Abnormal Spinal Cord Magnetic Resonance Signal: Approach to the Differential Diagnosis

Epidemiology of non-traumatic spinal cord injury in Uganda: a single center, prospective study with MRI evaluation

BACKGROUND

A few reliable national data concerning the etiology of non-traumatic spinal cord injury (SCI) in sub-Sahara Africa exists, mainly because of the limitations of diagnostic imaging. These are both expensive and mostly unavailable in several resource-limited settings. Only a few studies have employed the magnetic resonance imaging (MRI) in documenting non-traumatic SCI and most of these studies are from South Africa. We sought to describe the clinical presentation, MRI radiological patterns, and one-year survival among subjects with non-traumatic SCI in Uganda.

METHODS

We enrolled a prospective cohort of 103 participants with non-traumatic SCI at Mulago National Referral Hospital Kampala, Uganda in 2013-2015. Participants received standard of care management, with surgical intervention as needed, with one-year follow up. Data were analyzed using Descriptive statistics.

RESULTS

In 103 participants with non-traumatic SCI, the median (IQR) age was 37 (18, 85) years and 25% of the participants were HIV-infected. Paraplegia/paraparesis was the most common clinical presentation in 70% (n = 72). Severe disease was present in 82% (n = 85) as per American Spinal Injury Association (ASIA) scale A-C. On MRI, 50% had extradural lesions. However, bone lesions accounted for only 75% of all the extradural lesions. More than 60% of the patients had lesions that could only be diagnosed on MRI. Deaths occurred in 42% (n = 44) of participants, with the highest mortality among those with extradural lesions (60%).

CONCLUSION

The mortality following non-traumatic spinal cord injuries in Uganda is high. We demonstrated an equal distribution between extradural and intradural lesions, which differs from the historical predominance of extradural lesions. Increased utilization of MRI particularly among young age groups is needed to make a diagnosis.

Progressive Fatal Myelopathy Secondary to Isolated Spinal Cord Vasculitis

A 56-year-old woman with various neurological signs which developed over a 1-year period was admitted for evaluation. MRI showed a markedly abnormal signal in the cervical spine. Despite treatment with IV steroids, she developed a progressive myelopathy, became quadriplegic, and required intubation. Immunomodulatory treatment was ineffective. The patient died 24 days after admission. Histopathological investigation revealed spinal cord necrosis with a lymphocyte predominant meningovascular inflammation involving arteries and veins along with evidence of prior occlusive disease of the anterior spinal artery. The changes were confined to the spinal cord. The present case represents an unusual cause of myelitis for which early and aggressive immunomodulatory treatment may have influenced outcomes.

Magnetic Resonance Imaging and Clinical Features in Acute and Subacute Myelopathies

Differential diagnosis of acute and subacute transverse myelopathy includes inflammatory, infectious, vascular, metabolic and paraneoplastic etiologies. Information on the diagnostic approach to transverse myelopathy with regard to daily clinical practice is provided. The differentiation between five lesion patterns on magnetic resonance imaging (MRI) in myelitis may be helpful: (1) longitudinal extensive transverse myelitis, (2) short segment ovoid or peripherally located, (3) "polio-like", (4) granulomatous and (5) segmental with rash. A correlation with these imaging features is supported if the clinical course and neurological symptoms are known. Although the mean interval from onset to nadir of symptoms in spinal cord infarction is 1 h, an overlap with a fulminant course of myelitis is possible, and impaired diffusion may also occur in acute inflammatory processes. As a result, laboratory testing, including aquaporin-4 antibodies and cerebrospinal fluid analysis, is crucial for the correct interpretation of imaging findings. Moreover, the discrimination of acute complete and acute partial transverse myelitis is advantageous in order to identify diverse entities, the latter often being a precursor to multiple sclerosis. Additional brain imaging is mandatory in suspected demyelinating, infectious, neoplastic and systemic autoimmune disease. A symmetrical lesion pattern restricted to individual tracts or dorsal columns indicates subacute combined degeneration of the spinal cord and, in addition to deficiency syndromes, a paraneoplastic etiology should be considered.