Page created on June 3, 2021. Last updated on April 1, 2022 at 10:01
Loss of consciousness can only occur if there is injury to the brainstem, injury to both hemispheres, or a metabolic disorder which affects the entire brain. Hungarian literature classifies unconsciousness as either hypnoid or non-hypnoid.
Hypnoid types of decreased consciousness
- Somnolence – patient responds to voice
- Sopor – patient responds to pain
- Coma – patient is completely unresponsive
These can be caused by:
- High intracranial pressure -> Brain herniation
- Brainstem lesion
- Metabolic cause
Non-hypnoid types of decreased consciousness
- Tenebrosity – decreased awareness after seizure
- Delirium – acute disorientation with agitation, restlessness, etc.
- Due to alcohol, drugs, meningitis, dehydration, infection, etc.
- Decortication – flexion of upper extremities + extension of lower extremities
- Due to diffuse brain hypoxia, like cardiac arrest, with subcortical areas intact
- Akinetic mutism – patient is awake but completely unresponsive, no voluntary activity, no communication, no speech
- Due to frontal lobe lesion
- Locked-in syndrome – patient is awake and aware, but the entire body except the eyelids are paralysed
- Due to brainstem lesion