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

• Less than 50% of our adult cohort had NMO.
• Patients with LETM require a thorough workup to exclude treatable causes.
• The management of LETM depends on specific etiology.
• In rare instances tuberculosis can cause LETM.
• NMO-Ab predicts the increased risk of recurrence in LETM or conversion to NMO.

ObjectivesTo evaluate the demographic profile, clinical presentations, laboratory parameters and etiologies of longitudinally extensive transverse myelitis (LETM) patients in Indian population.Patients and methodsLETM 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.ResultsIn 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.ConclusionLETM 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.