About this trial
Pompe disease is traditionally considered a lysosomal myopathy. However, increasing experimental and clinical evidence suggests involvement of the entire motor unit, including motor neurons, peripheral nerves, neuromuscular junctions, and skeletal muscle. Respiratory impairment is a major cause of morbidity and mortality, and diaphragm dysfunction is frequently observed.
Clinical observations at IRCCS Fondazione Mondino have highlighted neurophysiological abnormalities of the phrenic nerve and diaphragm in patients with Pompe disease and respiratory involvement, sometimes occurring even in the absence of clinically significant limb muscle weakness. These findings suggest that respiratory motor unit dysfunction may represent an important component of the disease phenotype.
This observational study aims to systematically characterize phrenic nerve conduction parameters and diaphragm electromyographic findings in adult patients with genetically confirmed Pompe disease and in patients with unexplained respiratory failure. Retrospective and prospective clinical, neurophysiological, and respiratory data collected during routine clinical care will be analyzed to explore whether phrenic nerve and diaphragm abnormalities may serve as markers of respiratory motor unit involvement in Pompe disease.
Eligibility criteria
This trial does not accept healthy volunteersQualifiers
Genetically confirmed diagnosis of Pompe disease.
Ability to undergo routine neurophysiological and respiratory assessments.
Written informed consent provided.
History of restrictive respiratory failure or unexplained hypoventilation.
Disqualifiers
Conditions preventing completion of neurophysiological assessments (e.g., inability to maintain required positioning or relevant clinical contraindications).
Known primary phrenic nerve injury (e.g., postsurgical phrenic palsy or documented traumatic phrenic neuropathy).
Presence of other neuromuscular disorders potentially confounding data interpretation.
Refusal or inability to provide informed consent.
Trial population
Approximately 20 adult patients with genetically confirmed Pompe disease are expected to be prospectively included. In addition, a retrospective review of approximately 150 previously performed phrenic nerve conduction studies and diaphragm electromyography examinations in patients with unexplained respiratory failure will be conducted. The prospective enrollment refers exclusively to newly evaluated Pompe disease patients, while the retrospective component is based on existing clinical records and neurophysiological data
Trial design
Case-only
Prospective
Treatments tested in this trial
Not listed
Trial groups
Trial outcomes
Primary outcomes
Motor latency (ms)
Phrenic nerve conduction parameter measured by bilateral nerve conduction studies
Compound muscle action potential (CMAP) amplitude (millivolts)
Phrenic nerve conduction parameter assessed bilaterally by nerve conduction studies
Presence or absence of diaphragmatic responses
Phrenic nerve conduction parameter assessed bilaterally
Secondary outcomes
Neurogenic pattern
Diaphragm electromyography pattern assessed when clinically indicated
Myopathic pattern
Diaphragm electromyography pattern assessed when clinically indicated
Mixed pattern
Diaphragm electromyography pattern assessed when clinically indicated
Normal pattern
Diaphragm electromyography pattern assessed when clinically indicated
Sponsors and contacts
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IRCCS National Neurological Institute "C. Mondino" Foundation
Lead sponsor
Fondazione Salvatore Maugeri
Collaborator