Patients with comparable degree of neuropathology could show different cognitive impairments. This could be explained with the concept of cognitive reserve (CR), which includes a passive and an active component. In particular, CR is used to explain the gap between tissue damage and clinical symptoms that has been observed in dementia and, in particular, in patients affected by Alzheimer disease (AD). Different studies confirm brain neuroplasticity. Our preliminary study demonstrated that AD patients with high education showed a CR inversely associated with glucose uptake measured in fluorodeoxyglucose positron emission tomography (FDG-PET), whereas the inverse correlation was observed in AD patients with low education. In other words, our findings suggest that CR compensates the neurodegeneration and allows the maintenance of patients’ cognitive performance. Best understanding of the concept of CR could lead to interventions to slow cognitive aging or reduce the risk of dementia.

Background: Bilateral optic neuritis is a rare condition generally associated with inflammatory, demyelinating, or toxic causes. Its association with glyphosate exposure has rarely been documented. Case Presentation: A 66-year-old man with hypertension, hypercholesterolemia, and hypothyroidism developed rapid bilateral vision loss within hours after acute inhalational exposure to glyphosate during agricultural work. MRI showed bilateral optic nerve hyperintensity consistent with optic neuritis. Cerebrospinal fluid and serum anti-NMO antibody tests were negative, while visual evoked potentials demonstrated increased latencies. High-dose corticosteroid therapy led to progressive clinical improvement. At follow-up, MRI revealed no new lesions and the patient experienced near-complete visual recovery. Conclusion: This case suggests a possible link between acute glyphosate exposure and reversible bilateral optic neuritis. Early recognition and corticosteroid therapy may support full functional recovery even in severe presentations.