Difference between revisions of "1° Caso clínico: Espasmo hemimasticatorio"

=== Ephaptic transmission ===

With a little effort and patience on the part of passionate readers who have followed the entire logical path, sometimes apparently off topic, we have reached a clinical picture in which the code to be decrypted is inherent in neuromotor damage. Consequently, the access keys to the code, the one that figuratively corresponds to the exact decryption algorithm, would correspond to the right choice of the neuromotor damage detector test.   

This is a point where it is essential to infer the clinician's intuition because finding the right algorithm to decrypt the code, after the aforementioned filter steps that have been described to wash away the interference of assertions, means at least choosing the right dictionary, for example, that of the image (MR of the brain rather than the neck); acoustic and vestibular evoked potentials (if a vestibular scwannoma is suspected) or trigeminal electrophysiological study (if more than one trigeminal involvement is suspected).

In this clinical iter that we have presented, the choice of the clinician to follow the electrophysiological trigeminal roadmap from which the positivity of the <math>\bar{\gamma_n}=1</math> assertions have already been derived, therefore, having already defined a picture of serious anomaly of absence of the jaw jerk and of the silent period masseterino on the right side of the patient will have to understand if the damage is intracranial or extracranial.

To do this, the clinician uses an electrical stimulation test of the masseter nerve in infratemporal fossa called <math>M-wave</math> on the masseter muscle with simultaneous recording of the heteronymous <math>H-wave</math> on the temporal muscle<ref>{{cita libro  

  }}</ref> and a bilateral transcranial electrical stimulation of the trigeminal motor roots called, precisely, <math>_bRoot-MEPs</math><ref name="fris1992">{{cita libro  

The right masseter nerve was electrically stimulated in the infratemporal fossa (see clinical procedure chapter: [[Encrypted code: Ephaptic transmission]]) with a technique similar to that described by Macaluso & De Laat (1995).<ref>Macaluso G, De Laat A. [https://pubmed.ncbi.nlm.nih.gov/8773249/ H-reflexes in masseter and temporalis muscle in man. Experimental] Brain Research. 1995;107:315–320. [PubMed] [Google Scholar] [Ref list]</ref> Square cathode pulses (0.1 ms) generated by an electrical stimulator (Neuropack X1, Nihon Kohden Corporation, Tokyo, Japan) were delivered through a Teflon-coated monopolar needle electrode (TECA 902-DMG25, 53534) with a tip non-isolated (diameter 0.36 mm; area 0.28 mm2) inserted 1.5 cm through the skin below the zygomatic arch and anterior to the temporomandibular joint in the infratemporal fossa with electrical shocks of 0.5 - 5 mA, and 0.1 ms. The anode was a surface non-polarizable Ag-AgCl disc electrode (OD 9.0 mm) positioned over the ipsilateral ear lobe. Electrical stimulation of the masseter nerve never produced pain, and the subjects only perceived muscle contraction. The correct position of the stimulation electrodes was monitored throughout the experimental session by checking online the size of the M wave in the masseter muscle. The signals were recorded by placing surface electrodes on the masseter and temporal muscles and filtered at 10-2000Hz and by concentric needle electrodes inserted into the anterior temporal muscle.   

{{Q2|The response in the right masseter was clearly delayed but relatively symmetrical in amplitude between sides. (Fig. 9)}}