Clinical Reasoning: Adult Patient Presenting With Spine Pain Following a Motor Vehicle Accident

A 52-year-old female with a complex past medical history, including history of consanguinity, developed refractory, uncontrollable spine pain following a motor vehicle accident two years prior to presentation. There were no well-defined findings on clinical examination. She was found to have mildly elevated serum CPK levels and spine imaging revealed fatty replacement and atrophy affecting predominantly lumbar paraspinal muscles. Initial EMG sampling of multiple limb muscles was normal. However, follow up concentric needle examination sampling paraspinal and trunk muscles showed abundant myotonic discharges, fibrillations and positive sharp waves, and myopathic motor unit action potential changes. This pattern of neurophysiological abnormalities prompted the search for a myopathic disorder, which was ultimately confirmed with additional studies. This case highlights the critical role of neurophysiological evaluation of paraspinal and other trunk muscles in the disambiguation of clinical and imaging data, helping to establish the diagnosis of a rare but treatable myopathy at early disease stages.