Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “AMNESIA”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 811 records · Page 45Linked to original sources
PubMedDate not supplied

Transient global amnesia and cerebral infarct: a case report.

Transient global amnesia refers to a sudden and isolated dysfunction of memory for recent events, lasting a few hours. The pathogenesis of this neurological disorder is still uncertain. The most accepted hypotheses concern ischaemic, epileptic and migraine causes. We now report a case of transient global amnesia associated with computed tomography evidence for a hypodense area in the left thalamus 10 days after the transient memory dysfunctions.

Amnesia↗
PubMed1999

The acute period of recovery from traumatic brain injury: posttraumatic amnesia or posttraumatic confusional state?

OBJECT: The goal of this study was to characterize more fully the cognitive changes that occur during the period of acute recovery after traumatic brain injury (TBI). METHODS: The pattern of performance recovery on attention and memory tests was compared with the results of the Galveston Orientation and Amnesia Test (GOAT). Tests of memory and attention were administered serially to a hospitalized group of patients with TBI of varying severity. The tests differed in their level of complexity and/or requirement for more effortful or strategic processing. The authors found a regular pattern to recovery. As expected, ability to perform on simpler tests was recovered before performance on more effortful ones. The ability to recall three words freely after a 24-hour delay (the operational definition in this study of return to continuous memory) was recovered last, later than normal performance on the GOAT. Ability to perform simple attentional tasks was recovered before the less demanding memory task (recognition); ability to perform more complex attentional tasks was recovered before the free recall of three words after a 24-hour delay. This recovery of attention before memory was most notable and distinct in the group with mild TBI. CONCLUSIONS: The period of recovery after TBI, which is currently termed posttraumatic amnesia, appears to be primarily a confusional state and should be labeled as such. The authors propose a new definition for this acute recovery period and argue that the term posttraumatic confusional state should be used, because it more appropriately and completely characterizes the early period of recovery after TBI.

Adolescent↗
PubMedDate not supplied

Functional MR imaging of psychogenic amnesia: a case report.

We present here a case in which functional MR imaging (fMRI) was done for a patient who developed retrograde psychogenic amnesia for a four year period of her life history after a severe stressful event. We performed the fMRI study for a face recognition task using stimulation with three kinds of face photographs: recognizable familiar faces, unrecognizable friends' faces due to the psychogenic amnesia, and unfamiliar control faces. Different activation patterns between the recognizable faces and unrecognizable faces were found in the limbic area, and especially in the amygdala and hippocampus.

Adult↗
PubMed2006

Implicit memory for novel conceptual associations in amnesia.

In two experiments, we evaluated the status of implicit memory for novel associations in amnesia. Experiment 1 assessed priming in a category exemplar generation task in which contextual information associated with a target could increase the likelihood of target generation. Control participants, but not amnesic patients, showed associative priming. Amnesics' impairment was not due to the use of explicit memory by control subjects but reflected a genuine impairment in implicit memory for novel conceptual associations. Experiment 2 assessed priming in a relatednessjudgment task, in which associative priming was manifest as longer latencies for old than for recombined pairs of unrelated words. Amnesic patients showed intact associative priming in this task. We discuss differences in the status of implicit memory for novel conceptual associations in amnesia, with reference to the nature of the representation that supports priming in the two tasks and the type of processing that is required at test.

Adult↗
PubMed2001

[Regional cerebral blood flow values measured by Xe-CT during the attack of transient global amnesia: a case report].

A 50-year-old right-handed woman was referred to our hospital for further examination of sudden global amnesia. The patient had no history of epilepsy, head injury or cerebral vascular diseases. There were no neurological deficits except for recent memory disturbance. We examined her cerebral blood flow(CBF) immediately during transient global amnesia(TGA) by stable xenon enhanced CT scans(Xe-CT) and twice thereafter. Xe-CT during the attack showed a significant diminution of regional blood flow from the right posterior temporal lobe to the occipital lobe. Conventional MRI scans also had been performed serially but it could not detect the local ischemic event. The ischemic lesion was clearly divided and larger than those cases reported using PET, SPECT, and diffusion-weighted MRI. TGA happens suddenly, and recovery is immediate. It becomes very difficult to study CBF during TGA attack. However stable Xe-CT is capable of examining CBF easily, so we concluded that CBF examination by Xe-CT in TGA patients would be helpful to reveal the mechanism of TGA.

Amnesia, Transient Global↗
PubMed2001

[Qualitative features of confabulation in a case with basal forebrain amnesia].

We investigated qualitative features of confabulation in a case with basal forebrain amnesia. A 66-year-old, right-handed woman with a 8th-grade education, was admitted to the Rehabilitation Department of Tohoku University Hospital, Japan, for evaluation and therapy of amnesia. Her previous medical history included hypertension. Nine months before admission, she went to a hospital because of headache and blurred vision. She was diagnosed as suffering from a suprasellar arachnoid cyst and unruptured aneurysm at the anterior communicating artery. Five months later, resection of the cyst and clipping of the aneurysm was performed. After the operation, she became disoriented and amnesic with marked confabulation. On admission to our hospital 3 months later, she was alert and cooperative. Detailed neuropsychological assessment was performed during the next two months. She remained clinically stable throughout her hospitalization. Neurological examination showed no abnormalities. Brain magnetic resonance images revealed lesions in the bilateral orbito-frontal cortices and basal forebrain. Measurement of blood flow with 123I-IMP single photon emission computed tomography showed hypoperfusion in the bilateral frontotemporal regions. We performed systematic investigations to clarify the qualitative features of her confabulations. Her confabulations included many facts she had experienced before, but they were out of context. Each fact was recalled in isolation or associated with erroneous places, persons or times. Her confabulations were never fantastic or momentary in nature, but were consisted with isolated facts. Experimental investigation revealed that she could recognize individual facts (a person, a place, a task and time) in each episode. However, she could not integrate individual facts into an episode. We propose calling this type of confabulation "mosaic confabulation".

Aged↗
PubMed2002

An unusual presentation of inhalant abuse with dissociative amnesia.

A 38-y-old male with occult inhalant abuse underwent an 18-mo evaluation for presumed seizure disorder. Although past medical history was significant for alcohol abuse, his wife confirmed a 6-y histoy of abstinence. His seizures were characterized as episodes of unconsciousness preceded by a feeling of "things slowing down". No muscular activity was witnessed during these episodes, and upon regaining consciousness the patient had slurred speech, disorientation, dissociative amnesia, and bizarre behavior that resolved spontaneously. Despite 4 emergency department visits, 4 hospital admissions, 5 neurologic and 7 psychiatric outpatient evaluations, extensive work-up was non-diagnostic. These episodes recurred until his wife found him huffing trichloroethylene. Questioning of the patient revealed that huffing always preceded these episodes and that he started huffing after discontinuing alcohol. The patient underwent addiction treatment. Toxic inhalants should be suspected as a substitute drug of abuse in patients attempting abstention. Disorientation clinically similar to dissociative amnesia can occur following loss of consciousness during an episode of trichloroethylene use.

Administration, Inhalation↗
PubMed2003

[A case of amnesia caused by a subcortical hematoma in the left retrosplenial region].

A 54-year-old right-handed woman suffered transient aphasia and persistent amnesia caused by a subcortical hematoma in the left occipital lobe. She appeared to have aphasia, although it disappeared within 3 weeks. It is noteworthy that she had a lesion in the left retrosplenial region but exhibited both verbal and non-verbal memory impairment. However, her intelligence, remote memory and digit span were normal. She had no topographic disturbance. Computed tomography and magnetic resonance imaging revealed a subcortical hematoma in the left occipital lobe including the retrosplenial region. Single photon emission CT showed a low perfusion area in the retrosplenial region and in the left thalamus. We concluded that the retrosplenial amnesia might be caused by the interruption of hippocampal input into the anterior thalamus.

Amnesia↗
PubMed2003

Blockade of NMDA receptors in prelimbic cortex induces an enduring amnesia for odor-reward associative learning.

The competitive antagonist 2-amino-5-phosphonoeptanoic acid (APV) was injected intracerebroventricularly to determine the involvement of NMDA receptors in different stages of memory consolidation. Subsequent experiments used local injections to determine possible sites of drug action. Rats were trained in a rapidly learned olfactory task to find palatable food in a hole in a sponge impregnated with the target odor in the presence of two other sponges with nonrewarded odors. APV injections were made intracerebroventricularly 5 min or 2 hr after the end of the training, and a retention test was given 48 hr later. The results showed that blockade of NMDA receptors immediately after training induces a profound and enduring amnesia with no effect when the treatment is delayed at 2 hr after training. To address the question of the effective sites of action of the intracerebroventricular treatment, APV injections into the hippocampus and into the prelimblic region of the frontal cortex (PLC) were made. Blockade of NMDA receptors into the PLC but not into the hippocampus impaired memory formation of the odor-reward association. The amnesia is not transient, because the retention tests were made 48 hr after training. These results underlie the role of NMDA receptors in the early stage of consolidation of a simple odor-reward associative memory and confirm the role of the PLC in the consolidation of long-term memory.

Amnesia↗
PubMedDate not supplied

[A method for reproducing amnesia in mice by the complex extremal exposure].

It is suggested to reproduce a retrograde amnesia in mice by means of a complex extremal action: emaciating swim in cold water with simultaneous wheel rotation. It was found that nootropes such as pyracetam, mexidol, semax, nooglutil, acephen, and noopept fully or completely prevent from the amnesia development.

Amnesia, Retrograde↗
PubMedDate not supplied

[Transcranial Doppler during transient global amnesia].

INTRODUCTION: Transient global amnesia is a syndrome mainly characterised by an anterograde memory deficit, which disappears in less than 24 hours without leaving any kind of sequelae. Its aetiopathogenesis is still unclear. The ischemic theory became important after hypoperfusion was observed in the mesial region of the temporal lobe using different imaging techniques, although recently the use of diffusion-weighted magnetic resonance imaging by other authors has not revealed these alterations in the cerebral blood flow. CASE REPORT: We report on a transcranial Doppler study carried out in a female patient during the acute phase of the amnesia, with no evidence of hemodynamic alterations or significant asymmetries. Repeating the test after clinical recovery offered values that were similar to those of the previous study. CONCLUSIONS: It is posited that the basis of this process would not be related to ischemia but instead to a mechanism enabling spreading neurogenic depression that is similar to that which takes place during a migraine attack. Treatment with antiplatelet drugs would not, therefore, be recommended but calcium antagonists or beta blockers would be useful in preventing the clinical picture from being repeated.

Aged↗
PubMed2004

[Two cases of transient global amnesia (TGA) immediately after coronary angiography: pathogenesis of the primary TGA].

Two cases of transient global amnesia (TGA) following coronary angiography are reported. Nonionic contrast media was used and injected at room temperature. Both cases showed sudden amnesia about 15 minutes after the left ventriculography. A clinical feature was typical to TGA, showing repeated questions with retrograde and antegrade memory disturbance without any other neurological abnormality. Diffusion-weighted images (DWI) of magnetic resonance imaging revealed no fresh lesion in both cases. The patients recovered from TGA attack within 24 hours. Some cases have been reported which display a manifested TGA following cerebral or coronary angiography. In these situations, embolism, the effect by the contrast media was suspected as the cause of TGA. Since most TGA cases in a classical meaning (primary TGA) showed no abnormality in both DWI and T2-weighted image (T2WI), the cerebral ischemia was not really considered to be the cause of the condition. Therefore, the pathogenesis of the TGA is suggested to be much more functional rather than anatomically abnormal. The pathogenesis of the primary TGA was thought to be some kind of hypersensitivity to the external stress or the stress reaction of the hippocampal cell. This stress may lead to cellular depolarization and the following repolarization (spreading depression), which showed transient abnormality in DWI and not a permanent abnormality in T2WI.

Aged↗
PubMedDate not supplied

[Monitoring of analgesia and amnesia during the general anesthesia in surgeries made on the lungs].

Somatosensorially evoked and auditorially evoked potentials (SSEP and AEP) were evaluated in 75 patients in different stages of general anesthesia during surgical procedures made on the lungs. N19-P23 latent increases of SSEP denoted an adequate level of analgesia. The AEP evaluation is recommended for monitoring the amnesia status during general anesthesia. N1 depression, long-latent N2 and P300 as well as disappearance of AEP and intracerebral asymmetry inversion with predominance of the bioelectric activity in the right cerebral hemisphere are regarded as objective signs of amnesia induction.

Amnesia↗
PubMed1992

Cases from the aerospace residents' teaching file. Case #48. A student pilot is referred for evaluation of a "head injury with post-traumatic amnesia".

A student pilot is referred for evaluation of a "head injury with post-traumatic amnesia." The case study presents a temporal association of injury and symptoms that were assumed to be related. A differential diagnosis of an amnestic syndrome is presented. Transient global amnesia is discussed as a possible etiology until an EEG revealed an epileptiform abnormality. The aeromedical implications, military and FAA, of the clinical and electrophysiologic findings are discussed.

Adult↗
PubMed2004

Pre-electroconvulsive shock administration of calcium channel blockers reduces retrograde amnesia induced by ECS.

Effect of pre-electroconvulsive shock (ECS) administration of calcium channel blockers (CCBs) like verapamil, diltiazem, nifedipine, nimodipine, flunarizine and cinnarizine on retrograde amnesia induced by ECS was examined using passive avoidance paradigm in rats. The groups (Gr 1-7) of adult, male Wistar rats received true ECS with CCBs (5mg/kg; i.p) or vehicle (10 ml/kg; ip) and other groups (Gr 8-14) received sham ECS with CCBs (5mg/kg; i.p) or vehicle (10 ml/kg; i.p). The anti-amnestic activity of CCBs were evaluated using the passive avoidance paradigm in rats. Results showed that, the baseline latencies for all the groups did not differ significantly. Rats receiving true ECS produced significantly lower latencies. There was increase in the post ECS step through latencies of the rats administered CCBs before ECS. Therefore, pre-ECS administration of calcium channel blockers might reduce retrograde amnesia produced by ECS without altering seizure duration.

Amnesia↗
PubMed2006

[Transient global amnesia: indications for a syndrome involving cerebral venous stasis].

In 3 patients, a woman aged 58 and 2 men aged 61 and 58, respectively, who presented to the Emergency Clinic with sudden antegrade and retrograde amnesia, the diagnosis 'transient global amnesia' (TGA) was made. In the first and the last patient the TGA was preceded by a Valsalva-like manoeuvre, i.e. vomiting and tying the shoelaces while bending over and holding his breath, respectively. Until recently, TGA was assumed to have three possible causes: arterial ischaemia (transient ischaemic attack; TIA), migraine and epilepsy. A fourth and more recent hypothesis is cerebral venous stasis. This is in accord with the haemodynamic changes that have been described as a provoking factor in TGA. A Valsalva-like manoeuvre increases the intrathoracic pressure, followed by venous reflux in the internal jugular vein. The resultant cerebral venous congestion can cause temporary ischaemia of mesiotemporal structures, such as the hippocampus, and lead to transient cerebral dysfunction. Recent studies support this haemodynamic pathogenesis. The aetiology of TGA is probably multifactorial, with cerebral venous stasis probably playing an important role. There is still no good explanation for the observation that a causative factor usually leads to a TGA in the same person only once.

Amnesia, Transient Global↗
PubMed1990

Transient global amnesia followed by vertebrobasilar ischemia in a case of dolichoectatic basilar artery.

A 59-year-old hypertensive patient presented with transient global amnesia without neurological signs or symptoms. During the following 3 years, he experienced several attacks of vertebrobasilar insufficiency and a cerebellar infarction. CT scan and MRI found a partially thrombosed dolichoectatic basilar artery but no significant lesion within the limbic system. These data suggest transient global amnesia was due to a transient ischemia in the basilar artery distribution.

Amnesia↗
PubMed1990

Magnetic resonance imaging of the hippocampal formation and mammillary nuclei distinguish medial temporal lobe and diencephalic amnesia.

Studies of circumscribed amnesia have been a useful source of information about the organization of human memory functions. In an effort to obtain neuroanatomical information about the patients being studied, we have used 2 high-resolution protocols for imaging the human brain with magnetic resonance (MR). One provides images of the hippocampus, permitting visualization of the hippocampal formation in considerable detail. The second provides images of the mammillary nuclei. Four amnesic patients with alcoholic Korsakoff's syndrome had abnormally small mammillary nuclei that were barely detectable by MR in most cases. The temporal lobe, hippocampal formation, and parahippocampal gyrus were of normal size. In a second group of 4 (non-Korsakoff) amnesic patients, the opposite findings were obtained. The hippocampal formation was markedly reduced in size in the absence of a detectable change in the size of the temporal lobe. By contrast, the mammillary nuclei, though somewhat reduced in volume, were considerably larger than in the patients with Korsakoff's syndrome. The anatomical findings for individual patients generally corresponded to the severity of their memory impairment. The results show that neuroimaging techniques can distinguish between patients with diencephalic and medial temporal lobe amnesia. These techniques can therefore provide useful information about the crucial issue of patient classification, and they set the stage for exploring possible quantitative and qualitative differences between patients.

Aged↗