Hahn-Barma V, Deweer B, Dürr A, Dodé C, Feingold J, Pillon B, Agid Y, Brice A, Dubois B
Fédération de Neurologie and INSERM U.289, Hôpital de la Salpêtrière, Paris, France.
J Neurol Neurosurg Psychiatry. 1998 Feb;64(2):172-7. doi: 10.1136/jnnp.64.2.172.
Huntington's disease is a neurodegenerative disorder due to an excessive number of CAG repeats in the IT15 gene on chromosome 4. The first symptoms are typically choreic movements or psychiatric disorders, whereas global cognitive decline generally becomes obvious later. This study was aimed at detecting early subtle cognitive deficits in asymptomatic gene carriers.
As part of the testing procedure for predictive diagnosis of Huntington's disease, 91 asymptomatic at risk candidates had a neuropsychological examination, evaluating global efficiency, attention, memory (Wechsler memory scale and California verbal learning test), and executive functions.
The groups of carriers (n=42) and non-carriers (n=49) differed only on a few memory variables. When we considered the group of gene carriers as a whole, significant correlations emerged between the number of CAG repeats and (a) performance on several tests of executive functions, and (b) performance on the hard pairs associates of the Wechsler memory scale. Further analysis of performance on this memory subtest led to the division of the group of carriers into two subgroups, without any overlap. The performance of subjects without cognitive deficits (n=32) was similar to that of non-carriers on all tests. The subjects with cognitive deficits (n=10) differed from both carriers without cognitive deficits and non-carriers over a wide array of variables measuring executive functions and memory. Moreover, qualitative aspects of the performance of carriers with cognitive deficits in the California verbal learning test closely resembled those of patients diagnosed as having Huntington's disease.
This suggests that these subjects already have Huntington's disease, despite a total lack of motor and psychiatric signs. An ongoing follow up study is testing the prediction that they will develop the full range of symptoms of the disease earlier than carriers without cognitive deficits.
亨廷顿舞蹈症是一种神经退行性疾病，由4号染色体上IT15基因中过多的CAG重复序列所致。最初症状通常为舞蹈样动作或精神障碍，而全面的认知衰退一般在后期才会变得明显。本研究旨在检测无症状基因携带者早期细微的认知缺陷。
作为亨廷顿舞蹈症预测性诊断检测程序的一部分，91名无症状的高危受试者接受了神经心理学检查，评估整体效能、注意力、记忆力（韦氏记忆量表和加利福尼亚言语学习测验）以及执行功能。
携带者组（n = 42）和非携带者组（n = 49）仅在少数记忆变量上存在差异。当我们将基因携带者组作为一个整体考虑时，CAG重复序列的数量与（a）几项执行功能测试的表现，以及（b）韦氏记忆量表中硬对联想测试的表现之间出现了显著相关性。对该记忆子测试表现的进一步分析导致携带者组被分为两个亚组，没有任何重叠。无认知缺陷的受试者（n = 32）在所有测试中的表现与非携带者相似。有认知缺陷的受试者（n = 10）在一系列测量执行功能和记忆的变量上与无认知缺陷的携带者和非携带者均存在差异。此外，有认知缺陷的携带者在加利福尼亚言语学习测验中的表现的定性方面与被诊断为患有亨廷顿舞蹈症的患者非常相似。
这表明这些受试者尽管完全没有运动和精神症状，但已经患有亨廷顿舞蹈症。一项正在进行的随访研究正在检验这样的预测，即他们将比无认知缺陷的携带者更早出现该疾病的全部症状。
