Gerwig Marcus, Hajjar Karim, Dimitrova Albena, Maschke Matthias, Kolb Florian P, Frings Markus, Thilmann Alfred F, Forsting Michael, Diener Hans Christoph, Timmann Dagmar
Department of Neurology, University of Duisburg-Essen, D-45147 Essen, Germany.
J Neurosci. 2005 Apr 13;25(15):3919-31. doi: 10.1523/JNEUROSCI.0266-05.2005.
In the present study, timing of conditioned eyeblink responses (CRs) was investigated in cerebellar patients and age-matched controls using a standard delay paradigm. Findings were compared with previously published data of CR incidences in the same patient population (Gerwig et al., 2003; Timmann et al., 2005). Sixteen patients with pure cortical cerebellar degeneration (spinocerebellar ataxia type 6 and idiopathic cerebellar ataxia), 14 patients with lesions within the territory of the superior cerebellar artery, and 13 patients with infarctions within the territory of the posterior inferior cerebellar artery were included. The affected cerebellar lobules and possible involvement of cerebellar nuclei were determined by three-dimensional magnetic resonance imaging (MRI) in patients with focal lesions (n = 27). Based on a voxel-by-voxel analysis, MRI lesion data were related to eyeblink conditioning data. CR incidence was significantly reduced, and CRs occurred significantly earlier in patients with cortical cerebellar degeneration and lesions of the superior cerebellum compared with controls. Incidence and timing of CRs was not impaired in patients with lesions restricted to the posterior and inferior cerebellum. Voxel-based MRI analysis revealed that cortical areas within the anterior lobe (Larsell lobule HV) were most significantly related to timing deficits, whereas reduced CR incidences were related to more caudal parts (lobule HVI) of the superior cerebellar cortex. The present data suggest that different parts of the superior cerebellar cortex may be involved in the formation of the stimulus association and appropriate timing of conditioned eyeblink responses in humans. Extracerebellar premotoneuronal disinhibition, however, is another possible explanation for changes in CR timing.
在本研究中，我们使用标准延迟范式，对小脑疾病患者和年龄匹配的对照组进行了条件性眨眼反应（CRs）的时间研究。将研究结果与之前发表的同一患者群体的CR发生率数据进行了比较（Gerwig等人，2003年；Timmann等人，2005年）。纳入了16例单纯皮质小脑变性患者（6型脊髓小脑共济失调和特发性小脑共济失调）、14例小脑上动脉供血区域病变患者以及13例小脑后下动脉供血区域梗死患者。对于局灶性病变患者（n = 27），通过三维磁共振成像（MRI）确定受影响的小脑小叶以及小脑核团可能的受累情况。基于逐体素分析，将MRI病变数据与眨眼条件反射数据相关联。与对照组相比，皮质小脑变性和小脑上部病变患者的CR发生率显著降低，且CR出现得明显更早。局限于小脑后部和下部病变的患者，其CR的发生率和时间并未受到损害。基于体素的MRI分析显示，前叶内的皮质区域（Larsell小叶HV）与时间缺陷最为显著相关，而CR发生率降低则与小脑上部皮质的更靠尾侧部分（小叶HVI）相关。目前的数据表明，小脑上部皮质的不同部分可能参与了人类条件性眨眼反应中刺激关联的形成和适当的时间控制。然而，小脑外运动前神经元去抑制是CR时间变化的另一种可能解释。
