Acute Amnestic Syndrome Research Articles

Acute amnestic syndrome in fornix lesions: a systematic review of reported cases with a focus on differential diagnosis

IntroductionAcute amnestic syndrome is an uncommon clinical presentation of neurological disease. Differential diagnosis encompasses several syndromes including Wernicke-Korsakoff and transient global amnesia (TGA). Structural lesions of the fornix account for a minority of cases of acute amnestic syndromes. Etiology varies from iatrogenic injury to ischemic, inflammatory, or neoplastic lesions. A prompt diagnosis of the underlying pathology is essential but challenging. The aim of this review is to systematically review the existing literature regarding cases of acute amnestic syndrome associated with non-iatrogenic lesions of the fornix.MethodsWe performed a systematic literature search on PubMed, Scopus, and Web of Science up to September 2023 to identify case reports and case series of patients with amnestic syndrome due to fornix lesions. The systematic review was conducted according to PRISMA guidelines. The research was limited to articles written in English. Cases of fornix damage directly ascribable to a surgical procedure were excluded.ResultsA total of 52 publications reporting 55 cases were included in the review. Focusing on acute/subacute onset, vascular etiology was highly prevalent, being responsible for 78% of cases, 40/55 (74%) of which were due to acute ischemic stroke. The amnestic syndrome was characterized by anterograde amnesia in all patients, associated with retrograde amnesia in 27% of cases. Amnesia was an isolated presentation in most cases. Up to two thirds of patients had persistent memory deficits of any severity at follow-up.DiscussionAcute amnestic syndrome can be rarely caused by fornix lesions. In most cases of acute/subacute presentation, the etiology is ischemic stroke, mainly caused by strokes involving the subcallosal artery territory. The differential diagnosis is challenging and a distinction from common mimics is often difficult on a clinical basis. A high index of suspicion should be maintained to avoid misdiagnosis and provide adequate acute treatment to patients with time-dependent disease, also employing advanced neuroimaging. More research is needed to better understand the outcome and identify prognostic factors in patients with amnestic syndrome due to fornix lesions.

Delayed Leukoencephalopathy after an Opioid-related Acute Amnestic Syndrome (P2-6.003)

Delayed Leukoencephalopathy after an Opioid-related Acute Amnestic Syndrome (P2-6.003)

Bilateral fornix infarction presented with acute amnesia: case report

ABSTRACT Acute episodes of amnestic syndrome can be a challenging diagnostic problem. Except for nonvascular etiology, thalamic strokes or infarction involving several temporal lobe structures has been reported in earlier cases. The authors report a patient who suddenly developed memory loss without any other focal neurologic deficits. Brain magnetic resonance imaging (MRI) with diffusion-weighted imaging (DWI) performed 1 day after onset revealed acute infarction involving the bilateral fornix column and the genu of corpus callosum. Because simple fornix infarcts often have no obvious positive neurological signs, most of the related manifestations were provided by family members, are easy to be diagnosed falsely, and missed in clinical areas, we suggest that bilateral fornix infarction should be considered in the diagnosis of an acute onset amnestic syndrome.

Acute Amnestic Syndrome and Ischemic Stroke: A Case Series.

Stroke is an uncommon cause of amnesia. We describe in detail 3 cases of anterograde amnesia and confabulation secondary to acute ischemic stroke and review the available literature. In our case series, all 3 patients presented with anterograde amnesia and 2 of 3 copresented with prominent confabulation. These symptoms were recognized in delayed fashion, and no patients received IV tissue plasminogen activator (tPA). Although stroke infarct topology was variable, all 3 patients had infarction of the fornix. Long-term follow-up was obtained in 2 of 3 patients: both had persistent memory impairment and were no longer functionally independent. Acute onset anterograde amnesia and confabulation may uncommonly represent acute ischemic stroke. Delays in this diagnosis typically exclude patients from emergent stroke treatment or timely diagnostic stroke evaluation. Clinicians should maintain a high degree of suspicion for ischemic stroke in this setting, especially in patients with comorbid vascular risk factors. Memory impairment secondary to ischemic stroke can produce considerable long-term disability.

Acute amnestic syndrome as a rare consequence of bilateral ischemic hippocampal stroke

Acute amnestic syndrome as a rare consequence of bilateral ischemic hippocampal stroke

Deep cerebral venous thrombosis presenting as acute amnestic syndrome

A 45 year-old man presented with a rapid onset of memory impairment Brain computed tomography showed multiple abnormal low density areas in the deep cerebral white matter. Magnetic resonance imaging revealed bilateral thalamic infarcts and extensive thrombosis of the vein of Galen and the straight sinus, which was confirmed by cerebral angiography. The only potential cause was protein S deficiency. Heparin therapy was started only after the occurrence of a pulmonary embolism. The outcome was excellent Deep cerebral venous thrombosis must be considered as a possible cause of amnestic syndrome. Clinical awareness and early use of anticoagulation may alter the usual fatal outcome.

Korsakoff's syndrome as the initial presentation of multiple sclerosis

A 37-year-old man presented with an acute amnestic syndrome of Korsakoff's type and an upper brain-stem oculomotor syndrome. After a moderate improvement with steroid therapy, he developed progressive behavioural changes due to a frontal lobe syndrome, in addition to motor and visual impairment. Memory performance was investigated on several occasions during an 11-year follow-up. Diagnosis of laboratory-supported definite multiple sclerosis was established and magnetic resonance imaging showed disseminated white matter lesions, especially in both medial temporal lobes. No other cause than multiple sclerosis was found for the amnestic syndrome. Among the rare cases of Korsakoff's syndrome in the course of multiple sclerosis, this is to our knowledge the first case in which a memory deficit was the initial manifestation of the disease.