A 55-year-old female was found unconscious in a ventilated room. She recovered consciousness on the way to the emergency room. Her vital signs were stable. She presented with negativism and poor communication. Physical examination, routine tests, brain CT and electroencephalogram were normal. Urine toxicology was positive for benzodiazepines. Twelve days after, she presented with catatonia and immobility. Additional examinations, including cerebrospinal fluid (CSF) testing and brain CT, were again normal. Risperidone was administered, and psychotherapy intensified. In the third week, the condition worsened, with intense pyramidal signs and decerebration that led to a vegetative state. Brain MRI revealed diffuse leukoencephalopathy. Extensive metabolic and CSF studies were persistently negative. Brain biopsy was compatible with chronic cerebral hypoxia/anoxia. A diagnosis of delayed hypoxic-ischemic leukoencephalopathy was made. Supportive measures were intensified. She was discharged from the hospital after 4 months in a minimally conscious state and was capable of elementary communication and recognising faces.