Band-like sensory disturbance around the trunk is characteristic of which myelopathy, and if non‑compressive what is the usual cause?

Band-Like Sensation in Myelopathy

A band-like sensory disturbance around the trunk is characteristic of thoracic myelopathy, and when non-compressive, the most common causes are demyelinating diseases (particularly multiple sclerosis), spinal cord ischemia, or metabolic myelopathies such as vitamin B12 deficiency. 1, 2

Anatomical Localization

• Band-like sensations (also called sensory levels) typically indicate thoracic spinal cord pathology, as the dermatomal distribution creates a circumferential pattern around the trunk 3
• The sensory level corresponds to the highest level of spinal cord dysfunction, though false localizing sensory levels can occur 4
• Cervical myelopathy can paradoxically present with thoracic sensory levels (T4-T10), creating diagnostic confusion and potentially delaying appropriate treatment 4

Critical Pitfall

• Do not assume a thoracic sensory level always indicates thoracic cord pathology - cervical compression can produce false localizing thoracic sensory levels in up to 4 documented cases, with persistence of these levels even after successful cervical decompression surgery 4
• Always image the cervical spine with MRI even when clinical examination suggests a thoracic level 4

Non-Compressive Causes

Demyelinating Disease (Most Common Non-Compressive Etiology)

• Multiple sclerosis involves the spinal cord in 80-90% of patients, most commonly affecting the cervical cord, though thoracic involvement produces the classic band-like sensation 1, 2
• MS spinal cord lesions are typically small (≤2 vertebral segments), peripherally located in lateral and posterior columns, and wedge-shaped on axial imaging 1
• Neuromyelitis optica (NMO) causes longitudinally extensive transverse myelitis (≥3 vertebral segments) with cloud-like enhancement patterns, distinguishing it from MS 1, 2

Vascular Causes

• Spinal cord ischemia results from atheromatous disease, aortic surgery complications, systemic hypotension, or fibrocartilaginous embolic disease 2
• Spinal arteriovenous malformations cause progressive myelopathy through venous hypertension, with characteristic dorsal cord edema and enlarged veins 1, 2

Metabolic Causes

• Vitamin B12 deficiency produces subacute combined degeneration with characteristic posterior and lateral column involvement 1, 2, 3
• Copper deficiency myelopathy presents similarly to B12 deficiency 2, 3

Infectious Causes

• Human T-cell lymphotropic virus myelitis, tuberculosis, HIV vacuolar myelopathy, and schistosomiasis can all produce non-compressive myelopathy with band-like sensations 1, 2, 3

Diagnostic Approach

• MRI without and with IV contrast is essential to distinguish compressive from non-compressive etiologies and evaluate for inflammatory, infectious, or neoplastic causes 1, 3
• Contrast enhancement patterns help differentiate etiologies: pancake-like enhancement suggests spondylotic myelopathy 1, 5, cloud-like enhancement suggests NMO 1, and band-like enhancement suggests Balo concentric sclerosis 1
• Diffusion-weighted imaging should be included when spinal cord ischemia is suspected, as it shows signal changes earlier than T2-weighted sequences 1

Imaging Characteristics by Etiology

• MS lesions: Small, focal, peripherally located, wedge-shaped on axial views 1
• NMO lesions: Longitudinally extensive (≥3 segments), central gray matter involvement, cloud-like enhancement 1
• Metabolic myelopathy: Posterior and lateral column T2 hyperintensity without enhancement 1
• Ischemic myelopathy: Central gray matter involvement (owl's eyes sign), restricted diffusion 1