Multiple musculoskeletal (skin, muscle, joint) as well as peripheral and central nervous system structures (peripheral nerve, spinal cord, brain) are affected by Chiari I and syringomyelia and related disorders. Consequently, there are multiple types of pain syndromes that result from these structural abnormalities. While some patients experience typical back pain and/or headache disorders, others suffer from a combination of pain syndromes, which pose significant challenges to patients and their treating physicians.
The typical headache that occurs in Chiari I patients is occipital pain associated with valsalva maneuvers (coughing, sneezing, lifting, etc.). In younger subjects, the main challenge is to differentiate between primary headaches such as migraines or tension pain, and headaches due to this typical posterior fossa syndrome. Obtaining a detailed history is the most important factor that helps in obtaining the correct pain diagnosis. “Chiari” headaches often resolve with posterior fossa decompression. However, “Chiari” headaches may coexist with migraine headaches, which complicates treatment. On occasion, a treatment trial with a triptan (see tables below) may answer the question. If there is complete resolution of the headache with such treatment, this is diagnostic of migraine. Once migraine is established to be the predominant source of the headache, then a comprehensive treatment plan including pharmacological and non-pharmacological approaches is indicated (see tables below). Clinicians should also be aware of the frequent coexistence of musculoskeletal neck pain, which is best treated with physical therapy modalities.
Syringomyelia and related spinal disorders as a rule are associated with multiple sensory abnormalities, including pain. As with Chiari, different types of pain can coexist in a syrinx patient. The type, location, and severity of the pain is often dictated by the spinal level affected (e.g., arms vs. legs) and the length of time that the pain has existed. The type of pain may range from disagreeable unpleasant sensations to constant ongoing and episodic pain. When syringomyelia is severe or if it is left untreated for an extended period of time, this can result in a prototypical type of central neuropathic pain , meaning that the pain arises from the damaged spinal cord itself. This pain is very difficult to treat and often does not respond to surgical intervention on the syrinx or syrinx etiology. A syrinx patient may alternatively (or in addition) suffer from peripheral or radicular pain , which is more likely to respond to surgical intervention and traditional pain therapy (e.g., narcotics). These 2 types of pain have different clinical manifestations and are treated very differently. Central pain is often burning, aching, constant in character, usually associated with decreased sensation in the affected dermatome on the skin. In contrast, peripheral pain tends to be sharp, sudden, lancinating, with rare sensory loss. Peripheral pain is treated with narcotics and traditional pain medications, and often will respond to surgery to remove the cause of the pain (e.g., syrinx or Chiari), while central pain requires a combination of medications designed for chronic pain therapy (Gabapentin, etc.) and non-pharmacological modalities such as physical therapy and psychological counseling. The longer the duration of the pain before surgery, and the more unusual is the pain (burning, associated with sensory loss, etc.), the less likely the pain will improve with surgery. If the pain is still a significant problem postoperatively, and/or it interferes with the patient’s function and quality of life, then a comprehensive pain management program including pharmacological and non-pharmacological modalities should be developed at a specialized pain center. A pain specialist is ideally suited to determine the type of pain from which the patient suffers, and provide ongoing assessment and modifications to the treatment plan over the long term.
Multidisciplinary and multimodal pain treatment and management
|Pharmacological||Medications, infusions, topicals|
|Psychological||Cognitive-behavioral therapy, relaxation|
|Physical medicine modalities||Physical therapy, exercise program|
|Neurostimulation||Spinal cord, peripheral nerve|
|Intrathecal delivery of drugs||Medications|
|Analgesic Drug Classes||Medications Examples||Side Effects|
|Tricyclic antidepressants||nortriptyline, desiparmine||sedation, constipation|
|SNRI's antidepressants||duloxetine||nausea, vomiting, dizziness|
|a2d calcium anticonvulsants||gabapentin, pregabalin||dizziness, weight gain|
|Opioid analgesics (narcotics)||Morphine||sedation, constipation, nausea, dizziness|