Recurrent isolated abducens nerve paresis associated with persistent trigeminal artery variant.

We report a 74-year-old woman who presented with recurrent isolated abducens nerve paresis. Cranial magnetic resonance imaging revealed that the right abducens nerve was sandwiched between the right internal carotid artery and a persistent trigeminal artery (PTA) variant, which might have led to neurovascular compression of the abducens nerve, resulting in abducens nerve damage. Normal variants of PTA, which are cerebellar arteries originating from a precavernous portion of the internal carotid artery, must be carefully observed as such variants can potentially cause a neurovascular compression of the abducens nerve.