Long-term prognosis of transient lone bilateral blindness in adolescents and young adults

Migraine: mimics, borderlands and chameleons

Diagnostically, headache is the easy part of migraine. It is the surrounds of migraine--the aura, prodrome and postdrome--that can be most challenging, and confused with other pathologies. This article examines the definition and variants of migraine; alternative diagnoses for which migraine may be mistaken (mimics); conditions that lie between migraine and other diagnoses (borderlands) and the possible presentations of migraine posing as other conditions (chameleons). The focus is on adults, with only passing reference to children. Migraine is more often a chameleon than a mimic; and it is the careful history that usually makes the distinction. Given migraine's prevalence of 10-15%, relatively uncommon features of migraine occur quite often, in comparison with frequent manifestations of less common diseases. Thus, even rare or under-recognised presentations of migraine come into the differential diagnosis of many presentations.

Exercise-induced visual loss associated with advanced glaucoma in young adults

PURPOSE

To highlight the phenomenon of exercise-induced visual loss associated with advanced glaucoma and to discuss the possible underlying mechanisms.

METHODS

Three young adult patients with congenital or juvenile-onset glaucoma presenting with visual loss which occurred during exercise underwent ophthalmic examination. In 2 cases, visual function parameters, including visual fields (Humphrey full threshold perimetry) were measured before and after exercise.

RESULTS

All patients clearly described visual loss during exercise. In the 2 cases in which data were available, significant impairment in central visual acuity and reduced foveal sensitivity and mean deviation on visual field analysis occurred during exercise of mild to moderate intensity with complete or near complete recovery of visual function upon cessation of exercise.

CONCLUSION

Young patients with advanced glaucomatous optic neuropathy should be questioned regarding exercise-induced visual disturbance. We hypothesise that a 'vascular steal' is the likely mechanism underlying this phenomenon. Patients should be advised to limit activities which induce their symptoms, and therapeutic measures to promote ocular blood flow should be considered.