Diffuse Idiopathic Skeletal Hyperostosis Presenting as Cervical Radiculopathy in Metabolic Syndrome: A Case Report
Jacob Oliver, Odiaka Anombem, George Zeng, Robert Tompkins, Tonya Youngblood, Steven Griffin, Christian FerrerBackground
DISH is common. It affects about 12% of the general population and a quarter of men over 50. The pathophysiology is metabolic. Circulating insulin phosphorylates IRS-1 in osteoblasts at entheseal insertion points, which activates PI3K/Akt and MAPK cascades and ultimately drives ectopic bone formation along spinal ligaments. Once enough of the spine has fused, the whole column behaves as a long bone. It can no longer dissipate force across mobile segments. Harlianto et al. reported vertebral fractures in 22.6% of DISH patients compared with 15.2% in ankylosing spondylitis, and Caron et al. reported 51% mortality with conservative fracture management versus 23% with surgery. Despite these numbers, primary care physicians rarely consider the diagnosis.
Case
We treated a man in his fifties who woke from sleeping in a chair with severe posterior cervical pain in a C2-C3 distribution, radiating to the left ear and scalp. His history was notable for uncontrolled type 2 diabetes (hemoglobin A1c 9.2%), class I obesity, coronary artery disease, and paroxysmal atrial fibrillation. On examination he had posterior cervical rigidity and suboccipital tenderness. Neurologic examination was normal. Lateral cervical films showed flowing anterior osteophytes from C3 through C7 with preserved disc spaces, facet hypertrophy at C4-C5 and C5-C6, and no fracture. We prescribed gabapentin and methocarbamol, sent him to physical therapy with orders to avoid manipulation, and spent time on fracture risk education. His pain went from 10/10 to 3/10 over two weeks.
Conclusions
DISH can look like cervical radiculopathy, occipital neuralgia, or simple mechanical neck pain. The same hyperinsulinemia that produces hepatic steatosis and accelerates atherosclerosis also drives pathologic bone formation at spinal entheses. A lateral cervical radiograph is all that is needed for diagnosis. Flowing anterior osteophytes with preserved disc spaces look nothing like the syndesmophytes of ankylosing spondylitis or the irregular osteophytes of degenerative spondylosis. What matters most clinically is the fracture risk. These patients have a rigid spine that cannot absorb force from even a minor fall. In rural practice, where a neurosurgeon may be hours away, identifying DISH and teaching the patient when to go to an emergency department may be the most important thing we do for them.