Cranial nerve III palsy resulting from intracranial hypotension caused by cerebrospinal fluid leak after paraspinal tumor resection: etiology and treatment options.

BACKGROUND CONTEXT

Intracranial hypotension typically occurs spontaneously. Acquired or secondary intracranial hypotension is less common but has been reported after spinal procedures, such as lumbar puncture. Cranial nerve (CN) III palsy is a rare sequela of intracranial hypotension. There are currently no established or standard interventions to treat intracranial hypotension.

PURPOSE

To describe a case of delayed CN III palsy resulting from intracranial hypotension because of a spinal cerebrospinal fluid (CSF) leak occurring during resection of a paraspinous tumor.

STUDY DESIGN

Case report.

METHODS

A 41-year-old woman underwent resection of a large thoracic schwannoma complicated by dural tear. Postoperatively, the patient was neurologically normal. She subsequently became acutely unresponsive and required reintubation. She awakened with intermittent headaches and was noted to have a right ptosis, which progressed to a complete right CN III palsy.

RESULTS

Initial head computed tomography showed evidence of a small, right-sided subdural hematoma. Magnetic resonance imaging (MRI) of the brain showed diffuse leptomeningeal enhancement and crowding of the foramen magnum consistent with intracranial hypotension. The patient's symptoms were treated successfully with flat bed rest. She fully recovered by time of discharge and at 6-month follow-up was neurologically normal.

CONCLUSIONS

Spinal surgery complicated by CSF leak is a potential cause of intracranial hypotension. Although most commonly associated with positional headaches, intracranial hypotension can cause uncommon symptoms, including acute mental status changes and CN deficits. Symptoms highly suspicious for intracranial hypotension accompanied by MRI of the brain are important for establishing a diagnosis of intracranial hypotension. Conservative treatment should be considered before attempting invasive intervention. As in the case presented, simple bed rest was a successful treatment option.