Axial myopathy: an overlooked feature of muscle diseases

Abstract

Classically, myopathies are categorized according to limb or cranial nerve muscle affection, but with the growing use of magnetic resonance imaging it has become evident that many well-known myopathies have significant involvement of the axial musculature. New disease entities with selective axial muscle involvement have also been described recently, but overall the axial myopathy is unexplored. We performed a PubMed search using the search terms 'myopathy', 'paraspinal', 'axial' and 'erector'. Axial myopathy was defined as involvement of paraspinal musculature. We found evidence of axial musculature involvement in the majority of myopathies in which paraspinal musculature was examined. Even in diseases named after a certain pattern of non-axial muscle affection, such as facioscapulohumeral and limb girdle muscular dystrophies, affection of the axial musculature was often severe and early, compared to other muscle groups. Very sparse literature evaluating the validity of clinical assessment methods, electromyography, muscle biopsy and magnetic resonance imaging was identified and reference material is generally missing. This article provides an overview of the present knowledge on axial myopathy with the aim to increase awareness and spur interest among clinicians and researchers in the field.

Transforaminal lumbar puncture for intrathecal nusinersen administration

“…Isolated paraspinal weakness is rare, although it can be found in other myopathies such as sporadic late onset nemaline myopathy, Pompe disease, McArdle disease, facioscapulohumeral muscular dystrophy, or myopathies produced by mutations in the dysferlin, selenoprotein, or RYR-1 genes. 8 In recent years, whole-body muscle MRI studies have demonstrated subclinical involvement of paraspinal muscles in several muscular dystrophies. 9 Muscle biopsy findings in our MLS patient did not seem disease-specific.…”

McLeod syndrome is a new cause of axial muscle weakness

“…In general, paraspinal muscle weakness is associated with a more widespread myopathy. Isolated paraspinal weakness is rare, although it can be found in other myopathies such as sporadic late onset nemaline myopathy, Pompe disease, McArdle disease, facioscapulohumeral muscular dystrophy, or myopathies produced by mutations in the dysferlin, selenoprotein, or RYR‐1 genes . In recent years, whole‐body muscle MRI studies have demonstrated subclinical involvement of paraspinal muscles in several muscular dystrophies…”

Muscle MRI in neutral lipid storage disease (NLSD)

“…Taken together, this combination of muscle involvement in lower and upper limbs composes a constant pattern and represents a signature of NLSD-M in all stages of the disease. In the clinical context, muscle MRI may help to recognize NLSD-M among different conditions affecting predominantly proximal upper limbs with neck extensor weakness (''man in the barrel'' or ''dropped head'' syndromes) [31][32][33][34] or among different metabolic myopathies, notably those associated with lipidosis on the muscle biopsy [35]. Nevertheless, more muscle imaging data are needed from these other conditions to establish if the ''MRI signature'' in NLSD-M is specific when compared to other muscle lipidosis.…”