Epidural abscess with extension to subperiosteum

Ray Ballinger, MD, PhD

Straub Clinic and Hospital

rballinger at straub.net

Abstract

35 y/o woman with soft tissue swelling on the back of her head

Keywords

MRI CT head neuro

Publication Date: 30 October 2003

History and Images

35 y/o woman with headache and soft tissue swelling on the back of her head

CT without contrast CT with contrast CT bone window T1-weighted sagittal T2-weighted axial

Findings

A lenticular-shape fluid collection is seen in the right occipital region that shows an enhancing rim with IV contrast. A defect is seen in the calvarium with an extracranial, rim-enhancing collection. The MRI was actually performed 2 weeks earlier for headache however the findings were missed until the patient returned for the CT scan.

Diagnosis

Epidural abscess with extension through calvarium resulting in a subperiosteal abscess

Confirmation:

Surgical Drainage

Discussion

This is an unusual case. Intracranial epidural abscesses occur only about 20% as frequent as subdural abscesses and are frequently associated with a recent surgical procedure or trauma. Epidural abscesses are associated with paranasal sinus infections, mastoiditis and otitis. This patient has a history of otitis a month or two before the initial MR scan but did not have any trauma or surgical procedure.

This case is also somewhat similar to the Pott's Puffy Tumor which is a case of frontal sinusitis with associated osteomyelitis and subperiosteal abscess. Epidural abscess can be a complication of Pott's Puffy Tumor. In this case, it appears that the epidural abscess occured first, probably as a complication of otitis media with secondary osteomyelitis and development of a subperiosteal abscess.