A 69 year old male who lives in Michigan with a past medical history significant for chronic pulmonary obstructive disease and hypertension presented with worsening dyspnea that began while vacationing in Florida. Prior to the development of dyspnea, he noted a rash with a burning sensation over the right neck and arm encompassing the cervical dermatomes 3, 4 and 5. He was subsequently diagnosed with shingles. A course of prednisone was prescribed due to continued pain after the lesions healed. During the course of prednisone therapy, he noted worsening dyspnea especially while lying supine and exercising. He sought medical attention upon returning home to Michigan, approximately 4 weeks after he was diagnosed with shingles. Physical examination including vital signs was unremarkable. He was saturating 92% on ambient air on the day of examination. A chest X-ray showed severely restricted lung volumes. Due to suspicion for unilateral diaphragmatic paralysis, he received a fluoroscopic sniff test. This confirmed the diagnosis of right diaphragmatic paralysis. He was monitored closely over the next few months without intervention. During his one year follow-up, he continued to have subjective dyspnea.
Unilateral diaphragmatic paralysis may arise from a variety of causes such as trauma, mass lesions and viral infections. Although rare, diaphragmatic paralysis resulting from Herpes zoster infection of the cervical nerve roots 3, 4 and 5 has been described in the literature. Shingles rash that began over the right cervical dermatomes 3, 4 and 5 prior to developing dyspnea and a positive fluoroscopic sniff test is consistent with this diagnosis. Patients with unilateral diaphragmatic paralysis are often asymptomatic because the contralateral diaphragm is able to compensate for the paralyzed diaphragm during inspiration. Although our patient had a diagnosis of unilateral diaphragmatic paralysis, the exact etiology of his dyspnea remains unclear. One potential explanation could be his low functional lung reserve from chronic obstructive pulmonary disease leading to incomplete compensation of left diaphragm. Unilateral diaphragmatic paralysis usually carries an excellent prognosis. Treatment options include treating contributing factors such as sleep-disordered breathing and surgical options such as surgical plication of hemidiaphragm and phrenic pacing.
Unilateral diaphragmatic paralysis is a rare but important differential to consider for patients presenting with worsening dyspnea with a recent history of shingles involving the cervical dermatomes. It usually is well tolerated and most people do not require treatment.