The influence of acoustic and tactile stimulation on vegetative parameters and EEG in persistent vegetative state

In the present study, we investigated whether different kinds of stimulation in the persistent vegetative state (PVS) lead to specific patterns of physiological reactions. In addition, a possible effect of stimulating drugs was explored by comparing recordings with and without pharmacological stimulation. Eighteen patients in the PVS were submitted to tactile or acoustic stimulation. The latter consisted of white noise and of the voices of close relatives delivered via a digital voice recorder. Additionally, half of the patients were pharmacologically stimulated with amantadine, L-dopa or amphetamine. The effect of stimulation was assessed by recording the electroencephalogram (EEG), electromyogram (EMG), skin conductance response (SCR) and heart rate (HR). Tactile stimulation was associated with statistically significant increases in EEG and EMG parameters, SCR and HR. White noise stimulation led to significant increases in SCR and EMG parameters. The physiological responses to relatives? voices did not differ from baseline activity. Pharmacological stimulation increased the baseline level of activation, but showed no interaction with sensory stimulation. The data presented indicate that the level of arousal in patients in the PVS can be adequately monitored by measuring SCR, HR and EMG parameters.     

Recognizing a mother's voice in the persistent vegetative state.

We studied an 8-year-old boy after a near-drowning left him in a vegetative state (VS) for 4 years before the study. Findings fulfilled all clinical criteria for the diagnosis of VS. The purpose of this study was to investigate whether there was significant differential activation of the brain in response to hearing his mother's voice compared with the voices of unknown women. The data were assessed using quantitative electric tomography (QEEGt), a technique that combines anatomical information of the brain by MRI with EEG patterns to estimate the sources of the EEG within the brain. We found significant differences for EEG frequencies from 14-58 Hz, with a peak at 33.2 Hz (gamma band). The 3D reconstruction showed that these statistical differences were localized in the lateral and posterior regions of the left hemisphere. No significant differences were found between unknown women vs. basal conditions. These results demonstrate recognition of the mother's voice and indicate high-level residual linguistic processing in a patient meeting clinical criteria for VS. These findings launch new ethical and practical implications for the management of VS patients.     

Clinicophysiological study of multimodality evoked potentials and computed tomographic findings in persistent vegetative state

The auditory brainstem response (ABR), short latency somatosensory evoked potential (SSEP) and visual evoked potential (VEP) of patients in the persistent vegetative state (PVS) are reported, and the correlations between the electrophysiological findings and the CT scan findings with the three clinical grades of the PVS (transitional, incomplete and complete vegetative syndromes) are discussed. Twenty two patients in a vegetative state caused by subarachnoid hemorrhage (3), hypertensive intracerebral hemorrhage (5), cerebral infarction (6), head injury (3), cerebral anoxia (4) and brain tumor (1). Each evoked response was evaluated for the presence or absence of abnormalities and assigned a grade ranked I to III. Briefly an evoked response was assigned a grade I, II, III if it satisfied the respective criteria of normal, moderately abnormal and severely abnormal or absent electrical activity. On the other hand CT scan findings in the PVS were evaluated for abnormal low density areas, ventricular dilatation and enlargement of the sulci and cisterns indicative of atrophy of the brain parenchyma. SSEP and VEP were better correlated with the clinical grade than ABR, and upper brainstem atrophy and abnormal low density area in CT scan findings were more valuable as an index to expresses the clinical features than ventricular dilatation. On the basis of these results, it is concluded that studies of ABR, SSEP and VEP associated with CT scan findings in the PVS could be a useful diagnostic aid to evaluate the lesions of these patients.     

Detecting residual cognitive function in persistent vegetative state

Despite converging agreement about the definition of persistent vegetative state, recent reports have raised concerns about the accuracy of diagnosis in some patients, and the extent to which, in a selection of cases, residual cognitive functions may remain undetected. Objective assessment of residual cognitive function can be extremely difficult as motor responses may be minimal, inconsistent, and difficult to document in many patients, or may be undetectable in others because no cognitive output is possible. Here we describe strategies for using H(2)(15)O positron emission tomography activation studies to study covert cognitive processing in patients with a clinical diagnosis of persistent vegetative state. Three cases are described in detail. Of these, two exhibited clear and predicted regional cerebral blood flow responses during well-documented activation paradigms (face recognition and speech perception) which have been shown to produce specific, robust and reproducible activation patterns in normal volunteers. Some months after scanning, both patients made a significant recovery. In a third case, blood flow data were acquired during a speech perception task, although methodological difficulties precluded any systematic interpretation of the results. In spite of the multiple logistic and procedural problems involved, these results have major clinical and scientific implications and provide a strong basis for the systematic study of possible residual cognitive function in patients diagnosed as being in a persistent vegetative state.     

CT appearance of children in a persistent vegetative state

A morphometric CT study was performed on 17 children who were in a persistent vegetative state. Four cases with compromised brain stem function (group 1) showed a significantly smaller lateral pontine ratio (LPR, width of pons/greatest internal diameter between temporal bone) than the remaining 13 cases with preserved brain stem function (group 2) and controls. LPR was considered a useful indicator of brain stem atrophy and to correlate well with brain stem function.     

持续植物状态34例患者的评估

目的探讨准确、可靠、客观的床旁持续植物状态评估方法。方法对34例脑损害后昏迷转为持续植物状态的患者进行脑功能评估。临床指标包括意识状态、7项脑干反射、4项脑神经支配活动、3项脊髓反射、1项脊髓自动反射和2项脊神经支配活动；神经电生理指标包括脑电图（Youg分级评估标准）、脑干听觉诱发电位和短潜伏期体感诱发电位（Cant分级评估标准）。结果缺血缺氧性脑损害（30／34，88．2％）是最常见的脑损害原因。意识状态从早期浅度、中度或深度昏迷转为睁眼昏迷，脑干反射和脑神经支配的活动全部或部分存在，肢体自主运动部分存在或消失，脊髓反射全部或部分存在，脊髓自动反射全部或部分存在，脊髓病理反射部分阳性。脑电图判定Ⅰ级和Ⅵ级的分别为64．5％（20／31）和29．0％（9／31），Ⅲ级和Ⅳ级的共6．5％（2／31）。脑干听觉诱发电位判定Ⅰ级、Ⅱ级和Ⅲ级的分别为34．8％（8／23）、21．7％（5／23）和43．5％（10／23）。短潜伏期体感诱发电位判定Ⅰ级和Ⅲ级的分别为43．5％（10／23）和52．2％（12／23），Ⅱ级的仅4．4％（1／23）。全部34例患者中死亡10例（29．4％），在35～90d内意识清醒者4例（11．8％）。结论临床指标符合持续植物状态患者的脑功能状态存在差异，多项电生理技术的联合可对其做出准确、客观、可靠的评定，并为临床医疗决策提供重要参考意见。     

植物状态患者脑电反应性量化分析

目的探讨脑电反应性量化分析在植物状态患者预后判别中的价值。方法采用目测及计算机量化分析判别痛觉刺激前、后植物状态患者的脑电图反应性,与患者意识恢复进行相关性分析,进而比较两种分析方法的敏感性、特异性及准确性。结果 28例患者中,11例意识恢复,17例未恢复。目测组有反应性11例,其中7例意识恢复;量化分析组有反应性10例,9例意识恢复。两组均与患者意识恢复有相关性,P值均<0.05。脑电图EEG反应性量化分析组对植物状态患者意识恢复判断的敏感性为94.12%、特异性为81.82%、准确性为89.29%、均高于目测观察组(76.47%,63.64%,71.43%)。结论脑电反应性计算机量化分析可准确预测植物状态患者的意识恢复能力,可作为临床评估植物状态患者意识恢复能力的有效方法。     

Prevalence of persistent vegetative state/apallic syndrome in Vienna

The aim of the project was to survey the hospital prevalence of apallic syndrome in a federal state in Austria at an exact point in time. To achieve this, a point prevalence study was carried out on 28 November 2001 in the Vienna region. The central element was a questionnaire, which provided an exact recording of the patients' condition. An additional preliminary task was to check all the discharge diagnoses in the hospitals of the Vienna Hospital Association (Wiener Krankenanstalten Verbund) between 1996 and 2000 according to the ICD-9 diagnoses for apallic syndrome. These data should serve to cross-check the recorded results. All hospitals (n = 48) and nursing facilities (n = 44) in Vienna were included in this investigation. As the aim of the study was to record the prevalence of apallic syndrome in the population of Vienna, four patients of the group with full-stage apallic syndrome (n = 36) were excluded as they were from other federal states. In total, 32 hospital patients who met the clinical criteria for apallic syndrome (full-stage) were recorded. The point prevalence of apallic syndrome was 1.9/100,000 inhabitants. As a result of this study, the exact survey of hospital prevalence of apallic syndrome could be found. As a consequence, the Viennese government has developed a rehabilitation concept for patients with apallic syndrome in Vienna.     

脑外伤后持续性植物状态2例

在临床上,脑外伤后持续性植物状态（persistent vegetativestate,PVS）的苏醒恢复一直是一个难题,近期我们收治了2例PVS,治疗效果良好,现报告如下。 例1,男性,49岁。因车祸伤致意识障碍及双下肢损伤约6h入院。患者伤后持续昏迷,无呕吐,大、小便均失禁。查体:深昏迷,双侧瞳孔等大等圆、直径约4.0mm,光反应消失,双侧巴彬斯基征（+）。全身多处损伤,尤以头部和右侧小腿为重。头颅CT示右额、双颞、胼胝体、左枕和脑干等多部位脑挫裂伤,弥漫性轴索损伤,右额骨骨折。诊断为特重型颅脑损伤,右下肢开放性骨折伴大面积撕脱伤。入院后给予抗休克、止血、降颅压和抗炎等治疗,并行右下肢截肢术。3d后生命体征平稳,开始静脉输注神经营养剂促醒,2月后行高压氧、针灸治疗,同时辅以听觉和理疗刺激。8个月后患者苏醒。出院时神志清楚,问答切题,智力正常。视力无障碍、视野无缺损,双上肢及左下肢活动自如,肌力V级。小便正常,大便仍失禁。     

Five-year follow-up study of patients with persistent vegetative state

One hundred and ten patients with persistent vegetative state, were followed up for a period of five years from 1973 to 1978. Seventy-three per cent of the patients died during the period while about 10% of them recovered partially from the vegetative state. Among the recovered patients, only three became able to communicate, but two of these are not independent for their daily activites. Reactivity and clinical symptoms of 30 survivors were examined, but no great changes occurred during the last two years of the study.     

Epidemiological studies on patients with a persistent vegetative state

Persistent vegetative state after severe brain damage was studied epidemiologically in 110 cases from 1973 to 1976. The causes of brain damage were varied. More than one-third of the cases were due to trauma, and about one-fifth were the result of vascular accidents. Three year observation revealed that 65% of the patients died during this period. Mean survival time for dead patients was 38 months. Reactivity, clinical signs, EEG findings, methods of management, and results of various trials of treatment were investigated in connection with the patient's prognosis.     

Patients in a persistent vegetative state: caregiver attitudes and reactions

OBJECTIVES: This exploratory study investigated the problems encountered by caregivers of long-stay hospital patients in a persistent vegetative state. MATERIAL AND METHODS: Sixteen primary caregivers completed questionnaires designed to assess their personality, psychophysical distress, coping strategies and caregiving-related problems. RESULTS: Males showed a higher level of emotional distress and neuroticism than females. All of the caregivers used situation-oriented coping strategies less over time. had apparently unsatisfactory family relationships, and their emotional distress increased with disease duration. The thoughts of the possible death of the patient were associated with anxiety and depressive symptoms. The caregivers' everyday lives were characterized by limited social relationships, and indoor and outdoor interests. CONCLUSION: Our study underlines the importance of psychosocially assessing PVS patient caregivers, who are often alone in coping with a irreversible situation. It also introduces a questionnaire (FSQ2) that seems to be sufficient to assess the caregiving-related problems.     

The persistent vegetative state in children: report of the Child Neurology Society Ethics Committee.

Increasing concern about children in a persistent vegetative state (PVS) prompted a survey of members of the Child Neurology Society regarding aspects of the diagnosis and management of this disorder. Major findings of those responding to this survey (26% response rate) were as follows: (1) 93% believed that a diagnosis of PVS can be made in children, but only 16% believed that this applied to infants younger than 2 months and 70% in the 2-month to 2-year group; (2) a period of 3 to 6 months was believed to be the minimum observation period required before a diagnosis of PVS could be made; (3) 86% believed that the age of the patient would affect the duration of time needed to make the diagnosis of PVS; (4) 78% thought a diagnosis of PVS could be made in children with severe congenital brain malformations; (5) 75% believed that neurodiagnostic studies would be of value and supportive of the clinical diagnosis of PVS; (6) members' opinions as to the average life expectancy (in years) for the following age groups after the patients were considered vegetative were: newborn to 2 months, 4.1; 2 months to 2 years, 5.5; 2 to 7 years, 7.3; and more than 7 years, 7.4; (7) 20% believed that infants and children in a PVS experience pain and suffering; and (8) 75% "never" withhold fluid and nutrition from infants and children in a PVS and 28% "always" give medication for pain and suffering.(ABSTRACT TRUNCATED AT 250 WORDS)     

Altered resting state effective connectivity in long-standing vegetative state patients: An EEG study

ObjectiveRecent evidence mainly based on hemodynamic measures suggests that the impairment of functional connections between different brain areas may help to clarify the neuronal dysfunction occurring in patients with disorders of consciousness (DOC).The aim of this study was to evaluate effective EEG connectivity in a cohort of 18 patients in a chronic vegetative state (VS) observed years after the occurrence of hypoxic (eight) and traumatic or hemorrhagic brain insult.Methodswe analysed the EEG signals recorded under resting conditions using a frequency domain linear index of connectivity (partial directed coherence: PDC) estimated from a multivariate autoregressive model. The results were compared with those obtained in ten healthy controls.ResultsOur findings indicated significant connectivity changes in EEG activities in delta and alpha bands. The VS patients showed a significant and widespread decrease in delta band connectivity, whereas the alpha activity was hyper-connected in the central and posterior cortical regions.ConclusionThese changes suggest the occurrence of severe circuitry derangements probably due to the loose control of the subcortical connections. The alpha hyper-synchronisation may be due to simplified networks mainly involving the short-range connections between intrinsically oscillatory cortical neurons that generate aberrant EEG alpha sources. This increased connectivity may be interpreted as a reduction in information capacity, implying an increasing prevalence of stereotypic activity patterns.SignificanceOur observations suggest a remarkable rearrangement of connectivity in patients with long-standing VS. We hypothesize that in persistent VS, after a first period characterized by a breakdown of cortical connectivity, neurodegenerative processes, largely independent from the type of initial insult, lead to cortex de-afferentation and to a severe reduction of possible cortical activity patterns and states.     

过度高压氧治疗对缺氧性脑病所致持续性植物状态预后的影响

目的研究过度高压氧治疗(HBO)对缺氧性脑病所致的持续性植物状态(PVS)患者预后的影响,探讨高压氧的治疗机制及过度治疗的不良影响。方法收集我院收治的缺氧性脑病致PVS患者60例,根据其高压氧治疗的病史分为常规HBO组,超长HBO组,未接受HBO治疗对照3组。以发病后6个月为观察点。观察指标包括PVS意识及预后评分(南京2001年版);改良Ashworth量表(MAS)评定;日抽搐次数;头CT/MRI中第三脑室宽度;颅内压;脑电图等。结果获得随访51例。3组患者在年龄、患病时间、意识及脑电图无显著性差异。第三脑室宽度及颅内压数据分析,超长HBO组的第三脑室宽度明显大于常规HBO组与对照组,同时颅内压较低,且这种差异在预后恢复有显著性差异(P0.05)。肌张力评定提示对照组及常规HBO组统计学分析无显著性差异。但与超长HBO组肌张力明显高于其他组,有显著性差异(P0.05)。超长组中抽搐次数较其他2组增加,但无统计学差异。结论高压氧治疗对脑损伤后意识恢复具有一定的疗效,但过度高压氧治疗可能导致脑昏迷患者严重的脑萎缩、巨大脑室及低颅压状态。形成不可逆、迟发性脑损伤,影响意识恢复。因此需合理、规范应用高压氧治疗。