Pain in Guillain-Barre syndrome
Pain in Guillain-Barre syndrome (acute inflammatory demyelinating polyradiculo-neuropathy) develops in 89% of patients. Clinically, with this disease, there are 2 types of pain. The first type is aching pain in the back and legs, the severity of which correlates with muscle weakness. The pain can be localized in the gluteal region, along the front and back surfaces of the hips from 2 sides. Passive movements in the affected muscles contribute to increased pain. The second type is persistent burning pain accompanied by paresthesias and hyperesthesia. The first type of pain is probably associated with inflammation and compression of the nerve roots, the second - with a violation of the function of demyelinated sensory nerves and the appearance in them of spontaneous discharges. Nevertheless, the pathophysiological mechanisms of pain in the Guillain-Barre syndrome have not yet been adequately studied. There is a suggestion that due to demyelination of thick (well myelinated) and thin (poorly myelinated) sensory fibers, the physiological balance between the nociceptive (via thin fibers) and antinociceptive (by thick fibers) entering impulses into the horn is disturbed. These mechanisms partially explain the low effectiveness of NSAIDs and opioids in patients with Guillain-Barre syndrome. That's why in the treatment of pain in the Guillain-Barre syndrome began to use anticonvulsants. In 2 short randomized trials, gabapentin was evaluated in the acute stage of the disease compared with placebo and carbamazepine, as well as with the use of opioids on demand. In one study, gabapentin was more effective than placebo and reduced the frequency of opioid use. In another study, a higher efficacy of gabapentin compared with carbamazepine was established.
Based on a systematic analysis of pain management data for Guillain-Barre syndrome, it was suggested that carbamazepine or gabapentin should be used in the acute stage of the disease to relieve pain. The use of opioids should be limited due to the side effects that are particularly common in patients with Guillain-Barre syndrome (probably due to a violation of autonomic innervation typical of this disease).