All the London railway stations :
Essex Road is on ThamesLink, and is believed to not be accessible to wheelchair users to access platforms. See pictures and further accessible transport in London detail from links below.
National Rail : ThamesLink
Accessibility friendly : Partial. The map does not describe this station properly, although there is a lift. Contact the station before using Essex Road. No ramps onto trains available.
General description : See wiki
More comment : National Rail Guide & Maps