cerebrovasculaire dysfunctie alzheimer dementia mild cognitive impairment
Conditions
Interventions
None listed
Sponsors
Academisch Ziekenhuis Maastricht
Eligibility
Age
18 Years to 99 Years
Inclusion criteria
Inclusion criteria: Alzheimer patients Alzheimer diagnosed according to the DSM-IV criteria for dementia (American Psychiatric Association, 1994), and NINCDS-ADRDA criteria (McKhann et al., 1984)(probable, possible). Presence of a reliable informant, who has contact with the patient at least once a week. Informed consent of the patient before participation into the study.;MCI patients The descriptions proposed by Petersen et al. (1999) are used to classify MCI. Informed consent of the patient before participation into the study.;Controls Informed consent before participation into the study. Control matching parameters will be age, sex and level of education.
Exclusion criteria
Exclusion criteria: Alzheimer patients If living in a nursing home at the start of the study. Patients without a reliable informant. Diagnosis of Vascular Dementia, according to NINDS/AIREN criteria (Roman et al., 1993) Presence of micro-vascular pathology as defined by the Fazekas scale (Fazekas, 1987) Use of psychopharmacological medication. Abuse of alcohol and/or drugs. Diabetes Heart disease Presence of hypertension will be considered as a co-variate in the analysis.;To exclude patients with a possible stenosis (> 50%) of extra- and/or intracranial vessels a non-invasive and non-aggravating standard duplex investigation will be performed in all subjects. Patients without a temporal *doppler* window will be excluded. In general about 1 out of 10 subjects will have no temporal window. According to this about 22 Alzheimer patients will have to be screened to acquire a group of 20 subjects.;MCI patients If living in a nursing home at the start of the study. Use of psychopharmacological medication. Abuse of alcohol and/or drugs. Diabetes Heart disease Presence of hypertension will be considered as a co-variate.;To exclude patients with a possible stenosis (> 50%) of extra- and/or intracranial vessels a non-invasive and non-aggravating standard duplex investigation will be performed in all subjects. Patients without a temporal *doppler* window will be excluded. In general about 1 out of 10 subjects will have no temporal window. According to this about 22 MCI patients will have to be screened to acquire a group of 20 subjects. Controls Use of psychopharmacological medication. Abuse of alcohol and/or drugs. Diabetes Heart disease;To exclude participants with a possible stenosis (> 50%) of extra- and/or intracranial vessels a non-invasive and non-aggravating standard duplex investigation will be performed in all subjects. Participants without a temporal *doppler* window will be excluded. In general about 1 out of 10 subjects will have no temporal window. According to this about 22 controls will have to be screened to acquire a group of 20 subjects Control matching parameters will be age, sex and level of education. Presence of hypertension will be considered as a co-variate.
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Cerebrovascular recording methods Neurovascular coupling studied with non-invasive Doppler-technique Two 2 MHz-probes are mounted on an individually fitted headband. The P2-segment of the left posterior cerebral artery (PCA) and the right middle cerebral artery (MCA) are insonated. The recording of the MCA flow velocity allows determination for possible non-specific effects in the test situation such as blood pressure changes, which might affect cerebral circulation. Mean blood flow velocities are recorded using a Transcranial Doppler device (DWL, Singen, Germany). As a stimulation parameter a colour movie is used. The visual stimulation protocol consists of 10 cycles each with a resting phase of 20 s (eyes closed) and a stimulating phase of 40 s. Changes between phases are signalled acoustically using a tone. Beat-to-beat intervals of cerebral blood flow velocity are interpolated linearly for an averaging procedure. To assure independence from the insonation angle and to allow comparisons between the different participants, absolute data are transformed into relative changes of cerebral blood flow velocity in relation to baseline. The baseline is calculated from the blood flow velocity averaged for a time span of 10 s before the beginning of the stimulation phase. The method and algorithm for analysing the data sets in terms of a control system are described in detail in Rosengarten (2001). The responses of the ten test sequences are averaged to improve signal-to-noise ration. Cerebral autoregulation The electrocardiogram (ECG) is measured by an in-home made portable ECG-amplifier. Arterial blood pressure (ABP) is measured using a non-invasive finger blood pressure monitor (Portapres, TNO) commonly used in studies on dynamic cerebral autoregulation. The cuff of the right size is placed on the middle finger of the left hand. A DWL Multidop Transcranial Dopplersonography device is used to measure the cerebral blood flow velocity (CBFV) in | — |
Secondary
| Measure | Time frame |
|---|---|
| results of neuropsychological tests performed before participation in this investigation. results of cerebral neuroimaging (CT and/or MRI) performed before participation in this investigation. | — |
Countries
Netherlands
Outcome results
None listed