Outcomes of half-width vertical rectus transposition augmented with posterior fixation sutures for sixth cranial nerve palsy

AIM: To describe the experience with half-width vertical muscles transposition (VRT) augmented with posterior fixation sutures. METHODS: The clinical charts of all patients, who underwent half-width VRT augmented with posterior fixation sutures for sixth cranial nerve palsy from January 2003 to December 2018, were retrospectively reviewed. For each patient, pre- and post-operatively, the largest measured angle was used for the calculations, usually resulting with the angle for distance, except in young infants, where measurements were made at near fixation using the Krimsky test. RESULTS: Fifteen patients met the inclusion criteria for the study, of them 9 (60.0%) had also medial rectus muscle recession at the time of surgery. Mean follow-up period was 21.4±23.2mo (range 1.5-82mo). Preoperative mean esotropia was 51.3±19.7 prism diopter (PD; range 20-90 PD). Postoperative mean deviation on final follow-up was 7.7±20.2 PD (range -40 to 35 PD; P=0.018). In all patients with preoperative abnormal head position, improvement was noted. Ten (66.7%) patients had improvement in abduction and 10 (66.7%) patients reported improvement in their diplopia, by final follow-up. The addition of medial rectus recession was correlated with a larger change in postoperative horizontal deviation compared to baseline (P=0.026). Two (13.3%) patients developed a vertical deviation in the immediate postoperative period which had resolved in one of them. CONCLUSION: Half-width VRT augmented with posterior fixation suture, with or without medial rectus muscle recession, is an effective and safe procedure for esotropia associated with sixth cranial nerve palsy. A major improvement in the angle of deviation is expected. Most patients will have improvement in their abnormal head position and diplopia.

A Rare Case of Traumatic Bilateral Sixth Cranial Nerve Palsy

Traumatic bilateral sixth cranial nerve palsy is a rare condition which is typically associated with additional intracranial, skull, and cervical spine injuries. We describe a case of complete bilateral sixth nerve palsy in a 28-year-old female patient after an alleged motor vehicle accident. She had altered level of consciousness but no intracranial lesion or associated skull or cervical spine fracture was detected. In this case, we discussed the differential diagnoses, initial workup, and possible treatment options in cases of traumatic 6th nerve palsy.

Sixth Cranial Nerve Palsy and Vertigo Caused by Vertebrobasilar Insufficiency

A 38-year-old woman presented with a week’s history of binocular horizontal double vision and acute vertigo with gaze-induced nystagmus. We considered a diagnosis of one of the six syndromes of the sixth cranial nerve and evaluated several causes. She had history of severe anemia, vitamin B12 deficiency, and hypertension. Magnetic resonance imaging with angiography showed stenosis of the right vertebral artery and hyperintensity on both basal ganglia. As we describe here, we should consider vertebrobasilar insufficiency as a cause for sixth cranial nerve palsy if a patient has high risk for microvascular ischemia, even in the absence of acute brain hemorrhage or infarction.