Lesions in the splenium of the corpus callosum: Clinical and radiological implications

Background: Brain MRI may unexpectedly display abnormalities in splenium of the corpus callosum (SCC). However, the clinical implications of this lesion are unclear and are not always consistent with ischemic infarctions. We performed this study to clarify the clinical and radiological implications in patients with SCC lesions. Methods: We retrospectively reviewed consecutive patients with MRIreported SCC changes between 2009 and 2012. We analyzed clinical and radiological findings, etiologies, cognitive impairment, and clinical outcomes. Results: We found 30 patients (16 females; mean 50.5 years) who had SCC lesions on MRI. Confusion was the most common clinical finding in 50% of cases. Cerebral infarction was the most common etiology (50%). The most consistent SCC changes on MRI were low signal in T1WI, high signal on T2WI and FLAIR, and high signal on DWI. We classified SCC lesions into in situ SCC lesions (SCC only) and multiple (SCC plus) lesions for patients with multiple lesions. The clinical symptoms of SCC only lesions were relatively mild. Cognitive functions were evaluated by Mini Mental State Examination (MMSE) and clinical dementia rating (CDR) scale at the time of discharge and patients with SCC only lesions showed less impaired cognition compared with those with SCC plus lesions. Clinical outcomes were evaluated by the modified Rankin scale at 1 month and patients with SCC only lesions revealed good clinical outcomes compared with those with SCC plus lesions. Conclusions: MRI-reported SCC lesions may have heterogeneous etiologies and present with various symptoms. The clinical course and outcome are relatively good, particularly in small isolated and oval shaped SCC lesions. Neurology Asia 2014; 19(1) : 79 – 88 Address correspondence to: Seok-Beom Kwon, MD PhD, Department of Neurology, Hallym University College of Medicine,948-1, DaeRim1-Dong, YoengDeungPo-Gu, Seoul, 150-950, Korea. Tel: +82-02-829-5125, Fax: +82-2-847-1617, Email: [email protected] INTRODUCTION Splenium of the corpus callosum (SCC) abnormalities on magnetic resonance imaging (MRI) have been reported commonly and unexpectedly in many cases. Such SCC lesions are usually reversible and associated with many etiologies and clinical symptoms. However, the implications of an SCC abnormality are unclear and are not always associated with ischemic infarctions. Possible causes of SCC abnormalities include infarction, trauma, tumor, alcohol abuse, seizure, heat stroke, multiple sclerosis, epilepsy, drug intoxication, and panhypopituitarism. Many studies have been performed on this topic but most studies are limited to case reports of SCC lesions or special diseases and reviews with published cases. Thus, knowledge about SCC lesions is fragmentary. We undertook this study to evaluate clinical and radiologic findings, etiologies, cognitive impairment, and outcomes of patients with SCC abnormalities noted on brain MRI.