Retrograde amnesia with transposition in the past: A neuropsychological and PET study of a case.

OBJECTIVE: Retrograde amnesia (RA) with a "transposition in the past" phenomenon has been rarely reported. Patients presenting disproportionate RA for all events over a defined period of time offer an opportunity to investigate the unclear relationship between autobiographical memory and the self, through the well-known self-memory system (SMS). METHOD: We report the case of a 31-year-old right-handed woman who presented to the emergency department of our tertiary care center with an ongoing episode of RA. After resolution of the episode, she had a second transient episode of RA. An extensive neuropsychological battery was performed to assess her autobiographical and nonautobiographical memory during and after the 2 episodes of RA. She also had an 18F-Fluorodeoxyglucose Positron Emission Tomography (FDG PET) scan during the second RA episode. RESULTS: During the 2 RA episodes, results showed lacunar amnesia for autobiographical as well as nonautobiographical memories of the time period between the present and the past 15 years, with preserved anterograde memory. Moreover, her memories before this lost period were more accurate than those after the 2 RA episodes. During the 2 RA episodes, our patient experienced a "transposition in the past" phenomenon. Statistical analysis of the PET scan demonstrated a significant hypometabolism within the right hippocampus. CONCLUSION: The "transposition in the past" phenomenon illustrates the relationship between both episodic and autobiographical memories and the functioning of self, according to the SMS model. Moreover, this case suggests the involvement of the hippocampus in this phenomenon. (PsycINFO Database Record (c) 2020 APA, all rights reserved).

Intraventricular extension of an aneurysmal subarachnoid hemorrhage is an independent predictor of a worse functional outcome.

OBJECTIVE: The objective of this study is to determine the impact of intraventricular hemorrhage (IVH) on the cognitive prognosis of subarachnoid hemorrhage (SAH) due to ruptured cerebral aneurysm, independent of the presence of intraparenchymal hemorrhage, hydrocephalus or vasospasm. PATIENT AND METHODS: A Retrospective review of a prospectively collected database of patients with aneurysmal SAH from July 2009 to November 2016 was performed. Patients were included if they had a saccular aneurysm with a Hunt-Hess grade (HHG) 1-3. Those who underwent craniectomy/clipping and those with vasospasm were excluded. Patients with IVH were grouped into 5 groups depending on the blood distribution in the ventricles. Functional outcomes studied were modified Rankin score (mRS) 0-2, cognitive impairment and memory impairment, and the presence of amnesia to the event. A univariate followed by a multivariate analysis ware performed. RESULTS: A total of 443 patients were identified and 124 patients met the criterion. There were no significant differences in the proportion of patients with mRS of 0-2 between patients with IVH and those without IVH but with EVD (external ventricular drain). There was a higher proportion of cognitive deficits in patients with IVH (71.95%), compared to those without (31.58%; p = 0.01). Patients with IVH had a higher rate of anterograde amnesia (100% vs. 4.3% p < 0.0001), lower rate of mRS 0-2 (78% vs 100% p < 0.001), and higher rate of cognitive impairment (71.9% vs. 13% p < 0.0001) compared with those who did not require an EVD. Grade 3 and grade 4 were shown to have lower rate of patients with mRS 0-2 and a higher rate of cognitive impairment. In multivariate analysis, independent predictors of cognitive and memory impairment were increasing HHG (OR = 155.33; P < 0.01), ACOM/A1/ACA/anterior choroidal aneurysms, (OR = 5.24; P = 0.04), increasing Fischer scale (OR = 6.93; P = 0.01), and increasing IVH grade (OR = 6.9; P = 0.01). Only worse HHG (OR = 2704.22; P = 0.01) and IVH grade 2-4 were associated (perfect predictor, OR cannot be extracted) with anterograde amnesia. CONCLUSION: IVH is an independent prognosticator of SAH cognitive outcomes. The effect of IVH drainage and other intraventricular therapies on SAH course is an attractive topic for further investigation.

Episodic future thinking and future-based decision-making in a case of retrograde amnesia.

We investigated episodic future thinking (EFT) and future-based cognition and decision-making in patient SG, who developed a dense retrograde amnesia following hypoxia due to a cardiac arrest. Despite intact general cognitive and executive functioning, SG was unable to remember events from his entire lifetime. He had, however, relatively spared anterograde memory and general semantic knowledge. Voxel-based morphometry detected a reduction of gray matter in the thalamus, cerebellum and fusiform gyrus bilaterally, and, at a reduced threshold, in several regions of the autobiographical memory network, including the hippocampi. We show that SG is unable to imagine personal future events, but can imagine fictitious events not self-relevant and not located in subjective time. Despite severely impaired EFT, SG shows normal attitudes towards the future time, and normal delay discounting rates. These findings suggest that retrieval of autobiographical information from long-term memory is necessary for EFT. However, relatively spared anterograde memory and general semantic knowledge may be sufficient to allow construction of fictitious experiences. As well, EFT is not necessary to drive future-oriented cognition and choice. These findings highlight the relation between autobiographical memory and EFT, and the fractionation of human temporal consciousness. Moreover, they contribute to our understanding of retrograde amnesia as an impairment of memory as well as future thinking.

Reversible hippocampal lesions detected on magnetic resonance imaging in two cases of transient selective amnesia for simple machine operation.

We report two extremely rare cases involving the development of transient selective retrograde amnesia for simple machine operation lasting for several hours. A 61-year-old male taxi driver suddenly became unable to operate a taximeter, and a 66-year-old female janitor suddenly became unable to use a fax machine. They could precisely recount their episodes to others both during and after the attacks, and their memories during their attacks corresponded to the memory of the witness and the medical records of the doctor, respectively. Therefore, it appears that these individuals remained alert and did not develop anterograde amnesia during their attacks. On day 4, they underwent high-resolution magnetic resonance imaging (MRI), and diffusion-weighted MRI with 2-mm section thickness revealed small high-intensity signal lesions in the left hippocampal cornu ammonis area 1 (CA1) region. However, these lesions disappeared during the chronic phase. This is the first report describing lesions detected by MRI in patients with transient selective amnesia without anterograde amnesia. Reversible damage to the hippocampal CA1 region may cause transient selective amnesia by impairing the retrieval of relevant memories.

Clinical characteristics and brain PET findings in 3 cases of dissociative amnesia: disproportionate retrograde deficit and posterior middle temporal gyrus hypometabolism.

BACKGROUND: Precipitated by psychological stress, dissociative amnesia occurs in the absence of identifiable brain damage. Its clinical characteristics and functional neural basis are still a matter of controversy. METHODS: In the present paper, we report 3 cases of retrograde autobiographical amnesia, characterized by an acute onset concomitant with emotional/neurological precipitants. We present 2 cases of dissociative amnesia with fugue (cases 1 and 2), and one case of focal dissociative amnesia after a minor head trauma (case 3). The individual case histories and neuropsychological characteristics are reported, as well as the whole-brain voxel-based 18FDG-PET metabolic findings obtained at group-level in comparison to 15 healthy subjects. RESULTS: All patients suffered from autobiographical memory loss, in the absence of structural lesion. They had no significant impairment of anterograde memory or of executive function. Impairment of autobiographical memory was complete for two of the three patients, with loss of personal identity (cases 1 and 2). A clinical recovery was found for the two patients in whom follow-up was available (cases 2 and 3). Voxel-based group analysis highlighted a metabolic impairment of the right posterior middle temporal gyrus. 18FDG-PET was repeated in case 3, and showed a complete functional brain recovery. CONCLUSION: The situation of dissociative amnesia with disproportionate retrograde amnesia is clinically heterogeneous between individuals. Our findings may suggest that impairment of high-level integration of visual and/or emotional information processing involving dysfunction of the right posterior middle temporal gyrus could reduce triggering of multi-modal visual memory traces, thus impeding reactivation of aversive memories.

Psychogenic amnesia and self-identity: a multimodal functional investigation.

BACKGROUND: Patients with psychogenic amnesia generally suffer from episodic memory deficits associated with an impairment of self-identity. While the first is generally attributed to limbic dysfunction, the latter might be related to posterior parietal cortex. METHODS AND RESULTS: In a patient with acute repetitive psychogenic amnesia, three different functional investigations (fMRI, electrical-neuroimaging, PET) during both resting-state and a behavioural paradigm testing 'time-travel' showed left posterior parietal activation, unlike in 12 control subjects. CONCLUSION: Impairment of self-identity and episodic memory in psychogenic amnesia may be associated with functional alterations of left posterior parietal cortex.

When the past is lost: focal retrograde amnesia. Focus on the "functional" form.

We report the clinical findings and neuropsychological profiles of a sample of patients exhibiting a focal retrograde amnesia (FRA) seen consecutively during the period 1992-2007. The cohort comprised 13 patients, five males, with a mean age of 30 years (range 16-49). They were given a neurologic examination, psychiatric interview and formal neuropsychological examination (all but one) during the amnesic phase, underwent neuroimaging, and were followed up for six months to ten years. All presented with an acute amnesia characterized by an impaired recollection of memories predating the acute event, with spared or minimally and transiently affected anterograde memory, thus consistent with FRA. The events triggering FRA varied widely: mild to severe head injury, road accident without head injury, seizure, dissociative fugue, BDZ overdose, posttraumatic headache, syncope, migraine attack, acute distress. The neuropsychological hallmark of FRA was a selective or prominent impairment of autobiographical memory. The defect was often so severe as to cover most or all of the patients' lives and, in some cases, to erase the knowledge of their own identity. Conventional neuroimaging (brain CT and MRI) was unimpressive. Cerebral SPECT/PET disclosed unilateral frontal hypoperfusion in three (two left). All but one patient fully recovered, time of recovery ranging from three days to six months. FRA is a condition reflecting a block of memory function triggered by heterogeneous events, including both physical and psychic insults. Analogies shared with the more frequently encountered and better known condition of transient global amnesia suggests common pathogenetic mechanisms. A tentative nosographic classification of FRA is finally offered.

Item recognition is less impaired than recall and associative recognition in a patient with selective hippocampal damage.

This article explores the recall, item recognition, and associative recognition memory of patient B.E., whose pattern of retrograde amnesia was reported by Kapur and Brooks (1999; Hippocampus 9:1-8). Structural magnetic resonance imaging (MRI) has shown that B.E. has bilateral damage restricted to the hippocampus. The structural damage he had sustained was accompanied by bilateral hypoperfusion of the temporal lobe, revealed by positron emission tomography (PET), and which single photon emission computed tomography (SPECT) suggested was greater in the left than the right temporal lobe. B.E. showed a global anterograde amnesia for verbal material, but he displayed some sparing of nonverbal item recognition relative to nonverbal recall and associative recognition. His performance on an item recognition task that used the remember/know procedure and another that involved repetition of the test phase, to reduce the difference between the familiarity of the targets and foils, suggested that his relatively spared nonverbal item recognition may have been mainly supported by familiarity. This finding is consistent with the view that the anterior temporal lobe, including the perirhinal cortex, can support familiarity-based memory judgments (Brown and Bashir, 2002; Philos Trans R Soc Lond B 357:1083-1095). B.E.'s data also highlight the importance of functional as well as structural scan information for interpreting the pattern of memory deficits shown by patients with selective hippocampal structural lesions.

A SPECT study of the anatomy of transient global amnesia.

This report describes single photon emission tomography (SPECT) evidence of transient, relative hypoperfusion of the right basal ganglia and left temporal lobe in a 60-year-old man studied during the acute phase of classical transient global amnesia (TGA). The findings are interpreted in the light of previous reports indicating that involvement of the right hemisphere or both cerebral hemispheres consistently predicts severe retrograde amnesia, in addition to the typical loss of anterograde memory observed during TGA. These deficits involving the right hemisphere and left temporal lobe may reflect disruption of circuits mediating episodic memory retrieval and memory encoding, respectively.

Retrograde amnesia for world knowledge and preserved memory for autobiographic events. A case report.

A patient (PC) with severe and chronic retrograde amnesia for world knowledge (tested with famous events and famous faces), but unimpaired autobiographical memory is described. The 64-year-old man had traumatic brain injury four years prior to the present evaluation. Current brain imaging showed principally damage involving the infero-lateral prefrontal and the lateral temporal regions of the left-hemisphere. PC was of average intelligence, had no depression and only minor language problems, but manifested some additional anterograde memory deficits and performed subaverage in various frontal lobe-sensitive tests. Patient PC represents one of the very few cases with a preserved retrograde episodic and an impaired retrograde knowledge system, showing a dissociation between preserved retrieval of autobiographical events and amnesia for nonpersonal famous events. It is hypothesized that the sparing of autobiographical memories can be linked to the integrity of the right frontal and temporo-polar cortices.

Transient retrograde amnesia associated with impaired naming of living categories.

A ease of pure retrograde amnesia following mild head injury is reported. The patient, who also showed a deficit in verbal fluency and a living/non-living dissociation in naming during the amnesic period, recovered progressively in about ten days post-trauma. Both a psychogenic and an organic origin could be taken into account. A mechanism (no matter if psychogenic or organic) can be hypothesized, which produces a functional inhibition also involving performances that are unlikely to be affected by psychological factors.

Right temporofrontal cortex as critical locus for the ecphory of old episodic memories.

A 54 year old patient of average intelligence with a severe and enduring loss of old autobiographical memories after herpes simplex type 1 infection is described. She was tested with a comprehensive neuropsychological battery two years after the infection. Special emphasis was laid on examining different aspects of retrograde memory. The neurological examination involved MRI and SPECT. Brain damage was found mainly in the right temporofrontal region, but minor left sided damage to this region seems possible. The patient was in the normal or slightly subnormal range for all tested anterograde memory functions, but manifested severe retrograde memory deficits with respect to episodic old memories and more moderate deficits in tests of general knowledge (semantic old memories). It is concluded that the ecphory of old autobiographical memories relies heavily on an activation of the right lateral temporofrontal junction area, but that probably only some complementary left hemispheric damage to these regions will lead to major and persistent retrograde amnesia. Alternatively, the disconnection between major prefrontal and posterior cortical regions may provide a basis for retrograde amnesia.

P300 abnormalities in patients with selective impairment of recent memory.

We recorded auditory event-related potential (ERP) by using the standard oddball paradigm in seven amnestic patients. Patients were divided into three groups according to brain CT or MRI findings. (1) Three patients with no detectable lesion, including two patients studied during the episode of transient global amnesia, showed a well-defined P300. (2) Three patients with detectable lesions in the mesial temporal lobes did not show any wave form corresponding to P300. In two of these three patients, the ERP wave form showed a significant change in accordance with the improvement of MRI findings. (3) One patient who had a hypothalamic lesion due to total resection of craniopharyngioma showed a low-amplitude P300. Although neuropsychological examinations showed selective and severe impairment of recent memory function in all of these patients, no significant relationship was found between the degree of memory disturbance and P300 abnormality. These results suggest that P300 is more affected by existence and extension of brain lesions, especially in the mesial temporal lobes, rather than degree of memory disturbance. However, these results do not necessarily suggest that the potential generated in the mesial temporal lobes is directly recorded as a component of the scalp-recorded P300.

Transient global amnesia and cortical blindness after vertebral angiography: further evidence for the role of arterial spasm.

We describe a series of six patients who experienced severe retrograde amnesia (five cases) or cortical blindness (one case) during selective vertebral angiography. All angiograms were obtained with the same nonionic contrast medium. Analysis of the contrast batch demonstrated no abnormalities, but investigation of the angiographic suite revealed a faulty contrast warming cabinet resulting in injection of contrast material above body temperature. The warming cabinet was withdrawn, and the complication has not recurred. We believe that these symptoms reflect ischemia caused by vertebral arterial spasm.

Neuropsychological and neuroanatomical correlates of confabulation.

In the present exploratory investigation we report nine confabulatory patients of comparable age, education, and general level of intelligence in the acute epoch of recovery after rupture and clipping of ACoA aneurysms. Five of the nine cases had "spontaneous" confabulation, severe anterograde amnesia, markedly poor attentional and executive functions, and denial of illness. These patients all had multiple lesions that involved basal forebrain, ventral frontal lobe, and striatum. The other four patients manifested only "momentary" or "provoked" confabulations. These patients also had severe anterograde amnesia but showed relatively mild deficits in executive functions. These patients had lesions restricted to the basal forebrain except for one who had additional orbital frontal damage. Analysis of these two groups of confabulatory patients suggests that there is a common profile of deficits and anatomic foundation associated with confabulation; "spontaneous" confabulation appears to require extensive, simultaneous disruption of medial basal forebrain and frontal cognitive systems resulting in profound executive and memory deficits, whereas more limited lesions to the basal forebrain or orbital frontal cortex will result in "transient" or "provoked" confabulatory responses and a more restricted profile of cognitive deficits.

Isolated prolonged retrograde amnesia.

We describe a patient who had isolated retrograde amnesia of 1-year duration without anterograde amnesia after recovery from encephalitis. Single photon emission computed tomography using 123I-IMP revealed that left temporal lobe abnormality. We postulate that the learning ability for new information and recalling ability for old information involve different neural structures, and there is a possible relationship between isolated retrograde amnesia and left temporal dysfunction.