Orexin and Tau Pathology in Cognitively Normal Elderly

Orexin and Tau Pathology in Cognitively Normal Elderly (A New Prevention Strategy for Alzheimer's Disease)

Alzheimer's disease (AD) is a common neurodegenerative disease characterized by the accumulation of amyloid plaques and neurofibrillary tangles. Current consensus is that the AD pathological process begins decades before clinical symptoms occur. This long "preclinical" phase of AD might first become detectable in middle-age as deposits of hyperphosphorylated tau (P-tau) in the transentorhinal cortex and subcortical nuclei such as the locus coeruleus (LC) and the nucleus basalis of Meynert. There is strong preliminary evidence showing that cerebrospinal fluid (CSF) levels of orexin-A (OxA) are associated with increased P-tau (r=.52, p<.01) and total-tau (T-tau) (r=.42, p<.01) in cognitively normal older adults (mean age: 69.6±8.6 years).

This study poses that onset of tauopathy in the LC results in down regulation of orexin receptors, leading to a homeostatic increase of OxA production by the hypothalamus, which results in changes in core body temperature (CBT) and sleep disruption that cause further neurodegeneration. This hypothesis will be tested by demonstrating that increases in CSF P-tau are associated in vivo with tau PET uptake, and that tau binding in the LC is associated with increases in CSF OxA (Aim 1); and second, by analyzing the downstream consequences of increased central nervous system (CNS) OxA on sleep architecture and CBT (Aim 2). To test these hypotheses, 19 older adults (age 55-75) balanced by sex, will first perform a full clinical evaluation and PET-MRI where Tau burden will be analyzed by PET-MR using 18F-MK6240 (visits 1-2). Subjects will later undergo 7 days of actigraphy followed by nocturnal polysomnography (NPSG) for 2 consecutive nights (N1-2) during which we will measure CBT (visits 3-4). A morning lumbar puncture (LP) will be performed after N2 to obtain CSF.

Study Overview

• Status: Completed
• Conditions: Alzheimer Disease; Elderly
• Intervention / Treatment: Procedure: Actigraphy; Procedure: Nocturnal Polysomnograpahy (NPSG)

Detailed Description

There is the potential to identify: 1) an association between CSF P-tau and in vivo 18F-MK6240 uptake; 2) a mechanism by which tau pathology may contribute to orexin dysfunction; 3) evidence that orexin dysfunction disrupts sleep and CBT rhythm; and, 4) CNS orexin dysfunction as a new therapeutic target for AD prevention.

• Study Type: Interventional
• Enrollment (Actual): 25
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • New York
    • New York, New York, United States, 10016
      • New York University School of Medicine

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 55 years to 75 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Male and female subjects with normal cognition and 55-75 years of age will be enrolled.
• Subjects will be within normal limits on neurological and psychiatric examinations. All subjects enrolled will have both a Clinical Dementia Rating (CDR)=0 and a MMSE≥27
• All subjects will have had a minimum of 12 years of education. Among minority subjects >80% of the elderly individuals coming to the NYU-ADC meet this criterion. (The education restriction reduces performance variance on cognitive test measures and improves the sensitivity for detecting pathology and disease progression using the robust norms available at NYU. Given the majority of subjects will meet this criterion we do not consider this a major selection bias or generalization limitation for this study).
• An informed family member or life-partner (preferably bed-partner) will be interviewed over the phone or on the first or second visit to confirm the reliability of the subject interview.

Exclusion Criteria:

• History of brain tumor, MRI evidence of brain damage or brain disease including significant trauma, hydrocephalus, seizures, mental retardation or other serious neurological disorder (e.g. Parkinson's disease or other movement disorders). Subjects with a Fazekas scale >2 will be excluded109.
• Significant history of alcoholism or drug abuse.
• History of psychiatric illness (e.g., schizophrenia, bipolar, PTSD, or life-long history of major depression).
• Geriatric Depression Scale (short form)>5.
• Insulin dependent diabetes.
• Evidence of clinically relevant cardiac, pulmonary, endocrine or hematological conditions (e.g. low platelet levels).
• Physical impairment of such severity as to adversely affect the validity of psychological testing.
• Any prosthetic devices (e.g., pacemaker or surgical clips) that constitutes a hazard for MRI imaging or CBT measurements.
• History of a first-degree family member with early onset (age <60 years) dementia.
• Irregular sleep-wake rhythms (based on the actigraphy recordings) or significant OSA (AHI4%≥15).
• Medications affecting cognition or sleep.
• Presence of any known or suspected obstructive disease of the gastrointestinal tract, including but not limited to diverticulitis and inflammatory bowel disease.
• History of disorders or impairment of the gag reflex.
• Previous gastrointestinal surgery.
• Previous felinization of the esophagus.
• Subjects who might undergo Nuclear Magnetic Resonance (NMR) or MRI scanning during the period that the CorTemp® Disposable Temperature Sensor is within the body.
• Subjects hypomotility disorders of the gastrointestinal tract including but not limited to Ileus.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Elderly Patients	Procedure: Actigraphy; Recording of sleep/wake cycle and TST by actigraphy to be completed at home by subject over 7 days; Procedure: Nocturnal Polysomnograpahy (NPSG); N1 habituation and N2 data collection

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Cerebral Spinal Fluid (CSF) P-Tau measured with PET-MR	CSF P-tau is associated with cortical tau uptake	4 Weeks
18MK6240 binding amount measured with PET-MR	Tau binding in the brainstem is associated with increases in CSF OxA. PET-MR using 18MK6240 (PET Radiotracer for Imaging Neurofibrillary), which will be performed 1-4 weeks before the LP (visit 2).	2 weeks

Collaborators and Investigators

• Sponsor: NYU Langone Health
• Collaborators: National Institute on Aging (NIA)
• Investigators: Principal Investigator: Ricardo Osorio, M.D, NYU Langone Health

Publications and helpful links

General Publications

• Blessing EM, Parekh A, Betensky RA, Babb J, Saba N, Debure L, Varga AW, Ayappa I, Rapoport DM, Butler TA, de Leon MJ, Wisniewski T, Lopresti BJ, Osorio RS. Association between lower body temperature and increased tau pathology in cognitively normal older adults. Neurobiol Dis. 2022 Sep;171:105748. doi: 10.1016/j.nbd.2022.105748. Epub 2022 May 10.

Study record dates

Study Major Dates

• Study Start (Actual): March 27, 2018
• Primary Completion (Actual): May 13, 2019
• Study Completion (Actual): May 13, 2019

Study Registration Dates

• First Submitted: February 8, 2017
• First Submitted That Met QC Criteria: February 10, 2017
• First Posted (Actual): February 15, 2017

Study Record Updates

• Last Update Posted (Actual): February 24, 2021
• Last Update Submitted That Met QC Criteria: February 23, 2021
• Last Verified: February 1, 2021

More Information

Terms related to this study

• Keywords: Orexin; Core Body Temperature
• Additional Relevant MeSH Terms: Mental Disorders; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Neurocognitive Disorders; Neurodegenerative Diseases; Dementia; Tauopathies; Alzheimer Disease
• Other Study ID Numbers: 16-01529

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