Methicillin resistant
Our patient, a previously healthy 12-year-old male, presented with acute MRSA sinusitis and rapid intracranial extension. The clinical case was complicated by a marginal vancomycin susceptibility (
A previously healthy 12-year-old male with a history of intermittent migraines was admitted with acute onset of altered mental status and facial swelling. The patient had symptoms of headache, “upset stomach,” increasing fatigue, and tactile fever for two days prior to admission. On the day of admission he was found to be minimally responsive with significant swelling to the left aspect of the face, yellowish discharge from the left eye, and a protuberance from the forehead. A noncontrast head CT scan done at an outside health care facility demonstrated bilateral orbital cellulitis, pansinusitis, and possible venous sinus thrombosis prompting transfer to a pediatric hospital.
On admission, the complete blood count (CBC) revealed a white blood cell count of 8400 cells/
(a) MRI of the brain showing sagittal T1-weighted image after administration of contrast. The fluid collection reported to have a thin enhancing wall ran along the dorsal aspect of the superior sagittal sinus. (b) MRI of the brain showing coronal T1-weighted image after administration of contrast. Diffuse smooth dural enhancement is noted, bilaterally.
Neurosurgical consultation was requested for surgical drainage of the intracranial abscess, but operative intervention was refused citing that the collection was epidural and not contributing to a mass effect. Neurosurgical consultants questioned whether the collection was an abscess, despite the patient’s history, symptomatology, and imaging strongly suggesting that this was a case of acute bacterial sinusitis with rapid extension intracranially, orbitally, and subcutaneously.
Initial peripheral blood culture was positive at 14 hours of incubation and identified as MRSA. Significant concern was raised about the MRSA having an MIC of 2 mg/L, which is the upper limit of susceptible, given the challenges of vancomycin penetration into an intracranial abscess. Because the epidural MRSA abscess was not drained initially, rifampin was added. It took 4 days to achieve a target vancomycin trough level of 17
The patient remained febrile, clinically unstable, and intubated during the first three days of hospitalization. A repeat MRI on day three of hospitalization was interpreted by the radiologist as a mild increase in size of the epidural abscess in the superior midline, but surgical intervention was again deferred by neurosurgical consultants. The patient’s clinical status did not improve on antibiotics, and a head MRI on the sixth day of hospitalization showed an increased size of the epidural hematoma with a new abscess along the outer table of the left frontal bone and a small subdural fluid collection along the anterior left frontal lobe. A craniotomy procedure with abscess drainage was then performed recovering purulent fluid, all cultures of which grew MRSA, demonstrating the persistence of the organism in the intracranial abscess. On hospital day ten otolaryngology surgeons performed bilateral maxillary antrostomies, bilateral ethmoidectomies, bilateral frontal sinus drainage, and left orbital subperiosteal abscess drainage. MRSA recovered from the frontal sinus demonstrated new resistance to rifampin, which was then discontinued. On hospital day thirteen a right-sided thoracotomy was performed to drain an empyema, which grew MRSA. After four weeks of hospitalization the patient was discharged home on antibiotics and has subsequently made a complete recovery. Although a formal evaluation of the patient’s immune system was not performed, he had a normal globulin fraction of 3 gm/dL suggesting that a major deficiency of antibody production was unlikely.
Community-associated MRSA has been the predominant cause of skin and soft tissue infections in North America for the past decade [
This case additionally illustrates the importance of timely drainage of an intracranial MRSA abscess. MRSA subperiosteal abscesses in orbital infections have been noted to be increasing in incidence and are associate with a more aggressive disease course than for other organisms, leading to recommendations for empiric antibiotic coverage with a very low threshold for surgical intervention [
Delayed surgical intervention has also been associated with increasing MIC values for vancomycin leading to the development of resistance (VISA) and heteroresistance (hVISA) [