Correlation between characteristics of intracranial lesions and level of cognitive function in patients with an initial diagnosis of brain metastases

Objective: To investigate the correlation between the characteristics of intracranial lesions and the level of cognitive function in patients with an initial diagnosis of brain metastases. Methods: A retrospective analysis was performed in 51 patients with an initial diagnosis of brain metastases who were admitted to The Second Hospital Affiliated to Suzhou University from January 2015 to April 2016. CT and (or) MRI were used to determine the characteristics of intracranial lesions and the Montreal Cognitive Assessment was used to evaluate the cognitive function of patients. Comparison between groups was made by Mann-Whitney U test. The correlation between ranked data was analyzed by Spearman rank correlation test. Results: Of the 51 patients with an initial diagnosis of brain metastases, 47 (92%) had cognitive impairment, including mild cognitive impairment in 31(61%) and dementia in 16(31%). There was no significant difference in level of cognitive function between the patients with involvement of the left hemisphere alone and those with involvement of the right hemisphere alone (P = 0.425). The patients with involvement of both hemispheres had a significantly lower level of cognitive function than those with involvement of the left hemisphere alone (P = 0.042). The patients with involvement of three or more brain lobes had a significantly lower level of cognitive function than those with involvement of one or two brain lobes (P = 0.015, 0.024). The intracranial lesion volume and edema volume had no significant effect on the overall cognitive function of patients (P = 0.077, 0.178). The patients with > 3 intracranial lesions had a significantly lower level of cognitive function than those with 1-3 intracranial lesions (P = 0.010). Conclusions: More than 90% of patients with an initial diagnosis of brain metastases have cognitive impairment. Cognitive impairment is mainly associated with lesion site, involvement of brain lobes, and number of lesions, but not with lesion volume and edema volume. (authors)