Vliv Valsalvova manévru zadrženéhovýdechu na mechanismus vznikuporuchy řeči u koktavého

The Influence of the Valsalve Maneuver of Retained Expiration on the Mechanism ofthe Origin of Speech Disorder in a Stutterers

Stuttering is a serious disorder of speechfl uency. The manifestations includea superfluous increase of muscular tension, which originates not only on vocal cords, but may begeneralized into skeletal muscles of the whole body and become manifest even by clonic spasms.Some authors are of the opinion that increased tension of laryngealmuscles, leading to the occlusionof glottis, corresponds to the mechanism of Valsalve maneuver, which participates in the developmentof the stuttering. The opinion was coined by Perry, who had suffered from stuttering from hischildhood and was treated with various procedures without success. He elaborated, and claimed tohave experienced himself the method for the treatment of stuttering, which evokes fluent speechby suppressing the mechanisms of the Valsalve maneuver. The method is based on suppressing theactivity of abdominal and thoracic muscles, which brings about a soft beginning, while practice ofspeechena ble to bind individual words and syllables. In a clinical examination of the stutteringpatient withtonic manifestations in the speechres ulting even into long initial tones and speechblocks clearly indicates that the mechanism of the Valsalve maneuver indeed becomes manifestduring the stuttering attack.We therefore decided tomake an objective study of the influence of theValsalve experiment on the motor activities by determining the effects of the Valsalve maneuver onmono-synaptic reflex activity of spinal cord in the S1 segment by means of electrically evokedmono-synaptic reflex of spinal cord (Hoffmann’s reflex, so called H-reflex). The amplitude of theH-reflex was followed at rest as well as in the course of the Valsalve maneuver. It became obviousthat the H-reflex amplitude increased during the Valsalve experiment, the increase being statisticallysignificant at 5% probability level. The increase of H-reflex amplitude in the course of theValsalve maneuver is apparently due to increased flow of afferent impulses as a consequence ofgeneralized increase in muscular tension and muscular strain, which is the basis of the Valsalvemaneuver. This increased afferentation then follows to increased excitability of motor cells at thespinal and supraspinal level. This kind of increased excitability then makes it possible to maintaina high level of muscular tonus, which follows to improved muscular strength, consequently toquantitative improvement of motor effectiveness. At the same time this increase deterioratesa precise coordination of minute motions, and consequently the qualitative aspect of fine motoractivity, which is under great demands especially during motor realization of speech. The mechanismsof the Valsalve maneuver therefore clearly participate in the evolution of stuttering attack,although they are neither the cause nor decisive. An increased excitability of motor system anddecreased fine motor activity is muchmore pronounced as a consequence of spreading negativeemotion, which originates during the stuttering attack and influences the reflex motor activity morethan the Valsalve maneuver. The principles of therapeutic procedure based on intentional suppressionof themechanism of the Valsalve maneuver may have favorable results, though.A more detailedanalysis of the therapeutic method, as recommended by its supporters, indicate many common features shared with other methods. In particular, the principles are similar to a series of otherprocedures including the Seemans method of complex traetment of stuttering.

Key words:
Valsalve maneuver, fluent speech, respiratory pathways, muscular activity.