1271 - The Mechanism of Surfer’s Myelopathy: Prolonged Back Hyperextension May Cause Positional Spinal Ischemia

Surfer’s Myelopathy (SM) is a rare, non-traumatic spinal cord injury that affects novice surfers. Described clinical and radiographic features are highly suggestive of spinal ischemic stroke. The observed difference in idling positions between novice (prone with back hyperextended) and experienced surfers (sitting up on the surfboard) has generated the hypothesized pathogenesis of position-induced spinal vascular insufficiency. However, existing data is limited to retrospective case reports recalling variable information. Therefore, the goal of this study is to systematically characterize the predisposing conditions contributing to the risk of Surfer’s Myelopathy. 

Design: Patients 14+ years with an SM diagnosis are enrolled in an ongoing, prospective longitudinal study. Study participation includes a detailed questionnaire on symptom development and situational exposures, clinical data, and long-term follow-up measures.

Results:

Eleven patients (10 males) ages 16-39 years (median age 23) were enrolled between 2021-2024. All patients presented during or shortly after their first surf lesson. 0/11 had heard of SM before their diagnosis or were briefed on the risk by their surf instructor. Notable findings from the history questionnaire include prolonged time spent in the prone, hyperextended position (7/10 reported prone positioning for greater than 45 consecutive minutes). Patients’ first symptom is often low back pain (7/10), and symptomatic progression to the inability to walk occurs rapidly, most often over 30-60 minutes (6/9) or within 30 minutes (3/9). In one patient, diagnostic angiography with positional examinations revealed that normal flow through a vertebral artery (supplying the anterior spinal artery craniad) disappeared in the hyperextended position.

Conclusions: The prolonged prone positioning reported by SM patients notably contrasts with techniques experienced surfers utilize. Considering that formal surf instruction was the common injury setting for all patients, incorporating preventive advice (i.e., sitting up on the surfboard while idling) into surf lessons may be the most effective strategy for reducing rates of SM.