Theta Burst Stimulation

AbstractSpinocerebellar ataxia 38 (SCA 38) is an autosomal dominant disorder caused by conventional mutations in the ELOVL5 gene which encodes an enzyme involved in the synthesis of very long fatty acids, with a specific expression in cerebellar Purkinje cells. Three Italian families carrying the mutation, one of which is of Sardinian descent, have been identified and characterized. One session of cerebellar intermittent theta burst stimulation (iTBS) was applied to 6 affected members of the Sardinian family to probe motor cortex excitability measured by motor-evoked potentials (MEPs). Afterwards, patients were exposed to ten sessions of cerebellar real and sham iTBS in a cross-over study and clinical symptoms were evaluated before and after treatment by Modified International Cooperative Ataxia Rating Scale (MICARS). Moreover, serum BDNF levels were evaluated before and after real and sham cerebellar iTBS and the role of BDNF Val66Met polymorphism in influencing iTBS effect was explored. Present data show that one session of cerebellar iTBS was able to increase MEPs in all tested patients, suggesting an enhancement of the cerebello-thalamo-cortical pathway in SCA 38. MICARS scores were reduced after ten sessions of real cerebellar iTBS showing an improvement in clinical symptoms. Finally, although serum BDNF levels were not affected by cerebellar iTBS when considering all samples, segregating for genotype a difference was found between Val66Val and Val66Met carriers. These preliminary data suggest a potential therapeutic use of cerebellar iTBS in improving motor symptoms of SCA38.

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Intermittent Theta Burst Stimulation in Veterans with Mild Alcohol Use Disorder

Journal of Affective Disorders ◽

10.1016/j.jad.2021.06.039 ◽

2021 ◽

Author(s):

Melanie L. Bozzay ◽

Sydney Brigido ◽

Mascha van ’t Wout-Frank ◽

Emily Aiken ◽

Robert Swift ◽

...

Keyword(s):

Alcohol Use ◽

Alcohol Use Disorder ◽

Theta Burst Stimulation ◽

Burst Stimulation ◽

Theta Burst

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Behavioral effects of continuous theta-burst stimulation in macaque parietal cortex

Scientific Reports ◽

10.1038/s41598-021-83904-8 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Lara Merken ◽

Marco Davare ◽

Peter Janssen ◽

Maria C. Romero

Keyword(s):

Parietal Cortex ◽

High Intensity ◽

Theta Burst Stimulation ◽

Burst Stimulation ◽

Primate Model ◽

Power Grip ◽

Fitts Law ◽

Behavioral Evidence ◽

Theta Burst ◽

Continuous Theta Burst Stimulation

AbstractThe neural mechanisms underlying the effects of continuous Theta-Burst Stimulation (cTBS) in humans are poorly understood. Animal studies can clarify the effects of cTBS on individual neurons, but behavioral evidence is necessary to demonstrate the validity of the animal model. We investigated the behavioral effect of cTBS applied over parietal cortex in rhesus monkeys performing a visually-guided grasping task with two differently sized objects, which required either a power grip or a pad-to-side grip. We used Fitts’ law, predicting shorter grasping times (GT) for large compared to small objects, to investigate cTBS effects on two different grip types. cTBS induced long-lasting object-specific and dose-dependent changes in GT that remained present for up to two hours. High-intensity cTBS increased GTs for a power grip, but shortened GTs for a pad-to-side grip. Thus, high-intensity stimulation strongly reduced the natural GT difference between objects (i.e. the Fitts’ law effect). In contrast, low-intensity cTBS induced the opposite effects on GT. Modifying the coil orientation from the standard 45-degree to a 30-degree angle induced opposite cTBS effects on GT. These findings represent behavioral evidence for the validity of the nonhuman primate model to study the neural underpinnings of non-invasive brain stimulation.

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