Phrenic Nerve and Diaphragm Electrophysiology in Pompe Disease

ConditionPompe Disease
Trial statusRecruiting
Trial phaseNot listed
Trial typeObservational
Biological sexAll
Age18+
SponsorIRCCS National Neurological Institute "C. Mondino" Foundation

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 volunteers

Qualifiers

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

Design model

Case-only

Time perspective

Prospective

Treatments tested in this trial

Not listed

Trial groups

No trial groups listed

Trial outcomes

Primary outcomes

1

Motor latency (ms)

Phrenic nerve conduction parameter measured by bilateral nerve conduction studies

Time frame
Baseline (at first available assessment, retrospective or prospective)
2

Compound muscle action potential (CMAP) amplitude (millivolts)

Phrenic nerve conduction parameter assessed bilaterally by nerve conduction studies

Time frame
Baseline (at first available assessment, retrospective or prospective)
3

Presence or absence of diaphragmatic responses

Phrenic nerve conduction parameter assessed bilaterally

Time frame
Baseline (at first available assessment, retrospective or prospective)

Secondary outcomes

1

Neurogenic pattern

Diaphragm electromyography pattern assessed when clinically indicated

Time frame
Baseline (at time of clinical assessment when EMG is performed)
2

Myopathic pattern

Diaphragm electromyography pattern assessed when clinically indicated

Time frame
Baseline (at time of clinical assessment when EMG is performed)
3

Mixed pattern

Diaphragm electromyography pattern assessed when clinically indicated

Time frame
Baseline (at time of clinical assessment when EMG is performed)
4

Normal pattern

Diaphragm electromyography pattern assessed when clinically indicated

Time frame
Baseline (at time of clinical assessment when EMG is performed)

Other outcomes

Sponsors and contacts

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