# One of the earlier signs of cavernous sinus thrombosis is due to deficit in the function of:
A. Trochlear nerve
B. Abducens nerve
C. Oculomotor nerve
D. Ophthalmic division of trigeminal nerve
The correct answer is B. Abducens nerve.
Because the abducens nerve (cranial nerve VI) is usually the first nerve to become involved due to its location in the lateral wall of the cavernous sinus, an early sign may be an internal strabismus.
Ref: ORAL AND MAXILLOFACIAL PATHOLOGY, A Rationale for Diagnosis and Treatment, Second Edition Page no 77