Pain Characteristics in Syringomyelia
Pain in syringomyelia is predominantly characterized by segmental dysesthetic (burning) pain with hyperesthesia in a dermatomal distribution, occurring in approximately 37% of patients at presentation, and is anatomically correlated with syrinx extension into the dorsolateral quadrant of the spinal cord. 1
Primary Pain Phenotype
Dysesthetic burning pain is the hallmark sensory disturbance, described as a "cold burning pain" that is segmental in nature and corresponds to the level of spinal cord involvement 1, 2
Hyperesthesia and allodynia (increased painful response to light touch) are common accompanying features, with patients experiencing exaggerated pain responses to normally non-painful stimuli 1, 2
Trophic changes may develop in the affected dermatomes in a variable percentage of patients with dysesthetic pain 1
Anatomical Correlation
The dysesthetic pain syndrome correlates strongly with dorsolateral quadrant involvement of the spinal cord on MRI, with 84% of patients showing syrinx extension into this region on the same side and level as their pain 1
Structural damage severity directly correlates with pain intensity—greater fractional anisotropy reduction and fewer reconstructed nerve fibers on diffusion tensor imaging correlate with higher average daily pain scores (Spearman's ρ = -0.64) 3
Pain Subtypes and Clinical Patterns
Spontaneous pain only versus spontaneous plus evoked pain represent distinct phenotypes: patients with spontaneous pain alone have more severe spinal cord structural damage (Spearman's ρ = -0.93 correlation between pain intensity and fractional anisotropy), while those with both types have better preserved spinothalamic tracts 3
Deep spontaneous pain and paraesthesia/dysaesthesia (pins and needles/tingling) are negatively correlated with the number of reconstructed nerve fibers, suggesting different underlying mechanisms for various pain descriptors 3
Radicular pain can occur when cervical spondylosis causes syringomyelia through intermittent spinal cord compression 4
Associated Headache Considerations
- When headache accompanies syringomyelia, Chiari malformation should be evaluated first, as this is the most common form of syringomyelia and the likely source of cephalic symptoms rather than the thoracic syrinx itself 5
Critical Clinical Pitfalls
Pain may not improve with surgical treatment: despite successful syrinx collapse, 41% of patients report no improvement or intensification of dysesthetic pain postoperatively, making this a disabling and treatment-resistant complaint 1
Standard analgesics are typically ineffective: dysesthetic pain responds poorly to conventional analgesics, sedatives, antiepileptics, antispasmodics, and anti-inflammatory agents 1
Sympathetic involvement may occur: the pain has certain causalgia-like features, with some patients achieving relief from regional sympathetic blocks or stellate ganglionectomy, suggesting disturbance of pain-modulating centers in the dorsolateral spinal cord 1
Central pain remains poorly understood: the pathophysiological basis of chronic pain in syringomyelia remains poorly defined, and effective treatment remains elusive despite being one of the most disabling sensory disturbances associated with this condition 6