4; P = .04). (2) After adjusting for typical migraine aura, comparison of 17 “visual snow” patients with 17 age and gender matched controls showed brain hypermetabolism

in the right lingual gyrus (Montreal Neurological Institute coordinates 16-78-5; kE = 101; ZE = 3.41; P < .001) and the left cerebellar anterior lobe adjacent to the left lingual gyrus (Montreal Neurological Institute coordinates -12-62-9; kE = 152; ZE = 3.28; P = .001). Comorbid migraine aggravates the clinical phenotype of the “visual snow” syndrome by worsening some of the additional visual symptoms and tinnitus. This might bias studies on “visual snow” by migraineurs offering study participation more likely than non-migraineurs due to a more severe clinical presentation. The independence of entoptic phenomena from comorbid migraine indicates “visual www.selleckchem.com/products/Cilomilast(SB-207499).html snow” is the main determinant. The hypermetabolic lingual gyrus confirms a brain dysfunction in patients with “visual snow.” The metabolic pattern differs from interictal migraine with some similarities

to migrainous photophobia. The findings support the view that “visual snow,” migraine, and typical migraine aura are distinct syndromes with shared pathophysiological mechanisms that need to be addressed in order to develop rational treatment strategies for this disabling condition. selleck screening library Patients with “visual snow” (VS) describe a visual disturbance that consists of tiny dynamically flickering dots in the entire visual field resembling the “static” or “snow” of a badly tuned analogue television. The symptoms are continuous and can persist over years. Persistent visual disturbance is mentioned sporadically in the literature without larger systematic studies.1-3 Patients are often diagnosed as having persistent migraine aura, malingering, or psychogenic disorder because objective measures for the condition are not available to date. A recent study of a substantial cohort of subjects with VS confirmed that the visual disturbance is often associated with migraine

and migraine aura. However, not every patient with VS has a history of migraine. Further, VS starts only rarely with migraine aura, and the phenotypical description as well as the clinical course of VS by no means resembles typical migraine aura, which is in general homonymous, often presents with MCE公司 moving zigzag lines, and typically lasts less than 60 minutes. This suggests that VS is a unique condition different from migraine aura.4-6 Importantly, VS should be seen as a syndrome since it is almost always associated with additional visual complaints including palinopsia, entoptic phenomena that arise from the optic apparatus itself (ie, floaters, blue field entoptic phenomenon, self-light of the eye and photopsia),[7] poor night vision (nyctalopia), and photophobia. A large proportion of VS patients has bilateral continuous tinnitus.