UMLS:C0233794 - FACTA Search

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Query: UMLS:C0233794 (memory impairment)
7,237 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Amyotrophic lateral sclerosis (ALS), Parkinson's disease (PD), and Alzheimer's disease (AD) are human neurological disorders which occur in middle and late life. These three diseases share certain features: they are slowly progressive; transmitter-specific groups of neurons are selectively affected by disease processes; and affected nerve cells exhibit cytoskeletal pathology. The causes and mechanisms of cell injury are unknown, and there are no treatments which directly affect the disease process. Dysfunction and death of these specific cell groups account for different clinical syndromes. In ALS, patients become paralyzed, at-risk cholinergic motor neurons in the spinal cord develop neurofilamentous swellings of proximal axons, and distal axons atrophy. In PD, affected individuals show slowed movements, tremor, and rigidity. These clinical findings are attributed to regeneration of dopaminergic neurons of the substantia nigra, a cell group showing abnormal accumulations of neurofilament antigens in the form of Lewy bodies. In AD, patients develop dementia (a syndrome of cognitive and memory impairment), and cholinergic neurons of the basal forebrain and certain other populations of nerve cells develop abnormalities of the cytoskeleton. These include perikaryal neurofibrillary tangles and enlarged distal axons which appear as neurites in senile plaques. Certain features of ALS, PD, and AD are recapitulated in three animal models described in this review. Hereditary Canine Spinal Muscular Atrophy (HCSMA), a dominantly inherited motor neuron disease, shows many clinical and pathological features in common with ALS. Affected dogs are clinically weak, have denervation atrophy of muscles, and develop neurofilamentous swellings of proximal axons, atrophy of distal axons, and degeneration of motor neurons. These abnormalities of axonal caliber are associated with impaired transport of the neurofilament triplet proteins and a maldistribution of phosphorylated neurofilaments. Intoxication of macaques with 1-methyl-4-]henyl-1,2,3,6,tetrahydropyridine (MPTP) produces a Parkinsonian syndrome due to selective injury of dopaminergic neurons in the substantia nigra and associated denervation of the striatum. Finally, aged rhesus monkeys (older than 23 years of age) show cognitive and memory deficits and exhibit senile plaques whose neurites are derived from cholinergic and other transmitter systems. Although these macaques do not have AD, they do provide a model for examining the relationships between age-associated cognitive deficits and pathological changes occurring in certain transmitter systems of primates.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Animal models of degenerative neurological disease. 360 87

We investigated the profile of cognitive and memory deficits of 22 Parkinson's disease (PD), 24 amyotrophic lateral sclerosis (ALS) patients and 26 age-matched controls. The patients were at the early phase of the disease and untreated. The ALS patients exhibited deficits in simple visuoperceptual functions and in complex visuoperceptual reasoning (Digit Symbol and Block Design tests), whereas the PD patients showed deficits only in simple visuoperceptual functions. Moreover, both ALS and PD patients had impairment in tasks requiring set shifting from one reaction to another that may suggest frontal lobe dysfunction. The ALS and PD patients also showed impairment in the task of learning a word list with effort-demanding organization of the material to be remembered. However, preserved delayed recall of logical passages suggests that memory, per se, is not impaired in ALS or in PD. The patterns of errors in a test of recognition of learned words imply, at least partially, different underlying deficits in the two diseases. An inability to inhibit irrelevant information may contribute to memory impairment in ALS patients, whereas the memory deficit in PD may derive from lowered motivation or initiating behaviour.
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PMID:Cognitive and memory deficits in untreated Parkinson's disease and amyotrophic lateral sclerosis patients: a comparative study. 811 9

Hirano bodies are refractile eosinophilic rod-like structures, initially observed in Guamanian (Chamorro) patients with amyotrophic lateral sclerosis and parkinsonism-dementia complex. Subsequent investigations revealed that Hirano bodies have a distinct topographic distribution in the hippocampus, and that their number increases in the pyramidal layer of Sommer's sector but not in the stratum lacunosum with advancing age. Since patients with Alzheimer's disease (AD) have significantly more Hirano bodies than normal subjects in the same age range, the inclusions appear seem to be of relevance in this disease. Immunohistochemical and electron microscopic studies have demonstrated that the main components of Hirano bodies are abnormal micro-filaments, and that not only molecules associated with cell cytoskeleton, but also some stress-related proteins and growth factors such as beta-amyloid precursor protein, hippocampal cholinergic neurostimulating peptide (HCNP), transforming growth factor beta 3 are present in Hirano bodies. The accumulation of HCNP in Hirano bodies suggests that patients bearing these inclusions may have a disturbance of the septohippocampal cholinergic system, considered to be of importance for le arning and memory formation, and hence be related to the memory impairment of AD.
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PMID:Hirano bodies and Alzheimer's disease. 913 Aug 18

Three cases are reported with dementia and ubiquitin-positive but tau-negative inclusion bodies. All patients had a semantic dementia and the clinical details of two of these have been published as the first description of a selective semantic memory impairment. The original diagnosis had been of Pick's disease based on frontotemporal atrophy, but re-examination has revealed ubiquitin-positive but tau-negative inclusions as well as neurites in the frontotemporal cortices and ubiquitin-positive, intracytoplasmic inclusions in the granule cells of the dentate fascia. These inclusions are identical to those reported in association with amyotrophic lateral sclerosis (motor neuron disease), but none were seen in brainstem or spinal cord motor neurons.
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PMID:Semantic dementia with ubiquitin-positive tau-negative inclusion bodies. 1064 35

Neuropsychological investigations of amyotrophic lateral sclerosis (ALS) patients have revealed variable results on specific tests, despite a similar overall cognitive profile of predominantly executive dysfunction with some evidence of memory impairment. The most striking and consistent deficit is found using tests of verbal fluency. The current investigation explored why verbal fluency is particularly sensitive to the impairment in ALS, by investigating some of the underlying cognitive processes: (i) intrinsic response generation; (ii) phonological loop functions; and (iii) simple word retrieval. Twenty-two ALS patients and 25 healthy controls were investigated. The battery included: (i) written and spoken letter-based fluency, category fluency, design fluency; (ii) the Phonological Similarities effect and Word Length Effect; and (iii) computerised sentence completion and confrontational naming. The tests were designed to control for motor speed and to accommodate for the range of disabilities that are present in ALS patients. Significant impairments were found on some tests of intrinsic response generation, namely the Written Verbal Fluency Test, Category Fluency Test (generation of animal names) and Design Fluency Test. Phonological loop functions appeared to be intact with evidence of both the Phonological Similarities and Word Length Effects, but the ALS patients displayed significantly reduced working memory capacity. No deficits were found on tests of simple word retrieval. The findings indicate that verbal fluency impairments in ALS patients result from a higher order dysfunction, implicating deficits in the supervisory attentional system or central executive component of working memory, and are not caused or exaggerated by an impairment in phonological loop functions or in primary linguistic abilities. The study also demonstrates the importance of controlling for differences in motor speed, which may have served to exaggerate the presence of cognitive deficits in ALS patients reported by some other studies.
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PMID:Verbal fluency and executive dysfunction in amyotrophic lateral sclerosis (ALS). 1068 49

The presence of subclinical cognitive impairment in patients with amyotrophic lateral sclerosis (ALS) is investigated using neuropsychological assessment and event-related potential recordings (ERP). An extensive battery of neuropsychological tests assessing the domains of attention, memory, language, visuo-spatial and executive functions were administered to 20 non-demented patients with sporadic ALS and 13 age- and education-matched healthy control subjects. Mismatch negativity (MMN), P3b, P3a (novelty P300) and contingent negative variation (CNV) were recorded. ALS patients were significantly impaired in tests of working memory, sustained attention, response inhibition, naming, verbal fluency and complex visuo-spatial processing. The memory impairment seemed to be secondary to deficits in forming learning strategies and retrieval. In ERP recordings, P3a and P3b amplitudes of ALS patients were lower compared with the controls, P3a latencies were significantly longer and mean CNV amplitudes were higher. These results indicate subclinical impairment of cognitive functions in patients with ALS. The pattern of cognitive impairment suggests the dysfunction of the frontal network.
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PMID:Cognitive impairment in amyotrophic lateral sclerosis: evidence from neuropsychological investigation and event-related potentials. 1206 96

We describe a patient with amyotrophic lateral sclerosis with dementia (ALS-D) displaying a long clinical course. A 68-year-old Japanese male with no family history of note was admitted complaining of severe dysarthria and dysphagia. At 63 years old, Pick's disease was diagnosed on the basis of abnormal behavior, such as "Denkfaulheit" and moria, and temporal lobe atrophy observed on magnetic resonance imaging (MRI). Five years after onset, dysarthria and dysphagia emerged, and gradually worsened. On admission, muscular weakness of the upper extremities, fasciculation, and exaggerated tendon stretch reflexes were noted. Needle electromyography performed on the left upper and lower extremities revealed neurogenic pattern changes. Based on these findings and clinical course, ALS-D was diagnosed. Due to severe bulbar palsy, verbal communication was impossible. However, neither specific symptoms of dementia nor abnormal behavior was demonstrated, although this latter had been observed 5 years ago, with only short-term memory impairment apparent. MRI disclosed severe knife-edge atrophy of bilateral temporal lobes, most prominently in the anterior regions. SPECT images revealed decreased uptake of tracer in bilateral inferior temporal lobes, predominantly on the left side. The patient died suddenly 4 months after admission, and post-mortem examination was not conducted. Total clinical course was about 8 years. Several cases of ALS-D have displayed similar clinical courses to the presented case. Some of these would also have initially been diagnosed as Pick's disease. We speculate that cases displaying psychiatric symptoms for several years and initially diagnosed as Pick's disease may finally be diagnosed as ALS-D upon the eventual emergence of motor symptoms(bulbar palsy).
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PMID:[A case of amyotrophic lateral sclerosis with dementia presenting long clinical course]. 1268 97

Subtle neuropsychological deficits have been described in patients affected by amyotrophic lateral sclerosis (ALS) without dementia. Overall, selective impairment in memory function has been reported, but the source of memory impairment in ALS has yet to be defined. We performed neuropsychological screening in 20 ALS patients. Semantic encoding and post-encoding cue effects on the retrieval of word lists were investigated in the ALS patients and normal controls. Severity of memory impairment was correlated to cerebral blood perfusion detected by single photon emission computed tomography (SPECT). ALS patients showed moderate impairments in frontal and memory tests. Short-term memory was normal, while serial position retrieval of word lists with normal recency effect but poor primacy effect showed long-term memory deficit. ALS patients performed better in cued encoding than in cued post-encoding recall condition. In the cued post-encoding condition, the primacy effect in word list recall improved significantly in controls, but not in ALS patients, as compared with both the free recall and cued encoding conditions. SPECT hypoperfusion was observed in frontal and temporal areas in ALS patients. ALS patients showed a long-term memory deficit which did not improve in cued post-encoding condition as it does for controls. We hypothesize abnormal retrieval processes related to frontal lobe dysfunction which entails difficulties in generating stable long-memory traces at encoding.
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PMID:Memory deficits and retrieval processes in ALS. 1275 94

Aluminum (Al), a known neurotoxin, has been implicated in Alzheimer's Disease (AD), Amyotrophic Lateral Sclerosis (ALS), Parkinsonism Dementia Complex, etc., and it causes extensive damage to the nervous system, including the impairment of learning and memory. However, to date, the mechanism of Al neurotoxicity has not been fully elucidated. Neuronal apoptosis has become a focus of interest, as it has been reported to play a key role in the impairment of learning and memory processes (Thompson, Science 267:1456, 1995). The Bcl-2 gene acts as an important effector for inhibiting apoptosis. In the present study we observe neuronal apoptosis in association with learning and memory impairment, as well as regional brain alterations in Bcl-2 expression in rats chronically exposed to Al. The chronic Al-intoxicated model was established by i.p. injection of AlCl3 in adult Sprague Dawley rats for 3 successive days, with one-day intervals, for 60 days. After exposure, the step-down test was performed to examine the behavioral reaction of the rats. Neuronal apoptosis and Bcl-2 protein expression in different regions of rat brain were then assessed by an immunohistochemical method. In the step-down test, the latency of Al-exposed rats was significantly lower than that of controls. Also, the number of performance errors in 5 minutes of exposure was significantly higher than that of controls. Neuronal apoptosis was extensive in the brain of Al-exposed groups, and the expressions of Bcl-2 protein in frontal cortex, cerebellum and hippocampus of Al-exposed rats was stronger. In conclusion, chronic Al-exposure in rats is associated with neuronal apoptosis in brain, and impaired learning and memory. Augmented Bcl-2 protein expression may be a stimulated compensatory mechanism.
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PMID:The relationship between Bcl-gene expression and learning and memory impairment in chronic aluminum-exposed rats. 1796 40

AIT-082 (an analog of hypoxanthine) is an orally-active nerve growth factor (NGF) agonist under development by NeoTherapeutics as a potential treatment for Alzheimer's disease (AD), stroke and motor neuron disease. A phase II safety and efficacy trial in AD, originally scheduled to begin in the summer of 1997 [283677], began in May 1998 [286975,285562]. The study will enroll more than 60 AD patients [286975]. In February 1998, NeoTherapeutics began a phase I multiple-dose pharmacokinetic study of AIT-082 in 24 healthy elderly volunteers. Subjects of the phase I study will be administered AIT-082 once a day for 7 consecutive days at doses of 100 to 2000 mg per dose [279422]. A limited double-blind, placebo-controlled phase I/II trial in 10 AD patients commenced in Canada in the first quarter of 1997. Treatment with 4000 mg improved memory in 60% of the patients within 3 h, as determined by the word recall test. A decrease in memory was observed in 80% of placebo-treated patients [257132]. A phase I US trial, conducted by the Alzheimer's Disease Cooperative Study, with funding from the National Institute of Aging, began in July 1997. AIT-082 was administered to eight healthy, elderly volunteers as part of an escalating single-dose study. Oral administration of AIT-082 was well-tolerated at high doses [284325] AIT-082 also enhanced memory function in both young adult and aged mice within 2 h of oral administration. Prophylactic treatment prevented or delayed the onset of age-induced memory deficits in mice when administered in drinking water. When memory impairment was produced by brain lesions, the drug restored memory performance and increased the genetic expression of neurotrophin-3 (NT-3), a natural protein growth factor associated with nerve cell function [284325]. AIT-082 appears to have at least three effects on the growth of PC-12 cells in culture. Firstly, it stimulates outgrowth of neurites, secondly it potentiates the growth effects of neurotrophin, and thirdly, it stimulates the synthesis of certain neurotrophins (nerve growth factor, neurotrophin-3 and fibroblast growth factor) and pleiotrophins by astrocytes. These progrowth mechanisms are thought to form the basis of the ability of AIT-082 to restore and prevent age-related working memory deficits in mice [195438]. In October 1997, further preclinical results were presented, demonstrating that treatment with AIT-082 produced an increase in neurotrophic factors following spinal cord injury in rats. This study was conducted at NeoTherapeutics and McMaster University, and was partially funded by the Amyotrophic Lateral Sclerosis Society of Canada. After 7 days of treatment, rats with spinal cord injuries showed an increase in the levels of CNTF and BDNF, naturally occurring growth factors in the spinal cord [267514].
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PMID:AIT-082 NeoTherapeutics Inc. 1846 24

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