Wearable and flexible electrochemical sensors for sweat analysis:a review

Flexible wearable sweat sensors allow continuous,real-time,noninvasive detection of sweat analytes,provide insight into human physiology at the molecular level,and have received significant attention for their promising applications in personalized health monitoring.Electrochemical sensors are the best choice for wearable sweat sensors due to their high performance,low cost,miniaturization,and wide applicability.Recent developments in soft microfluidics,multiplexed biosensing,energy harvesting devices,and materials have advanced the compatibility of wearable electrochemical sweat-sensing platforms.In this review,we summarize the potential of sweat for medical detection and methods for sweat stimulation and collection.This paper provides an overview of the components of wearable sweat sensors and recent developments in materials and power supply technologies and highlights some typical sensing platforms for different types of analytes.Finally,the paper ends with a discussion of the challenges and a view of the prospective development of this exciting field.

Ictal hypersalivation as a prominent symptom in a girl with insulo-opercular epilepsy

Introduction:Hypersalivation has been associated with Rolandic epilepsy and other childhood epilepsy syndromes.However,pure salivatory seizures are a rare type of focal seizure in which ictal hypersalivation is the dominant feature throughout the seizures.Case presentation:We present a case of pure salivatory seizures originating from the right post-central operculum cortex,confirmed by the favorable surgical outcome.We attempt to analyze the symptom from behavioral and neural network perspectives and propose a possible mechanism to generate ictal hypersalivation and pure salivatory seizures.Conclusion:Based on previous reports in the literature and our case,we emphasize the importance of the operculum in patients with ictal hypersalivation,particularly in patients with pure salivatory seizures.

Neuronal firing in the ventrolateral thalamus of patients with Parkinson＇s disease differs from that with essential tremor

Background Although thalamotomy could dramatically improve both parkinsonian resting tremor and essential tremor （ET）, the mechanisms are obviously different. This study aimed to investigate the neuronal activities in the ventrolateral thalamus of Parkinson＇s disease （PD） and ET. Methods Thirty-six patients （PD： 20, ET： 16） were studied. Microelectrode recordings in the ventral oral posterior （Vop）and the ventral intermediate nucleus （Vim） of thalamus was performed on these patients who underwent thalamotomy.Electromyography （EMG） was recorded simultaneously on the contralateral limbs to surgery. Single unit analysis and the interspike intervals （ISIs） were measured for each neuronal type. ISI histogram and auto-correlograms were constructed to estimate the pattern of neuronal firing. Mann-Whitney test and Kruskal-Wallis （K-W） test were used to compare the mean spontaneous firing rate （MSFR） of neurons of PD and ET patients. Results Three hundred and twenty-three neurons were obtained from 20 PD trajectories, including 151 （46.7%） tremor related neuronal activity, 74 neurons （22.9%） with tonic firing, and 98 （30.4%） neurons with irregular discharge. One hundred and eighty-seven neurons were identified from 16 ET trajectories including 46 （24.6%） tremor-related neuronal activity, 77 （41.2%） neurons with tonic firing, and 64 neurons （34.2%） with irregular discharge. The analysis of MSFR of neurons with tonic firing was 26.7 （3.4-68.3） Hz （n=74） and that of neurons with irregular discharge （n=98） was 13.9 （3.0-58.1） Hz in PD; whereas MSFR of neurons with tonic firing （n=77） was 48.8 （19.0-135.5） Hz and that of neurons with irregular discharge （n=64） was 26.3 （8.7-84.7） Hz in ET. There were significant differences in the MSFR of two types of neuron for PD and ET （K-W test, both P〈0.05）. Significant differences in the MSFR of neuron were also obtained from Vop and Vim of PD and ET （16.3 Hz vs. 34.8 Hz, 28.0 Hz vs. 49.9 Hz） （K-W test, both P 〈0.05）, respectively. Conclusion In consistent with recent findings, the decreased MSFR of neurons observed in the Vop is likely to be involved in PD whereas the increased MSFR of neurons seen in the Vim may be a cause of ET.

Neuronal firing in the globus pallidus internus and the ventrolateral thalamus related to parkinsonian motor symptoms

Background It has been proposed that parkinsonian motor signs result from hyperactivity in the output nucleus of the basal ganglia, which suppress the motor thalamus and cortical areas. This study aimed to explore the neuronal activity in the globus pallidus internus （GPi） and the ventrolateral thalamic nuclear group （ventral oral posterior/ventral intermediate, Vop/Vim） in patients with Parkinson＇s disease （PD）. Methods Twenty patients with PD who underwent neurosurgery were studied. Microelectrode recording was performed in the GPi （n=10） and the Vop/Vim （n=10） intraoperatively. Electromyography （EMG） contralateral to the surgery was simultaneously performed. Single unit analysis was carried out. The interspike intervals （ISI） and coefficient of variation （CV） of ISI were calculated. Histograms of ISI were constructed. A unified Parkinson＇s disease rating scale （UPDRS） was used to assess the clinical outcome of surgery. Results Three hundred and sixty-three neurons were obtained from 20 trajectories. Of 175 GPi neurons, there were 15.4% with tremor frequency, 69.2% with tonic firing, and 15.4% with irregular discharge. Of 188 thalamic neurons, there were 46.8% with tremor frequency, 22.9% with tonic firing, and 30.3% with irregular discharge. The numbers of three patterns of neuron in GPi and Vop/Vim were significantly different （P 〈0.001）. ISI analysis revealed that mean firing rate of the three patterns of GPi neurons was （80.9±63.9） Hz （n=78）, which was higher than similar neurons with 62.9 Hz in a normal primate. For the Vop/Vim group, ISI revealed that mean firing rate of the three patterns of neurons （n=95） was （23.2±17.1） Hz which was lower than similar neurons with 30 Hz in the motor thalamus of normal primates. UPDRS indicated that the clinical outcome of pallidotomy was （64.3±29.5）%, （83.4±19.1）% and （63.4±36.3）%, and clinical outcome of thalamotomy was （92.2±12.9）%, （68.0±25.2）% and （44.3±7.2）% for tremor, rigidity and bradykinesia, respectively. A significant difference of tremor and rigidity was found between GPi and VopNim （P 〈0.05）. Conclusions Different changes in neuronal firing rate and the pattern in GPi and Vop/Vim are likely responsible for parkinsonian motor signs. The results support the view that abnormal neuronal activity in GPi and Vop/Vim are involved in the pathophysiology of parkinsonism.

Leucine-rich glioma-inactivated protein 1 antibody-mediated autoimmune encephalitis in a 4-year-old girl:a case report

Background:Leucine-rich glioma-inactivated protein 1(LGI1)antibody-mediated encephalitis is a rare subtype of autoimmune encephalopathy,which is associated with autoimmunity against the neuronal plasma membrane proteins.The characteristic symptoms of this disease are memory dysfunction,seizures,faciobrachial dystonic seizures,cognitive deficits,neuropsychiatric disturbances,and intractable hyponatremia.The diagnosis of this disease mainly depends on the presence of anti-LGI1 antibody in serum or cerebrospinal fluid of patients.LGI1 antibody encephalitis has been reported mostly in adults,with rare occurrences in children.Case presentation:In this report,we described a 4-year-old girl with typical seizures.Seizure types included focal seizures and generalized tonic-clonic seizures.The electroencephalogram findings showed focal discharges.Brain magnetic resonance imaging(MRI)showed normal.The cerebrospinal fluid(CSF)levels of cells,glucose,and chloride were within the normal range,and the culture did not reveal growth of any pathogen.Test of serum LGI1-Ab was positive,while the tests for autoimmune encephalitis antibody series in CSF were negative.The seizures of the patient were completely controlled after the therapy of immunoglobulin,methylprednisolone and antiepileptic drugs(AEDs),and the mental state almost returned to normal.Conclusion:To our knowledge,the patient described here may be the youngest case of LGI1 antibody encephalitis reported to date.Children with the LGI1 antibody-associated encephalitis may present only with single symptoms such as epileptic seizures and have good response to the therapy of immunoglobulin,methylprednisolone and antiepileptic drugs.Our case report will provide hints for pediatricians in the diagnosis and treatment of LGI1-antibody encephalitis.

Resection of a dysembryoplastic neuroepithelial tumor in the precentral gyrus

Background:Dysembryoplastic neuroepithelial tumors(DNTs)are common causes of intractable epilepsy in pediatric epilepsy patients.The effect of surgical intervention is often limited when the tumor is located in the precentral gyrus.Furthermore,complete surgical resection is often not performed in order to avoid permanent neurological deficits.Methods:Here,we present a pediatric patient with intractable epilepsy caused by a simple DNT located in the precentral gyrus.Intracranial electrodes were implanted and used in combination with magnetic resonance imaging,video-electroencephalography and electrical cortical stimulation to assess neurological function,and where the epileptogenic zone was located.Results:The results of intracranial electrode monitoring suggested that the epileptogenic zone was located in the tumor area and that cortical function had been reorganized.We completely resected the tumor based on these findings.The patient has been seizure free after the surgery and has not had any neurological deficits.Conclusions:Simple form DNTs in the precentral gyrus can be completely resected with careful preoperative assessment of cortical function.Cortical reorganization could partly explain the functional preservation after surgery.

Correction to:Leucine-rich gliomainactivated protein 1 antibody-mediated autoimmune encephalitis in a 4-year-old girl:a case report

Correction to:Acta Epileptologica 3,4(2021)https://doi.org/10.1186/s42494-021-00039-z After publication of this article[1],it is reported the below corrections need to be made with it.1.The following sentence need to be added to the end of‘Background’section:“This study was approved by the Institutional Ethics Committee of Qilu Children’s Hospital of Shandong University and informed consent has been obtained from the guardian of patient prior to analysis.”