An alcoholic is brought to the Emergency OPD with the complaint of irrelevant talking. He had stopped using alcohol three days back. On examination, He is found to be disoriented to time, place and person. He also has visual illusions and hallucinations. There is no history of head injury. Most likely diagnosis is –

**Core Concept**
The underlying concept being tested is the clinical presentation of alcohol withdrawal syndrome, specifically the symptoms of delirium tremens (DTs). Delirium tremens is a severe form of alcohol withdrawal that occurs 48-72 hours after the last drink, characterized by altered mental status, hallucinations, and disorientation.

**Why the Correct Answer is Right**
The patient's symptoms of disorientation to time, place, and person, visual illusions, and hallucinations are classic features of delirium tremens. This condition is caused by a sudden cessation of alcohol consumption after prolonged heavy drinking, leading to a severe imbalance of neurotransmitters such as GABA and glutamate. The brain's attempt to compensate for the lack of GABA (an inhibitory neurotransmitter) results in an overactivation of glutamate (an excitatory neurotransmitter), causing the characteristic symptoms of delirium tremens.

**Why Each Wrong Option is Incorrect**
**Option A:** This option might be tempting, but the patient's symptoms do not suggest a simple case of intoxication or acute alcohol poisoning. Intoxication typically presents with slurred speech, impaired coordination, and altered mental status, but not the severe symptoms seen in this patient.

**Option B:** While the patient has altered mental status, the presence of visual illusions and hallucinations, along with the history of alcohol cessation, points away from a primary psychiatric diagnosis such as schizophrenia.

**Option C:** This option is incorrect because the patient's symptoms do not suggest a primary neurological diagnosis such as encephalitis or meningitis, which would typically present with fever, headache, and focal neurological deficits.

**Clinical Pearl / High-Yield Fact**
Delirium tremens is a medical emergency that requires immediate attention and treatment with benzodiazepines to prevent progression to more severe complications.

**Correct Answer: C. Delirium Tremens**

✓ Correct Answer: B. Delirium tremens