IIMAGES DAY TO DAY I
Acute Subdural Haematoma (SDH)
Mimicking Extradural Haematoma (EDH)
Ani) Sharma, MCh
CT Scanjilms showing acute SDH as a biconvex lesiolland its appearance in sylvianarea. Presented
above is the CT Scan ofa patient who after an alcoholic bout, had afall and presented with
features ofloss ofconsciousness, vomiting and hemiparesis. Scalp examination did not.
reveal any bruising/haematoma. CT Scan showed an extra-axial bleed with mass
effect. No fracture was seen on bony window. He was operated upon for what
turned out to be acute SDH on surgery. He improved and was discharged.
Acute SDH is usually sickle or crescent shaped on CT scan. The inner surface of the haematoma out-
lines the contours of the brain and therefore has a characteristic sawtooth figure in the region of
sylvian fissure. Rarely, a large acute SDH may appear biconvex and resemble EDH. This is distinguished
from the latter by the appearance of its corners being drawn out to a fine point as compared to the
rounded anterior and posterior borgers formed by the dura, displaced by an EDH. In addition, the
irregula;- appearance ofthe inner border of SDH especially in rigion ofsylvian fissure is characteristic.
From the Neurosurgical Unit, Department of Surgery, Government Medical College, Jammu (J&K).
Correspondence to : Dr. Anil Sharma, Consultant Neurosurgeon, Neurosurgical Unit, Department of Surgery, Government Medical
College, Jammu (J&K).
Vol. I No.4, October-December 1999