Strabismus surgery outcomes for internuclear ophthalmoplegia with exotropia.

Exotropia (XT) in internuclear ophthalmoplegia (INO) is a difficult problem to treat. The purpose of this study is to describe surgical approaches in treating INO and glean insight into various pre-operative factors that may affect outcomes for XT in INO. We conducted a retrospective review from 1 January 1995 - 5 January 2021 and identified seven patients with INO who underwent strabismus surgery for XT. Patient age, sex, etiology of INO, pre-operative alignment and sensorimotor exam, presence of diplopia, surgery performed, subsequent surgeries, use of adjustable sutures, post-operative alignment, presence of post-operative diplopia, presence of post-operative diplopia with use of prism correction, and length of follow-up were all collected. Initial surgeries undertaken included unilateral medial rectus (MR) plication and lateral rectus (LR) recession, bilateral medial rectus (MR) plications or resections, or bilateral MR plications combined with either unilateral or bilateral LR recessions. Chart review yielded ten charts, however two were excluded due to manifest esotropia (ET), and one was excluded due to incomplete records. Seven total patients were used in final analysis. The cohort age range was from 29 to 79 years. Pre-operative horizontal distance alignment ranged from 35 to 95 XT with an average exodeviation of 67.8 ± 22.6 prism diopters (PD). Horizontal adduction deficit ranged from -1 to -4 and was present bilaterally in all patients. A variety of initial surgical approaches were undertaken. After two muscle surgeries, distance deviation had an average change of 57.3 PD. After three muscle surgeries, distance deviation had an average change of 75 PD. After four muscle surgeries, distance deviation had an average change of 60 PD. Three patients required additional surgery for XT. Time to follow-up ranged from 1 to 58 months. Horizontal distance alignment in primary gaze at latest follow-up ranged from 30 ET to 30 XT with an average of 0 (orthotropia) ± 16.0 PD. One patient had a consecutive esotropia of 30 PD, one had a persistent exotropia of 30 PD, and five patients were orthotropic at distance. All patients reported relief of diplopia in primary gaze at near and distance either with or without use of prism. Horizontal ductions improved to some degree in all patients. Horizontal rectus surgery can treat many cases of XT in INO. Surgeons should consider INO etiology and concomitant vertical deviations when considering surgery. The degree of pre-operative adduction limitation is another important factor, though did not always dictate final motor and sensory outcomes.

Delayed diagnosis of cranial neuropathies from perineural spread of skin cancer.

Perineural spread (PNS) to cranial nerves (CNs) by cutaneous malignancies is difficult to diagnose given the indolent course and often late or absent findings on brain imaging. A 68-year-old white man with multiple cranial neuropathies secondary to PNS by squamous cell carcinoma had negative high-quality neuroimaging for 5.25 years. He first developed left facial numbness, followed 39 months later by a left CN VI palsy. Subsequent examinations over 2 years showed involvement of left seventh, right trigeminal V1-V3, and right sixth, and bilateral third nerve palsies. Repeat high-quality brain magnetic resonance imaging (MRIs) during this time showed no identifiable CNs abnormality. Full body positron emission tomography imaging and cerebrospinal fluid studies were normal. 5.25 years after initial sensory symptom onset, MRI showed new enhancement along the right mandibular branch of the trigeminal nerve with foramen ovale widening. Autopsy showed squamous cell carcinoma within both CNs sixth. A long interval to diagnosis of PNS is associated with high morbidity, emphasizing the need for earlier methods of detection when clinical suspicion is high.