Beyond the Clinical Trial: The Role of the Physical Therapist in Diagnosis and Management of a Patient with Spinal Muscular Atrophy Type II

Background: Spinal Muscular Atrophy (SMA) is an autosomal recessive neuromuscular condition characterized by progressive loss of muscle function. Mutation of the survival motor neuron (SMN1) protein results in degradation of motor neuronal pools. Despite variability in phenotypic expression, SMA is classified into subtypes based upon achievement of gross motor milestones. Purpose: The purpose of this case report is to highlight the physical therapist’s role in reducing diagnostic delays and in the ongoing management of SMA while discussing the impact of medical advancements. Case Description: The patient was diagnosed with SMA Type II at 17 months of age following evaluation for delayed milestones. The child presented with significant hypotonia and decreased muscle strength with a Gross Motor Quotient of 61 on the Peabody Developmental Motor Scale (PDMS-2). The patient is currently 8 years old and utilizes a power mobility device. Breath support strategies have been implemented to improve control of respiratory muscles in addition to resistance exercise and postural control training. Outcomes: Forced Vital Capacity (FVC) is frequently used to monitor respiratory status, but Maximum Phonation Time (MPT) and rib cage excursion may provide alternative means of assessment. Additional measures included the Hammersmith Functional Motor Scale Expanded (HFMSE), Sitting Balance Scale (SBS), and Canadian Occupational Performance Measure (COPM). Discussion: Diagnosis of neuromuscular diseases is complicated by variability in clinical presentation and lack of expertise by healthcare professionals. Increased awareness and knowledge of red flag warning signs will help decrease delays in diagnosis and improve access to medical services. Further, the progressive nature of SMA can make it difficult to show improvement using functional outcome measures. Participation-based measures provide a means to demonstrate meaningful change throughout habilitation