Stroke (Ischemic or Hemorrhagic): The acute onset of confusion, slurred speech, and weakness are classic signs of a stroke. The presence of these symptoms, especially in a middle-aged man, makes stroke a highly probable diagnosis. The fact that no facial droop is noted does not rule out a stroke, as the presentation can vary depending on the area of the brain affected.

Seizure or Post-Ictal State: The confusion and slurred speech could be indicative of a seizure or the post-ictal phase following a seizure. The inability to give a history or follow commands supports this possibility.
Hypoglycemia: Given the diaphoretic skin and the presence of a device with a connecting white wire (possibly an insulin pump), hypoglycemia is a plausible diagnosis. Hypoglycemia can cause confusion, slurred speech, and weakness.
Infection (Meningitis or Encephalitis): Although less likely given the stable vitals and lack of specific signs like fever or neck stiffness, infections affecting the central nervous system can present with acute confusion and altered mental status.

Hyperglycemic Hyperosmolar Nonketotic Syndrome (HHNS) or Diabetic Ketoacidosis (DKA): These conditions, associated with diabetes, can present with altered mental status, weakness, and are potentially life-threatening if not promptly addressed. The device on the hand suggests a possible diabetic condition.
Wernicke's Encephalopathy: This is a medical emergency caused by thiamine deficiency, often seen in alcoholics, but can also occur in other conditions leading to malnutrition. It presents with confusion, ataxia, and ophthalmoplegia, and is crucial to diagnose early to prevent long-term brain damage.
Subarachnoid Hemorrhage: Although the ECG was normal, a subarachnoid hemorrhage can cause sudden onset of confusion and altered mental status. It's a critical diagnosis not to miss due to its high mortality and morbidity.

Creutzfeldt-Jakob Disease: A rare, degenerative, fatal brain disorder that can present with rapid deterioration of mental and physical abilities, including confusion and speech difficulties.
Hashimoto's Encephalopathy: A rare condition associated with Hashimoto's thyroiditis, presenting with altered mental status, confusion, and can mimic other neurological conditions.
Reversible Posterior Leukoencephalopathy Syndrome (PRES): A rare condition characterized by headache, confusion, seizures, and visual disturbances, often associated with hypertension and certain medications.