Unilateral Diaphragmatic Paralysis Secondary to Neuralgic Amyotrophy—a Case Report

Unilateral diaphragmatic paralysis is often discovered incidentally on a chest radiograph and is an underreported cause of dyspnea on exertion. The common causes of diaphragmatic paralysis seen in clinical practice are phrenic nerve injury following blunt neck trauma or surgery, viral infections (e.g., herpes zoster, poliomyelitis), cervical spondylosis, and cervical or mediastinal compressive tumors. Herein, we describe a case of a middle-aged male who presented with breathlessness on exertion, preceded by a history of acute right-sided shoulder, and neck pain. On examination, there were reduced movements of the right hemithorax, and his chest radiograph showed an elevated right hemidiaphragm. On detailed evaluation and based on his clinicoradiological profile along with nerve conduction studies, he was diagnosed as a case of unilateral paralysis of the right hemidiaphragm secondary to neuralgic amyotrophy. Diaphragmatic dysfunction in the form of weakness or paralysis can be a rare consequence of neuralgic amyotrophy. The clinical outcome of neuralgic amyotrophy with phrenic nerve palsy leading to diaphragmatic paralysis is variable, and many patients may show slow spontaneous recovery.