You left out the most important part: http://pmj.bmjjournals.com/cgi/content/full/75/884/321
Difficulty in diagnosis The International Working Party on Vegetative State13 recognised that deciding the cognitive awareness of this type of patient, especially when at a very low level, was an educated guess since there are, as yet, no tests which can confirm whether the patient has any `inner awareness'. They pointed out that the assessments in general use are based on a series of behavioural patterns. The clinician is, therefore, dependent on overt responses which depend on: the physical ability of the patient to respond the desire or willingness (if the patient is aware) of the patient to respond the abilities of the observer to make rapport with the patient the ability to observe accurately the time available for observation and assessment the lack of available and reliable assessment tools. It is essential to understand that the diagnosis is based on the presentation of clinical features since it is basically a behavioural model. There are three prime features of the vegetative state. The first is that the patient has sleep-awake patterns; this differentiates the condition from coma. This is a feature which can be easily detected by the lay person. There is the theoretical possibility that a patient with bilateral third nerve palsy could be aware but have no eye opening. I have only come across one case (in America) where this has been shown to have happened. The second feature is that all responses can be identified as reflex patterns. This requires considerable neurological knowledge of reflex patterns. The third element, the other side of the coin to reflex patterns, is that the patient makes no meaningful responses and has no awareness. This is much more difficult since the only way anyone can demonstrate their awareness is through a motor function, ie, speech, facial expression, or physical gesture. In the presence of severe spasticity, muscle inactivity and dysphasia it is extremely difficult for even an aware person to demonstrate their awareness. This difficulty has been seen in several studies. Childs et al20 report that 37% of patients admitted more than one month post injury with a diagnosis of coma or persistent vegetative state had some level of awareness. In a group of longer term patients in a nursing home, Tresch et al21 found that 18% of those diagnosed as being in the persistent vegetative state were aware of themselves or their environment. The study by Andrews et al15 highlights some of the major problems in making a diagnosis of the vegetative state. They reviewed the records of 40 consecutive patients admitted to their specialist profound brain injury unit at least 6 months following their brain injury (a period after which spontaneous recovery is generally regards as limited) with a referral diagnosis of vegetative state. They found that whilst 25% remained vegetative, 33% emerged during the rehabilitation programme, and 43% had been misdiagnosed (41% of these for more than a year including three for more than 5 years). The level of cognitive functioning present in this misdiagnosed group at the time of discharge was considerable: 60% were orientated in time, place and person, 75% were able to recall a name after 15 minutes delay, 69% were able to carry out simple mental arithmetic, 75% were able to generate words to communicate their needs and 86% were able to make choices about their daily social activities. The predominant features which seem to have lead to misdiagnosis were that all the patients were profoundly physically disabled and 60% were blind or severely visually impaired. Since clinicians use visual tracking as an important sign that the patient is emerging from the vegetative state, and this sign was usually absent because of the damage to the visual tracts, the patients were mistakenly assumed to be vegetative. There are several prerequisites for the accurate assessment of the person thought to be in the vegetative state: The patient should be healthy. Even simple conditions such as constipation, chronic urinary tract infection (usually associated with long term catheterisation) or chest infections can prevent optimal responses from being obtained. The patient should be in a good nutritional state. Until recently as many as 80% patients admitted to our specialist unit were suffering from undernutrition. The earlier use of gastrostomy feeding has altered this pattern but still about 30% of patients admitted have a low Body Mass Index, emphasising the difficulty in managing people with complex medical and physical disabilities. As many sedating drugs as possible should be withdrawn, or at least decreased to the lowest effective dose; this includes antispasticity and anti-epileptic drugs. In the case of anti-epileptic drugs which are still required to control fitting, drugs with the least sedative effect should be used. Complications and consequences of neurological imbalance should be prevented; this includes high muscle tone and contractures by the provision of special seating, good bed and sitting posture to control abnormal muscle tone. These complications in the long term increase the amount of nursing care required which, since the patient may live for many years, increases the cost of care considerably. Controlled posture is important. Most doctors have been trained to examine patients on the bed. Experience suggests that patients are more likely to be alert when sitting up (presumably due to greater stimulation of the reticular activating system). A well supporting seating system is essential to reduce sufficient muscle tone to allow movement of limbs which can be used for communication purposes, eg, to press a touch-sensitive switch. Providing a controlled environment of sensory regulation to avoid sensory overload of the severely damaged brain. Since it is likely that profoundly brain-damaged patients have a problems with selective attention, sensory input should be simple and interspersed with periods of rest. It is, therefore, logical to assess for cognitive responses after a period of rest rather than after a period of activity, such as being washed and dressed, or after a period of physiotherapy. This requires staff and family to understand the importance of avoiding overstimulation prior to the assessment. Assessments should be short (to avoid tiring the patient), repeated (to identify windows of opportunity) and carried out over a period of time (to accommodate the learning process of both the patient and the assessor). A short, one-off, assessment of the patient who is lying in bed is likely to result in a missed diagnosis, even by very experience clinicians. The ability to generate a behavioural response fluctuates from day to day and hour to hour, and even minute to minute, depending on fatigue factors, general health of the patient and the underlying neurological condition. Observation needs to take into account delayed responses. Assimilation of even basic information is often slow and therefore response time may be delayed. Because of this, information provided at any one time should be simple, consistent, repeated after a period of rest and allow for a delayed response. Communication requires skilled techniques and a sensitivity for the method by which the patient wants to communicate. Families and other carers have a very important role in identifying the best responses and the optimal conditions for assessment. Whilst there are some relatives who interpret reflex responses as being meaningful, there is no doubt that members of the family are often more sensitive to early changes than even experienced clinical staff. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~| All-in-one: antivirus, antispam, firewall for your PC and PDA. Buy Trend Micro PC-cillin Internet Security http://www.houseoffusion.com/banners/view.cfm?bannerid=60 Message: http://www.houseoffusion.com/lists.cfm/link=i:5:144673 Archives: http://www.houseoffusion.com/cf_lists/threads.cfm/5 Subscription: http://www.houseoffusion.com/lists.cfm/link=s:5 Unsubscribe: http://www.houseoffusion.com/cf_lists/unsubscribe.cfm?user=11502.10531.5 Donations & Support: http://www.houseoffusion.com/tiny.cfm/54
