The Neurobiology of Two Distinct Types of Progressive Apraxia of Speech (SLD4T)

April 27, 2026 updated by: Keith A. Josephs, Mayo Clinic
The purpose of this study is to identify and distinguish two different types of Progressive Apraxia of Speech through clinical imaging and testing.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Apraxia of speech (AOS) is a motor speech disorder reflecting a problem with the programming and/or planning of speech. AOS is well recognized in the context of stroke where onset is acute and the condition improves or is stable and chronic. AOS that is insidious in onset and progresses over time because of neurodegeneration is less well recognized and understood. For the past decade the investigators have been studying patients with primary progressive apraxia of speech (PAOS). They have demonstrated that it can be the earliest manifestation of an underlying neurodegenerative disease and have recently reported that the profile of PAOS characteristics can differ among affected patients. In some instances, the speech pattern is dominated by distorted sound substitutions and additions, and other features attributable to articulatory difficulty, while in other instances the pattern is dominated by slow, prosodically segmented speech. We have designated the first profile as Phonetic PAOS (Ph-PAOS) and the second as Prosodic PAOS (Pr-PAOS; previously referred to in our studies as type 1 and 2, respectively). Importantly, it appears that the AOS pattern type may have prognostic implications. In a recent longitudinal study, the investigators observed that in some PAOS patients, the AOS remained the most salient feature over an average of seven years of the neurodegenerative disease. Other patients developed a severe extrapyramidal syndrome, resembling progressive supranuclear palsy, within five years, causing significant morbidity, including the inability to ambulate and a shortened life span; interestingly, this more aggressive course was associated with the Pr- PAOS type. At present, little is known about these types. To address the main aim to better understand the neurobiology and clinical associations of PAOS types, they will perform longitudinal speech, language, and neurocognitive testing, acoustic analyses, neuroimaging, and autopsy in a cohort of 47 new PAOS patients (for 80 PAOS patients total) and healthy controls.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Observational

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
47

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • United States
    • Minnesota
      • Rochester, Minnesota, United States, 55905
        • Recruiting
        • Mayo Clinic
        • Contact:
        • Principal Investigator:
          • Keith A Josephs, MD

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

Patients that have been diagnosed as having Progressive Apraxia of Speech.

Description

Inclusion Criteria:

  1. All enrolled patients must be over the age of 18, speak English as their primary language, and have an informant who can provide an independent evaluation of functioning.
  2. Each new patient must present with a chief complaint of progressive impairment of speech and must have evidence of AOS documented by a speech-language pathologist during routine clinical evaluation.
  3. At study entry, all patients must have speech sufficiently intelligible for a confident diagnosis of AOS, dysarthria, and/or aphasia, and for acoustic analysis.

Exclusion Criteria:

  1. Any patient whose speech is not intelligible enough for confident speech-language diagnosis will be excluded from the study.
  2. All patients with concurrent illnesses that could account for speech deficits (e.g., traumatic brain injury, strokes, developmental syndromes), and patients meeting criteria for another neurodegenerative disease (e.g., Alzheimer's type dementia57), will be excluded.
  3. Patients with aphasia or dysarthria who do not have PAOS, or whose aphasia or dysarthria at study entry is more severe than PAOS, will be excluded.
  4. All women who are pregnant, or post-partum and breast-feeding, will be excluded as they are unable to undergo the required imaging. All women who can become pregnant must have a pregnancy test no more than 48 hours before the DaTscan.
  5. Patients will also be excluded if MRI is contraindicated (e.g., metal in head, cardiac pace maker), if there is severe claustrophobia, if there are conditions that may confound brain imaging studies (e.g. structural abnormalities, including subdural hematoma or intracranial neoplasm), or if they are medically unstable or are on medications that might affect brain structure or metabolism (e.g. chemotherapy).
  6. Patients will be excluded if they do not have an informant, or do not consent to the research.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Observational Models: Cohort
  • Time Perspectives: Prospective

Cohorts and Interventions

Group / Cohort

Group / Cohort

A group or subgroup of participants in an observational study that is assessed for biomedical or health outcomes.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Progressive Apraxia of Speech
Diagnostic test: Testing protocol for the study
All patients will see a Neurologist for a neuro exam and consult, see a Speech Pathologist for assessment of speech and language skills, see the Study Coordinator for neuropsych testing (brief tests of thinking, memory, visual spatial skills, etc), undergo an MRI of the brain and a DaTscan of the brain.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Distinguish types of Progressive Apraxia of Speech
Time Frame: 1-2 years after baseline imaging
Distinguish types of PAOS using the Apraxia of Speech Rating Scale (ASRS)
1-2 years after baseline imaging

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Mayo Clinic

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Keith Josephs, MD, Mayo Clinic

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Helpful Links

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
August 1, 2017

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
July 1, 2027

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
July 1, 2027

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
October 11, 2017

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
October 16, 2017

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
October 18, 2017

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
May 1, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
April 27, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
April 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 17-002468

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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