Bohnen Nicolaas I, Frey Kirk A
Department of Neurology and Radiology, University of Pittsburgh School of Medicine, 3471 Fifth Avenue, Suite 811, Pittsburgh, PA 15213, USA.
Neuroimaging Clin N Am. 2003 Nov;13(4):791-803. doi: 10.1016/s1052-5149(03)00096-0.
PET imaging provides the means to study neurochemical, hemodynamic, or metabolic processes that underlie movement disorders in vivo. Because the extent of presynaptic nigrostriatal dopaminergic denervation can be quantified in PD even at an early or preclinical stage of the disease, PET imaging may allow the selection of at-risk subjects for neuroprotective intervention trials. These techniques may also provide markers to follow progression of disease or evaluate the effects of neurorestorative interventions in patients who have more advanced disease. PET is expected to play an increasing role in the selection of patients who have PD for deep brain stimulation. Dopaminergic studies may have a limited clinical role in the diagnosis of patients who have symptoms that suggestive of PD yet do not respond to typical dopaminergic drugs, such as patients who have vascular parkinsonism or ET with mild resting tremor who may have normal dopaminergic innervation. The differential diagnosis between PD and multiple system atrophy, progressive supranuclear palsy, or corticobasal degeneration is not yet clearly established by PET, but combined pre- and postsynaptic dopaminergic imaging may be able to distinguish early idiopathic PD from atypical parkinsonian disorders, in general. Huntington's chorea is characterized by more prominent striatal dopamine receptor loss, whereas nigrostriatal denervation is present to a lesser degree. Patients who have TS may have enhanced synaptic dopamine release in the putamen. Functional imaging studies have generally failed to demonstrate nigrostriatal denervation in essential tremor or idiopathic dystonia. Studies have shown striatal dopamine receptor loss in selected subtypes of dystonic patients. In conclusion, it is expected that PET will help us to better understand the pathophysiology of movement disorders, increase the diagnostic accuracy, allow preclinical diagnosis, monitor disease progression, and evaluate the efficacy of therapeutic agents. Pharmacologic radioligand displacement studies and the development of new nondopaminergic ligands may further aid in the unraveling of cerebral mechanisms that underlie movement disorders.
正电子发射断层扫描（PET）成像提供了在体内研究导致运动障碍的神经化学、血流动力学或代谢过程的手段。由于即使在帕金森病（PD）的早期或临床前期阶段，也可以对突触前黑质纹状体多巴胺能去神经支配的程度进行量化，PET成像可能有助于选择有风险的受试者进行神经保护干预试验。这些技术还可以提供标志物，以跟踪疾病进展或评估对病情更严重患者进行神经修复干预的效果。预计PET在为PD患者选择进行深部脑刺激方面将发挥越来越大的作用。多巴胺能研究在诊断有PD症状但对典型多巴胺能药物无反应的患者时，临床作用可能有限，例如患有血管性帕金森综合征或伴有轻度静止性震颤的特发性震颤（ET）患者，其多巴胺能神经支配可能正常。PET尚未明确建立PD与多系统萎缩、进行性核上性麻痹或皮质基底节变性之间的鉴别诊断，但一般来说，联合突触前和突触后多巴胺能成像可能能够区分早期特发性PD与非典型帕金森病。亨廷顿舞蹈病的特征是纹状体多巴胺受体损失更为明显，而黑质纹状体去神经支配程度较轻。患有抽动秽语综合征（TS）的患者可能在壳核中突触多巴胺释放增强。功能成像研究一般未能在原发性震颤或特发性肌张力障碍中证实黑质纹状体去神经支配。研究表明，在特定亚型的肌张力障碍患者中存在纹状体多巴胺受体损失。总之，预计PET将帮助我们更好地理解运动障碍的病理生理学，提高诊断准确性，实现临床前诊断，监测疾病进展，并评估治疗药物的疗效。药理放射性配体置换研究和新的非多巴胺能配体的开发可能会进一步有助于揭示运动障碍背后的脑机制。
