Neurophysiological Research Articles

The risk factors of neurological monitoring events in severe thoracic vertebral column resection cases

Objective To evaluate the effect of multimodality intraoperative neurophysiological monitoring (IONM) for severe thoracic posterior vertebral column resection (PVCR) surgery, and detail the risk factors of intraoperative monitoring events at various surgery procedures. Methods Monitoring data at various surgery procedures in 82 severe thoracic posterior vertebral column resection cases treated in our center between January 2010 and March 2015 were reviewed. This series of cases including 37 female and 45 male, the initial age averaged 22.6±9.6 years (range 8-66 years). All patients were followed up for minimum 1 year (average 40.7±18.2 months, range 12-74 months). The etiologies of spinal deformity were idiopathic in 36 cases, congenital in 20 patients, tuberculosis in 3 Patients, neurofibromatosis in 9 patients, and neuromuscular in 13 cases. The function of spinal cord and nerve root were assessed by SEP+MEP+ DNEP and tEMG+sEMG combined monitoring during operation, respectively. The monitoring outcomes and the risk factors of cord monitoring events were recorded and analyzed, and then prevention measures were suggested according to our clinical practice and literature review. Results In these cohort cases, combined monitoring of SEP+MEP+DNEP+tEMG+sEMG was successfully achieved in all 82 cases. On average, the major coronal curve was corrected from a preoperative 122.3°±27.6° to a postoperative 55.1°±21.5°, with a correction rate of 55.4%. The sagittal kyphosis was corrected from a preoperative 123.4°±27.8° to a postoperative 53.8°±19.7°, with a correction rate of 56.2%. The average resection vertebra was 1.33±0.6 levels with 11 meshes and 18 cages being planted into 29 patients. The average intra-operative blood loss and surgery time were 2911±1358 ml and 505±105 mins. There were 39 monitoring changes occurred in 27 cases out of 82 (32.9%). Results indicated that neurological monitoring events were more likely to occur in patients with larger scoliosis and kyphosis, longer closure distance of osteotomy, more Halo gravity traction, more screw insertion and higher PVCR segments. The reasons of monitoring changes included screw malposition (6/39), hypotension (2/39), osteotomy maneuver (5/39), cord concussion (4/39), bony compression (7/39), subluxation (4/39), styptic gauze compression (3/39), cord kniking (4/39), and over correction (4/39). After timely detection and intervention during operation, 11 of 82 cases presented new post-operative neural deficit, including 1 incomplete paralysis, 8 transient cord deficit and 2 nerve root injury. Conclusion IONM is effective to predict the spinal cord deficit at different surgery stages. Our report showed PVCR and PVCR site closure had a relatively high neurological risk, and operative manipulation was the main reason of monitoring events. Key words: Thoracic vertebrae; Spinal curvatures; Osteotomy; Evoked potentials, somatosensory; Evoked potentials, motor; Electromyography

Retrospective study of spine tumor surgery with intraoperative neurophysiological monitoring

Objective To summarize the application features of IONM in spine tumor surgery and evaluate its value. Methods From September 2012 to June 2015, a total of 119 patients who underwent spine tumor surgery with IONM at the Sun Yatsen Memorial Hospital were retrospectively analyzed. IONM includes somatosensory evoked potentials (SEP), transcranial-electrical stimulation motor evoked potentials (TcE-MEP) and spontaneous, triggered electromyography (EMG). There were 64 males and 55 females with an average age of 44.8 years (range 4-80 years). 59 cases were primary tumors (included 28 cases of neurogenic tumors) and 60 were spinal metastasis. We judged the IONM alarm of true, false positive and negative cases based on whether related to surgery and postoperative neurological function. The statistical indexes were calculated and analyzed. Results The operation time was 2-12 h with an average of 4.8 h and the blood loss was 50-7 000 ml with an average of 1 800 ml. All the patients were followed up for average of 12.6 months (range 4-36 months). IONM alarmed in 17 cases (included 11 cases of neurogenic tumors), in which 8 cases were true positive results including 3 cases directly related to revocable operative maneuvers and 5 cases with definitely spinal cord or peripheral nerve injury, 9 cases were false positive results without certain cause or nerve injury, other 102 cases were true negative results and there was no false negative case. The sensitivity was 100.0%, specificity was 91.9%, Youden index was 0.92, false positive rate was 9.1%, false negative rate was 0.0%, positive predictive value was 47.1%, and negative predictive value was 100.0%. Conclusion The application features of IONM in spine tumor surgery were many systematic changes resulted false positive cases and selectively nerve resection related several true positive cases. IONM can effectively monitor the spinal cord and peripheral nerves and predict the postoperative neurological function. It has high application value in spine tumor surgery. Key words: Spinal neoplasms; Evoked potentials, somatosensory; Evoked potentials, motor; Electromyography

The study and application of intraoperative neurophysiological monitoring in oblique lateral interbody fusion combined with posterior transpedicle internal fixation

Objective To investigate a reliable and practicable model of intraoperative neurophysiological monitoring (IONM) in oblique lateral interbody fusion (OLIF) combined with posterior transpedicle internal fixation. Methods A total of 34 consecutive patients who underwent OLIF combined with posterior transpedicle internal fixation with IONM at the SRRSH from November 2014 to July 2016 were collected and follow-up at least for 3 months postoperative. The intraoperative somatosensory evoked potentials (SEP), motor evoked potentials (MEP), dermatomal somatosensory evoked potential (DSEP) and spontaneous electromyography (sEMG) were used and evaluated, besides, triggered electromyography (tEMG) was used to monitor the implantation of pedicle screws, the possible reasons and treating procedures of monitoring alerts were summarized. Results A total of 34 cases of patients were effectively monitored during OLIF combined with posterior transpedicle internal fixation. SEP monitoring was successful in all patients, and no abnormal SEPs were observed in all cases. DSEP monitoring was successful in 20 cases (58.8%), and no abnormal DSEPs were observed in these patients. MEP was successfully monitored in all cases, eliminating the anesthesia factor, no abnormal MEPs were observed in all cases. The sensitivity and positive predictive value of SEP, MEP, DSEP were 0%. 3 cases had abnormal sEMG reactions during the channel establishment which disappeared after adjustment of channel, and 2 cases which appeared abnormal wave recovered after brief observation. Among the 5 patients with abnormal wave, one case got numbness, one patient felt pain in front of the thigh postoperative. Among the other 29 patients without abnormal wave during channel establishment, one case appeared numbness. These 3 patients with neurologic symptoms recovered in 3 months after conservative treatment. The sensitivity and specificity of sEMG was 66.7% and 90.3% respectively, negative predictive value and positive predictive value were 96.6% and 40% respectively. 6 screws got tEMG response after tapping even the intensity was less than 10mA, which showed broken codex of pedicle according to postoperative CT scan. Conclusion Intraoperative application of sEMG monitoring in OLIF can obviously reduce the incidence of the neurological deficit, which was an effective method. tEMG monitoring during lumbar pedicle screw fixation can detect the mal-positioned screws and protect the nerve roots. SEP, MEP and DSEP did not seem well suited for OLIF. Key words: Lumbar vertebrae; Spinal fusion; Evoked potentials, somatosensory; Evoked potentials, motor; Electromyography

Application of descending neurogenic evoked potentials monitoring during spinal deformity surgery

Objective To elevate the efficacy and safety of descending neurogenic evoked potentials (DNEP) monitoring during severe rigid spinal deformity surgery. Methods All of 108 patients (43 males, 65 females) who underwent surgical treatment for spinal deformity in our spinal center from July 2010 to August 2013 were retrospectively reviewed. The average age (17.5± 5.8) ys(range 12-50 ys), the average following period is 38.6 months(range 24-52 months). Combined monitoring of SEP, MEP and DNEP model were used during surgery. All subjects with no neurological deficits preoperatively and got satisfied outcomes. Respectively evaluate the results of neurophysiological intraoperative monitoring (IOM). Data were collected to elevate the efficacy and safety of DNEP monitoring. Results All of 108 patients, 15 patients (13.9%, 15/108) showed significant changes of neuro-physiological parameters, of which 9 cases (60%, 9/15) were identified as true positive and 6 cases (40%, 6/15) were identified as false positive. During the following-up period, 2 patients developed permanent neurological deficit, and 3 patients showed transient neurological deficit who got fully recovered within 6 months after operation. DNEP showed alert in all 5 patients with truepositive alarm, of which 2 patients developed permanent neurological dysfunction and 3 cases showed postoperative short nerve dysfunction that got fully recovery within 6 months after operation. The sensitivity and specificity of SEP+MEP and DNEP were 100% and 97.98%, 100% and 98.99%, respectively. Conclusion Combining use of MEP+SEP+DNEP monitoring during surgical treatment of spinal deformities presented to be a highly reliable method for the detection and prevention of iatrogenic injury. The results confirmed a high efficacy and safety of DNEP monitoring during spinal surgery. Key words: Spinal curvatures; Osteotomy; Evoked potentials, somatosensory; Evoked potentials, motor

Mechanisms of blood pressure salt sensitivity: new insights from mathematical modeling.

Mathematical modeling is an important tool for understanding quantitative relationships among components of complex physiological systems and for testing competing hypotheses. We used HumMod, a large physiological model, to test hypotheses of blood pressure (BP) salt sensitivity. Systemic hemodynamics, renal, and neurohormonal responses to chronic changes in salt intake were examined during normal renal function, fixed low or high plasma angiotensin II (ANG II) levels, bilateral renal artery stenosis, increased renal sympathetic nerve activity (RSNA), and decreased nephron numbers. Simulations were run for 4 wk at salt intakes ranging from 30 to 1,000 mmol/day. Reducing functional kidney mass or fixing ANG II increased salt sensitivity. Salt sensitivity, associated with inability of ANG II to respond to changes in salt intake, occurred with smaller changes in renal blood flow but greater changes in glomerular filtration rate, renal sodium reabsorption, and total peripheral resistance (TPR). However, clamping TPR at normal or high levels had no major effect on salt sensitivity. There were no clear relationships between BP salt sensitivity and renal vascular resistance or extracellular fluid volume. Our robust mathematical model of cardiovascular, renal, endocrine, and sympathetic nervous system physiology supports the hypothesis that specific types of kidney dysfunction, associated with impaired regulation of ANG II or increased tubular sodium reabsorption, contribute to BP salt sensitivity. However, increased preglomerular resistance, increased RSNA, or inability to decrease TPR does not appear to influence salt sensitivity. This model provides a platform for testing competing concepts of long-term BP control during changes in salt intake.

Research advances in susceptible genes for developmental dyslexia in children

Developmental dyslexia in children is one of the neurodevelopmental disorders and is affected by various susceptible genes. In recent years, researchers have found some susceptible genes for dyslexia via chromosome analysis, genome-wide association studies, association analysis, gene function research, neuroimaging, and neurophysiological techniques. This article reviews the research advances in susceptible genes for developmental dyslexia, and with the study on susceptible genes for dyslexia, it lays a foundation for in-depth studies on the "gene-brain-behavior" level and provides scientific clues for exploring etiology and pathogenesis of dyslexia.

Schwann cells: a new player in the tumor microenvironment.

Cancerous cells must cooperate with the surrounding stroma and non-malignant cells within the microenvironment to support the growth and invasion of the tumor. The nervous system is a component of every organ system of the body, and therefore, is invariably at the front line of the tumor invasion. Due to the complexity of the nervous system physiology, this review separately discusses the contributions of the central and peripheral nervous systems to the tumorigenesis and tumor progression. We further focus the discussion on the evidence that Schwann cells aid in tumor growth and invasion. Schwann cells, a largely unexplored element of the tumor microenvironment, may participate in the creation of tumor-favorable conditions through both bi-directional interaction with cancer cells and the facilitation of the immune-suppressive microenvironment through the mechanism of neural repair and immunomodulation.

Challenges of Finding Novel Drugs Targeting the K-Cl Cotransporter.

Human disease-causing mutations and genetically modified mouse models have established the importance of KCC2 and KCC3 in nervous system physiology. These two proteins mediate the electroneutral cotransport of K+ and Cl- ions across the neuronal membrane. Disruption of KCC2 function affects inhibitory synaptic transmission with consequences for epilepsy, pain perception, and potentially some neuropsychiatric disorders, whereas disruption of KCC3 affects both central and peripheral nervous systems, resulting in psychosis and peripheral neuropathy. Until recently, the KCC field has suffered from an almost complete lack of pharmacological tools with which to probe cotransporter function. The only available tools being the very poorly potent loop diuretics (e.g., furosemide EC50 = 6 × 10-4 M). To address this deficiency, efforts that focused on the discovery of KCC modulators have been undertaken. This work has resulted in the discovery of novel inhibitory compounds that are up to four orders of magnitude more potent (EC50 = 6 × 10-7 M) and with increased specificity. While useful for ex vivo studies, these tools possess poor pharmacokinetic properties, severely limiting their utility in vivo. In addition, only a few agents acting on regulatory molecules have been identified as putative KCC activators. Thus, further research is required to develop tools suitable to advance our understanding of how KCC modulation may be useful for the treatment of disease.

Suggestions for the Effective Intraoperative Neurophysiological Monitoring in Microvascular Decompression Surgery of Hemifacial Spasm

편측성 안면경련(hemifacial spasm)은 불수의적으로 안면의 근육에서 발작적인 경련이 일측성으로 반복해서 발생하는 질환이다. 한 근육의 수축으로 인해 동시적으로 여러 근육이 동시에 수축되는 동시 수축성(synkinesia)이 특징이다. 발병원인은 제 7뇌신경인 안면신경이 혈관에 의해 압박을 받아서 나타나게 된다. 본 연구는 편측성 안면경련 환자의 미세혈관 감압 수술을 받은 환자를 대상으로 수술 중 진행되는 신경계 감시검사 방법들에 대해 다루었다. 청각유발전위 검사에서는 수술용 뇌 견인기의 사용시 주의 사항과 검사시기에 대해 언급하였다. 안면신경의 근전도검사에서는 잡파의 혼입과 신경손상 시 근전도 파형의 감별에 대해, 측면전파반응 검사에서는 마취의 유지의 중요성에 대해 그리고 체성감각 유발전위검사에서는 환자를 좀더 자세하게 검사할 수 있도록 새로운방법을 제안하였다. 위에 언급한 내용들을 토대로 검사한다면 수술중 신경계 감시 검사를 원활하게 할 수 있으리라 생각된다.

Reliability and diagnostic validity for schizophrenia of the Japanese version of the Bonn Scale for Assessment of Basic Symptoms (BSABS).

Schizophrenia is defined by operative diagnostic criteria in DSM-IV with some typical symptoms as hallucinations and duration of the disease. Huber focused on the subjective experience of patients and coined the term "basic symptoms" and created BSABS. Our study investigated the reliability and the diagnostic validity of the 5 clusters of BSABS for DSM-IV-based diagnosis of schizophrenia with a cohort of 105 patients. Good inter-rater reliability was obtained except for one item D.10. As evaluated by Spearman's rank correlation coefficients, among the 5 clusters excluding Cluster 2, internal consistency was good. This suggests that, although each cluster is heterogeneous, cluster symptoms are the expression of physiological and biological disturbances of schizophrenia. Receiver Operating Characteristic Curve analysis was also used to show the ability of each cluster to discriminate schizophrenia. Results showed that the area representing the powers in discriminate schizophrenia of Cluster 4 "Adynamia", which is considered related to the dynamic aspect of thinking, was highest, at 0.739. Cluster 1 "Information processing disturbances" which has a predictive ability for schizophrenia showed 0.714 and Cluster 3 "Impaired tolerance to normal stress" showed 0.711. Our findings suggest that, although these clusters symptoms differ from DSM-IV criteria, they are related to fundamental process of schizophrenia. Use of some of these three clusters with other neurophysiological markers could allow clinical evaluation of schizophrenia from a new perspective.

Levodopa enhances immobility induced by spinal cord electromagnetic stimulation in rats

BackgroundThe repetitive ElectroMagnetic Stimulation (rEMS) is an innocuous method applied to modulate neurocircuits in real-time to study the physiology of the central nervous system and treat neuropsychiatric conditions. Preliminary data suggest that spinal rEMS induces behavioral changes in awake rats. However, the mechanisms behind this phenomenon remain largely unknown. MethodsTwenty-five male Wistar rats were divided into five subgroups of five animals each: one subgroup was drug-free, two subgroups received Levodopa+Benserazide 250+25mg/kg for two or seven days, and the remaining two subgroups received Haloperidol 0.1 or 0.3mg/kg for two days. The animals were restrained during sham rEMS (day 1) followed by real rEMS of the cervicothoracic region at a different day (day 2 or 7, depending on subgroup). Four behavioral parameters were quantified: Walking, Climbing, Grooming, and Cornering. ResultsrEMS reduced Walking and increased Cornering duration when applied over the cervicothoracic region of drug-free animals. A pretreatment with Levodopa+Benserazide for two or seven days induced an additional decrease in Walking after rEMS. This reduction was maximum after the treatment for seven days and associated with extinction of Climbing and increase in Cornering. A pretreatment with Haloperidol 0.1mg/kg reduced Grooming after rEMS, but did not prevent the reduction in Walking. ConclusionsCervicothoracic rEMS induced complex immobility responses that are in part modulated by dopaminergic pathways in rats. Further studies are necessary to determine the specific mechanisms involved.

Affective touch awareness in mental health and disease relates to autistic traits - An explorative neurophysiological investigation.

Affective touch is important for social interaction within families and groups and there is evidence that unmyelinated C tactile fibers are involved in this process. Individuals with autism spectrum disorders show alterations in the perception and processing of affective touch. sThus, we hypothesized that affective touch awareness based on C tactile fiber activation is impaired in individuals with high levels of autistic trait. The pleasantness perception of optimal and suboptimal C tactile stimuli was tested in an explorative study in 70 patients recruited from an outpatient psychotherapy clinic and 69 healthy comparison subjects. All participants completed questionnaires about autistic traits, depressive symptomatology, childhood maltreatment, and about the daily amount of touch. Relative to comparison subjects, patients reported engaging in touch less frequently in daily life and rated touch less pleasant. Reduced valence ratings of touch were explained by childhood maltreatment but not by any particular disorder or depression severity. Among all tested variables, the affective touch awareness correlated with autistic traits only - in patients as well as in comparison subjects. Taken together, individuals with mental health issues have a lower baseline of expression and reception of affective touch. Autistic traits and childhood maltreatment modulate the experience of affective touch.

Potential Contribution of Antioxidant Mechanism in the Defensive Effect of Lycopene Against Partial Sciatic Nerve Ligation Induced Behavioral, Biochemical and Histopathological Modification in Wistar Rats.

Neuropathic pain is a severe and unbearable condition which arises due to activation of peripheral nociceptors after tissue damage, neuropathic pain is caused from anomalous physiology of central or peripheral nervous system and it may not be related to the ongoing tissue damage or inflammation. Involvement of oxidative damage has been reported in the pathophysiology of neuropathic pain. The purpose of this study was to examine the effect of lycopene to quench the free radicals produced as a result of the increased oxidative stress in neuropathic pain. Neuropathic pain was induced in wistar rats by partial sciatic nerve ligation. The effect was evaluated by assessing various behavioral parameters (thermal hyperalgesia, cold hyperalgesia), biochemical parameters (lipid peroxidation, reduced glutathione, superoxide dismutase and catalase) as well as histopathological parameters in sciatic nerve. During the experiment group of 8 rats each was administered drugs once daily intraperitonealy (I.P.) and naïve groups, sham group and sciatic nerve ligated group were treated with vehicle for the duration of 14 days. Partial sciatic nerve ligation (PSNL) significantly caused thermal hyperalgesia, cold hyperalgesia and oxidative damage compared to normal and sham groups. Daily administration of lycopene (25 mg/kg, 50 mg/kg) and gabapentin (100 mg/kg) considerably reversed hyperalgesia, cold hyperalgesia and attenuated oxidative stress when compared to control group. There was significant histological improvement in the in the architecture of myelinated and unmyelinated fibers. The results indicated that free radical generation mechanism might be involved in PSNL induced behavior, biochemical and histopathological changes in wistar rats.

Are astrocytes executive cells within the central nervous system?

Experimental evidence suggests that astrocytes play a crucial role in the physiology of the central nervous system (CNS) by modulating synaptic activity and plasticity. Based on what is currently known we postulate that astrocytes are fundamental, along with neurons, for the information processing that takes place within the CNS. On the other hand, experimental findings and human observations signal that some of the primary degenerative diseases of the CNS, like frontotemporal dementia, Parkinson's disease, Alzheimer's dementia, Huntington's dementia, primary cerebellar ataxias and amyotrophic lateral sclerosis, all of which affect the human species exclusively, may be due to astroglial dysfunction. This hypothesis is supported by observations that demonstrated that the killing of neurons by non-neural cells plays a major role in the pathogenesis of those diseases, at both their onset and their progression. Furthermore, recent findings suggest that astrocytes might be involved in the pathogenesis of some psychiatric disorders as well.

Metalloneurochemistry and the Pierian Spring: 'Shallow Draughts Intoxicate the Brain'.

Metal ions perform critical and diverse functions in nervous system physiology and pathology. The field of metalloneurochemistry aims to understand the mechanistic bases for these varied roles at the molecular level. Here, we review several areas of research that illustrate progress toward achieving this ambitious goal and identify key challenges for the future. We examine the use of lithium as a mood stabilizer, the roles of mobile zinc and copper in the synapse, the interplay of nitric oxide and metals in retrograde signaling, and the regulation of iron homeostasis in the brain. These topics were chosen to demonstrate not only the breadth of the field, but also to highlight opportunities for discovery by studying such complex systems in greater detail. We are beginning to uncover the principles by which receptors and transmitters utilize metal ions to modulate neurotransmission. These advances have revealed exciting new insights into the intricate mechanisms that give rise to learning, memory, and sensory perception, while opening many new avenues for further exploration.

Overview of the Anatomy, Physiology, and Pharmacology of the Autonomic Nervous System.

Comprised of the sympathetic nervous system, parasympathetic nervous system, and enteric nervous system, the autonomic nervous system (ANS) provides the neural control of all parts of the body except for skeletal muscles. The ANS has the major responsibility to ensure that the physiological integrity of cells, tissues, and organs throughout the entire body is maintained (homeostasis) in the face of perturbations exerted by both the external and internal environments. Many commonly prescribed drugs, over-the-counter drugs, toxins, and toxicants function by altering transmission within the ANS. Autonomic dysfunction is a signature of many neurological diseases or disorders. Despite the physiological relevance of the ANS, most neuroscience textbooks offer very limited coverage of this portion of the nervous system. This review article provides both historical and current information about the anatomy, physiology, and pharmacology of the sympathetic and parasympathetic divisions of the ANS. The ultimate aim is for this article to be a valuable resource for those interested in learning the basics of these two components of the ANS and to appreciate its importance in both health and disease. Other resources should be consulted for a thorough understanding of the third division of the ANS, the enteric nervous system. © 2016 American Physiological Society. Compr Physiol 6:1239-1278, 2016.

Elio Lugaresi, MD (1926–2015)

Prof. Elio Lugaresi died on December 22, 2015, at age 89. His legacy was substantial. Elio Lugaresi's career was devoted to the study of neurology, neurophysiology, epilepsy, and primarily to sleep, a passion he pursued well into retirement.

Correlations of neurophysiological features with clinical manifestation in patients with diabetic peripheral neuropathy

Objective To explore the correlation of electrophysiological features with clinical manifestation in patients with diabetic peripheral neuropathy(DPN). Methods The clinical data of 306 patients with DPN undergoing nerve conduction study (NCS) during May 2013 to June 2015 were retrospectively analyzed. Among 306 patients, 304 were type 2, and 2 were type 1 diabetes with a mean age of 64.1 years and disease duration of 1 week-31 years. The relationship between the electrophysiological features and clinical manifestations was evaluated. Nerve conduction studies and F-wave and in sympathetic skin response were analyzed. Results ① NCS in lower limbs presented more abnormalities than that in upper limbs. There was the highest prevalence of not elicited sensory potential in Tibial nerve [56.9%(174/306), χ2=175.9] and the highest prevalence of not elicited motor potential in peroneal nerve [7.8%(24/306), χ2=1 103.1]. Amplitude abnormality was more severe in sensory nerve than that in motor nerve [41.4%(507/1 224) vs. 10.8%(132/1 224), χ2=559.2]. The ratio of abnormal motor conduction velocity or distal latency was higher than that of amplitude decreased [22.9%(280/1 224) vs. 10.8%(132/1 224), χ2=1 077.4]. ② The abnormal ratios of the shortest F-wave latency was lower than that of the prolonged distal latency in median and tibial nerve [5.4%(33/612) vs. 20.6%(126/612), χ2=607.6]. ③ The abnormal ratio of sympathetic skin response (SSR) in lower limbs were higher than that of upper limbs [40.2%(246/612)vs. 27.3%(167/612), χ2=129.4, P<0.001], abnormal ratio of amplitude was higher than that of the prolonged latency [30.1%(368/1 224) vs. 4.7%(58/1224), χ2=1 040.5, P<0.001]. Among the 99 cases presenting abnormal SSR in upper limbs, 32 cases were normal in conventional NCS. Among the 127 cases presenting abnormal SSR in lower limbs, 7 cases were normal in conventional NCS. ④Disease course and glycosylated hemoglobin values were positively correlated with the distal motor latency, and negatively correlated with the nerve conduction velocity and amplitude. Conclusion Electrophysiological features of DPN is mainly shown in axon of the distal sensory nerve. Long duration and hyperglycemia may lead to more abnormalities in electrophysiological tests. Key words: Diabetic neuropathies; Peripheral nerves; Neural conduction studies; Electrophysiology

Relationship between astrocytes and consciousness formation

Astrocytes were traditionally be deemed as supportive cells in the central nervous system.However, recent researches proved astrocytes exerted more important neurophysiological functions, such as regulation of synaptic transmission and integration of neural information.This paper summarized the researches on the functions of astrocytes related to synaptic transmission and analyzed the new features of astrocyte excitability, the communication between neurons and astrocytes and the effect of general anesthetics on astrocytes.Based on these new findings, this paper also suggested the underlying relationship between astrocytes and the loss of consciousness during general anesthesia. Key words: Astrocytes; Consciousness; Synaptic transmission; Anesthesia, general

The Cajal School in the Peripheral Nervous System: The Transcendent Contributions of Fernando de Castro on the Microscopic Structure of Sensory and Autonomic Motor Ganglia.

The fine structure of the autonomic nervous system was largely unknown at the beginning of the second decade of the 20th century. Although relatively anatomists and histologists had studied the subject, even the assays by the great Russian histologist Alexander Dogiel and the Spanish Nobel Prize laureate, Santiago Ramón y Cajal, were incomplete. In a time which witnessed fundamental discoveries by Langley, Loewi and Dale on the physiology of the autonomic nervous system, both reputed researchers entrusted one of their outstanding disciples to the challenge to further investigate autonomic structures: the Russian B.I. Lawrentjew and the Spanish Fernando de Castro developed new technical approaches with spectacular results. In the mid of the 1920’s, both young neuroscientists were worldwide recognized as the top experts in the field. In the present work we describe the main discoveries by Fernando de Castro in those years regarding the structure of sympathetic and sensory ganglia, the organization of the synaptic contacts in these ganglia, and the nature of their innervation, later materialized in their respective chapters, personally invited by the editor, in Wilder Penfield’s famous textbook on Neurology and the Nervous System. Most of these discoveries remain fully alive today.