The progression from unconsciousness and coma to recovered wakefulness – either direct or with a transition through a condition such as the vegetative state – is often characterized by a very complex clinical picture, which is determined by pathophysiological mechanisms that are only known in part. The treatment of patients in this phase – in relation to total or partial recovery of higher brain functions/mental functions – implies detailed procedures, while nursing practices and the many measures required to avoid secondary complications follow precise rules. The recovery of higher brain functions and mental activity requires individualized treatment and relies on an empirical approach, which is usually also based on the creativity, collaboration, and drive of the therapists and family members concerned. Such care cannot replace rehabilitative procedures conceived as part of a scientific plan of treatment. When there are deficits for which detailed identification of the physiopathological basis is lacking, a thoroughly scientifically based therapeutic model must be followed. Experimentation should never be justified in patients who are not in a position to choose treatment or discuss the risks with the attending physician. Although often underestimated, this aspect may generate moral dilemmas for those who are in charge of patients in vegetative state, as these patients present with the most serious of all deficits: the loss of identity. It is also for this reason that, after many years of work with such patients, we have felt the need to carry out close scrutiny and critical evaluation of our experience in order to revise the available clinical outline of the vegetative state and to try characterize the world in which patients in this condition live. This rationale has allowed us to elaborate a new approach to the diagnosis, prognosis, and treatment of patients in the vegetative state.
The driving force behind the preparation of this manual has been not only our immense curiosity and interest in this pathology and its mysterious features, which involve the most highly evolved function of the human being – awareness – but also the love we have felt for those individuals who, through their illness, have contributed to the growth in the quality of our own awareness.
History of the Concept of Vegetative State
The Oxford American Dictionary defines “vegetative state” as a condition of living “a merely physical life, devoid of intellectual activity or social intercourse” that is characteristic of “an organic body capable of growth and development but devoid of sensation and thought” . The term “vegetative” is used in the scientific terminology of several languages to signify an “autonomous being.”
More than a century ago, in 1899, Rosemblath described the first case of a long-term “chronic” coma in which the patient survived for 8 months on artificial nutrition . The very specific clinical picture of a patient lying passively, akinetic, unresponsive, and with eyes open was described by Kretchmer in 1940 as an “apallic” syndrome, with the term “apallic” being meant to describe the loss of complex functions of the cerebral cortex (pallium) . To the author, this functional decortication signified a “mesencephalic” existence. According to Kretchmer, the loss of cortical function, due either to cortical (and white matter) or brain-stem lesions, presents a typical picture of a condition in which there is no contact with the outside world, lack of reaction and recognition, and an attentive look. Kretchmer described this syndrome as an expression of panagnosis and panapraxis. In 1972, Jennett and Plum described this clinical picture in terms of a global disturbance in cognitive function .
Following the efforts of several authors, this clinical condition was described in progressively greater detail, and various definitions of it were suggested, including the term “vegetative state” originally proposed by Jennett in 1972 and accepted by the London workshop . Publications by the American Task Force on the vegetative state in 1994 and by the London conference marked a milestone in the study of this serious cerebral pathology, by defining the vegetative state in terms that still apply today. In spite of its negative connotations, the term “vegetative state” does in fact fulfill two requirements in defining the condition: it is universally broad and etymologically correct. The heading “vegetative state” now also includes several syndromes that are often confused with other conditions in the relevant literature, due to the lack of a precise definition based on clinical or anatomical-pathological criteria.
Irrespective of whether its origin is post-traumatic or vascular, a vegetative state may develop after 3–4 weeks of coma, or can occur as a result of progressive, degenerative, or congenital neurological disease. According to the American Task Force, a vegetative state is characterized by concomitant findings of:
• Absence of awareness of self or environment and inability to interact with others
• Absence of sustained or reproducible behavioral or voluntary responses; absence of responses to auditory, visual, tactile, or noxious stimuli
• No comprehension or verbal expression
• Intermittent wakefulness, occasionally observed in the presence of a sleep-wake cycle
• Sufficiently preserved autonomic functions of the hypothalamus and brain stem, allowing survival with medical and nursing care
• Sphincteral incontinence
• Preserved spinal and cranial nerve reflexes (pupillary, oculocephalic, corneal, oculovestibular, and gag)
According to Sazbon, the condition referred to as “vegetative state” is characterized by two cardinal signs – wakefulness and unawareness. Any condition included within this framework is to be considered as a vegetative state, regardless of origin, etiology, duration, course, or outcome. All authors agree with the American Task Force in accepting that two cardinal features characterize the clinical picture: that the vegetative state is one of three possible progressions of coma (although it represents a special condition), and that it manifests a loss of the contents of consciousness even after the recovery of vigilance – as distinct from coma. “Contents of consciousness” is meant to describe both the ability to relate to the outer world (awareness) and the awareness of self. It is apparent that the contents of consciousness are lacking in the vegetative state, as also are sensory functions, attentiveness, and spatiotemporal orientation – that is, all of the functions that make up a conscious experience of the outer world.
• The vegetative state is an expression of a direct primary brain pathology, and is not an extension of coma. Although existing from the outset of the brain pathology, the vegetative state may be masked by a state of coma, thus hindering a proper diagnosis.
• We believe inappropriate attention has been given to those functions that allow the patient to relate with the inner world, including in addition to imagination, ideas, and will, feelings and memory as well – all functions that allow the continuation of mental life.
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