Patterns and predictors of isolated oculomotor nerve palsy recovery following mild traumatic brain injury

Abstract

Introduction: Oculomotor nerve palsy following mild traumatic brain injury is uncommon. The exact pathogenesis, management protocol and outcome of such patients is unclear in the absence of large series. This article attempts to analyze the patterns of injury and recovery in a series of twenty one patients with third cranial nerve palsy following mild traumatic brain injury (TBI). Materials and Methods: All patients admitted with mild head injury and third nerve involvement were included in the study. This retrospective study covered a three-year period from January 2015 to December 2017. Mild head injury was defined as patients with a Glasgow Coma score of 14 -15 and having a normal CT scan at admission. The clinical profile of the injury and recovery of the oculomotor nerve were jointly evaluated and followed up in the department of neurosurgery and ophthalmology. Results: Our study group included twenty one patients. Levator palpebrae superioris involvement with ptosis (95.23%) was the most consistently affected third nerve function followed by extraocular muscles (90.47%) and pupillary fibers (80.9%). Ptosis was partial in 11 patients and complete in nine. Of the extra ocular muscles, the most common muscles to be involved were the inferior rectus and the medial rectus which were involved in 19 patients (90.47%). Superior rectus involvement was seen in 13 patients and inferior oblique in nine patients. Imaging including thin section CT scans (all patients) and FIESTA MRI sequence (2 patients) did not reveal any significant abnormality. All our patients were managed conservatively. Steroids and corrective surgery was not tried in any patient. On follow up, after a mean period of 6 months, partial ptosis recovered completely while complete ptosis recovered only in four patients (44.4%). Of the seventeen patients with pupillary involvement, pupillary size and reaction improved in four (23.5%) and remained static in 13 patients. Of the extraocular muscles superior