Etiology and Factors Related Outcomes of Longitudinally Extensive Transverse Myelitis in Thailand

Objective This study aimed to evaluate the clinical features, etiology, and prognosis of longitudinally extensive transverse myelitis (LETM) patients in Thailand.

Background LETM has various etiology and is different in each region. Proper investigations are essential to reduce misdiagnosis and delay in treatments, which affect clinical recovery and prognosis. In Thailand, there is no clinical study on the etiology of LETM. Therefore, our study aimed to evaluate the clinical features, etiology, and prognosis of LETM patients in Thailand.

Design/Methods Patients diagnosed with LETM at University Hospital between January 2015 and October 2021 were included. Patient demographics, clinical presentations, Expanded Disability Status Scale (EDSS), imagings, laboratory testing, cerebrospinal fluid profiles, final diagnosis, and treatments were recorded. Factors related to outcomes of LETM were analyzed.

Results A total of 40 patients, there were 21 females (52.5%), the mean age of onset was 48.4 years (SD = 15.8). NMOSD was the most common etiology of LETM (n = 15), followed by infection (n = 5), SLE (n = 5), idiopathic causes (n = 4), CIS (n = 3), MS (n = 1), spinal dural AVF (n = 2), ADEM (n = 2), either 1 had spinal cord infarction, schwannoma, and vitamin B12 deficiency. Most patients in this study had severe LETM (n = 31). Complete cord had significantly poorer outcome (p-value = 0.003), while dorsolateral and anterior cord had better outcome (p-value = 0.046, 0.046).

Conclusions NMOSD was the most common etiology of LETM, and a history of prior attacks led to the diagnosis of NMOSD. Complete cord lesion on axial spinal cord MRI was sensitive to NMOSD but not specifically. Factors related to the prognosis of LETM included completed cord lesions on MRI axial view trended to have a poor outcome, and dorsolateral and anterior cord lesions had a better prognosis.