Cerebellar Metaplasticity in the Swallowing Motor System

University of Manchester

Status: Not yet enrolling

Conditions: Dysphagia; Swallowing

Treatments: Device: Cerebellar rTMS

Study type: Interventional

Funder types: Other

Identifiers

NCT06721533

341596

Details and patient eligibility

About

Dysphagia is common and leads to significant morbidity and mortality within healthcare settings. Current approaches to dysphagia management involve altering the consistency of food and fluids. However, these approaches are not supported by a robust evidence base. Repetitive transcranial magnetic stimulation (rTMS) offers a non-invasive way to manipulate neuroelectric activity within the brain. Within the swallowing motor system, rTMS at a frequency of 5Hertz (Hz) and above is excitatory while 1Hz is suppressive.

Cortical rTMS targeting pharyngeal motor areas can alter brain activity and swallowing behaviour in healthy participants and has been shown to improve post-stroke dysphagia (PSD). Despite this, it has a small seizure risk. Cerebellar rTMS is a newer and safer technique which is more easily targeted and is effective at altering swallowing related brain activity and behaviour. Recent studies have also shown it can improve PSD.

Critically, individual responsiveness to rTMS is variable, potentially reducing its effectiveness. Metaplasticity whereby the brain is preconditioned with a neuroelectric stimulus before the treating stimulus is administered is a potential way of reducing variability. Metaplasticity has recently been shown to improve responses within the swallowing motor system following cortical rTMS. However, to date no cerebellar rTMS study has applied this approach. This is a gap in our understanding which will need to be addressed.

The overarching aim of the study is to develop a less variable and more effective treatment for neurogenic dysphagia. More specifically the study objectives are to establish:

1. Whether 10Hz Cer-rTMS delivered over hemispheric pharyngeal areas can induce SMS metaplastic changes in healthy participants.
2. If a cerebellar rTMS metaplastic stimulation protocol can affect swallowing behaviour.

Enrollment: 20 estimated patients

Sex: All

Ages: 18+ years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

Healthy participants > 18 years of age

Exclusion criteria

Exclusion criteria will be the presence or a history of:

1. Epilepsy
2. Cardiac pacemaker
3. Previous brain surgery
4. Previous swallowing problems
5. The use of medication which acts on the central nervous system
6. Any implanted metal in the head
7. Pregnancy (self-declared)

Trial design

Primary purpose: Other

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: Single Blind

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20 participants in 10 patient groups

Arm 1

Experimental group

Description:

1. Real 10 Hz cerebellar rTMS (250 pulses) to the right cerebellar hemisphere immediately followed by 1 Hz cerebellar rTMS (600 pulses) to the same area. Pharyngeal motor evoked potential (PMEP) amplitude measured

Treatment:

Device: Cerebellar rTMS

Arm 2

Experimental group

Description:

2. Sham 10 Hz cerebellar rTMS (250 pulses) to the right cerebellar hemisphere immediately followed by 1 Hz cerebellar rTMS (600 pulses) to the same area. PMEP amplitude measured

Treatment:

Device: Cerebellar rTMS

Arm 3

Experimental group

Description:

3. Real 10 Hz cerebellar rTMS (250 pulses) to the right cerebellar hemisphere followed after 45 minutes by 1 Hz cerebellar rTMS (600 pulses) to the same area. PMEP amplitude measured

Treatment:

Device: Cerebellar rTMS

Arm 4

Experimental group

Description:

4. Real 10 Hz cerebellar rTMS (250 pulses) to the right cerebellar hemisphere followed after 90 minutes by 1 Hz cerebellar rTMS (600 pulses) to the same area. PMEP amplitude measured

Treatment:

Device: Cerebellar rTMS

Arm 5

Experimental group

Description:

5. Real 1 Hz cerebellar rTMS (600 pulses) to the right cerebellar hemisphere immediately followed by 10 Hz cerebellar rTMS (250 pulses) to the same area. PMEP amplitude measured

Treatment:

Device: Cerebellar rTMS

Arm 6

Experimental group

Description:

6. Sham 1 Hz cerebellar rTMS (600 pulses) to the right cerebellar hemisphere immediately followed by 10 Hz cerebellar rTMS (250 pulses) to the same area. PMEP amplitude measured

Treatment:

Device: Cerebellar rTMS

Arm 7

Experimental group

Description:

7. Real 1 Hz cerebellar rTMS (600 pulses) to the right cerebellar hemisphere followed after 30 minutes by 10 Hz cerebellar rTMS (250 pulses) to the same area. PMEP amplitude measured

Treatment:

Device: Cerebellar rTMS

Arm 8

Experimental group

Description:

8. Real 1 Hz cerebellar rTMS (600 pulses) to the right cerebellar hemisphere followed after 60 minutes by 10 Hz cerebellar rTMS (250 pulses) to the same area. PMEP amplitude measured

Treatment:

Device: Cerebellar rTMS

Arm 9

Experimental group

Description:

Most excitatory metaplastic protocol (comparing effects of arms 1-8 against one another) to right cerebellar hemisphere. Swallowing accuracy measurements.

Treatment:

Device: Cerebellar rTMS

Arm 10

Experimental group

Description:

Single dose cerebellar rTMS to right hemisphere. Swallowing accuracy measurements.

Treatment:

Device: Cerebellar rTMS