Central pain syndrome

Overview

Central pain syndrome (CPS) is a neurological condition caused by damage to the central nervous system (CNS), which includes the brain, brainstem, and spinal cord. This damage disrupts how pain signals are processed, resulting in chronic pain that can vary in intensity and character. CPS can develop after a stroke, multiple sclerosis, brain injury, or spinal cord injury. The pain is often constant and may be triggered or worsened by touch, movement, temperature changes, or even emotional stress. CPS can be severely debilitating and difficult to treat.

Causes

Central pain syndrome arises from injury or dysfunction within the CNS. Common causes include:

• Stroke: Particularly thalamic stroke, which affects the brain’s sensory processing center

• Multiple sclerosis (MS): A demyelinating disease that affects nerve signal transmission

• Traumatic brain injury (TBI): Leading to abnormal pain perception

• Spinal cord injury: Disrupts pain pathways and can lead to CPS below the site of injury

• Brain tumors, infections, or surgeries: That affect sensory pathways in the CNS

Symptoms

Symptoms of central pain syndrome can vary based on the site and extent of CNS damage. Common features include:

• Chronic pain: Often described as burning, aching, stabbing, or electric shock-like

• Abnormal sensations: Such as tingling, numbness, or hypersensitivity (allodynia)

• Pain exacerbated by: Light touch, movement, stress, cold or heat

• Distribution: Pain may be localized or widespread, often affecting one side of the body or below the level of a spinal cord lesion

• Sleep disturbances, fatigue, and mood changes: Due to persistent pain

The pain in CPS is typically continuous and may significantly interfere with daily functioning and quality of life.

Diagnosis

Diagnosing central pain syndrome involves a detailed medical history, clinical examination, and exclusion of other causes of chronic pain. Diagnostic steps may include:

• Neurological examination: To assess sensory deficits and pain distribution

• Imaging studies: MRI or CT scans to identify structural lesions in the brain or spinal cord

• Electrophysiological tests: Such as somatosensory evoked potentials (SSEPs) to assess nerve signal pathways

• Pain questionnaires: To evaluate the nature and impact of the pain

• Rule out other conditions: Such as peripheral neuropathy, fibromyalgia, or musculoskeletal disorders

Treatment

Central pain syndrome is challenging to treat, and complete pain relief is rare. However, a combination of therapies can help reduce symptoms and improve function. Common treatments include:

• Medications:

  • Antidepressants: Such as amitriptyline or duloxetine, which can modulate pain perception

  • Anticonvulsants: Like gabapentin or pregabalin, commonly used for neuropathic pain

  • Pain relievers: NSAIDs may provide limited benefit; opioids are usually avoided due to limited efficacy and risk of dependence

• Physical therapy: To maintain mobility and reduce stiffness

• Cognitive behavioral therapy (CBT): Helps patients cope with chronic pain and associated emotional distress

• Occupational therapy: For adaptive strategies and improving daily function

• Transcranial magnetic stimulation (TMS) or spinal cord stimulation: May be used in select refractory cases

Prognosis

The prognosis for individuals with central pain syndrome varies. While the condition is usually chronic and persistent, symptom severity may fluctuate over time. Many patients experience partial relief with multimodal treatment approaches, though pain often remains a long-term issue. Early diagnosis, consistent management, and a supportive care team can improve daily functioning and quality of life. Psychological support is crucial, as chronic pain is often associated with depression, anxiety, and social isolation.