Erik Stålberg, born 1936, entered Clinical Neurophysiology in 1967 after his thesis on propagation velocity in human muscle fibres. He was chairman and head of the Dept of Clin Neurophysiology, Uppsala University Hospital from 1991 and also Professor in Clinical Neurophysiology from 1993 until retirement. He has developed EMG methods such as SFEMG, Macro EMG, Scanning EMG and has developed quantitative parameters to describe human motor units in health and disease.

In this lecture I will present two out of many methods to test the neuromuscular function, Repetitive Nerve Stimulation (RNS) and Single fiber EMG (SFEMG).
The physiological background to RNS will be discussed as well as and methodological principles, stimulation protocol and pitfalls. When performed in proximal temperature-controlled muscles, the sensitivity is up to 80% in generalized myasthenia and about 50% in ocular myasthenia.
Jitter analysis is nowadays usually performed with small concentric needle electrodes. It is quite possible to obtain acceptable signals. Special criteria to accepted signals are not further discussed, but references are given.
The method is applied both for volitional activation and for electrical stimulation. Recordings from normal muscle and from myasthenia are shown. New reference values compared to those previous used for SFEMG are given. The sensitivity in detecting neuromuscular dysfunction is same for concentric recording as for proper SFEMG recordings. Overall the sensitivity is higher than 95%.