Funasaka Homare, Kanazawa Serika, Kamada Sachiko
Omagari Kosei Medical Center, Department of Neurology, Japan.
eNeurologicalSci. 2025 Jul 22;40:100578. doi: 10.1016/j.ensci.2025.100578. eCollection 2025 Sep.
FXTAS (Fragile X-associated tremor/ataxia syndrome) is characterized by typical clinical features, including tremor, cerebellar ataxia, parkinsonism, and the middle cerebellar peduncle (MCP) sign, which appears as T2 hyperintensity in the MCP on MRI. FXTAS is almost never considered in the context of cervical dystonia. However, this case demonstrates that FXTAS can initially present with cervical dystonia. A 59-year-old man presented with cervical dystonia, characterized by right lateral flexion, and sensory trick. His initial symptom was cervical tilt at age 54. At age 55, the patient developed an unsteady gait. The patient was unable to perform a tandem gait and stand up from a crouch, suggesting trunk ataxia, and exhibited lateral gaze nystagmus, which was indicative of a cerebellar disorder. MRI revealed MCP sign. Genetic testing confirmed FXTAS, revealing 90 CGG repeats in the (Fragile X Mental Retardation 1) gene. Notably, a pre-symptomatic MRI, incidentally acquired at the age of 52, retrospectively revealed the presence of the MCP sign. This suggests that, even when FXTAS initially presents as cervical dystonia, the MCP sign can remain a reliable diagnostic feature for early detection. This case highlights that early FXTAS may mimic idiopathic cervical dystonia and that considering FXTAS during the clinical evaluation of cervical dystonia can enable early diagnosis.
脆性X相关震颤/共济失调综合征（FXTAS）具有典型的临床特征，包括震颤、小脑共济失调、帕金森综合征以及小脑中脚（MCP）征，在磁共振成像（MRI）上表现为MCP的T2高信号。在颈部肌张力障碍的背景下，几乎从未考虑过FXTAS。然而，本病例表明FXTAS最初可能表现为颈部肌张力障碍。一名59岁男性出现以右侧侧屈和感觉技巧为特征的颈部肌张力障碍。他最初的症状是54岁时颈部倾斜。55岁时，患者出现步态不稳。患者无法进行串联步态和从蹲位站立，提示躯干共济失调，并表现出水平凝视眼震，这表明存在小脑疾病。MRI显示有MCP征。基因检测确诊为FXTAS，在脆性X智力低下1（FMR1）基因中发现90个CGG重复序列。值得注意的是，52岁时偶然进行的一次症状前MRI检查，回顾性显示存在MCP征。这表明，即使FXTAS最初表现为颈部肌张力障碍，MCP征仍是早期检测的可靠诊断特征。本病例强调早期FXTAS可能模仿特发性颈部肌张力障碍，在颈部肌张力障碍的临床评估中考虑FXTAS可实现早期诊断。
