The effect of Jendrassik maneuver on the persistence of the peroneal nerve F-wave.

Objectives: This study investigated whether peroneal nerve F-wave persistence increased when the Jendrassik maneuver (JM) was performed, aiming to obtain information about the physiology of F-waves and JM. Patients and methods: Thirty healthy individuals (HIs; 17 females, 13 males; mean age: 33.6±8.2 years; range, 23-50 years) were included in the prospective experimental study conducted between June 15, 2021, and December 15, 2021. Nerve conduction studies of peroneal, superficial peroneal, posterior tibial, and sural nerves were performed in one extremity of each HI. The peroneal nerve F-wave study was performed at rest (Study 1), during JM (Study 2), and after JM (Study 3). F-wave persistence of the peroneal nerve, maximum F-wave amplitude (ampF-wavemax), mean F-wave amplitude (ampF-wavemean), minimum F-wave latency, and the ratio of ampF-wavemean to maximum M amplitude (F/M ratio) were analyzed. Results: The mean peroneal nerve F-wave persistence in Study 1, Study 2, and Study 3 was 28.7±23.9%, 52.3±32.1%, and 34.7±29.0%, respectively. F-wave persistence in Study 2 was higher compared to Studies 1 and 3 (p<0.001 and p<0.001, respectively). Moreover, ampF-wavemax, ampF-wavemean, and F/M ratio in Study 2 were higher than Studies 1 and 3 (p=0.026 and p=0.021 for ampF-wavemean; p=0.015 and p=0.003 for ampF-wavemax; p=0.033 and p=0.015 for F/M ratio, respectively). F-wave persistence in Study 2 was positively correlated with ampF-wavemax and ampF-wavemean (p<0.001, r= 0.717; p<0.001, r=0.786, respectively). Conclusion: This study demonstrated that JM increased F-wave persistence and amplitude. Jendrassik maneuver may show its effect through motor neuron excitability.

Needle electromyography abnormalities in the upper trapezius muscle in neuromuscular disorders.

BACKGROUND: : Needle electromyography (EMG) abnormalities in the trapezius muscle (TM) can be seen in neuromuscular disorders. The aim was to determine the characteristics of needle EMG abnormalities observed in the TM in neuromuscular disorders. METHODS: The data of patients who applied to the Clinical Neurophysiology Laboratory of University of Health Sciences Adana City Training and Research Hospital between December 2018 and October 2021 were reviewed. Polio survivors, amyotrophic lateral sclerosis (ALS) patients, patients with sensorimotor polyneuropathy, patients with spinal cord lesions involving C2/C3/C4 segments, patients with spinal accessory nerve (SAN) lesions, neuralgic amyotrophy (NA) patients, and patients with myopathy were included. Needle EMG findings of the upper TM of the patients were analyzed. Positive sharp waves, fibrillation potentials, fasciculation potentials, myotonic discharges, and motor unit action potential (MUAP) changes were considered needle EMG abnormalities. RESULTS: Eighty-one polio survivors, 23 ALS patients, 39 patients with sensorimotor polyneuropathy, 10 patients with cervical spinal lesions, eight NA patients, seven patients with SAN lesions, and three patients with myopathy were included in the study. Fifteen (65.2%) ALS patients, 18 (22.2%) polio survivors, three (30%) patients with cervical spinal lesions, two (5.1%) patients with sensorimotor neuropathy, one (12.5%) NA patient, seven (100%) patients with SAN lesions, and two (66.7%) patients with myopathies had at least one needle EMG abnormality in the TM. Fasciculation potentials in the TM were seen in 10 (43.5%) ALS patients. In four patients with SAN lesions and one polio survivor, MUAP could not be obtained from the TM. DISCUSSION: There may be more frequent needle EMG abnormalities, particularly in ALS patients and patients with SAN lesions. Since the number of patients with myopathy included in this study was low, it is difficult to comment on the needle EMG features of the TM for these patients. In addition, this study indicated that fasciculation potentials in the TM are typical in ALS patients and that MUAP may not be obtained from the TM in patients with SAN lesions.

The needle electromyography findings in the neurophysiological classification of ulnar neuropathy at the elbow

Background/aim: Although ulnar neuropathy at the elbow (UNE) is the second most common entrapment mononeuropathy, there are few reports on its neurophysiological classification. In this study, we tried to find out the role of needle electromyography (EMG) in the neurophysiological classification of UNE. Materials and methods: UNE patients who met the clinical and neurophysiological diagnostic criteria and healthy individuals were included in this study. Reference values of nerve conduction studies were obtained from healthy individuals. Needle EMG was performed to all UNE patients. According to the neurophysiological classification proposed by Padua, UNE patients were classified as mild, moderate, and severe. Results: Thirty-one controls and thirty-five UNE patients were included in the study. There was mild UNE in 23 patients, moderate UNE in 8, and severe UNE in 4. Abnormal needle EMG findings were present in all patients with moderate and severe UNE and in 12 patients with mild UNE. Conclusion: Abnormal needle EMG findings are seen in most of the UNE patients. Therefore, it is not practical to use needle EMG findings in the neurophysiological classification. Needle EMG abnormalities may also be present in patients with mild UNE due to axonal degeneration or motor conduction block.