Excessive daytime sleepiness in patients with idiopathic normal pressure hydrocephalus: A controlled cross-sectional...

Idiopathic normal pressure hydrocephalus (iNPH) is characterized by gait disturbance, cognitive impairment, and urinary incontinence, yet non-motor symptoms such as sleep disturbances remain underexplored.

To investigate subjective daytime sleepiness and sleep apnea in patients with iNPH compared with healthy controls, and to assess their association with disease severity.

In this cross-sectional study, 46 iNPH patients and 74 age- and sex-matched controls were evaluated with the Epworth Sleepiness Scale (ESS). Apnea was assessed using a semi-structured frequency interview. Disease severity was rated with the NPH grading scale and MDS-UPDRS-3. Group comparisons and correlation analyses were performed.

ESS scores were significantly higher in iNPH patients (10.3 ± 7.1) than in controls (6.8 ± 5.6, p = 0.008), and this difference remained after adjusting for age and BMI. No significant associations were observed between ESS scores and motor or cognitive severity measures. Apnea frequency did not differ significantly between groups and showed no relationship with disease severity.

Excessive daytime sleepiness is common in iNPH and appears independently of motor or cognitive burden, suggesting it may be an underrecognized non-motor feature. Further studies incorporating objective sleep assessments and advanced neuroimaging are warranted to clarify underlying mechanisms and explore potential therapeutic implications, including the role of sleep-focused interventions.