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Electrophysiologic Data (electrophysiologic + data)
Selected AbstractsBiting Behavior, Aggression, and SeizuresEPILEPSIA, Issue 5 2005Carlo Alberto Tassinari Summary:,Purpose: To describe the semiologic features of aggressive behaviors observed in human epileptic seizures with particular reference to the act of biting a conspecific. Methods: We analyzed the biting behavior (BB) and other aggressive gestures occurring in a group of 11 patients retrospectively selected from >1,000 patients subjected to video-EEG/SEEG monitoring for presurgical evaluation of drug-resistant seizures. Results: Patients displaying BB showed (a) a male sex predominance, (b) heterogeneous etiologies and lesion locations, and (c) seizures involving the frontotemporal regions of both hemispheres. The act of biting was a rapid motor action, lasting ,600 ms, occurring in the context of strong emotional arousal, fear, and anger, with various bodily gestures with aggressive connotation. BB was mainly a "reflexive" behavior, in that biting acts were evoked (both during and after seizures) by actions of people in close contact with the patient. The sole intrusion of the examiner's hand in the space near the patient's face was effective in triggering BB. Rarely, self-directed or object-directed biting acts were not triggered by external stimuli. Intracranial data (SEEG) obtained in one subject showed that the amygdala/hippocampal region plus the orbitomedial prefrontal cortex had to be involved by ictal activity to observe BB. Conclusions: Anatomic and electrophysiologic data in our patients suggest that a model of dual,temporal and frontal,dysfunction could account for the occurrence of ictal/postictal BB. Behavioral data suggest also that BB and related aggressive gestures can be considered as the emergence of instinctive behaviors with an adaptative significance of defense of the peripersonal space. [source] Utility of the distal compound muscle action potential duration for diagnosis of demyelinating neuropathiesJOURNAL OF THE PERIPHERAL NERVOUS SYSTEM, Issue 3 2009Sagiri Isose Abstract To assess the significance of distal compound muscle action potential (CMAP) duration for diagnosis of demyelinating neuropathies, electrophysiologic data were reviewed from 471 subjects, including 145 normal controls, 60 patients with chronic inflammatory demyelinating polyneuropathy (CIDP), 205 with other neuropathy, and 61 with amyotrophic lateral sclerosis (ALS). The duration of distally evoked CMAP was measured in the median, ulnar, tibial, and peroneal nerves. Optimal cut-off values were calculated with receiver-operating characteristic (ROC) curves. In comparison of normal controls and CIDP patients, ROC analyses showed the sufficient area under the curves (82-93%). When the cut-off values in the detection of demyelination were determined as the point with 98% specificity vs. normal on the ROC curves (median, 6.6 ms; ulnar, 6.7 ms; peroneal, 7.6 ms; tibial, 8.8 ms), the sensitivity was 77% for CIDP, with a specificity of 90% vs. ALS and 95% vs. diabetic neuropathy. The distal CMAP duration is a useful index for the detection of distal demyelination. We suggest the above cut-off values for each nerve as one of the electrodiagnostic criteria for demyelinating neuropathies, preferentially affecting the distal nerve terminals, such as CIDP. [source] Reverse Electrical Remodeling of the Atria Post Cardioversion in Patients Who Remain in Sinus Rhythm Assessed by Signal Averaging of the P-WavePACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 4 2007NAGIB CHALFOUN M.D. Objectives: This study was designed to determine whether the signal-averaged electrocardiogram of the P-wave (SAPW) is an independent predictor of recurrence of atrial fibrillation (AF) post cardioversion (CV), and to assess atrial remodeling using SAPW. Background: There are limited electrophysiologic data to predict the recurrence of AF post-CV. The electrical remodeling that occurs post-CV is poorly understood. Methods: Sixty-four patients with persistent AF undergoing CV were prospectively enrolled. SAPW parameters were measured the day of CV and repeated at 1 month. These SAPW parameters were compared to other baseline indices for the recurrence of AF. Results: Sixty patients (94%) had successful CV. At 1 month, 22 (37%) maintained sinus rhythm (SR). The SAPW total duration decreased significantly in those who remained in SR (159 ms ± 19 to 146 ms ± 17; P < 0.0001). Only the duration of AF (46 ± 50 days vs 147 ± 227 days, P = 0.03) and the presence of left ventricular hypertrophy (LVH, 12% vs 65%, P = 0.0006) were significantly associated with recurrence of AF. Atrial size strongly correlated with the SAPW duration in patients who remained in SR (R2= 0.67, P = 0.003) but not in those who returned to AF (R2= 0.11, P = 0.65). Conclusions: Atrial electrical reverse remodeling occurs in patients with AF who maintain SR post-CV. This remodeling is likely inversely related to the duration of AF and LVH. SAPW duration does not predict recurrence of AF post-CV. [source] A novel recessive Nefl mutation causes a severe, early-onset axonal neuropathy,ANNALS OF NEUROLOGY, Issue 6 2009Sabrina W. Yum MD Objective To report the first cases of a homozygous recessive mutation in NEFL, the gene that encodes the light subunit of neurofilaments. Methods Clinical and electrophysiologic data were evaluated, and a sural nerve biopsy from one affected child was examined by immunohistochemistry and electron microscopy. The ability of the mutant protein to form filaments was characterized in an established cell culture system. Results Four of five siblings developed of a severe, progressive neuropathy beginning in early childhood. Serial nerve conduction studies showed progressively reduced amplitudes with age and pronounced slowing at all ages. Visual-evoked responses were slowed in three children, indicating that central nervous system axons were subclinically involved. All four affected children were homozygous for a nonsense mutation at glutamate 210 (E210X) in the NEFL gene; both parents were heterozygous carriers. A sural nerve biopsy from an affected patient showed markedly reduced numbers of myelinated axons; the remaining myelinated axons were small and lacked intermediate filaments. The E210X mutant protein did not form an intermediate filament network and did not interfere with the filament formation by wild-type human light subunit of neurofilaments in SW-13 vim, cells. Interpretation This is the first demonstration of a recessive NEFL mutation, which appears to cause a simple loss of function, resulting in a severe, early-onset axonal neuropathy with unique features. These results confirm that neurofilaments are the main determinant of axonal caliber and conduction velocity, and demonstrate for the first time that neurofilaments are required for the maintenance of myelinated peripheral nervous system axons. Ann Neurol 2009;66:759,770 [source] Glutamate levels and activity of the T cell voltage-gated potassium Kv1.3 channel in patients with systemic lupus erythematosusARTHRITIS & RHEUMATISM, Issue 5 2008C. Poulopoulou Objective Alterations in glutamate homeostasis and Kv1.3 voltage-gated potassium channel function have been independently associated with T cell dysfunction, whereas selective blockade of Kv1.3 channels inhibits T cell activation and improves T cell,mediated manifestations in animal models of autoimmunity. Because low extracellular glutamate concentrations enhance the activity of this channel in normal T cells ex vivo, we undertook this study to examine serum glutamate concentrations and Kv1.3 channel activity in patients with systemic lupus erythematosus (SLE). Methods We used high-performance liquid chromatography for glutamate measurements, and we used the whole-cell patch-clamp technique for electrophysiologic studies performed in freshly isolated, noncultured peripheral T cells. Results Mean ± SD serum concentrations of glutamate were lower in patients with either clinically quiescent SLE (77 ± 27 ,M [n = 18]) or active SLE (61 ± 36 ,M [n = 16]) than in healthy controls (166 ± 64 ,M [n = 24]) (both P < 0.0001). The intrinsic gating properties of the Kv1.3 channels in lupus T cells were found to be comparable with those in healthy control,derived T cells. Notably, electrophysiologic data from SLE patient,derived T cells exposed to extracellular glutamate concentrations similar to their respective serum levels (50 ,M) demonstrated Kv1.3 current responses enhanced by almost 20% (P < 0.01) compared with those subsequently obtained from the same cell in the presence of glutamate concentrations within control serum levels (200 ,M). Conclusion Based on the key role of Kv1.3 channel activity in lymphocyte physiology, an enhancing in vivo effect of low serum glutamate concentrations on the functional activity of this channel may contribute to lupus T cell hyperactivity. Studies to further elucidate Kv1.3 responses in SLE, as well as the possible pathogenetic role of this unsuspected metabolic abnormality, may have therapeutic implications for SLE patients. [source] | ||||||||||