A recent study was published on the characterization of transverse myelitis (TM). The researchers (including two former James T. Lubin Fellows, Drs. Sweeney and Galli) looked at data from the Veteran Health Administration’s (VHA) electronic medical records from 1999-2015. This national cohort analysis provided a modern point prevalence (meaning the number of cases in a population) of TM and stressed that the diagnosis of TM continues to be challenging for providers.
The study population consisted of all patients seeking care in the VHA system including all inpatient and outpatient visits. Then all TM cases were identified by reviewing each individual patient chart to ensure they met the diagnostic criteria for a true TM diagnosis.
961 patients out of 12,212,061 were identified with TM, including disease-related (related to multiple sclerosis, infection, or other demyelinating diseases) and idiopathic TM. The point prevalence of this group was 7.86 cases per 100,000 people, which was higher than previously reported in other studies, but was similar to the most recent county-based study in the United States. This point prevalence includes those with TM of no known cause (i.e., idiopathic) and disease-associated TM. The population of patients was 67.8% Caucasian, 18.3% African American, 3.1% Hispanic/Latino, and 2.0% Pacific Islander/Asian. Like other studies that use VHA medical records, the study population was mostly older males (90.7%) with a median age of 64.2 years.
They found that those with TM had moderate to severe deficits at the time of diagnosis. Most spinal cord lesions were in the thoracic spinal cord (42.6%), while approximately a third (35.5%) were in the cervical spinal cord, and 4.2% were in the lumbar spinal cord. The remaining TM attacks occurred in both the cervical and thoracic spinal cord. About one quarter had lesions that were longer in length than 3 vertebrae. Of the patients who had MRI reports of their brain, 17.2% of them were reported as abnormal.
68.2% of cases were diagnosed as idiopathic TM. Among all TM cases, the most common event before their diagnosis was an infection (9.7%) or vaccination (3.3%). Multiple sclerosis was the most frequent final diagnosis (16.7%). Of the 172 patients who had abnormal brain MRIs, 50.6% were eventually diagnosed with multiple sclerosis.
Spinal fluid results were available in 424 patients. An elevated protein was found in 68.4% of cases, while around half had an elevated white blood cell count. Oligoclonal bands were found in 25.6% of patients and more than half of those with oligoclonal bands had a final diagnosis of MS.
Among those for whom it was known whether they got acute treatments, 79.4% received an acute treatment. Corticosteroids were the most common treatment, and only 4.9% received plasma exchange. 71.7% of patients who received first-line immunotherapies such as corticosteroids, IVIg, or plasma exchange had some improvement in functional outcomes, and 22.6% were stable.
The authors note that their findings indicate a lack of adequate diagnostic testing: over half (57.6%) of cases did not include CSF testing and only 1/3 of cases were assigned a final diagnosis other than TM. The recent discovery of autoantibodies such as AQP-4 and MOG were not able to be included in this analysis because the study period was before there was widespread availability of this testing and it was not available at all VA centers. Also, this study was not set up to evaluate the efficacy of steroids, plasma exchange, or IVIg, so this should be looked at in future studies. However, this study does give a point prevalence using a large dataset and demonstrates the importance of prompt and accurate diagnosis at symptom onset as there is potential for intervention and prevention of disease progression.
This summary was written in part by Heather Peterson, a volunteer for the Siegel Rare Neuroimmune Association.
Original Publication: Abbatemarco J, Galli J, Sweeney M et al. Modern Look at Transverse Myelitis and Inflammatory Myelopathy: Epidemiology of the National Veterans Health Administration Population. Neurol Neuroimmunol Neuroinflamm. 2021 Aug 31;8(6):e1071.