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 487 records · Page 27Linked to original sources
PubMed2005

Effect of bacosides, alcoholic extract of Bacopa monniera Linn. (brahmi), on experimental amnesia in mice.

To investigate the effect of bacosides (alcoholic extract of brahmi) on scopolamine (3 mg kg(-1), ip), sodium nitrite (75 mg kg(-1), ip) and BN52021 (15 mg kg(-1), ip) induced experimental amnesia in mice, using Morris water maze test, all the agents were administered 30 min before the acquisition trials on each day and repeated for 4 consecutive days, and on 5th day during the retrieval trials. Bacosides on anterograde administration (before training) in mice, significantly decreased the escape latency time (ELT) during the acquisition trials for 4 consecutive days and increased the time spent (TS) in target quadrant during the retrieval trials on 5th day, and on retrograde administration (after training) bacosides were found not to affect TS significantly. Bacosides also significantly decreased the ELT and increased the TS in mice treated anterogradely with scopolamine and sodium nitrite. Bacosides did not exhibit any significant effect on TS of mice treated retrogradely with sodium nitrite. On the other hand, bacosides significantly increased the TS of mice treated retrogradely with BN52021. On the basis of the present results it can be concluded that bacosides facilitate anterograde memory and attenuate anterograde experimental amnesia induced by scopolamine and sodium nitrite possibly by improving acetylcholine level and hypoxic conditions, respectively. Beside this bacosides also reversed BN52021 induced retrograde amnesia, probably due to increase in platelet activating factor (PAF) synthesis by enhancing cerebral glutamate level.

Amnesia↗
PubMedDate not supplied

[Influence of D1 dopamine receptor activation on extinction of passive avoidance and amnesia in aggressive and submissive mice].

In mice with aggressive and submissive behavioral stereotypes, passive avoidance retrieval in extinction and amnesia was shown to be differently dependent on the activation of D1 dopamine receptors. In extinction, agonist of D1 receptors SKF 38393 injected before training or on 12-th day of testing in a dose of 5 mg/kg impaired the retrieval of a conditioned habit in aggressive mice and improved the retrieval in submissive mice. The opposite effects of D1 receptor activation depending on stereotype were also observed in a procedure of amnesia. In aggressive mice, SKF 38393 essentially reduced the resistance to amnesic effects characteristic of this stereotype. In submissive mice, SKF 38393 attenuated the amnesic effect of a detention in a dangerous compartment and restored the amnesic memory trace. Possible mechanisms of selective involvement of D1 receptors in retention of memory trace of aversive stimuli during extinction and amnesia in mice with different stereotypes of behavior are discussed.

2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-ben↗
PubMed2006

[A case of amnesia caused by a falx meningioma in the right frontal region].

A 60-year-old right-handed man suffered frontal lobe dysfunction caused by a falx meningioma. He appeared to have amnesia and left hemiparesis. It is note-worthy that he had a lesion of the right frontal region but exhibited both verbal and non-verbal memory impairment, although his intelligence, remote memory and digit span were normal. Computed tomography and magnetic resonance imaging revealed a falx meningioma in the right frontal lobe including the right cingulate gyrus and corpus callosum. Single photon emission CT revealed a wide area of low perfusion surrounding the right frontal lobe including the cingulate gyrus. After surgery, left hemiparesis and amnesia disappeared. SPECT after surgery showed an area of low perfusion limited to the right frontal region. We concluded that the amnesia in this case might be caused by the interruption of hippocampal input into the cingulate gyrus.

Amnesia↗
PubMed1991

Effects of DM-9384, a cyclic derivative of GABA, on amnesia and decreases in GABAA and muscarinic receptors induced by cycloheximide.

The effects of N-(2,6-dimethyl-phenyl)-2-(2-oxo-1-pyrrolidinyl)-acetamide [DM-9384], a cyclic derivative of GABA, were investigated in the cycloheximide (CXM)-induced amnesia animal model using the passive avoidance task. Pre- and post-training and pre-retention test administration of DM-9384 attenuated the CXM-induced amnesia as indicated by prolongation of step-down latency. Aniracetam, another cyclic derivative of GABA, also showed antiamnesic effects. Scopolamine, a muscarinic ACh receptor antagonist, and the GABA antagonists, picrotoxin and bicuculline, all antagonized the antiamnesic effects of DM-9384. CXM decreased the number of GABAA and muscarinic ACh receptor binding sites. DM-9384 not only inhibited this effect but actually increased the latter. These results suggest that DM-9384 attenuates CXM-induced amnesia by interacting with GA-BAergic and AChergic neuronal systems and enhancing protein synthesis in the brain.

Amnesia↗
PubMed1991

[A case of retrosplenial amnesia].

A case of retrosplenial amnesia was reported. The patient was an 81-year-old right-handed male. He developed amnesic syndrome following cerebral infarction situated left retrosplenial region. His immediate memory was preserved. Recent memory for both verbal and nonverbal modalities was disturbed. He also showed retrograde amnesia for 2 years. The is the first report of retrosplenial amnesia in Japan. We should take into account of the retrosplenial region as a causative site of amnesic syndrome.

Aged↗
PubMedDate not supplied

[Interaction of the serotoninergic and GABA-ergic systems in "psychogenic" amnesia].

The results are analyzed of the influence of blockade of separate components of BD-GABA-iontophoretic complex on activation of memory-trace amnesia under blockade of serotonine PGA synthesis in experiments with conditioned reaction (CR) of passive avoidance in mice. It has been shown that the blockade of serotonine PGA synthesis did not change the behavioral manifestations of amnesia at all terms of testing. The blockade of chlorine channel by picrotoxin and of BD receptors RO15-1788 and RO15-3505 restored the reproduction of the memory trace disturbed against the PGA background; the blockade of GABAA-receptors by bicuculline lost its effectiveness. Activation of serotonin system by sertraline against the PGA background before learning and amnestic influence or before testing of CR of passive avoidance contributed to restoration of CR activating action of bicuculline. It was found that preliminary blockade of PGA serotonine synthesis changed the amnesia development and the character of subsequent restoration of CR of passive avoidance reproduction by blockaders of separate components of BD-GABA-iontophoretic complex.

Amnesia↗
PubMed1990

The Children's Orientation and Amnesia Test: relationship to severity of acute head injury and to recovery of memory.

The Children's Orientation and Amnesia Test (COAT) was developed to assess cognition serially during the early stage of recovery from traumatic brain injury in children and adolescents. The norms for the COAT, which is composed of 16 items evaluating general orientation, temporal orientation, and memory, were defined from data obtained from 146 children aged 3 to 15 years. In 37 patients with head injuries, the duration of posttraumatic amnesia, as indicated by the number of days COAT scores were in the impaired range, was significantly related to both verbal and nonverbal memory at the baseline and 6 and 12 months after injury. COAT scores were a better predictor of verbal and nonverbal memory performance than the Glasgow Coma Scale score at 6 and 12 months after the injury. This study shows that the COAT has adequate reliability and validity as a measure of the duration of posttraumatic amnesia in children and adolescents.

Acute Disease↗
PubMed1990

Psychogenic amnesia.

Psychogenic amnesia is a psychiatric disorder characterized by sudden loss of memory in the absence of organic lesion or disease. The disorder most frequently occurs in association with a severe stressor, such as a natural disaster or military conflict. To facilitate effective treatment and an accurate prognosis, psychogenic amnesia must be differentiated from amnesia of structural or pharmacologic origin. Treatment may involve supportive psychotherapy, behavioral modification or pharmacotherapy. Prognosis for complete recovery is generally good.

Adult↗
PubMed1989

[Left antero-medial thalamic infarction and symptoms of amnesia, aphasia, and dementia].

Three cases of left antero-medial thalamic infarction who showed amnesia, aphasia and dementia were studied comparatively in terms of clinical features and the MRI findings. Case 1 and Case 2, who showed transient amnesia and aphasia respectively, had a single lesion in the left antero-medial thalamus. Case 1 had a lesion in a more ventral part than Case 2, suggesting that Case 1 had a lesion of the bundles into the anterior and dorsomedial thalamic nuclei while Case 2 had a lesion of the ventrolateral thalamic nucleus. On the other hand, Case 3 who showed persistent dementia had multiple lesions in addition to the left antero-medial thalamic infarction. A review of the previous reports and investigations of the present cases suggest that a single ischemic lesion in the left antero-medial thalamus will cause amnesia and/or aphasic symptom while in cases with other multiple lesions it may cause persistent dementia.

Aged↗
PubMed1988

Intensity and duration of amnesia from intravenous midazolam given for sedation.

A clinical study was performed investigating the ability of intravenous midazolam to cause amnesia for visual, auditory and painful stimuli presented during surgical removal of third molars. Various stimuli were presented prior to and after administration of a sufficient quantity of midazolam to produce profound sedation. Recall was then tested immediately after, one day, and one week following the surgery. The study found that midazolam produces at least 20 minutes of profound amnesia for all stimuli in 93 +/- 6% of individuals. However, little correlation was found between the dose of midazolam and the duration of amnesia. Anesthesia literally means the loss of sensation. In the clinical dental situation, the principle sensation lost, when using either regional or general anesthesia, is pain perception. Although prevention of pain sensation is the primary reason patients request local anesthesia prior to invasive dental care, for many patients, control of pain only partially prepares them to receive dental care. These patients request the adjunctive use of sedation or general anesthesia, not for further pain control, but rather requiring periodontal or oral/maxillofacial surgery in which such factors as the sight and taste of blood, the noise of bone-cutting equipment, or the pressure placed on the jaws is not eliminated by local anesthetics. Although effective anxiolytic oral, inhalational, or parenteral agents have been available for several decades, patients still usually retain their memory of events occurring during their dental care, particularly anxiety-provoking events. This memory of the uncomfortable portions of dental care stimulates additional anxiety so that patients may procrastinate when dental care is necessary.(ABSTRACT TRUNCATED AT 250 WORDS)

Amnesia↗
PubMed1987

Implicit expressions of memory in organic amnesia: learning of new facts and associations.

Organic amnesia is a selective impairment of memory that occurs as a consequence of various types of brain damage. Although amnesic patients typically have severe difficulties remembering recent events and acquiring new information, it has been demonstrated that some of their learning abilities are spared. Amnesic patients can retain and express some aspects of a learning experience, despite their inability to recollect the experience in a conscious or explicit manner. This phenomenon is referred to as an implicit expression of memory. The present article considers whether amnesic patients show implicit memory for new facts and associations. Three relevant kinds of evidence are considered: source amnesia, priming effects, and learning of computer vocabulary and commands. It is concluded that (a) amnesic patients do show some implicit memory for new facts and associations, and (b) this type of memory is not entirely spared. Implications for multiple memory system views of amnesia are discussed.

Amnesia↗
PubMed1984

[Episodes of amnesia following whiplash injury to the cervical spine].

A so-called conscious post-traumatic twilight state ("besonnener Dämmerzustand") after a whiplash injury is described here, showing up its similarities with a classic post-traumatic conscious twilight state on the one hand and a classic transient global amnesia on the other hand. The term "conscious twilight state" is analysed and found inappropriate for the state it is meant to describe, and hence the term "post-traumatic transient global amnesia" is proposed instead. A post-traumatic transient global amnesia after whiplash injury is considered to be caused by a concussion.

Adult↗
PubMed1983

[Effect of mental stimulants on electroconvulsive shock-induced retrograde amnesia].

The effect of nootropics on the retrograde amnesia induced by electroshock was studied on a model of the active conditioned escape reaction (pole jumping). In untreated animals the daily application of electroshock for three days, immediately after the training, led to a significant retardation of the development of a conditioned escape reaction. The administration of nootropics influences the development of the retrograde amnesia to different extents, the treatment regimen (application of the drug only during the training and supplementary pretreatment before the first day of training; respectively) being of importance. The antiamnestic effect of Piracetam (100 mg/kg, intraperitoneally) which is good also without pretreatment, may still be potentiated, especially on the fourth day of treatment, by an additional administration of the drug, beginning four days before the first day of treatment. In contrast to this, meclofenoxate hydrochloride (100 mg/kg, intraperitoneally) and pyritinol (100 mg/kg, intraperitoneally) produce a marked inhibition of the development of the retrograde amnesia only after pretreatment. Without pretreatment these drugs exert a slight or no effect. The marked antiamnestic effect of methylglucaminorotate (225 mg/kg, intraperitoneally) and by an additional pretreatment. As to dihydroergotoxin (1 mg/kg; intraperitoneally), both treatment regimens were ineffective in the model used.

Amnesia, Retrograde↗
PubMedDate not supplied

[Transient global amnesia].

Transient global amnesia is a well known syndrome, characterised by sudden loss of short term memory with retrospective amnesia, that appears in otherwise good healthy subjects. Transient global amnesia is often unknown and misunderstood. Authors explain pathogenetic hypothesis and diagnostic criteria, showing some clinical cases.

Amnesia↗
PubMed1984

Amnesia as a major side effect of electroconvulsive shock: the possible involvement of hypothalamic opioid systems.

Electroconvulsive shock (ECS) is used in the treatment of depression and causes antero- and retrograde amnesia as a side effect. One of the many neurochemical effects of ECS is depletion of brain beta-endorphin and Met-enkephalin. These two opioid peptides cause antero- and retrograde amnesia also. Naloxone antagonizes the amnestic effect of ECS and of the opioid peptides. Thus, it is possible that the amnestic effect of ECS is mediated by an endogenous release of the peptides. Surgical posterior hypothalamic deafferentation, but not anterior deafferentation or fornix transection, abolishes the amnestic effect of ECS. This suggests that the hyperactivation of endogenous opioid systems by ECS that leads to amnesia is mediated by posterior ascending fibers to the hypothalamus. The relevance of these considerations to the treatment of depression merits investigation.

Amnesia↗
PubMed1981

Two forms of human amnesia: an analysis of forgetting.

An analysis of forgetting was applied to patients with Korsakoff's syndrome, patients receiving bilateral electroconvulsive therapy (ECT), and case N. A. who has chronic amnesia for verbal material. Patients with Korsakoff's syndrome and case N. A. exhibited a normal forgetting rate, whereas patients receiving ECT exhibited abnormally rapid forgetting. Based on previous findings for the patient H. M., on indirect evidence that the amnesia associated with ECT might be related to temporal lobe dysfunction, and on the diencephalic distribution of lesions in case N. A. and in Korsakoff's syndrome, these results support the hypothesis that these amnesias are distinct syndromes of memory dysfunction. Thus, the stage of memory function disrupted may be different in the two circumstances, and medial temporal and diencephalic brain regions may normally contribute in different ways to the formation of memory.

Adult↗
PubMed1980

Transient global amnesia in childhood.

Transient global amnesia, a brief disorder of recent memory affecting middle-aged and elderly patients, is probably caused by transient ischaemia of the hippocampal regions and other parts of the limbic system related to memory functions. A 13-year-old boy with a single episode of transient global amnesia and a three-year history of recurrent headache is described. It is suggested that some acute confusional states encountered in children with migraine may represent obscured instances of transient global amnesia, and that a brief vasoconstriction of the arteries supplying hippocampal structures is probably responsible for both conditions.

Adolescent↗
PubMed1995

[A case of pineal germinoma presenting with severe amnesia].

Patients who have a pineal germinoma usually present with symptoms of intracranial hypertension or disturbances in vertical ocular motion but rarely present with amnesia. We recently encountered a case of pineal germinoma accompanied by severe amnesia, but not by hydrocephalus. A 32-year-old, right-handed man was admitted with severe memory disturbance which had gradually worsened in the preceding three months. On admission, he was alert and cooperative. His speech was well preserved and not fabricated. He had neither symptoms of intracranial hypertension or visual disturbance. There was no manifestation of interhemispheric disconnection symptoms. His immediate and semantic memory was preserved, however, his recent and antegrade episodic memory was severely impaired. The amnesia involved both verbal and visual modalities. He could recall only 1 out of 5 objects in 5 minutes. He was orientated to people, but not to time and place. And his motivation was severely affected. Magnetic resonance imaging (MRI) showed a heterogeneously enhanced tumor in the splenium and pineal body that extended into the bilateral ventricular trigon through major forceps and was accompanied by edema in the retrosplenial region. The bilateral crura of the fornix was obscured by the tumor. The enlarged pineal body was slightly compressing the upper colliculus but hydrocephalus was not observed. The tumor, which was partially excised through a right parietal corticotomy, had features typical of a germinoma.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗