What are the potential causes and treatment options for numbness in the torso?

Numbness in the Torso: Causes and Management

Torso numbness requires immediate evaluation for spinal cord injury or compression, as these represent medical emergencies where delayed recognition can result in permanent paralysis and loss of bowel/bladder function.

Immediate Life-Threatening Causes to Rule Out

Spinal Cord Injury

• Suspect spinal injury if the patient has any of the following risk factors: age ≥65 years, motor vehicle/bicycle crash, fall from greater than standing height, sensory deficit or muscle weakness involving the torso or upper extremities, not fully alert or intoxicated, or other painful injuries especially of the head and neck 1
• Sensory deficit or muscle weakness involving the torso is a specific red flag that mandates spinal motion restriction by manually stabilizing the head to minimize motion of head, neck, and spine 1
• Do not use immobilization devices unless properly trained, as they may be harmful 1
• Immediate MRI of the entire spine is necessary to exclude cord compression or transverse myelitis in patients with torso numbness and any neurological signs 2

Thoracic Outlet Syndrome (TOS)

• TOS occurs with compression of the brachial plexus, subclavian artery, and/or subclavian vein at the superior thoracic outlet, which can present with neurological symptoms including chronic arm and hand paresthesia, numbness, or weakness 1
• Neurological symptoms from TOS may extend to the torso in severe cases, particularly when the costoclavicular space or interscalene triangle is narrowed 1
• Risk factors include repetitive upper-extremity movement (swimming, throwing) or anatomical variants such as cervical rib, anomalous first rib, or post-traumatic changes from prior clavicular or rib fractures 1

Diagnostic Approach

Initial Assessment

• Assess the distribution pattern: dermatomal (suggests radiculopathy), bilateral symmetric (suggests peripheral neuropathy or myelopathy), or unilateral (suggests stroke, plexopathy, or focal nerve injury) 3
• Determine time course: acute onset (<48 hours) versus subacute/chronic progression 3
• Check for associated symptoms: weakness, bowel/bladder dysfunction, pain, or autonomic changes 1, 2

Red Flags Requiring Emergency Imaging

• Progressive motor weakness or sensory loss indicates evolving myelopathy or Guillain-Barré syndrome requiring immediate imaging and specialist evaluation 4
• Bilateral lower extremity symptoms with perineal numbness suggests cauda equina syndrome requiring emergency MRI 5
• Assess for areflexia/hyporeflexia, ascending weakness pattern, and preceding infection within 6 weeks (Guillain-Barré syndrome) 2

Imaging Studies

• MRI of the entire spine with and without contrast is the gold standard for evaluating spinal cord compression, transverse myelitis, or structural abnormalities 2
• CT imaging may be used if MRI is contraindicated, though it is less sensitive for soft tissue and cord pathology 3
• Imaging allows differentiation of edema and inflammation from gliosis and atrophy, and can detect compression of nervous system structures 3

Common Non-Emergency Causes

Peripheral Neuropathy

• Diabetic neuropathy typically presents with symmetric "stocking-glove" distribution affecting distal extremities first, but can extend proximally to involve the torso in severe cases 1
• Check fasting blood glucose and HbA1c to screen for diabetes 2
• Order serum protein electrophoresis with immunofixation to detect monoclonal gammopathy 2
• Vitamin B12 deficiency can cause peripheral neuropathy; check B12 levels and replace if deficient 2

Chemotherapy-Induced Peripheral Neuropathy (CIPN)

• Occurs in 30-40% of patients treated with taxane-based or platinum-based chemotherapy regimens 1
• Presents with bilateral and symmetrical sensory disorders including numbness, tingling, and burning pain that initially affects the toes and fingers, and may extend proximally 1
• Electrophysiological studies show length-dependent axonal neuropathy with 50% decrease in sensory nerve action potential amplitude 1

Radiculopathy

• Cervical or thoracic radiculopathy presents with dermatomal pattern of sensory loss, may have associated motor weakness or reflex changes 4
• Differs from peripheral neuropathy which shows symmetric distribution 4

Treatment Based on Diagnosis

Spinal Cord Injury/Compression

• Maintain spinal motion restriction until definitive imaging excludes injury 1
• Emergency neurosurgical consultation for cord compression requiring decompression 2
• Admit to monitored setting with respiratory monitoring capability if Guillain-Barré syndrome suspected 2

Peripheral Neuropathy Management

• For diabetic neuropathy: Target HbA1c <7% to prevent progression 2
• First-line medications for painful neuropathy: duloxetine, gabapentin, or pregabalin 1, 2
• Physical activity has been shown to improve neuropathy symptoms 1
• Duloxetine 30 mg daily for first week (to reduce nausea), then increase to 60 mg daily, provides 30-50% pain reduction 1

Thoracic Outlet Syndrome

• Conservative management initially with physical therapy and activity modification 1
• Surgical decompression may be required for refractory cases or vascular complications 1

Follow-Up and Monitoring

• Schedule reassessment in 2-4 weeks to review laboratory results, assess response to initial interventions, and determine need for specialist referral 2
• Monitor for progression of symptoms and adjust treatment as needed 2
• Refer to neurology for progressive symptoms, unclear diagnosis, or inadequate response to initial management 2