No abstract

The pathogenic mechanism of MG following WNV remains uncertain. We hypothesize that WNV-triggered autoimmunity breaks immunological self-tolerance to initiate MG, possibly through molecular mimicry between virus antigens and AChR subunits or other autoimmune mechanisms.

To assess the potential role of Swedish Interactive Thresholding Algorithm (SITA) Fast computerized static perimetry, compared with that of Goldmann manual kinetic perimetry (GVF), for reliably detecting visual field defects in neuro-ophthalmic practice. Background: Automated visual field testing is challenging in patients with poor visual acuity or severe neurological disease. In these patients, GVF is often the preferred visual field technique, but performance of this test requires a skilled technician, and this option may not be readily available. The recent development of the SITA family of perimetry has allowed for shorter automated perimetry testing time in normal subjects and in glaucoma patients. However, its usefulness for detecting visual field defects in patients with poor vision or neurological disease has not been evaluated. Design and Methods: We prospectively studied 64 consecutive, neuro-ophthalmologically impaired patients with neurologic disability of 3 or more on the Modified Rankin Scale, or with visual acuity of 20/200 or worse in at least one eye. Goldmann manual kinetic perimetry and SITA Fast results were compared for each eye, with special attention to reliability, test duration, and detection and quantification of neuro-ophthalmic visual field defects. We categorized the results into 1 of 9 groups based on similarities and reliabilities. Patient test preference was also assessed. Results: Patients were separated into 2 groups, those with severe neurologic deficits (n=50 eyes) and those with severe vision loss but mild neurologic dysfunction or none at all (n = 50 eyes). Overall, GVF and SITA Fast were equally reliable in 77% of eyes. Goldmann manual kinetic perimetry and SITA Fast showed similar visual field results in 75% of all eyes (70% of eyes of patients with severe neurologic deficits and 80% of eyes with poor vision). The mean±SD duration per eye was 7.97±3.2 minutes for GVF and 5.43±1.41 minutes for SITA Fast (PϽ.001). Ninety-one percent of patients preferred GVF to SITA Fast. Conclusions: We found the SITA Fast strategy of automated perimetry to be useful in the detection, and accurate in the quantification of central visual field defects associated with neuro-ophthalmic disorders. Our results suggest that for the general ophthalmologist or neurologist, visual field testing with SITA Fast perimetry might even be preferable to GVF, especially if performed by a marginally trained technician, even in patients with severely decreased vision or who are neurologically disabled.

The diagnosis of patients with visual symptoms can be challenging and often requires in-depth knowledge of neuroanatomy that is well depicted by various imaging methods. Neurologists are expected to be familiar with the latest imaging techniques that play an important role not only in diagnosing diseases but also in determining disease pathogenesis. Close collaboration with the neuroimager, ophthalmologist, and, when available, neuro-ophthalmologist, is recommended when caring for patients with visual symptoms.

Ocular or eye pain is a frequent complaint encountered not only by eye care providers but neurologists. Isolated eye pain is non-specific and non-localizing; therefore, it poses significant differential diagnostic problems. A wide range of neurologic and ophthalmic disorders may cause pain in, around, or behind the eye. These include ocular and orbital diseases and primary and secondary headaches. In patients presenting with an isolated and chronic eye pain, neuroimaging is usually normal. However, at the beginning of a disease process or in low-grade disease, the eye may appear "quiet," misleading a provider lacking familiarity with underlying disorders and high index of clinical suspicion. Delayed diagnosis of some neuro-ophthalmic causes of eye pain could result in significant neurologic and ophthalmic morbidity, conceivably even mortality. This article reviews some recent advances in imaging of the eye, the orbit, and the brain, as well as research in which neuroimaging has advanced the discovery of the underlying pathophysiology and the complex differential diagnosis of eye pain.