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Vegetative State Alzheimer Disease |
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(1994) This consensus statement of the Multi-Society Task Force summarizes current knowledge of the medical aspects of the persistent vegetative state in adults and children. The vegetative state is a clinical condition of complete unawareness of the self and the environment, accompanied by sleep-wake cycles, with either complete or partial preservation of hypothalamic and brain-stem autonomic functions. In addition, patients in a vegetative state show no evidence of sustained, reproducible, purposeful, or voluntary behavioral responses to visual, auditory, tactile, or noxious stimuli; show no evidence of language comprehension or expression; have bowel and bladder incontinence; and have variably preserved cranial-nerve and spinal reflexes. We define persistent vegetative state as a vegetative state present one month after acute traumatic or nontraumatic brain injury or lasting for at least one month in patients with degenerative or metabolic disorders or developmental malformations. The clinical course and outcome of a persistent vegetative state depend on its cause. Three categories of disorder can cause such a state: acute traumatic and non-traumatic brain injuries; degenerative and metabolic brain disorders, and severe congenital malformations of the nervous system. Recovery of consciousness from a posttraumatic persistent vegetative state is unlikely after 12 months in adults and children. Recovery from a nontraumatic persistent vegetative state after three months is exceedingly rare in both adults and children. Patients with degenerative or metabolic disorders or congenital malformations who remain in a persistent vegetative state for several months are unlikely to recover consciousness. The life span of adults and children in such a state is substantially reduced. For most such patients, life expectancy ranges from 2 to 5 years; survival beyond 10 years is unusual.
(1994). "Medical aspects of the persistent vegetative state (2). The Multi-Society Task Force on PVS." N Engl J Med 330(22): 1572-9.
Andres, J. and A. Macheta (1998). "[Persistent vegetative state: medical, moral, legal and economic aspects]." Folia Med Cracov 39(3-4): 73-7. The classical definition of persistent vegetative state describes patient who is wakeful but not awake, and indicates intact function of the brain stem and no function of brain cortex. The presence and the degree of awareness is most difficult to assess and causes moral and legal controversies concerning the management of persistent vegetative state. The absence of the perceptual awareness may be the most important clinical characterization for diagnosis. Differential diagnosis includes coma, brain death, locked-in syndrome and minimally responsive state. The pressure of economical factors (managed care) on medical care makes this problem even more complicated.
Andrews, K., L. Murphy, et al. (1996). "Misdiagnosis of the vegetative state: retrospective study in a rehabilitation unit." Bmj 313(7048): 13-6. OBJECTIVE--To identify the number of patients who were misdiagnosed as being in the vegetative state and their characteristics. DESIGN--Retrospective study of the clinical records of the medical, occupational therapy, and clinical psychology departments. SETTING--20 bed unit specialising in the rehabilitation of patients with profound brain damage, including the vegetative state. SUBJECTS--40 patients admitted between 1992 and 1995 with a referral diagnosis of vegetative state. OUTCOME MEASURES--Patients who showed an ability to communicate consistently using eye pointing or a touch sensitive single switch buzzer. RESULTS--Of the 40 patients referred as being in the vegetative state, 17 (43%) were considered as having been misdiagnosed; seven of these had been presumed to be vegetative for longer than one year, including three for over four years. Most of the misdiagnosed patients were blind or severely visually impaired. All patients remained severely physically disabled, but nearly all were able to communicate their preference in quality of life issues-some to a high level. CONCLUSIONS--The vegetative state needs considerable skill to diagnose, requiring assessment over a period of time; diagnosis cannot be made, even by the most experienced clinician, from a bedside assessment. Accurate diagnosis is possible but requires the skills of a multidisciplinary team experienced in the management of people with complex disabilities. Recognition of awareness is essential if an optimal quality of life is to be achieved and to avoid inappropriate approaches to the courts for a declaration for withdrawal of tube feeding.
Ashwal, S. and R. Cranford (1995). "Medical aspects of the persistent vegetative state--a correction. The Multi-Society Task Force on PVS." N Engl J Med 333(2): 130.
Boly, M., M. E. Faymonville, et al. (2005). "Cerebral processing of auditory and noxious stimuli in severely brain injured patients: differences between VS and MCS." Neuropsychol Rehabil 15(3-4): 283-9. We review cerebral processing of auditory and noxious stimuli in minimally conscious state (MCS) and vegetative state (VS) patients. In contrast with limited brain activation found in VS patients, MCS patients show activation similar to controls in response to auditory, emotional and noxious stimuli. Despite an apparent clinical similarity between MCS and VS patients, functional imaging data show striking differences in cortical segregation and integration between these two conditions. However, in the absence of a generally accepted neural correlate of consciousness as measured by functional neuroimaging, clinical assessment remains the gold standard for the evaluation and management of severely brain damaged patients.
Boly, M., M. E. Faymonville, et al. (2004). "Auditory processing in severely brain injured patients: differences between the minimally conscious state and the persistent vegetative state." Arch Neurol 61(2): 233-8. BACKGROUND: The minimally conscious state (MCS) is a recently defined clinical condition; it differs from the persistent vegetative state (PVS) by the presence of inconsistent, but clearly discernible, behavioral evidence of consciousness. OBJECTIVE: To study auditory processing among patients who are in an MCS, patients who are in a PVS, and healthy control subjects. METHODS: By means of (15)O-radiolabeled water-positron emission tomography, we measured changes in regional cerebral blood flow induced by auditory click stimuli in 5 patients in an MCS, 15 patients in a PVS, and 18 healthy controls. RESULTS: In both patients in an MCS and the healthy controls, auditory stimulation activated bilateral superior temporal gyri (Brodmann areas 41, 42, and 22). In patients in a PVS, the activation was restricted to Brodmann areas 41 and 42 bilaterally. We also showed that, compared with patients in a PVS, patients in an MCS demonstrated a stronger functional connectivity between the secondary auditory cortex and temporal and prefrontal association cortices. CONCLUSIONS: Although assumptions about the level of consciousness in severely brain injured patients are difficult to make, our findings suggest that the cerebral activity observed in patients in an MCS is more likely to lead to higher-order integrative processes, thought to be necessary for the gain of conscious auditory perception.
Childs, N. L. and W. N. Mercer (1996). "Misdiagnosing the persistent vegetative state. Misdiagnosis certainly occurs." Bmj 313(7062): 944.
Owen, A. M., M. R. Coleman, et al. (2006). "Detecting awareness in the vegetative state." Science 313(5792): 1402. We used functional magnetic resonance imaging to demonstrate preserved conscious awareness in a patient fulfilling the criteria for a diagnosis of vegetative state. When asked to imagine playing tennis or moving around her home, the patient activated predicted cortical areas in a manner indistinguishable from that of healthy volunteers.
Voss, H. U., A. M. Uluc, et al. (2006). "Possible axonal regrowth in late recovery from the minimally conscious state." J Clin Invest 116(7): 2005-11. We used diffusion tensor imaging (DTI) to study 2 patients with traumatic brain injury. The first patient recovered reliable expressive language after 19 years in a minimally conscious state (MCS); the second had remained in MCS for 6 years. Comparison of white matter integrity in the patients and 20 normal subjects using histograms of apparent diffusion constants and diffusion anisotropy identified widespread altered diffusivity and decreased anisotropy in the damaged white matter. These findings remained unchanged over an 18-month interval between 2 studies in the first patient. In addition, in this patient, we identified large, bilateral regions of posterior white matter with significantly increased anisotropy that reduced over 18 months. In contrast, notable increases in anisotropy within the midline cerebellar white matter in the second study correlated with marked clinical improvements in motor functions. This finding was further correlated with an increase in resting metabolism measured by PET in this subregion. Aberrant white matter structures were evident in the second patient's DTI images but were not clinically correlated. We propose that axonal regrowth may underlie these findings and provide a biological mechanism for late recovery. Our results are discussed in the context of recent experimental studies that support this inference
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| [Glial Cell Regenerative Factor (GCRF)] [Alzheimer Disease] [Neurogenic Program] [References] [RG-100j] |
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Nutritional Medicine Research |