Uremic Encephalopathy Presented as Stroke: The Value of Lentiform Fork Sign

Abstract

Uremic encephalopathy (UE) is a neurological complication of renal failure characterized by cognitive dysfunction and movement abnormalities. A novel radiologic sign termed the "lentiform fork sign" has been identified in patients with UE and metabolic acidosis. This sign manifests as bilateral symmetrical hyperintensities in the basal ganglia, bordered by a hyperintense rim on magnetic resonance imaging (MRI), particularly on T2-weighted and fluid-attenuated inversion recovery (FLAIR) sequences. The basal ganglia, highly metabolically active structures, are prone to damage from metabolic derangements, toxins, and systemic conditions. We present a 56-year-old male with a history of chronic kidney disease and diabetes mellitus, maintained on hemodialysis and metformin. The patient presented with acute neurological symptoms, including slurred speech, left-sided weakness, and dysarthria. Brain MRI revealed bilateral basal ganglia hyperintensities on T2-weighted images, consistent with the lentiform fork sign. Laboratory investigations showed elevated serum urea and metabolic acidosis, suggestive of uremic encephalopathy. The patient's condition improved following dialysis, leading to partial resolution of neurological symptoms.

Keywords: basal ganglia hyperintensities; case report; lentiform fork sign; stoke; uremic encephalopathy.

Figure 1. Axial T2-weighted FLAIR imaging of the brain

Axial T2-weighted fluid-attenuated inversion recovery (FLAIR) imaging demonstrates bilateral symmetrical swollen lentiform nuclei with a hyperintense rim delineating the lentiform nucleus with a typical fork-like appearance representing the “lentiform fork" sign (arrow).

Figure 2. DWI and ADC map images of the brain

Diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC) map images demonstrate bilateral mild high signal intensity with no diffusion restriction.