Risk of Stroke After Nonarteritic Anterior Ischemic Optic Neuropathy

Stroke Risk Following Nonarteritic Anterior Ischemic Optic Neuropathy

Importance

The association between nonarteritic anterior ischemic optic neuropathy (NAION) and an increased risk of stroke has been a subject of debate. However, multinational studies on this topic are scarce.

Objective

To evaluate the short-term and long-term stroke risk after NAION compared with a matched control group.

Design, Setting, and Participants

This global, retrospective, population-based cohort study used aggregated electronic health records from January 1, 2004, through March 19, 2024, sourced from the Global Collaborative Network of TriNetX, which includes data from over 152 million patients across 17 countries. Patients in the study were followed up for a maximum duration of 10 years. Patients with NAION and age-related cataract were included in the analysis. Those with stroke before the diagnosis of NAION and age-related cataract were excluded. Propensity score matching was applied to balance age, sex, race, ethnicity, comorbidities, and medication use.

Exposure

International Statistical Classification of Diseases and Related Health Problems, Tenth Revision (ICD-10) diagnosis code for NAION or age-related cataract.

Main Outcomes and Measures

The primary outcome was the relative risk (RR) of stroke (ICD-10 code I60-63) in the NAION cohort vs the matched controls. Multivariable logistic regression analyses were applied to identify potential clinical factors associated with stroke within the NAION cohort.

Results

A total of 89 811 patients were identified in both the NAION (mean [SD] age, 57.2 [18.5] years; 38 678 men [43.1%]) and control (mean [SD] age, 57.0 [17.9] years; 40 014 men [44.6%]) cohorts after matching. The NAION cohort demonstrated a significantly higher all-stroke risk at all time points: 1 month (RR, 5.04; 95% CI, 4.41-5.78), 3 months (RR, 3.79; 95% CI, 3.40-4.21), 1 year (RR, 2.50; 95% CI, 2.32-2.70), 5 years (RR, 1.54; 95% CI, 1.45-1.63), and 10 years (RR, 1.33; 95% CI, 1.23-1.43). Sensitivity analysis in patients without comorbidities similarly revealed a significantly increased all-stroke risk across all intervals: 1 month (RR, 7.55; 95% CI, 4.74-12.03), 3 months (RR, 6.70; 95% CI, 4.48-10.04), 1 year (RR, 3.96; 95% CI, 2.94-5.34), 5 years (RR, 2.85; 95% CI, 2.18-3.72), and 10 years (RR, 1.68; 95% CI, 1.25-2.26). Among all the clinical factors of interest, only hypertension was consistently associated with all subtypes of stroke following NAION.

Conclusions and Relevance

This cohort study of patients with NAION found a significantly elevated risk of stroke compared with matched controls, independently of comorbidities. These findings underscore the importance of regular stroke workups following the onset of NAION.

Risk of Future Stroke in Patients with a Diagnosis of Peripheral Vertigo in the Emergency Department

BACKGROUND

We evaluated the temporal characteristics of stroke risks in the emergency department patients who had a diagnosis of peripheral vertigo. We also attempted to reveal the stroke risk factor among those with peripheral vertigo.

METHODS

This is a parallel group cohort study in a tertiary referral hospital. After assigning each of matched 4367 patients to the comparative set of peripheral vertigo and appendicitis-ureterolithiasis groups and each of matched 4911 to the comparative set of peripheral vertigo and ischemic stroke groups, we evaluated the relative stroke risk. In addition, to predict the individual stroke risk in patients with peripheral vertigo, any association between the demographic factors and stroke events was evaluated in the peripheral vertigo group.

RESULTS

The peripheral vertigo group had a higher stroke risk than the appendicitis-ureterolithiasis group (HR=1.73, 95% CI=1.18-2.55) but a lower risk than the ischemic stroke group (HR=0.30, 95% CI=0.24-0.37). The stroke risk of the peripheral vertigo group was just below that of small vessel stroke. The stroke risk of the peripheral vertigo group differed markedly by time: higher within seven days, moderate between seven days and one year, and diminished thereafter. Old age (>65), male gender, and diabetes mellitus were the risk factors for stroke in the peripheral vertigo group.

CONCLUSION

Patients with a diagnosis of peripheral vertigo in the ED showed a moderate future stroke risk so that requires a stroke preventive strategy tailored to the timing of symptom onset and individual risk.

Evaluation of hemodynamic changes in nonarteritic anterior ischemic optic neuropathy using multimodality imaging

Background

Nonarteritic anterior ischemic optic neuropathy (NAION) patients experience hypo-perfusion in the short posterior ciliary arteries (SPCAs), however, the cause of hypo-perfusion is unclear. Real-time dynamic hemodynamic observations may provide clues into specific NAION pathogenic mechanisms. We aim to analyze hemodynamic changes occurring in NAION using multimodality imaging. Our specific focus is identifying pathogenic mechanisms underlying SPCA insufficiency in NAION.

Methods

Three-dimensional arterial spin labeling (3D ASL) magnetic resonance imaging (MRI) and three-dimensional time-of-flight (3D-TOF) magnetic resonance angiography (MRA) were performed on 25 NAION patients (50 eyes) and 22 (44 eyes) normal cases were recruited. The diameter of the initial part of the ophthalmic artery and internal carotid artery siphon were measured using MRA. Blood vessel identification and blood flow (BF) were detected using 3D ASL MRI. We measured BF values of the optic nerve head (ONH) region of the retina/choroid complex, optic nerve (ON), temporal lobe, and occipital lobe.

Results

We studied 32 NAION affected eyes, 18 NAION uninvolved eyes, and 44 normal eyes. Diameter of the initial part of ophthalmic artery in the NAION affected eyes was significantly larger than the uninvolved eyes (P=0.026). Diameter of the NAION eyes was 1.33±0.19 mm [mean ± standard deviation (SD)], uninvolved eyes were 1.15±0.21 mm. At a photolabeling delay times (PLD) of 1,500 and 2,500 ms, BF of the ONH and ON in NAION affected eyes was significantly less than uninvolved and normal eyes (pONH <0.001 both at 1,500 and 2,500 ms, pON <0.001 and pON =0.001 at 1,500 and 2,500 ms, respectively). ONH of uninvolved eyes was also significantly less than normal eyes. Additionally, BF of the ONH region correlated with temporal lobe BF, with an R²=0.3231 and 0.2397 at 1,500 and 2,500 ms, respectively. BF of the ONH region also correlated with occipital lobe BF, with an R²=0.2534 and 0.4397 at 1,500 and 2,500 ms, respectively. ON and temporal lobe BF also correlated, with an R²=0.226 and 0.1504 at 1,500 and 2,500 ms, respectively.

Conclusions

Abnormal hemodynamics of small cerebral vessels existed prior to the onset of NAION. A candidate mechanism underlying NAION appears to be transient insufficiency of blood supply and decompensation of ocular vascular regulation.

Increased risk of cancer in patients with retinal vein occlusion: a 12-year nationwide cohort study

Aims

To investigate the association between incident retinal vein occlusion (RVO) and the subsequent development of cancer.

Methods

In this nationwide population-based retrospective study using 2002–2013 National Health Insurance Service database which covers the entire South Korean population, 186 701 incident RVO patients and their 1:1 propensity-score matched controls were included. We defined the fixed cohort from January 1st, 2004 to December 31st, 2013; the cohort included patients who suffered incident RVO after entering the cohort and their matched controls, and excluded patients having any cancer history before entering the cohort. The association of RVO and cancer was assessed by time-varying covariate Cox regression models; Model 1 included RVO as a time-varying covariate, Model 2 included Model 1 plus demographic information and Model 3 included Model 2 and comorbidities.

Results

RVO was associated with an increased risk of subsequent cancer (HR=1.29; 95% CI, 1.26–1.31 in Model 1), which was consistent in Models 2 and 3. The incidence rate of overall cancer during the study period was 25.55 (95% CI, 25.19–25.91) per 1000 person-years in the RVO group and 18.62 (95% CI, 18.46–18.79) per 1000 person-years in the control group. In the subgroup analysis, haematological malignancies showed the highest association with RVO (HR=1.65; 95% CI, 1.49–1.83).

Conclusion

Patients with RVO have an increased risk of subsequent cancer development even after adjusting for demographic factors and comorbidities. Further study is warranted to elucidate these associations to provide proper recommendations for RVO patients regarding the cancer screening.

Statins in Neuro-ophthalmology

Statins are effective and well-tolerated hypolipidaemic agents which have been increasingly studied for their pleiotropic immunomodulatory and anti-inflammatory effects. Statins have potential therapeutic benefit in a range of neuro-ophthalmological conditions but may also induce or exacerbate certain neurological disorders. This literature review examines evidence from clinical and in vitro studies assessing the effects of statins in myasthenia gravis, myopathy, multiple sclerosis, neuromyelitis optica, idiopathic intracranial hypertension (pseudotumour cerebri), migraine, giant cell arteritis, Bell's palsy, ocular ischaemia, stroke, Alzheimer's disease and Parkinson's disease.

Aggravation of Cerebral Ischemia/Reperfusion Injury by Peroxisome Proliferator-Activated Receptor-Gamma Deficiency via Endoplasmic Reticulum Stress

BACKGROUND Ischemic stroke is a dominant contributor to disability and mortality worldwide and is recognized as an important health concern. As a transcription factor triggered via stress, peroxisome proliferator-activated receptor-gamma (PPAR-γ) has a crucial impact on differentiation, cell death, and cell growth. However, the role of PPAR-γ and its precise mechanism in cerebral ischemia injury (CII) remain unclear. MATERIAL AND METHODS The male C57Bl/6 mice (12 weeks old, n=52) were subjected to middle cerebral artery occlusion (MCAO). Infarct volume was evaluated by 2, 3, 5-Triphenyltetrazolium chloride staining. Cell apoptosis was measured by terminal dUTP nick-end labeling (TUNEL) staining. The expression of apoptotic-related protein was examined by Western blotting. Neuron2A cells were transfected with PPAR-γ-specific siRNA and then were subjected to oxygen-glucose exhaustion and reoxygenation. RESULTS It was observed that PPAR-γ-deficient mice displayed extended infarct trigon in the MCAO stroke model. Neuronal deficiency was more severe in PPAR-γ-deficient models. Additionally, expression of cell death-promoting Bcl-2 associated X and active caspase-3 was reinforced, while that of cell death-counteracting Bcl-2 was repressed in PPAR-γ-deficient mice. This was characterized by reinforced endoplasmic reticulum (ER) stress reactions in in vivo brain specimens as well as in vitro neurons in ischemia/reperfusion (I/R) injury. CONCLUSIONS This research proved that PPAR-γ protected the brain from cerebral I/R injury by repressing ER stress and indicated that PPAR-γ is a potential target in the treatment of ischemia.