Orbital Apex Syndrome, Intracranial and Dural Involvement in Giant Cell Arteritis ( GCA )

Orbital apex syndrome and posterior ischaemic optic neuropathy are rare presentations of GCA and are clinically characterized by complex opthalmoplegia with 2nd, 3rd, 4th, 5th (ophthalmic division) and 6th cranial nerve palsies. More than 80% of visual loss in GCA are due to arteritic anterior optic ischaemic neuropathy (A-AION) with clinical evidence of optic disc swelling. A major pitfall in diagnosis is the presence of a normal optic disc despite visual loss, albeit rare, can be due to posterior ischaemic optic neuropathy (PION) or cortical infarct involving calcarine cortices and requires a high index of clinical suspicion. GCA predominantly affects cranial and extracranial vessels with elastic membranes. On the contrary, true intracranial vessel and dural involvement in GCA are exceedingly rare and are not well documented, as the vessels are devoid of elastic membranes upon entering the dura. Intracranial involvement may result in altered sensorium ,localizing signs , speech and memory deficits. Neuroimaging may show multifocal dural thickening and enhancement , which can resolve with treatment . We describe a 62 year old male patient with underlying diabetes mellitus, end stage renal disease on hemodialysis and hypertension ,presenting with new onset headache, jaw claudication, bilateral complex opthalmoplegia and posterior ischaemic optic neuropathy. He was diagnosed with GCA with bilateral orbital apex syndrome. He had fluctuating level of consciousness, became comatose and was intubated for cerebral protection. Unfortunately, his condition deteriorated rapidly and he succumbed. His mental deterioration was attributed to intracranial vessel and dural involvement. This case highlights the atypical and rare manifestation of GCA.