Phrenic nerve palsy in patients with neuralgic amyotrophy: case series study

Neuralgic amyotrophy (NA) is a relatively uncommon syndrome causing brachial nerves dysfunction. However, it can also affect other nerves including phrenic nerve, which is often misdiagnosed.

To determine the incidence and characteristics of phrenic nerve palsy in patients with NA in our population, we analyzed the records of all patients with phrenic nerve palsy and/or NA at the University Hospital and the county hospital within the last 10 years. We found that totally, seven patients were confirmed to have NA and phrenic nerve palsy. All of them are male of average age 51.9 years old (51.9±7.4) and had shortness of breath following shoulder and/or neck pain. All of them had elevated diaphragm found in SNIFF test and/or on chest X-ray. Pulmonary function test done in 6 patients demonstrated restrictive lung disease. Six patients needed long-term bi-level positive airway pressure (BiPAP) treatment but mechanic ventilation was not needed.

Our cohort represents one of the largest case series yet reported for phrenic nerve involvement in NA. Most of these patients have had significant pulmonary compromise in the early stage of onset of shoulder/neck pain requiring ongoing BiPAP and specialist monitoring. Recognition of this subset of patients may further require nerve conduction studies/electromyography and respiratory testing.