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Spinal muscular atrophy (SMA) is neuromuscular disorder. This disorder affects motor neurons in anterior horns of spinal cord and brainstem, and cause muscle weakness. Some forms of SMA may be cause by damage peripheral nerve. The most significant difference in the pathology of SMA emerging at the level of the spinal cord and peripheral nerves is deterioration of sensory ability. Decreased ability of sensation, due to damage to sensory nerves. Nowadays, it is known 29 forms of SMA, which differ genetically, age of onset of the disorder, severity of symptoms and life expectancy. Mutation of minor forms of SMA is very diverse. Mutated genes are located on 15 different chromosomes, including the X chromosome. Clinical symptoms of SMA is similar in most forms. Several forms has another symptom besides muscular weakness. Nowadays, it is not yet known genetic cause of all forms of SMA

The process of communication between brain and spinal cord remains unclear. Therefore an attempt supported by spinal cord stereotaxy was made to disclose the physiological mechanism underlying the cooperation between brain and spine as generated by the spinal cord. The initializing stimulus was the discovery of motoneuron location in all spinal cord segments providing the organic substrate for spinal cord stereotaxy. What remained to be clarified were the anatomical structures of spinal cord, participating in the feedback between brain and spinal cord. Therefore two possible hypotheses were proposed by the authors. One is closely related to the analytic-synthetic mechanism of real object and thoughts depiction in the memory of the brain and in the form of concrete ideas forming the basis for concrete thinking. In the case of spinal cord, another more probable mechanism should be considered: The process of analysis and synthesis between the participating spinal motoneurons. The mutual neuronal connections in the spinal cord are capable of depicting the movement pattern and the movement is transferred by means of the described spinal cord pathways to the memory of the brain as a concrete movement idea. From here the ideas are transferred according to the individual needs backwards by means of another described spinal cord pathways back to the spinal cord and the spinal cord is the final effector. The process of thinking is the physiological correlate of technical software, but in the form of abstract thinking it is transferred to the form of abstract thinking.

The occurrence of spasticity is most commonly attributed to the lack of presynaptic inhibition. Perinatal damage to the central nervous system, as it happens in cerebral palsy, leads to pathological reflex response both on segmental and polysegmental levels. It results not only in clinical signs typical for spasticity but also in alterations of brainstem function, such as dysarthria or congenital nystagmus. Selective posterior rhizotomy is a neurosurgical method, routinely used in the treatment of spasticity. The lumbosacral posterior roots are partially cut under perioperative neurophysiological control. The aim of the treatment is the reduction of afferentation for posterior horns resulting in a decrease of pathological reflex responses. Selective posterior rhizotomy consequently decreases lower limbs spasticity. The improvement of upper extremities fine skills, the improvement of speech and cognitive functions has been also observed after selective posterior rhizotomy. The possible pathophysiological explanations of these so-called suprasegmental effects are discussed in the article.

The authors examined evoked motor potentials (MEP) of the upper extremities in a group of 43 patients with multiple sclerosis using transcranial cortical and spinal stimulation. As abnormal they rated a prolongation of the motor conduction time by more than 3 sigma above the mean value recorded in the control group or when the response could not be evoked. The central motor conduction time between the cortex and cervical spine was abnormal in 76.7% of patients. The authors did not find a correlation between the severity of the paresis and the degree of electrophysiological abnormality. In frust and mild pareses the sensitivity was 80%. The frequency of abnormalities correlated with the degree of the diagnostic certainty. In patients with a probable diagnosis (according to Poser) abnormalities were present in 41.6%, when the diagnosis was certain, in 90.3%. In prolongation of the time of central motor conduction among all abnormalities 65.1% were due to prolonged motor conduction and in 27.9% the response could not be evoked. MEP examination is a sensitive technique for the detection of clinical and subclinical lesions and as to its sensitivity it is better than visual EP.

The ulnar nerve's motoric fibre conduction velocity was stated to be insignificantly disordered in 32 patients with syringomyelia, whereas 47 neuropathic patients with unknown etiology showed the disorder mentioned above as occurring by far more frequently and in a more extent. From 6 stimulative indices, those of distal extremities velocity had maximum of deviations. Nevertheless, the indices of longer sections revealed the most numerous pathologic findings, especially in determining forearm velocity. The obtained findings are compared with 233 control subjects.

The disordered velocity was reported in motoric neural fibres to have occurred in 50 traumatic ulnar lesions mainly with wrist disorders, and in 69 compressive lesions with maximum disorders on elbow region. Most pronounced were changes localized distally at the portion which included also the velocity on both the motoric plate and muscle. The maximum pathologic changes were detected on the longer portion studied and mainly on motoric neural ulnar fibres in both groups of the forearm due to the lesser value divergence. As to the traumatic lesions, pathologic changes were more expressed and greater in number than those compressive ones.

The introductory part deals with a great community impact of ulnar nerve damage and its high incidence. From peripheral nerves, this ulnar is the most frequently exposed to injuries and impresses. The impressory damage occurs mainly in elbow region. Anatomic peculiarities of ulnar nerve are scrutinized concerning with more connective tissue presence on its cutting section comparably to the other upper limb nerves. Frequent innervative deviations are referred to especially in ulnar and median nerve regions in the course of ulnar nerve branching. Also three types of anastomoses are listed between the both nerves which are important as to the clinical pattern in damages and for electrophysiologic diagnosing. From the clinical tests, those of rare use are emphasized (test of crossed fingers, palmaris brevis sign, Mumenthaler's sign, ulnar test). The last part deals in detail with anatomic, functional and clinical problems of ulnar nerve in elbow area. Its biomechanic relations in the cubital tunnel are elucidated as well as etiopathogenetic factors of neural damage in this area (traction and compressive theories and hypermobility of the nerve etc.). The most frequent causes of ulnar injuries are reviewed. The present work is of introductory value for those dealing mainly with electrophysiologic problems of both sensitive and motoric neural injuries varying in the intensity, location and diagnosis.