A 60-year-old man is found roaming aimlessly by a shopkeeper and brought him to the hospital. He was unable to tell his address. The blood investigation assay revealed: Na+115 mEq/L, K+ 3.2 mEq/L. Which of the following is the most likely diagnosis?

Ans. B DeliriumDelirium, also known as acute confusional state, is an organically caused decline from a previous baseline level of mental function that develops over a short period of time, typically hours to days. Delirium is a syndrome encompassing disturbances in attention, consciousness, and cognition. It may also involve other neurological deficits, such as psychomotor disturbances (e.g. hyperactive, hypoactive, or mixed), impaired sleep-wake cycle, emotional disturbances, and perceptual disturbances (e.g. hallucinations and delusions), although these features are not required for diagnosis. Delirium is caused by an acute organic process, which is a physically identifiable structural, functional, or chemical problem in the brain that may arise from a disease process outside the brain that nonetheless affects the brain. It may result from an underlying disease process (e.g. infection, hypoxia, dehydration, electrolyte imbalance), side effect of a medication, withdrawal from drugs, over-consumption of alcohol, or from any number of factors affecting one's overall health (e.g. malnutrition, pain, etc.). In contrast, fluctuations in mental status/function due to changes in primarily psychiatric processes or diseases (e.g. schizophrenia, bipolar disorder) do not, by definition, meet the criteria for 'delirium.'