A case of amnesia after excision of the septum pellucidum.

Abstract

Tumours of the septum pellucidum (SP) are rare and seldom associated with memory impairment either before or after operation. A patient is described who developed amnesia after transcallosal excision of a tumour of the SP. Radiology did not show any major lesion of the brain areas traditionally associated with amnesia. Because septal nuclei could have been damaged during surgery their possible role in memory functions is discussed.Tumours of the septum pellucidum are rare,' 2 and when they do not lead to compression of other brain structures probably cause no symptoms.Memory disorders before operation have seldom been reported,' 2 are poorly described and then usually in association with more general impairment.2 There is little evidence of improvement of memory disorders after the excision of the tumour.' Even more rare is the finding of memory impairment after the excision of a tumour of the septum pellucidum when there was no memory impairment before the operation.' We describe a patient with a tumour of the septum pellucidum diagnosed by CT scan and MRI, without memory impairment before operation. The patient developed a Korsakoff-type syndrome after surgery that was performed by a transcallosal interfornicial approach.3 We discuss the anatomy of the lesion and the possible role of the septal nuclei in memory function.

Amnestic Syndrome of the Subcallosal Artery: A Novel Infarct Syndrome

“…As a major source of cholinergic input to the hippocampus, the septal nuclei possess extensive afferent and efferent projections to and from the hippocampal formation [10] . However, in case reports of amnesia resulting from septal lesions, the memory defi cits have usually been ascribed to forniceal involvement [11,12] , and in the only case of isolated amnesia attributed to septal nuclear damage, concurrent involvement of the fornix was impossible to defi nitively exclude [13] . Selective septal lesions have also been found to cause hyperreactivity, rage, and hypersexuality [10] .…”

The Orbitofrontal Cortex: Novelty, Deviation from Expectation, and Memory

“…Lesions of the septal region deprive the hippocampus of major cholinergic inputs and give rise to memory deficits similar to those observed after damage to the hippocampal region 55 . Furthermore, damage to this basal forebrain region in patients 56–60 gives rise to a severe amnesic syndrome. Thus, lesions of the frontal cortex that include damage to nearby basal forebrain areas do not provide evidence relevant to the issue of whether a basic memory disorder can follow damage restricted to the orbital and medial frontal cortex.…”

Complication avoidance in transcallosal transforaminal approach to colloid cysts of the anterior third ventriclen: An analysis of 80 cases

“…Transient memory loss is probably due to forniceal manipulation during surgery and is not an unusual postoperative complication. [ 16 24 33 34 35 ] Little and MacCarty reported no incidence of memory loss or personality changes following division of the anterior column of the fornix in patients with colloid cysts. [ 36 ] Memory deficits probably arise from direct and transmitted injury to deep midline and paramedian structures such as the basal forebrain nuclei, thalamic nuclei, septal nuclei, and inferior thalamic peduncle.…”