Syringomyelia: a rare extracardiac contributor to syncope detected incidentally by CMR

We describe an extracardiac finding of syringomyelia in CMR study of a patient who was being investigated to exclude an infiltrative cause for presumptive cardiogenic syncope. Extension of a syrinx to involve the sympathetic structures in the intermediolateral column of the spinal cord can lead to well-recognised autonomic disturbances including Horner's syndrome. Autonomic control of the heart has also been shown to be impaired in patients with syringomyelia. We investigated a 20 year old man presented with a history of recurrent syncope triggered by pain, micturition and defaecation. The cardiac MRI findings were normal, however close inspection of the scout images was suggestive of a lower thoracic spinal cord syrinx - a finding later confirmed by dedicated spinal MRI. Subsequent neurological investigations were essentially normal. We suggest that syringomyelia-induced disruption of sympathetic fibres in the thoracic spinal cord is a plausible, but rare mechanism of syncope.