Atypical posterior reversible encephalopathy syndrome with hemispheric brainstem and spinal cord involvement in a patient with acute kidney injury – a case report.

Objectives: Posterior reversible encephalopathy syndrome (PRES) is a disorder characterized by variable clinical presentation and MRI features consisting of vasogenic oedema in parieto-occipital regions [1]. The de- scription of cases of atypical PRES has led to reconsidering such syn- drome as a complex and multifaced clinical entity [2]. Herein, we provide clinical and radiological description of a patient affected by atypical PRES. Materials: We describe a case of a 42-year-old man, smoker, with negative clinical history, except for sporadic headaches treated with NSAIDs. Due to an acute episode of headache, vertigo, and subsequent loss of consciousness, he presented to the emergency department where high blood pressure values where reported (240/110 mmhg). He was then admitted to our neurology ward. Methods: The patient was alert and keenly responsive, with mild deficit of left abducens and facial nerves and a remarkable tendency to retropulsion during upright stance. Laboratory tests showed renal failure (Creatinine 3.8 mg/dL, Azotemia 101 mg/dL, Na 131 meq/l, K 2.8 meq/l) and low platelet count (110.000 mm3). Brain MRI showed remarkable hyperintensity in the T2/FLAIR sequences, likely corresponding to vasogenic edema, bilaterally involving centrum semiovale, periventricular white matter, internal and external capsules, thalami, optic chiasm, both vermis and cerebellar hemispheres, the whole brainstem and the spinal cord until C6 level. Hypointensities located in the basal ganglia and cerebellum were observed on susceptibility-weighted imaging, likely corresponding to microhemorrhages. Results: The patient was treated with intravenous nitroglycerin infu- sion until blood pressure normalization. He underwent haemodyalitic treatment due to worsening of his kidney failure. Serologic level of ADAMTS-13 was tested negative. Abdomen ultrasonography showed symmetric, volumetric reduction of both kidneys. The brain MRI, exe- cuted at the normalization of kidney laboratory tests and pressure levels showed remarkable reduction of the T2-FLAIR hyperintensities with total resolution in the spinal cord together with millimetric areas of diffusion Neurological Sciences (2022) 43 (Suppl 1):S1–S530 S13 restriction likely corresponding to cytotoxic oedema. After the placement of an artero-venous fistula the patient was discharged home in good clinical conditions. Discussion: the patient was diagnosed with atypical PRES due to hy- pertension in the setting of acute kidney injury and improved both clinically and neuroradiologically after the removal of the offending cause. Conclusions: While PRES is promptly recognized due to its typical imaging features, atypical and complicated PRES are uncommon and may constitute a diagnostic dilemma, especially when clinical history and examination are poorly suggestive [3]. Patients with atypical PRES, characterized by focal hemorrhages and diffusion restriction may have a poorer prognosis and should be readily recognized. References: 1. Hinchey J. et al. A reversible posterior leukoencephalopathy syn- drome. N. Engl. J. Med. (1996);334:494-500 2. Anderson R. C. et al. Posterior Reversible Encephalopathy Syndrome (PRES): Pathophysiology and Neuro-Imaging. Front. Neurol. (2020);11:1-10 3. Saad A. F., Chaudhari R., Wintermark M. Imaging of Atypical and Complicated Posterior Reversible Encephalopathy Syndrome. Front. Neurol. (2019);10:1-6