Vegetative state: causes, symptoms, diagnosis, treatment

The vegetative state is a prolonged non-conditioned state of disorientation and areactivity associated with extensive cerebral hemispheric dysfunction, but the intermediate brain and trunk provide vegetative and motor reflexes, as well as the alternation of the phases of sleep and wakefulness. Usually complex reflexes are preserved, among them eye movements, yawning, involuntary movements in response to pain stimuli, but the awareness of oneself and the environment is lost. The diagnosis is based on the clinical picture and the duration of the condition. The prognosis is unfavorable, the treatment is symptomatic. Termination of treatment should be discussed with family members.

Unlike coma in the vegetative state, it is possible to open the eyes and alternate between sleeping and waking, but there is also no awareness of the environment. In the vegetative state, VARS remains functionally active, but the cerebral cortex is largely damaged. With adequate treatment and care, the activity of the hypothalamus and the brainstem is sufficient for the survival of patients.

Symptoms of the vegetative state

Signs of awareness of oneself and the environment are not manifested, the patient can not come into contact. Stable, targeted reactions to external stimuli, understanding and speech are absent.

Signs of preservation of VARS (opening of the eyes, periods of wakefulness with irregular cycles of sleep-awakening) and intact trunk (for example, pupillary reactions, oculocephalic reflex) are determined. There are complex stem reflexes, including yawning, chewing, swallowing and, occasionally, guttural sounds. Reflexes of awakening and flinching may persist, so loud sounds and bright flashes of light can cause eye opening. Eyes are moistened, the development of tears is preserved. Spontaneous wandering eye movements - usually slow with constant speed and without saccadic twitching - are often misinterpreted as conscious tracking that disorients family members.

Limbs can move, but only within the framework of primitive targeted motor reactions (for example, grasping an object that touches the arm). Pain can provoke the adoption of decorticative and decerebral poses, or only pseudo-directed or non-targeted avoidance reactions. It is characterized by incontinence of urine and feces. Functions of the cranial nerves and spinal reflexes are usually preserved.

The diagnosis is based on a typical clinical picture of symptoms and signs in the context of CNS involvement. Neuroimaging, EEG and somatosensory evoked potentials usually do not add anything to the diagnosis.

Forecast and treatment of vegetative state

Restoration from the vegetative state after 3 months after non-traumatic brain damage and 12 months after the injury is rare. At best, recovery involves a state of moderate - severe functional failure. Occasionally, the improvement comes in a later period, so, after about 5 years, the ability to communicate and comprehend can recover in about 3% of cases, but return to independence in everyday life is even rarer and none of the patients is restored to normal.

Most patients in the vegetative state die within 6 months due to infections of the lungs, urinary tract, multiple organ failure or suddenly die for an unknown reason. For the rest, the life expectancy is 2-5 years, and some live for tens of years.

Treatment is aimed at preventing systemic disorders (for example, pneumonia, urinary tract infections), providing good nutrition, preventing bedsores and physical exercises to prevent the development of contractures in the limbs. Patients may not perceive pain, but respond to it with motor reflex movements. To address care issues, social services, the ethics committee of the hospital, and frequent family members should be involved. Preserving the life of a patient who is in a stable vegetative state for longer than 6 months, especially without a prediction in the sense of making decisions about discontinuing treatment, raises social and ethical problems.

[1], [2]