Falcotentorial subdural empyema: analysis of 10 cases.

OBJECT: Parafalcine subdural empyema and those along the superior and inferior surface of the tentorium are rare entities. We present a series of 10 patients where we have attempted to describe the pathophysiology, clinical features, and management of subdural empyema.

METHODS: The study group included 10 cases of falcotentorial subdural empyemas managed between 2004 and 2010. The mean age group was 14.4 years. Seven patients had empyema along the falx or superior surface of tent, and the remaining three had empyema along the inferior surface of tent. Fever, raised intracranial pressure symptoms, falx syndrome, and seizures were the usual presenting features. These patients had an indolent presentation as compared to convexity subdural empyemas. The diagnosis was made based on radiology. Chronic suppurative otitis media was a causative factor in five patients; in the remaining patients, the source was ascribed to be hematogenous. All patients were treated with antibiotic therapy (6 weeks) ± surgery. Two patients were treated conservatively, and the remaining eight patients underwent definitive surgery in the form of craniotomy (supratentorial)/craniectomy (infratentorial) and evacuation of pus. The pus was limited within two leaves, one adherent to the falx/tent and the other one to the pia-arachnoid of adjacent parenchyma. The wall along the falx or tent could be peeled off easily and was excised in all cases to lay open the cavity widely. The wall along pia-arachnoid was left as it is. Pus culture was positive in four and blood culture positive in two cases. There was only a single mortality in our series. The outcome was assessed by the Glasgow Outcome Scale. The mean duration of follow-up was for 18.8 months, and all patients who survived had a good outcome.

CONCLUSION: Falcotentorial empyema remains a rare entity. The presentation is indolent as compared to convexity subdural empyemas, possibly due to its limitation secondary to arachnoid adhesions at the junction of falx, tent, and convexity dura. The main stay of management remains craniotomy, evacuation, and partial excision of the wall, laying it completely open, unless it is extremely thin. With appropriate surgery and antibiotic therapy, a good outcome can be expected.