Q¹

–

Inability to fall asleep

Q²

–

Feeling bad or not well rested in the morning

Q³

–

Taking a nap during the day

Q⁴

–

Weak knees/buckling of the knees during emotions such as laughing, happiness, or anger

Q⁵

–

Sagging of the jaw during emotions such as laughing, happiness, or anger

Method:

Patient self-report¹

Time required:

Consists of 5 questions and takes only a few minutes to complete¹

Scoring:

Frequency for each behavioral complaint is rated on a 5-point scale, from 1, indicating “never,” to 5, indicating “almost always.” Each question is weighted by a positive or negative factor, with the score calculated using the following equation: (6×Q¹ + 9×Q² – 5×Q³– 11×Q⁴ – 13×Q⁵ + 20).^1,3

Interpretation:

An SNS score <0 is suggestive of narcolepsy with cataplexy.^1,3

Validation:

In 1 study of patients with narcolepsy with cataplexy, an SNS score <0 was shown to have a sensitivity of 96% and specificity of 98%.³

A narcolepsy diagnosis should be established by a sleep specialist using a clinical interview and a nighttime polysomnogram (PSG) followed by a multiple sleep latency test (MSLT) performed under standardized conditions.⁴

The Swiss Narcolepsy Scale is copyrighted and reproduced with permission of the authors. Unauthorized copying, printing or distribution is strictly prohibited.

References

Bassetti CL. Spectrum of narcolepsy. In: Baumann CR, Bassetti CL, Scammell TE, eds. Narcolepsy: Pathophysiology, Diagnosis, and Treatment. Springer Science+Business Media; 2011:309-319.
Krahn LE, Hershner S, Loeding LD, et al. Quality measures for the care of patients with narcolepsy. J Clin Sleep Med. 2015;11(3):335-355.
Sturzenegger C, Bassetti CL. The clinical spectrum of narcolepsy with cataplexy: a reappraisal. J Sleep Res. 2004;13(4):395-406.
American Academy of Sleep Medicine. Central disorders of hypersomnolence. In: The International Classification of Sleep Disorders – Third Edition (ICSD-3) Online Version. Darien, IL: American Academy of Sleep Medicine; 2014.