I. Using the VINDICATED MEN mnemonic
Vessels (flow):
In the head and brain:
TIA, Stroke/intracranial hemorrhage; Brain stem stroke
Heart failure (poor perfusion)
Liver failure (encephalopathy). (lack of flow)
Renal failure (uremic encephalopathy), (lack of flow)
Fecal impaction, urinary retention (lack of flow).
Hypertensive encephalopathy
Rest of the body: MI, PE, anemia, porphyria, etc.
Infection + Inflammation:
In the head and brain:
Meningitis, encephalitis,
HIV, herpes, neurosyphilis
Sepsis, serious illness.
Hypotension
Heat stroke
Rest of the body: pneumonia, UTI, skin ulcers, sepsis, shock
Neoplasm: Primary brain mass or metastasis from the rest of the body
Drugs and Diet: Drug effect or withdrawal
Drug overdose
Alcohol, benzos, narcotics, SSRI, antipsychotics, anticholinergics, Digoxin, antihistamines, muscle/bladder relaxants; especially in the elderly, even in low doses. Drugs also include toxins and heavy metals.
Serotonin syndrome
Neuroleptic malignant syndrome (NMS)
Diet: Underhydration/undernutrition: Dehydration/poor oral intake/NPO
Iatrogenic / idiopathic:
Congenital:
Autoimmune: Autoimmune diseases with effects on the brain.
Trauma: Trauma to the head or body. Head injury.
Endocrine and Metabolic:
Hypoglycemia, hyperglycemia; hyperglycemic hyperosmolar state; diabetic ketoacidosis
Thyroid disease; Myxedema
Adrenal disease
Post-operative state
Electrolyte abnormality and renal function: Na+, K+, Ca+, Mg++, BUN/Cr, NH3+ etc.
Hypoxia
CO2 narcosis
Deficiencies and Excesses:
B12 deficiency
Folate deficiency
Thiamine deficiency
Environmental factors:
Malfunction or lack of assistive devices or steps: hearing aids, eyeglasses, contact lenses, sleep/wake cycle, immobilization).
Carbon monoxide
Burns
Hypothermia
Hyperthermia
Neuropsychiatric:
Neurologic disorders
Dementia, etc.
Seizure (Nonconvulsive status epilepticus)
Post-ictal state
Psychiatric disorders
Sleep disturbance,
Psychosis.
Emotional (e.g. anxiety, pain),
Postpartum psychosis.
II. Using the DELIRIUMS mnemonic
DELIRIUMS mnemonic.
Thinking through the Differential Diagnosis
When possible, you can divide the body into two anatomic locations. The head and brain vs. rest of the body. Then divide each of the parameters of the VINDICATED MEN mnemonic into central causes (in the head and brain) vs. peripheral causes (in the rest of the body).