| BackgroundThe midline structure of brain is very complicated, including the cerebral falx, septum pellucidum, the third ventricle, pineal gland, brain stem, etc. The midline structure is the channel of afferent and efferent nerve, playing an important role in the nervous system. The midline shift is common complication of neurocritical patients and can be found in stroke, brain tumor, brain trauma, etc. MLS is closely related to the level of consciousness, intracranial pressure and clinical prognosis. Brain midline shift is lift-threatening condition. It was reported that horizontal displacement of the pineal body of 0 to 3 mm from the midline in patients with acute unilateral cerebral masses was associated with alertness,3 to 4 mm with drowsiness, 6 to 8.5 mm with stupor, and 8 to 13 mm with coma. Pullicino et al. found that both ML S (P=0.001) and coma (P=0.019) were independent predictors of mortality at 15 days following acute stroke. MLS of> or=4 mm on a scan performed within 48 hours of stroke onset identified patients with a low probability of 14-day survival (0.16; CI 0 to 0.32) with a specificity of 89% and a sensitivity of 46%.To evaluate the relationship between the degree of midline shift by Computed Tomography (CT) finding and Glasglow Coma Score (GCS) in patients after head injury, Chiewvit et al. retrospectively review 216 consecutive cases of traumatic head injury and found that the increased degree of midline shift in patients with head injuries by CT scan was related to the severity of head injury (GCS=3-12) and was significantly related to poor final clinical outcome. Similarly, a multivariate analysis of a cohort of over 10,000 TBI patients showed that the compression of the third ventricle and a ML S>0.5 cm were both major predictors of mortality within the first 15 days after injury. Therefore, the monitoring of midline structure shift is helpful to the observation of disease development and the setting of treatment. It is one of the key factors to the recovery of neurocritical patients.At present, the midline shift mainly measured by head computerized tomography. The head CT is considered to be the gold standard to diagnose MLS. Serial CTs can provide powerful evidences for the patients’treatment. However, patients must be transported to the imaging department for head CT examination. The transportation may cause the patients’ condition aggravation because the increased the intracranial pressure and hypoxic et. al. In 1990, Andrew etc. showed that there was significant correlation between increased frequency of insults post-transfer (compared with pre-transfer) and high injury severity score. A greater proportion of the patients transported from the emergency department had secondary injuries post-transfer. Adequate resuscitation before moving the patient, especially in patients with multiple injury, is important. Serial CTs can be associated with significant morbidity related to patients’transportation and their value has, therefore, been questioned. It is necessary to explore a non invasive, quickly available, repeatable and reliable technique that allows the monitoring of MLS at bedside.Before the advent of computed tomography (CT) in the 1970 s, people have been trying to show the brain midline structure through echocardiography (A-type) to discover the intracranial lesions. Because the advent of modern computer-aided imaging techniques (CT, MRI, etc.), the ultrasonography was not be used in clinic. However, with the development of ultrasound probes, the improvement of computer technology in ultrasound equipment and the appearance of the ultrasound signal enhancer in recent years, intravascular ultrasound diagnostic techniques attracted renewed attention. In 1990, transcranial color-coded sonography (TCCS) has been used in clinical as a new technology. It make the possibility of visualization of intracranial structures by ultrasonic with the capabilities of displaying transcranial color-coded frequency shift or the reflected energy image, combined with the B-mode ultrasound imaging and the function of pulse Doppler. TCCS was the further rational development of TCD technology, broadening the application of ultrasound. Therefore, TCCS became an new noninvasive method addition to the classic neuroimaging techniques, like CT, MRI and so on. It makes up the neuroimaging methods’ deficiencies that can’t be real-time imaging, continuous monitoring.The research discussed in two parts. First, analysis the relationship of the midline shift measured by head CT and the levels of consciousness, the occurrence of hernia between, the short-term outcomes in neurocritical patients with supratentorial cerebral infarction. Then we will discuss the importance and necessity of the monitoring of MLS. Second, explore the reliability and feasibility of monitoring midline shift by transcranial color-coded sonography in neurocritical patients and assess the clinical value in neurocritical patients.Subjects and methodsThere were two parts in this study.The first part, we analyzed the relationship of the midline shift measured by head CT and the levels of consciousness, the occurrence of hernia between, the short-term outcomes in neurocritical patients with supratentorial cerebral infarction.The study was carried out at the NICU of Nanfang hospital, Southern Medical University of China, from June 2010 to December 2014. Inclusion criteria included: 1) older than 18 years old; 2) accomplish head CT at least one time at the time of hospitalization; 3) patients with acute cerebral infarction confirmed by CT and (or) MRI; 4) did not used medications (sedative drugs, narcotic drugs, antipsychotics, etc.) what can significantly affect the level of patient’s consciousness within 24 hours before the head CT examination; 5) Before the admission, there is no serious heart disease, kidney disease, blood disease or malignancy. Exclusion criteria included:1) patients with acute posterior circulation, such as the brain stem, cerebellum lesions; 2) patients with bilateral cerebral hemispheres stoke; 3) the third ventricle did not been seen at the head CT scan that can’t measure the midline shift; 4) patients with decompressive craniectomy;5) the information is incomplete or lost to follow-up. Record the head CT examination’s time and the level of consciousness at the same time of all rolled patients. Assess the level of consciousness using the Glasgow Coma Scale (GCS).The following information was collected for all the patients:basic demographic data (age, gender), diagnosis, onset of disease.Head CT completed by the radiology department. In the horizontal cross-section of the third ventricle, draw a straight line from falx to the sagittal sinus. All patients will be incorporated into the midline structure centered group and midline shift group. The bilateral distance from the external side of the skull to the center of the third ventricle was measured(distance CTL and CTR), and the following mathematical formula was applied:MLS-CT=|(CTL-CTR)|/2. Then analyze the difference of conscious stander between the two groups and the relationship of the midline shift measured by head CT and the levels of consciousness.Patients were followed up at 30days after onset. The outcome for survivors was assessed using Modified Rankin Scores. According to the clinical symptoms and the head CT scan, the patients were divided into three groups:the hernia group, the borderline group and the control group. Analyze the outcomes of the three groups and the predictive value of MLS to the occurrence of hernia and death during 30 days. According to the completion of head CT, all date of MLS can be divided into 24 hours,24-48 houts,48-96 hours,4-7 days and 1-3 weeks, then analyzing the relationship of MLS and patients’outcomes at 30 days.SPSS 13.0 software was used for analysis. Means and standard deviations were calculated for measurement data. Differences between groups were assessed by the Wilcoxon test. The MLS of patients with different levels of consciousness were compared by the One-Way ANOVA. Prognosis of the three groups, the hernia group, the borderline group and the control group, were compared by χ2 test. The predictive value of MLS to the occurrence of hernia and death was assessed by receiver operating curve. Spearman correlation analysis was performed on the relationship between MLS of different time periods and mRS. P<0.05 was considered statistically significant.The second part, to explore the reliability and feasibility of monitoring midline shift by transcranial color-coded sonography(TCCS) in neurocritical patients and assess the clinical value in neurocritical patients.Patients admitted to the neurocritical care unit (NICU) from October 2013 to April 2013 were enrolled in this study. All patients were conducted the Computerized Tomography (CT) and the TCCS studies in a 3-hour time window. The following information was collected for all the patients:basic demographic data (age, gender), diagnosis, onset of disease. Record the time of head CT and TCCS examination and the data of two inspection method were collected by two different persons. All patients will be incorporated into the midline structure centered group and midline shift group. TCCS was completed by the application of GE vividi ultrasound,3R-RS 1.5～3.6MHZ probe.SPSS 13.0 software was used for analysis. Means and standard deviations were calculated for measurement data.The difference of the MLS measured by CT and TCCS was analyzed by paired T-test. The MLS measured by the two methods analyzed by scatter plot first, then analyzed by bivariate linear correlation. The same analysis was performed on the group of MLS<5 mm and the group of MLS≥5 mm. P<0.001 was considered statistically significant.ResultsIn the first part,104 patients were included, a total of 179 sets of data.The mean age was 68.75±13.30 years old(29-94 years old). The average GCS score is 10.02± 3.37, mRS score is 4.63±1.70.53 (50.96%) patients were survival and 51 (49.04%) patients were died.Analyzed by the Wilcoxon test, the levels of consciousness of the midline structure centered group and the midline shift group are significantly different (Z=-7.855, P<0.001). Drowsiness and coma accounted for 75.5% of the total. The MLS of patients with different levels of consciousness were compared by the One-Way ANOVA. The MLS of different levels of awareness have significant differences (P<0.001).The MLS of patients with coma is 6.51±5.67 mm,1.72± 1.45 mm with drowsiness and 4.05±4.03 mm with stupor.The outcomes of the hernia group, the borderline group and the control group are significantly different(χ2=20.464, P<0.001). The mortality of patients in hernia group reached 94.7% within 30 days. One-Way ANOVA analysis was used to compare the difference of the MLS in the three groups. Statistically significant was be found. The MLS of patients in hernia group is 10.62±4.47 mm, the borderline group is 4.14±2.92 mm and the control group is 1.10±1.17 mm. The predictive value of MLS to the occurrence of hernia assessed by receiver operating curve is significantly different. MLS of> or=5mm identified patients with a high probability of hernia with a specificity of 89.5% and a sensitivity of 93.9%.The outcomes at 30 days of the midline structure centered group and the midline shift group are significantly different analyzed by the Wilcoxon test(Z=-4.068, P<0.001). The mortality of patients in the midline structure centered group is 70.3% and the rate of poor prognosis is 91.9%. The predictive value of MLS to the death within 30 days assessed by receiver operating curve is significantly different. MLS of> or=4mm identified patients with a high probability of mortality with a specificity of 37.3% and a sensitivity of 90.6%.In the second part, The mean age of the 70 patients included was 68.75±13.30 years old (29-94 years old). The interval between head CT and TCCS examination was 83.94±43.36 minutes. The MLS measured by head CT and TCCS were 3.18± 2.52 mm and 3.10±2.57 mm. The difference of the two inspection methods was 0.07±0.59 mm,95% confidence interval was (-0.07,0.21) mm (P=0.32, n=70).38 patients were included in the midline structure centered group.The MLS measured by TCCS was -0.01±1.50 mm(95%CI=-0.49-0.50). The difference of the MLS measured by CT and TCCS was 0.21±0.71 mm, with no significant difference (P=0.31,n=38).The scatter plot showed that the MLS measured by CT and TCCS located on both sides of the same straight line and the correlation coefficient was 0.981. Similarly, the correlation coefficient of the he group of MLS<5 mm and the group of MLS>5 mm were 0.959 and 0.972.Conclusion1. MLS in patients with supratentorial cerebral infarction is closely related to the level of consciousness.2. The outcomes at 30days of supratentorial cerebral infarction patients in the midline structure centered group and the midline-shift-group have significant difference.3. MLS in patients with supratentorial cerebral infarction can predict the occurrence of brain hernia and the death within 30 days.4. MLS in patients with supratentorial cerebral infarction is an independent factor of prognosis, and positively correlated to the outcome at 30days, but the correlation coefficient is low.5. TCCS and head CT measurement of MLS correlated with coefficient of 0.981(P<0.001).It is a non invasive, quickly available, repeatable and reliable bedside technique that allows the monitoring of MLS. |
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