Minimally Conscious State

A disorder of severely altered consciousness in which minimal but definite behavioral evidence of self- or environmental awareness is demonstrated

Distinct from locked-in syndrome and persistent vegetative state

Often follows major head trauma

May be temporary or permanent

Little information is available about its natural history or long-term outlook, which reflect the underlying cause

The likelihood of functional recovery diminishes with time; after 12 months, patients are likely to remain severely disabled and without a reliable means of communication

Inconsistent evidence of consciousness

There may occur some degree of functional recovery of behaviors suggesting self- or environmental awareness, such as

• Basic verbalization or context-appropriate gestures

• Emotional responses (eg, smiling) to emotional but not neutral stimuli

• Purposive responses to environmental stimuli (eg, a finger movement or eye blink apparently to command)

Diagnosis usually made on clinical grounds

• Functional imaging studies show that overall cerebral metabolism is less than in individuals with conscious awareness (20–40% of normal) but slightly higher, though comparable to, those in a persistent vegetative state

• Functional MRI studies show some auditory network cortical activation in response to familiar voices

Amantadine (100–200 mg orally daily) may hasten recovery when given to patients in a minimally conscious or vegetative state 4–16 weeks after a traumatic brain injury

Otherwise, there is no evidence for any other measures that can alter the course of the recovery

Supportive care initially, which may include temporary endotracheal intubation and mechanical ventilation for airway protection, as well as liquid artificial nutrition by nasogastric or percutaneous gastrostomy tube

Palliative care and/or ethics committee consultation to assist families and clinicians in medical decision-making