Chronic Intractable Epilepsy as the Only Symptom of Primary Brain Tumor

We identified 39 patients with chronic epilepsy (seizures ≥2 years) proven to have primary brain tumors. These cases represent ～12% of the surgery cases for epilepsy in the same period. Mean age of seizure onset was 13.2 years: mean duration before operation was 10.5 years. Thirty-eight of 39 had normal neurologic examination. Twenty-six tumors were temporal, 7 were frontal, 4 were parietal, and 2 were occipital. Nine of 26 (34.6%) of the temporal group had contralateral interictal EEG spikes. Pathology was 15 ganglioglioma, 13 low-grade astrocytoma, 4 oligodendroglioma, 2 low-grade mixed glioma, 1 pleomorphic xanthoastrocytoma, 2 dysembryoplastic neuroepithelial tumor, and 1 ependymoma. Postoperative seizure frequency (minimum follow-up 6 months) ranged from 15 to 16 seizure-free or auras only in patients with temporal tumors and total gross tumor removal (mean follow-up 28 months) to 0 of 6 seizure-free in patients with extratemporal tumors who underwent subtotal resections or biopsy.     

Effects of hemodialytic treatment on uremic polyneuropathy

Summary The involvement of the peripheral motor and sensory nerve, at least on a subclinical level, is a nearly constant event with chronic renal failure. The study of the motor and sensory propagation velocity indicates that a widespread functional lesion of the axon with a peripheral point of attack and secondary demyelination, may be the basic pathogenetic event of uremic polyneuropathy. Prolonged hemodialytic treatment is substantially unable to influence the evolution of uremic polyneuropathy. The electrophysiological follow-up study of the peripheral nerve does not seem to be an index of adequate dialysis.

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Zusammenfassung Die Beteiligung des peripheren motorischen und sensiblen Nerven, zumindest subklinisch, ist bei chronischer Niereninsuffizienz Regel. Die Untersuchung der motorischen und sensorischen Erregungsleitungsgeschwindigkeit spricht dafür, daß bei der urämischen Polyneuropathie als wesentliches pathologisches Geschehen das Axon besonders distal ausgedehnt betroffen ist mit einer sekundären Demyelinisation. Auch langdauernde Hämodialyse scheint nicht in der Lage zu sein, die Entwicklung der urämischen Polyneuropathie zu beeinflussen. Die elektrophysiologische fortlaufende Kontrolle des peripheren Nerven scheint nicht ein brauchbarer Parameter für eine wirksame Dialyse zu sein.

     

Interexaminer repeatability of antidromic ulnar sensory nerve conduction velocity measurements

OBJECTIVE: To determine the interexaminer repeatability of the ulnar antidromic sensory nerve conduction velocity (NCV). DESIGN: Test-retest design. Based on a randomization list of various combinations and sequences from 2 of a total of 3 examiners, the measurement was repeated within half an hour by a second examiner blinded to the results of the first examiner. SETTING: Outpatient department. PARTICIPANTS: Twenty-four consecutive healthy subjects (mean age, 38 y). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: The intraclass correlation coefficient (ICC) and the coefficient of repeatability (CR) were determined for the below elbow to wrist (BE-to-W), above elbow to below elbow (AE-to-BE), and axilla to above elbow (AX-to-AE) segments. RESULTS: The ICC was .42 for the BE-to-W, .15 for the AE-to-BE, and -.05 for the AX-to-AE segment. The CR was 12.2m/s for the BE-to-W, 16.2m/s for the AE-to-BE, and 21.4m/s for the AX-to-AE segment. CONCLUSIONS: During the assessment of the antidromic sensory NCV of the ulnar nerve, a moderate amount of interexaminer variability must be taken into account for the BE-to-W segment. More proximally, an extremely large amount of interexaminer variability must be taken into account. This calls into question the usefulness of the antidromic ulnar sensory NCV for the AX-to-AE and AE-to-BE segments.     

Normal and abnormal face selectivity of the M170 response in developmental prosopagnosics

Developmental prosopagnosia is a lifelong impairment in face recognition despite normal low-level visual processing. Here we used magnetoencephalography (MEG) to examine the M170 response, a component occurring approximately 170 ms after stimulus onset, in a group of five developmental prosopagnosics. In normal subjects, the M170 is “face-selective”, with a consistently higher amplitude to faces than to a wide variety of other visual stimulus categories; the N170, a component recorded using event-related potentials (ERP) and thought to be analogous to the M170, also shows this “face selectivity”. Two previous ERP studies with developmental prosopagnosics have found attenuation or absence of face selectivity in the N170 response of these subjects [Bentin, S., Deouell, L. Y., & Soroker, N. (1999). Selective visual streaming in face recognition: Evidence from developmental prosopagnosia. Neuroreport, 10, 823–827; Kress, T., & Daum, I. (2003). Event-related potentials reflect impaired face recognition in patients with congenital prosopagnosia. Neuroscience Letters, 352, 133–136]. Three of our developmental prosopagnosic group showed this non-selective pattern at the M170 while the remaining two prosopagnosics were indistinguishable from normal controls. Thus, impaired face recognition is not necessarily correlated with an absence of the “face-selective” M170. Furthermore, ERP recordings collected simultaneously in the two developmental prosopagnosics with seemingly selective M170s also showed N170s within the same normal selective range, demonstrating that the face-selective signals found with MEG are not due to differences between MEG and ERP. While the presence of face selectivity at these neurophysiological markers is insufficient for predicting normal behavioral performance with faces, it could help to distinguish different classes of face recognition deficits.     

Neurophysiology of micturition and continence in women

Micturition and continence involve the coordination of complex neural events between the central and peripheral nervous systems. An understanding of these events provides a foundation for the treatment of voiding disorders in women such as stress urinary incontinence, urge incontinence and interstitial cystitis. The purpose of this paper is to comprehensively review the neuroanatomy, enurophysiology and neuropharmacology of micturition and continence. However, a brief section discussing clinical correlations will follow each of these topics to help integrate the basic science with clinical obervations.     

Hypoesthesia after anterior cruciate ligament reconstruction: The relationship between proprioception and vibration perception deficits in individuals greater than one year post-surgery

Background

While surgical reconstruction restores mechanical stability following anterior cruciate ligament (ACL) rupture, many experience early-onset osteoarthritis despite surgery. Neurophysiological changes are hypothesized to contribute to knee osteoarthritis progression. Proprioceptive deficits have been reported following ACL injury/reconstruction; however, vibration perception threshold (VPT) has been less studied. This study explored relationships between pain, VPT, proprioception, function, and strength following ACL-reconstruction.

人体针刺操作实践对手指精细触觉的影响

目的:研究人体针刺操作实践对手指精细触觉敏感度的影响,以深入认识操作者的得气感知过程,挖掘影响得气感判断能力的关键因素。方法:运用皮肤感觉阈和两点辨别阈等精细触觉测试指标,测试15名针灸执业医师双手拇指、食指及中指的皮肤精细触觉,并与15名普通人进行对照,分析针灸医师与普通人的精细触觉差异。结果:针灸医师押手的皮肤感觉阈和两点辨别阈与普通人非利手相近,而针灸医师刺手的皮肤感觉阈和两点辨别阈与普通人利手相比均有降低趋势,尤其以食指更为明显。结论:手指皮肤精细触觉是影响得气感知能力的关键因素,长期人体针刺操作实践可以适应性提高操作者持针手指皮肤精细触觉的敏感度。     

A systematic review of the neurophysiology of mindfulness on EEG oscillations

Mindfulness meditation has been purported to be a beneficial practice for wellbeing. It would therefore be expected that the neurophysiology of mindfulness would reflect this impact on wellbeing. However, investigations of the effects of mindfulness have generated mixed reports of increases, decreases, as well as no differences in EEG oscillations in comparison with a resting state and a variety of tasks. We have performed a systematic review of EEG studies of mindfulness meditation in order to determine any common effects and to identify factors which may impact on the effects. Databases were reviewed from 1966 to August 2015. Eligibility criteria included empirical quantitative analyses of mindfulness meditation practice and EEG measurements acquired in relation to practice. A total of 56 papers met the eligibility criteria and were included in the systematic review, consisting of a total 1715 subjects: 1358 healthy individuals and 357 individuals with psychiatric diagnoses. Studies were principally examined for power outcomes in each bandwidth, in particular the power differentials between mindfulness and a control state, as well as outcomes relating to hemispheric asymmetry and event-related potentials. The systematic review revealed that mindfulness was most commonly associated with enhanced alpha and theta power as compared to an eyes closed resting state, although such outcomes were not uniformly reported. No consistent patterns were observed with respect to beta, delta and gamma bandwidths. In summary, mindfulness is associated with increased alpha and theta power in both healthy individuals and in patient groups. This co-presence of elevated alpha and theta may signify a state of relaxed alertness which is conducive to mental health.     

Evoked potentials predict psychomotor development in neonates with normal MRI after hypothermia for hypoxic-ischemic encephalopathy

Objectives

To assess the prognostic role of evoked potentials (EP) in neonates with normal magnetic resonance imaging (MRI) after therapeutic hypothermia (TH) for hypoxic-ischemic encephalopathy (HIE).

Thyrotropin-releasing hormone has profound presynaptic action on cultured spinal cord neurons

Thyrotropin-releasing hormone (TRH) receptors are widely distributed throughout the nervous system. In particular, both the dorsal and the ventral horn (VH) neurons contain a rich distribution of TRH receptors, and TRH application to these sites has profound physiological effects. Currently the mechanism of action of TRH is not known. We examined the effect of TRH on ventral horn neurons using intracellular and patch-clamp techniques. Our results indicate that TRH application profoundly increases the firing rate of VH cells by decreasing membrane conductance. More importantly, TRH causes a significant increase in frequency and amplitude of postsynaptic potentials. Under voltage-clamp condition, TRH reduces holding current and causes a significant increase in the rate of occurrence and the amplitude of excitatory postsynaptic currents (EPSCs), an effect that lasts for more than 5 minutes. This effect of TRH is not observed in cultured neurons pretreated with tetanus toxin. TRH also fails to alter the characteristics of the EPSCs when it is applied to a region of the cell that is sparsely innervated. These results provide strong evidence that presynaptic mechanisms have a significant role in the excitatory effect of TRH on the VH neurons. Because there is evidence that trophic factors are released from presynaptic terminals, by increasing synaptic activity, TRH can have a trophic influence on the spinal cord neurons. In addition, because there are a significant number of TRH containing neurons within the spinal cord, it is likely that TRH has a major role in information processing within the spinal cord.