Woman asleep w many pillowsAuthor: Yasmin N. Aziz, MD

University of Cincinnati, Ohio, USA

Manuscript: High pillow and spontaneous vertebral artery dissection: A case-control study implicating “Shogun pillow syndrome”

We see them on a weekly basis—young patients stroke patients with dissection. Following a careful history seeking to identify trauma, systemic autoimmune disease, collagen disorders, and family history of similar events, many cases of dissection remain cryptogenic.1 In this study, the authors sought to determine if wake-up symptoms and vertebral artery dissection could be due to something seemingly benign: pillow use.  Specifically, the investigators aimed to identify if sleep positioning from pillow height (i.e., “high pillow” usage), was associated with spontaneous vertebral artery dissection (sVAD).

Consecutive patients with intra or extracranial sVAD in the National Cerebral and Cardiovascular Center, a Japanese stroke center, were considered for inclusion between March 2018 – January 2023 utilizing the 2021 European Stroke Organisation diagnostic criteria.2 Those with fibromuscular dysplasia, hereditary, iatrogenic, or severe traumatic causes of dissection were excluded.  Controls were age and sex-matched ischemic stroke patients secondary to causes other than sVAD.

Demographics, pillow use, and risk factors possibly related to high pillow use (i.e., esophageal reflux) were collected.  Additional variables such as wake-up onset, minor trauma, stroke scale, accompanying pain, concomitant diagnosis at presentation, as well as location of dissection were collected.  Pillow criteria, including height (measured at peak height prior to head placement), firmness, and neck angle (i.e., parallel, flexion, extension), were collected.  Specifically, height was divided into 3 categories: <12, ≥12, or ≥15 cm. After 1:1 matching, univariate logistic regression was used to determine the odds ratio of high pillow usage and sVAD.

There were 53 cases and 53 controls, of which 42% were women and median age was 49 years.  Increasing pillow height was associated with a greater odds of sVAD development (≥12cm: OR 2.89, 95% CI 1.13-7.43; ≥15cm: OR 10.6; 95% CI 1.30-87.8; p=0.007).  Importantly, in the sVAD group, 11.3% of patients had sVAD attributable to high pillow use based on prespecified criteria (pillow height ≥12cm, wake-up symptoms, and absence of preceding trauma).  In an exploratory analysis, neck flexion positioning and pillow hardness were identified as possible mediating factors.

The authors recognize limitations to be as follows: reporting bias due to the retrospective nature of the study, post-hoc pillow measurement, an exclusion of patients with subarachnoid hemorrhage, difficulty generalizing to Japanese patients, and an absence of data regarding other variables regarding sleep positioning, mattress firmness, etc., that may be important to sVAD development.

Novel to this study is the identification of high pillow use as a novel risk factor for sVAD development, with a suggested “dose-dependent” effect of pillow height.  The authors suggest that contralateral rotation during neck flexion, a factor identified as causing stress to the vertebral artery, may occur during restless sleep in the setting of a high pillow.  Further, the V4 segment comprised the majority location for dissection, a location that may endure increased stress due to dural compression.

Certainly, more work must be done to identify people who could benefit from prophylactic use of pillows <12cm.  Until that time, however, clinicians looking to unlock the cause of spontaneous vertebral artery dissection in the young may benefit from adding questions about sleep practices to their standing battery of questions.

Read the article in the European Stroke Journal


  1. Park KW, Park JS, Hwang SC, Im SB, Shin WH, Kim BT. Vertebral artery dissection: natural history, clinical features and therapeutic considerations. J Korean Neurosurg Soc. 2008;44:109-115. doi: 10.3340/jkns.2008.44.3.109
  2. Debette S, Mazighi M, Bijlenga P, Pezzini A, Koga M, Bersano A, Korv J, Haemmerli J, Canavero I, Tekiela P, et al. ESO guideline for the management of extracranial and intracranial artery dissection. Eur Stroke J. 2021;6:XXXIX-LXXXVIII. doi: 10.1177/23969873211046475

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