Something in the Water: An Unlikely Cause of Acute Encephalopathy and Rhabdomyolysis

Author: Lily Nguyen
Program: Resident/Clinical Fellow
Mentor(s): Waleed Kassabo, MD
Poster #: 11
Session/Time: A/2:40 p.m.

Abstract

Introduction:

Rhabdomyolysis, a condition characterized by muscle necrosis and the release of intracellular protein and electrolytes, can lead to acute renal failure. This syndrome can be caused by various factors such as trauma, prolonged immobilization, strenuous exercise, hyperthermia, drugs, toxins, and infections. The following case study presents a unique patient with encephalopathy, dysarthria, and rhabdomyolysis.

Case Information:

A 50-year-old male with no significant medical history was admitted with altered mental status and difficulty speaking. He was found unconscious at home, experiencing malaise, dizziness, and speech impairment. Upon evaluation, he was febrile to 103°F, disoriented to place, noticeably dysarthric, and demonstrated 4/5 lower extremity weakness. Initially, stroke was suspected, but a non-contrast head CT showed no abnormalities. He was subsequently admitted to internal medicine for management.

Clinical Findings:

His initial laboratory results were concerning; transaminitis (aspartate transaminase 208, alanine transaminase 845), troponinemia (reaching 88), acute renal failure (creatinine 2.1), and significantly increased creatine phosphokinase (CPK 116,476). Consultations were requested from nephrology, neurology, cardiology, and infectious disease specialists. Despite intravenous fluids over the next two days, CPK continued to rise, peaking at 163,200, and renal function worsened. Empiric intravenous antibiotics were started for blood cultures that grew Gram-positive bacteria, later identified as Staphylococcus lugdenensis.

Additional information was obtained from the patient's family; they had recently returned from a cruise to the Bahamas, two weeks prior to admission. Since returning home, the patient had become progressively withdrawn. A comprehensive workup was conducted, including urine drug screen, chest X-ray, infectious disease tests, lumbar puncture, and MRI head studies. Toxicology screening was negative. Chest X-ray showed right lower lobe pneumonia and MRI of the head without contrast was concerning for multiple sclerosis lesions. Among the various infectious disease tests, two yielded positive Results: Epstein-Barr virus IgG and Legionella urine antigen. Azithromycin was initiated before hemodialysis, with a corresponding decrease in CPK level. Lumbar puncture results showed increased protein and neutrophils, while other test results were within normal limits. A multiple sclerosis profile and MRI head with contrast confirmed an incidental diagnosis of multiple sclerosis; reviewing the current literature suggested no association with Legionella and the patient's presentation was an acute encephalopathic process. Meanwhile, the patient showed significant improvement with azithromycin, cefazolin (to treat bacteremia), high-dose intravenous steroids for multiple sclerosis flare, and hemodialysis. His dysarthria and encephalopathy resolved, and he was discharged with arrangements for outpatient hemodialysis.

Conclusion:

This case represents an exceptionally rare presentation of Legionnaire's disease. Legionella pneumophilia, the bacteria responsible for this condition, is transmitted through contaminated water, such as in air conditioning or cruise ships. Typical presentations of Legionella infection include pneumonia, hyponatremia, and occasionally, acute encephalopathy. Rhabdomyolysis has been linked to Legionella in 35 reported cases since 1980, with observed improvement after antibiotic treatment targeting the underlying source of muscle breakdown. The recommended course is azithromycin 500 mg daily for 10-14 days. This case contributes to the existing literature, emphasizing the importance of early diagnosis and highlighting that Legionella infection can present with encephalopathy and rhabdomyolysis.