Neuroelectrophysiological indexes and clinical characteristics of patients with peroneal muscular atrophy: Retrospective analysis of 24 cases

BACKGROUND: Peroneal muscular atrophy (PMA) is characterized by insidious onset, gradually progressive course of disease, very mild disability degree and easily subjecting to missed diagnosis and misdiagnosis. Nerve conductive velocity is helpful in the diagnosis of atypical cases. OBJECTIVE: To retrospectively analyze the characteristics of clinical manifestation, electromyogram (EMG), motor and sensory nerve conduction velocity of patients with PMA. DESIGN: Retrospective case analysis. SETTING: Department of Neurology, Guangzhou First People's Hospital. PARTICIPANTS: Twenty-four patients with PMA, including 16 males and 8 females, aged 5-68 years old, admitted to Guangzhou First People's Hospital between March 1996 and January 2006 were recruited. Informed consents were obtained from all the patients. METHODS: All the patients subjected to EMG and detection of nerve conduction velocity at distal end of four extremities with a Keypoint evoked potential/ EMG instrument (Denmark). Sensory and motor conduction velocity, EMG changes of upper and lower extremities were observed, and relationship of neuroelectrophysiological characteristics and clinical symptoms was analyzed. MAIN OUTCOME MEASURES: Changes in sensory and motor conduction velocity, EMG and clinical manifestations of 24 patients. RESULTS: ① All the patients suffered from insidious onset and gradually progressive course of PMA. Muscular atrophy of lower extremity was found in 14 patients, and that of upper extremity in 5 patients. ②Routine nerve conduction study showed that sensory and motor conduction velocity were stepped down, especially in 16 patients with typeⅠPMA (demyelinating pattern, nerve conduction velocity below normal level 50%). Motor nerve conduction velocity of median nerve, ulnar nerve, common peroneal nerve and tibial nerve averaged 34.8 m/s, 37.2 m/s, 16.5 m/s and 17.4 m/s, respectively; Sensory nerve conduction velocity of median nerve, ulnar nerve and sural nerve averaged 27.9%, 24.6 m/s and 3.1 m/s, respectively. Slowing conduction velocity and muscular strength involvement were disproportionate, i.e. myasthenia was relatively lessened, sensory and motor conduction velocities were greatly decreased. Nerve conduction velocity in distal end of two lower extremities was not detected in 8 patients, but who could still walk. CONCLUSION: ①PMA of patients is characterized by insidious onset and gradually progressive course of disease. Clinical symptom is the base to diagnose PMA. ②Neuroelectrophysiological study is a simple and easy-to-operate means with good reproducibility in diagnosing PMA. Patients with abnormal myasthenia in lower extremity can be detected in the early stage.

Interventional therapy for intracranial aneurysms under neuroelectrophysiological monitoring

Objective To study the application of neuroelectrophysiological monitoring for interventional therapy of intracranial aneurysms. Methods 22 patients with intracranial aneurysm underwent neuroelectrophysiological monitoring during interventional therapy. Somatosensory evoked potential( SSEP) ,brainstem

A CLINICAL AND NEUROELECTROPHYSIOLOGICAL STUDY OF HYPERKALEMIC PERIODIC PARALYSIS

A case of atypical hyperkalemic periodic paralysis is reported. The diagnosis was confirmed by hyperkalemic test, cold water test, and differentiation of attack period and rest period by the measurement of motor nerve conduction amplitude. Etio-pathology of this disease is discussed from the view of neuroelectrophysiology.

Neuroelectrophysiological characteristics of Hirayama disease： report of 14 cases

Background Hirayama disease is a juvenile muscular atrophy of the distal upper extremities and affects mainly young males. The present study aimed to investigate the neuroelectrophysiological characteristics of Hirayama disease. Methods We retrospectively analyzed the neural conduction velocity （NCV） parameters and needle-electrode electromyograms （EMG） of 14 patients with Hirayama disease. According to the clinical features of the patients, NCV was performed on affected upper-limb including median nerves and ulnar nerves, while EMG was selectively performed on upper and lower extremities, sternocleidomast and thoracic paraspinal muscles. Results The median nerves of all affected upper limbs of patients with Hirayama disease had normal conduction velocities and compound motor action potentials （CMAPs）. The ulnar nerves of all affected upper limbs also had normal conduction velocities. Of the 16 measured ulnar nerves of the affected upper limbs, eight had normal CMAPS, while the other eight showed CMAPs below the normal value by 〉20%. All patients had neurogenic injury on the affected side in muscles innervated by anterior horn cells at the lower cervical region （C7-8, T1）. Four patients had unilateral upper-limb muscle neurogenic injury on the affected side. Seven patients had bilateral upper-limb muscle neurogenic injury, while only two patients experienced bilateral upper-limb muscle atrophy / weakness. The other three patients showed extensive neurogenic injury （unilateral upper-limb muscle atrophy/weakness in one patient, bilateral symptoms in the other two patients）. Conclusions Electromyographic examination showed that the majority of Hirayama disease patients exhibited characteristic segmental injury in the anterior horn of the lower cervical region, while a few patients exhibited extensive neurogenic injury. These data suggest that the actual influence of Hirayama disease may be more extensive than indicated by the clinical presentations.

Significance of Nueroelectrophysiological Tests in the Early Diagnosis of Sub-clinical Neuropathay with Diabetes Mellitus

Summary： To evaluate the application of nueroelectrophysiological tests in early diagnosis of sub-clinical neuropathy in diabetes mellitus （DM）, The routine nerve conductive velocity （NCV）, F-wave and sympathetic skin response （SSR） were detected in 27 patients with diabetes mellitus but without symptoms and signs of lesions of nerve system. Our results showed that 48.1%, 44.4 %, 51. 9 % of the patients were found to have abnormal NCV, F-wave and SSR respectively, The abnormalities were mainly characterized by prolonged latency, reduced velocity and absence of wave-form. There were significant differences between the controls and the DM group （P〈0,05）. Both the distal and proximal segments of nerves were affected and the distal lesions took place earlier than proximal ones and the changes in low extremities were more severe than those of upper extremities, F-wave can be used as a sensitive indicator for the early diagnosis of peripheral neuropathy and it can help to detect the subclincial lesions, SSR can be used for the evaluation of functional status of autonomic nerves in DM patients.

Saikosaponin a increases interleukin-10 expression and inhibits scar formation after sciatic nerve injury

Nerve scarring after peripheral nerve injury can severely hamper nerve regeneration and functional recovery.Further,the anti-inflammatory cytokine,interleukin-10,can inhibit nerve scar formation.Saikosaponin a（SSa） is a monomer molecule extracted from the Chinese medicine,Bupleurum.SSa can exert anti-inflammatory effects in spinal cord injury and traumatic brain injury.However,it has not been shown whether SSa can play a role in peripheral nerve injury.In this study,rats were randomly assigned to three groups.In the sham group,the left sciatic nerve was directly sutured after exposure.In the sciatic nerve injury（SNI） ＋ SSa and SNI groups,the left sciatic nerve was sutured and continuously injected daily with SSa（10 mg/kg） or an equivalent volume of saline for 7 days.Enzyme linked immunosorbent assay results demonstrated that at 7 days after injury,interleukin-10 level was considerably higher in the SNI ＋ SSa group than in the SNI group.Masson staining and western blot assay demonstrated that at 8 weeks after injury,type I and III collagen content was lower and nerve scar formation was visibly less in the SNI ＋ SSa group compared with the SNI group.Simultaneously,sciatic functional index and nerve conduction velocity were improved in the SNI ＋ SSa group compared with the SNI group.These results confirm that SSa can increase the expression of the anti-inflammatory factor,interleukin-10,and reduce nerve scar formation to promote functional recovery of injured sciatic nerve.

Nanoparticles carrying neurotrophin-3-modified Schwann cells promote repair of sciatic nerve defects

Schwann ceils and neurotrophin-3 play an important role in neural regeneration, but the secretion of neurotrophin-3 from Schwann cells is limited, and exogenous neurotrophin-3 is inactived easily in vivo. In this study, we have transfected neurotrophin-3 into Schwann cells cultured in vitro using nanoparticle liposomes. Results showed that neurotrophin-3 was successfully transfected into Schwann cells, where it was expressed effectively and steadily. A composite of Schwann cells transfected with neurotrophin-3 and poly（lactic-co-glycolic acid） biodegradable conduits was transplanted into rats to repair 10-mm sciatic nerve defects. Transplantation of the composite scaffold could restore the myoelectricity and wave amplitude of the sciatic nerve by electrophysiological examination, promote nerve axonal and myelin regeneration, and delay apoptosis of spinal motor neurons. Experimental findings indicate that neurotrophin-3 transfected Schwann cells combined with bridge grafting can promote neural regeneration and functional recovery after nerve injury.

Blockage of the habenular nucleus can eliminate dyspnea induced by electrostimulation of the insular cortex

BACKGROUND： The insular cortex and habenular nucleus may be a regulatory center for obstructive sleep apnea syndrome, and dyspnea may be caused by insular cortex activity. The insular cortex is a cortical representation of obstructive sleep apnea syndrome. The habenular nucleus is a station for descending insular cortex activity. OBJECTIVE： Through actively stimulating the rat insular cortex, to observe rat respiratory movement, myoelectric activities of genioglossus, arterial partial pressure of oxygen, partial pressure of carbon dioxide and acidity-alkalinity, and to verify a hypothesis that the insular cortex is a superior-position regulation center, and the habenular nucleus is an inferior-position nervous nuclei of the insular cortex in patients with obstructive sleep apnea syndrome. DESIGN, TIME AND SETTING： The randomized, controlled animal study was performed at the Laboratory of Electrophysiology, Department of Physiology, Norman Bathune College of Medicine, Jilin University, China from September 2004 to June 2008. MATERIALS： We used L-glutamic acid （Dingguo Biological Product Research Center, Beijing, China）, lidocaine hydrochloride （Seventh Pharmacy Co., Ltd., Wuxi, China）, electric stimulator （Nihon Kohden, Japan）, and an AVL-OPTI blood gas analyzer （AVL Scientific Co., Roswell, GA, USA）. METHODS： The insular cortex of healthy adult Wistar rats underwent electrostimulation and L-glutamic acid stimulation to record changes in the myoelectric activity of genioglossus and respiratory movement. Some rats were injected with lidocaine to block the habenular nucleus before electrostimulation or L-glutamic acid stimulation. L-glutamic acid and lidocaine were injected by microelectrodes embedded in nuclear groups. MAIN OUTCOME MEASURES： Myoelectric activities of genioglossus, arterial partial pressure of oxygen, partial pressure of carbon dioxide and acidity-alkalinity were measured following apnea in rats undergoing electrostimulation in the insular cortex and following blockade of the habenular nucleus. RESULTS： Following electrostimulation and L-glutamic acid stimulation, rats developed apnea or respiratory rhythm disorders. Simultaneously, the amplitude of myoelectric activity of the genioglossus was reduced （P 〈 0.01 ）, and the electromyogram integral was decreased （P 〈 0.01）. Arterial blood gas analysis showed arterial blood acidosis, a decrease in pH （P 〈 0.05）, and an increase in the negative value of alkaline reserve （P 〈 0.01）. Lidocaine in the habenular nuclear blocked respiratory and other index changes after insular cortex stimulation. CONCLUSION： Dyspnea induced by stimulating the insular cortex may require the habenular nucleus. Paralysis of the habenular nucleus can completely eliminate insular cortex stimulation-induced dyspnea.

Research progress in hepatic encephalopathy in recent 10 years A Web of Science-based literature analysis

OBJECTIVE： To analyze international research trends in hepatic encephalopathy and examine the role of neuroelectrophysiology and neuroimaging in diagnosis of hepatic encephalopathy. DATA RETRIEVAL： We performed a bibliometric analysis of studies on hepatic encephalopathy published during 2002-2011 retrieved from Web of Science. SELECTION CRITERIA： Inclusion criteria： （1） peer-reviewed published articles on hepatic encephalopathy; （2） original article, review, meeting abstract, proceedings paper, book chapter, editorial material, news items, and （3） published during 2002-2011. Exclusion criteria： （1） articles that required manual searching or telephone access; （2） documents that were not published in the public domain; and （3） corrected papers from the total number of articles. MAIN OUTCOME MEASURES： （1）Annual publication output; （2） type of publication; （3） publication by research field; （4） publication by journal; （5） publication by author; （6） publication by institution; （7） publication by country; （8） publication by institution in China; （9） most-cited papers. RESULTS： A total of 3 233 papers regarding hepatic encephalopathy were retrieved during 2002-2011. The number of papers gradually increased over the 10-year study period and was highest in 2010. Most papers appeared in journals with a focus on gastroenterology and hepatology. Among the included journals, Hepatology published the greatest number of papers regarding hepatic encephalopathy, and the published studies were highly cited. Thus, Hepatology appears to represent a key journal publishing papers on hepatic encephalopathy. Regarding distribution by country for publications on hepatic encephalopathy indexed in Web of Science during 2002-2011, the United States published highest number of papers, with China ranked ninth As per distribution by institute for publications, the University of Montreal in Canada published the highest number of papers （n = 111 ）. Among the Chinese institutes, Zhejiang University in China was the most prolific institute with 15 papers. CONCLUSION： The present bibliometric analysis on hepatic encephalopathy provides an overview of research progress, as well as identifying the most active institutes and experts in this research field during 2002-2011. Research into hepatic encephalopathy has revealed changes in neural injury and regeneration in hepatic encephalopathy. Neuroelectrophysiological and neuroimaging examinations are important for determining clinical classifications and disease severity of hepatic encephalopathy, providing a foundation for further research.

Multi-scale phase average waveform of electroencephalogram signals in childhood absence epilepsy using wavelet transformation

BACKGROUND： Recent studies have focused on various methods of wavelet transformation for electroencephalogram （EEG） signals. However, there are very few studies reporting characteristics of multi-scale phase waves during epileptic discharge.OBJECTIVE： To extract multi-scale phase average waveforms from childhood absence epilepsy EEG signals between time and frequency domains using wavelet transformation, and to compare EEG signals of absence seizure with pre-epileptic seizure and normal children, and to quantify multi-scale phase average waveforms from childhood absence epilepsy EEG signals. DESIGN, TIME AND SETTING： The case-comparative experiment was performed at the Department of Neuroelectrophysiology, Tianjin Medical University from August 2002 to May 2005. PARTICIPANTS： A total of 15 patients with childhood absence epilepsy from the General Hospital of Tianjin Medical University were enrolled in the study. The patients were not administered anti-epileptic drugs or sedatives prior to EEG testing. In addition, 12 healthy, age- and gender-matched children were also enrolled.METHODS： EEG signals were tested on 15 patients with childhood absence epilepsy and 12 normal children. Epileptic discharge signals during clinical and subclinical seizures were collected 10 and 20 times, respectively. The collected EEG signals were treated with wavelet transformation to extract multi-scale characteristics during absence epilepsy seizure using a conditional sampling method. Multi-scale phase average waveforms were collected using a conditional phase averaging technique. Amplitude of phase average waveform from EEG signals of epilepsy seizure, subclinical epileptic discharge, and EEG signals of normal children were compared and statistically analyzed in the first half-cycle.MAIN OUTCOME MEASURES： Multi-scale wavelet coefficient and the evolution of EEG signals were observed during childhood absence epilepsy seizures using wavelet transformation. Multi-scale phase average waveforms from EEG signals were observed using a conditional sampling method and phase averaging technique.RESULTS： Multi-scale characteristics of EEG signals demonstrated that 12-scale （3 Hz） rhythmical activity was significantly enhanced during childhood absence epilepsy seizure and co-existed with background structure （〈1 Hz, low frequency discharge）. The phase average wave exhibited opposed phase abnormal rhythm at 3 Hz. Prior to childhood absence epilepsy seizure, EEG detected opposed abnormal a rhythm and 3 Hz composition, which were not detected with traditional EEG. Compared to EEG signals from normal children, epileptic discharges from clinical and subclinical childhood absence epilepsy seizures were positive and amplitude was significantly greater （P〈0.05）.CONCLUSION： Wavelet transformation was used to analyze EEG signals from childhood absence epilepsy to obtain multi-scale quantitative characteristics and phase average waveforms. Multi-scale wavelet coefficients of EEG signals correlated with childhood absence epilepsy seizure, and multi-scale waveforms prior to epilepsy seizure were similar to characteristics during the onset period. Compared to normal children, EEG signals during epilepsy seizure exhibited an opposed phase model.

A rat pup model of cerebral palsy induced by prenatal inflammation and hypoxia

Animal models of cerebral palsy established by simple infection or the hypoxia/ischemia method cannot effectively simulate the brain injury of a premature infant. Healthy 17-day-pregnant Wistar rats were intraperitoneally injected with lipopolysaccharide then subjected to hypoxia. The pups were used for this study at 4 weeks of age. Simultaneously, a hypoxia/ischemia group and a control group were used for comparison. The results of the footprint test, the balance beam test, the water maze test, neuroelectrophysiological examination and neuropathological examination demonstrated that, at 4 weeks after birth, footprint repeat space became larger between the forelimbs and hindlimbs of the rats, the latency period on the balance beam and in the Morris water maze was longer, place navigation and ability were poorer, and the stimulus intensity that induced the maximal wave amplitude of the compound muscle action potential was greater in the lipopolysaccharide/hypoxia and hypoxia/ischemia groups than in the control group. We observed irregular cells around the periventricular area, periventricular leukomalacia and breakage of the nuclear membrane in the lipopolysacchadde/hypexia and hypoxia/ischemia groups. These results indicate that we successfully established a Wistar rat pup model of cerebral palsy by intraperitoneal injection of lipopolysaccharide and hypoxia.

Early cyclosporin A treatment retards axonal degeneration in an experimental peripheral nerve injection injury model

Injury to peripheral nerves during injections of therapeutic agents such as penicillin G potas-sium is common in developing countries. It has been shown that cyclosporin A, a powerful immunosuppressive agent, can retard Wallerian degeneration after peripheral nerve crush injury. However, few studies are reported on the effects of cyclosporin A on peripheral nerve drug in-jection injury. This study aimed to assess the time-dependent efifcacy of cyclosporine-A as an immunosuppressant therapy in an experimental rat nerve injection injury model established by penicillin G potassium injection. The rats were randomly divided into three groups based on the length of time after nerve injury induced by cyclosporine-A administration （30 minutes, 8 or 24 hours）. The compound muscle action potentials were recorded pre-injury, early post-injury （within 1 hour） and 4 weeks after injury and compared statistically. Tissue samples were taken from each animal for histological analysis. Compared to the control group, a significant im-provement of the compound muscle action potential amplitude value was observed only when cyclosporine-A was administered within 30 minutes of the injection injury （P 〈 0.05）; at 8 or 24 hours after cyclosporine-A administration, compound muscle action potential amplitude was not changed compared with the control group. Thus, early immunosuppressant drug therapy may be a good alternative neuroprotective therapy option in experimental nerve injection injury induced by penicillin G potassium injection.

Association of neuroelectrophysiology and analysis of cerebrospinal fluid immunoglobulin with pathogenetic conditions of patients with Guillain-Barre syndrome

BACKGROUND： Guillain-Barre syndrome （GBS） is an autoimmune disease which is characterized by demyelination of peripheral nerve and nerve root, and inflammatory reaction of lymphocyte and macrophage. Neuroelectrophysiological examination and cerebrospinal fluid （CSF） analysis are of significance for its diagnosis. OBJECTIVE： To study the association of neuroelectrophysiology and cerebrospinal fluid immunoglobulin （CSF-lg） with pathogenetic conditions of patients with GBS. DESIGN： Case control study SETTING： Department of Neurology, Shenzhen Municipal Shekou Group Hospital; Department of Neuroelectrophysiology, People＇s Hospital of Guangdong Province. PARTICIPANTS： A total of 32 GBS patients including 18 males and 14 females who aged from 17 to 72 years were selected as experimental group from the Department of Neurology, People＇s Hospital of Guang- dong Province from January 2004 to December 2005. All cases conformed with GBS diagnostic criteria established by Asbury in 1990 and they were divided into three types according to neurological criteria established by Chinese Neurology and Psychology Journal in 1993： mild, moderate and severe types. Another 30 patients with vascular headache were selected as control group from the same hospital including 14 males and 16 females who aged from 17 to 79 years. METHODS： ① Neuroelectrophysiological examination： Multiple-functional electromyography device provided by Nicolet Company, USA was used to measure nerve conduction velocity （NCV）, including motor nerve conduction velocity （MCV） and sensory nerve conduction velocity （SCV）; meanwhile, electromyologram （EMG）, somatosensory evoked potential （SEP） and electroencephalogram （EEG） were also measured. ② Detection of CSF-lg： Concentrations of IgG, IgA and IgM were measured with immunofixation electrophoresis. ③Follow-up： Among 32 GBS patients, 14 cases received follow-up after treatment and the longest fol- low-up time was 1 year after onset. Among them, 8 cases were reexaminined with neuroelectrophysiological and CSF examinations. MAIN OUTCOME MEASURES： Results of NCV, EMG, SEP and EEG; comparison of CSF-lg content; results of follow-up examinations. RESULTS： All 32 GBS cases and 30 patients with vascular headache were involved in the final analysis. ① Abnormal rate of neuroelectrophysiological test： 75% of NCV, 88% of F-wave, 53% of MCV, 25% of SEP, 47% of EMG and 31% of EEG. There were no significant differences among various types （P 〉 0.05）. ② Results of CSF-lg test： There were no significant differences among various types （P 〉 0.05）; however, abnormalities in experimental group was higher than those in control group （P 〈 0.01）. CONCLUSION ： Results of follow-up study suggest that improvement of clinical symptom is earlier than neuroelectrophysiological recovery; MCV and EMG recoveries are faster than that of NCV; the earlier the abnormality of EMG, the poorer the recovery. CSF4g recovers normally along improvement of clinical symptoms. It is of significance for neuroelectrophysiology and abnormality of CSF-Ig to determine degree of peripheral nerve demyelination and prognosis.

STUDY OF BEHAVIORAL TOXICOLOGY IN LEAD EXPOSED RATS

The study treated 72 s,rague-Dawley rats that were divided into 4 groups, one controlgroup and low, middle and higa dose groups, through drinking lead acetate solutions for threemonths. On the basis of founding subclinical lead poisoning model, behavioral toxicological testwhich consisted of neurobehavioral functions, neuroelectrophysiology and neurobiochemistry wascarried out. The results indicabo that low lvel lead exposure could result in the obvious changes orneurobehavioral function, neuroelectrophyslology and ueurobiochemistry, and the changes of neurobeltavioral runctiou had close correlatiom with P6B, Zap, NCV and DA, and they also had promlnant dose-response relatiouskips. The results suggested that the indexes of neurobehavioral functionmight be cousldered as early, semitive indexes for subolinical'lead poisoning. The combination ofneurobehavioral function with neuroectrophysiology could be used to evaluate the early neurotic toxicity of lead. The results also suggested that the change of dopamine metabolism of the central nervous system (CNS) might be one of the biological foundation of lead neurotic toxicity which changedthe neurobehavioral function of laboratory rats.

The sensitivity difference between the glans penis and penile shaft in primary premature ejaculation

The penis is a vital organ of perception that transmits perceived signals to ejaculation-related centers.The penis consists of the glans penis and penile shaft,which differ considerably in both histology and innervation.This paper aims to investigate whether the glans penis or the penile shaft is the main source of sensory signals from the penis and whether penile hypersensitivity affects the whole organ or only part of it.The thresholds,latencies,and amplitudes of somatosensory evoked potentials(SSEPs)were recorded in 290 individuals with primary premature ejaculation using the glans penis and penile shaft as the sensory areas.The thresholds,latencies,and amplitudes of SSEPs from the glans penis and penile shaft in patients were significantly different(all P<0.0001).The latency of the glans penis or penile shaft was shorter than average(indicating hypersensitivity)in 141(48.6%)cases,of which 50(35.5%)cases were sensitive in both the glans penis and penile shaft,14(9.9%)cases were sensitive in the glans penis only,and 77(54.6%)cases were sensitive in the penile shaft only(P<0.0001).There are statistical differences in the signals perceived through the glans penis and the penile shaft.Penile hypersensitivity does not necessarily mean that the whole penis is hypersensitive.We classify penile hypersensitivity into three categories,namely,glans penis,penile shaft,and whole-penis hypersensitivity,and we propose the new concept of penile hypersensitive zone.

Microelectrode Array-evaluation of Neurotoxic Effects of Magnesium as an Implantable Biomaterial

Magnesium （Mg）-based biomaterials have shown great potential in clinical applications. However, the cytotoxic effects of excessive Mg2. and the corrosion products from Mg-based biomaterials, particularly their effects on neurons, have been little studied. Although viability tests are most commonly used, a functional evaluation is critically needed. Here, both methyl thiazolyl tetrazolium （MTT） and lactate de- hydrogenase （LDH） assays were used to test the effect of Mg2. and Mg-extract solution on neuronal viability. Microelectrode arrays （MEAs）, which provide long-term, real-time recording of extracellular electro- physiological signals of in vitro neuronal networks, were used to test for toxic effects. The minimum effective concentrations （ECmin） of Mg2. from the MTr and LDH assays were 3 mmol/L and 100 mmol/L respec- tively, while the ECmin obtained from the MEA assay was 0.1 mmol/L MEA data revealed significant loss of neuronal network activity when the culture was exposed to 25% Mg-extract solution, a concentra- tion that did not affect neuronal viability. For evaluating the biocompatibility of Mg-based biomaterials with neurons, MEA electrophysiological testing is a more precise method than basic cell-viability testing.

Intraoperative neurophysiological monitoring in selective dorsal rhizotomy (SDR)

For decades,intraoperative neurophysiological monitoring(IONM)has been used to guide selective dorsal rhizotomy(SDR)for the treatment of spastic cerebral palsy(CP).Electromyography(EMG)interpretation methods,which are the core of IONM,have never been fully discussed and addressed,and their importance and necessity in SDR have been questioned for years.However,outcomes of CP patients who have undergone IONM-guided SDR have been favorable,and surgery-related complications are extremely minimal.In this paper,we review the history of evolving EMG interpretation methods as well as their neuroelectrophysiological basis.