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Difference between revisions of "Encrypted code: Bilateral Motor Evoked Potentials of trigeminal root"
Encrypted code: Bilateral Motor Evoked Potentials of trigeminal root (view source)
Revision as of 11:28, 23 April 2023
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(Created page with "{{Versions | en = Encrypted code: Bilateral Motor Evoked Potentials of trigeminal root | it = Codice criptato: Potenziali Evocati Motori Bilaterali della radice trigeminale | fr = 'Code crypté : Potentiels évoqués moteurs bilatéraux de la racine du trijumeau' | de = 'Verschlüsselter Code: Bilaterale motorisch evozierte Potenziale der Trigeminuswurzel' | es = 'Código cifrado: Potenciales evocados motores bilaterales de la raíz del trigémino' | pt = <!--...") |
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The subject was asked to clench his teeth to produce maximal EMG activity and to maintain the contraction for at least 3 s, with the help of visual and audio feedback. After 60 seconds of rest, the subject repeated the contraction 10 times. The EMG signal was recorded in directly rectified and averaged mode. The placement of the recording electrodes was the same as that used to record the jaw jerk and the preamplifier parameters are set to a time window width of 500ms, 200mV per division and a filter bandwidth of 50-1kHz. The latencies and durations of the SPs and the AI (Figure 1) were calculated as follows: | The subject was asked to clench his teeth to produce maximal EMG activity and to maintain the contraction for at least 3 s, with the help of visual and audio feedback. After 60 seconds of rest, the subject repeated the contraction 10 times. The EMG signal was recorded in directly rectified and averaged mode. The placement of the recording electrodes was the same as that used to record the jaw jerk and the preamplifier parameters are set to a time window width of 500ms, 200mV per division and a filter bandwidth of 50-1kHz. The latencies and durations of the SPs and the AI (Figure 1) were calculated as follows: | ||
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[[File:Meningioma 3 by Gianni Frisardi.jpg|center|thumb|'''Figura 1:''' Ciclo di recupero del Riflesso Massetere Inibitorio (rcMIR)]] | [[File:Meningioma 3 by Gianni Frisardi.jpg|center|thumb|'''Figura 1:''' Ciclo di recupero del Riflesso Massetere Inibitorio (rcMIR)]] | ||
<blockquote> | <blockquote> | ||
To simplify the examination, the rcMIR was evoked by electrically stimulating the left side only. The EMG responses correspond to the EMG tracings of the right masseter (Ch1) and left masseter (Ch2). Thus, on the traces, each marker indicates the channel number, while the letters indicate the sequences of latencies. | |||
*The S1 stimulus splits the acquisition into pre and post analysis and generates the SPs and the AI. | *The S1 stimulus splits the acquisition into pre and post analysis and generates the SPs and the AI. | ||
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</blockquote> | </blockquote> | ||
In the tested subject the S2 stimulus was able to evoke both SPs, while in a normal subject the S2 stimulus is normally able to evoke only the SP1 or at most one SP2 of reduced duration. As shown in Table 2, the duration of S2-evoked SP1 was found to be very stable, with no significant differences in the duration of S1-generated SP1 (Δ= -1ms for Ch1 and Δ= -2 ms for Ch2) while the from S2 on the right and left masseter (61 ms and 54 ms, respectively) was longer than that evoked by S1 (39 ms and 35 ms, respectively). The differences were +22 ms for Ch1 (right masseter) and +19 ms for Ch2 (left masseter). Consequently, the duration of the AI showed clear differences between S2 and S1. The duration of the S2-evoked AI was 12 ms vs. 23 ms of S1 stimulus for the right masseter (Ch1) and 17 ms vs 30 ms of S1 for the left masseter (Ch2) with a difference between the responses evoked by S2 minus S1 of -11 ms and -13 ms, respectively. | In the tested subject the S2 stimulus was able to evoke both SPs, while in a normal subject the S2 stimulus is normally able to evoke only the SP1 or at most one SP2 of reduced duration. As shown in Table 2, the duration of S2-evoked SP1 was found to be very stable, with no significant differences in the duration of S1-generated SP1 (Δ= -1ms for Ch1 and Δ= -2 ms for Ch2) while the from S2 on the right and left masseter (61 ms and 54 ms, respectively) was longer than that evoked by S1 (39 ms and 35 ms, respectively). The differences were +22 ms for Ch1 (right masseter) and +19 ms for Ch2 (left masseter). Consequently, the duration of the AI showed clear differences between S2 and S1. The duration of the S2-evoked AI was 12 ms vs. 23 ms of S1 stimulus for the right masseter (Ch1) and 17 ms vs 30 ms of S1 for the left masseter (Ch2) with a difference between the responses evoked by S2 minus S1 of -11 ms and -13 ms, respectively. | ||
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<gallery widths="340" heights="300" perrow="2" slideshow""=""> | <gallery widths="340" heights="300" perrow="2" slideshow""=""> | ||
File:Meningioma 3 by Gianni Frisardi.jpg | File:Meningioma 3 by Gianni Frisardi.jpg | ||
File:Meningioma 2 by Gianni Frisardi.jpg | File:Meningioma 2 by Gianni Frisardi.jpg | ||
File:Meningioma 4 by Gianni Frisardi.jpg | File:Meningioma 4 by Gianni Frisardi.jpg | ||
File:Meningioma 5 by Gianni Frisardi.jpg | |||
</gallery> | </gallery> | ||
</Center> | |||
{{Q2|The test showed a high speed of recovery of the synaptic responses of the trigeminal system, index of neuronal hyperexcitability. This led the clinician to urgently request an MRI of the brain to define the correct diagnosis.}} | |||
====3rd Step: brain MNR==== | ====3rd Step: brain MNR==== | ||