When Metabolism Recovers but the Brain Does Not: A Case Report of Posterior Reversible Encephalopathy Syndrome (PRES)-Like Encephalopathy After Extreme Metformin-Associated Lactic Acidosis
Abstract
Metformin-associated lactic acidosis (MALA) is a rare but life-threatening complication of metformin therapy. Neurological manifestations are usually considered reversible and are classically associated with basal ganglia involvement on magnetic resonance imaging (MRI). A 63-year-old man with previously normal renal function developed severe MALA after continuing metformin during a gastrointestinal illness. He presented with profound metabolic acidosis (pH 6.55), extreme lactate elevation to 29.9 mmol/L, acute kidney injury, and hemodynamic collapse requiring resuscitation. Toxic metformin levels confirmed the diagnosis. Despite rapid metabolic stabilization with renal replacement therapy, persistent encephalopathy remained. Serial MRI revealed bilateral cerebellar and posterior cortical vasogenic edema with contrast enhancement, without diffusion restriction, consistent with a posterior reversible encephalopathy syndrome (PRES)-like pattern. Severe cortical visual impairment persisted. This is the first detailed report describing a PRES-like radiological pattern in the setting of confirmed severe MALA without the classical lentiform fork sign. Furthermore, we report a survivor of an initial lactate level of 29.9 mmol/L - one of the highest lactate concentrations ever reported in a surviving patient. This case challenges the assumption that neurological manifestations of MALA are uniformly reversible and expands the radiological spectrum of metformin-associated brain injury.…
How strong is the evidence?
Evidence Hub reads this as a case report, done in people. Its evidence level is 5 of 5 (Very low · case / narrative / animal / in vitro / in silico). Case reports, narrative reviews, and animal, cell or computer-model studies give the weakest evidence for human health.
Read the paper
Related studies
- Metformin as an adjuvant in breast cancer treatment
- Metformin Lysosomal Targeting: A Novel Aspect to Be Investigated for Metformin Repurposing in Neurodegenerative Diseases?
- Aberrant HSF1 signaling activation underlies metformin amelioration of myocardial infarction in mice
- Metformin induces ZFP36 by mTORC1 inhibition in cervical cancer-derived cell lines
- Protein Interaction Network for Identifying Vascular Response of Metformin (Oral Antidiabetic)
- Preventing Long COVID With Metformin
Go deeper in Evidence Hub
Evidence Hub adds a study data sheet (design, sample size, evidence level, key numbers), an AI summary and a chat grounded in the paper's text.