Unit:
Κατεύθυνση Κλινική ΝευροφυσιολογίαLibrary of the School of Health Sciences
Author:
Tzanos Ioannis-Alexandros
Supervisors info:
Χρόνη Ελισάβετ, Καθηγήτρια, Τμήμα Ιατρικής, Πανεπιστήμιο Πατρών, Επιβλέπουσα
Ζαμπέλης Θωμάς, Αναπληρωτής Καθηγητής, Τμήμα Ιατρικής, ΕΚΠΑ
Στεφανής Λεωνίδας, Καθηγητής, Τμήμα Ιατρικής, ΕΚΠΑ
Original Title:
F-ταχεοδιασπορά ωλενίου και περονιαίου νεύρου σε άπω και εγγύς ερεθισμό
Translated title:
F-chronodispersion of ulnar and peroneal nerve in distal and proximal stimulation
Summary:
It is a general understanding that F - waves of shorter latency are generated by fast conducting large neurons, while those of longer latency by slow conducting small neurons. This view has been questioned by researchers who proposed that latency difference (F - chronodispersion) could be as well explained by unequal delayed along the distal neural branches depending on the distance of each motor unit from the recording electrode. To clarify this issue, we recorded F - waves from a distal and a proximal site of the same nerve. The classical view will be justified if F - chronodispersion is lower at proximal stimulation, where conduction along shorter distances is estimated.
Ten healthy subjects (aged 27.6 ± 4.1, 5 females) were volunteered. Forty consecutive stimuli were applied to the ulnar nerve at the wrist and elbow and to the peroneal at the ankle and knee. F - wave latency minimum and maximum (Flatmin, Flatmax) were measured and corresponding conduction velocities (FCVs) were estimated by the formula: FCVx= (2*Distance / Flatmin - Mlat - 1) *[(Flatmin - 1)/(Flatx - 1)], where x=each F - wave.
Results: For the ulnar nerve, F - chronodispersion, i.e. Flatmax - Flatmin, was significantly shorter at the elbow (mean±sd 2.5±0.7) as opposed to the wrist (3.8±1.0 paired t-test, p= 0.003); likewise for the peroneal nerve, F - chronodispersion was shorter at the knee (3.7±1.7) vs the ankle (5.2±2.0 p=0.003). FCV range was relative shorter along elbow - spinal cord (sc) segment (7.3±2.5; group limits of FCVs: 56-76m/s) vs wrist - sc (9.1±2.7, p=0.06; 54-72); similarly shorter along knee - sc (4.3±1.9; 40-52m/s) vs ankle - sc (5.3±2.2, p=0.05; 38-50m/s).
Our findings showed that F - chronodispersion value depends on the stimulation site, being lower at proximal stimulation. It is a reliable measure of motor neuron conduction properties. Moreover, FCVs, like M-response estimated CVs, where faster along proximal parts.
Main subject category:
Health Sciences
Keywords:
F-chronodispersion, Ulnar nerve, Peroneal nerve, Latency, Stimulation
