Etiologies of Decreased Responsiveness

see: Differential Diagnosis of Delirium

1° Neurologic (usually with focal signs)

  • Vasc: ischemic stroke/TIA, ICH, VST, PRES, vasculitis, pituitary apoplexy
  • Seizure: postictal, status, nonconvulsive
  • Infxn: meningitis, encephalitis, abscess
  • Trauma: TBI, concussion, diffuse axonal injury
  • ↑ intracranial pressure: mass, edema, hydrocephalus, herniation
  • Autoimmune/paraneoplastic enceph.
  • Neurodeg: late-stage (eg, Alzheimer’s) or rapidly progressive (eg, CJD)

Systemic (esp. in elderly or prior CNS injury)

  • Cardiac: global ischemia, HoTN, HTN enceph
  • Pulmonary: ↓ PaO2, ↑ PaCO2
  • GI: liver failure, ↑ NH3
  • Renal: uremia, dialysis, ↓ or ↑ Na, ↓ or ↑ Ca
  • Heme: TTP/HUS, DIC, hyperviscosity
  • Endo: ↓ glc, DKA/HHNS, hypothyr., Addisonian
  • ID: pneumonia, UTI, endocarditis, sepsis
  • Hypothermia & hyperthermia
  • Meds: anticholin., anti-hist., psychotrop., digoxin
  • Toxins/withdrawal: EtOH, sedative, opiate, CO
  • Psychiatric: catatonia, serotonin synd., NMS