Quantification of concentric-needle-induced insertional activity by turn/amplitude analysis

Area of Science:

• Neurology
• Clinical Electrophysiology

Background:

• Needle-induced insertional activity (IA) is a standard EMG component.
• Quantification of IA using turn/amplitude analysis (TAA) has not been previously explored.

Purpose of the Study:

• To evaluate the diagnostic utility of TAA for quantifying IA in neuromuscular disorders.
• To compare TAA parameters with conventional EMG sensitivity.

Main Methods:

• IA was recorded from the brachial biceps and anterior tibial muscles of healthy subjects and patients with neuropathies and myopathies.
• IA was analyzed for duration (IAD), turns/second (T/S), amplitude/turn (A/T), and their ratios with IAD.
• Statistical analysis compared parameters between healthy and diseased groups.

Main Results:

• IA duration (IAD) did not differ significantly between healthy and diseased subjects.
• Turns/second (T/S), amplitude/turn (A/T), and their ratios with IAD were significantly increased in neuropathies.
• In myopathies, T/S and T/S:IAD were increased, indicating broader diagnostic applicability.

Conclusions:

• Quantification of IA by TAA enhances EMG sensitivity for detecting neuromuscular disorders.
• TAA significantly increases diagnostic sensitivity, particularly for neuropathies and myopathies.
• Turns/second (T/S) is identified as the most sensitive parameter for diagnosing both neuropathies and myopathies.