Author/Editor		Liščić, RM; Zidar, J
Title		Functional organisation of the facial motor system in man
Type		članek
Source		Coll Antropol
Vol. and No.		Letnik 22, št. 2
Publication year		1998
Volume		str. 545-550
Language		eng
Abstract		To investigate human corticobulbar projections, electromyographic responses from obicularis oculi and orbicularis oris muscles were recorded in 11 healthy subjects after transcranial magnetic stimulaton. Selective activation of lower facial motoneurones of one hemisphere was reached with the round coil 4 cm lateral to the vertex on a line to the external auditory meatus with stimulus intensities from 45 to 55% (100% = 1.5 T). The mean latency of the OR muscle was 11.5 +- 1.77 ms contralaterlly. Ipsilateral cortical responses were observed in 5 subjects (45%) at a mean latency of 13.88 +- 2.17 ms. Corticobulbar innervation may have affected bilateral responses in the lower facial muscles as those persisted even after lidocaine blockade of both supraorbital nerves. The functional importance of ipisilater projections to the lower facial muscles in man is lower than that of the contralateral projections, as evidence by the fact that they cannot be observed in all subjects or in all motor units. The influence of the trigeminal sensory afferents was excluded from the study after blockade of both supraorbital nerves.
Descriptors		FACIAL MUSCLES ELECTROMYOGRAPHY ADULT ELECTRIC STIMULATION ELECTROMAGNETIC FIELDS MOTOR CORTEX NERVE BLOCK NEURAL PATHWAYS SKIN