An uncommon cause of acutely altered mental status in a renal transplant recipient
We report a case of a 57-year-old female with sudden onset of altered mental status (time and person perception) following an episode of seizures, without any kind of hallucinations, and accompanied by headache. She was a kidney transplant recipient, and the above episode occurred on the thirtieth postoperative day after transplantation. She had been diagnosed with end-stage renal disease (ESRD) and had been on hemodialysis for 5 years before she received a graft from a deceased donor in our center. She was also hypertensive and treated with beta-blockers, namely bisoprolol.\nPhysical examination revealed no focal neurological signs such as paralysis, cortical blindness, or Babinski's sign. After the described episode, the patient was generally stuporous with rare incidence of hyperactivity. Her body temperature was normal, blood pressure reached 203/147 mmHg, and the heart rate was 123 bpm. Her Hct at admission was 31.4%, C-reactive protein 1 mg/dL, Hb 9.3 g/dL, and WBC 4794 leukocytes/mm3. TSH, T4, T3, FT3, and FT4 were within normal ranges, and C-reactive protein at episode was 7 mg/dL.\nHer blood pressure was controlled by intravenous esmolol infusion, with no improvement of the clinical status. Her immunosuppression regimen included tacrolimus, corticosteroids, and mycophenolate mofetil, according to our immunosuppression protocol. Serum tacrolimus concentrations were measured continuously and were between 6.5 and 7.5 ng/dL. Although these tacrolimus concentrations are generally considered satisfactory and not capable of triggering a tacrolimus-related encephalopathy, the dose of the drug was further tapered after the episode just to keep serum creatinine within preferred ranges (1.3 mg/dL; eGFR >60 mL/min/1.73 m2).\nAt the same time, a set of examinations was applied, due to the wide spectrum of differential diagnoses mentioned above. Fundoscopic examination and cerebrospinal fluid analysis including cultures and PCR analysis for HSV 1 and 2 showed no abnormalities. Brain computerized tomography (CT) scans showed no hemorrhagic or ischemic lesions. Electroencephalography analysis was not suggestive of epilepsy. MRI of the central nervous system showed signal abnormalities in the pons and the parietal and occipital lobes. More specifically, fluid-attenuated inversion recovery (FLAIR) MRI () revealed high-signal areas in the occipital and parietal lobes (mainly cortical area and subcortical white matter of the right occipital lobe). Furthermore, T2-weighted (T2W) MRI () showed hyperintense signal involving the cortical and subcortical areas of the occipital lobes and the pons. These signal abnormalities were characteristic of vasogenic edema in the above-mentioned brain areas. These lesions were considered as indicative of PRES.\nPsychiatric evaluation, on the other hand, excluded delirium. Antidepressive therapy was administered due to previous history of depression. She was treated intravenously, and 2 days after the initiation of therapy her condition improved significantly. However, her discharge was delayed as the clinical picture was also complicated by an episode of bacteremia, due to multidrug-resistant Pseudomonas aeruginosa, sensitive only to colistin. She was treated with this medication, given in a dose of 9 × 106 IU daily, intravenously for 25 days.\nAt a 6-month follow-up, the patient is in good shape, without presenting similar episodes of altered mental status.