Piras M R, Magnano I, Canu E D G, Paulus K S, Satta W M, Soddu A, Conti M, Achene A, Solinas G, Aiello I
Institute of Clinical Neurology, University of Sassari, Sassari, Italy.
J Neurol Neurosurg Psychiatry. 2003 Jul;74(7):878-85. doi: 10.1136/jnnp.74.7.878.
(1) To assess cognitive function and cerebral magnetic resonance imaging (MRI) involvement in relapsing-remitting multiple sclerosis; (2) to monitor disease evolution, cognitive dysfunction, and cerebral lesion burden over time (mean 8.5 year follow up period); (3) to study the relation between clinical, neuropsychological, and MRI data. On follow up assessment, visual and auditory oddball event related potentials (ERPs) were recorded as psychophysiological evaluation of cognitive status. Correlations between neuropsychological, MRI, and ERP data were also analysed.
Neuropsychological study assessed verbal and non-verbal IQ, deterioration index (DI) from WAIS subtests, conceptual reasoning, attention, verbal and visuospatial short-term and long term memory. MRI assessment detected presence of demyelinating lesions by using a semiquantitative method as well as cortical and subcortical atrophy over time.
Attention, short-term and long term visuospatial memory were mildly impaired at baseline and remained unaltered longitudinally. At retesting a significant worsening of verbal long term memory (p=0.023), DI presence (p=0.041) and the increase of supratentorial and subtentorial MRI lesions load (p=0.001) emerged. Expanded disability status scale score correlated significantly with total lesion burden at both evaluations (p=0.043 and p=0.024 respectively). Temporal, occipital, and frontal horn lesions as well as cortical atrophy correlated significantly with attention and memory tests at baseline. Follow up assessment revealed significant correlation between cortical atrophy and attention as well as visuospatial short-term memory; spatial long term memory correlated significantly with lesions in body of lateral ventricle and frontal lobe. ERP study showed P300 latency abnormalities in 75% of patients, involving specifically more visual P300 (58.4 % of cases) than auditory wave (41.6 %). Visual P300 latency and amplitude correlated significantly with DI and auditory P300 latency with frontal horn and brain stem lesions.
These findings revealed mild cognitive impairment in MS patients particularly consistent with slowing information processing over time. Increased MRI lesions do not correlate with the clinical course of the disease and cognitive deficit evolution. Thus, cognitive dysfunction could be related to disease peculiarity and not to the time course. Correlations between P300, neuropsychological, and MRI findings provide further information about ERP application to examine cognitive impairment in MS and probably to investigate their neural origin.
（1）评估复发缓解型多发性硬化症患者的认知功能及脑磁共振成像（MRI）表现；（2）监测疾病进展、认知功能障碍及脑病变负荷随时间的变化（平均随访期8.5年）；（3）研究临床、神经心理学及MRI数据之间的关系。在随访评估中，记录视觉和听觉Oddball事件相关电位（ERP），作为认知状态的心理生理学评估。还分析了神经心理学、MRI及ERP数据之间的相关性。
神经心理学研究评估言语和非言语智商、韦氏成人智力量表（WAIS）各分测验的衰退指数（DI）、概念推理、注意力、言语和视觉空间短期及长期记忆。MRI评估采用半定量方法检测脱髓鞘病变的存在，以及随时间变化的皮质和皮质下萎缩情况。
基线时注意力、短期及长期视觉空间记忆轻度受损，且纵向未发生改变。复测时，言语长期记忆显著恶化（p=0.023）、出现DI（p=0.041）以及幕上和幕下MRI病变负荷增加（p=0.001）。在两次评估中，扩展残疾状态量表评分均与总病变负荷显著相关（分别为p=0.043和p=0.024）。颞叶、枕叶和额角病变以及皮质萎缩在基线时与注意力和记忆测试显著相关。随访评估显示，皮质萎缩与注意力以及视觉空间短期记忆之间存在显著相关性；空间长期记忆与侧脑室体部和额叶病变显著相关。ERP研究显示，75%的患者存在P300潜伏期异常，其中视觉P300异常（58.4%的病例）比听觉波异常（41.6%）更为常见。视觉P300潜伏期和波幅与DI显著相关，听觉P300潜伏期与额角和脑干病变相关。
这些发现揭示了MS患者存在轻度认知障碍，尤其与随着时间推移信息处理速度减慢一致。MRI病变增加与疾病临床进程及认知缺陷演变无关。因此，认知功能障碍可能与疾病特性有关，而非与病程有关。P300、神经心理学及MRI结果之间的相关性为ERP应用于检查MS患者认知障碍及可能研究其神经起源提供了进一步信息。
