Bilateral oculomotor ocular neuromyotonia: a case report.

BACKGROUND: Ocular neuromyotonia (ONM) is characterized by episodic diplopia, which is usually triggered by prolonged eccentric gaze of the affected extraocular muscles. The spell is characterized by involuntary, occasionally painful, sustained contraction of one or more extraocular muscles innervated by the oculomotor, trochlear, or abducens nerve. ONM usually occurs as a late consequence of radiotherapy around the parasellar area, although idiopathic cases have been reported. Most cases are unilateral; however, bilateral ONM has occasionally been described. CASE PRESENTATION: A 60-year-old woman presented with a 4-month history of episodic, painful, horizontal binocular diplopia. She underwent external beam radiotherapy to the skull base for treatment of nasopharyngeal carcinoma. The tumor was well controlled. General neurological examination findings were unremarkable. Neuro-ophthalmic examination revealed normal visual acuity, visual fields, pupils, and fundi. Ocular alignment showed orthotropia with normal ocular motility. Myasthenic eyelid signs were absent. However, she developed episodes of involuntary sustained contraction of the medial rectus muscle following prolonged eccentric gaze toward the affected medial rectus muscle, which resulted in esotropia upon returning to the primary position. The esotropic episodes spontaneously resolved after approximately 2 min. These spells affected both medial rectus muscles. Both pupils remained normal throughout the examination. Magnetic resonance imaging revealed neither brain parenchyma/brain stem lesions nor tumor recurrence. Her symptoms were successfully treated with carbamazepine. CONCLUSIONS: Episodic esotropia in the adducting eye following prolonged horizontal eccentric gaze is a significant characteristic of ONM affecting the bilateral medial rectus muscles (i.e., bilateral oculomotor ONM). In spite of its extreme rarity, ONM should be considered as a differential diagnosis of episodic diplopia, especially in patients with a history of radiotherapy around the parasellar area. Careful examination with prolonged eccentric gaze should be performed to achieve a correct diagnosis and avoid an extensive unnecessary workup.

Health-related quality of life of daily-life-affected benign essential blepharospasm: Multi-center observational study.

PURPOSE: To compare Thais' health-related quality of life (HRQOL) and severity grading, efficacy and safety in daily-life-affected benign essential blepharospasm (BEB) patients at baseline and after Botulinum toxin type A (BTX-A) treatment. DESIGN: Prospective-observational study. PARTICIPANTS: BEB patients with Jankovic rating scale (JRS) at least 3 in both severity and frequency graded from 14 institutes nationwide were included from August 2020 to June 2021. METHODS: Demographic data, HRQOL evaluated by the Thai version of EQ-5D-5L and NEI-VFQ-25 questionnaires, and severity grading score evaluated by Jankovic rating scale (JRS) at baseline, 1, and 3 months after the treatment were collected. The impact of the BTX-A injections and their complications were recorded. RESULTS: 184 daily-life-affected BEB patients were enrolled; 159 patients (86.4%) had complete data with a mean age of 61.40±10.09 years. About 88.05% were female, and 10.1% were newly diagnosed. Most of the patients had bilateral involvement (96.9%) and 12.6% had history of BEB-related accident. After BTX-A treatment, HRQOL improved significantly in 4 dimensions of EQ-5D-5L, except self-care. The EQ_VAS (mean±SD) was 64.54±19.27, 75.13±15.37, 73.8±15.85 (p<0.001) and EQ-5D-5L utility score was 0.748±0.23, 0.824±0.19 and 0.807±0.19 at baseline, 1, 3 months after treatment, respectively. From NEI-VFQ-25, HRQOL also improved in all dimensions, except eye pain. The JRS improved in all patients. Self-reported minor adverse events were 22.6%, which mostly resolved within the first month. CONCLUSION: Daily-life-affected BEB impacted HRQOL in most dimensions from both generic and visual-specific questionnaires. BTX-A treatment not only decreased disease severity, but also improved quality of life.

Etiologies of Acute Optic Neuritis in Thailand: An Observational Study of 171 Patients.

PURPOSE: To analyze the demographic patterns, clinical characteristics and etiologies of acute optic neuritis (ON). METHODS: This retrospective observational study included patients with acute ON who presented to a university hospital in Bangkok, Thailand, between January 2010 and March 2020. The demographic details, clinical characteristics and etiologies of acute ON were evaluated. RESULTS: A total of 171 patients were included in the study (78.4% [n=134] female; mean age 45 years [standard deviation 15.4 years]; 32.2% [n=55] bilateral involvement). The most common type of acute ON was idiopathic (51.5%), followed by neuromyelitis optica spectrum disorder (NMOSD, 30.9%), other autoimmune disorders (9.9%), myelin oligodendrocyte glycoprotein antibody-associated disorder (MOGAD, 5.3%), multiple sclerosis (MS, 1.8%), and postinfection (0.6%). In the other autoimmune disorders group, 2 patients developed systemic lupus erythematosus (1.2%), 2 Sjogren's syndrome (1.2%), 1 RA (0.6%), 1 anti-NMDAR (0.6%), 3 anti-Jo1 (1.8%), 2 c-ANCA (1.2%), 1 anti-centromere (0.6%), and 5 nonspecific autoimmune disorders (2.9%). In the idiopathic group, 38.6% developed single isolated ON, 1.8% relapsing isolated ON and 11.1% chronic relapsing inflammatory optic neuropathy. CONCLUSION: The most common form of acute ON in this study, similar to other Asian countries, was idiopathic. Idiopathic-ON shared some phenotypes with NMOSD and MOGAD. We also reported patients with anti-NMDAR, anti-Jo1, c-ANCA and anti-centromere disorders. Improvements in antibody detection have widened the range of possible etiologies of acute ON. The study highlighted the important role of antibodies in creating effective treatments in the future.