What is Miller Fisher syndrome?
Peripheral/cranial nerve disorder that results in demyelination - 'locked in like syndrome'
What are the different states of consciousness?
Alertness - normal state of awareness
Somnolence - drowsy, pre-sleep state with decreased attention
Sopor (obtundation) - transition between drowsy and stupor, the patient is confused and cannot easily be alerted
Stupor - can be semi-roused only by vigorous stimulation
Coma - cannot be roused, reflexes diminished or absent
What are the features of locked in syndrome?
Aware and awake, able to breathe
Cannot move or speak
Damage to the ventral pons
Communicate by blinking or eye movement
Feel pain and touch, positions of limbs
What is brain stem death?
Unable to breathe and unconscious. Destroyed reticular formation (brain stem). No electrical activity. No clinical evidence of brain function
• Preconditions: diagnosis compatible with brain stem death; presence of irreversible structural brain damage; apnoeic
• Exclusions: drug effects; hypothermia; metabolic abnormalities; endocrine abnormalities; intoxification
What clinical tests are used to establish brainstem death?
Absent brain stem reflexes (pupils, corneal, no motor response in the cranial nerves, gag, cough, vestibulo-ocular) persistent apnoea
Two practitioners (one consultant) on two occasions
What is a persistant vegetative state?
Unconscious and unaware.
Unresponsive to external stimuli except possibly pain.
Eyes open, can track, dysconjugate.
Sleep wake cycle or chronic wakefulness.
May smile, cry, moan, scream without stimulus
Diagnosis if not recovered from a vegetative state after 30 days. 50% chance of recovery of consciousness in 6 months. Of those who do most are severely disabled.
Old terminology - now refer to 'prolonged disorders of consciousness'
What is a minimally conscious state?
Severely altered unconsciousness with limited self or environmental awareness which may be episodic, demonstrable by one or more of:
Following simple commands
purposeful response to stimuli (not reflexive): smiling or crying to linguistic or visual cues from emotional stimuli
gestures or vocalisations inc yes or no and regardless of accuracy in response to questions
reaching for objects with clear relation of location and direction of reach; handing objects accommodating size and shape
eye movement or fixation in response to moving or salient stimuli
What is a continuing vs a permanent vegetative state?
Continuing - more than 4 weeks
Permanent - more than 6 months
What is the cause of a vegetative state?
A lesion in the cortex - brain stem still functioning.
For how many years must a patient be in an MCS before it is considered permanent?