Neurophysiologic Monitoring of Oculomotor Nerves During Transorbital Surgery: Proof of Concept and Anatomic Demonstration.

BACKGROUND AND OBJECTIVES: Transorbital neuroendoscopic surgery (TONES) is continuously evolving and gaining terrain in approaching different skull base pathologies. The objective of this study was to present our methodology for introducing recording electrodes, which includes a new transconjunctival pathway, to monitor the extraocular muscle function during TONES. METHODS: A translational observational study was performed from an anatomic demonstration focused on the transconjunctival electrode placement technique to a descriptive analysis in our series of 6 patients operated using TONES in association with intraoperative neurophysiologic monitoring of the oculomotor nerves from 2017 to 2023. The stepwise anatomic demonstration for the electrode placement and correct positioning in the target muscle was realized through cadaveric dissection. The descriptive analysis evaluated viability (obtention of the electromyography in each cranial nerve [CN] monitored), security (complications), and compatibility (interference with TONES). RESULTS: In our series of 6 patients, 16 CNs were correctly monitored: 6 (100%) CNs III, 5 (83.3%) CNs VI, and 5 (83.3%) CNs IV. Spontaneous electromyography was registered correctly, and compound muscle action potential using triggered electromyography was obtained for anatomic confirmation of structures (1 CN III and VI). No complications nor interference with the surgical procedure were detected. CONCLUSION: The methodology for introducing the recording electrodes was viable, secure, and compatible with TONES.

Predictive value of retinal atrophy for cognitive decline across disease duration in multiple sclerosis.

BACKGROUND: We investigated the association between changes in retinal thickness and cognition in people with MS (PwMS), exploring the predictive value of optical coherence tomography (OCT) markers of neuroaxonal damage for global cognitive decline at different periods of disease. METHOD: We quantified the peripapillary retinal nerve fibre (pRFNL) and ganglion cell-inner plexiform (GCIPL) layers thicknesses of 207 PwMS and performed neuropsychological evaluations. The cohort was divided based on disease duration (≤5 years or >5 years). We studied associations between changes in OCT and cognition over time, and assessed the risk of cognitive decline of a pRFNL≤88 µm or GCIPL≤77 µm and its predictive value. RESULTS: Changes in pRFNL and GCIPL thickness over 3.2 years were associated with evolution of cognitive scores, in the entire cohort and in patients with more than 5 years of disease (p<0.01). Changes in cognition were related to less use of disease-modifying drugs, but not OCT metrics in PwMS within 5 years of onset. A pRFNL≤88 µm was associated with earlier cognitive disability (3.7 vs 9.9 years) and higher risk of cognitive deterioration (HR=1.64, p=0.022). A GCIPL≤77 µm was not associated with a higher risk of cognitive decline, but a trend was observed at ≤91.5 µm in PwMS with longer disease (HR=1.81, p=0.061). CONCLUSIONS: The progressive retinal thinning is related to cognitive decline, indicating that cognitive dysfunction is a late manifestation of accumulated neuroaxonal damage. Quantifying the pRFNL aids in identifying individuals at risk of cognitive dysfunction.

Progression of Retinal Ganglion Cell and Nerve Fiber Layer Loss in Spinocerebellar Ataxia 3 Patients.

Spectral domain optical coherence tomography (SD-OCT) allows noninvasive measurements of retinal neuron layers. Here, we evaluate the relationship between clinical features and anatomical SD-OCT measurements in patients with spinocerebellar ataxia type 3 (SCA3) and how they change with time. A retrospective review was conducted on SCA3 patients. Clinical variables such as disease duration, number of CAG repeats, and the Scale for the Assessment and Rating of Ataxia (SARA) score were correlated with SD-OCT measurements, including retinal nerve fiber layer (RNFL) thickness, ganglion cell complex (GCC) thickness, macular volume (MV), and central macular thickness (CMT). Seventeen SCA3 patients with an average follow-up of 44.9 months were recruited. Clinical features with significant baseline correlations with SD-OCT measurements included disease duration (CMT r = - 0.590; GCC r = - 0.585), SARA score (CMT r = - 0.560; RNFL r = - 0.390), and number of CAG repeats (MV r = - 0.552; RNFL r = - 0.503; GCC r = - 0.493). The annual rate of change of the SARA score during follow-up was associated with that of both the MV (r = - 0.494; p = 0.005) and GCC thickness (r = - 0.454; p = 0.012). High disability (stages 2 and 3) was independently inversely associated with the annual change in MV (ß coefficient - 17.09; p = 0.025). This study provides evidence of an association between clinical features and objective anatomical measurements obtained by SD-OCT in SCA3 patients. MV and GCC thickness could serve as potential biomarkers of disease severity, as their rates of decrease seem to be related to a worsening in the SARA score. These findings highlight the potential of SD-OCT as a noninvasive tool for assessing disease severity and progression in SCA3 patients.

Paraneoplastic orbital myositis as a first manifestation of renal cell carcinoma.

Paraneoplastic syndromes (PNSs) are remote effects of the primary tumor on tissues and organs, not related to direct invasion or metastasis. Ophthalmological involvement has been reported in 0.01-0.1% cases of PNSs. It may present as retinopathy, optic neuritis, myasthenia-like syndromes, or orbital myositis (OM), among others. An 89-year-old male with bilateral ocular pain and chemosis, was given an initial diagnosis of bilateral acute conjunctivitis. After 5 days, the patient presented worsening of the pain and bilateral complete ophthalmoplegia. Cranial CT scan showed diffuse bilateral thickening of the four rectus muscles. Inflammatory markers, thyroid hormones, and thyroid antibodies were normal. An abdominal ultrasound test was performed, observing a mass in the right kidney. After confirmation of the lesion with a CT scan, the radiological characteristics of the lesion were highly suggestive of renal cell carcinoma. Treatment with intravenous corticosteroids was ensued with complete resolution of all ophthalmological symptoms. Paraneoplastic orbital panmyositis was first described in 1994. Since then it has been reported scarcely, remaining an extremely rare entity. To our knowledge, this is the first report of its association with renal cell carcinoma. In the absence of inflammatory or dysthyroid blood markers, bilateral orbital panmyositis warrants further investigation for a possible underlying oncological pathology.

Ocular neuromyotonia of the right third cranial nerve.

Ocular neuromyotonia is a rare disorder of the oculomotor nerves caused by chronic damage to the nerve, usually secondary to previous irradiation or longstanding compression. We present the case of a 40-year-old man who had received proton beam therapy for a right cavernous sinus chondrosarcoma 15 years earlier. He developed intermittent episodes of self-limited horizontal diplopia, which occurred over the course of 1 year. At its peak, the deviation reached 20Δ in primary gaze and 25Δ in right gaze. Signs included right upper lid retraction and right medial rectus muscle absence of relaxation after sustained left gaze, with mild deficit of elevation and depression but no pupillary involvement. Full recovery occurred after he closed his eyes. Ocular neuromyotonia of the right oculomotor nerve was diagnosed after recurrence of primary disease relapse was ruled out. Symptoms remitted completely under oxcarbazepine.

La esclerosis múltiple en oftalmología: más allá de la neuritis óptica / Multiple sclerosis in ophthalmology: beyond optic neuritis

Las alteraciones del sistema visual son uno de los principales rasgos de la esclerosis múltiple (EM) y conllevan un gran impacto en la calidad de vida de los pacientes. Aunque la neuritis óptica es la manifestación más frecuente, existen otros procesos oftalmológicos no relacionados con la neuritis, cuyo conocimiento es de gran utilidad en el manejo de los pacientes con EM. Se describen estas anomalías agrupadas en alteraciones de las vías aferente y eferente, así como de áreas cerebrales superiores. Adicionalmente, se describen los principales efectos oftalmológicos secundarios de los fármacos actualmente empleados en el control de la EM

Disorders of the visual system are one of the main features of multiple sclerosis (MS), and have a great impact on the quality of life of patients. Although optic neuritis is the most frequent manifestation, there are other ophthalmological processes not related to neuritis, a knowledge of which is very useful in the management of patients with MS. These abnormalities are described, grouped into impairments of the afferent pathway, efferent pathway, or upper cerebral areas. Additionally, the main ophthalmological side effects of the drugs currently used in the control of MS are described

Multiple sclerosis in ophthalmology: beyond optic neuritis. / La esclerosis múltiple en oftalmología: más allá de la neuritis óptica.

Disorders of the visual system are one of the main features of multiple sclerosis (MS), and have a great impact on the quality of life of patients. Although optic neuritis is the most frequent manifestation, there are other ophthalmological processes not related to neuritis, a knowledge of which is very useful in the management of patients with MS. These abnormalities are described, grouped into impairments of the afferent pathway, efferent pathway, or upper cerebral areas. Additionally, the main ophthalmological side effects of the drugs currently used in the control of MS are described.

Intravitreal ranibizumab for choroidal neovascularization secondary to pathological myopia: 12-month follow-up.

PURPOSE: To evaluate the efficacy and safety of intravitreal ranibizumab in the treatment of choroidal neovascularization (CNV) due to pathological myopia (PM). METHODS: This retrospective case series studied outcomes in patients with CNV secondary to PM who were treated with intravitreal ranibizumab. Patients underwent complete ophthalmic evaluation, which included best-corrected visual acuity testing measured with Early Treatment Diabetic Retinopathy Study charts, optical coherence tomography (OCT) and baseline fluorescein angiography (FA). Indications for retreatment included the persistence of subretinal fluid on OCT as well as hemorrhages and new CNV on FA. Patients were followed for a minimum of 12 months. RESULTS: We treated 29 eyes in 29 patients; the mean age was 56.8 years. Thirteen eyes were naïve, while 16 had been previously treated with photodynamic therapy or intravitreal bevacizumab. The mean initial visual acuity was 44.8 letters; at the 12-month follow-up, it was 53.7 letters. The mean OCT foveal thickness decreased by 35.3 µm. Patients received an average of 1.38 injections. Statistically significant differences were observed both in visual acuity and in central foveal thickness. All subgroups had favorable outcomes. None of the patients developed injection-induced complications or drug-related side effects. CONCLUSION: Intravitreal injection of ranibizumab appears to be safe and efficacious in patients with CNV secondary to PM followed over a 12-month period.