Central pains associated with lesions of the CNS are difficult to treat.  Central pain syndromes and intractable pain provide a quagmire of evaluation and treatment components to the providers.  Central post-stroke pain (CPSP) and spinal cord injury (SCI)  are hard to manage.  Central pain occurs with spinal cord injury, MS, syringomylia, Chiari malformations, tumors or lesions of the spinal cord.  It is difficult to identify and treat central pain.  Trauma is the most common cause of SCI, estimated at 60 to  70%.  Onset of SCI pain may not occur until months after the initial injury.  It may occur below the level of the original injury, show up as  dermatomal pain or show up as pain related to cystic lesions on the spinal cord.  To complicate the process of making a diagnosis, non-SCI pain syndromes may interfere with making a diagnosis , such as radiculopathies, overuse syndromes or spasticisty. 

One of the most common central pain syndromes that occur is the brain injury response to a stroke.  Central pain post-stroke (CPSP)  occurs in about 8% of patients who have strokes.  It was first described in 1996.  Onset of pain can be anywhere from 1-2 months to 1-6 years following a stroke.  Patients describe pain in vague terms.  Sometimes, this pain is referred to as "thalamic" pain.  Patient complaints regarding thalamic pain are hard to pin down.  Hemorrhagic  and ischemic insult may affect spinal thalamic cortical pathways.  Alterations ins thalamic pathways may lead to sensitization and loss of inhibition, which results in subnormal thresholds activation of pain pathways.  Patient descriptions of pain are vague, varying form day to day.  Often patients with SCI pain complain of band-like pain, which mimics muscle pain. 

Evidence-based effective pain  relief modalities for central pain are not well documented.  Treatment options  for patients with central pain include tricyclic antidepressants, such as amitriptyline, using 50-75 mg/day doses.  Anticonvulsant medications, such as Lamotrigine, have been shown to be effective in treating SCI-related pain.    Gabapentin has been effective in reducing SCI-related pain.  Neither topiramate or carbmazepine have been shown to be effective in managing central pain.  Both DBS and spinal cord stimulation have been shown to be effective in central pain syndromes.  Botox injections have also been used for treating SCP pain.  Intrathecal analgesics have also been effective in case in which other means have been unsuccessful in controlling central pain.

Careful clinical assessment and follow-up is needed.  If you have any questions on care of patients with neuropathic pain, contact Dr. Steven Price at Steven.price@neurosciencegroup.com