Clinically relevant increases in serum neurofilament light chain and glial fibrillary acidic protein in patients with Susac syndrome.

BACKGROUND AND PURPOSE: Serum levels of neurofilament light chain (sNfL) and glial fibrillary acidic protein (sGFAP) are promising neuro-axonal damage and astrocytic activation biomarkers. Susac syndrome (SS) is an increasingly recognized neurological condition and biomarkers that can help assess and monitor disease evolution are highly needed for the adequate management of these patients. sNfL and sGFAP levels were evaluated in patients with SS and their clinical relevance in the relapse and remission phase of the disease was assessed. METHODS: As part of a multicentre study that enrolled patients diagnosed with SS from six international centres, sNfL and sGFAP levels were assessed in 22 SS patients (nine during a relapse and 13 in remission) and 59 age- and sex-matched healthy controls using SimoaTM assay Neurology 2-Plex B Kit. RESULTS: Serum NfL levels were higher than those of healthy controls (p < 0.001) in SS patients and in both subgroups of patients in relapse and in remission (p < 0.001 for both), with significantly higher levels in relapse than in remission (p = 0.008). sNfL levels showed a negative correlation with time from the last relapse (r = -0.663; p = 0.001). sGFAP levels were slightly higher in the whole group of patients than in healthy controls (p = 0.046) and were more pronounced in relapse than in remission (p = 0.013). CONCLUSION: In SS patients, both sNFL and sGFAP levels increased compared with healthy controls. Both biomarkers had higher levels during clinical relapse and much lower levels in remission. sNFL was shown to be time sensitive to clinical changes and can be useful to monitor neuro-axonal damage in SS.

Focal Pachymeningitis Induced Papilloedema as an Early Manifestation of Relapsing Polychondritis.

A 52-year-old male patient presented with longstanding non-specific symptoms of ocular redness and irritation. Clinical examination not only revealed bilateral anterior scleritis but also bilateral optic disc swelling. Additional history taking revealed headaches and tinnitus, both starting around the same time as the eye redness, as well as a prior episode of swelling and redness of both ears. The lumbar puncture opening pressure was 29 cm of cerebrospinal fluid (CSF). There were 11 white blood cells/µl in the CSF. Subsequent magnetic resonance imaging showed focal thickening of the dura mater over the left cerebral convexity, suggestive of focal pachymeningitis. 18F-fluorodeoxyglucose positron emission tomography demonstrated hypermetabolic abnormalities located at the auricles, the nostrils, the anterior part of the eyes, and the dura mater over the left cerebral convexity, suggestive of relapsing polychondritis (RPC). RPC is a rare systemic immune-mediated condition; diagnosis can sometimes be delayed or missed due to insidious disease onset with non-specific symptoms. Nevertheless, sight-threatening or even life-threatening complications may occur. Given the high prevalence of ocular involvement, one should be suspicious when faced with patients with recurrent ocular inflammation. Optic disc swelling is a more uncommon finding, and while different mechanisms have been reported, it has rarely been associated with raised intracranial pressure. Nevertheless, intracranial hypertension arising from inflammation of the CSF and/or surrounding meninges caused by the newly diagnosed RPC was identified as the most likely underlying mechanism for the bilateral optic disc swelling in our patient.

Posterior segment spectral domain oct in the differential diagnosis of bilateral temporal optic neuropathy and its correlation with visual acuity.

PURPOSE: To identify the underlying etiologies and to evaluate the differential diagnostic value of posterior segment spectral domain OCT measurements and their correlation with best-corrected visual acuity (BCVA) in a group of patients with OCT documented bilateral optic neuropathy limited to the temporal quadrants. METHODS: Retrospective study. RESULTS: We included 61 patients: 35 presented with presumed "classic" acquired mitochondrial optic neuropathy (MON) (18 nutritional, 11 toxic, 6 mixed toxic-nutritional) and 2 with suspected hereditary MON. Nine patients were identified as 'MON mimickers' (especially multiple sclerosis), and 4 were found to have a mixed mechanism, while 11 remained undiagnosed. Across all etiologies, the strongest positive relationship between BCVA and tested OCT parameters was with macular GCL (ganglion cell layer) and GCIPL (combined ganglion cell and inner plexiform layer) volumes rather than peripapillary retinal nerve fiber layer (RNFL) thicknesses (all statistically significant). There was an inverse relationship between BCVA and inner nuclear layer (INL) volumes, with significant differences for BCVA and all tested OCT parameters between eyes with and without INL microcystoid lesions. OCT (absolute values and intereye differences) was not helpful in distinguishing between presumed acquired mitochondrial disease and patients with multiple sclerosis without optic neuritis. However, significantly greater intereye differences in global RNFL and inner plexiform layer and GCIPL volumes were found in patients with a previous history of unilateral optic neuritis. CONCLUSIONS: The strongest positive relationship with BCVA was found for macular GCL and GCIPL volumes. OCT could not differentiate between acquired mitochondrial disease and multiple sclerosis without optic neuritis.

EVALUATION OF TUMOR NECROSIS FACTOR INHIBITOR THERAPY IN SUSAC SYNDROME.

PURPOSE: To evaluate the effect of tumor necrosis factor (TNF) inhibitor therapy on ocular relapses in patients with Susac syndrome. METHODS: Multicenter retrospective cohort study of patients diagnosed with Susac syndrome according to classical clinical criteria. We evaluated the disease activity before and after introduction of anti-TNF therapy and its value as a steroid-sparing agent. RESULTS: Five patients were included. All were initially treated with a combination of corticosteroids and classical immunosuppressive drugs. Infliximab was started in three patients, and adalimumab was started in two patients. Patients had on average 5 ocular relapses during a mean follow-up time of 2.59 years before introducing a TNF inhibitor, corresponding with on average 1.93 relapses per year. After the introduction of an anti-TNF agent, this number was reduced by factor 5.51 to an average of 0.35 relapses per year for a mean follow-up of 2.86 years (P = 0.10). Before anti-TNF introduction ocular relapses occurred at a mean daily dose of 34 mg of prednisone, whereas with anti-TNF treatment, corticosteroid administration could be completely stopped in four patients with one patient still needing 5 mg daily (P = 0.10). Infliximab and adalimumab generally were well tolerated, and no serious adverse events were reported. CONCLUSION: Although not statistically significant, our results suggest that anti-TNF therapy can be a valuable option for the treatment of ocular Susac syndrome and may especially be considered in those patients unresponsive to more conventional immunosuppressive treatment.

Internal Carotid Artery Dissection Presenting with Transient or Subclinical Horner Syndrome.

Introduction: The most frequently encountered symptoms in internal carotid artery dissection (ICAD) are head or neck pain and cerebral ischemia. Ocular symptoms or signs have been reported as the presenting feature in up to 50% of patients, with (painful) Horner syndrome being the most frequently associated. Horner syndrome is part of the classic triad that depicts the characteristic presentation of ICAD and that consists of pain in the ipsilateral neck, head and orbital regions, (partial) Horner syndrome, and cerebral or retinal ischemia. All patients presenting with painful Horner syndrome should therefore require prompt investigations to rule out carotid artery dissection. In patients with confirmed diagnosis, treatment should be started early to prevent permanent ocular or cerebral complications. Case Presentation: Case 1: A 61-year-old woman presented with right temporal headache, an episode of transient visual loss and drooping of the right upper eyelid. Examination revealed anisocoria, which was more important in darkness. Reversal of anisocoria was observed after instilling drops of apraclonidine 0.5%. Neuroimaging demonstrated intrapetrous ICAD. Headaches, eyelid ptosis, and anisocoria all had resolved the next day. Apraclonidine pharmacologic testing a few weeks later was no longer dilating the previously smaller pupil. Case 2: A 48-year-old man presented with drooping of the right upper eyelid and right occipital headache and facial pain that all started one day after an intense yoga workout. Anisocoria was noticed upon examination, with topical cocaine 10% pharmacologic testing confirming a right Horner syndrome. Neuroimaging revealed ICAD. The patient reported resolution of his eyelid ptosis a few days later. Eyelid ptosis and anisocoria had indeed resolved at a follow-up examination a few weeks later. However, cocaine drop testing still produced anisocoria, compatible with subclinical Horner syndrome. Conclusion: Transient or subclinical Horner syndrome can be the presenting feature in ICAD; in such cases, the characteristic eyelid ptosis and anisocoria may be short-lived and resolve in only a few days. If suspected by clinical history, pharmacologic testing may be helpful in identifying subclinical cases.

Sarcoidosis revealed by simultaneous optic nerve and eyelid involvement: A case report.

PURPOSE: Ocular disease can be the initial manifestation in patients with sarcoidosis. It is most often associated with uveitis, but eyelid or optic nerve disease can also be presenting features. Although uncommon and easy to overlook in a patient presenting with visual loss, paying attention to the presence of eyelid granulomas in our patient proved to be very helpful in our diagnostic work up for optic neuropathy. OBSERVATIONS: A young otherwise healthy patient was addressed with a 3 month history of bilateral painless visual loss. At presentation, best-corrected visual acuity was counting fingers in both eyes. Anterior segment slit-lamp examination was completely normal in both eyes. Eye fundus examination revealed subtle optic disc swelling in the left eye. Interestingly, flesh-colored nodular eyelid lesions were found bilaterally. Basic work-up for optic neuropathy showed elevated levels of serum lysozyme and serum angiotensin converting enzyme. More importantly, a biopsy specimen of an eyelid nodule demonstrated multiple non-necrotizing granulomas, a hallmark sign of sarcoidosis. Despite a delay in treatment of several months after onset of symptoms, response to systemic corticosteroids was prompt and important with visual acuity improving to 20/20 in both eyes as well as complete resorption of all eyelid lesions. CONCLUSION AND IMPORTANCE: In the diagnostic work-up for optic neuropathy, the answer can sometimes be hiding where it's least expected: the possible presence of eyelid lesions should not be overlooked as they may orient us towards sarcoidosis as an underlying etiology.

Optic neuritis in lung adenocarcinoma: A challenging diagnosis.

Optic neuritis with CRMP-5 IgG is a paraneoplastic inflammation of the optic nerve associated with lung cancer, mostly small-cell lung cancer. We present the case of a patient with lung adenocarcinoma who developed progressive bilateral visual loss a few months after immune-chemotherapy with pembrolizumab and after Covid-19 vaccination. Positive CRMP-5 IgG were detected in blood sample and complete work-up - including brain MRI - did not show any progression. High dose systemic corticoids were administered with transient improving, followed by intravenous immunoglobulins, methotrexate and rituximab but despite negativization of CRMP-5 IgG, the patient had a progressive visual loss.

Central retinal artery occlusion and Susac syndrome: a case report.

BACKGROUND: Susac syndrome is a rare disease attributed to microangiopathy involving the arterioles of the brain, retina, and cochlea. Understanding the pathogenesis is incomplete, but an immune-mediated process remains the leading hypothesis. METHODS: Report of a single case of a previously healthy 22-year-old female patient showing the complete clinical triad. RESULTS: Diagnosis of Susac syndrome in this patient was first questioned due to the atypical initial ophthalmologic presentation with central retinal artery occlusion. Multiple relapses occurred in the fellow eye during follow-up, showing the typical branch retinal artery occlusions, allowing definite diagnosis. CONCLUSION: Susac syndrome should be considered in the differential diagnosis when facing (young) patients with central retinal artery occlusion, especially in the presence of unexplained encephalopathy and/or sensorineural hearing loss.