Disease relevance of Persistent Vegetative State

• Sixteen percent of the patients achieved an independent existence within a month; severe disability or the vegetative state developed in 25% of patients comatose for six hours and in 79% of those still in coma after a week [1].
• To elucidate the clinical course of the vegetative state after severe closed-head injury, the Traumatic Coma Data Bank was analyzed for outcome at the time of discharge from the hospital and after follow-up intervals ranging up to 3 years after injury [2].
• Diffuse axonal injury (DAI) in the central nervous system is a common cause of post-traumatic coma and may result in varying degrees of disability up to and including the vegetative state [3].
• Frontoparietal hypometabolism is also implicated in unconscious states, including deep sleep, coma, vegetative states, epileptic loss of consciousness, and general anesthesia [4].
• The presented definition of hopeless injury does not require brain death, coma, or persistent vegetative state [5].

Psychiatry related information on Persistent Vegetative State

• A persistent vegetative state (severe dementia) developed in a 30-year-old man following hypoglycemic coma [6].
• One patient died, 1 patient entered a persistent vegetative state, and the others recovered fully from Wernicke encephalopathy within 2 weeks to 1 year after thiamine administration [7].
• To clarify the pathophysiological differences of the cerebrovascular reserve capacity in relation to cerebral cognitive impairments between vascular dementia (VaD) and persistent vegetative state (PVS), we evaluated acetazolamide (ACZ) vasoreactivity testing by transcranial harmonic perfusion imaging (HPI) and Doppler sonography (TCD) [8].

High impact information on Persistent Vegetative State

• In a landmark decision, the Supreme Judicial Court of Massachusetts ruled that a feeding tube could be removed from a patient in a persistent vegetative state if this was consistent with his previously expressed wishes [9].
• Seven patients recovered from coma after the serum sodium level was increased to 131 mmol per liter, but coma recurred two to six days later and ended in either death or a persistent vegetative state [10].
• Positron emission tomography with the benzodiazepine receptor ligand carbon-11-labelled flumazenil Identified the extent of neuronal damage in acute vegetative state and predicted the possibility of recovery of consciousness and function [11].
• Cortical processing in persistent vegetative state. Wolfson Brain Imaging Centre Team [12].
• 17 (57%) of 30 patients with APOE epsilon4 had an unfavourable outcome (dead, vegetative state, or severe disability) compared with 16 (27%) of the 59 patients without APOE epsilon4 (p=0.006) [13].

Chemical compound and disease context of Persistent Vegetative State

• Of prognostic importance, patients with increased lactate were more likely to be severely disabled (39% vs 10%), survive in a persistent vegetative state (13% vs 2%), or have died (39% vs 7%) [14].
• The peak value of EAAs in the poor-outcome group (including severe disability, vegetative state, and death) was significantly higher than in the good-outcome group (good recovery and moderate disability; Glu, P <0.001; Asp, P <0.01); GOS was closely correlated to the EAA values (Glu, rs = 0.5737, P <0.001; Asp, rs = 0.5470, P <0.001) [15].
• It was found that the coupling between neuronal electrical activity and regional glucose metabolism was preserved in all the minimally conscious patients but was absent in all the vegetative state patients [16].
• The outcome was significantly better in the patients with a good or partial ICP response to pentobarbital, with 21% of these patients having a good recovery or moderate disability at 3 months after injury, compared with 100% persistent vegetative state or death in the nonresponders [17].
• Twenty-four-hour profiles of growth hormone, prolactin and cortisol in the chronic vegetative state [18].

Biological context of Persistent Vegetative State

• Eye movements induced by head rotation were studied in 6 patients in acute coma, 4 patients in a persistent vegetative state, and 6 healthy, alert control subjects [19].
• Evoked potentials for the prediction of vegetative state in the acute stage of coma [20].
• There is now evidence that coma and vegetative states are sometimes reversible with a combination of treatments, among them neuropharmacology [21].
• A clinico-physiological study of visually evoked potential (VEP) and somatosensory evoked potential (SEP) in so-called vegetative state and delta coma [22].
• An nonlinear indicator of Functional Isolation, named approximated entropy (ApEn), assessed within cerebral cortex in patients with a vegetative state it's recently found as a promising tool for the prediction of recovery. The theoretical framework arise from a simple assumption: since we still have not found the [neural correlates of consciousness] it may be beneficial to use an "indirect extimator" of the mean functional isolation degree within the cerebral cortex of patients. By this way it's possible to test not only a well defined circuitery in the brain cortex but also the "ghost networks". This is because a diffuse functional isolation shot out the arising of whichever possible wide functional neuronal's ensamble (with both a well and not defined "anatomy") [23] [24]

Anatomical context of Persistent Vegetative State

• It also demonstrates that large traumatic lesions of the corpus callosum may occur without prolonged posttraumatic coma, vegetative state, or death [25].

Gene context of Persistent Vegetative State

• The classic form of ALD usually has onset in childhood (childhood cerebral ALD), with rapid neurologic deterioration leading to a vegetative state [26].
• However, IFN-alpha caused severe neurotoxicity in form of an only partly reversible progressive vegetative state in the majority of patients [27].
• The infantile subtype of NCL (INCL) is characterized by early visual loss and mental deterioration, and leads to a vegetative state of the patients by 3 years of age [28].
• Persistent vegetative state in Alzheimer disease. Does it exist [29]?
• When AD subjects were divided into those still ambulatory prior to death (CDR 3/4) and those in a prolonged 'vegetative' state prior to death (CDR 5), differences among groups became apparent at specific levels of the LC [30].

Analytical, diagnostic and therapeutic context of Persistent Vegetative State

• The Victorian Supreme Court has decided that artificial nutrition and hydration provided through a percutaneous gastrostomy tube to a woman in a persistent vegetative state may be withdrawn [31].
• A Coma Exit Chart can be developed using the parameters of the Glasgow Coma Scale to measure the exiting of the patient from prolonged coma or the vegetative state [32].

References