The impact of rTMS over the dorsolateral prefrontal cortex on cognitive processing

Repetitive Transcranial Magnetic Stimulation in Delirium: A Double-blind, Randomized, Sham-controlled, Pilot Study

INTRODUCTION

Delirium is a fatal but potentially reversible disorder of the central nervous system that imposes high costs on health systems. This study aims to evaluate the effect of intermittent theta-burst stimulation on the severity and course of delirium disorder.

METHODS

This is a double-blind, randomized, sham-controlled pilot study. The study participants were randomly allocated into the active (active intermittent theta-burst stimulation) and sham groups. The severity of delirium was assessed 15 minutes before the intervention and 15 minutes after that by the Neelon and Champagne (NEECHAM) confusion scale.

RESULTS

In the active group, total and subscale scores of NEECHAM significantly decreased after intervention (P<0.05). Although no statistical difference was found in the control group regarding the subscale scores of NEECHAM, the difference in the total scores before and after the sham intervention was statistically significant.

CONCLUSION

Carrying one session of repetitive transcranial magnetic stimulation on the left dorsolateral prefrontal cortex can reduce the delirium severity in a short period, although it will not decrease the number of delirium cases three days after the intervention.

HIGHLIGHTS

Delirium is a CNS disorder;Delirium treatment is based on pharmacological and non-pharmacological;rTMS is quasi-modern treatment of neurocognitive disorders.

PLAIN LANGUAGE SUMMARY

Delirium is fatal but reversible disorder. regarding the restrictions of routine treatments of delirium and by considering the cognition disturbances as the core symptom of delirium, and the positive effect of rTMS on cognition functions. we hypothesized that rTMS could be effective in the treatment of delirium.

Theta-Burst Stimulation Is Able to Impact Cognitive Processing: A P300 and Neuropsychological Test Study

INTRODUCTION

Theta-burst stimulation (TBS) is a safe non-invasive neurostimulation technique used to improve cognitive and neuropsychiatric impairments. Combined outcome evaluation using event-related potentials (ERPs) and neuropsychological tests may allow a more thorough assessment of TBS treatment efficacy; however, some mixed results have been found, and their use remains scarce. Our main objective was to evaluate whether a session of TBS to the left dorsolateral prefrontal cortex (DLPFC) can impact upon the performance of both neuropsychological and neurophysiological tests.

METHODS

This double-blind sham-controlled study involved 28 healthy adults, between 18 and 30 years. Volunteers were randomly allocated to receive excitatory (intermittent [iTBS]), inhibitory (continuous TBS [cTBS]) or sham stimulation on the left DLPFC. Subjects were evaluated using ERPs (auditory oddball paradigm P300) and neuropsychological tests (Trail making test [TMT] and Stroop test of words and colours [STWC]), using a pre-post stimulation protocol.

RESULTS

Inhibitory stimulation led to significantly delayed P300 peak latencies (p < 0.001), with no consistent change in N2P3 amplitudes. cTBS also significantly influenced the expected group performance in Stroop C and Stroop interference (p = 0.025) compared to the iTBS and sham groups. No significant results were found in TMT tests after TBS.

CONCLUSION

Our results suggest that P300 and specific Stroop colour and words test parameters can be similarly influenced by the same TBS protocol. This emphasizes the importance of mixed evaluation using neuropsychological and neurophysiological resources in research associated with the use of transcranial magnetic stimulation and cognition.

Repetitive Transcranial Magnetic Stimulation, Cognition, and Multiple Sclerosis: An Overview

Multiple sclerosis (MS) affects cognition in the majority of patients. A major aspect of the disease is brain volume loss (BVL), present in all phases and types (relapsing and progressive) of the disease and linked to both motor and cognitive disabilities. Due to the lack of effective pharmacological treatments for cognition, cognitive rehabilitation and other nonpharmacological interventions such as repetitive transcranial magnetic stimulation (rTMS) have recently emerged and their potential role in functional connectivity is studied. With recently developed advanced neuroimaging and neurophysiological techniques, changes related to alterations of the brain's functional connectivity can be detected. In this overview, we focus on the brain's functional reorganization in MS, theoretical and practical aspects of rTMS utilization in humans, and its potential therapeutic role in treating cognitively impaired MS patients.