Clinical trial NCT04842955: Modulators of Gamma tACS in Alzheimer's Disease (Mod-GammAD)
Official title: Interventional Cross-over Study to Evaluate the Modulators of Efficacy of Alternating Current Brain Stimulation (tACS) in Patients With Alzheimer's Disease
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Alzheimer Disease
Keywords: Alzheimer's disease
transcranial Alternating Current Stimulation
Gamma stimulation
tACS
Lead sponsor: Azienda Socio Sanitaria Territoriale degli Spedali Civili di Brescia
Sponsor class: OTHER
First posted: 2021-04-13
Enrollment: 60
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Primary purpose: TREATMENT

Brief summary: Brain oscillations are ubiquitous in the human brain and have been implicated in cognitive and behavioral states defined in precisely tuned neural networks. In neurodegenerative disorders, neurodegeneration is accompanied by changes in oscillatory activity leading to the emerging concept of neurological and psychiatric disorders as "oscillopathies". Alzheimer's disease, which accounts for the vast majority of age-related dementias, is characterised by a prominent disruption of oscillations in the gamma frequency band. The restoration of gamma oscillations by neural entrainment in animal models of Alzheimer's disease have shown a remarkable decrease in the pathological burden of amyloid and tau via increased microglial activity, resulting in a significant increase of cognitive performances.

Transcranial alternating current brain stimulation (tACS), is a neurophysiological method of non-invasive modulation of the excitability of the central nervous system that is having an increasingly numerous spectrum of potential therapeutic applications. Recent studies have demonstrated the effectiveness of this method in modulating the natural frequencies of cerebral oscillation, underlying multiple cognitive processes such as verbal memory, perception and working memory. On the basis of these premises, the treatment with gamma tACS is proposed in patients affected by Alzheimer's disease.

In this randomized, double-blind, sham-controlled, cross-over study, the investigators will evaluate the modulators of response on cognitive measure to a single stimulation with gamma tACS on the posterior parietal cortex in patients with Mild Cognitive Impairment due to Alzheimer's disease.

Detailed description: Brain oscillations are ubiquitous in the human brain and have been implicated in cognitive and behavioral states defined in precisely tuned neural networks. In neurodegenerative disorders, neurodegeneration is accompanied by changes in oscillatory activity leading to the emerging concept of neurological and psychiatric disorders as "oscillopathies". Alzheimer's disease, which accounts for the vast majority of age-related dementias, is characterised by a prominent disruption of oscillations in the gamma frequency band. The restoration of gamma oscillations by neural entrainment in animal models of Alzheimer's disease have shown a remarkable decrease in the pathological burden of amyloid and tau via increased microglial activity, resulting in a significant increase of cognitive performances.

Transcranial alternating current brain stimulation (tACS), is a neurophysiological method of non-invasive modulation of the excitability of the central nervous system that is having an increasingly numerous spectrum of potential therapeutic applications. Recent studies have demonstrated the effectiveness of this method in modulating the natural frequencies of cerebral oscillation, underlying multiple cognitive processes such as verbal memory, perception and working memory.

On the basis of these premises, the treatment with gamma tACS is proposed in patients affected by Alzheimer's disease.

In this randomized, double-blind, sham-controlled, cross-over study, the investigators will evaluate the modulators of response on cognitive measure to a single stimulation with gamma tACS on the posterior parietal cortex in patients with Mild Cognitive Impairment due to Alzheimer's disease.

Subjects will be randomized in two groups, one receiving a single treatment with gamma tACS (40 Hz) first and the other receiving sham stimulation. After one week the treatments will be exchanged. Patients will be evaluated with neuropsychological tests and neurophysiological measures of cholinergic transmission. Modulators of response, including cognitive reserve, baseline impairment, apo-E genotype, MRI measures of atrophy and connectivity, electric field modelling, will be considered.

Eligibility criteria: Inclusion Criteria:

- Mild Cognitive Impairment due to Alzheimer's disease (according to Albert et al., Alzheimers Dement 2011).

Exclusion Criteria:

* Cerebrovascular disorders, previous stroke, hydrocephalus, and intra-cranial mass documented by MRI.
* History of traumatic brain injury or other neurological diseases.
* Serious medical illness other than AD
* History of seizures
* Pregnancy
* Metal implants in the head (except dental fillings)
* Electronic implants (i.e. pace-maker, implanted medical pump)
* Age \<18 years

Primary outcomes:
measure: Changes in Rey Auditory Verbal Learning Test scores
timeFrame: Baseline (immediately before the intervention) - Immediately after the intervention
measure: Changes in Face-Name Associative Memory Test scores
timeFrame: During the intervention compared to sham comparator
Secondary outcomes:
measure: Change in SAI measurements
timeFrame: Baseline (immediately before the intervention) - Immediately after the intervention
Other outcomes:
Locations:
city: Brescia
country: Italy
facility: AO Spedali Civili
state: BS
Study officials:
affiliation: Azienda Ospedaliera Spedali Civili, Brescia
name: Barbara Borroni, MD
role: PRINCIPAL_INVESTIGATOR
affiliation: Azienda Ospedaliera Spedali Civili, Brescia
name: Alberto Benussi, MD
role: PRINCIPAL_INVESTIGATOR
References:
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citation: Iaccarino HF, Singer AC, Martorell AJ, Rudenko A, Gao F, Gillingham TZ, Mathys H, Seo J, Kritskiy O, Abdurrob F, Adaikkan C, Canter RG, Rueda R, Brown EN, Boyden ES, Tsai LH. Gamma frequency entrainment attenuates amyloid load and modifies microglia. Nature. 2016 Dec 7;540(7632):230-235. doi: 10.1038/nature20587.
citation: Adaikkan C, Middleton SJ, Marco A, Pao PC, Mathys H, Kim DN, Gao F, Young JZ, Suk HJ, Boyden ES, McHugh TJ, Tsai LH. Gamma Entrainment Binds Higher-Order Brain Regions and Offers Neuroprotection. Neuron. 2019 Jun 5;102(5):929-943.e8. doi: 10.1016/j.neuron.2019.04.011. Epub 2019 May 7.
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citation: Herrmann CS, Rach S, Neuling T, Struber D. Transcranial alternating current stimulation: a review of the underlying mechanisms and modulation of cognitive processes. Front Hum Neurosci. 2013 Jun 14;7:279. doi: 10.3389/fnhum.2013.00279. eCollection 2013.
citation: Benussi A, Cantoni V, Grassi M, Brechet L, Michel CM, Datta A, Thomas C, Gazzina S, Cotelli MS, Bianchi M, Premi E, Gadola Y, Cotelli M, Pengo M, Perrone F, Scolaro M, Archetti S, Solje E, Padovani A, Pascual-Leone A, Borroni B. Increasing Brain Gamma Activity Improves Episodic Memory and Restores Cholinergic Dysfunction in Alzheimer's Disease. Ann Neurol. 2022 Aug;92(2):322-334. doi: 10.1002/ana.26411. Epub 2022 Jun 6.