MR Imaging of Subcallosal Artery Infarct Causing Amnesia after Surgery for Anterior Communicating Artery Aneurysm

Abstract

BACKGROUND AND PURPOSE: During surgery to treat an aneurysm in the anterior communicating artery, injury to the subcallosal artery, a perforator of the anterior communicating artery, may lead to infarction that produces basal forebrain amnesia after surgery. Our purpose was to examine whether 3D MR imaging can detect subcallosal artery infarction in patients with amnesia after surgery for an anterior communicating artery aneurysm.

Postoperative Infarction After Clipping of Unruptured Anterior Communicating Artery Aneurysms: Anatomical Consideration and Type of Infarction Territory

“…Additionally, the HThA supplies the hypothalamus and the lamina terminalis [10]. In our study, the infarction of SCA was usually involved the genu of the corpus callosum, and the symptomatic infarction had involved more at the fornix and the anterior commissure, which is similar to previous studies [17,23,47]. The fornix is known to be the component of the Papez circuit and plays an important role in the memory formation and consolidation [17,42].…”

Postoperative Infarction After Clipping of Unruptured Anterior Communicating Artery Aneurysms: Anatomical Consideration and Type of Infarction Territory

“…Additionally, the HThA supplies the hypothalamus and the lamina terminalis [10]. In our study, the infarction of SCA was usually involved the genu of the corpus callosum, and the symptomatic infarction had involved more at the fornix and the anterior commissure, which is similar to previous studies [17,23,47]. The fornix is known to be the component of the Papez circuit and plays an important role in the memory formation and consolidation [17,42].…”

Relationship between decreased cerebral blood flow and amnesia after microsurgery for anterior communicating artery aneurysm

“…The following mechanism was considered as the cause of decrease of rCBF in the subcallosal, rectal, and anterior cingulate gyri. Both subcallosal and anterior cingulate gyri are known to be perfused by the unpaired subcallosal artery from the ACoA [4,5], and the previous studies reported that infarction caused by the occlusion of the subcallosal artery was related to postoperative amnesia [6,7]. Thus, the current results indicate that decreased rCBF found in both subcallosal and anterior cingulate gyri could be the results of injury or occlusion of that artery in the perioperative period.…”

Revisiting retrosplenial amnesia: Injury of the crus of the fornix following splenial hemorrhage – A 3D magnetic resonance imaging case report

“…Evaluation with isotropic 3D datasets and multiplanar reconstruction, which allows arbitrary reformatting along the long axis of the fornix, is therefore particularly advantageous, especially in the setting of pathological deformation. [ 6 , 11 ] In the present case, 3D T1- and T2-weighted sequences were complementary: T1-weighted imaging facilitated detailed anatomical evaluation, whereas T2-weighted imaging aided lesion detection. Clinically, forniceal injury is often recognized only after an initial confusional state resolves and persistent memory impairment becomes evident, underscoring the importance of reliable forniceal assessment even in the subacute or chronic phase.…”

“…Consistent with this interpretation, high-resolution 3D MRI in the chronic phase demonstrated relative flattening and volume loss of the left mammillary body, a secondary structural change previously reported following forniceal injury. [ 6 , 10 ] Together, these converging functional and structural findings support a circuit-level mechanism underlying the patient’s amnestic syndrome.…”

Postoperative Infarction After Clipping of Unruptured Anterior Communicating Artery Aneurysms: Anatomical Consideration and Type of Infarction Territory

“…Additionally, the HThA supplies the hypothalamus and the lamina terminalis [10]. In our study, the infarction of SCA was usually involved the genu of the corpus callosum, and the symptomatic infarction had involved more at the fornix and the anterior commissure, which is similar to previous studies [17,23,47]. The fornix is known to be the component of the Papez circuit and plays an important role in the memory formation and consolidation [17,42].…”

Relationship between decreased cerebral blood flow and amnesia after microsurgery for anterior communicating artery aneurysm

“…The following mechanism was considered as the cause of decrease of rCBF in the subcallosal, rectal, and anterior cingulate gyri. Both subcallosal and anterior cingulate gyri are known to be perfused by the unpaired subcallosal artery from the ACoA [4,5], and the previous studies reported that infarction caused by the occlusion of the subcallosal artery was related to postoperative amnesia [6,7]. Thus, the current results indicate that decreased rCBF found in both subcallosal and anterior cingulate gyri could be the results of injury or occlusion of that artery in the perioperative period.…”

Revisiting retrosplenial amnesia: Injury of the crus of the fornix following splenial hemorrhage – A 3D magnetic resonance imaging case report

“…Evaluation with isotropic 3D datasets and multiplanar reconstruction, which allows arbitrary reformatting along the long axis of the fornix, is therefore particularly advantageous, especially in the setting of pathological deformation. [ 6 , 11 ] In the present case, 3D T1- and T2-weighted sequences were complementary: T1-weighted imaging facilitated detailed anatomical evaluation, whereas T2-weighted imaging aided lesion detection. Clinically, forniceal injury is often recognized only after an initial confusional state resolves and persistent memory impairment becomes evident, underscoring the importance of reliable forniceal assessment even in the subacute or chronic phase.…”

“…Consistent with this interpretation, high-resolution 3D MRI in the chronic phase demonstrated relative flattening and volume loss of the left mammillary body, a secondary structural change previously reported following forniceal injury. [ 6 , 10 ] Together, these converging functional and structural findings support a circuit-level mechanism underlying the patient’s amnestic syndrome.…”

Postoperative Infarction After Clipping of Unruptured Anterior Communicating Artery Aneurysms: Anatomical Consideration and Type of Infarction Territory

“…Additionally, the HThA supplies the hypothalamus and the lamina terminalis [10]. In our study, the infarction of SCA was usually involved the genu of the corpus callosum, and the symptomatic infarction had involved more at the fornix and the anterior commissure, which is similar to previous studies [17,23,47]. The fornix is known to be the component of the Papez circuit and plays an important role in the memory formation and consolidation [17,42].…”

Relationship between decreased cerebral blood flow and amnesia after microsurgery for anterior communicating artery aneurysm

“…The following mechanism was considered as the cause of decrease of rCBF in the subcallosal, rectal, and anterior cingulate gyri. Both subcallosal and anterior cingulate gyri are known to be perfused by the unpaired subcallosal artery from the ACoA [4,5], and the previous studies reported that infarction caused by the occlusion of the subcallosal artery was related to postoperative amnesia [6,7]. Thus, the current results indicate that decreased rCBF found in both subcallosal and anterior cingulate gyri could be the results of injury or occlusion of that artery in the perioperative period.…”

Revisiting retrosplenial amnesia: Injury of the crus of the fornix following splenial hemorrhage – A 3D magnetic resonance imaging case report

“…Evaluation with isotropic 3D datasets and multiplanar reconstruction, which allows arbitrary reformatting along the long axis of the fornix, is therefore particularly advantageous, especially in the setting of pathological deformation. [ 6 , 11 ] In the present case, 3D T1- and T2-weighted sequences were complementary: T1-weighted imaging facilitated detailed anatomical evaluation, whereas T2-weighted imaging aided lesion detection. Clinically, forniceal injury is often recognized only after an initial confusional state resolves and persistent memory impairment becomes evident, underscoring the importance of reliable forniceal assessment even in the subacute or chronic phase.…”

“…Consistent with this interpretation, high-resolution 3D MRI in the chronic phase demonstrated relative flattening and volume loss of the left mammillary body, a secondary structural change previously reported following forniceal injury. [ 6 , 10 ] Together, these converging functional and structural findings support a circuit-level mechanism underlying the patient’s amnestic syndrome.…”