A 65-year-old man developed subacute horizontal diplopia due to left-abducens nerve (AN) palsy and excessive left-eye tearing. Brain-MRI revealed a hyperintense T2-lesion with an elongated course within the left-carotid canal, presenting homogenous contrast-enhancement (Figure-1). The imaging findings were characteristic for an internal-carotid-artery sympathetic plexus (ICSP) schwannoma compressing the left-AN. Subsequent irritation of the deep petrosal nerve originating directly from ICSP and continuing as the vidian nerve may have led to the lacrimal gland edema and excessive left-eye tearing (Figure-2).

ICSP schwannoma represents an uncommon cause of AN palsy that may also manifest with excessive ipsilateral-eye tearing due to vidian nerve involvement.