Introduction: Early brain injury following aneurismal subarachnoid hemorrhage (SAH) results from the acute rise of intracranial pressure and is recognized as one of the most important factors that influences the outcome of the patients. The corpus callosum is reported to be vulnerable to the intracranial hypertension. Therefore, we hypothesized that the corpus callosum is one of the most frequently damaged part of the brain after severe subarachnoid hemorrhage. The aim of this study is to investigate the frequency of the callosal lesions following SAH and the association between the callosal lesions, and the severity on admission and outcome.
Methods: 56 patients who underwent surgery for aneurismal subarachnoid hemorrhage were reviewed retrospectively. The severity was evaluated with the World Federation of Neurological Societies (WFNS) grade on admission. Outcome was evaluated with Glasgow Outcome Scale (GOS) 30 days after the onset. MRI including DWI was performed around 7 days following surgery. The callosal lesion was defined as the high-intensity lesion in the corpus callosum on DWI.
Results: Nine patients (16%) had the callosal lesions. The distribution of the high-intensity lesions were as follows: 6 cases in the splenium, 1 case in the genu, 2 cases in the diffuse area of the corpus callosum. DWI positive lesions were detected more frequently in the patients with high-grade SAH, WFNS grade 4 and 5 (44% versus 17%, p=0.086). There was a significantly higher frequency of poor outcomes, defined as SD, VS and D on GOS, in DWI positive patients than the DWI negative patients (33% versus 4.3%, p=0.025). The clinical outcome of both of patients with diffuse callosal lesions were poor.
Conclusions: The callosal lesions secondary to SAH associated with the poor clinical grade on admission and the poor clinical outcome.
Patient Care: Although the corpus callosum can be damaged after SAH, this abnormality is often overlooked. If the callosal lesion is useful to predict the outcome, the surgical indication and treatment strategy for the SAH patients with the callosal lesions can be changed. Further study should be performed to clarify whether the callosal lesions after SAH is useful to predict the outcome.
Learning Objectives: The callosal lesions after SAH are not recognized well. Our aim is to investigate the frequency of the callosal lesions following SAH and the association between the callosal lesions, and the severity on admission and outcome.