Case Presentation:
A 69‐year‐old female was admitted with generalized weakness, hoarseness, and shortness of breath. She was initially treated as an acute asthma exacerbation. Her past medical history included asthma, type II diabetes mellitus, hypertension, and coronary artery disease status post‐percutaneous intervention. She had been experiencing changes in her voice intermittently for about 4 months. Initial laboratory testing showed normal complete blood counts and normal values on basic metabolic panel. Despite nebulizer treatments, steroids, and antibiotic therapy, the patient continued to experience hoarseness. Under direct visualization via nasopharyngeal laryngoscopy, there were no signs of vocal cord dysfunction or paralysis. A comprehensive metabolic panel was done, and this showed a low magnesium level of 1.4 mEq/L, and the patient was given both intravenous and oral replacement. This corrected her hoarseness of voice, and she was discharged on oral magnesium supplement. Despite being compliant with her magnesium supplementation, her hoarseness continued, and serum magnesium was low on repeat admission. After careful withholding of all magnesium supplements and continuous cardiac monitoring, she underwent a 24‐hour urine collection, which resulted in a urine magnesium level of 574 mg/24 h (RR 12–292 mg/24 h). The patient was diagnosed with symptomatic renal magnesium wasting syndrome and was started on amiloride along with magnesium supplementation. Her hoarseness of voice resolved with normalization of her magnesium levels. At a later date, when the patient was given bowel preparation for a screening colonoscopy, the magnesium levels decreased, and the hoarseness returned. This again resolved with normalization of her magnesium levels.
Discussion:
Magnesium plays an essential role in neuronal and muscle excitability. Neurologic manifestations of hypomagnesemia can include generalized tonic‐clonic seizures and myoclonic activity. Sudden onset of aphasia and intermittent speech arrest has also been reported. This case illustrates an uncommon but likely manifestation of hypomagnesemia as it recurred when the patient's magnesium levels lowered and normalized with improvement in those levels.
Conclusions:
Hoarseness is a frequently encountered symptom that may result from causes ranging from functional disorders to organic lesions affecting the vibratory function of vocal folds or their innervations. Vocal cord paralysis should always be ruled out. Physicians should be aware that hypomagnesemia can also present as dysphonia in susceptible patients, and this can be easily corrected with appropriate supplementation.
Author Disclosure:
M. Krishnamurthy, none; N. Tabassum, none; A. Colpan, none; R. Snyder, none.