Summary
Central neuropathic pain (CNP) is a type of chronic pain that arises directly from a central nervous system (CNS) lesion. The most common causes of CNP are stroke, spinal cord injury, and multiple sclerosis. CNP is characterized by spinothalamic tract dysfunction with neuropathic pain in the region of the body affected by the CNS lesion. Symptoms may not manifest for months or even years after the neurological insult. Diagnosis is based on history, characteristic clinical features, and a lesion identified on neuroimaging that aligns with the observed pattern of central neuropathic pain. Although complete symptom resolution is unlikely, multimodal pain management (e.g., both nonpharmacological pain management and pharmacological therapy) can improve functionality and reduce pain.
Etiology
- Common causes
-
Other causes
- Malignancy (e.g., brain tumor)
- Neuroinflammatory conditions (e.g., brain abscess, encephalitis)
- Head trauma
Clinical features
Description of pain [1][2]
- A combination of spontaneous (continuous or paroxysmal) and evoked pain (e.g., allodynia).
- Neuropathic pain and dysesthesia
- Pain may be more intense in the distal regions of the affected areas, particularly in stroke-related CNP.
The onset of CNP is generally months or years after a neurological insult. [1]
Patients will also have clinical features of the underlying neurological condition. [1]
Patterns of pain distribution [1][2]
CNP always manifests with spinothalamic tract dysfunction (i.e., loss of pinprick sensation and temperature sensation) in the regions affected by a neurological insult. [1]
| Patterns of central neuropathic pain | |
|---|---|
| Underlying neurological insult | Location of spinothalamic dysfunction and pain |
| Stroke and/or brainstem lesion |
|
| Thoracic spinal cord injury |
|
| Multiple sclerosis |
|
Spinothalamic tract dysfunction with neuropathic pain in the regions of the body affected by the neurological insult is the hallmark of CNP. [1]
CNP may not be present in the entire neurologically affected region. [1]
Diagnosis
Perform a clinical evaluation, obtain neuroimaging, and assess whether diagnostic criteria for central neuropathic pain are met.
Clinical evaluation [1][2][3]
- Assess for history or findings of a prior neurological insult. [1]
- Perform a comprehensive neurological examination and pain assessment.
- Consider the use of screening tools to help distinguish neuropathic pain from other types of pain.
- DN4 questionnaire [2]
- Neuropathic pain questionnaire (NPQ) [1][4]
- Leeds assessment of neuropathic symptoms and signs (LANSS) [5]
Imaging [2]
- Imaging is required to assess for and locate neurological lesions.
- Modality: CT or MRI, depending on the suspected neurological condition
Diagnostic criteria for central neuropathic pain [3][6][7]
- History consistent with an underlying CNS pathology
- Neuropathic pain that is consistent with an expected pattern of central neuropathic pain
- A lesion identified on neuroimaging that aligns with the observed symptom distribution
Distinguishing between CNP and other types of pain in patients with neurological impairment is challenging. For diagnostic uncertainty, refer patients to neurology. [1]
If spinothalamic function is normal in the region that would be affected by an identified CNS lesion, consider alternative diagnoses. [1]
Differential diagnoses
- Musculoskeletal pain
- Spasticity
- Peripheral neuropathy (e.g., radiculopathy, postherpetic neuralgia)
- Central sensitization
The differential diagnoses listed here are not exhaustive.
Treatment
A complete resolution of pain is unlikely. Individualized treatment should focus on reducing pain to a manageable level.
- Multidisciplinary involvement, e.g., with neurology, neurosurgery, physical therapy, psychology, and/or pain specialists
-
Multimodal pain management (see also “Chronic noncancer pain management”)
- Patient education on chronic pain management, including establishing appropriate expectations
-
Nonpharmacological pain management, e.g.,
- CBT, biofeedback training
- Neuromodulation (e.g., with spinal cord stimulation) for refractory symptoms
- Pharmacological analgesia (titrated to symptom response)
- TCAs (e.g., amitriptyline)
- SNRIs (e.g., duloxetine)
- Anticonvulsants (e.g., pregabalin, gabapentin)
- Management of other causes of pain, e.g., spasticity with multiple sclerosis