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The late potential analysis was performed in 86 neurologically healthy subjects aged 0 month to 6 years. The following muscles were analyzed: soleus, flexor hallucis brevis, extensor digitorum brevis and abductor pollicis brevis muscle. Late potentials were evaluated according to H, HF, F and Ms (missing potentials) attributes. The potential population in a particular muscle in an age group was considered as 100%; the type frequency for a particular muscle in different age groups is presented as absolute value and percentage. No age specific combination was found. As no age specificity was recorded, attempts were made to differentiate the muscle specificity potential type distribution. The mean (x) of potential type percentages of all age groups in the same muscle was calculated. Thus, in soleus muscle, the following response types were found: 29% H-reflex, 15% HF potentials, 45% F-waves and 11% Ms potentials. Flexor hallucis brevis muscles had: 3% H-reflex, 6% HF potentials, 85% F-waves and 6% Ms potentials. In extensor digitorum brevis, not a single H-reflex or HF potential was found, whereas F-waves were observed in 46% and Ms in 54%. Abductor pollicis brevis produced 1% H-reflex, 2% HF, 66% F-waves and 31% Ms potentials. Therefore, the soleus could be defined as a high percentage of H, HF, F and low Ms responses muscle. Flexor hallucis brevis and abductor pollicis brevis had high F, very low H, HF and low or moderate Ms response muscles. In the latter, the percentage of Ms potentials was significantly higher than in the former. A very high percentage of Ms potentials was found to be an outstanding attribute of extensor digitorum brevis, as it never develops H or HF but only F potentials. The occurrence of H, HF, F and Ms responses in different limb muscles corresponded closely to that found in adults. There was no significant correlation with age. The potential type frequency of occurrence in individual muscles with aging remained more or less constant. There was no correlation with nerve conduction velocities (significantly slower during the first months of life) either. The results appear to favor the genetic determination of the electrophysiological phenomena observed, through motor units structure and function.

The systematic analyses of secondary muscle potentials of H-reflex and F-wave type were done in multicentric study. The examinations were carried out in healthy volunteers with 9 muscles analysed on the legs and 9 on the lower arms and hands. The H-reflex potential was found regularly in thigh muscles (vastus medialis 100%, biceps femoris 97%, semitendinosus 93%). Less frequently but still with high incidence it appeared in posterior lower leg muscles (soleus 93%, caput mediale gastrocnemii 73%). In anterior tibial muscle and extensor digitorum brevis it did not appear at all. Only exceptionally it was found in short peroneal muscle (3%) and occasionally, only on proximal nerve stimulation, in flexor hallucis brevis. The similar distribution pattern was found in lower arm and hand muscles with analysis on both sides. In flexor digitorum superficialis (73-70%) and flexor carpi radialis (73-57%) the percentage of H-potential muscles was the highest, in flexor carpi ulnaris (47-40%) lesser but still remarkable. Brachioradialis (37-30%) and extensor digitorum communis (27-27%) percentage decreased further. The even more distal, pronator quadratus (21-20%) and abuctor digiti minimi (17-17%) presented as muscles with low incidence of H-reflex positivity. In extensor indicis proprius (3%) the lowest H-potential incidence was found and in opponens pollicis no H-potential at all. F-waves if evaluated as "F-frequency" follow the similar distribution pattern. The lowest "F-frequency" was found on the legs in anterior tibial, short peroneal and extensor digitorum brevis muscles. In the last one more than one half of stimuli failed to evoke the F-potential. Those are the muscles in which H-potentials almost never appeared. The highest "F-frequency" was recorded in thigh, posterior lower leg muscle and flexor hallucis brevis. Some of the examinees displayed in almost all examined muscles H-potential (6 of 30), the others (9 of 30) had it in neither one or in a single muscle. It looks like as if a kind of H-reflex or F-wave individuals exist. If the H- or F-potentials distribution pattern got projected on the homunculus in quadrupedal position the following idea appears. The thigh muscles, the plantar flexors of the feet and hand and finger flexors are first of all tonic muscles mostly involved in standing or holding. The extensors of the foot/toes, respectively of hand/fingers interrupt phasically the sustained action of standing by lifting the foot/hand from the ground. The muscles with mostly tonic function produce much H-reflexes, transitional forms or at least F-wave with high "F-frequency". Is that a kind of phylogenetical remnants, better developed in the motorically less differentiated legs? Have the H-reflex muscles if compared with F-wave muscles different motor units structure? Have they different motoneurons, with different liability to produce recurrent discharges?

The systematic overview of spontaneous motor unit or muscle fiber activity is presented. In Part 1 the precise clinical description of fasciculations, myokymia and cramps/spasms was made using a dynamic holistic approach. The differences are often a matter of excitation quantity. Correlations with electrophysiological findings were elaborated on the grounds of literature data and personal experience. Electrophysiological correlations with clinically visible fasciculations resulted in the finding that the same clinical phenomenon may have many entirely different electrophysiological correlates. The special forms of repetitive discharges were described additionally: positive giant potentials of quadriceps muscles appearing in healthy muscular individuals and grouped potential discharges of very chronic nerve ending involvement. The electrophysiological features and genesis of many motor unit hyperexcitability signs were discussed, while topic differentiation possibilities and symptomatic treatment were recommended for some. The spontaneous activity in different nosological entities was presented in Part 2. Again the literature data on diseases with conspicuous fasciculations, myokymia and cramps with additional personal experiences (pesticide intoxication, Isaacs syndrome, hereditary autosomal cramp disease, chronic syndrome due to parathyroid insufficiency, chronic tetanus and others) were presented. A description was also given of personal observations in strictly localized forms: single nerve or root lesions and in M. Romberg patient. Symptomatic and causal treatment was suggested for some of them. Clinically similar signs may have entirely different causes responding specifically to carbamazepine, D3, PAM, or surgical decompression. The electromyographic finding may remain clinically silent even in myotonia.

Autosomal dominant motor and sensory neuropathy with liability to pressure palsies was studied in three members of the same family. Only one of two monozygotic twin sisters was clinically affected. She developed unilateral peroneal palsy twenty minutes following local pressure. Electromyography revealed a weak intermediate innervation pattern with very rapid action potentials in the right anterior lower leg muscle. A 25-70 per cent reduction of motor and sensory conduction velocity was recorded in the clinically unaffected twin sister and in the father. The electrophysiological findings in the mother were normal. The sural nerve biopsy revealed "sausage-like" formations. The palsy persisted for two months and disappeared after eight weeks of fluocortolon treatment. It is possible that the myelin sheaths acted as antigen.

In 62 healthy volunteers, a late response analysis was done in 23 leg and arm muscles. The potentials were differentiated according to their H-potential or F-potential features. The total disappearance of secondary potential was estimated also. The H-potential appeared most frequently in the thigh muscles (100%), frequently in the calf and peroneus longus muscles (77%-23%), rarely in the intrinsic foot muscles (20%), and never in the short or long foot and toe extensors. In the arms the H potential was most frequently found in flexor digitorum sublimis (67%). Its appearance in pronator quadratus was 22%. H-potential appeared rarely in the intrinsic hand muscles and never in the extensor digitorum communis. The similarity of H-wave distribution in the lower leg and feet muscles, and the lower arm and hand muscles is pointed out. The question of its phylogenetic determination is raised.

Electromyographic neuromuscular testing was performed for two patients with a very low blood cholinesterase activity due to suicidal poisoning with organophosphorous pesticides. Electromyographic results did not differ significantly from those obtained in healthy nonexposed adults. Neuromuscular synapse functioning was normal, as was determined by electromyography. Neurological signs and symptoms are described in detail. Language: en