Etiological, clinical, and radiological features of longitudinally extensive myelopathy in Chinese patients.

Longitudinally extensive myelopathy (LEM) is a rare spinal syndrome, and was mostly assessed in western populations. In order to investigate the etiological, clinical, and radiological features of LEM in Chinese patients, we retrospectively analyzed eighty-nine (40 men and 49 women, median age 45.9±15.7years) patients with LEM hospitalized in China-Japan Friendship Hospital. LEM comprised autoimmune inflammatory myelitis (n=53), metabolic and compressive disorders (n=13), vascular diseases (n=10), neoplastic diseases (n=7), infectious diseases (n=4), and syringomyelia (n=2). Neuromyelitis optica spectrum disorders (NMOSD) was the most common cause of transverse myelopathy identified in LEM (38/89 [42.7%]) characterized by intractable vomiting and hiccups and painful tonic spasms. Subacute combined degeneration and anterior spinal artery syndrome accounted for the largest non-transverse LEM, which selectively affected the spinal dorsal and/or lateral columns and the spinal anterior region, respectively. Radicular pain was common in anterior spinal artery syndrome. Postrema (n=15, 39.5%) and cervical (n=31, 81.6%) lesions were significantly increased in NMOSD versus non-NMOSD (n=7, 13.7% and n=34, 66.7%, respectively, p<0.05]. Axial T2-weighted MRI indicated that 46 (51.7%) patients exhibited complete lesions; 43 (48.3%) patients exhibited non-transverse lesions, mainly unilateral or symmetrical tract lesions. Twenty-four (51.1%) LEM patients exhibited distinct gadolinium contrast enhancement. In this Chinese cohort, LEM was primarily attributed to NMOSD. While the etiological distribution in the non-NMOSD group was different from western populations, clinical and imaging features may facilitate a differential diagnosis.