A 9 year old boy with Fallot's tetralogy, had high grade fever followed by focal seizure 2 days prior to hospital admission. His blood counts were increased and predominantly polymorphs. CT scan of the head showed a focal lesion suggestive of an abscess. Where would be the commonest location of brain abscess in this patient?
Cerebellum
Thalamus
Temporal lobe
Parietal lobe
Cyanotic congenital hea diseases like TOF are a significant risk factor for brain abscess. The moality associated with the condition is very high. Focal ischemia in the brain, paicularly the parietal lobe is the cause. Otogenic : Temporal lobe and cerebellum ; Paranasal sinuses : Frontal Lobe. Intracranial abscesses can originate from infection of contiguous structures (eg, otitis media, dental infection, mastoiditis, sinusitis) secondary to hematogenous spread from a remote site (especially in patients with cyanotic congenital hea disease), after skull trauma or surgery, and, rarely, following meningitis. In at least 15% of cases, no source can be identified.