Marek M, Paus S, Allert N, Mädler B, Klockgether T, Urbach H, Coenen V A
Department of Neurology, Bonn University Medical Center, Sigmund-Freud-Str. 25, 53105, Bonn, Germany,
J Neurol. 2015 Jan;262(1):54-8. doi: 10.1007/s00415-014-7503-8. Epub 2014 Oct 7.
Focal lesions of brainstem, thalamus, and subcortical white matter may cause movement disorders that are clinically indistinguishable from cerebellar symptoms. It is suspected that ataxia in these cases is due to damage of efferent or afferent pathways of the cerebellum. However, the precise anatomical correlate often remains undefined. We used deterministic diffusion tensor magnetic resonance imaging (DTI) tractography to study the anatomical relationship between lesions causing ataxia and efferent cerebellar pathways. Study subjects were six male patients with focal lesions of different etiology (demyelination, hemorrhage, ischemia, neoplasm) outside the cerebellum. Five patients had cerebellar-like ataxia with prominent contralateral upper limb involvement. One patient with an almost midline mesencephalic lesion had a symmetrical ataxic syndrome. We used 3T MRI (Intera, Philips Medical Systems, Best, Netherlands) and DTI tractography (32 directions, StealthViz DTI, Medtronic Navigation, Louisville, USA) to delineate the dentato-rubro-thalamo-cortical tract (DRT). In all patients, tractography demonstrated focal lesions affecting the DRT in different locations. We conclude that in vivo mapping of cerebral pathways using DTI tractography in patients with focal extracerebellar brain lesions may provide direct evidence of circumscribed damage to the DRT, causing unilateral cerebellar-like ataxia. Also, a unilateral mesencephalic lesion at the level of the crossing of the DRT may cause bilateral ataxia.
脑干、丘脑及皮质下白质的局灶性病变可导致运动障碍，临床上与小脑症状难以区分。据推测，这些病例中的共济失调是由于小脑传出或传入通路受损所致。然而，确切的解剖学关联往往仍不明确。我们使用确定性扩散张量磁共振成像（DTI）纤维束成像技术来研究导致共济失调的病变与小脑传出通路之间的解剖学关系。研究对象为6名小脑外不同病因（脱髓鞘、出血、缺血、肿瘤）的局灶性病变男性患者。5例患者出现类似小脑性共济失调，对侧上肢受累明显。1例中脑近中线病变患者出现对称性共济失调综合征。我们使用3T磁共振成像（Intera，飞利浦医疗系统公司，荷兰贝斯特）和DTI纤维束成像技术（32个方向，StealthViz DTI，美敦力导航公司，美国路易斯维尔）来描绘齿状核-红核-丘脑-皮质束（DRT）。在所有患者中，纤维束成像均显示不同部位的局灶性病变影响了DRT。我们得出结论，在患有小脑外局灶性脑病变的患者中，使用DTI纤维束成像对脑通路进行活体映射，可能为DRT的局限性损伤导致单侧小脑样共济失调提供直接证据。此外，DRT交叉水平的单侧中脑病变可能导致双侧共济失调。
