Prognostic predictors of thalamic hemorrhage.

BACKGROUND AND OBJECTIVE: There is no study evaluating the role of clinical, evoked potential and radiological parameters in the prognosis of thalamic hemorrhage employing multivariate logistic regression analysis, thus we aimed to evaluate the role of these parameters in predicting the 3 month outcome following thalamic hemorrhage. SETTING: Tertiary care referral teaching hospital. METHODS: Fifty-three patients with CT proven thalamic hematoma were evaluated. Conscious level was assessed using the Glasgow Coma Score (GCS), severity of stroke by the Canadian Neurological Scale (CNS), while muscle tone, tendon reflexes and power were also recorded. Hematoma size and type, and evidence of ventricular extension were obtained from the CT scan. Hematomas were classified as (A) thalamic with postero-lateral extension or (B) thalamic without postero-lateral extension. Central motor conduction to upper limb and median somatosensory evoked potentials (SEP) were recorded. Outcome was defined at 3 months on the basis of the Barthel Index (BI) with good being a BI of 12 or greater and poor a BI of less than 12. Best predictors of outcome were evaluated by single variable logistic regression analysis followed by multivariate logistic regression. RESULTS: Age ranged between 35 and 85 years; 18 were women. Mean GCS was 10.4 and CNS was 3.9. Thirty-one patients had type A hematomas and 22 type B. The hematoma was small in 5, medium in 35 and large in 13 patients. Ventricular extension was present in 34 patients. Motor evoked potentials were unrecordable in 36 and central motor conduction time was prolonged in 8 patients. Median SEP was unrecordable in 37 and N9-N20 conduction time was prolonged in 2 patients. At 3 months, 8 patients had died, 24 had good and 21 had poor outcome. On univariate logistic regression analysis diabetes mellitus, GCS, pupillary asymmetry, CNS score, type and size of hematoma and motor and somatosensory evoked potentials were significant in relation to outcome. On multivariate logistic regression analysis, the best predictors of outcome at 3 months were the type of hematoma and CNS score. CONCLUSION: CNS score and CT appearance of hematoma are the best predictors of 3 month outcome following thalamic hemorrhage. The proposed model for outcome assessment is simple and easy to apply and could have wide clinical application.     

Predictive value of P300 event-related potentials compared with EEG and somatosensory evoked potentials in non-traumatic coma

Developments in ethical decision making are increasing demand for more accurate predictions of outcome in coma. New neurophysiologic tests are needed to improve the ability to predict awakening as well as poor outcome. We have recently reported that the P300 event-related potential (P300) correlates with awakening and depth of nontraumatic coma. In this companion study, the predictive value of the P300 was compared with median nerve somatosensory evoked potentials (SEP) and EEG in 20 patients in non-traumatic coma. We also evaluated the predictive value of a simplified grading scale for both the EEG and SEP (the USC SEP scale and USC EEG scale). The resence of a P300 was significantly associated with higher Glasgow coma scores (GCS) and awakening. Severe abnormalities of the somatosensory evoked potentials significantly correlated with the absence of awakening and a low GCS. Moderate abnormalities of the SEP were significantly associated with awakening and higher GCS scores. the EEG was significantly associated with GCS score and severe abnormalities of the EEG were predictive of the absence of awakening and very low GCS scores. The data indicates that the P300 and SEP are more effective than the EEG in predicting awakening, and that the SEP and EEG are more effective than the P300 in predicting poor outcome. We conclude that, in addition to EEG and SEP, the P300 should be considered in the prognostic evaluation of patients in nontraumatic coma. Further, simplified scales for the EEG and SEP are predictive of depth of coma and outcome.     

Motor and somatosensory evoked potentials in tuberculous meningitis: a clinico-radiological correlation

OBJECTIVE: The sensory and motor functions in severe tuberculous meningitis (TBM) may be difficult to assess clinically and may be helped by evoked potential studies. Lack of motor and somatosensory evoked potential studies in TBM prompted the present study. METHODS: All the patients with TBM underwent detailed neurological evaluation and cranial CT scan study. Motor and somatosensory evoked potentials to both upper and lower limbs were carried out bilaterally. The outcome was defined on the basis of 3 month Barthel Index (BI) score into good (BI > 12) and poor (BI < 12). RESULTS: Forty-one highly probable patients with TBM whose ages ranged between 8 and 64 years and 14 of whom were females were included in this study. Twenty-three patients were in stage III (meningitis, neurological signs and altered sensorium), 12 in stage II (meningitis with neurological sign) and the remaining patients were in stage I (meningitis only). Cranial CT scan was carried out in all and MRI in 18 patients. On CT scan hydrocephalus was present in 21, infarction in 14 and tuberculoma in 4 patients. Motor evoked potential (MEP) was abnormal in 18 patients (36 limbs) and SEP in 9 patients (23 limbs). Upper limb central motor conduction time to abductor digiti minimi (CMCT-ADM) was abnormal in 15 and that to tibialis anterior (TA) in 21 limbs. CMCT abnormality was lateralized in 6 and only upper or lower limbs were involved in 11 patients. The SEP abnormalities were lateralized in 2 patients and only upper or lower limbs were involved in 3. The MEP changes correlated with stage of TBM and outcome whereas SEP with outcome only. CONCLUSION: Motor and somatosensory evoked potentials may be helpful in objective documentation of respective motor and sensory functions in TBM patients with altered sensorium.     

Prognosis of conservatively treated patients with Pott's paraplegia: logistic regression analysis

OBJECTIVE: To evaluate the prognostic significance of various clinical, radiological, and neurophysiological findings in conservatively treated patients with Pott's paraplegia, using multiple regression analysis. METHODS: The study included 43 patients with Pott's paraplegia, managed conservatively. The diagnosis of Pott's spine was based on clinical, magnetic resonance imaging, and computed tomography or ultrasound guided aspiration biopsy. All patients were examined clinically, and motor evoked potentials (MEPs) to lower limbs and tibial somatosensory evoked potentials (SEP) were recorded. Outcome at six months was defined as good or poor. For evaluating predictors of outcome, 15 clinical, investigative, and evoked potential variables were analysed, using multiple logistic regression analysis. RESULTS: The age range of the patients was 16-70 years, and 22 were female. Mild spasticity with hyperreflexia only was seen in 13 patients. In the remaining, weakness was severe in eight, and moderate and mild in 11 patients each. Twenty patients had loss of joint position sensation. MEP and SEP were abnormal in 19 and 18 patients, respectively. On multiple regression analysis, the best model predicting six month outcome included power, paraplegia score, SEP, and MEP. CONCLUSION: Patients with Pott's paraplegia are likely to recover completely by six months if they have mild weakness, lower paraplegia score and normal SEPs and MEPs.     

Clinical relevance of long-latency SEPs and VEPs during coma and emergence from coma

Follow-up measurements of long-latency visual (VEP) and somatosensory (SEP) evoked potentials were performed on 30 comatose patients. Twenty-seven of the patients had severe head injury, 2 had encephalitis and 1 was in a posthypoxic state. For the SEP study a mechanical vibration stimulus was used, applied 60 times at intervals of 10 sec. The same rate was used for visual stimulation. The late EP components were classified by a signal-to-noise ratio (SNR), whereby an SNR of less than 2.6 is characteristic of a questionable or unmeasurable EP and an SNR greater than 2.6 is evidence of a clearly existing EP; the clinical state was scored using the Glasgow Coma Scale (GCS); the patient outcome was assessed 6 months after the injury using the Glasgow Outcome Scale. The highest correlation (r = 0.72) was found between the clinical state, represented by the GCS, and the SEP. A similar correlation (r = 0.66) was obtained between the GCS and the vertex VEP. The occipital VEP showed no correlation. Emergence from coma and recovery was accompanied by an increase of the SEP and an increasing spread of the VEP over the whole scalp. Most patients with a clear long-latency SEP in coma had a favourable outcome; a missing or a questionable SEP indicated a poor outcome.     

Effect of methyl prednisolone on sensory motor functions in tuberculous meningitis

A prospective hospital based study was undertaken to study the effect of methyl prednisolone therapy on sensory and motor functions in tuberculous meningitis (TBM). The patients with TB meningitis seen during 1994-1998 were studied. CT scan, motor evoked potential (MEP) to upper and lower limbs; and median and tibial somatosensory evoked potentials (SEP) were carried out in all the patients. Outcome was defined at the end of 3 months into poor, partial or complete recovery on the basis of Barthel index score. Inj methyl prednisolone (MPS) 500 mg IV was given to 21 patients followed by oral tapering dose of prednisolone over one month in addition to 4 drug anti-tubercular treatment. The control group comprised of 16 patients who received 4 drugs anti-tubercular therapy without any corticosteroid. These groups were comparable with respect to their age, stage of meningitis, Glasgow coma scale score and radiological findings. In MPS group, CMCT was abnormal in 9 and SEPs in 7 patients. In the control group, these were abnormal in 9 and 5 patients respectively. Three months after the therapy the frequency of improvement, deterioration and stationary evoked potential (EP) changes were also noted in both the groups. Diversity of evoked potential changes were also noted. Evoked potential changes were neither significantly different between the groups nor there was any beneficial effect shown in MPS group at 3 months. On the contrary, the control group fared significantly better than the MPS group. Initial MEP and SEP abnormalities were however related to 3 months outcome (p<0.01).     

Evoked potentials for the prediction of vegetative state in the acute stage of coma

For comatose patients in intensive care units, it is important to anticipate their functional outcome as soon and as reliably as possible. Among clinical variables the Glasgow Coma Score (GCS) and the patient's pupil reactivity are the strongest predictive variables. Evoked potentials help to assess objectively brain function. Over the past 20 years, numerous studies have assessed their prognostic utility in terms of awakening from coma. Fewer studies, however, have focused upon the utility of evoked potentials in predicting progression to the vegetative state. In this area evoked potentials appear to have a highly predictive value. In anoxic coma the abolition of somatosensory evoked potentials (SEPs) is related to a poor outcome, defined as death or survival in a vegetative state, with a 100% specificity. Following traumatic brain injury, the predictive value for unfavourable outcome is 98.5% when there are no focal injuries likely to abolish SEP cortical components. In contrast, the presence of event-related evoked potentials, and particularly mismatched negativity (MMN), is a strong predictor of awakening and precludes comatose patients from moving to a permanent vegetative state (PVS).     

Early prognosis in coma after cardiac arrest: a prospective clinical, electrophysiological, and biochemical study of 60 patients.

BACKGROUND: The univariate study of clinical, electrophysiological, or biochemical variables has been shown to predict the outcome in postanoxic coma in about 50% of patients for each type of variable. Previous studies did not, however, consider the prognostic accuracy of a multivariate approach. METHODS: Sixty patients in coma for more than six hours after cardiac arrest were prospectively examined by means of repeated clinical examinations (including Glasgow coma score (GCS)), EEG, and medianus nerve somatosensory evoked potentials (SEPs). In 16 patients, the early concentrations of serum neuron specific enolase and ionised calcium were also measured. RESULTS: Within the first year after cardiac arrest, 20% of patients made a good neurological recovery; 80% remained in a vegetative state or died. Clinical examination correctly predicted outcome in 58% of patients, SEP in 59%, and EEG in 41%. The combination of clinical examination, SEP, and EEG raised the percentage of correct predictions to 82%, without false pessimistic predictions. Concentrations of serum neuron specific enolase and ionised calcium were of no additional prognostic help. Multivariate regression analysis identified the association of GCS < 8 at 48 hours with abnormal or absent early cortical SEPs as highly predictive of a bad outcome (risk = 97%, 95% confidence interval = 86-99%). CONCLUSION: The combination of GCS at 48 hours, SEP, and if these are non-conclusive, EEG, permits a more reliable prediction of outcome in postanoxic coma than clinical examination alone.     

Diffuse axonal injury A clinical and computerised tomography study of 128 patients

A study of clinical, computerised tomography (CT) profile and outcome was made of 128 patients, diagnosed to have diffuse axonal injury based on CT criteria. The mean age was 26 years. A lucid interval was present in 37 patients and hypoxia and/or hypotension was present in 43 patients. The depth of "marker lesions" in CT correlated with Glasgow Coma Score (GCS) (p<0.02) and duration of coma (p<0.01). The presence of associated intracranial haematoma >25 ml portended an adverse outcome. A logistic regression analysis revealed age, GCS, state of perimesencephalic cisterns and pupillary dilation to be independent predictors of poor outcome. Residual sequelae (focal deficits, cognitive deficits, postconcussion syndrome) were evident in nearly half of patients with diffuse axonal injury (DAI) and a lucid interval.     

Evaluation of combination therapy using aciclovir and corticosteroid in adult patients with herpes simplex virus encephalitis

OBJECTIVE: Herpes simplex virus encephalitis (HSVE) is associated with significant morbidity and mortality, even with appropriate antiviral therapy. In the present investigation, the first to assess efficacy of corticosteroid treatment with aciclovir therapy in HSVE, multiple logistic regression analysis was performed of predictors of outcome in adult patients with HSVE. METHODS: A non-randomised retrospective study of 45 patients with HSVE treated with aciclovir was conducted. The patients were divided into poor and good groups based on outcome at three months after completion of aciclovir treatment. The variables evaluated were: clinical variables (sex, age, days after onset at initiation of aciclovir, Glasgow Coma Scale (GCS) at initiation of aciclovir, initial and maximum values for the cell numbers and protein concentration in the cerebrospinal fluid, and corticosteroid administration); neuroradiological variables (detection of lesions by initial cranial computed tomography and by initial magnetic resonance imaging); and one neurophysiological variable (detection of periodic lateralised epileptiform discharges on the initial electroencephalogram). Single variable logistic regression analysis was performed followed by multiple logistic regression analysis. The best set of predictors for the outcome of HSVE was estimated by stepwise logistic regression analysis. RESULTS: A poor outcome was evident with older age, lower GCS score at initiation of aciclovir, and no administration of corticosteroid. Patient age, GCS at initiation of aciclovir, and corticosteroid administration were found to be significant independent predictors of outcome on multiple logistic regression analysis, and these three variables also formed the best set of predictors (R(2) = 0.594, p<0.0001). CONCLUSION: Combination therapy using both aciclovir and corticosteroid represents one of the predictors of outcome in HSVE.     

体感诱发电位对亚低温治疗重型颅脑创伤临床疗效的评估

目的 探讨体感诱发电位对亚低温治疗重型颅脑创伤患者临床疗效的评估价值。方法55例经手术治疗后的重型颅脑创伤患者,随机分为亚低温治疗组和对照组。亚低温治疗组于手术后施以亚低温治疗,直肠温度降至33℃～35℃;对照组体温维持在36.5℃～37.5℃。共治疗3～7d,分别于术后第1d及第8d对两组患者进行GCS疗效和体感诱发电位评估;6个月后进行GOS预后评估。结果 亚低温组患者经治疗后,GCS评分及体感诱发电位测定结果均优于对照组(均P<0.05);随访6个月亚低温组患者GOS预后评估也优于对照组(P<0.05)。结论 亚低温是治疗重型颅脑创伤的有效手段之一,而体感诱发电位是评估颅脑创伤预后的客观指标之一。     

Predictors of long-term neurological sequelae of tuberculous meningitis: a multivariate analysis

There is paucity of studies on predictors of long-term sequelae of tuberculous meningitis (TBM). We report the neurological sequelae of TBM at 1 year and their predictors. Patients with TBM who were followed up for 1 year were included. The diagnosis of TBM was based on clinical, cerebrospinal fluid (CSF) and computed tomography (CT) scan findings. Detailed neurological examinations at admission and at 1 year were carried out. All the patients received four-drug antitubercular therapy. The frequency of sequelae at 1 year were noted and the role of various demographic (age, sex, duration of illness, BCG vaccination), clinical (weakness, seizure, extra central nervous system tuberculosis, Glasgow Coma Scale (GCS) score, cranial nerve palsy, stage, corticosteroid, drug-induced hepatitis, shunt surgery), and laboratory findings (erythrocyte sedimentation rate (ESR), CSF cell and protein, CT scan evidences of hydrocephalus, basal exudates, infarctions and tuberculoma) at presentation were evaluated employing logistic regression analysis. Sixty-five patients with TBM were included in this study whose age ranged between 13 and 80 years (mean 33.2), 27 of whom were females. Complete neurological recovery at 1 year occurred in 21.5% patients only although about 50% were independent for activities of daily living. Neurological sequelae were observed in 78.5% patients, which included cognitive impairment in 55%, motor deficit in 40%, optic atrophy in 37% and other cranial nerve palsy in 23%. On logistic regression analysis, focal motor deficit at admission was the most important predictor of neurologic deficits at 1 year. GCS score predicted the cognitive and motor sequelae. Neurological sequelae at year occurred in 78.5% patients with TBM in the form of cognitive impairment, motor deficit and optic atrophy. Sequelae were common in patients who had focal motor deficit and altered sensorium at admission.     

Prediction of 'awakening' and outcome in prolonged acute coma from severe traumatic brain injury: evidence for validity of short latency SEPs.

OBJECTIVE: To evaluate the prognostic value of somatosensory evoked potentials (SEPs) in severe traumatic brain injury (TBI) considering both 'awakening' and disability. METHODS: SEPs were recorded in 60 severe TBI with duration of acute coma>7 days. N20-P25 amplitudes, their side-to-side asymmetry and CCT were measured. SEPs on each hemisphere were classified as normal (N), pathological (P) or absent (A). 'Awakening' and disability were assessed after at least 12 months using Glasgow Outcome Scale (GOS). SEP predictive value was compared with GCS and EEG reactivity RESULTS: Seventy-five percent regained consciousness. 29/60 had a good outcome (GOS 4-5) and 31/60 had a bad outcome (GOS 1-3). According to the ROC curve, SEP findings were classified in 3 grades. Grade I (NN, NP) had PPV of 93.1% for 'awakening' and 86.2% for good outcome. Grade III (AA) had PPV of 100% for bad outcome and 72.7% for 'awakening'. Grade II (PP, NA, PA) was associated with the wider range of outcome. A multivariate analysis including SEP grading, GCS and EEG reactivity did not increase the percentage of cases prognosticated by SEP alone. CONCLUSIONS: We confirm the high predictive value of SEPs in TBI, which is greater than GCS and EEG reactivity. Indeed, SEP grades I and III were able to predict the correct prognosis in more than 80% of severe TBI. Therefore, SEPs should be used more widely in the prognosis of severe TBI. SIGNIFICANCE: Differently from post-anoxic, in post-traumatic coma the presence of normal SEPs has a favourable predictive value both for 'awakening' and disability. We think that in literature enough attention has still not been paid to this finding.     

Postanoxic alpha (theta) coma: a reappraisal of its prognostic significance.

OBJECTIVES: To appraise the controversial prognostic significance of postanoxic alpha or theta coma (ATC). METHODS: We prospectively assessed 14 comatose patients with ATC after cardiac arrest by means of a protocol which included repeated clinical examinations, EEG, and median somatosensory evoked potentials (SEP). Good outcome was defined by the reappearance of cognition (Glasgow outcome scale 3-5) at any time during the 1 year follow-up. RESULTS: Nine of 14 patients had a monotonous, frontally accentuated and a reactive alpha (theta) EEG activity (complete ATC). In these patients ATC was recorded a mean of 47 h after resuscitation, the mean Glasgow coma scale (GCS) was 4 at 48 h, and early cortical SEPs were altered or absent in 5 of 7 patients. All nine patients died. In five of 14 patients the alpha (theta) EEG activity was either not monotonous, partially reactive or posteriorly dominant (incomplete ATC). In these patients ATC was recorded a mean of 43 h after resuscitation, the mean GCS was 8 at 48 h, and early cortical SEP were normal in 4 of 5 patients. Three of 5 patients regained cognition, two of them remained however dependent in activities of everyday life. CONCLUSIONS: This study and a review 283 cases of postanoxic ATC reported in the literature suggest the existence of incomplete and complete variants of postanoxic ATC. Whereas complete ATC is invariably associated with a poor outcome, full recovery is possible in patients with incomplete ATC. The combination of EEG, clinical, and SEP findings improves the prognostic accuracy of postanoxic ATC.     

Clinical and computed tomographic comparisons of analysis of the condition in children with brain injury of 13-15 scores by the Glasgow Coma Scale on admission to hospital

Clinical and computed tomographic comparisons were made in 590 children with mild brain injury (BI). The children admitted for BI of 13-15 scores assessed by the Glasgow coma scale (GCS) in the first hour after injury were examined. They all underwent brain computed tomography (CT), skull X-ray study, and neurological studies. Their history data were analyzed. 73% of the children were admitted within the first 12 hours following injury. Falling from the growth height was mainly responsible for BI (45.2%). The frequency of the CT signs of BI was 36.3%. Surgical treatment was required in 5.8% of the children; among them 4.4% and 1.4% were operated on for depressed fractures and intracranial hematomas, respectively. A relationship was found between the presence of the CT signs of BI and the GCS scores on admission. With 15 and 13 GCS scores, the positive CT pattern was detected in 16 and 70% of cases. Well-defined focal neurological symptoms and multiple vomiting (38 and 57%, respectively) are predictors of acute pathology on a CT scan. X-ray skull fracture increases the likelihood of CT pathology up to 62%. Consciousness disturbance of as high as 13-14 GCS score concurrent with noticeable neurological symptoms and skull fracture increases the probability of the positive CT pattern up to 93%. X-ray and CT studies did not reveal acute traumatic injuries when there were traces of skull injury in the presence of clear consciousness and in the absence of vomiting.     

A mathematical outcome prediction model in severe head injury: a pilot study

103 patients of head injury, with a Glasgow coma scale (GCS) score of 8 or less, were studied prospectively. GCS score, brain stem reflexes, motor score, reaction level scale, and Glasgow Liege scale were evaluated as prognostic variables. Linear logistic regression analysis was used to obtain coefficients of these variables and mathematical formulae developed to predict outcome in individual patients.     

脑电图、经颅多普勒超声、体感诱发电位检测对昏迷患者脑功能评判的价值

目的探讨脑电图(EEG)、经颅多普勒超声(TCD)、体感诱发电位(SEP)检测对昏迷患者脑功能评判的价值。方法采用EEG、TCD、SEP3种检测方法,对72例昏迷患者(浅昏迷12例,中度昏迷17例,睁眼昏迷4例,深昏迷39例)进行检测脑功能并评分。结果首次检测EEG25例呈电静息、TCD28例无血流信号、SEP26例P14皮质电位消失,均在深昏迷组。复查EEG时17例最终为电静息;另有24例TCD具有振荡波、钉子波频谱改变。脑功能评分:EEGV级42例、Ⅳ级10例、Ⅲ级14例;TCDV级28例、Ⅳ级9例、Ⅲ级6例、Ⅱ级9例;SEPⅢ级27例。死亡28例及多种原因放弃治疗的25例患者以深昏迷组为多。结论昏迷程度越深,EEG、TCD、SEP分级越高,预后越差;EEG、TCD、SEP检测对评价昏迷患者脑功能状态、预测预后提供了客观、可靠的依据。     

A study of prognostic predictors of supratentorial haematomas

The prognosis of supratentorial haematomas is based on clinical signs and radiological features. The role of evoked potentials has not been evaluated systematically. In a prospective study of supratentorial haemorrhage a number of clinical (17), radiological (3) and evoked potential (2) parameters were evaluated employing univariate logistic regression analysis in 69 patients and multivariate logistic regression stepdown analysis in 51 patients. The outcome was graded on the basis of the Barthel index (BI) score at 3 months as good (BI 12) or poor (death or BI < 12) recovery. Employing univariate analysis the significant prognostic variables were Glasgow Coma Scale, Canadian Neurological Scale, tendon reflex, associated medical complications, urinary incontinence, ventricular extension of the haematoma and motor evoked potentials. Using multivariate logistic regression analysis the best set of parameters in relation to outcome inlcuded Glasgow Coma Scale (P < 0.05), Canadian Neurological Scale (P < 0.05), tendon reflex (P < 0.1), ventricular extent (P < 0.01) and motor evoked potentials (P < 0.05). From this study it is concluded that, in addition to clinical and radiological parameters, motor evoked potentials also have an important role in predicting outcome.     

Predictive value of neurological examination for early cortical responses to somatosensory evoked potentials in patients with postanoxic coma

Bilateral absence of cortical N20 responses of median nerve somatosensory evoked potentials (SEP) predicts poor neurological outcome in postanoxic coma after cardiopulmonary resuscitation (CPR). Although SEP is easy to perform and available in most hospitals, it is worthwhile to know how neurological signs are associated with SEP results. The aim of this study was to investigate whether specific clinical neurological signs are associated with either an absent or a present median nerve SEP in patients after CPR. Data from the previously published multicenter prospective cohort study PROPAC (prognosis in postanoxic coma, 2000–2003) were used. Neurological examination, consisting of Glasgow Coma Score (GCS) and brain stem reflexes, and SEP were performed 24, 48, and 72 h after CPR. Positive predictive values for predicting absent and present SEP, as well as diagnostic accuracy were calculated. Data of 407 patients were included. Of the 781 SEPs performed, N20 s were present in 401, bilaterally absent in 299, and 81 SEPs were technically undeterminable. The highest positive predictive values (0.63–0.91) for an absent SEP were found for absent pupillary light responses. The highest positive predictive values (0.71–0.83) for a present SEP were found for motor scores of withdrawal to painful stimuli or better. Multivariate analyses showed a fair diagnostic accuracy (0.78) for neurological examination in predicting an absent or present SEP at 48 or 72 h after CPR. This study shows that neurological examination cannot reliably predict absent or present cortical N20 responses in median nerve SEPs in patients after CPR.     

体感诱发电位在急性脑卒中后的变化观察和意义探讨

目的观察急性脑卒中患者体感诱发电位（SEP）改变特点，评价其对于脑功能监测的价值。方法对58例脑梗死、27例脑出血和11例蛛网膜下腔出血患者，检测发病后不同时期（1～12d）SEP和血清神经元特异性烯醇化酶（NSE）改变，结合中国卒中量表评分（CSS）、Barthel指数、Glasgow-Pittsburgh昏迷量表评分以及颅脑影像学检查结果，分析与临床神经功能缺失的关系。25例年龄和性别匹配的正常人作为对照。结果发病后4d内各型脑卒中患者的SEP—P15、N20、P25和P40峰潜伏期较正常对照显著延长（P〈0．01）。脑出血和脑梗死患者发病后4d内SEP异常率高于发病后5～12d测定结果。发病后4d内，幕下脑出血和后循环脑梗死患者SEP—N20峰潜伏期与其病灶大小呈正相关（P〈0．01）。脑出血和脑梗死患者SEP—N20峰潜伏期与其血清NSE水平和CSS评分呈正相关（P〈0．01）。各型脑卒中患者SEP—N20峰潜伏期与其Glasgow-Pittsburgh昏迷量表评分呈负相关（P〈0．01）。结论SEP—N20峰潜伏期异常反映脑出血和脑梗死患者脑损伤和神经功能缺失严重程度，并可作为评估蛛网膜下腔出血患者昏迷程度的指标。