Cognitive Training and Transcranial Direct Current Stimulation in Mild Cognitive Impairment: A Randomized Pilot Trial.

BACKGROUND: Transcranial direct current stimulation (tDCS), a non-invasive stimulation, represents a potential intervention to enhance cognition across clinical populations including Alzheimer's disease and mild cognitive impairment (MCI). This randomized clinical trial in MCI investigated the effects of anodal tDCS (a-tDCS) delivered to left inferior frontal gyrus (IFG) combined with gist-reasoning training (SMART) versus sham tDCS (s-tDCS) plus SMART on measures of cognitive and neural changes in resting cerebral blood flow (rCBF). We were also interested in SMART effects on cognitive performance regardless of the tDCS group. METHODS: Twenty-two MCI participants, who completed the baseline cognitive assessment (T1), were randomized into one of two groups: a-tDCS + SMART and s-tDCS + SMART. Of which, 20 participants completed resting pCASL MRI scan to measure rCBF. Eight SMART sessions were administered over 4 weeks with a-tDCS or s-tDCS stimulation for 20 min before each session. Participants were assessed immediately (T2) and 3-months after training (T3). RESULTS: Significant group × time interactions showed cognitive gains at T2 in executive function (EF) measure of inhibition [DKEFS- Color word (p = 0.047)], innovation [TOSL (p = 0.01)] and on episodic memory [TOSL (p = 0.048)] in s-tDCS + SMART but not in a-tDCS + SMART group. Nonetheless, the gains did not persist for 3 months (T3) after the training. A voxel-based analysis showed significant increase in regional rCBF in the right middle frontal cortex (MFC) (cluster-wise p = 0.05, k = 1,168 mm3) in a-tDCS + SMART compared to s-tDCS + SMART. No significant relationship was observed between the increased CBF with cognition. Irrespective of group, the combined MCI showed gains at T2 in EF of conceptual reasoning [DKEFS card sort (p = 0.033)] and category fluency [COWAT (p = 0.055)], along with gains at T3 in EF of verbal fluency [COWAT (p = 0.009)]. CONCLUSION: One intriguing finding is a-tDCS to left IFG plus SMART increased blood flow to right MFC, however, the stimulation seemingly blocked cognitive benefits of SMART on EF (inhibition and innovation) and episodic memory compared to s-tDCS + SMART group. Although the sample size is small, this paper contributes to growing evidence that cognitive training provides a way to significantly enhance cognitive performance in adults showing memory loss, where the role of a-tDCS in augmenting these effects need further study.

A blood screening test for Alzheimer's disease.

INTRODUCTION: This study combined data across four independent cohorts to examine the positive and negative predictive values of an Alzheimer's disease (AD) blood test if implemented in primary care. METHODS: Blood samples from 1329 subjects from multiple independent, multiethnic, community-based, and clinic-based cohorts were analyzed. A "locked-down" referent group of 1128 samples was generated with 201 samples randomly selected for validation purposes. Random forest analyses were used to create the AD blood screen. Positive (PPV) and negative (NPV) predictive values were calculated. RESULTS: In detecting AD, PPV was 0.81, and NPV was 0.95 while using the full AD blood test. When detecting mild cognitive impairment, PPV and NPV were 0.74 and 0.93, respectively. Preliminary analyses were conducted to detect any "neurodegenerative disease". The full 21-protein AD blood test yielded a PPV of 0.85 and NPV of 0.94. DISCUSSION: The present study creates the first-ever multiethnic referent sample that spans community-based and clinic-based populations for implementation of an AD blood screen.

Remote Neuropsychological Assessment in Rural American Indians with and without Cognitive Impairment.

OBJECTIVE: To determine the feasibility and reliability of a brief battery of standard neuropsychological tests administered via video teleconference (VTC) to a sample of rural American Indians compared with traditional face-to-face administration. METHODS: The sample consisted of 84 participants from the Choctaw Nation in Oklahoma, including 53 females and 31 males [M age = 64.89 (SD = 9.73), M education = 12.58 (SD = 2.35)]. Of these, 29 had a diagnosis of mild cognitive impairment or dementia, and 55 were cognitively normal. Tests included the MMSE, Clock Drawing, Digit Span Forward and Backward, Oral Trails, Hopkins Verbal Learning Test-Revised, Letter and Category Fluency, and a short form Boston Naming Test. Alternative forms of tests were administered in counterbalanced fashion in both face-to-face and VTC conditions. Intraclass correlation coefficients (ICCs) were used to compare test scores between test conditions across the entire sample. RESULTS: All ICCs were significant (p< .0001) and ranged from 0.65 (Clock Drawing) to 0.93 (Boston Naming Test), with a mean ICC of 0.82. CONCLUSION: Results add to the expanding literature supporting the feasibility and reliability of remote videoconference-based neuropsychological test administration and extend findings to American Indians.

Multilevel intramedullary spinal neurocysticercosis with eosinophilic meningitis.

BACKGROUND: Cysticercal involvement of the spinal cord is a very rare form of neurocysticercosis. Intramedullary cysts are even less common. OBJECTIVE: To describe a novel presentation of multilevel intramedullary neurocysticercosis with eosinophilic meningitis. DESIGN: Case report. PATIENT: A 35-year-old man with a history of cerebral neurocysticercosis who presented with both cauda equina and Brown-Sequard syndromes associated with cerebrospinal fluid findings of eosinophilic meningitis. RESULTS: Magnetic resonance imaging confirmed the multilevel intramedullary cord lesions. The patient was treated medically with dexamethasone and albendazole and had a good recovery. CONCLUSION: Intramedullary neurocysticercosis should be considered as a potentially treatable cause of multilevel spinal lesions with subacute meningitis.