Respiratory management of patients with neuromuscular disease: current perspectives

Figures & data

Table 1 Approach to diagnostic investigations

Clinical presentation	Differential diagnosis	Initial testing
Bulbar weakness	Amyotrophic lateral sclerosis Myasthenia gravis	Electromyography Single-fiber EMG Electromyography Single-fiber EMG AchR-antibody serology
Ophthalmoplegia/ptosis	Myasthenia gravis Mitochondrial myopathy Oculopharyngodistal myopathy	Single-fiber EMG AchR-antibody serology Muscle biopsy Genetic testing Muscle biopsy
Proximal myopathy	Pompe disease Inflammatory myopathy • polymyositis • dermatomyositis • sarcoidosis Limb-girdle muscular dystrophy (2C, D, I)	GAA dried blood-spot assay Muscle biopsy GAA sequencing CK ESR/CRP Chest X-ray Muscle biopsy Antisynthetase antibodies CK Muscle biopsy Genetic testing
Distal myopathy	Inclusion-body myopathy Myotonic dystrophy Myofibrillar myopathy • hereditary myopathy with early respiratory failure (titinopathy) • desminopathy • myotilinopathy • αβ-crystallinopathy • BAG3-opathy	Muscle biopsy Anti-NT5C1A antibody DMPK-expansion genetic testing Muscle biopsy Muscle MRI of legs Genetic testing

Abbreviation: EMG, electromyography; ESR, erythrocyte sedimentation rate; MRI, magnetic resonance imaging; CK, creatine kinase; CRP, C-reactive protein; 2C, D, I: designations for subtypes of LGMD caused by SGCG, SGCA, and FKRP mutations, respectively.

Table 2 Assessment for respiratory muscle weakness

Assessment	Clinical history	Physical exam	Pulmonary function testing	Sleep testing	Thoracic imaging
Bulbar weakness	Aspiration, drooling, voice change, post prandial cough	Change in appearance, drooling	Difficulty with testing due to poor mouth seal. False low values.		Aspiration
Diaphragm/inspiratory muscles	Orthopnea, dyspnea on bending or immersion, sleepiness, morning headaches, decreased stamina speaking	Sleepy, increased respiratory rate, shallow breathing, orthopnea, accessory muscle use	Decreased forced vital capacity, decreased inspiratory pressure, decreased sniff nasal pressure, postural drop in forced vital capacity	REM or sleep hypoventilation
Expiratory muscles	Recurrent infections, weak cough	Decrease in cough volume
Not specific	Dyspnea	General respiratory exam	Decreased peak flow, decreased peak cough flow		Low lung volumes, pneumonia, pulmonary embolism

Abbreviation: REM, rapid eye movement.