Long-latency auditory-evoked potentials in severe traumatic brain injury.

OBJECTIVE: To detect the effects of different deviant stimuli on long-latency auditory-evoked potentials (LLAEPs) in patients with severe impairment of consciousness from traumatic brain injury (TBI) and to define their prognostic value for late functional outcome. DESIGN: Correlational study on a prospective cohort. SETTING: Brain injury rehabilitation center. PATIENTS: Eleven volunteers and 21 consecutively sampled patients with severe TBI referred to the inpatient intensive rehabilitation unit of primary care in a university-based system. MAIN OUTCOME MEASURES: The LLAEPs recorded with different paradigms; and the Glasgow Outcome Scale (GOS), Disability Rating Scale (DRS), FIMtrade mark instrument, and Neurobehavioural Rating Scale (NBHRS). RESULTS: N100-P150 complex showed high reliability. Patients with good outcomes showed N100 and P150 mean latencies similar to those of unimpaired patients and shorter than patients with unfavorable outcomes. When the deviant stimulus was the patient's name, N100 latency showed high correlations with DRS (p <.007), FIM (p <.01), and NBHRS (p <.009). P250 and P300 showed a low percentage of occurrence with passive paradigms in both patients and controls. Their scores were inversely correlated to the Glasgow Coma Scale (p <.03) and the Innsbruck Coma Scale (p <.003), but no significant correlations were found with functional and behavioral outcomes. Patients with GOS score 1-2 1 year posttrauma had significantly longer latency and lower amplitude of N100 and P150 than those with GOS score 4-5. CONCLUSIONS: LLAEPs can be recorded in patients with severe impairment of consciousness by means of passive paradigms. The use of a stimulus that is relevant for the patient can enhance the accuracy of the test and its relationship with functional outcome.

Simian virus-40 sequences are a negative prognostic cofactor in patients with malignant pleural mesothelioma.

Several biochemical and clinical factors have been shown to correlate with survival in human malignant pleural mesothelioma (MM). Nevertheless, average survival of 4 to 10 months from diagnosis is sometimes not sufficient for full expression of these factors. Several studies have reported SV40 sequences in MM, suggesting a possible pathogenic role. We investigated whether the presence of these sequences had any effect on MM patient survival. For this study, we used polymerase chain reaction and Southern blot analysis to search for and identify SV40 DNA in biopsy samples from 83 MM patients. These cases were divided according to histology: 62/83 (74. 7%) had epithelioid morphology (EMM) and 21/83 (25.3%) had either biphasic or sarcomatous morphology (B/SMM). SV40 positivity was significantly associated with B/SMM growth pattern (chi-squared test = 5.03, P = 0.025). Kaplan-Meier univariate analysis confirmed the independent effect of histology on MM survival (log-rank test = 13.9, P < 0.001) and showed a trend for increased survival in SV40-negative patients (log-rank test = 2.83, P = 0.09). Most importantly, Cox's regression model showed that SV40-positive status affected the predictive value of histology on patient survival. In particular, when SV40 expression was added to the B/SMM histotype, Cox's regression model showed a significant increase in hazard ratio (HR) with respect to SV40-negative B/SMM (HR = 4.25, 95% CI = 2.00-9. 00, likelihood ratio test = 14.31, P < 0.001). We conclude that SV40 expression is significantly associated with B/SMM histology and represents an important prognostic cofactor when associated with the tumor subtype in MM patients.

Somatosensory and motor evoked potentials at different stages of recovery from severe traumatic brain injury.

OBJECTIVE: To detect changes of somatosensory evoked potentials (SEPs) and motor evoked potentials (MEPs) at different stages of recovery from severe brain injury and to determine whether they can be used to predict late functional outcome. DESIGN: Correlational study on a prospective cohort. SETTING: Brain injury rehabilitation center. PATIENTS: Twenty-seven consecutively sampled patients with severe traumatic brain injury referred to the inpatient intensive rehabilitation unit of primary care in a university-based system. MAIN OUTCOME MEASURES: (1) Glasgow Outcome Scale, Disability Rating Scale, and Functional Independence Measure; (2) SEPs and MEPs from upper limbs (ULs) and lower limbs (LLs). Outcome was assessed at 6 and 12 months after trauma. Correlations were computed with the nonparametric test of Spearman-Rank. RESULTS: Both SEPs and MEPs showed dynamic changes (p < .02 for N20, p < .05 for N30, P40, and N45), with a trend toward a progressive normalization. N30 was more frequently abnormal than N20. SEPs from LLs were more frequently and more persistently abnormal than those from ULs. Clinical and functional outcome was strongly correlated with the degree of abnormality of SEPs from LLs (p < .002), whereas only mild relationships were found with SEPs from ULs. Both SEPs and MEPs showed a high negative predictive value (83% for N30 and 83% for P40), but only SEPs from LLs also had a high positive predictive value (72% for P40). Sensitivity was 88% both for N30 and P40. Specificity was 50% for N30 and 70% for P40). CONCLUSION: SEPs from LLs can be very useful in monitoring the postacute phase of traumatic brain injury and in identifying patients who require further intensive rehabilitation. MEPs may be of questionable value.

H-reflex changes in the course of amyotrophic lateral sclerosis.

In this study the H-reflex and M-wave were evoked in a group of ALS patients, to correlate the findings with the clinical state, and to investigate whether a statistical approach for assessing H-reflex changes in the presence of a constant M-wave could be reproducible and helpful in monitoring the course of amyotrophic lateral sclerosis (ALS). The H-reflex and M-wave from the soleus muscle were evoked at different stimulus strengths in 35 patients with definite ALS during the course of their illness. The mean amplitude of the H-reflexes (H-mean) obtained in different sessions within an established range of mean M-response amplitude (M-mean) was calculated. For each patient, M-mean was made constant across sessions. H-mean showed high reproducibility and two different trends of changes which emerged in a 1 year follow-up within the population: a significant progressive increase and a steady decrease. When grouped on the basis of their H-mean trend, the patients did not differ in terms of any clinical variables considered. However, the group with progressive increase of H-mean showed a better prognosis. This study has shown that H-mean is effective in assessing the clinical course of ALS and could be useful in monitoring drug effects during clinical trials.