Transient Global Amnesia and Brain Tumour: Chance Concurrence or Aetiological Association Case Report and Systematic Literature Review

Abstract

We report a patient presenting with episodes of transient amnesia, some with features suggestive of transient global amnesia (TGA), and some more reminiscent of transient epileptic amnesia. Investigation with neuroimaging revealed an intrinsic lesion in the right amygdala, with features suggestive of low-grade neoplasia. We undertook a systematic review of the literature on TGA and brain tumour. Fewer than 20 cases were identified, some of which did not conform to the clinical diagnostic criteria for TGA. Hence, the concurrence of brain tumour and TGA is very rare and of doubtful aetiological relevance. In some brain tumour-associated cases, epilepsy may be masquerading as TGA.

Transient Global Amnesia as the First Clinical Symptom for Malignant B-Cell Lymphoma with Central Nervous System Involvement

“…Our case, along with similar other publications, reemphasizes the role of the hippocampus and amygdala in amnestic presentations and the need to further investigate via imaging if there is a question about diagnosis of TGA in the ER [ 5 , 6 ]. Less than two dozen cases have been reported where TGA was later identified as neoplastic or other similar pathological processes, mostly meningioma [ 5 , 7 ]. Therefore, it may not be wrong to consider further imaging (i.e., MRI with thin DWI cuts) if the patient's presentation casts the slightest doubt on the diagnosis of TGA [ 8 ].…”

“…Various phenomena to explain TGA have been described, with migraines and vascular, hypoxemic, and metabolic hypotheses being pointed out in various animal and imaging models, with general consensus on the amygdala and hippocampus as being the sites of involvement [ 1 , 4 , 5 ]. Our case, along with similar other publications, reemphasizes the role of the hippocampus and amygdala in amnestic presentations and the need to further investigate via imaging if there is a question about diagnosis of TGA in the ER [ 5 , 6 ]. Less than two dozen cases have been reported where TGA was later identified as neoplastic or other similar pathological processes, mostly meningioma [ 5 , 7 ].…”

“…After retrospectively analyzing this reported case, we propose special protocolled thin hippocampal cuts for patients diagnosed with TGA [ 5 , 9 ]. We understand that, for most patients in ER with a textbook presentation of TGA, further testing and imaging may not be feasible mainly due to the costs involved.…”

Transient Global Amnesia in a Patient with Pituitary Adenoma: Causal or Chance Association?

“…Among the cases, some tumors seem to have no causal association with the TGA episode because of their locations being distant from memory-eloquent structures (e.g., nondominant hemispheric tumor) [2, 4]. In such cases, brain tumors may be purely coincidental [2, 4, 5]. In contrast, in other cases, including ours, the tumors were close to or located in the memory-eloquent area [3, 6, 8, 9].…”

“…TGA cases associated with brain tumors have been rare in the literature [2, 3, 4, 5, 6, 7, 8, 9]. Among those, there have been only 2 cases associated with a pituitary tumor, to the best of our knowledge [3, 4], which had the characteristics of transient epileptic amnesia [10].…”