Flexed neck posture due to cervical posttraumatic syringomyelia

A flexed neck posture, especially with prolonged sitting, developed in three quadriplegic patients as a manifestation of posttraumatic syringomyelia (PTS). This posture developed at 1, 6, and 20 years after spinal cord injury. All patients complained of increasing weakness of the neck with several hours of sitting, and all required analgesics for aching neck pain. Neck weakness preceded an ascent of the level of sensory or motor deficit in two patients, and followed it in one. Current muscle testing failed to demonstrate weakness of neck extension in any patients, but electromography revealed chronic denervation and reinervation of cervical paraspinal muscles in each patient. Magnetic resonance imaging revealed a syrinx extending from the site of injury to the medulla oblongata in each case. We conclude that a flexed neck posture can represent: (1) a loss of stamina in denervated head support musculature, (2) either a precursor or successor to the conventional signs of PTS, and (3) high cervical syringomyelia.