The facilitative effect of transcranial direct current stimulation on visuospatial working memory in patients with diabetic polyneuropathy: A pre-post sham-controlled study

Research output: Contribution to journalArticle

11 Citations (Scopus)

Abstract

Diabetes mellitus can lead to diabetic polyneuropathy (DPN) and cognitive deficits that manifest as peripheral and central neuropathy, respectively. In this study we investigated the relationship between visuospatial working memory (VSWM) capacity and DPN severity, and attempted to improve VSWM in DPN patients via the use of transcranial direct current stimulation (tDCS). Sixteen DPN patients and 16 age- and education-matched healthy control subjects received Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV) and Montreal Cognitive Assessment (MOCA) for baseline cognitive assessment. A forward- and backward-recall computerized Corsi block tapping task (CBT), both with and without a concurrent motor interference task was used to measure VSWM capacity. Each DPN patient underwent a pre-treatment CBT, followed by tDCS or sham treatment, then a post-treatment CBT on two separate days. We found that although patients with severe DPN (Dyck’s grade 2a or 2b) showed comparable general intelligence scores on WAIS-IV as their age- and education-matched healthy counterparts, they nonetheless showed mild cognitive impairment (MCI) on MOCA and working memory deficit on digit-span test of WAIS-IV. Furthermore, patients’ peripheral nerve conduction velocity (NCV) was positively correlated with their VSWM span in the most difficult CBT condition that involved backward-recall with motor interference such that patients with worse NCV also had lower VSWM span. Most importantly, anodal tDCS over the right DLPFC was able to improve low-performing patients’ VSWM span to be on par with the high-performers, thereby eliminating the correlation between NCV and VSWM. In summary, these findings suggest that (1) MCI and severe peripheral neuropathy can coexist with unequal severity in diabetic patients, the positive correlation of VSWM and NCV suggests a link between peripheral and central neuropathies, and (3) anodal tDCS over the right DLPFC can improve DPN patients ’ VSWM, particularly for the low-performing patients.

Original languageEnglish
JournalFrontiers in Human Neuroscience
Volume10
Issue numberSEP2016
DOIs
Publication statusPublished - 2016 Sep 28

Fingerprint

Diabetic Neuropathies
Short-Term Memory
Neural Conduction
Peripheral Nervous System Diseases
Intelligence
Transcranial Direct Current Stimulation
Education
Memory Disorders
Peripheral Nerves
Diabetes Mellitus
Healthy Volunteers
Placebos

All Science Journal Classification (ASJC) codes

  • Neuropsychology and Physiological Psychology
  • Neurology
  • Psychiatry and Mental health
  • Biological Psychiatry
  • Behavioral Neuroscience

Cite this

@article{9507930d22014fcea37916df2f819504,
title = "The facilitative effect of transcranial direct current stimulation on visuospatial working memory in patients with diabetic polyneuropathy: A pre-post sham-controlled study",
abstract = "Diabetes mellitus can lead to diabetic polyneuropathy (DPN) and cognitive deficits that manifest as peripheral and central neuropathy, respectively. In this study we investigated the relationship between visuospatial working memory (VSWM) capacity and DPN severity, and attempted to improve VSWM in DPN patients via the use of transcranial direct current stimulation (tDCS). Sixteen DPN patients and 16 age- and education-matched healthy control subjects received Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV) and Montreal Cognitive Assessment (MOCA) for baseline cognitive assessment. A forward- and backward-recall computerized Corsi block tapping task (CBT), both with and without a concurrent motor interference task was used to measure VSWM capacity. Each DPN patient underwent a pre-treatment CBT, followed by tDCS or sham treatment, then a post-treatment CBT on two separate days. We found that although patients with severe DPN (Dyck’s grade 2a or 2b) showed comparable general intelligence scores on WAIS-IV as their age- and education-matched healthy counterparts, they nonetheless showed mild cognitive impairment (MCI) on MOCA and working memory deficit on digit-span test of WAIS-IV. Furthermore, patients’ peripheral nerve conduction velocity (NCV) was positively correlated with their VSWM span in the most difficult CBT condition that involved backward-recall with motor interference such that patients with worse NCV also had lower VSWM span. Most importantly, anodal tDCS over the right DLPFC was able to improve low-performing patients’ VSWM span to be on par with the high-performers, thereby eliminating the correlation between NCV and VSWM. In summary, these findings suggest that (1) MCI and severe peripheral neuropathy can coexist with unequal severity in diabetic patients, the positive correlation of VSWM and NCV suggests a link between peripheral and central neuropathies, and (3) anodal tDCS over the right DLPFC can improve DPN patients ’ VSWM, particularly for the low-performing patients.",
author = "Yi-Jen Wu and Philip Tseng and Han-Wei Huang and Jon-Fan Hu and Juan, {Chi Hung} and Kuei-Sen Hsu and Chou-Ching Lin",
year = "2016",
month = "9",
day = "28",
doi = "10.3389/fnhum.2016.00479",
language = "English",
volume = "10",
journal = "Frontiers in Human Neuroscience",
issn = "1662-5161",
publisher = "Frontiers Research Foundation",
number = "SEP2016",

}

TY - JOUR

T1 - The facilitative effect of transcranial direct current stimulation on visuospatial working memory in patients with diabetic polyneuropathy

T2 - A pre-post sham-controlled study

AU - Wu, Yi-Jen

AU - Tseng, Philip

AU - Huang, Han-Wei

AU - Hu, Jon-Fan

AU - Juan, Chi Hung

AU - Hsu, Kuei-Sen

AU - Lin, Chou-Ching

PY - 2016/9/28

Y1 - 2016/9/28

N2 - Diabetes mellitus can lead to diabetic polyneuropathy (DPN) and cognitive deficits that manifest as peripheral and central neuropathy, respectively. In this study we investigated the relationship between visuospatial working memory (VSWM) capacity and DPN severity, and attempted to improve VSWM in DPN patients via the use of transcranial direct current stimulation (tDCS). Sixteen DPN patients and 16 age- and education-matched healthy control subjects received Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV) and Montreal Cognitive Assessment (MOCA) for baseline cognitive assessment. A forward- and backward-recall computerized Corsi block tapping task (CBT), both with and without a concurrent motor interference task was used to measure VSWM capacity. Each DPN patient underwent a pre-treatment CBT, followed by tDCS or sham treatment, then a post-treatment CBT on two separate days. We found that although patients with severe DPN (Dyck’s grade 2a or 2b) showed comparable general intelligence scores on WAIS-IV as their age- and education-matched healthy counterparts, they nonetheless showed mild cognitive impairment (MCI) on MOCA and working memory deficit on digit-span test of WAIS-IV. Furthermore, patients’ peripheral nerve conduction velocity (NCV) was positively correlated with their VSWM span in the most difficult CBT condition that involved backward-recall with motor interference such that patients with worse NCV also had lower VSWM span. Most importantly, anodal tDCS over the right DLPFC was able to improve low-performing patients’ VSWM span to be on par with the high-performers, thereby eliminating the correlation between NCV and VSWM. In summary, these findings suggest that (1) MCI and severe peripheral neuropathy can coexist with unequal severity in diabetic patients, the positive correlation of VSWM and NCV suggests a link between peripheral and central neuropathies, and (3) anodal tDCS over the right DLPFC can improve DPN patients ’ VSWM, particularly for the low-performing patients.

AB - Diabetes mellitus can lead to diabetic polyneuropathy (DPN) and cognitive deficits that manifest as peripheral and central neuropathy, respectively. In this study we investigated the relationship between visuospatial working memory (VSWM) capacity and DPN severity, and attempted to improve VSWM in DPN patients via the use of transcranial direct current stimulation (tDCS). Sixteen DPN patients and 16 age- and education-matched healthy control subjects received Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV) and Montreal Cognitive Assessment (MOCA) for baseline cognitive assessment. A forward- and backward-recall computerized Corsi block tapping task (CBT), both with and without a concurrent motor interference task was used to measure VSWM capacity. Each DPN patient underwent a pre-treatment CBT, followed by tDCS or sham treatment, then a post-treatment CBT on two separate days. We found that although patients with severe DPN (Dyck’s grade 2a or 2b) showed comparable general intelligence scores on WAIS-IV as their age- and education-matched healthy counterparts, they nonetheless showed mild cognitive impairment (MCI) on MOCA and working memory deficit on digit-span test of WAIS-IV. Furthermore, patients’ peripheral nerve conduction velocity (NCV) was positively correlated with their VSWM span in the most difficult CBT condition that involved backward-recall with motor interference such that patients with worse NCV also had lower VSWM span. Most importantly, anodal tDCS over the right DLPFC was able to improve low-performing patients’ VSWM span to be on par with the high-performers, thereby eliminating the correlation between NCV and VSWM. In summary, these findings suggest that (1) MCI and severe peripheral neuropathy can coexist with unequal severity in diabetic patients, the positive correlation of VSWM and NCV suggests a link between peripheral and central neuropathies, and (3) anodal tDCS over the right DLPFC can improve DPN patients ’ VSWM, particularly for the low-performing patients.

UR - http://www.scopus.com/inward/record.url?scp=84989295924&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84989295924&partnerID=8YFLogxK

U2 - 10.3389/fnhum.2016.00479

DO - 10.3389/fnhum.2016.00479

M3 - Article

AN - SCOPUS:84989295924

VL - 10

JO - Frontiers in Human Neuroscience

JF - Frontiers in Human Neuroscience

SN - 1662-5161

IS - SEP2016

ER -