Case Presentation: We report a case of a 52-year-old woman with chronic pain, depression, and poorly controlled diabetes who presented with acute hypoxic respiratory failure secondary to multifocal Streptococcus pneumoniae pneumonia and empyema. During a protracted ICU course requiring mechanical venitation and tracheostomy, she exhibited persistent neurological abnormalities including dystonia and tremor, which, along with ataxic gait, were consistent with symptoms the patient’s family confirmed she had been experiencing prior to admission. Detailed social history revealed chronic, high-dose kratom use–approximately 100 grams daily for over one year. Serum manganese levels were markedly elevated at 86.6 ng/mL (reference: 0.5-1.2 ng/mL), and brain MRI demonstrated bilateral T1 hyperintensities in the basal ganglia, consistent with manganese deposition. Laboratory analysis of the patient’s kratom product revealed manganese concentrations of 2.93 mg/g, suggesting a daily intake of nearly 300 mg –over 100times the recommended upper limit. Despite supportive care, the patient’s neurocognitive deficits persisted at discharge.
Discussion: Kratom (Mitragyna speciosa), an unregulated herbal supplement with stimulant and opioid-like properties, has grown in popularity in the United States, particularly among individuals managing chronic pain or opioid withdrawal. Though prior reports have documented its association with opioid-like toxidromes, concerns regarding contamination with heavy metals remain underrecognized. Symptoms, MRI, and serum manganese (Mn) >70× normal are consistent with Mn neurotoxicity from chronic kratom use (≈293 mg/day vs. FDA 2.3 mg/day). Toxicity did not directly cause respiratory failure but likely delayed recovery and worsened neurologic status. Chelation/neuroprotection deferred due to instability and limited follow-up. Diagnosis clarified patient’s course and prognosis, highlighting likely irreversible neurologic deficits.
Conclusions: This case represents, to our knowledge, the first reported instance of manganese neurotoxicity secondary to kratom use. The severity of this patient’s neurological impairment, coupled with biochemical and radiological confirmation and source identification, underscores the risk of heavy metal contamination in unregulated supplements. Clinicians should be aware of the potential for heavy metal toxicity, particularly in patients consuming large quantities.