Abstract 291: Iatrogenic Intracranial Hypotension with Pseudomeningocele, CSF Fistula and CSF Leaks Following Dural Repair and Spinal Cord Stimulator Placement
Authors: Arthur M. , Mikolajczak M. , Lee S. , Burela R. , Rao S. , Wright P. , Nierenburg H. 
Published: January 2025

Background
Intracranial hypotension (IH) is a rare complication of cerebrospinal fluid (CSF) leakage. It can occur either spontaneously (primary) or as a result of trauma or medical intervention (secondary or iatrogenic). The incidence of IH is approximately 5 per 10,000 cases annually. Iatrogenic IH can occur following procedures that involve dural injury, such as spinal surgery, spinal cord stimulator (SCS) lead migration, or lumbar puncture. Reduced CSF flow leads to a decrease in CSF volume and subsequent intracranial hypotension, manifesting as a postural headache. Diagnosis of a CSF leak or CSF venous fistula (CVF) is typically made using CT or MR myelography. Dynamic myelography is reserved for multiple level or high‐flow CSF leaks. Dural defects are commonly treated epidural blood patch or surgical repair. In CSF venous fistula (CVF), embolization therapy may be employed.

Objective:
We present a case of iatrogenic IH following traumatic dural injury due to SCS lead migration complicated by the development of a large pseudomeningocele, CVF and CSF leaks.

Methods
A 46‐year‐old female presented with disabling postural headaches. Her surgical history included an L4‐S1 posterior fusion and laminectomy complicated by durotomy and repair in 2003, followed by 2 epidural SCS placements and bilateral SI joint fusion. In 2010, she experienced intermittent headaches described as the worst of her life, which resolved after two months. Shortly before her current presentation, the headaches returned, accompanied by tinnitus, a sensation of underwater hearing, autonomic dysfunction, confusion, and brain fog, raising concern for a CSF leak. CT myelography revealed arachnoiditis and a large pseudomeningocele at L4‐L5, though no active CSF leak was identified. Nonetheless, the patient was referred to a CSF leak specialist and treated empirically with an epidural blood patch at T12‐L1, leading to cessation of her symptoms. Five months later, the patient suffered a fall, and her symptoms recurred. CT thoracic spine revealed migration of the lower SCS epidural lead into the thecal sac. A repeat CT myelogram showed a pseudomeningocele at the left L4‐L5 region with a possible extradural leak near the L4‐L5 pedicles and a CSF leak at the T12‐L1 SCS epidural lead. Due to suspected CSF leak at multiple levels, dynamic CT myelogram was employed. Dynamic CT myelogram revealed an expansion of contrast extravasation at the left L4‐L5 pedicles and vascular uptake of contrast in the left L4‐L5 neural foramina raising suspicion of a CVF versus systemic contrast absorption in the pseudomeningocele containing the CSF leak. The patient was treated with epidural blood patches at L3‐L4, L4‐L5, and T12‐L1, microsurgical repair of the pseudomeningocele with venous ligation, and a lumbar peritoneal shunt, which resulted in significant improvement of her postural headache symptoms. L4‐S1 posterior fusion revision was performed. SCS was unable to be removed due to fusion with the bone.

Conclusion
Iatrogenic IH can result from persistent, recurrent, or new CSF leaks even after dural repair. In patients who develop new or ongoing postural headaches following treatment, re‐evaluation of symptoms along with repeat CT myelography may be warranted to identify any underlying issues.