(606) A Rare Case of Community-Acquired Subdural Empyema

Introduction: Subdural empyema is primarily nosocomial, linked to penetrating head injuries, cranial surgeries, skull fractures, infected hematomas, or untreated sinus/ear infections. Literature on community-acquired cases is scant.

Description: A 76-year-old female with a past medical history of hypertension and hypothyroidism presented with a one-month history of progressively worsening retro-orbital to frontal headache accompanied by left lower extremity weakness. A week prior, her PCP prescribed steroids for possible giant cell arteritis. Further investigation revealed a tree branch struck her in the face months before presentation. Physical exam showed right anisocoria, flattening of the nasolabial fold, and left lower extremity weakness. CT head revealed hypodensities in the parasagittal right frontal and posterior left frontal lobes suspicious for acute infarctions, and right-sided subacute to chronic subdural hematomas. Neurosurgery promptly operated and found purulent material with friable dura matter; they performed a washout and repaired an anterior fossa skull base defect. Levetiracetam and antibiotics were administered.

Post-op ICU course was complicated by acute encephalopathy warranting intubation. Pertinent labs showed WBC of 26 (86% PMN), hemoglobin of 11, CRP of 30 and lactic acid of 1.5. IV Vancomycin, ceftriaxone, and metronidazole were started; Infectious Disease was consulted. CT head was suggestive of left maxillary sinusitis. MRI brain revealed diffusion restriction within the right frontal lobe concerning for acute infarcts likely due to vasospasm, calvarial osteomyelitis, an osseous defect between the medial inner table of the left frontal sinus, and subjacent anterior medial right frontal convexity. Surgical cultures grew S. intermedius and blood cultures grew S. anginosus. She suffered a non-convulsive seizure treated with Lacosamide. She ultimately required a tracheostomy and PEG tube. After 3 months, she regained consciousness and strength, and transitioned to a long-term care facility.

Discussion: This case underscores the rare community acquisition of subdural empyema, likely from untreated sinusitis and skull base fracture. Management necessitates a multidisciplinary approach, emphasizing its critical diagnostic and therapeutic considerations.