ABSTRACT
We report a single-beam synthetic gradiometer operated in the spin-exchange-relaxation free (SERF) regime, using the structure of two separate atomic vapor cells spaced 2â cm apart. To improve the capability of the gradiometer in suppressing the common-mode magnetic field noise, we are aiming at investigating the effects of the system parameters on the gradiometer common-mode rejection ratio (CMRR). The mathematical expression for the relationship between the gradiometer CMRR and the two variables including the linewidth ratio and the pumping factor ratio is constructed for the first time, to our knowledge. This means that the CMRR can be optimized by controlling the linewidth and the pumping factor, which is easy to implement in the operation process. As a result, a CMRR of 246 is achieved and a gradiometer sensitivity of 4.5â fT/cm/Hz1/2 is also measured. This method provides a theoretical and experimental basis for the automated operation of gradiometers, and the gradiometer system performance can be tuned to a desired state by simply controlling the linewidth and the incident light intensity.
ABSTRACT
The power conversion efficiency (PCE) and stability of n-i-p perovskite solar cells (PSCs) are significantly affected by inherent defects of SnO2 and perovskite layers. In this work, we incorporate 2-bromo-3-thiophenic acid (BrThCOOH) as a multifunctional passivant to simultaneously passivate the defects of SnO2 surface and perovskite layer. BrThCOOH permeates evenly into the MAPbI3 and coordinates with Pb2+ and iodine vacancies (VI+) to reduce surface defect density and inhibit the decomposition of MAPbI3. Carboxylic acid effectively passives the oxygen vacancy on the surface of SnO2 through coordination bonds, reducing the probability of electron capture by SnO2 surface defects, thus contributing to electron transport in device. The interaction of BrThCOOH with MAPbI3 and SnO2 surfaces leads to an upward shift in energy levels, reducing energy loss during charge migration. The optimal MAPbI3 device with BrThCOOH-modified SnO2 (T-SnO2) reveals an improved PCE of 21.12%, much higher than that of the control one (19.12%). The hydrophobicity of BrThCOOH-modified MAPbI3 is also improved, which is beneficial to the durability of the device. After 100 h of storage in the environment, the generated PSCs maintain their initial PCE of 75%, demonstrating excellent long-term stability without any encapsulation.
ABSTRACT
We first report a single-light-source orthogonally pumped triaxial atomic magnetometer with a double-cell structure. By using a beam splitter to equally allocate the pump beam, the proposed triaxial atomic magnetometer is responsive to magnetic fields in all three directions, and without sacrificing system sensitivity. The experimental results indicate that, the magnetometer achieves a sensitivity of 22â fT/Hz1/2 in x-direction with a 3-dB bandwidth of 22â Hz, a sensitivity of 23â fT/Hz1/2 in y-direction with a 3-dB bandwidth of 23â Hz, and a sensitivity of 21â fT/Hz1/2 in z-direction with a 3-dB bandwidth of 25â Hz. This magnetometer is useful for the applications that require the measurements of the three components of the magnetic field.
ABSTRACT
Wearables developed for human body signal detection receive increasing attention in the current decade. Compared to implantable sensors, wearables are more focused on body motion detection, which can support human-machine interaction (HMI) and biomedical applications. In wearables, electromyography (EMG)-, force myography (FMG)-, and electrical impedance tomography (EIT)-based body information monitoring technologies are broadly presented. In the literature, all of them have been adopted for many similar application scenarios, which easily confuses researchers when they start to explore the area. Hence, in this article, we review the three technologies in detail, from basics including working principles, device architectures, interpretation algorithms, application examples, merits and drawbacks, to state-of-the-art works, challenges remaining to be solved and the outlook of the field. We believe the content in this paper could help readers create a whole image of designing and applying the three technologies in relevant scenarios.
Subject(s)
Biosensing Techniques , Myography , Algorithms , Electric Impedance , Electromyography , Humans , Mechanical Phenomena , Myography/methodsABSTRACT
BACKGROUND: The application of Pickering emulsion stabilized by food-derived particles is of great interest in the food field, including meat processing. However, the creaming phenomenon is a thorny problem and may impact the resulting product quality. Here, we used polysaccharide nanoparticles from Flammulina velutipes (FVPN) as a stabilizer to prepare a oil/water Pickering emulsion and partly replace the original fat of common emulsified sausage, focusing on exploring the influence of phase separation on the sausage's techno-functional and sensory quality, with the aim of developing a new alternative fat substitute. RESULTS: Reformulated sausages showed increases in moisture (53.24-64.85%) and protein content (11.97-12.76%), but were reduced in fat content (27.28-18.76%). The increased FPOE (FVPN-palm oil emulsion; substitution rate 5-37%) amount in sausages resulted in significantly reduced (P < 0.05) cooking loss (18.87-8.63%). Meanwhile, emulsion improved the springiness and cohesiveness of sausage and significantly reduced (P < 0.05) hardness and chewiness when the replacement amount was less than 20%. Experimental sausages attained a more compact pore structure without harming sensory characteristics. Compared with creaming emulsion, pristine emulsion resulted in a sausage with higher moisture content, lower cooking loss, better elasticity and denser structure. CONCLUSION: The characteristics of sausages could be influenced by emulsion stability. Emulsion, especially with no creaming, can be effectively used as fat substitute at a level of 20% or less without adversely affecting the sensory characteristics of emulsified sausages. The incorporation of FPOE provides the potential for developing a new alternative approach for animal fat improvement in meat products. © 2019 Society of Chemical Industry.
Subject(s)
Fat Substitutes/analysis , Flammulina/chemistry , Food Additives/analysis , Meat Products/analysis , Polysaccharides/analysis , Animals , Cooking , Emulsions/chemistry , Food Handling , Hardness , Humans , Nanoparticles/chemistry , Palm Oil/analysis , Swine , Taste , Water/analysisABSTRACT
BACKGROUND: Edible packaging and coating with natural antimicrobials such as essential oils is an emerging technology for the control of pathogen growth in meat products. This study aimed to explore ethyl cellulose (EC) of three viscosities for the structuring of cinnamon essential oil (CEO), and investigated the physicochemical properties of the resulting oleogel and its emulsion, as well as the corresponding antibacterial activity in model and actual environments (as in sausages). RESULTS: The network structure of CEO-EC oleogel was more compact with increased EC viscosity, thereby improving the binding capacity and stability of the oil. A positive correlation was found between EC viscosity and particle size of the CEO-EC emulsion. The 45 cP CEO-EC emulsion exhibited greatest antimicrobial activitiy in models with Escherichia coli (E. coli) O157:H7 (ATCC 700927) and Staphylococcus aureus (S. aureus) (ATCC 29213), as well as in sausage, with respect to total counts of mesophilic bacteria, psychrotrophs, lactobacilli, and pseudomonads. CONCLUSION: The CEO-EC oleogel has antibacterial activity, determined by the EC viscosity, that provide potential antibacterial protection for meat products and might be especially suitable for some traditional Chinese ready-to-eat sausages without strictly sealed packaging. © 2019 Society of Chemical Industry.
Subject(s)
Anti-Bacterial Agents/chemistry , Cellulose/analogs & derivatives , Cinnamomum zeylanicum/chemistry , Oils, Volatile/chemistry , Oils, Volatile/pharmacology , Plant Oils/chemistry , Anti-Bacterial Agents/pharmacology , Cellulose/chemistry , Escherichia coli O157/drug effects , Escherichia coli O157/growth & development , Listeria monocytogenes/drug effects , Listeria monocytogenes/growth & development , Microbial Sensitivity Tests , Organic Chemicals/chemistry , Organic Chemicals/pharmacology , Plant Oils/pharmacology , Staphylococcus aureus/drug effects , Staphylococcus aureus/growth & development , ViscosityABSTRACT
Transglutaminase (TGase) catalyzing crosslinking between intra- and inter-chain glutamine and lysine peptide residues has been used for modifying protein's structure. However, its enzymatic performance on albuminoids such as collagen was still not completely illustrated. Herein, we investigated the crosslinking efficiency of films preheated at different temperatures and estimated its physicochemical properties. The electrophoresis results showed that the extracted collagen had typical triple helix structure but reduced and even disappeared as temperature increased. Accordingly, X-ray diffraction (XRD) indicated that the amount of triple helices decreased, corresponding to the decreases in thermal stability and mechanical properties of films. TGase crosslinking decreased the thickness of all films, while mechanical properties and thermal stability had a significant improvement especially at 45⯰C and 65⯰C. With the proper equilibrium of denature temperature and TGase crosslinking, the tailored film-forming properties of collagen can offer a potential to engineer collagenic material for biodegradable and edible packaging applications.
Subject(s)
Collagen/chemistry , Cross-Linking Reagents/chemistry , Temperature , Transglutaminases/chemistry , Transglutaminases/metabolism , X-Ray DiffractionABSTRACT
"Noxious stimulation over the foot can evoke a nociceptive flexor reflex (NR) in the lower limb especially for tibialis anterior muscle (TA). Components of NR include the monosynaptic fast latency NRII, and the polysynaptic slow latency NRIII, supposedly a spinal segmental reflex influenced by the supraspinal control. Pain perception is quantified by visual analogous scale (VAS) and has been reported to be related to NRIII. Previous papers have reported the long lasting effect of transcranial magnetic stimulation (TMS), as well as TMS suppressing pain perception. The purpose of this study was to investigate the immediate and prolonged effect of a single-pulse TMS to suppress NR and pain. NRIII was provoked at right TA by a train of electrical stimulation on the right toe in 10 healthy subjects. TMS was delivered over the vertex area to evoke right anterior tibialis muscle activity. A sham TMS from different directions of the coil was performed on the next day. The NRIII amplitude and VAS were measured. As a result, the amplitude of NRIII was significantly decreased than the control 50 ms pre-stimulation (0.20 ± 0.13 mA vs . 0.65 ± 0.42 mV, P = 0.016), 100 ms pre-stimulation (0.10 ± 0.10 mA vs . 0.65 ± 0.42 mV, P = 0.001), 15 min post-stimulation (0.12 ± 0.09 mA vs . 0.65 ± 0.42 mV, P = 0.004), and 30 min post-stimulation (0.41 ± 0.21 mA vs . 0.65 ± 0.42 mV, P = 0.046). VAS was diminished compared with the control 50 ms pre-stimulation (3.3 ± 0.9 vs . 5.4 ± 1.3, P = 0.002), 100 ms pre-stimulation (2.6 ± 0.5 vs . 5.4 ± 1.3, P < 0.001) and 15 min post-stimulation (3.5 ± 0.9 vs . 5.4 ± 1.3, P = 0.046). The NRIII amplitude was well correlated with VAS in reduction during the TMS condition and 15 min after electrical stimulation (P < 0.001). The sham TMS did not suppress NRIII or VAS. In conclusion, our results indicate that NRIII and the nociception can be inhibited by one single pulse TMS and such an effect can last for a period of time."
Subject(s)
Motor Cortex , Transcranial Magnetic Stimulation , Electric Stimulation , Humans , Pain Perception , ReflexABSTRACT
The Treatment Guideline Subcommittee of the Taiwan Headache Society evaluated both the acute and the preventive treatments for cluster headache now being used in Taiwan, based on the principles of evidence- based medicine. We assessed the quality of clinical trials and levels of evidence, and referred to other treatment guidelines proposed by other countries. Throughout several panel discussions, we merged opinions from the subcommittee members and proposed a consensus on the major roles, recommended levels, clinical efficacy, adverse events and cautions of clinical practice regarding acute and preventive treatments of cluster headache. The majority of Taiwanese patients have episodic cluster headaches, because chronic clusters are very rare. Cluster headache is characterized by severe and excruciating pain which develops within a short time and is associated with ipsilateral autonomic symptoms. Therefore, emergency treatment for a cluster headache attack is extremely important. Within the group of acute medications currently available in Taiwan, the subcommittee determined that high-flow oxygen inhalation has the best evidence of effectiveness, followed by intranasal triptans. Both are recommended as first-line medical treatments for acute attacks. Oral triptans were determined to be second-line medications. For transitional prophylaxis, oral corticosteroids are recommended as the first-line medication, and ergotamine as the second-line choice. As for maintenance prophylaxis, verapamil has the best evidence and is recommended as the first-line medication. Lithium, melatonin, valproic acid, topiramate and gabapentin are suggested as the second-line preventive medications. Surgical interventions, including occipital nerve stimulation, deep brain stimulation, radiofrequency block of the sphenopalatine ganglion, percutaneous radiofrequency rhizotomy and trigeminal nerve section, are invasive and their long-term efficacy and adverse events are still not clear in Taiwanese patients; therefore, they are not recommended currently by the subcommittee. The transitional and maintenance prophylactic medications can be used together to attain treatment efficacy. Once the maintenance prophylaxis achieves efficacy, the transitional prophylactic medications can be tapered gradually. We suggest the corticosteroids be used within two weeks, if possible. The duration of maintenance treatment depends on the individual patient's clinical condition, and the medications can be tapered off when the cluster period is over.
Subject(s)
Cluster Headache/drug therapy , Acute Disease , Cluster Headache/prevention & control , Humans , Practice Guidelines as TopicABSTRACT
Detecting a change in sound duration is important in language processing. The cerebral reactivity to a duration deviant in oddball paradigm has been reflected as a mismatch negativity (MMN). This study aimed to see cerebral responses to several duration-varying sounds presented with equal probability. Magnetoencephalographic (MEG) and behavior responses to equi-probable sounds (25-50-75-100-125 ms or 50-75-100-125-150 ms tones) were recorded in 10 healthy adult volunteers. By subtracting the average of the responses to 4 longer tones from the response to the shortest tone, a clear deflection peaking at 100-200 ms from stimulus onset was identified. This activity was called as sub-standard MMNm, and its amplitude tended to increase with the increment of duration deviance within a stimulation paradigm. The source of sub-standard MMNm was localized in superior temporal area, with 5-6 mm more anterior to the generator of N100m response. Behavioral tests also showed best performance in the recognition of the shortest tone than longer tones. In conclusion, the preferential response to the shortest tone in an equiprobable paradigm suggests an asymmetrical processing in the auditory cortex for duration-varying sounds.
Subject(s)
Auditory Cortex/physiology , Auditory Pathways/physiology , Magnetoencephalography , Pitch Perception , Psychoacoustics , Signal Detection, Psychological , Acoustic Stimulation , Adult , Audiometry , Auditory Threshold , Evoked Potentials, Auditory , Female , Humans , Male , Reaction Time , Time Factors , Young AdultABSTRACT
OBJECTIVE: Differences in physical features and occurrence probability between standards and deviants in oddball paradigms provide contributions to magnetic mismatch negativity (MMNm). We aimed to reduce these influential factors and extract memory-based MMNm by adding a control paradigm. METHODS: Magnetoencephalographic responses were recorded in 13 healthy adults with an oddball paradigm (125-ms standard and 50-ms deviant tones) and an equiprobable control paradigm (50-ms control and four other duration-varying tones). The stimulus onset asynchrony was 500 ms. Controlled MMNm was obtained by subtracting control-evoked responses from deviant-evoked responses. RESULTS: With respect to the onset of stimulus difference, the peak latency of controlled MMNm was compatible with previous intracranial MMN recordings. Both controlled and traditional MMNm were generated around the superior temporal cortex, whereas the controlled MMNm amplitude was about 70% of traditional MMNm amplitude. Right-hemispheric dominance was observed in traditional MMNm but not in controlled MMNm. N100m amplitude was smaller in standard-evoked than in deviant- or control-evoked responses. CONCLUSIONS: Controlled MMNm reflects memory-based processing of duration changes, whereas traditional MMNm additionally involves non-memory activations related to differential refractoriness states and physical properties between standard and deviant stimuli. SIGNIFICANCE: The memory-based processing of auditory deviants may be preferentially extracted by adding a control paradigm.
Subject(s)
Contingent Negative Variation/physiology , Evoked Potentials, Auditory/physiology , Magnetoencephalography , Memory/physiology , Acoustic Stimulation/methods , Adult , Analysis of Variance , Brain Mapping , Female , Functional Laterality/physiology , Humans , Male , Neuropsychological Tests , Reaction Time/physiology , Young AdultABSTRACT
To study the phase and power characteristics of brain oscillations during the preattentive detection of auditory deviance, we recorded magnetoencephalographic responses in 10 healthy subjects with an oddball paradigm. As the subject was watching a silent movie, standard tones (1000-Hz frequency, 100-ms duration) and their duration deviants (50-ms duration, probability of 15%) were randomly delivered binaurally. In addition to localizing the magnetic counterpart of mismatch negativity (MMNm) with equivalent current dipole modeling, we also measured the phase-locking value (PLV) and power change of the oscillatory responses to standard and deviant stimuli by employing the Morlet wavelet-based analysis. The MMNm signals peaking at 150-200ms after the onset of deviant were localized in bilateral temporal regions with larger amplitudes in the right hemisphere. Then 50ms after the onset of either standard or deviant stimuli, we observed an increase of PLV and power of theta and alpha oscillations in bilateral temporal regions. PLVs of theta and alpha activities to deviant stimuli were significantly larger in the right than left hemisphere (P<0.001). Compared with standard stimuli, deviants elicited a larger theta PLV (P<0.001) at 150-300ms and a larger theta power change (P<0.05) at 50-300ms for the responses in the right temporal region. In addition, a prominent theta phase-locking of deviant-elicited responses was found in the right frontal area at 110-250ms (P<0.01). Our current data suggest that a pronounced phase and power modulation on sound-elicited theta oscillations might characterize the change detection processing in the temporo-frontal network as reflected by the mismatch negativity.
Subject(s)
Auditory Perception/physiology , Brain Mapping , Frontal Lobe/physiology , Signal Detection, Psychological/physiology , Theta Rhythm , Acoustic Stimulation/methods , Adult , Contingent Negative Variation/physiology , Evoked Potentials, Auditory/physiology , Female , Humans , Magnetoencephalography , Male , Reaction Time/physiology , Spectrum Analysis , Time Factors , Young AdultABSTRACT
Studies suggest that smaller hippocampal volume predicts Alzheimer's disease (AD) in mild cognitive impairment (MCI). However, few studies have demonstrated decline rates in cognition and hippocampal volume in MCI subjects with stable clinical presentation. Furthermore, the effects of apolipoprotein E (ApoE) on the change rates of medial temporal structures and cognition in MCI are rarely investigated. Fifty-eight subjects with amnestic MCI and 20 normal aging elderly controls received annual neuropsychological and magnetic resonance imaging (MRI) assessments. Annual decline rates in neuropsychological test scores, hippocampal and amygdalar volumes were calculated. ApoE genotypes were examined. Nineteen (32.7%) MCI subjects converted to AD during an average 22.5-month follow-up period. The annual hippocampal atrophy rate was correlated with a decline in memory test scores. The presence of the ApoE varepsilon4 allele did not affect the change rates in neuropsychological test scores and medial temporal structures volume. Compared to subjects with stable MCI (MCI-S) and normal aging, progressive MCI (MCI-P) had the highest annual decline rates in cognition and hippocampal volume. Logistic regression analysis showed that higher annual decline rates in hippocampal volume and global cognitive test scores were associated with conversion to AD. Furthermore, although MCI-S subjects had little cognitive decline, their hippocampal atrophy rates were higher than those of normal aging controls. Therefore, accelerated hippocampal atrophy rates may be an early and important presentation in MCI subjects.
Subject(s)
Alzheimer Disease/diagnosis , Amnesia/diagnosis , Cognition Disorders/diagnosis , Hippocampus/pathology , Magnetic Resonance Imaging , Aged , Aged, 80 and over , Atrophy , Disease Progression , Female , Follow-Up Studies , Humans , Male , Neuropsychological Tests/statistics & numerical data , Organ Size/physiology , Prospective Studies , PsychometricsABSTRACT
BACKGROUND/PURPOSE: The objectives of this study were to: (1) survey migraine diagnoses among neurological outpatients in Taiwan; (2) compare neurologists' migraine diagnoses with the International Classification of Headache Disorders 2nd Edition (ICHD-2) criteria; and (3) evaluate the diagnostic ability of screening items on a patient migraine questionnaire. METHODS: This prospective study surveyed patients who consulted neurologists for the first time with a chief complaint of headache, excluding those experiencing headaches for > or = 15 days/month. Each neurologist interviewed a maximum of 10 patients. Patients were asked to complete a self-administered questionnaire and their physicians completed another questionnaire. The physicians were asked if patients could be diagnosed with migraine. In addition, a diagnosis of ICHD-2 migraine was made by the physician's questionnaire through a computer-generated algorithm. In this study, migraine without aura (code 1.1) or migraine with aura (code 1.2) were designated as "strict migraine", and the combination of strict migraine and ICHD-2 probable migraine (code 1.6) as "any migraine". RESULTS: Among 755 patients who were eligible for analysis, 537 (71%) were diagnosed as having "any migraine", 363 (48%) with "strict migraine", and 451 (60%) with physician-diagnosed migraine. Among the 537 patients diagnosed as having "any migraine", 308 patients (57%) had not been diagnosed by any physician before. A moderate agreement (kappa statistic around 0.5) was found between the physicians' diagnoses and ICHD-2 "strict migraine" or "any migraine". In patients with ICHD-2 probable migraine (n = 174), only 52% were diagnosed with migraine by our physicians. Nausea was the best single item for predicting migraine diagnosis, while any combination of two items among nausea/vomiting, moderate or severe pain and photophobia, provided the optimum screening tool. CONCLUSION: Migraine was the most common headache diagnosis in the neurologists' clinics. Probable migraine was not completely adopted as a migraine spectrum among neurologists. In contrast to ID Migraine(TM), moderate or severe headache intensity replaced headache-related disability as one screening item for migraine in Taiwan.
Subject(s)
Migraine Disorders/diagnosis , Adult , Humans , Male , Neurology , Prospective Studies , Surveys and Questionnaires , TaiwanABSTRACT
A 48-year-old woman suddenly lost consciousness as a result of a right rostral pontine tegmentum haemorrhage. The patient presented with decerebrate rigidity (DR) and regained full consciousness 5 days after the initial onset. The patient was given gabapentin 1200 mg/day nasogastrically and her DR significantly improved, although other antiepileptic drugs such as phenytoin and carbamazepine were given in larger dosages to decrease muscle hypertonicity. The patients' preserved consciousness and motor-evoked potentials to transcranial magnetic stimulation indicated a derangement of the extrapyramidal tracts with preservation of the pyramidal tracts. This case report discusses the possible mechanisms of action of gabapentin in DR.
Subject(s)
Amines/therapeutic use , Cyclohexanecarboxylic Acids/therapeutic use , Decerebrate State/drug therapy , gamma-Aminobutyric Acid/therapeutic use , Amines/administration & dosage , Anticonvulsants/administration & dosage , Anticonvulsants/therapeutic use , Cerebral Hemorrhage/complications , Cyclohexanecarboxylic Acids/administration & dosage , Decerebrate State/physiopathology , Female , Gabapentin , Humans , Intubation, Gastrointestinal , Middle Aged , Pons/pathology , Pons/physiopathology , Time Factors , Transcranial Magnetic Stimulation/methods , Treatment Outcome , Unconsciousness/etiology , Unconsciousness/physiopathology , gamma-Aminobutyric Acid/administration & dosageABSTRACT
OBJECTIVE: This study is aimed to explore the frequency characteristics of pain-evoked neuromagnetic responses in the secondary somatosensory (SII) cortices. METHODS: Thulium-laser nociceptive stimuli to the left hand dorsum of 10 right-handed healthy adults. The pain stimuli were rated as mild, moderate, and severe levels according to subjects' reports on a 10-point visual analog scale. We analyzed their cortical responses with wavelet-based frequency analyses and equivalent current dipole (ECD) modeling. RESULTS: For each pain level, we found an increase of theta (4-8 Hz) and alpha (8-13 Hz) power in bilateral SII areas at 180-210 ms after stimulus onset. The power was larger for the moderate than for the mild pain level (p < 0.05), but there was no statistical power difference of these oscillations between moderate and severe pain stimulus conditions (p = 0.7). Within the SII area, we did not observe particular difference in theta and alpha ECD locations between varying pain level conditions. CONCLUSIONS: The 4-13 Hz activities, peaking from 180 to 210 ms, are oscillatory correlates of SII activation in response to nociceptive stimulation, but their power may code the magnitude of pain stimuli only up to moderate level, as rated subjectively. This measure could be potentially used to evaluate SII activation in further pain studies.
Subject(s)
Biological Clocks/physiology , Nociceptors/physiology , Pain/physiopathology , Somatosensory Cortex/physiology , Action Potentials/physiology , Adult , Afferent Pathways/physiology , Evoked Potentials/physiology , Female , Humans , Lasers , Magnetoencephalography/methods , Male , Neural Conduction/physiology , Pain Measurement , Physical Stimulation , Reaction Time/physiology , Signal Processing, Computer-Assisted , Somatosensory Cortex/anatomy & histologyABSTRACT
Objectives. Sacral root stimulation (SRS) is a technique to restore the idiopathic overactive bladder (IOB). However, its mechanism of action is yet to be elucidated. Hence, we studied whether SRS restored IOB through the mechanism of spinal neuromodulation. Materials and Methods. Six IOB patients and 10 healthy volunteers were included in the study. The spinal nociceptive reflex was used as the index of spinal excitability and was evoked by electrical stimulation at the foot, with recording at the ipsilateral tibialis anterior. Results. IOB patients had increased spinal excitability to somatic nociceptive stimuli of the lower limbs. This spinal excitability decreased and bladder function improved after SRS, an effect that outlasted actual stimulation by at least 30 min. Conclusions. Our results showed that spinal excitability was increased in response to somatic nociceptive afferents in IOB patients. SRS restored bladder function, at least, in part, through spinal neuromodulation.
ABSTRACT
BACKGROUND: Kennedy's disease (KD) is an X-linked recessive polyglutamine disease. Traditionally, it is a lower motor neuron syndrome with additional features such as gynecomastia and tremor. Sensory symptoms are minimal if ever present. We used multimodal evoked potential (EPs) tests to study the distribution of the involvement of the disease. METHODS: Visual, brainstem auditory, somatosensory and motor EPs were studied in six KD patients. All of them had typical presentations and had been proved genetically. RESULTS: Abnormal findings were noted as follows: prolonged peak latencies of visual EPs, increased hearing threshold level, inconsistent brainstem auditory EPs, decreased amplitudes of cortical potentials of somatosensory EPs, and increased motor threshold to transcranial magnetic stimulation. CONCLUSIONS: Our multimodal EP studies showed that KD involved multiple levels of the nervous system. It implies the widespread effects of the mutant androgen receptors.
Subject(s)
Evoked Potentials/physiology , Muscular Atrophy, Spinal/diagnosis , Muscular Atrophy, Spinal/physiopathology , Nervous System/physiopathology , Neural Pathways/physiopathology , Acoustic Stimulation , Adult , Aged , Brain Stem/physiopathology , Electric Stimulation , Evoked Potentials, Auditory/physiology , Evoked Potentials, Motor/physiology , Evoked Potentials, Somatosensory/physiology , Evoked Potentials, Visual/physiology , Humans , Male , Middle Aged , Mutation/genetics , Neural Conduction/physiology , Neurologic Examination , Photic Stimulation , Predictive Value of Tests , Receptors, Androgen/genetics , Spinal Cord/physiopathology , Transcranial Magnetic StimulationABSTRACT
BACKGROUND/PURPOSE: The palmomental reflex (PMR) is a brief contraction of the mentalis muscles caused by a scratch over the thenar eminence, i.e. a brainstem reflex to afferents of upper limb. Using electrophysiologic methods, we studied the characteristics of brainstem excitability in PMR subjects. METHODS: Ten healthy PMR subjects were included in the study. Brainstem excitability was assessed with electrical stimulation at the trigeminal nerve, median nerve, ulnar nerve, and sural nerve with recordings at the mentalis muscles. A comparison was made by the probability between the mechanical scratch and the electrical stimulation to evoke the visible muscle contraction of mentalis. RESULTS: An electrical stimulus was able to elicit mentalis muscle responses (MMR(electrical)) in all the subjects if the stimulus was of sufficient strength. Using electrical stimulation, the median nerve at the wrist was the best site to evoke MMR(electrical). However, in PMR subjects, the probability of MMR(electrical) to median nerve stimulation was less than that of MMR(scratch), i.e. the clinical findings of PMR. Significantly lower thresholds and higher amplitudes were noted in PMR subjects only when the median nerve was stimulated. The onset latency did not show any difference between the two groups despite the stimulation sites. CONCLUSION: The facial motor neurons to median nerve stimulation are more sensitive in PMR subjects. In healthy PMR subjects, this indicates that the excitability increases only in the specific neuronal circuits between the lower cervical spinal cord and the facial motor nucleus in the rostral medulla. MMR(electrical) is a physiologic phenomenon, and PMR is a sign of increased brainstem excitability.