ISOLATED INTRACRANIAL HYPERTENSION AS A LATE MANIFESTATION OF SINUS VENOUS COMPRESSION SECONDARY TO A DEPRESSED SKULL FRACTURE

Objectives: Depressed skull fractures can be complicated by laceration or compression of the cerebral venous sinuses. Raised intracranial pressure may be the only sign of venous obstruction and the clinical presentation can mimic idiopathic intracranial hypertension (IIH).

Methods: We report a 12 year old girl who presented with diplopia 3 weeks after being struck behind the right ear. The injury resulted in a parieto-occipital scalp laceration but a skull fracture was not identified at the time on plain x-rays. Examination revealed a right 6th nerve palsy and bilateral papilloedema. Cranial CT showed a depressed right occipital skull fracture. CSF opening pressure was 58cm H20 and closing pressure was 17cm H2O but there was no improvement in her diplopia post lumbar puncture. Contrast MRI showed a depressed bony fragment compressing the right transverse sinus.

Results: A craniotomy was performed to elevate the skull fracture. The bony fragment had not breached the wall of the transverse sinus and there was immediate restoration of flow on elevating the fracture. Contrast MRI 2 months following surgery showed elevation of the skull fracture and a patent right transverse sinus with good flow on MR venography (MRV). Eye examination 3 months following surgery showed complete resolution of the right 6th nerve palsy and papilloedema.

Conclusion: It is important to ask about recent head trauma in children presenting IIH because cerebral venous sinus compression from depressed skull fractures can present with an identical clinical picture to IIH. MRV is indicated in such cases.