What is transverse myelopathy syndrome?

What is Transverse Myelitis?

Transverse myelitis is an acute inflammatory disorder of the spinal cord characterized by rapid onset of bilateral motor weakness, sensory disturbances, and autonomic dysfunction that typically progresses to maximal severity within 10 days of symptom onset. 1, 2, 3

Clinical Presentation

The syndrome manifests with a distinctive triad of neurological deficits:

• Motor dysfunction: Patients develop spastic paralysis with increased deep tendon reflexes (hyperreflexia) due to upper motor neuron damage, not flaccid paralysis. At peak deficit, approximately 50% of patients become completely paraplegic with no volitional leg movements. 2, 3, 4

• Sensory alterations: Between 80-94% of patients experience numbness, paresthesias, or band-like dysesthesias. Sensory disturbances are typically bilateral and progress over hours to days. 3, 4

• Autonomic dysfunction: Virtually all patients develop some degree of bladder dysfunction, often accompanied by bowel dysfunction and urinary retention. 2, 3, 4

Pathophysiology

The condition results from perivascular monocytic and lymphocytic infiltration of the spinal cord, leading to demyelination and axonal injury. 4 The inflammatory process affects spinal cord gray matter, causing upper motor neuron damage that explains the characteristic spastic paralysis with hyperreflexia rather than the flaccid paralysis seen in peripheral nerve disorders like Guillain-Barré syndrome. 2

Etiologic Categories

Transverse myelitis exists along a spectrum from idiopathic to disease-associated forms:

• Demyelinating diseases: Multiple sclerosis (80-90% have spinal cord involvement), neuromyelitis optica spectrum disorder (especially when ≥3 vertebral segments involved), and acute disseminated encephalomyelitis (25% have spinal involvement). 1, 2

• Infectious causes: HIV, cytomegalovirus, Epstein-Barr virus, varicella zoster virus, syphilis, tuberculosis, diphtheria, schistosomiasis, and enterovirus infections. 1

• Autoimmune/inflammatory conditions: Systemic lupus erythematosus, Sjögren syndrome, mixed connective tissue disorder, Behçet disease, sarcoidosis, and antiphospholipid antibody syndrome. 1, 5

• Drug-induced: Immune checkpoint inhibitors, intrathecal chemotherapy (methotrexate, cytarabine, cisplatin), and high-dose systemic chemotherapy. 1

• Vascular: Spinal cord ischemia affecting the anterior spinal artery territory. 1

• Idiopathic: Despite extensive workup, many cases remain without identified cause. 3, 5, 6

Diagnostic Approach

MRI of the spine with and without contrast is the reference standard imaging modality, showing T2-weighted hyperintense lesions that appear wedge-shaped on axial views and cigar-shaped on sagittal views. 1, 2, 3 However, approximately 40% of cases show no MRI abnormalities despite clinical presentation. 5

Essential diagnostic workup includes:

• Neurologic consultation immediately upon presentation. 1, 2

• MRI spine with thin axial cuts through suspected abnormality regions, with and without IV contrast. Diffusion-weighted imaging should be included when spinal cord ischemia is suspected. 1, 2

• Lumbar puncture: Cell count, protein, glucose, oligoclonal bands, viral PCRs (HSV, CMV, EBV, VZV), cytology, and onconeural antibodies. Elevated CSF interleukin-6 levels strongly correlate with and predict disability severity. 1, 2, 4

• Blood tests: B12, HIV, RPR (syphilis), ANA, Ro/La antibodies, TSH, aquaporin-4 IgG (for neuromyelitis optica), thyroid peroxidase, CBC, ESR, CRP, and ANCA if vasculitis suspected. 1, 2

• Brain MRI to evaluate for disseminated lesions suggesting multiple sclerosis or other systemic demyelinating conditions. 1

Management Strategy

Permanently discontinue any potentially causative agent (immune checkpoint inhibitors, intrathecal chemotherapy) and initiate high-dose corticosteroids immediately. 1, 2

Treatment algorithm by severity:

• Grade 1 (mild): Methylprednisolone 2 mg/kg daily. 1, 2

• Grade 2 (moderate): Strongly consider pulse-dose methylprednisolone 1 g IV daily for 3-5 days. Strongly consider adding IVIG 2 g/kg over 5 days. 1, 2

• Grade 3-4 (severe): Methylprednisolone 1 g IV daily for 3-5 days plus IVIG 2 g/kg over 5 days. If limited improvement or positive autoimmune antibodies, consider plasma exchange or rituximab. 1, 2

For drug-induced cases (particularly immune checkpoint inhibitors), start dexamethasone one day before any anthelmintic treatment if parasitic etiology suspected, with longer corticosteroid courses if marked edema on imaging or clinical deterioration occurs. 1

Prognosis

Recovery is divided approximately equally into three groups: one-third recover with minimal or no sequelae, one-third have moderate permanent disability, and one-third have severe disability. 3, 4 The time period and degree of recovery is highly variable, ranging from weeks to months. 7, 6

Critical Distinguishing Features

The presence of increased deep tendon reflexes (spastic paralysis) distinguishes transverse myelitis from conditions causing flaccid paralysis such as Guillain-Barré syndrome (reduced/absent reflexes from peripheral nerve involvement) or poliomyelitis (flaccid paralysis from anterior horn cell damage). 1, 2 This clinical finding is essential for narrowing the differential diagnosis and guiding appropriate management.