Syrinx

Presentation

A 48-year-old woman had worsening weakness and numbness of her left hand and leg (4+/5), hyperreflexia. Her entire neuraxis was imaged, and the only finding was a high thoracic syrinx.

Radiologic Findings

Postoperative axial magnetic resonance imaging (MRI) of the thoracic spine (Fig. 35-1) shows the syringosub-arachnoid shunt draining the syrinx.

FIGURE 35-1 Syringosubarachnoid shunt draining a thoracic syrinx.

Diagnosis

Syrinx

Treatment

Intraoperatively, an arachnoid web was found, which was lysed. A syringosubarachnoid shunt was placed.

Discussion

A syrinx occurs when a cyst forms within the spinal cord. This can be found with Chiari I malformations, or as a complication of trauma, tumor, meningitis, or hemorrhage. Sometimes the cause is not found. We have seen in our case series a patient who developed spinal cord injury, arachnoiditis, and a syrinx after hydrogen peroxide was accidentally injected into his lumbar drain intraoperatively. Although one cannot completely reverse the toxic effect of this action, immediate intervention could include widening the durotomy and copious irrigation with preservative-free normal saline.

Syrinx patients can experience pain, difficulty with temperature sensation, and weakness. MRI is the most sensitive test for diagnosis. If symptomatic, treatment is usually directed at the primary etiology, but if none is found, the cyst can be shunted.