Longitudinally extensive transverse myelitis: A retrospective analysis of sixty-four patients at tertiary care center of North-West India.

OBJECTIVES: To evaluate the demographic profile, clinical presentations, laboratory parameters and etiologies of longitudinally extensive transverse myelitis (LETM) patients in Indian population.

PATIENTS AND METHODS: LETM is characterized by contiguous inflammatory lesions of spinal cord extending to three or more vertebral segments. Neuromyelitis optica (NMO) is the most common cause of LETM. In clinical practice, both LETM and NMO are thought to be synonymous with each other because of their very frequent association. Other causes of LETM are infective, neoplastic, autoimmune diseases and connective tissue disorders. All other causes should be ruled out before making the diagnosis of NMO in LETM patients. We conducted a retrospective study from August 2010 to February 2016 and analyzed various demographic profile, clinical presentations, laboratory parameters and etiologies in sixty-four patients of LETM.

RESULTS: In our series, majority of the patients presented with acute bladder dysfunction and paraparesis. Twenty-one patients (32.81%) were clinically diagnosed as NMO, out of which thirteen patients were found to have positive serum NMO antibody. Other etiologies of LETM in our series were multiple sclerosis [9 patients], acute disseminated encephalomyelitis (ADEM) [6 patients], postinfectious [5 patient], subacute combined degeneration (SCD) [4 patient], tuberculous myelitis [4 patients], spinal arteriovenous malformation (AVM) [3 patient] and systemic lupus erythematosus (SLE) [3 patient], respectively. In nine patients, cause could not be ascribed despite thorough investigations.

CONCLUSION: LETM is a heterogeneous disorder with a varied clinical feature, etiologies and outcome. Even the LETM patients who presented with optic neuritis do not necessarily have NMO. Therefore, the diagnosis of NMO should be made only after excluding other causes of LETM. The presence of NMO-Ab (Aquaporin 4-Ab) predicts the increased risk of recurrence of LETM or conversion to NMO.