NCT02632279

Brief Summary

The purpose of this study is to assess the effect of tryptophan depletion on mood and behavior in Parkinson's disease (PD) patients treated with deep brain stimulation (DBS) of the subthalamic nucleus (STN). By doing this, the investigators hope to be able to identify risk factors for and mechanisms underlying psychiatric side effects of STN DBS. The study will be an intervention study with a placebo controlled, randomized cross-over design.

Trial Health

57
Monitor

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
7

participants targeted

Target at below P25 for not_applicable

Timeline
Completed

Started Nov 2015

Typical duration for not_applicable

Geographic Reach
1 country

1 active site

Status
terminated

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

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Study Timeline

Key milestones and dates

Study Start

First participant enrolled

November 1, 2015

Completed
25 days until next milestone

First Submitted

Initial submission to the registry

November 26, 2015

Completed
20 days until next milestone

First Posted

Study publicly available on registry

December 16, 2015

Completed
1.9 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

November 1, 2017

Completed
14 days until next milestone

Study Completion

Last participant's last visit for all outcomes

November 15, 2017

Completed
Last Updated

August 22, 2018

Status Verified

August 1, 2018

Enrollment Period

2 years

First QC Date

November 26, 2015

Last Update Submit

August 20, 2018

Conditions

Parkinson's Disease

Keywords

Parkinson's diseaseDeep Brain StimulationSubthalamic nucleusTryptophan depletionSerotonin

Outcome Measures

Primary Outcomes (1)

  • Mood

    as assessed through the Profile of Mood States

    There will be 6 measurements spread over 2 testing days with a wash-out period of min. 1 weak. baseline measure, 3.5 hours after intake of the amino acid mixture, and 5.5 hours after intake of the amino acid mixture

Secondary Outcomes (3)

  • Motor scores

    There will be 6 measurements spread over 2 testing days with a wash-out period of min. 1 weak. baseline measure, 3.5 hours after intake of the amino-acid mixture, and 5.5 hours after intake of the amino-acid mixture

  • Impulsivity

    There will be 6 measurements spread over 2 testing days with a wash-out period of min. 1 weak. baseline measure, 3.5 hours after intake of the amino-acid mixture, and 5.5 hours after intake of the amino-acid mixture

  • Emotional Responsiveness

    There will be 4 measurements spread over 2 testing days with a wash-out period of min. 1 weak. baseline measure, 3.5 hours after intake of the amino-acid mixture

Study Arms (2)

TRP depleted

EXPERIMENTAL

TRP depleted protein drink

Dietary Supplement: Tryptophan (TRP) depletionDevice: Stimulator ONDevice: Stimulator OFF

Placebo

PLACEBO COMPARATOR

Balanced protein drink (+1.21g of TRP)

Dietary Supplement: PlaceboDevice: Stimulator ONDevice: Stimulator OFF

Interventions

Tryptophan (TRP) depletionDIETARY_SUPPLEMENT

TRP depletion will be accomplished by administering a TRP-low amino acid protein drink containing 100 g of gelatin powder. The protein mixture consists of 18 amino acids. According to Dutch law, TRP is considered a food supplement and is not registered as a medicine.

Also known as: TRP depleted
TRP depleted
PlaceboDIETARY_SUPPLEMENT

The placebo treatment will consist of an identical amino acid protein drink containing 100 g of gelatin powder to which 1.21g TRP is added.

Placebo
Stimulator ONDEVICE

Participants will be tested while their stimulator is turned ON

PlaceboTRP depleted
Stimulator OFFDEVICE

Participans will be tested while their stimulator is turned OFF

PlaceboTRP depleted

Eligibility Criteria

Sexall
Healthy VolunteersNo
Age GroupsChild (0-17), Adult (18-64), Older Adult (65+)

You may qualify if:

  • subjects must be mentally competent
  • subjects must have undergone STN DBS surgery for PD symptomatology

You may not qualify if:

  • head injury
  • stroke
  • currentl malignancy or infection
  • neurological disorders other than PD
  • psychoactive medication: specifically antidepressants and antipsychotics ( a stable dose of benzodiazepines will be allowed)
  • clinically relevant cognitive decline, operationalized as a MMSE score \< 24
  • current psychiatric syptomatology, operationalized as a Hamilton Depression scale score \> 16 or a score \>2 on one of the MDS-UPDRS section I, items 1-6

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

Maastricht University Medical Center

Maastricht, Limburg, Netherlands

Location

MeSH Terms

Conditions

Parkinson Disease

Interventions

Tryptophantryptophyltryptophan

Condition Hierarchy (Ancestors)

Parkinsonian DisordersBasal Ganglia DiseasesBrain DiseasesCentral Nervous System DiseasesNervous System DiseasesMovement DisordersSynucleinopathiesNeurodegenerative Diseases

Intervention Hierarchy (Ancestors)

Amino Acids, AromaticAmino Acids, CyclicAmino AcidsAmino Acids, Peptides, and ProteinsAmino Acids, Essential

Study Officials

  • Yasin Temel, MD, PhD

    Maastricht University Medical Center

    PRINCIPAL INVESTIGATOR

Study Design

Study Type
interventional
Phase
not applicable
Allocation
RANDOMIZED
Masking
TRIPLE
Who Masked
PARTICIPANT, INVESTIGATOR, OUTCOMES ASSESSOR
Purpose
TREATMENT
Intervention Model
CROSSOVER
Sponsor Type
OTHER
Responsible Party
SPONSOR

Study Record Dates

First Submitted

November 26, 2015

First Posted

December 16, 2015

Study Start

November 1, 2015

Primary Completion

November 1, 2017

Study Completion

November 15, 2017

Last Updated

August 22, 2018

Record last verified: 2018-08

Locations

NL(1)