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memory impairment

Etiology: - mild cognitive impairment - dementia - delirium - amnesia - hypothyroidism - often associated with old age Epidemiology: - 42% of adults who discuss memory problems with their provider receive treatment (therapy, medications)* [4] * no discussion on effectiveness of therapy or medications [4] Pathology: - diminished firing rates of involved neurons [1] - atrophy in the medial prefrontal cortex with normal aging leads to less slow-wave sleep, which impairs medial prefrontal cortex to hippocampus connectivity leaving episodic memory stuck in the hippocampus instead of being transformed into more-stable long-term memory [2] - working memory declines in older adults (60-76 years vs 20-29 years) [6] - deficits are linked to desynchronization of rhythmic activity between the prefrontal regions that evaluate information & the temporal regions that store it - semantic memory & procedural memory generally remain stable with increasing age [7] - working memory, episodic memory, processing speed, prospective memory, & recall of new text information generally decline with age [7] Clinical manifestations: - often in association with other features of cognitive impairment. Management: - targeted high-definition transcranial alternating-current stimulation tuned to individual brain network dynamics for 25 minutes rapidly normalizes cortical-rhythm disruptions, restoring phase synchronization typical of younger adults [6] - phase coordination associated with improvement in accuracy of working memory, persisting at least 50-minutes poststimulation [6] - distraction with unrelated information in the same modality might enable patients to use alternative, more efficient memory pathway (alternative to hippocampal encoding) [3] Comparative biology: - overexpression of FKBP1b in hippocampus of rats reverses age- associated memory impairment & neuronal Ca+2 dysregulation [5] - in normal rats a functional gradient occurs in CA3 along the transverse axis, as pattern-separated outputs (proximal CA3) with transition to pattern- completed outputs (distal CA3) - normal transition from pattern separation to pattern completion along the CA3 transverse axis is disrupted in aged memory-impaired rats [8]

Related

amnesia memory memory assessment Memory Impairment Study

Specific

forgetting memory impairment in Alzheimer's disease subjective memory problems in the elderly

General

cognitive impairment

References

  1. Wang M et al. Neuronal basis of age-related working memory decline. Nature. 2011 Jul 27;476(7359):210-3. doi: 10.1038/nature10243. PMID: 21796118
  2. Mander BA et al. Prefrontal atrophy, disrupted NREM slow waves and impaired hippocampal-dependent memory in aging. Nat Neurosci 2013 Jan 27 PMID: 23354332 http://www.nature.com/neuro/journal/v16/n3/full/nn.3324.html
  3. Cashdollar N et al. Alleviating memory impairment through distraction. J Neurosci 2013 Nov 27; 33:19012 PMID: 24285905 http://www.jneurosci.org/content/33/48/19012
  4. Centers for Disease Control & Prevention (CDC) Preventing Chronic Disease. Routine Check-Ups and Other Factors Affecting Discussions With a Health Care Provider About Subjective Memory Complaints, Behavioral Risk Factor Surveillance System, 21 States, 2011. CME ACTIVITY - Volume 13 - January 28, 2016 http://www.cdc.gov/pcd/issues/2016/15_0471.htm
  5. Gant JC, Blalock EM, Chen KC et al FK506-Binding Protein 12.6/1b, a negative regulator of [Ca2+], rescues memory and restores genomic regulation in the hippocampus of aging rats. J Neurosci. 2017 Dec 18, 2234-17 PMID: 29255009 http://www.jneurosci.org/content/early/2017/12/18/JNEUROSCI.2234-17.2017
  6. Reinhart RMG, Nguyen JA. Working memory revived in older adults by synchronizing rhythmic brain circuits. Nat Neurosci 2019 Apr 8; PMID: 30962628 https://www.nature.com/articles/s41593-019-0371-x
  7. Lutsep HL Fast Five Quiz: Memory Loss and Cognitive Impairment Medscape. April 28, 2021 https://reference.medscape.com/viewarticle/949619
  8. Jhung L Scientists Find Brain Mechanism Behind Age-Related Memory Loss. Medscape. July 5, 2022 https://www.medscape.com/viewarticle/976566 - Lee H, Wang Z, Tillekeratne A et al Loss of functional heterogeneity along the CA3 transverse axis in aging. Current Biology. 2022 32(12):2681-2693, June 20 PMID: 35597233 PMCID: PMC9233142 Free PMC article https://www.cell.com/current-biology/fulltext/S0960-9822(22)00713-8
  9. Forgetfulness: It's Not Always What You Think http://www.niapublications.org/engagepages/forgetfulness.asp