510 - An Unusual Case of Spontaneous Subdural Hematomas and Symptomatic Perineural Cyst Ruptures

Cerebrospinal fluid leakage associated with perineural cyst rupture following subdural hematomas

Case Description:

A 68-year-old male initially presented with ten days of occipital headaches and was found to have spontaneous bilateral subdural hematomas with leftward midline shift. He underwent middle meningeal artery embolization prior to discharge but represented a day later with altered mental status. Brain magnetic resonance imaging (MRI) showed a new infarct in the right caudate head and splenium with stable hematomas. Despite improvement in mental status, the patient had persistent orthostatic headaches, which improved with the Trendelenburg position, raising suspicion for cerebrospinal fluid (CSF) leakage. Spine MRI demonstrated multilevel thoracic perineural cysts with computed tomography (CT) myelogram confirming thoracic nerve root sleeve cysts without clear venous fistula. CT-guided thoracic epidural blood patches were performed targeting foraminal cysts at T7-T8 and T9-10 levels with subsequent improvement of headaches. 

Discussions:

Perineural cysts are CSF filled sacs that form near the dorsal root ganglion, usually in the sacrum and rarely in the thoracic area. It affects less than 5% of the adult population with the majority asymptomatic. Ruptured perineural cysts may present with neurologic symptoms including weakness, bowel and bladder dysfunction, headaches, and altered mental status. The resorption of subdural hematomas through meningeal lymphatic vessels may lead to increased CSF pressure indirectly causing extravasation of CSF from the perineural cysts. 

Conclusions: We present a rare case of symptomatic thoracic perineural cyst ruptures with CSF leakage following spontaneous subdural hematomas that were successfully treated with epidural blood patches.