Cerebrotendinous xanthomatosis (CTX) is a rare metabolic disorder caused by mutations in the CYP27A1 gene, leading to cholestanol accumulation in various tissues, including peripheral nerves. Polyneuropathy is an underrecognized feature with considerable variability in clinical presentation and neurophysiological findings in CTX. This review assesses the prevalence, clinical manifestations, and diagnostic methodologies of polyneuropathy in CTX, exploring its underlying mechanisms and potential treatment outcomes. A literature review was conducted using PubMed, Embase, and the Virtual Health Library databases with search terms related to CTX and polyneuropathy. A total of 892 articles were initially identified, with 59 selected for in-depth analysis. The review focused on studies examining peripheral nerve involvement in CTX, including nerve conduction studies, electromyography, and nerve ultrasound. Polyneuropathy in CTX was observed in 50% to 77.7% of patients across multiple case series. Neurophysiological findings varied, with reports of axonal, demyelinating, and mixed polyneuropathies. Clinical presentation included lower limb atrophy, pes cavus, and distal weakness, with sensory symptoms less frequently reported. Treatment with chenodeoxycholic acid (CDCA) showed potential in improving nerve conduction parameters, although the response was variable and dependent on the timing of intervention. Polyneuropathy in CTX presents significant diagnostic challenges due to its heterogeneous presentation and varying neurophysiological findings. Early recognition and intervention are crucial for improving patient outcomes. Peripheral nerve ultrasound is a promising diagnostic tool, complementing traditional neurophysiological assessments. Further research is needed to standardize protocols and explore the full therapeutic potential of CDCA in managing CTX-related polyneuropathy.

Background Arquivos de Neuro-Psiquiatria (ANP), the official journal of Academia Brasileira de Neurologia (ABN, Brazilian Academy of Neurology), celebrated 80 years in 2023. Objective To analyze the publication trends, authorship, and editorial patterns of the first 20 volumes of ANP. Methods We analyzed the first 20 volumes of ANP, published from 1943 to 1962. The data were tabulated independently by two blinded researchers and cross-verified. Results Oswaldo Lange was the chief editor, and, from 1943 to 1962, 20 volumes, 79 issues, 2 supplements, and 885 articles were published. We analyzed 509 articles (and excluded non-research papers). We found 905 authors (1.78 authors/article), and only 3.75% were women. Horacio Martins Canelas, Rolando Ângelo Tenuto, and Paulo Pinto Pupo were the most prolific authors. There were 326 papers on neurology, 83 on neurosurgery, 88 on psychiatry, and 12 on basic research. A comparison between the first 10 and second 10 volumes disclosed a significant difference in the fields of the articles: a progressive decrease in papers on psychiatry and an increase in those on neurology and basic science (p = 0.005). There was also a significant decrease in the total number of published articles in the second 10 volumes (p = 0.001), and a higher number of citations per article (p = 0.014), but no difference in the number of pages (mean number in the original articles: 11.9 ± 6.7 pages). Although most articles came from Southeastern Brazil (74%) and were written in Portuguese (84%), 91 were foreign. Conclusion The first 20 volumes marked the establishment of ANP in the post-World War II era. Most papers were written in Portuguese and included international contributions from Egas Moniz, Barraquer-Bordas, Bing, Denny-Brown and Wartenberg, for example.

Arquivos de Neuro-Psiquiatria (ANP) celebrated 80 years in 2023. We have previously evaluated the publication trends throughout the first 20 years. To analyze the publication trends, authorship, and editorial patterns of the volumes 21 to 40 of ANP (1983–1962). Data were tabulated independently by two blinded researchers and cross-verified by independent researchers and automated data extraction technology (Python script). From 1963 to 1982, 20 volumes, 80 issues, and 904 articles were published. In 1970, ANP became the official journal of Academia Brasileira de Neurologia (ABN, the Brazilian Academy of Neurology). We analyzed 795 articles (and excluded non-research papers). Compared to the first 20 years, there was a significant increase in the total number of authors per article (2.73; p < 0.05), a significant increase in the percentage of female authors (to 10.96%; p < 0.05), and a decrease in the number of pages per article (p < 0.05). Antonio Spina-França, Walter Carlos Pereira, and Michel Pierre Lison were the most prolific authors. Most of the articles were on the topics of Neurology/Child Neurology, with a decrease in the percentage of Psychiatry papers and an increase in Basic Research contributions. There was also a linear increase in the total number of articles from 1963 to 1982, as detected by regression analysis (R² = 0.86; p < 0.0001). Most of the articles were written in Portuguese and by authors from Southeastern Brazil (71.1%). The years 1963 to 1982 marked the resilience of ANP during the tempestuous years of the Brazilian Military dictatorship, coinciding with an increased split between the Neurology and Psychiatry fields, the appearance of clinical trials and large case series, and a greater development in the understanding of neuroinfectious diseases. Conceptualization: RFR, FAAG; Data curation: RFR, FRDGJ, ADB, EDSL, NFAF, AKRS, FAFJ, JVUS, FAAG; Formal analysis: RFR, FRDGJ, ADB, EDSL, NFAF, AKRS, FAFJ, JVUS; Investigation: RFR, FRDGJ, ADB, EDSL, NFAF, AKRS, FAFJ, JVUS, FAAG; Methodology: RFR, FAAG; Project administration: RFR, FAAG; Supervision: FAAG; Validation: RFR, FRDGJ, ADB, FAAG; Visualization: RFR, FRDGJ, ADB, FAAG; Writing – original draft: RFR, FAAG; Writing – review & editing: RFR, FAAG. Data will be available upon request to the corresponding author. Editor-in-Chief: Hélio A. G. Teive (https://orcid.org/0000-0003-2305-1073). Associate Editor: Eliasz Engelhardt (https://orcid.org/0000-0003-4168-1992). Received: 26 August 2025 Accepted: 08 October 2025 Article published online: 11 March 2026 © 2026. 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/) Thieme Revinter Publicações Ltda. Rua Rego Freitas, 175, loja 1, República, São Paulo, SP, CEP 01220-010, Brazil

Introduction/Aims: Cerebrotendinous xanthomatosis (CTX) is a rare autosomal recessive disorder caused by variants in the CYP27A1 gene, resulting in cholestanol accumulation in various tissues, including peripheral nerves. Polyneuropathy is common but often under‐recognized in CTX. This study aimed to evaluate the cross‐sectional area (CSA) of peripheral nerves in CTX. Methods: Six genetically confirmed CTX patients underwent clinical, electrophysiological, and ultrasonographic evaluations. Clinical severity was assessed using the Scale for the Assessment and Rating of Ataxia (SARA) and the Polyneuropathy Disability (PND) score. Nerve ultrasound was performed at standardized sites of the median, ulnar, tibial, and sural nerves, and at the supraclavicular brachial plexus. CSA values were compared with healthy controls. Results: Nerve conduction studies (NCS) identified demyelinating polyneuropathy in three patients. However, ultrasound showed nerve enlargement in all six, including those with normal NCS. The supraclavicular brachial plexus was enlarged in every patient. In 5 adult patients, enlargement was most consistently observed in the median nerve (4 at the wrist and forearm; 5 at the cubital fossa and upper arm), the ulnar nerve at the upper arm (5), and the fibular nerve at the fibular head (4). Discussion: This study demonstrates that nerve ultrasound can detect peripheral nerve enlargement in CTX, even in preclinical stages of polyneuropathy. Enlargement of peripheral nerves may be a sensitive marker of disease severity and peripheral nerve involvement. The role of nerve ultrasound as a diagnostic tool in CTX is promising, and future longitudinal studies are needed to determine its value in disease monitoring.