Study of EEG and Nasal Stimulus in Olfactory Disorders

NCT06589375 | Not Yet Recruiting DMC

• 1 other identifier: ID6911
• Study Type: interventional
• Target: 1,000
• Locations: 0 countries
• Sites: N/A

Brief Summary

Neuroscent aims to analyze EEG signals induced by olfactory stimuli in individuals with normal and impaired olfactory functions, with a focus on patients with tinnitus. The study seeks to develop reliable diagnostic methods using EEG to differentiate between normosmic and hyposmic subjects during olfactory tests, potentially enhancing our understanding of the brain's response to olfactory stimuli. This 24-month interventional study with a device to be patented will involve 1000 participants and aims to establish more effective diagnostic and therapeutic tools for olfactory disorders

Conditions

Olfaction Disorders

Keywords

Olfactory stimuli; EEG; Tinnitus; Olfactory disorders; Smell impairment; Olfactometry; Brain waves

Outcome Measures

Primary Outcomes (5)

• Enrollment and data collection

  During this period, 1000 participants \> 18 y/o will be recruited and divided into four distinct groups: normosmics (550), hyposmics (150), tinnitus patients with hyposmia (150), and tinnitus patients without hyposmia (150). The primary outcome of the Neuroscent project is to assess the ability of EEG analysis to distinguish between normosmic and hyposmic participants during olfactory stimulation using the Sniffin' Sticks test.

  22 months

• EEG Parameters (in µV²)

  Alpha Power: Measured in microvolts squared (µV²), representing the magnitude of Alpha wave activity during olfactory stimulation. Theta Power: Measured in microvolts squared (µV²), representing the magnitude of Theta wave activity during olfactory stimulation. We will make use of the Fourier transform as well, which is inherently dimensionless. The data acquisition setup involves placing blindfolded participants in an isolated room and administering three randomized olfactory stimuli (pure olfactory, trigeminal, and olfactory-gustatory) while collecting EEG data. Sessions start and end with a 30-second resting state.

  22 months

• Behavioral/Performance Measures (Scores)

  Olfactory Threshold Scores (as per routinary diagnosis of olfactory performances): Derived from the Sniffin' Sticks test, these scores quantify participants' ability to detect odors, classifying them as normosmic or hyposmic. All the participants will undergo a complete olfactory assessment through the Sniffin' Sticks test. These are represented as numerical scores. The maximum score obtainable in the full Sniffin' Sticks test, which includes the three sub-tests (Threshold, Discrimination, Identification - TDI), is 48. This maximum score is achieved by summing the highest possible score from each of the three components: 16 for olfactory threshold (Threshold), 16 for olfactory discrimination (Discrimination), and 16 for olfactory identification (Identification).

  22 months

• Model Performance Metrics (Accuracy)

  Random Forest Model Classification Accuracy: The accuracy of the classification model used to distinguish between normosmic and hyposmic participants based on EEG data, usually expressed as a percentage or a value between 0 and 1.

  22 months

• Dimensionality Change Outputs (t-SNE)

  t-SNE Features: Although these don't have a specific unit, they represent the reduced dimensional data points used as features in the Random Forest model. These are typically dimensionless and used in the context of visualizing and improving model performance.

  22 months

Secondary Outcomes (7)

• Pure Tone Audiometry Test

  22 months (Simultaneously with the primary outcome)

• Behavioral/Performance Measures (Scores)

  22 months (Simultaneously with the primary outcome)

• EEG Parameters

  22 months (Simultaneously with the primary outcome)

• Model Performance Metrics

  22 months (Simultaneously with the primary outcome)

• Power Analysis and Post-hoc Analyses

  22 months (Simultaneously with the primary outcome)

Other Outcomes (1)

• Predicting Odor Categories in Tinnitus and Non-Tinnitus Groups Using EEG and Machine Learning

  2 months

Study Arms (4)

Normosmic

ACTIVE COMPARATOR

Participants in this group have normal olfactory function, as determined by the Sniffin' Sticks test. They will undergo EEG analysis while being exposed to various olfactory stimuli to establish baseline brain wave patterns for normal olfactory responses. (n=550)

Diagnostic Test: Sniffin'Sticks

Hyposmic

ACTIVE COMPARATOR

Participants in this group have impaired olfactory function (hyposmia), confirmed through the Sniffin' Sticks test. They will undergo EEG analysis during olfactory stimulation to identify differences in brain wave patterns compared to normosmic individuals. (n=150)

Diagnostic Test: Sniffin'Sticks

Tinnitus Patients with Hyposmia

ACTIVE COMPARATOR

This group includes participants who have both tinnitus and hyposmia. They will be subjected to EEG analysis during olfactory testing to investigate the interaction between olfactory and auditory disorders and how these conditions may influence brain wave responses. (n=150)

Diagnostic Test: Sniffin'Sticks

Tinnitus Patients without Hyposmia

ACTIVE COMPARATOR

Participants in this group have tinnitus but normal olfactory function. They will undergo the same EEG and olfactory tests to explore the impact of tinnitus on brain wave patterns in the absence of olfactory disorders and to compare their responses with those of other groups. (n=150)

Diagnostic Test: Sniffin'Sticks

Interventions

Sniffin'Sticks DIAGNOSTIC_TEST

The Sniffin' Sticks test, a validated method to evaluate olfactory functions, utilizes pen-like devices to dispense scents for testing identification, discrimination, and detection of odors. In this study, participants' responses to various scents are recorded. EEG (Electroencephalography) captures electrical activity in the brain during exposure to these odors by using an EEG cap fitted with electrodes on the scalp. This allows for the monitoring of brain wave patterns in response to olfactory stimuli. Both the Sniffin' Sticks test and EEG recordings are conducted simultaneously, providing a dual assessment of behavioral reactions and brain activity to odors. The goal of the study is to compare brain wave patterns and olfactory function in normosmic (normal smell), hyposmic (reduced smell), and tinnitus patients with and without olfactory impairments, delivering comprehensive insights into the neural basis of olfactory perception.

Also known as: EEG

Hyposmic; Normosmic; Tinnitus Patients with Hyposmia; Tinnitus Patients without Hyposmia

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Subjects over 18 years of age who have given consent for the collection of specified data, including medical history and personal information, for the purposes of project implementation and in accordance with the ethical standards of the institutions where the project will be conducted.

You may not qualify if:

• Previous fractures of the facial bones, particularly the ethmoid bone.
• Active tumors of the brain or face, including tumors of the nose, paranasal sinuses, oral cavity, or nasopharynx.
• Active nasal-sinus conditions, particularly radiologically proven sinusitis.
• Mass in the pontocerebellar angle, especially schwannoma of the VIII nerve.
• Patients with acute and chronic inflammatory diseases of the middle ear, otosclerosis, inner ear diseases (especially Meniere's disease), objective tinnitus, and tinnitus caused by middle ear pathologies and CPA tumors.
• Neurodegenerative diseases (especially Alzheimer's and Parkinson's disease).
• Known history of neuropsychiatric or cerebral disorders.
• Use of psychotropic drugs or drugs active on the central nervous system.
• Alcohol and drug abuse.

Sponsors & Collaborators

• Fondazione Policlinico Universitario Agostino Gemelli IRCCS: lead

MeSH Terms

Conditions

Olfaction Disorders; Tinnitus

Interventions

Electroencephalography

Condition Hierarchy (Ancestors)

Sensation Disorders; Neurologic Manifestations; Nervous System Diseases; Signs and Symptoms; Pathological Conditions, Signs and Symptoms; Hearing Disorders; Ear Diseases; Otorhinolaryngologic Diseases

Intervention Hierarchy (Ancestors)

Diagnostic Techniques, Neurological; Diagnostic Techniques and Procedures; Diagnosis; Electrodiagnosis

Study Officials

• Giulio Cesare Passali, Prof

  Fondazione Policlinico Universitario A. Gemelli, IRCCS

  STUDY DIRECTOR

Central Study Contacts

Giuseppe Maulucci, Prof

CONTACT

+390630154265; giuseppe.maulucci@unicatt.it

Giulio Cesare Passali, Prof

CONTACT

3331727194; giuliocesarepassali@policlinicogemelli.it

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NON RANDOMIZED
• Masking: NONE
• Purpose: DIAGNOSTIC
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: This study involves multiple groups of participants who will undergo EEG analysis during olfactory stimulation to assess brain wave responses. The groups include normosmics, hyposmics, tinnitus patients with hyposmia, and tinnitus patients without hyposmia. The study aims to differentiate between these groups and investigate the relationship between olfactory disorders and also highlight the olfactory features of patients with tinnitus. Each group will receive the same olfactory tests and EEG recordings, but they will be compared against each other to understand the different responses and interactions.

Study Record Dates

• First Submitted: August 2, 2024
• First Posted: September 19, 2024
• Study Start: August 31, 2024
• Primary Completion (Estimated): June 30, 2026
• Study Completion (Estimated): August 31, 2026
• Last Updated: September 19, 2024

Record last verified: 2024-07

Data Sharing

• IPD Sharing: Will not share