Ae Young Lee

Background/Objectives: Central neuropathic pain (CNP) is difficult to manage, and comparative evidence for non-invasive brain stimulation is limited. We explored the short-term efficacy and safety of repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS) in CNP. Methods: In this randomized, sham-controlled crossover trial, 26 patients were allocated to active or sham stimulation and received high-frequency rTMS (10 Hz, 2000 pulses/session) and anodal tDCS (2 mA, 30 min) over the primary motor cortex for five days each, separated by a 4-week washout. The primary outcome was change in Numerical Rating Scale (NRS) pain intensity at 1 and 4 weeks, analysed using factorial linear mixed-effects models with and without age adjustment. Results: At 1 week, the difference between active and sham rTMS was 0.76 points (95% CI −0.005 to 1.53; p = 0.051) and 0.42 points after age adjustment (95% CI −0.37 to 1.21; p = 0.30). Active tDCS did not differ from sham tDCS, and active rTMS did not differ from active tDCS. No significant differences were found at 4 weeks or in responder analyses. No serious adverse events occurred. Conclusions: In this small exploratory trial, neither rTMS nor tDCS showed statistically significant superiority over modality-matched sham, and no difference between modalities was demonstrated. Adequately powered trials are needed.

Background and Purpose: Amyloid positron emission tomography (PET) is a crucial diagnostic tool for Alzheimer's disease (AD), but its application is constrained by cost and accessibility. This study aimed to create a practical composite index to predict cerebral amyloid positivity in patients with cognitive impairment. Methods: We included patients with mild cognitive impairment or early-stage AD who underwent amyloid PET. Various combinations of clinical and imaging variables were assessed through receiver operating characteristic analysis to identify the optimal model for predicting amyloid positivity. The Amyloid Beta Composite (ABC) index, a risk scoring model, was developed using logistic regression and a weighted scoring system. We evaluated the ABC index's performance based on accuracy, sensitivity, and specificity, and conducted internal validation using a chronological split-sample from the same cohort. Results: We analyzed a total of 223 patients. The best-performing model incorporated five variables: Mini-Mental State Examination (MMSE), secondary memory recall from the modified MMSE, Clinical Dementia Rating-Sum of Boxes, medial temporal lobe atrophy, and apolipoprotein E genotype. This model demonstrated excellent performance in the development group (area under the curve [AUC], 0.88; 95% confidence interval, 0.82-0.94). In the validation group, the ABC index achieved an AUC of 0.74, with an accuracy of 0.70, sensitivity of 0.63, and specificity of 0.78. Conclusions: The ABC index, utilizing commonly accessible clinical data, serves as a simple and practical screening tool for predicting cerebral amyloid deposition. It may aid in patient selection for amyloid PET, anti-amyloid therapies, and clinical trials, thereby reducing unnecessary imaging.

Kwon HS, et al. Dement Neurocogn Disord. 2023 Jul;22(3):100-108. https://doi.org/10.12779/dnd.2023.22.3.100

Colony-stimulating factor 1 receptor (CSF1R)-related leukoencephalopathy is one of the most common causes of adult-onset leukodystrophy and is caused by mutation of the CSF1R gene. Brain magnetic resonance imaging (MRI) findings in asymptomatic patients have not been well recognized. We report on the case of a patient with CSF1R-related leukoencephalopathy who had a novel missense variant of the CSF1R gene with a family history of early onset dementia. This is a representative case of CSF1R-related leukoencephalopathy, which shows the progression of brain MRI and cognitive decline from an asymptomatic state.

Transcranial magnetic stimulation (TMS) is a safe and noninvasive tool for investigating the cortical excitability of the human brain and the neurophysiological functions of GABAergic, glutamatergic, and cholinergic neural circuits. Neurophysiological biomarkers based on TMS parameters can provide information on the pathophysiology of dementia, and be used to diagnose Alzheimer’s disease and differentiate different types of dementia. This review introduces the basic principles of TMS, TMS devices and stimulating paradigms, several neurophysiological measurements, and the clinical implications of TMS for Alzheimer’s disease.

Sohn EH, et al. J Clin Neurol. 2021 Jul;17(3):463-469. https://doi.org/10.3988/jcn.2021.17.3.463

Lee J, et al. Dement Neurocogn Disord. 2020 Jun;19(2):65-73. https://doi.org/10.12779/dnd.2020.19.2.65

Background: Magnetic resonance imaging (MRI) is a useful tool to predict the diagnosis and progression of Alzheimer’s disease (AD), especially for primary physicians. However, the correlation between baseline MRI findings and AD progression has not b