MRI-negative myelopathies refer to spinal cord dysfunctions where the cause cannot be identified through magnetic resonance imaging (MRI). While MRI is a powerful diagnostic tool, it may not detect certain conditions that can cause myelopathy. Some potential causes of MRI-negative myelopathies include:
- Vascular disorders: Spinal cord ischemia, arteriovenous malformations, or dural arteriovenous fistulas may not be easily visible on a standard MRI.
- Inflammatory or autoimmune conditions: Conditions such as neurosarcoidosis, neuromyelitis optica spectrum disorders, or multiple sclerosis might not always show typical lesions on an MRI.
- Infectious causes: Spinal cord infections, such as viral myelitis, bacterial or fungal infections, may not be easily detected on MRI.
- Metabolic or nutritional disorders: Vitamin B12 deficiency or copper deficiency can lead to myelopathy, but these may not be visible on MRI.
- Genetic or hereditary conditions: Conditions like adrenomyeloneuropathy, hereditary spastic paraplegia, or spinocerebellar ataxias may not always be detected through imaging.
- Functional neurological disorders: These disorders involve abnormal nervous system functioning without visible structural damage, and they can mimic myelopathy.
- Paraneoplastic syndromes: These rare neurological syndromes can occur as a result of an immune response to cancer and might cause myelopathy without MRI-visible lesions.
- Transverse myelitis: In the early stages of this inflammatory spinal cord disorder, MRI findings might be inconclusive or negative.
- Traumatic or mechanical causes: Subtle spinal cord trauma or mechanical compression may not be evident on MRI, particularly if the images are not taken in specific positions.
