Advanced electrodiagnostic studies

Abstract This chapter builds on the basic nerve conduction and electromyography (EMG) recording techniques covered in the previous chapter (Chapter 5). Interpretation of needle EMG findings is covered, including neurogenic vs myopathic findings, remodelling of motor unit potentials (MUPs) over time, quantitative EMG (including interference pattern analysis, motor unit number estimate) and single-fibre EMG. Advanced nerve conduction study recordings covered in this chapter include: - cranial nerve recordings - pelvic floor recordings (including bulbocavernosus reflex, pudendal-urethral reflex, pudendal-anal reflex, pudendal nerve somatosensory evoked potentials, dorsal penile sensory conduction in males, pudendal nerve terminal motor latency, perineal sympathetic skin responses, common cases and reference values as well as nerve stimulation treatment applications) - late responses (including F-waves and H-reflexes) - axonal excitability testing (including threshold tracking) - reflex studies (including jaw jerk, startle reflex, blink reflex recovery, prepulse inhibition, stretch reflex, flexor withdrawal reflex) - repetitive nerve stimulation for various muscles - exercise testing (short-exercise testing with cooling and long-exercise testing). Technological challenges, solutions and report-writing are outlined. Reference values for MUP duration, recruitment and jitter are provided.