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CC BY 4.0 · Arq Neuropsiquiatr 2024; 82(08): s00441787763
DOI: 10.1055/s-0044-1787763
Images in Neurology

“Lentiform fork sign” in uremic striatopallidal syndrome: a rare cause of parkinsonism

“Sinal da forquilha lentiforme” na síndrome estriado-palidal urêmica: uma causa rara de parkinsonismo
Trajano Aguiar Pires Gonçalves 
1   Universidade de São Paulo, Faculdade de Medicina de Ribeirão Preto, Departamento de Neurociências e Ciências Comportamentais, Ribeirão Preto SP, Brazil.
,
Pedro José Tomaselli 
1   Universidade de São Paulo, Faculdade de Medicina de Ribeirão Preto, Departamento de Neurociências e Ciências Comportamentais, Ribeirão Preto SP, Brazil.
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An 88-year-old diabetic man, with end-stage chronic kidney disease, on dialysis, presented with nausea and diarrhea for 2 days. After this period, the patient's family sought emergency care due to a significant and acute reduction in movement, dysphonia, and dysphagia. His physical examination was consistent with akinetic-rigid parkinsonian syndrome. A brain magnetic resonance imaging scan was performed, and the lentiform fork sign was identified ([Figure 1]), which, associated with metabolic acidosis, corroborated the diagnosis of uremic striatopallidal syndrome.

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Figure 1 Head computed tomography (CT) scan showing symmetrical hypodensity in the lentiform nuclei bilaterally (A). Brain magnetic resonance imaging (MRI) scan in fluid-attenuated inversion recovery (FLAIR) (B) and T2-weighted (C) sequences demonstrateing hyperintensity in the lentiform nuclei bilaterally. The white arrows show T2 and FLAIR hyperintensity in the white matter surrounding the lentiform, representing edema in the internal and external capsules. This finding forms the basis of the fork of the “lentiform fork sign”. Facilitated diffusion can be seen on the diffusion-weighted imaging (DWI) (D) and apparent diffusion coefficient (ADC) (E) sequences. Illustrative representation of a fork (F).

Uremic striatopallidal syndrome is a rare cerebral complication of metabolic acidosis. It may present in the form of chorea or, more commonly, acute parkinsonism.[1]

Authors' Contributions

TAPG, PJT: writing and review of the manuscript. All authors approved the final version of the manuscript and agree to be responsible for all aspects of the work.




Publication History

Received: 28 February 2024

Accepted: 06 April 2024

Article published online:
08 July 2024

© 2024. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution 4.0 International License, permitting copying and reproduction so long as the original work is given appropriate credit (https://creativecommons.org/licenses/by/4.0/)

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Bibliographical Record
Trajano Aguiar Pires Gonçalves, Pedro José Tomaselli. “Lentiform fork sign” in uremic striatopallidal syndrome: a rare cause of parkinsonism. Arq Neuropsiquiatr 2024; 82: s00441787763.
DOI: 10.1055/s-0044-1787763