Can giant cell arteritis present with a partial cranial neuropathy?

Giant cell arteritis (although giant cells on temporal artery biopsy are not a sine qua non) most typically presents to the neuro-ophthalmologist with ischemic optic neuropathy (usually anterior and sometimes posterior).

Ophthalmoplegia is uncommon in GCA but has been attributed to oculomotor and abducens palsies (Walsh et al., PMID 13649840), however histopathological studies of the ocular motor system in GCA are very rare. Of note, an autopsy of an 80 y.o. man with biopsy proven GCA, global oph...

Yes. Although we most commonly think of giant cell arteritis (GCA) when an elderly patient presents with headache and vision loss from an ischemic optic neuropathy (AION or PION) or central retinal artery occlusion (CRAO), other cranial nerves can be affected as well. Ischemic third, fourth and sixth cranial nerve palsies have all been reported in the setting of GCA and may be complete or incomplete.

Yes, all individuals over the age of 50 years with a new ocular motor cranial nerve palsy should undergo a screening test for giant cell arteritis which includes serum ESR, CRP, and CBC (specifically looking for thrombocytosis). Admittedly, the yield is low. However, it is really important to have a systematic way of approaching certain problems to reduce errors that can be caused by a number of cognitive biases.