Subacute Girdle-Band Pain in a Chronic Tetraplegic Patient With Syringomyelia Following Traumatic Spinal Cord Injury

PATIENT PRESENTATION A 76-yr-old man with a history including C4 AIS C tetraplegia secondary to traumatic spinal cord injury sustained 3 yrs prior, status post C3-C4 anterior/posterior cervical laminectomy and fusion complicated by syringomyelia and subarachnoid hemorrhage, was admitted with subacute (1–2 wks) band-like inferior-thoracic and superior-abdominal pressure with associated paresthesia and spasms. The patient reported that his worsened spasms had impaired his transfers. Examination revealed T4-T8 dermatomal hypesthesia but was otherwise consistent with stable C4 tetraplegia. Differential diagnosis initially included cardiac ischemia, gastroesophageal reflux, or syrinx expansion. DIAGNOSTIC RESULTS Initial workup included electrocardiogram, high-sensitivity troponin, B-type natriuretic peptide, transthoracic echocardiogram, and upper endoscopy, which were unremarkable. Magnetic resonance imaging of the cervical and thoracic spine revealed stable C3-C4 syrinx (Fig. 1), as well as a new extramedullary, intradural cystic lesion, hyperintense on T2, and surrounding the thoracic cord (Figs. 2A–C), suggestive of intradural spinal arachnoid cyst (SAC). Abnormal cord signal changes were noted below T4-T5 (Fig. 2C), consistent with concurrent dorsal and ventral thoracic cord compression (Figs. 2A, B). The presence of both sensory disturbance and pain was unsurprising, given circumferential cord compression. The SAC’s ventral compression of spinothalamic tract neurons within the anterior white commissure potentially contributed to segmental hypesthesia. Preservation of the patient’s truncal coordination was attributed in part to the known limited descending motor fibers within the anterior cortical spinal tract.FIGURE 1: Sagittal (A) and axial (B) T2-weighted magnetic resonance imaging sequence showing focal cervical cord syrinx at C3-C4.FIGURE 2: Axial T2-weighted magnetic resonance imaging sequence demonstrating hyperintense dorsal and ventral extramedullary, intradural cyst in the thoracic spine, with (A) maximum dorsal cord compression caudally and (B) circumferential compression more rostrally. C, Sagittal T2-weighted magnetic resonance imaging sequence image with abnormal cord signal changes most pronounced caudal to the maximum cord compression at T4–5.OUTCOME Neurosurgery was consulted, however the consultants deferred duraplasty or drainage given stable functional status, instead opting for serial observation, as neuropathic pain and hypesthesia are unlikely to resolve compared with weakness.1 Symptoms were managed conservatively with titration of neuropathic pain and antispasmodic medications. Acquired SACs are often secondary to arachnoid mater fibrosis in the setting of arachnoiditis, due to trauma, iatrogenesis, meningitis, and subarachnoid hemorrhage. This SAC was likely acquired, given previous traumatic spinal cord injury, surgical intervention, and subarachnoid hemorrhage. LEARNING POINTS SACs are collections of cerebrospinal fluid within arachnoid mater, which may be either congenital or acquired, located ventral, dorsal or lateral to the cord (with majority located dorsally),2 and situated extradural, intradural, or intramedullary.2,3 SACs are underrecognized late complications of traumatic spinal cord injury, which may occur alongside syringomyelia due to cerebrospinal fluid obstruction, and are easily missed on imaging due to their thin walls.2 SAC presentation varies from asymptomatic to severe myelopathy.4 SACs with spinal cord compression may cause progressive symptoms and have been known to be exacerbated with Valsalva and mistaken for cardiac chest pain.3,5