Electrophysiological studies were undertaken on 29 patients with Alzheimer's Disease. A reduction in the number of functioning motor units was found in the extensor digitorum brevis muscle. The electrophysiological parameters of the motor unit potentials were increased compared to control values. Four of seven muscle biopsies showed abnormalities ranging from mild to severe. The results suggest...

This paper deals with the online decomposition of intramuscular electromyographic (iEMG) signals. A Markov model is proposed, which takes into account a varying number of firing motor neurons. A Bayes filter detects online the firing motor units by using a dictionary of approximated motor unit action potentials waveforms, and estimates precisely the action potential shapes and the respective fi...

The sartorius muscle is the longest muscle in the human body. It is strap-like, up to 600 mm in length, and contains five to seven neurovascular compartments, each with a neuromuscular endplate zone. Some of its fibers terminate intrafascicularly, whereas others may run the full length of the muscle. To assess the location and timing of activation within motor units of this long muscle, we reco...

A 22-year-old woman visited our clinic with a history of radiofrequency volumetric reduction for bilateral masseter muscles at a local medical clinic. Six days after the radiofrequency procedure, she noticed a facial asymmetry during smiling. Physical examination revealed immobility of the mouth drawing upward and laterally on the left. Routine nerve conduction studies and needle electromyograp...

Electrodiagnostic studies play an important role in the evaluation of patients suspected of having a myopathic disorder. They are used to exclude alternative diagnoses, confirm the presence of muscle disease, narrow down the differential, and identify an appropriate biopsy site. The most informative part of the electrodiagnostic study is needle electromyography. This allows for the analysis of ...

Motor units of segmental tail muscles were recorded in awake rats following acute (1-2 days) and chronic (>30 days) sacral spinal cord transection to determine whether plateau potentials contributed to sustained motor-unit discharges after injury. This study was motivated by a companion in vitro study that indicated that after chronic spinal cord injury, the tail motoneurons of the sacrocaudal ...

In clinical electromyography the muscle is examined not only in regard to voluntary activity and "spontaneous" activity, but also as regards the response on mechanical stimulation by the exploring needle electrode. According to Weddell and others (1944), the response of the normal muscle consists of a short outburst of action potentials which can be distinguished from normal motor unit action p...

Auditory event related potentials (ERPs) and visual evoked potentials (VEPs) were recorded from eight patients with Parkinson's disease, before and after a single dose of apomorphine. To assess the treatment effects, the patients' motor state, Benton visual retention test (BVRT), and digit span tests were also examined. After apomorphine, although motor performance improved, the ERP latencies w...

in this paper, computer simulation of a three-phase synchronous motor drive is described. this drive/system is supplied with a new type of pulse-width modulated voltage source inverter (pwm vsi) whose amplitude of the first harmonic, compared to a conventional sinusoidal pwm vsi, is increased by about 17% and whose amplitude of higher harmonics is also reduced inversely proportional to their or...