Hydroxymethylglutaryl-coenzyme A (HMG CoA) reductase antibody-associated myopathy is a rare but serious condition that can present with progressive muscle weakness. While limb weakness is a common feature, bulbar involvement is rarely reported. We present a unique case of a 74-year-old female presenting with severe dysphagia, followed by subsequent proximal lower extremity weakness after initiation of statin therapy.

74-year-old female past medical history of hyperlipidemia and invasive ductal carcinoma presented with four weeks of progressive dysphagia. She subsequently developed bilateral proximal lower extremity weakness, and gait instability. She reported starting statin therapy for newly diagnosed hyperlipidemia one-month prior to symptom onset. Laboratory tests revealed elevated creatinine phosphokinase levels, indicating severe rhabdomyolysis. Examination revealed weakness in hip and knee movements, swallowing dysfunction, and subtle, chronic left eye ptosis. Her dysphagia continued to worsen, requiring short-term intubation for airway protection. MRI of the thighs revealed diffuse enhancement, and a muscle biopsy of the left thigh showed type II myofiber atrophy. Myasthenia gravis (MG) labs, autoimmune, and paraneoplastic panels were unremarkable. However, she had markedly elevated HMG-CoA reductase antibody levels, (>550 units). Given the rarity of bulbar symptoms in this condition, she received Intravenous Immunoglobulin (IVIG) to rule out coexisting seronegative MG or paraneoplastic syndrome, which was ineffective. She was then treated with high-dose pulse steroids, followed by an oral taper, leading to significant improvement.

This case highlights a rare presentation of HMG-CoA reductase antibody-associated myopathy with prominent bulbar symptoms, including severe dysphagia, which can complicate diagnosis and management. While proximal limb weakness is typical manifestation, clinicians should be aware that statin-associated myopathy can present with significant bulbar involvement. Early recognition and initiation of immunosuppressive therapy such as high-dose steroids, can lead to marked improvement in symptoms, underscoring the importance of considering this diagnosis even when bulbar symptoms predominate.