Under the radar: Bilateral phrenic nerve palsy as a cause of progressive dyspnea.

Bilateral phrenic nerve palsy is a rare phenomenon with varying etiology. We present a case of bilateral phrenic nerve palsy postulated to be the first manifestation of Systemic Lupus Erythematosus. Our patient was a 67 year old female with history of neuroendocrine tumor with lung metastases status post right upper lobe lobectomy, ovarian cancer status post hysterectomy, and chronic obstructive pulmonary disease (COPD) who initially presented to another hospital with a 6 month history of progressive dyspnea and acute on chronic hypercapneic respiratory failure with poor response to therapy. Interestingly, she was admitted twice in the 6 weeks prior for suspected COPD exacerbation. Extensive investigation for primary pulmonary process was negative and patient required non-invasive positive pressure ventilation (NIPPV). An initial chest X-ray showed a new left diaphragm elevation, with subsequent chest X-rays revealing bilateral elevated diaphragm. Neurologic exam was otherwise non-focal. She underwent MRI of the cervical spine and right shoulder that showed mild degenerative changes and cervical spondylosis at C4 through C7. CT chest was unremarkable. She was transferred to our hospital for further evaluation. Electromyography confirmed bilateral phrenic nerve palsy with no evidence of myopathy or Lambert-Eaton syndrome. Extensive work up was unyielding except for a positive Anti-nuclear antibody (1:640 homogenous pattern) and anticardiolipin antibody (IgM), with negative dsDNA, ENA and SSA and SSB antibodies. C3 and C4 were within normal range. We suspected SLE manifesting as bilateral diaphragmatic palsy, initiated empiric methylprednisone in hopes that her symptoms would improve. While exploring options for diaphragmatic pacing, comfort care was pursued due to patient\u27s pre-stated wishes and patient passed away peacefully. Literature review reveals cases of bilateral phrenic nerve palsy associated with surgical trauma (such as after a cardiothoracic or cervical procedure), neuromuscular disorders, extrinsic compression or injury to the phrenic nerve, spinal cord disorders, and neuropathic diseases including autoimmune disease. Bilateral phrenic nerve palsy has been reported to be a manifestation of SLE, at times as the first clinical manifestation. Shrunken lung syndrome has also been recognized with Sjogren\u27s syndrome. Therapy is limited to steroids and NIPPV and some isolated response to Rituximab. Prognosis appears to be mixed, paralysis may improve spontaneously after a long course, or may persist and progress. Other options for treatment are diaphragmatic pacing and plication of the diaphragm. Being cognizant of this diagnosis and instituting early therapy may alter clinical response