People who survive an intoxication episode may develop persistent health problems. This group of persistent health symptoms are called syndrome of irreversible lithium-effectuated neurotoxicity (SILENT). The syndrome presents with irreversible neurological and neuro-psychiatric effects. The neurological signs are cerebellar dysfunction, extrapyramidal symptoms, and brainstem dysfunction. The neuro-psychiatric findings present with memory deficits,  cognitive deficits, and sub-cortical dementia. For a diagnosis, the syndrome requires the absence of prior symptoms and persistence of symptoms for greater than 2 months after cessation of lithium.