Covering of the Brain
Three layers make up the covering of the brain; inner-most is the pia mater, the middle layer is the arachnoid and the outer layer is the dura mater. The toughest layer is the dura mater. Below this layer is a space where subdural collections such as fluid or blood may occur.
In the subdural space, children may occasionally accumulate blood, cerebrospinal fluid or an infection. Subdural hematomas (blood) often develop after a traumatic event. Depending on the situation, these bloody collections may be observed or may on occasion need a surgical intervention (burr holes, craniotomy). Subdural hygromas (cerebrospinal fluid) may also occasionally need surgical treatment. Subdural empyemas (infection) often need surgical drainage coupled with antibiotic therapy.