Author(s)

S.R Vydianath

Patient

male, 16 year(s)

Patient with a history of loss of consciousness lasting less than 5 minutes after a road traffic accident. No external injuries or focal neurological deficits were present.

The patient presented to the Emergency Department after being involved in a road traffic accident with a history of loss of consciousness lasting less than 5 minutes. He also had a mild headache, but no nausea or photophobia. On examination he did not have any external injuries or focal neurological deficit.

Skull x-rays were performed to look for a vault fracture. The lateral skull x-ray is shown (Fig. 1). The sella turcica appears to be quite shallow because it is grossly elongated and has a shallow anterior convexity. The patient went on to have a CT scan of the brain, which showed no space-occupying lesions, leading to the conclusion that the sella in this patient was a normal variant.

The J-shaped sella (also called 'shoe-shaped' or 'omega-shaped' sella) is a rather peculiarly shaped sella turcica but is merely due to an exaggeration of the normal slight impression of the sulcus chiasmaticus, resulting in an elongated sella with a shallow anterior convexity.

This may be rarely seen in normal adult skulls, but is a slightly more common appearance in the paediatric age group (incidence of 5-6%). Although it can arise as a normal variant certain underlying causes which can expand the sella need to be kept in mind when reviewing such films. The important pathological causes of such an appearance are chronic hydrocephalus and raised intracranial pressure, causes of 'gargoylism' such as Morquio's syndrome, Hunter's syndrome and other mucopolysaccharidoses, glioma of the optic chiasm and the 'empty sella syndrome'.