Sleep Abnormalities and Embolic Stroke of Undetermined Source

Embolic stroke of undetermined source (ESUS) is associated with elevated periodic limb movements (PLMs) and increased sleep onset latency, suggesting possible multifactorial underlying pathophysiology of ESUS, according to study results published in Stroke.

ESUS is a subgroup of stroke of undetermined cause that appears to be present in ≤25% of all patients with stroke. Many believe that ESUS is simply an undetected cardioembolic source, but others believe that is unlikely. The goal of the current study was to explore the pathophysiology of ESUS by investigating the association between ESUS and sleep abnormalities, including obstructive sleep apnea (OSA), PLMs, and impaired sleep architecture.

The study cohort included patients with a history of imaging-confirmed ischemic stroke, and in-laboratory polysomnography or home sleep apnea test within 1 year of stroke. Strokes were classified according to various mechanisms and were compared with the presence of sleep disorders.

Of 403 potential participants, the study cohort included 209 patients. Of these, 76 were diagnosed with OSA, and these patients were older (P <.001), more likely to be male (P <.001), and had a greater body mass index (P =.03), compared to those without OSA.

While there was no significant difference in OSA status between ESUS and other causes of stroke (P =.585), researchers noted significantly more cardioembolic stroke patients had OSA compared to those with other stroke mechanisms (P=.018). Furthermore, left atrial dilatation was significantly more common among patients with cardioembolic stroke (P =.0177).

Patients with ESUS were significantly more likely to have an elevated PLM index (P =.037) and prolonged sleep onset latency (P =0.0166), compared to patients with other causes of stroke.

The researchers noted several study limitations, including the use of home sleep apnea test although polysomnography is the gold standard, and exclusion of patients with significant physical impairment.

“This study found that ESUS was not associated with markers of cardioembolic stroke (OSA and LAD) but was rather associated with elevated PLMs and increased sleep onset latency. We also confirmed previous findings that OSA and LAD are associated with cardioembolic stroke,” concluded the researchers.

Reference

Dharmakulaseelan L, Chan-Smyth N, Black SE, Swartz RH, Murray BJ, Boulos MI. Embolic stroke of undetermined source and sleep disorders [published online ahead of print, 2020 Feb 11]. Stroke. doi:10.1161/STROKEAHA.119.028796