Brief Title
Transcranial Duplex Scanning and Single Photon Emission Computer Tomography (SPECT) in Parkinsonian Syndromes
Official Title
Diagnostic Value Transcranial Duplex Scanning and Single Photon Emission Tomography in Patients Suspected of Having Idiopathic Parkinson Disease or Atypical Parkinson Syndromes
Brief Summary
The purpose of the study is to determine the sensitivity and specificity of transcranial
duplex scanning (TCD) and single photon emission computer tomography (SPECT) in patients
suspected of having Idiopathic Parkinson Disease (PD) or Atypical Parkinson Syndromes (APS)
with as golden standard the clinical diagnosis after 2-year follow-up.
Detailed Description
PD is a progressive neurodegenerative illness that affects about 50.000 people in the
Netherlands. Diagnosis is based on clinical criteria. However, purely on clinical grounds,
especially in the early stage, it is not possible to differentiate PD from other parkinsonian
syndromes like multiple system atrophy, Progressive Supranuclear Palsy, vascular
parkinsonism, drug induced parkinsonism and essential tremor. Accurate differentiation is
important because treatment and prognosis varies between the different syndromes.
At present SPECT scans are used mostly. However the SPECT is only used in the minority of the
patients suspected of PD mainly because the costs and the discussion about their sensitivity
and specificity to diagnose PD. We are currently finishing a meta-analysis on the diagnostic
value of the SPECT in patients with parkinsonian diseases.
Recently an alternative method to visualise the alterations in the cerebral dopaminergic
pathways of PD patients has been proposed: TCD of the substantia nigra in the brainstem. This
technique has high inter-observer reliability. Becker discovered in 1994 that patients with
PD had bilateral hyperechogenicity of the substantia nigra. Neuropathological studies confirm
the increased echogenicity is because of iron deposition. However the reason of the increased
level of iron is unknown.
Several publications confirm the observation that up to 90% of PD patients have increased
echogenicity of the substantia nigra. In healthy subjects and in patients with essential
tremor this hyperintensity of the substantia nigra is only found in 10%. However 60% of the
healthy subjects with increased echogenicity also have decreased nigra-striatal function on
(18)-F-dopa-PET. So TCD might possibly be an early (presymptomatic) marker for PD.
If substantia nigra scanning is combined with scanning of the nucleus lentiformis, the
differentiation between PD and APS is increased. Another advantage is that with the same
technique the raphe nuclei can be made visible. Several studies confirm the echogenicity of
raphe nuclei is decreased in PD patients with a depression.
Our own experience suggests that the positive predictive value of this technique nears that
of SPECT scans. In our pilot study with 45 patients with PD or APS who underwent SPECT and
TCS we found a positive prediction value of 95%. This would predict that, if TCE is
compatible with PD, a SPECT does not provide additional information; so in theory one might
reduce the amount of SPECT's in almost 50% of cases.
A direct compare of the diagnostic accuracy as to PD between duplex and SPECT scans has until
now not been made. Our hypothesis is that the TCD of substantia nigra duplex scanning is an
accurate diagnostic tool and deserves a place in the diagnostic work-up of PD/Parkinsonism
patients and diagnostically efficient enough to replace 50% of SPECT scans. In comparison
with SPECT duplex scanning is less costly (respectively 80 euro and 400 euro for each SPECT)
and more comfortable for the patient.
Methods:
Subjects:
250 consecutive patients with new parkinsonian complaints in the out-patient clinic of our
university hospital (Maastricht) and a local hospital.
Study design:
The investigator will give a clinical diagnosis at the first visit. All subjects undergo
SPECT and duplex scanning, both tests will be judged blindly for the clinical diagnosis.
After two years follow-up, all patients will be seen by the investigator and again a clinical
diagnosis will be made (investigator is blinded for the results of the duplex and SPECT). At
the end of the follow-up the sensitivity and specificity of the first clinical judgement,
duplex and SPECT can be calculated. The golden standard is the clinical diagnosis at the end
of the follow-up.
Study Type
Observational
Primary Outcome
Concordance of hyperechogenic SN with clinical diagnosis of Parkinson's
Condition
Parkinson's Disease
Publications
* Includes publications given by the data provider as well as publications identified by National Clinical Trials Identifier (NCT ID) in Medline.
Recruitment Information
Estimated Enrollment
196
Start Date
September 1, 2006
Completion Date
September 15, 2012
Primary Completion Date
September 18, 2008
Eligibility Criteria
Inclusion Criteria:
- Patients with unclear parkinsonism at the outpatient clinic
Exclusion Criteria:
- Known diagnosis at presentation
- Life expectation of less than two years because of a non neurological disease
Gender
All
Ages
18 Years - N/A
Accepts Healthy Volunteers
No
Contacts
Wim EJ Weber, MD PhD, ,
Location Countries
Netherlands
Location Countries
Netherlands
Administrative Informations
NCT ID
NCT00368199
Organization ID
1-Vlaar
Responsible Party
Principal Investigator
Study Sponsor
Maastricht University Medical Center
Collaborators
Funding: Stichting Internationaal Parkinson Fonds, The Netherlands
Study Sponsor
Wim EJ Weber, MD PhD, Principal Investigator, Maastricht University Medical Center
Verification Date
February 2018