Reviewed and revised 20 September 2016
- Pseudocoma is the term used for a patient feigning a comatose state, however it is sometimes also used for conditions like locked-in syndrome where patients may involuntarily appear unconscious but are actually self aware
- This document focuses on how to distinguish feigned coma from true coma
The pattern of clinical findings are not consistent with a specific neurological syndrome or anatomical lesion.
- pupils are equal and reactive to light.
- passive eyelid opening results in pupillary constriction, whereas if the patient is sleeping or comatose (with intact pupillary reflexes) the pupils dilate on passive eyelid opening.
- Eye movements and oculovestibular reflexes:
- fluttering of the eyelids when the eyelashes are gently stroked
- the patient may resist passive eye opening. Occasionally patients with metabolic or structural lesions may resist eye opening.
- any spontaneous eye movements are saccadic (rapid and jerking) rather than slowly roving
- the patient actually makes eye contact with the examiner when the eyelids are opened; or the eyes always look to the side away from the examiner, or the eyes always look towards the ground
- the awake patient’s eyes move concomitantly with head rotation when assessing the oculocephalic reflex. It is nearly impossible for an awake patient to mimic the brainstem oculocephalic responses of a truly comatose patient.
- on cold caloric testing the patient may wake up or exhibit preservation of the fast component of nystagmus.
- active resistance or varying resistance to passive motor tone testing, or cog-wheeling resistance with sudden “giving-away” phenomena
- no abnormal reflex posturing in response to painful stimuli
- the patient may occasionally make voluntary movements or change body position in bed
- the patient will show avoidance of ‘self injury’ — do not allow the patient to be injured!
- Eyelid apraxia (or lid opening apraxia) is the inability to voluntarily open eyes despite intact frontalis muscle contraction and normal oculomotor function
- Is an unusual coma mimic
- Caused by injuries of:
- the non-dominant hemisphere (e.g. R MCA stroke)
- medial frontal lobe
- bilateral thalami (e.g. bilateral thalamic stroke)
- brainstem (e.g. progressive supranuclear palsy)
- Suspect this condition if the patient tries to raise their eyelids by contracting forehead muscles when asked to open eyes
References and Links
- Posner JB, Saper CB, Schiff N, Plum F. Plum and Posner’s Diagnosis of Stupor and Coma 4e Oxford university Press, 2009.
Chris is an Intensivist and ECMO specialist at the Alfred ICU in Melbourne. He is also a Clinical Adjunct Associate Professor at Monash University. He is a co-founder of the Australia and New Zealand Clinician Educator Network (ANZCEN) and is the Lead for the ANZCEN Clinician Educator Incubator programme. He is on the Board of Directors for the Intensive Care Foundation and is a First Part Examiner for the College of Intensive Care Medicine. He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives.
After finishing his medical degree at the University of Auckland, he continued post-graduate training in New Zealand as well as Australia’s Northern Territory, Perth and Melbourne. He has completed fellowship training in both intensive care medicine and emergency medicine, as well as post-graduate training in biochemistry, clinical toxicology, clinical epidemiology, and health professional education.
He is actively involved in in using translational simulation to improve patient care and the design of processes and systems at Alfred Health. He coordinates the Alfred ICU’s education and simulation programmes and runs the unit’s education website, INTENSIVE. He created the ‘Critically Ill Airway’ course and teaches on numerous courses around the world. He is one of the founders of the FOAM movement (Free Open-Access Medical education) and is co-creator of litfl.com, the RAGE podcast, the Resuscitology course, and the SMACC conference.
His one great achievement is being the father of three amazing children.
On Twitter, he is @precordialthump.