MedGen

Acute inflammation of the liver in humans; caused by hepatitis E virus, a non-enveloped single-stranded rna virus. Similar to hepatitis A, its incubation period is 15-60 days and is enterically transmitted, usually by fecal-oral transmission. [from MONDO]

The photoparoxysmal response (PPR), also referred to as photosensitivity, is defined as the abnormal occurrence of cortical spikes or spike and wave discharges on electroencephalogram (EEG) in response to intermittent light stimulation (Doose and Waltz, 1993). Photosensitivity is a frequent finding in patients with idiopathic generalized epilepsy (see 600669), especially those with juvenile myoclonic epilepsy, suggesting a common epileptogenic pathway for both phenomena. The comorbidity of the 2 disorders suggests that presence of PPR may also increase the risk for epilepsy (Stephani et al., 2004; Tauer et al., 2005). Genetic Heterogeneity of Photoparoxysmal Response The PPR1 locus has been mapped to chromosome 6p21. See also PPR2 (609572), mapped to chromosome 13q31, and PPR3 (609573), mapped to chromosome 7q32. [from OMIM]

A rare reflex epilepsy characterized by seizures and photoparoxysmal responses triggered by flashing or flickering lights, or patterns. Exact nature of the stimulus and seizure type are variable. The disorder mainly presents in childhood and adolescence and can either occur as an isolated condition, or be associated to other epilepsy syndromes. [from ORDO]