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Radiology - Diagnostic

Training Level

Resident PGY 2


Henry Ford Hospital


Case presentation: We present a 67-year-old female with a long-standing history of occipital headaches. The patient previously underwent surgical decompression for suspected Chiari I malformation without relief. A patch duroplasty was performed, but symptoms persisted with new gait instability and altered mental status. Imaging at our institution showed findings of intracranial hypotension (IH), as well as a right pleural effusion. MR myelogram showed a meningocele abutting the pleural effusion and fluid sampling was positive for beta-2 transferrin. Blood patches were attempted, but the meningocele ultimately required surgical ligation with symptomatic relief.Imaging Findings: Sagittal T1-weighted MR image at presentation (A) demonstrates findings of IH, including pituitary enlargement (dashed arrow), decreased mamillopontine distance (short white arrow), ventral pons flattening (long white arrow), and caudal cerebellar tonsillar displacement (black arrow). Chest CT (C) and MR myelogram (D) demonstrate a right thoracic meningocele abutting a pleural effusion. Imaging following meningocele ligation (D) shows improvement in the findings of IH. Discussion: Intracranial hypotension (IH) most commonly presents with postural headache, but symptoms can include cranial nerve palsies, visual disturbances, and rarely, severe encephalopathy. IH may be spontaneous (SIH) or related to prior injury, including iatrogenic causes such as lumbar puncture and surgery. The etiology for SIH is not always found, but pre-existing weakness of the dural sac, such as arachnoid diverticula, as well as minor trauma can be associated. Subarachnoid-pleural CSF fistula is a rare cause of IH and is usually related to trauma or surgery, although spontaneous rupture of a thoracic meningocele into the pleural cavity has been described. Conclusion: Knowledge of the characteristic intracranial imaging findings of IH is important so as to avoid misdiagnosis and unnecessary treatment for alternate etiologies. Understanding potential causes and imaging work-up is also important. We present a rare of case SIH secondary to subarachnoid-pleural CSF fistula.

Presentation Date


Unusual Headaches due to Subarachnoid-Pleural CSF Fistula