Neural Mechanism of Repeated Transcranial Magnetic Stimulation to Enhance Visual Working Memory in Elderly Individuals With Subjective Cognitive Decline.

Visual working memory (VWM), the core process inherent to many advanced cognitive processes, deteriorates with age. Elderly individuals usually experience defects in the processing of VWM. The dorsolateral prefrontal cortex is a key structure for the top-down control of working memory processes. Many studies have shown that repeated transcranial magnetic stimulation (rTMS) improves VWM by modulating the excitability of neurons in the target cortical region, though the underlying neural mechanism has not been clarified. Therefore, this study sought to assess the characteristics of brain memory function post-rTMS targeting the left dorsolateral prefrontal cortex. The study stimulated the left dorsolateral prefrontal cortex in elderly individuals by performing a high-frequency rTMS protocol and evaluated behavioral performance using cognitive tasks and a VWM task. Based on the simultaneously recorded electroencephalogram signals, event-related potential and event-related spectral perturbation analysis techniques were used to investigate the variation characteristics of event-related potential components' (N2PC and CDA) amplitudes and neural oscillations in elderly individuals to elucidate the effect of high-frequency rTMS. The results found that rTMS enhanced VWM performance and significantly improved attention and executive function in elderly individuals with subjective cognitive decline. We therefore speculate that rTMS enhances VWM by increasing the N2PC and CDA amplitude, alongside increasing ß oscillation activity. This would improve the attention and allocation of resources in elderly individuals such as to improve an individual's VWM.

Rarely fast progressive memory loss diagnosed as Creutzfeldt-Jakob disease: A case report.

BACKGROUND: Creutzfeldt-Jakob disease (CJD) is a rare degenerative disease of the central nervous system that can be contagious or hereditary and is a rare cause of rapidly progressive dementia. It almost always results in death within 1-2 years from symptom onset. CASE SUMMARY: Here, we report the case of a 57-year-old male who initially experienced dizziness followed by a 1-mo fast decline in memory function. He presented to the local hospital and underwent magnetic resonance imaging and cerebrospinal fluid (CSF) examination, with no definitive diagnosis. However, the symptoms of progressive forgetting worsened. In addition, he exhibited progressive involuntary tremor of the limbs. Then, he came to our hospital, and according to the results of CSF examination, electroencephalography (EEG) and magnetic resonance imaging (MRI) tests and clinical manifestations of cerebellar ataxia, dementia, and myoclonus that rapidly progressed, with a short duration of illness, he was finally diagnosed with sporadic CJD (sCJD). CONCLUSION: This case report aims to create awareness among physicians to emphasize auxiliary examination, CSF examination, EEG and MRI tests and recognition of cerebellar ataxia, dementia, and myoclonus that rapidly progress to prompt pursuit of an early diagnosis and identification of sCJD and to reduce complications.