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Clinical Stages of Alzheimer's Disease
Stage 7: Severe Alzheimer's disease
At this stage, AD patients require continuous assistance with basic activities of daily life for survival. Six consecutive functional substages can be identified over the course of this final seventh stage. Early in this stage, speech has become so circumscribed, as to be limited to approximately a half dozen intelligible words or fewer in the course of an intensive contact and attempt at an interview with numerous queries (stage 7a). As this stage progresses, speech becomes even more limited to, at most, a single intelligible word (stage 7b). Once speech is lost, the ability to ambulate independently (without assistance), is invariably lost (stage 7e, Figure 11). However, ambulatory ability is readily compromised at the end of the sixth stage and in the early portion of the seventh stage by concomitant physical disability, poor care, medication side-effects or other factors. Conversely, superb care provided in the early seventh stage, and particularly in stage 7b, can postpone the onset of loss of ambulation, potentially for many years. However, under ordinary circumstances, stage 7a has a mean duration of approximately 1 year, and stage 7b has a mean duration of approximately 1.5 years.
Figure 11 Stage 7: Severe Alzheimer's disease.
Early in the course of this final stage of AD speech ability is limited to only a few words. Later, all intelligible speech is essentially lost, with speech limited to at most, a single intelligible word. Subsequently, ambulatory ability is lost and the patient requires assistance in walking. Each substage of this final seventh stage lasts an average of 1-1.5 years.
In patients who remain alive, stage 7c lasts approximately 1 year, after which patients lose the ability not only to ambulate independently, but also to sit up independently (stage 7d), At this point in the evolution of AD, patients will fall over when seated unless there are arm rests to hold the patient up in the chair (Figure 12). This 7dsubstage lasts approximately 1 year. Patients who survive subsequently lose the ability to smile (stage 7e). At this substage only grimacing facial movements are observed in place of smiles, This 7e substage lasts a mean of approximately 1.5 years. It is followed in survivors, by a final 7f substage, in which AD patients additionally lose the ability to hold up their head independently.
Figure 12 Stage 7d: Severe Alzheimer's disease.
Without armrests on the chair, the patients would fall over.
In the latter portion of the final stage of AD, patients become immobile co the extent that they require support to sit up without falling. With the advance of this stage, patients lose the ability to smile and, ultimately, to hold up their head without assistance, unless their neck becomes contracted and immobile. Patients can survive in this final 7f substage indefinitely; however, most patients succumb during the course of stage 7.
With appropriate care and life support, patients can survive in this final substage of AD for a period of years.
With the advent of the seventh stage of AD, certain physical and neurological changes become increasingly evident. One of these changes is physical rigidity. Evident rigidity upon examination of the passive range of motion of major joints, such as the elbow, is present in the great majority of patients, throughout the course of the seventh stage (Figure 13). In many patients, this rigidity appears to be a precursor to the appearance of overt physical deformities in the form of contractures. Contractures are irreversible deformities which prevent the passive or active range of motion of joints (Figure 14). In the early seventh stage (7a and 7b), approximately 40% of AD patients manifest these deformities. Later in the seventh stage, in immobile patients (from stage 7d to 7f), nearly all AD patients manifest contractures in multiple extremities and joints.
Figure 13 In the final stages of AD patients manifest increasing rigidity.
Rigidity is evident to the examiner in the stage 7 patient upon passive range of motion of major joints such as the elbow.
Figure 14 Contractures of the elbow, wrists and fingers.
Development of joint deformities known as contractures, is an increasing problem in the stage 7 Alzheimer's disease. A contracture is a joint deformity which makes full range of movement of a joint impossible without producing severe pain. Approximately 40% of patients in stage 7a and 7b manifest these deformities to the extent that they cannot move a major joint more than half way. In the immobile Alzheimer's patient (stages 7d to 7f). approximately 95% of patients manifest these deformities which are usually present in many joints.
Neurological reflex changes also become evident in the stage 7 AD patient. Particularly notable is the emergence of so-called 'infantile', 'primitive' or 'developmental' reflexes which are present in the infant but which disappear in the toddler. These reflexes, including the grasp reflex, sucking reflex (Figure 15), and the Babinski plantar extensor reflex (Figure 16), generally begin to re-emerge in the latter part of the sixth stage and are usually present in the stage 7 AD patient. Because of the much greater physical size and strength of the AD patient in comparison with an infant, these reflexes can be very strong and can impact both positively and negatively on the care provided to the AD patient". AD patients commonly die during the course of the seventh stage. The mean point of demise is when patients lose the ability to ambulate and to sit up independently (stages 7c and 7d).
Figure 15 Sucking reflex.
'Primitive' reflexes, also known as 'infantile' reflexes or 'developmental' reflexes, such as the sucking reflex, are evident in the stage 7 Alzheimer's patient.
Figure 16 Babinski or plantar extensor reflex.
Another infantile reflex seen in the stage 7 Alzheimer's patient is the Babinski reflex. This abnormal response to stimulation of the sole of the foot is marked by dorsiflexion of the great toe and fanning of the other digits of the foot.
The most frequent proximate cause of death is pneumonia. Aspiration is one common cause of terminal pneumonia. Another common cause of demise in AD is infected decubital ulcerations. AD patients in the seventh stage appear to be more vulnerable to all of the common causes of mortality in the elderly including stroke, heart disease and cancer. Some patients in this final stage appear to succumb to no identifiable condition other than AD.
From:
The Encyclopedia of Visual Medicine Series
An Atlas of Alzheimer's Disease,
Parthenon, Pearl River (NY),
By Barry Reisberg, M.D.
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