Abstract

Background: Pain is a common feature of microvascular ischemic ocular motor cranial nerve palsies (MP). The natural history of pain in this condition has not been studied. The purpose of this report is to define the pain spectrum in isolated MP, with special reference to diabetics versus nondiabetics.

Design and methods: Retrospective and prospective chart review was performed on 87 patients with acute onset MP of a single cranial nerve (CN III = oculomotor, CN IV = trochlear, or CN VI = abducens) that progressively improved or resolved over 6 months.

Results: Five of the 87 patients had two events, making the total number of events 92. There were 48 (52.2%) CN VI palsies, 39 (42.4%) CN III palsies, and 5 (5.4%) CN IV palsies. Thirty-six (41%) patients had diabetes. Pain was present in 57 (62%) events. The majority of diabetics and non-diabetics had pain. Pain preceded diplopia by 5.8 days (±5.5) in one third of events. There was a trend towards greater pain with CN III palsies but this was not statistically significant. Patients who experienced severe pain tended to have pain for a longer duration (26.4 ± 21.7 days versus 10.8 ± 8.3 and 9.5 ± 9 days for mild and moderate pain, respectively). There was no correlation between having diabetes and experiencing pain.

Conclusions: The majority of MP are painful, regardless of the presence or absence of diabetes. Pain may occur prior to or concurrent with diplopia. Nondiabetics and diabetics presented with similar pain characteristics, contrary to the belief that diabetics have more pain associated with MP.