Department of Neurology, The University of Texas Health Science Center McGovern Medical School, Houston, TX.
Department of Interventional and Diagnostic Radiology, The University of Texas Health Science Center, McGovern Medical School, Houston, TX.
J Neuroimaging. 2018 Nov;28(6):596-600. doi: 10.1111/jon.12531. Epub 2018 Jun 12.
In 1948, Paul Yakovlev described an additional limbic circuit located basolateral to James Papez's circuit (1937) and included orbitofrontal cortex, amygdala, and dorsomedial nucleus of thalamus. This circuit is shown to be an important component of subcortical cognitive abilities. We aimed to demonstrate this circuit in a multiple sclerosis (MS) cohort using diffusion tensor imaging (DTI) and evaluate its role in MS-related cognitive impairment (CI).
We enrolled cognitively intact (n = 10) and impaired (n = 36) MS patients who underwent a comprehensive cognitive assessment; the minimal assessment of cognitive function in MS (MACFIMS) and structural magnetic resonance imaging. Correlation analyses between volumetric and DTI-derived values of the orbitofrontothalamic (OFT), amygdalothalamic tracts (ATTs), and dorsomedial nucleus of thalamus and CI index derived from MACFIMS were computed after adjustment for age, education, and lesion load.
We observed a consistent trend between CI index and bilateral dorsomedial nucleus' mean diffusivity (MD) (r = .316; P = .02), left OFT Fractional anisotropy (FA) (r = -.302; P = .02), MD (r = .380; .006), and radial diffusivities (RDs) (r = .432; P = .002), also with right ATT FA (r = -.475; P = .0006) and left ATT FA ( = -.487; P = .0005). After Bonferroni correction, correlations of left OFT RD and right and left ATT FA with CI were found to be significant.
Our study provides in vivo DTI delineation of Yakovlev's historical basolateral limbic circuit and establishes a role in MS-related CI. These findings may potentially pave the way for future clinical studies using targeted invasive and noninvasive neurostimulation modalities for CI in MS.
1948 年，Paul Yakovlev 描述了一个位于 James Papez 回路（1937 年）外侧的附加边缘回路，包括眶额皮质、杏仁核和丘脑背内侧核。该回路被证明是皮质下认知能力的重要组成部分。我们旨在使用弥散张量成像（DTI）在多发性硬化（MS）队列中显示该回路，并评估其在 MS 相关认知障碍（CI）中的作用。
我们招募了认知正常（n=10）和受损（n=36）的 MS 患者，他们接受了全面的认知评估；最小评估认知功能在多发性硬化症（MACFIMS）和结构磁共振成像。在调整年龄、教育和病变负荷后，计算了眶额丘脑（OFT）、杏仁核丘脑束（ATT）和丘脑背内侧核的容积和 DTI 衍生值与 MACFIMS 衍生的 CI 指数之间的相关性分析。
我们观察到 CI 指数与双侧丘脑背内侧核的平均弥散度（MD）（r =.316；P =.02）、左侧 OFT 各向异性分数（FA）（r = -.302；P =.02）、MD（r =.380；P =.006）和径向弥散度（RD）（r =.432；P =.002）之间存在一致的趋势，也与右侧 ATT FA（r = -.475；P =.0006）和左侧 ATT FA（r = -.487；P =.0005）相关。经过 Bonferroni 校正后，发现左侧 OFT RD 和右侧和左侧 ATT FA 与 CI 的相关性具有统计学意义。
我们的研究提供了 Yakovlev 历史上的基底边缘回路的活体 DTI 描绘，并确立了它在 MS 相关 CI 中的作用。这些发现可能为未来使用靶向侵袭性和非侵袭性神经刺激模式治疗 MS 相关 CI 的临床研究铺平道路。
