Coulette Sarah, Lecler Augustin, Le Cossec Chloé, Philibert Manon, Gaymard Bertrand, Delmaire Christine, Charbonneau Frédérique, Torcello Jean-Marc, Brandel Jean-Philippe, Wenta Justine, Gueguen Antoine, Desjardins Clément
Department of Neurology, Hôpital Fondation Rothschild, Paris, France.
Department of Radiology, Hôpital Fondation Rothschild, Paris, France.
Eur J Neurol. 2025 Jun;32(6):e70228. doi: 10.1111/ene.70228.
Spinocerebellar ataxia type 27B (SCA27B), caused by a GAA repeat expansion in FGF14, is a recently described genetic etiology of idiopathic late-onset cerebellar ataxia (ILOCA). Downbeat nystagmus (DBN) is increasingly recognized as a clinical hallmark of this condition. We aimed to assess the diagnostic value of video-oculography (VOG) in detecting SCA27B and its role in monitoring response to 4-aminopyridine (4-AP) in a real-world clinical setting.
We retrospectively analyzed patients with ILOCA referred to Fondation Rothschild Hospital (Paris, France) from February 2023 to January 2024. All underwent clinical, MRI, and VOG assessments, with genetic testing for FGF14-GAA expansions. Clinical and oculomotor features of carriers (≥ 200 repeats) and non-carriers were compared. A subset of symptomatic carriers received 4-AP and were evaluated at baseline, 2 months, and 8 months using the Scale for the Assessment and Rating of Ataxia (SARA) and VOG.
Twelve of 34 tested patients (35%) were FGF14-GAA expansion carriers. DBN was significantly more frequent in carriers than in non-carriers (92% vs. 33%, p = 0.003), often associated with gaze-evoked nystagmus (75% vs. 19%, p = 0.005). MRI did not distinguish carriers from non-carriers. Of the nine patients treated, all reported enhanced balance, which is corroborated by the improvement in the SARA score from a median of 5.5-3 at 2 months (p = 0.015), with sustained benefit at 8 months.
VOG is a key diagnostic tool for detecting DBN, which is strongly associated with SCA27B, facilitating targeted genetic testing. 4-AP is an effective symptomatic treatment.
27B型脊髓小脑共济失调（SCA27B）由FGF14基因中的GAA重复序列扩增引起，是特发性迟发性小脑共济失调（ILOCA）最近被描述的遗传病因。下跳性眼球震颤（DBN）越来越被认为是这种疾病的临床标志。我们旨在评估视频眼震图（VOG）在检测SCA27B中的诊断价值及其在真实临床环境中监测对4-氨基吡啶（4-AP）反应的作用。
我们回顾性分析了2023年2月至2024年1月转诊至法国巴黎罗斯柴尔德基金会医院的ILOCA患者。所有患者均接受了临床、MRI和VOG评估，并进行了FGF14-GAA扩增的基因检测。比较了携带者（≥200次重复）和非携带者的临床和动眼神经特征。一部分有症状的携带者接受了4-AP治疗，并在基线、2个月和8个月时使用共济失调评估和评分量表（SARA）和VOG进行评估。
34名接受检测的患者中有12名（35%）是FGF14-GAA扩增携带者。携带者中DBN的发生率显著高于非携带者（92%对33%，p = 0.003），且常伴有凝视诱发的眼球震颤（75%对19%，p = 0.005）。MRI无法区分携带者和非携带者。在接受治疗的9名患者中，所有患者均报告平衡能力增强，SARA评分从2个月时的中位数5.5提高到3（p = 0.015），并在8个月时持续受益，这证实了这一点。
VOG是检测DBN的关键诊断工具，DBN与SCA27B密切相关，有助于进行有针对性的基因检测。4-AP是一种有效的对症治疗方法。
