Pseudogout-Induced Cervical Myelopathy: A Report of Two Cases and Review of the Literature.

Calcium pyrophosphate dihydrate deposition (CPPD) disease, also known as pseudogout, is the most common cause of calcification of ligamentum flavum (CLF) compared to other degenerative conditions. Symptomatic CLF is a rare cervical spine disorder that leads to spinal cord compression, resulting in myelopathic symptoms. We report two rare cases of pseudogout-induced cervical myelopathy, along with a review of the literature. Both patients were seen at Al-Azhar University Hospital in Cairo, Egypt, presenting with severe neck pain, gait disturbances, and hand clumsiness. The first patient had these symptoms for two months, while the second patient experienced them for three months. The second patient also had restricted motion in extension and rotation, as well as shooting pain in both upper extremities. Cervical spine MRI revealed posterior cord compression and myelomalacia at the C3-C6 levels in the first patient and at the C4-C5 levels in the second patient. Pseudogout (CPPD) disease was suspected as the cause of spinal cord compression, and histopathological analysis of the deposits found at the site of compression during the decompression procedure confirmed the diagnosis. The deposits were characterized by rhomboid blue calcium crystals that were mildly birefringent, distinguishing them from the needle-shaped crystals seen in gout. At the four-week postoperative follow-up, both patients showed significant improvement in clinical and functional outcomes, as measured by the Japanese Orthopaedic Association score. In summary, CLF due to pseudogout (CPPD deposition) is a rare but clinically significant cause of cervical myelopathy. Histopathological examination is crucial for a definitive diagnosis. Early posterior cervical decompression with instrumentation appears to be an effective treatment, though larger studies and long-term follow-up are necessary to confirm these findings and optimize management strategies.