The Forensic Study About The Value Of The SEP In Brain Injury

Brain injury is common in the identification of clinical forensic medicine. For their benefit, people under going identification sometimes tend to pretend to be disable or exaggerate the degrees of the functional disturbance, which make the subjective clinical examination more unbelievable. As a means of objective examination, imaging studies only provide the morphological changes. Because the variations of the adapt and compensation of human body are greater, there may be structural changes,but not abnormal in the function. Thereforce, it is important to find an objective way in determining the function of the brain injuried in clinical forensic medicine.In recent years,Somatosensory Evoked Potential (SEP) provided new means for the development of an objective solution to this issue. SEP reflected the function of the brain from the electrophysiology perspective. Since 1960s, studies about the evaluation on the Postherpetic function of Brain injury with SEP have been begun at abroad. There have been few clinical reports and no any reports in forensic medicine at internal since 1990s. SEP currently in the clinical application of brain injury more is Acute Phase about the forecastfor prognosis and rehabilitation period of ADL assessment, and the dysfunction of brain injury in the aftermath of less SEP, if the extent of abnormal SEP is associated with the extentof Postherpetic dysfunction after brain injury still in dispute. To that, In this paper, 21 cases of limb paralysis after brain injury patients and 17 patients with brain injury have no limb paralysis of the brain injury syndrome patients conducted SEP inspections, And 20 cases of normal controls,inorde to find the objective,dependable index, further explore the sequelae of brain injury SEP changes, and left with the function of the back of their minds, and provide the clinical forensic medicine with objective evidence.Subjects and methods1. Subjects Test group 1: 21 cases of paralysis after traumatic brain injury patients. By CT or MRI diagnosed with brain injury or pressure, the Manual Muscle Test was confirmed with unilateral paralysis of the upper limb, and with varying degrees of sensory dysfunction. Test group2:17 cases of traumatic brain injury syndrome patients,by CT or MRI diagnosed with brain injury or pressure, the Manual muscle test of strength are confirmed limbs grade V. Control group:20 cases of healthy volunteers.2.Methods(1) Apparatus Parameter settings and inspection methods:By NDI 200~+ electric nerve machine. An air-conditioned room at room temperature about 22℃. Shaoan light. All records are abtained with the subjects lying supine in a quiet room and relax. Median nerve SEP upper electrode lead: (1)Cc'-FPz (2)Cv7-FPz. Stimulating electrode silver chloride electrode for discoid, The electrode impedance is kept under 5Kohm.The nerve is stimulated using constant current square wave pulses of 0.1ms duration delivered at a frequency of 5Hz.the system bandpass is10-2000Hz. Analysis of time 50 ms, the intensity of stimulation can cause thenar muscle contraction prevail. Duplicate records for at least 2 times Were measured around.(2) Observed index:N13,P15,N20,P25,N35,P45 The waveform, peak latency(PL), Interside latency difference(ILD); N13-N20 Interpeak latency and ILD. Abnormal standard:(1)N13,P15,N20,P25,N35,P45 The wave disappeared or poorly differentiated. (2) More than the upper limit of peak latency of N13,P15,N20,P25,N35,P45 or the IPL of N13-N20 from the control by calculating the means plus 2.5 standard deviations. Abnormality will be determined on accordance of one of them.Experimental results1. 20 normal control group N13, P15, N20, P25, N35 are all normal, three cases (72.73%) P45 no leads.2. 21 cases of brain injury after only three cases of paralysis Group (14.29%) SEP normal, SEP abnomaly mainly to the cortex of the PL-extended wave disappeared or poorly differentiated. Grading and strength P15, N20, P25 of the PL, N13-20 of the IPL significantly negative correlation (P<0.001). 3. 17 cases of traumatic brain injury syndrome patients after brain injury SEP abnormal only six cases (35.29%), mainly for the extension of P15 or N20 PL (11.76 %).4. Traumatic brain injury syndrome patients, paralysis after traumatic brain injury patients and the normal control group, SEP have statistical difference among different classification ;strength SEP abnormal rate of significant differences in the statistical significance (x~2=11.939, P<0.05). The brain damage more severe degree of dysfunction, the more obvious changes in the SEP. The subjects of N35 PL it was no significant difference on the three groups(P> 0.05).Conclusion1,The peak latency of N13,P15,N20,P25 and IPLof N13-N20 of SEP are much more objective, dependable index in evaluation after brain injury left dysfunction degree. Among them IPL N13-N20 Can be excluded from the height and long limbs caused by individual differences. The abnormality rate can be increased by several index observed.2,P15 is the evaluation of brain function is a sensitive and objective indicators electrophysiology.3,Brain injury and the extent of dysfunction in the aftermath SEP anomaly is related to the degree, that is, the more severe the disease,the more severe the degree of abnormal SEP.4,SEP, as objective non-invasive electrophysiological methods, which supplement the information about nerve root function that can not be provided by imaging examination. It is helpful to determine the nerve function caused by brain injury in the identification of clinical forensic medicine. Help him make a judgement after brain injury level of dysfunction.