Bulakbasi N, Kocaoglu M, Tayfun C, Ucoz T
Department of Radiology, Gulhane Military Medical Academy, Ankara, Turkey.
AJNR Am J Neuroradiol. 2006 Oct;27(9):1983-6.
Reversible lesions in the splenium of the corpus callosum (SCC), caused by various agents such as influenza, rotavirus, Escherichia coli, mumps, and adenovirus, were previously defined in a handful of cases. We present 5 cases with transient diffusion restriction of the SCC associated with influenza A virus infection.
Five patients with influenza-associated encephalitis/encephalopathy and sudden-onset neurologic symptoms following a prodromal flulike episode were examined by MR and diffusion-weighted imaging (DWI).
Three patients, who had drowsiness and new-onset convulsions, recovered spontaneously without any medication. In the other 2 seizure-free patients, 1 had trigeminal neuralgia and headache and the other had facial numbness and left upper monoparesis. All patients had round well-defined ovoid hyperintense splenial lesions (14.94 +/- 1.87 mm) on DWI with a significantly low apparent diffusion coefficient (ADC) of 0.41 +/- 0.05 x 10(-3) mm(2)/s compared with 0.84 +/- 0.01 x 10(-3) mm(2)/s of normal-appearing white matter. In the patient with a motor deficit, additional lesions were found in the cerebral deep white matter. The high signal intensity of the splenial and deep white matter lesions on DWI completely disappeared on follow-up studies, and ADC values also improved, returning to those of normal-appearing white matter on days 8-11. Clinically, all patients completely recovered on days 4-9.
A transient lesion of the SCC is a significant but nonspecific finding. It is probably due to edematous and/or inflammatory changes of the SCC. It may be the only detectable change in patients with good prognosis, indicating a clinically mild form of encephalitis/encephalopathy.
由流感、轮状病毒、大肠杆菌、腮腺炎病毒和腺病毒等多种病原体引起的胼胝体压部（SCC）可逆性病变，此前仅在少数病例中有过报道。我们报告5例与甲型流感病毒感染相关的SCC短暂性弥散受限病例。
对5例流感相关的脑炎/脑病患者进行了磁共振成像（MR）和弥散加权成像（DWI）检查，这些患者在流感样前驱症状后出现突发神经系统症状。
3例出现嗜睡和新发惊厥的患者未经任何药物治疗即自发康复。另外2例无癫痫发作的患者，1例有三叉神经痛和头痛，另1例有面部麻木和左上半身轻瘫。所有患者在DWI上均可见圆形边界清晰的椭圆形高信号胼胝体病变（14.94±1.87 mm），表观扩散系数（ADC）显著降低，为0.41±0.05×10⁻³ mm²/s，而正常白质的ADC值为0.84±0.01×10⁻³ mm²/s。在有运动功能障碍的患者中，脑深部白质还发现了其他病变。DWI上胼胝体和深部白质病变的高信号强度在随访研究中完全消失，ADC值也有所改善，在第8 - 11天恢复至正常白质水平。临床上，所有患者均在第4 - 9天完全康复。
SCC的短暂性病变是一个重要但非特异性的发现。可能是由于SCC的水肿和/或炎症改变所致。它可能是预后良好患者唯一可检测到的变化，提示临床上为轻度脑炎/脑病形式。
