The Fornix May Play a Key Role in Korsakoff's Amnesia Secondary to Subcallosal Artery Infarction.

Background: Subcallosal artery infarction injures the fornix and anterior corpus callosum and sometimes causes Korsakoff's amnesia. We hypothesized that Korsakoff's amnesia might be caused by fornix dysfunction rather than anterior corpus callosum dysfunction in subcallosal artery infarction.
Methods: A systematic review approach was applied to search PubMed and Google Scholar for articles to compare patients who had both bilateral fornix and corpus callosum infarction due to subcallosal artery territory ischemia (vascular event group; V group) with patients who had undergone anterior corpus callosotomy (callosotomy group; C group).
Results: The V group comprised 10 patients (mean age, 63 years; median, 69 years; standard deviation (SD), 14.5 years; 5 males, 5 females). The C group comprised 6 patients (mean age, 23.7 years; median, 20 years; SD, 7.3 years; 3 males, 3 females). Six of 10 patients (60%) with subcallosal artery infarction exhibited Korsakoff's amnesia. One patient showed neither confabulation nor amnesia. Conversely, no amnesia episodes were seen in any patients from the C group ( p = 0.034).
Conclusion: Fornix injury, rather than anterior corpus callosum injury, might be the major cause of Korsakoff's amnesia in patients with subcallosal artery infarction.