A 36-year-old man was brought unconscious to the emergency room; he suffered anoxic brain damage due to carbon monoxide (CO) intoxication, and had decerebrate rigidity clinically and died 1 month later after the acute insult. Computed tomography with contrast enhancement failed to show a brainstem lesion but the brainstem auditory evoked potential (BAEP) demonstrated the brainstem involvement. The BAEP can be used as an objective diagnostic aid for evaluating brainstem lesions in CO intoxication.
Adult ; Brain Stem/physiopathology* ; Carbon Monoxide Poisoning/physiopathology* ; Evoked Potentials, Auditory* ; Human ; Male

OBJECTIVETo study the effect of selective moderate head cooling therapy on maximum length sequences brainstem auditory evoked potential (MLS-BAEP) in newborn piglets with hypoxic-ischemic brain damage.

METHODSSixteen newborn piglets aged 5-7 day old were randomly divided into three groups: normothermic control (n=4), HI (n=6) and mild hypothermia-treated (n=6). HI was induced through temporary occlusion of both carotid arteries, followed by mechanical ventilation with low concentration of oxygen (FiO2=0.06) for 30 minutes. Mild hypothermia was induced by equipment via circulating water. MLS-BAER was recorded before HI and at 12 hours, 24 hours, 36 hours, 48 hours, 60 hours, 72 hours, 4 days, 7 days, 10 days, 13 days and 15 days after HI.

RESULTSCompared with the normothermic control group, all latencies and intervals tended to increase significantly at 72 hours in the HI group and reached peak values on day 7. From day 10, all latencies and intervals tended to decrease, but apart from wave I latency, still differed significantly from those of the normothermic control group. MLS-BAER variables did not reach normal values until day 15. Ⅲ latency, Ⅰ-Ⅲ interval and Ⅰ-Ⅴ interval were significantly reduced in the hypothermia-treated group between 60 and 7 days after HI compared with the HI group (P<0.05). V latency and Ⅲ-Ⅴ interval in the hypothermia-treated group were also reduced compared with the HI group between 72 hours and 7 days after HI (P<0.05).

CONCLUSIONSBoth peripheral and central auditory systems are disturbed by HI, which shows as a significant increase in MLS-BAER variables (all latencies and intervals) in newborn piglets. Involvement in central brainstem auditory system reaches a peak on day 7 after injury. MLS-BAER variables still cannot reach to normal values until day 15. Selective moderate head cooling therapy can significantly reduce brainstem damage induced by HI.

Animals ; Animals, Newborn ; Evoked Potentials, Auditory, Brain Stem ; Hypothermia, Induced ; Hypoxia, Brain ; physiopathology ; therapy ; Swine

OBJECTIVETo study the value of a new technique, maximum length sequences brainstem auditory evoked potential (MLS BAEP), in the assessment of the severity of brain damage following asphyxia in term neonates.

METHODSOne hundred and three neonates with perinatal asphyxia and 26 normal term neonates were eligible for the study. Conventional and MLS BAEP examinations were performed within three days after birth. Of the 103 neonates with asphyxia, 17 did not suffer from HIE, 37 had mild HIE, 31 had moderate HIE, and 18 had severe HIE. The latencies and amplitudes of waves I, III and V, and the inter-peak intervals of I-III, III-V, and I-V were analyzed.

RESULTSThe latencies of wave V and the inter-peak intervals of I-III, III-V and I-V prolonged gradually with the more severe HIE in both the MLS and the conventional BAEP (P<0.05 or 0.01). The differences among groups were more significant with the increasing repetition rate of click in the MLS BAEP. Compared with the normal controls, conventional BAEP did not show prolonged intervals of I-III and III-V in the mild HIE subgroup, and a prolonged inter-peak interval of III-V in the moderate HIE subgroup, while the MLS BAEP showed significantly prolonged inter-peak intervals of I-III and III-V in the three HIE subgroups and the differences were more and more significant as an increase in the repetition rate of click from 91 to 910 times/seconds.

CONCLUSIONSMLS BAEP is more sensitive and valuable than the conventional one in detecting hypoxic-ischemic brain damage following asphyxia by increasing the repetition rate of click. MLS BAEP provides a new measurement in quantity to assess the severity of HIE in neonates with perinatal asphyxia.

Asphyxia Neonatorum ; physiopathology ; Evoked Potentials, Auditory, Brain Stem ; Female ; Humans ; Hypoxia, Brain ; diagnosis ; Infant, Newborn ; Male

Traumatic brain injury (TBI) is a major cause of mortality and morbidity in the world. Recent clinical investigations and basic researches suggest that strategies to improve angiogenesis following TBI may provide promising opportunities to improve clinical outcomes and brain functional recovery. More and more evidences show that circulating endothelial progenitor cells (EPCs), which have been identified in the peripheral blood, may play an important role in the pathologic and physiological angiogenesis in adults. Moreover, impressive data demonstrate that EPCs are mobilized from bone marrow to blood circulation in response to traumatic or inflammatory stimulations. In this review, we discussed the role of EPCs in the repair of brain injury and the possible therapeutic implication for functional recovery of TBI in the future.
Blood-Brain Barrier ; Brain Injuries ; physiopathology ; therapy ; Endothelial Cells ; cytology ; Humans ; Neurogenesis ; Stem Cells ; physiology

OBJECTIVETo probe the changes of fast component of brainstem auditory evoked potentials (FC-BAEP), slow component of brainstem auditory evoked potentials (SC-BAEP) and the mitochondrial ultrastructures of the neurons in the brainstem in the rat pups with hyperbilirubinemia.

METHODS7 days old SD rat pups were randomly divided into control group (C, 17 rat pups) and two test groups (T1, 17 rat pups and T2, 17 rat pups). Bilirubin solutions (2 g/L) were injected into the abdominal cavity of the rat pups in the group T1 and T2 at the postnatal day 7 and 10. Six hours after the second injection, seven rat pups of each group were randomly selected to test serum bilirubin concentration via a micro-gauge. FC-BAEP and SC-BAEP were examined with an evoked potential recorder in the rest rat pups of each group at postnatal day 17 and 20. At the postnatal day 20, the endocardial perfusion was performed in these rat pups for the fixation of the brain, and then the brains were taken out. The cochlear nuclei were used for observation via electron microscope.

RESULTSSix hours after the injection of bilirubin solution at the postnatal day 10, the serum bilirubin concentrations of the rat pups in group T1 and T2 were increased significantly. Except for II-IV inter-peak latency(IPL), all the peak latency(PL) and IPL of FC-BAEP evoked via three sound stimulating rates (10/s, 40/s,80/s) at the postnatal day 17 prolonged significantly in the rat pups of group T1 and T2, and the PL in group T2 were much longer than that in group T1. Except for II-IV IPL of FC-BAEP evoked via sound stimulating rates of 10/s and 40/s, all the PL and IPL at the postnatal day 20 prolonged significantly in the rat pups of group T1 and T2. The PL of SC-BAEP evoked via sound stimulating rate of 10/s at the postnatal day 17 and 20 in the rat pups of group T1 and T2 prolonged significantly, and the PL at the postnatal day 17 in group T2 were much longer than that of group T1. The changes of mitochondria of the neurons in the cochlear nuclei at the postnatal day 20 in the rat pups of group T1 and T2 were characterized by swell, the slurred membranes, the broken crista and so on.

CONCLUSIONThere were the abnormal changes of FC-BAEP, SC-BAEP and the mitochondrial ultrastructures of the neurons in the brainstem in the rat pups with hyperbilirubinemia. The PL and IPL of FC-BAEP and SC-BAEP could be taken as the objective and sensitive indexes for early monitoring the bilirubin-induced hearing loss and brain injury.

Animals ; Animals, Newborn ; Brain Stem ; pathology ; Evoked Potentials, Auditory, Brain Stem ; physiology ; Hearing Loss ; etiology ; physiopathology ; Hyperbilirubinemia ; complications ; physiopathology ; Male ; Mitochondria ; ultrastructure ; Neurons ; ultrastructure ; Rats ; Rats, Sprague-Dawley

OBJECTIVE: To investigate the dynamic experiences of pathological changes in brain and the injured role of brainstem auditory evoked potential (BAEP) after closed Mild Traumatic Brain Injury (MTBI) in rat. METHODS: A closed diffuse brain injury model was successfully produced in rat by hit the parietal bone with a spring-droved steel stick. The auditory brainstem response evoked by click at 50Hz stimulating frequency were recorded at pre-trauma, 15 min and 1, 3, 6, 12 h and 1, 2, 4, 7, 10, 14, 21 d after brain injury. The pathological changes of brain were observed under light microscope and the brain edema was detected by wet weight/dry weight rations. RESULTS: The I-V, III-V of BAEP wave inter peak latency (IPL) in MTBI group increased immediately in 15 minutes after injury. The III, V wave peak latency (PL) and I-V, III-V wave IPL became longer than the pre-trauma level in 6, 12 h post-injury (P<0.05). The III, V wave PL and I - III, I - V, III - V wave IPL became longer than the pre-trauma level in 1, 2 d after injury (P < 0.001), the BAEP retuned to normal level in 14 d after brain injury. At 15 minutes after injury, the water content in brain increased and met its peak in 1 d, decreased gradually in 4 d, then decreased slowly and returned to normal level in 10 d after injury. CONCLUSION The regular changes of BAEP could be an objective tool for evaluating hearing dysfunction after closed mild diffuse traumatic brain injury.
Animals ; Auditory Perceptual Disorders/etiology* ; Brain/pathology* ; Brain Edema/pathology* ; Brain Injuries/physiopathology* ; Brain Stem/physiopathology* ; Disease Models, Animal ; Evoked Potentials, Auditory, Brain Stem/physiology* ; Male ; Random Allocation ; Rats ; Rats, Sprague-Dawley

Age Factors ; Animals ; Animals, Newborn ; Blood-Brain Barrier ; Brain ; blood supply ; physiopathology ; Brain Ischemia ; physiopathology ; therapy ; Models, Animal ; Rats ; Stem Cell Transplantation

OBJECTIVETo explore the effects of electrical stimulation at acupoints in the distribution area of auricular vagus nerve combined with sound masking on auditory brainstem response (ABR) and contents of neurotransmitters of γ-aminobutyric acid (γ-GABA), 5-hydroxytryptamine (5-HT) and acetyl choline (Ach) in inferior colliculus of tinnitus rats.

METHODSTwenty-four male adult SD rats were randomized into a control group, a model group, a 7-d treatment group and a 15-d treatment group. Except the control group, rats in the remaining groups were treated with intraperitoneal injection of 10% salicylate sodium at a dose of 350 mg/kg to establish tinnitus model. Rats in the control group were treated with injection of 0.9% NaCl. Rats in the 7-d treatment group and 15-d treatment group were treated with electrical stimulation at "Shenmen (TF₄)" and "Yidan (CO₁₁)" in the distribution area of auricular vagus nerve combined with sound masking, once a day, for 7 days and 15 days. The SigGenRP software of TDT system was applied to provide voice for single ear and collect the signal, and the voice threshold of ABR was tested. The levels of γ-GABA, 5-HT and Ach in inferior colliculus of rats were detected by enzyme linked immunosorbent assay (ELISA) and compared.

RESULTSCompared with the model group, the threshold values of ABR in 12 kHz and 16 kHz voice stimulation in the 7-d treatment group were significantly lower all P < 0.05); the threshold values of ABR from 4 kHz to 28 kHz voice stimulation in the 15-d treatment group were signally reduced (P < 0.05, P < 0.01), which was more significant than those in the 7-d treatment group. The level of γ-GABA in the model group was significantly lower than that in the control group (P < 0.05), and that in the 15-d treatment group was apparently higher than that in the model group (P < 0.05). The level of 5-HT in the model group was markedly higher than that in the control group (P < 0.05), and that in the 7-d treatment group was lower than that in the model group (P < 0.05), while that in the 15-d treatment group was apparently higher than that in the model group (P < 0.05). The level of Ach in the model group was obviously; lower than that in the control group (P < 0.05), and that in the 7-d treatment group was higher than that in the model group (P < 0.05).

CONCLUSIONElectrical stimulation at auricular vagus nerve combined with sound masking) could regulate the threshold of ABR, especially in the 15-d treatment group. This may be ascribed to modulating the levels of neurotransmitter of γ-GABA, 5-HT and Ach in inferior colliculus.

Acupuncture Points ; Animals ; Brain Stem ; physiopathology ; Electric Stimulation ; Evoked Potentials, Auditory, Brain Stem ; Humans ; Inferior Colliculi ; physiopathology ; Male ; Neurotransmitter Agents ; metabolism ; Rats ; Rats, Sprague-Dawley ; Serotonin ; metabolism ; Tinnitus ; physiopathology ; therapy ; Vagus Nerve ; physiopathology ; gamma-Aminobutyric Acid ; metabolism

OBJECTIVETo observe the injury of plumbism to the nerve system in children.

METHODSOne hundred children with plumbism which had no masculine body sign of nerve system were divided into two groups. Fifty of them were as controls, while others were treated by calcium. Fifty age and gender matched healthy children were selected as the normal group in order to compare with plumbism group. All of their auditory brainstem response (ABR), pure tone and distortion product otoacoustic emission (DPOAE) were examined.

RESULTSLatency period of wave V of the plumbism groups was longer than that of normal group. The difference between them was significant statistically (t =3.21, P <0.01). The interval between wave I and wave III of plumbism group was longer than that of normal group, but there was no difference between them (former: t = 2.06, P > 0.05; later: t = 1.64, P > 0.05). The interval between wave III and wave V and the interval between wave I and wave V of plumbism group was longer than that of normal group, and their difference was significant statistically (former: t = 7.30, P <0.01; later: t = 3.14, P < 0.01). The interval between wave I and wave III of plumbism group was longer than that of normal group, but there was no difference between them (t = 0.91, P > 0.05). The amplitude of wave I, wave III and wave V of plumbism group was lower than that of normal group, and their difference was significant statistically (I: t =3.20, P < 0.01; III: t=3.31, P < 0.01; V: t=3.41, P < 0.01). The auditory brainstem response, pure tone and DPOAE in all three groups had no obvious change after six months treatment (P >0.05).

CONCLUSIONSPlumbism may have potential clinical injury to nerve system. There has no obvious change of ABR after treatment by calcium. ABR may be a forepart examination to find the injury of plumbism to the nerve system.

Case-Control Studies ; Child ; Evoked Potentials, Auditory, Brain Stem ; drug effects ; Humans ; Lead Poisoning ; physiopathology

OBJECTIVETo investigate the relationship of bilirubin/albumin (B/A) ratio and acidosis with abnormal brainstem auditory evoked potentials (BAEPs) in neonates with severe hyperbilirubinemia and its clinical significance.

METHODSA total of 967 neonates with severe hyperbilirubinemia between November 2008 and October 2009 were enrolled in the study. They were divided into two groups according to their BAEPs: normal BAEP group (n=799) and abnormal BAEP group (n=168). Univariate analysis and age-stratified Chi-square test were used to determine the relationship of B/A ratio and acidosis with BAEP.

RESULTSThe univariate analysis showed that the abnormal BAEP group had significantly lower pH and base excess values and a significantly higher B/A ratio compared with the normal BAEP group (P<0.05). The age-stratified Chi-square test showed that neonates with acidosis or with a B/A ratio greater than 1.0 had a significantly higher incidence of abnormal BAEPs than those without acidosis or with a B/A ratio less than 1.0 in any age (days) group of neonates with severe hyperbilirubinemia (P<0.05).

CONCLUSIONSHigh B/A ratio and acidosis are the risk factors for abnormal BAEPs in neonates with severe hyperbilirubinemia, which is the case for those in any age group. In order to reduce the incidence of hearing loss in any age group of neonates with severe hyperbilirubinemia, we should correct the acidosis and lower the B/A ratio as soon as possible.

Acidosis ; physiopathology ; Bilirubin ; blood ; Evoked Potentials, Auditory, Brain Stem ; Humans ; Hyperbilirubinemia ; blood ; physiopathology ; Infant, Newborn ; Serum Albumin ; analysis