Keywords
cerebral abscess - cerebral infarct - meningitis
Introduction
Cerebral abscess complicating cerebral infarction is rare. Only 13 cases have been reported in the literature so far.[1]
Case Report
A 42-year-old man, nonhypertensive, nondiabetic, diagnosed with malignant cerebral infarct of the left anterior cerebral artery (ACA) and middle cerebral artery (MCA) ([Fig. 1]) underwent decompressive craniotomy for raised intracranial pressure (ICP). He also underwent tracheostomy in view of low Glasgow coma scale (GCS) and severe lower respiratory infection (LRI). With aggressive treatment and a tracheostomy, he regained consciousness, obeying simple commands. After 5 weeks, his craniotomy flap became very much lax with features of sunken skin flap syndrome. Follow-up computed tomography (CT) of the brain ([Fig. 1]) showed large gliotic area with sunken flap. Therefore, cranioplasty was planned. During surgery, false dura was inadvertently torn and pus started coming out. The false dura tear widened, liberal corticotomy was done, and 150 mL of pus was evacuated. Capsule was de-roofed. Whole infarcted brain had converted into a cavity full of pus ([Fig. 2]). The abscess cavity was thoroughly washed with saline and Metrogyl. Cranioplasty was deferred. No signs of infection were noted in the cranial wound. Gram stain, acid-fast Bacilli (AFB) stain, and fungal staining of pus were negative. Histopathology examination (HPE) revealed acute-on-chronic nonspecific inflammation with suppuration and foamy histiocytes. Pus culture was negative. The patient had meningitis in the postoperative period but recovered well.
Fig. 1 Preoperative MRI showing anterior cerebral artery and middle cerebral artery infarct. CT brain prior to planned cranioplasty shows features of sunken skin flap syndrome.
Fig. 2 Solid arrows in intraoperative images showing pus and abscess cavity in various stages of surgery.
Discussion
Cerebrovascular accident (CVA) complications are enormous owing to the associated comorbids, extent of brain damage, and old age.[2] The infarcted brain acts like a fertile ground for the pathogens to grow.[3] Abscess following infarction is reported as early as 12 days to 14 months after stroke.[4]
[5] Antibiotic treatment alone proves fatal. Aggressive surgical resection is the only hope. Disruption of blood–brain barrier by the vascular event facilitates microbial seeding in the event of bacteremia, leading to abscess formation.[6] Ischemia further limits the immune system to combat invading pathogens. Surgical treatment of stroke does not seem to be a causative factor for abcess.[1] The main presenting symptom is fever, bulging skin flap in postsurgical patients, and the most common offending organisms are Streptococcus and Staphylococcus. Our case is unique, as the patient had neither fever nor bulging skin flap and incidental intraoperative detection of abscess with negative pus culture.
Conclusion
Uncontrolled fever in a stroke patient should raise the suspicion of this rare complication. A routine contrast CT of the brain prior to cranioplasty may pick up this complication in asymptomatic patients. Conservative treatment alone proves fatal in almost all cases. Extensive surgical debridement of the abscess with postoperative antibiotics cover offers the best outcome for these patients.
