Sensibilidade vibratória: valor semiótico em algumas afecções do sistema nervoso

[摘要] The author studies the significance of the accurate test of vibration sense for the diagnosis of some diseases of the nervous system. This work is divided into three main parts. First part - After reviewing the medical literature on the nature, pathways and physiopathology of the vibration sense, the author states the following conclusions : 1. Pallesthesia is an inespecific type of sensation. 2. The receptors for vibratory stimuli include both the superficial structures designed to record the cutaneous deformation, and the end-organs located in the muscles, ligaments, joints and periosteum. 3. On the light of more recent experimental work, carried on by neuro-physiologists and clinical neurologists, it becomes evident that the muscle spindles are the end-organs mostly concerned in the reception of vibratory stimuli. 4. These facts lead to the conclusion that vibration sense impulses run in the spinal cord by tactile and proprioceptive pathways. There are reasons to believe that lesions of the dorsal funiculi are more apt to interfere with the conduction of vibratory stimuli. 5. The dissociation between pallesthesia (lost or impaired) and joint sense (impaired or normal), frequently met with in several nervous diseases, must be ascribed to the fact that injury of nerve fibers lengthens the refractory period; the vibratory stimuli, which normally are transmitted almost in the limit of nerve fiber ability, are thus summed up and does not evoke the vibratory sensation any more. 6. The prevalence of kinesthesic over pallesthesic disturbances, which is said to occur in lesions of parietal lobes, can be explained by the discriminative character of the former type of sensation, as well as by a wider bilateral cortical representation of the vibration sense pathways. Second part - The analysis of variance of the vibratory perception thresholds measured with the "Bio-thesiometer" in 55 normal subjects lead the author to the following conclusions: