Diagnosis of<unk>  is by clinical impression and can sometimes be confirmed by a formal neuropsychological assessment.<unk>  encephalopathy typically presents with ataxia and nystagmus, and<unk> 's psychosis with anterograde and retrograde amnesia and confabulation upon relevant lines of questioning. Frequently, secondary to thiamine deficiency and subsequent cytotoxic edema in<unk>  encephalopathy, patients will have marked degeneration of the mammillary bodies. Thiamine (vitamin B1) is an essential coenzyme in carbohydrate metabolism and is also a regulator of osmotic gradient. Its deficiency may cause swelling of the intracellular space and local disruption of the blood-brain barrier. Brain tissue is very sensitive to changes in electrolytes and pressure and edema can be cytotoxic. In<unk>  this occurs specifically in the mammillary bodies, medial thalami, tectal plate, and periaqueductal areas. Sufferers may also exhibit a dislike for sunlight and so may wish to stay indoors with the lights off. The mechanism of this degeneration is unknown, but it supports the current neurological theory that the mammillary bodies play a role in various "memory circuits" within the brain. An example of a memory circuit is the Papez circuit. File:MRI FLAIR sequence<unk>  Encephalopathy.Axial MRI FLAIR image showing hyperintense signal in the mesial dorsal thalami, a common finding in<unk>  encephalopathy. This patient was nearly in coma when IV thiamine was started, he responded moderately well but was left with some<unk>  type deficits. File:MRI DWI sequence showing restricted diffusion in the mesial dorsal thalami.Axial MRI B=1000 DWI image showing hyperintense signal indicative of restricted diffusion in the mesial dorsal thalami. File:MRI FLAIR sequence showing hyperintense signal in the periaqueducal grey matter in<unk>  Encephalopathy.Axial MRI FLAIR image showing hyperintense signal in the periaqueductal gray matter and tectum of the dorsal midbrain.
Wernicke–Korsakoff syndrome
Hepatic encephalopathy
Sydenham's chorea
Catel–Manzke syndrome
Stratton Parker syndrome
Benedikt syndrome
Dejerine–Roussy syndrome
Parkinson-plus syndrome