Female Methods
Sujoy K. Guba in Bioengineering in Reproductive Medicine, 2020
An extension of the electromyographic technique known as sacral evoked response is now being practised in may urological units. EMG monitoring alone gives an indication of the natural activity but is inadequate to investigate the total neurogenic reflex path. Evoked response is the outcome of a controlled stimulus. The site of stimulus and of the response recording may be so selected that the neural pathway of interest figures in the response to the input. For the micturition system a neural integration center is the sacral S2-S4 spinal segment. The sacral evoked response examines the reflex via this center and is more specific than the bulbocavernosus reflex. Neuropathic, myopathic and functional bladder disorders can be distinguished. Lesions of the conus medullaris or cauda equina can also be localized.
Electrodiagnosis
Mark V. Boswell, B. Eliot Cole in Weiner's Pain Management, 2005
An evoked potential (EP) is generally defined as an electrical manifestation of the central and peripheral neural pathways in response to an external stimulus. In simple terms, when an electrical, mechanical, visual, auditory, or other stimulus is applied, the body responds in a predictable manner, propagating electrical impulses. These impulses can be recorded and assessed for speed and volume of conduction, as well as aberrance. For the most part, these studies evaluate sensory pathways, including both peripheral and central components, with the exception of motor evoked potentials (MEPs). The three most common EPs in daily clinical practice are (1) somatosensory evoked potentials (SEPs), (2) brainstem auditory evoked potentials (BAEPs), and (3) pattern-shift visual evoked potentials (VEPs). Each of the studies provides an objective measurement of function relating to their respective sensory systems. Although each study is best suited for specific clinical purposes, the clinical benefits of all EPs lie within the ability to demonstrate aberrant function within the sensory systems when clinical examination is equivocal, define the anatomic distribution of a neural pathology, and even monitor the affected pathways over time.
Evoked Measurement of Auditory Sensitivity
John C Watkinson, Raymond W Clarke, Christopher P Aldren, Doris-Eva Bamiou, Raymond W Clarke, Richard M Irving, Haytham Kubba, Shakeel R Saeed in Paediatrics, The Ear, Skull Base, 2018
The ALR can be used clinically to diagnose lesions of the CANS. Patients with lesions of the temporal lobe have been shown to demonstrate prolonged ALR latencies, reduced amplitudes and/or absent potentials.87 The ALR can also be used in the assessment of hearing sensitivity and in auditory rehabilitation applications.88–92 Stimuli of relatively long duration can be used to evoke the response due to the very slow stimulus repetition rate and long time window of the ALR (see below). This allows for an increased number of cycles in pure-tone stimuli, which may yield better frequency specificity of the evoked response in adults.88 The ability to use longer stimuli also allows for the inclusion of more complex sounds, such as speech, in the ALR paradigm.89 The ALR has also been used in rehabilitation contexts for demonstrating that amplification makes sounds audible in infants90 and to show outcomes from auditory training.91,92
After-effect induced by microwave radiation in human electroencephalographic signal: a feasibility study
Published in International Journal of Radiation Biology, 2018
Maie Bachmann, Laura Päeske, Andreas A. Ioannides, Jaanus Lass, Hiie Hinrikus
High amplitude artifacts, generated by repeated electromagnetic stimuli, presents an additional complication in detection of MWR-induced ERP. We hypothesized that for any electromagnetic change in the environment detected by the brain there will be an onset and offset response elicited by the start and end of the stimulation. We, therefore, expect that an evoked potential will be generated in response to the stimulus onset and offset irrespective of whether or not this is consciously perceived. In the case of MWR, there can be no perception as humans do not have an organ to sense MWR. The unambiguous detection of offset effect is significant without any reference to the offset effects from stimuli that are perceived. In this study, we avoided the complications of direct interference of MWR to the EEG sensors by focusing on the detection of an offset effect. The demonstration of offset effects confirms that the presence of MWR induces a change in the brain and that the return to an earlier state after the cessation of MWR leaves a measurable imprint in the EEG record.
Pathobiology of ischiocavernosus and bulbospongiosus muscles in long-term diabetic male rats and its implication on erectile dysfunction
Published in The Aging Male, 2020
Prakash Seppan, Ibrahim Muhammed, Zafar Iqbal Khan Mohammad, Sathya Bharathy Sathyanathan
The initiation and maintenance of penile erection depend on nerve control of the vasculature [25], concurrently, the integrity of the striated muscle system, i.e. ischiocavernosus (IC) and bulbospongiosus (BS) is mandatory for rigid erection. The penile bulb is surrounded by the BS, the penile crura and proximal part of the shaft by the IC [26,27]. The BS arises from the perineal body, and its anterior fibers end in a tendinous expansion, which extends over the dorsal aspect of the penis covering the dorsal vessels [26]. The BS assists in penile erection by compressing the erectile tissue of the penile bulb and the deep dorsal vein of the penis [28]. The IC arises from the ischial tuberosity and ramus, and its fleshy fibers end in an aponeurosis attached to the sides and undersurface of the crus penis [26]. The contractions of muscles on corporal tissue facilitate elevation of intracavernous pressure (ICP) that seems to be a reflex and mediated through the corpus cavernosum, which apparently leads to rigid erection [29]. Changes in the evoked response amplitude would indicate a defect in the reflex pathway. In the rigid erection phase, ICP may increase well above the systolic pressure due to IC and BS muscle contraction [30]. It has been noted that surgical removal of IC and BS leads to ED [31], indicating importance of IC and BS in penile erection.
Transverse myelitis associated with primary biliary cirrhosis: clinical, laboratory, and neuroradiological features
Published in International Journal of Neuroscience, 2022
Mangsuo Zhao, Mingjie Zhang, Shimei Zhou, Bingxin Shi, Yan Wei, Fangjie Huang, Jing Wang, Jingfeng Huang, Liyan Qiao
On laboratory workup, the results of routine blood tests, urine test, stool analysis, and measurements of liver, renal, and thyroid functions, homocysteine, folic acid, and vitamin B12 levels, and the erythrocyte sedimentation rate (ESR) were all within the normal limits. Anti-nuclear (ANA), anti-double-stranded DNA, anti-extractable nuclear antigen, and anti-neutrophil cytoplasmic antibodies were not found in the serum. The results of routine and biochemical tests of the cerebrospinal fluid (CSF) were normal. Oligoclonal bands (OB) were positive. Anti-AQP4 IgG was not detected in serum or CSF. Serum and CSF were negative for the following antibodies: anti-N-methyl-d-aspartic acid receptor, anti-contactin-associated protein-like 2, anti-α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor 1 and 2, anti-leucine-rich glioma-inactivated 1, anti-gamma-aminobutyric acid B receptor, and anti-dipeptidyl-peptidase-like protein 6 for autoimmune encephalitis. As biomarkers of paraneoplastic syndromes, Hu (anti-neuronal nuclear antibody 1), Yo (Purkinje cell autoantibody, PCA1), Ri (anti-neuronal nuclear antibody 2), Ma2, CV2/CRMP5, and amphiphysin were not detected in serum or CSF. Magnetic resonance imaging (MRI) studies of the brain and spinal cord were performed. Abnormal enhancement of the spinal cord was observed at T8–T9, suggestive of incomplete TM (Figure 1). Brain MRI showed no obvious abnormalities. Visual evoked potential and brainstem auditory evoked potential were within the respective normal ranges. The P40 wave of the somatosensory evoked potential disappeared bilaterally.
Related Knowledge Centers
- Animal
- Electrodiagnostic Medicine
- Electroencephalography
- Electromyography
- Electrophysiology
- Nervous System
- Brain
- Stimulus
- Pure Tone
- Stimulus Modality