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Cerebrospinal fluid and blood flow in mild cognitive impairment and Alzheimer's disease: a differential diagnosis from idiopathic normal pressure hydrocephalus.

El Sankari S, Gondry-Jouet C, Fichten A, Godefroy O, Serot JM, Deramond H, Meyer ME, Balédent O - Fluids Barriers CNS (2011)

Bottom Line: The patients' results were compared with those obtained for HEVs (n = 12), and for NPH patients (n = 13), using multivariate analysis.Arterial tCBF and the calculated pulsatility index were significantly greater in a-MCI patients than in HEVs.Our preliminary data show that a-MCI patients present with high systolic arterial peak flows, which are associated with higher mean total cerebral arterial flows.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Image Processing, Jules Verne University of Picardy and Amiens University Hospital, CHU d'Amiens, F-80054 Amiens cedex, France. olivier.baledent@chu-amiens.fr.

ABSTRACT

Background: Phase-contrast magnetic resonance imaging (PC-MRI) enables quantification of cerebrospinal fluid (CSF) flow and total cerebral blood (tCBF) flow and may be of value for the etiological diagnosis of neurodegenerative diseases. This investigation aimed to study CSF flow and intracerebral vascular flow in patients with Alzheimer's disease (AD) and patients with amnesic mild cognitive impairment (a-MCI) and to compare the results with patients with idiopathic normal pressure hydrocephalus (NPH) and with healthy elderly volunteers (HEV).

Methods: Ten a-MCI and 9 mild AD patients were identified in a comprehensive neurological and neuropsychological assessment. They underwent brain MRI; PC-MRI pulse sequence was performed with the following parameters: two views per segment; flip angle: 25° for vascular flow and 20° for CSF flow; field-of-view (FOV): 14 × 14 mm²; matrix: 256 × 128; slice thickness: 5 mm; with one excitation for exams on the 3 T machine, and 2 excitations for the 1.5 T machine exams. Velocity (encoding) sensitization was set to 80 cm/s for the vessels at the cervical level, 10 or 20 cm/s for the aqueduct and 5 cm/s for the cervical subarachnoid space (SAS). Dynamic flow images were analyzed with in-house processing software. The patients' results were compared with those obtained for HEVs (n = 12), and for NPH patients (n = 13), using multivariate analysis.

Results: Arterial tCBF and the calculated pulsatility index were significantly greater in a-MCI patients than in HEVs. In contrast, vascular parameters were lower in NPH patients. Cervical CSF flow analysis yielded similar values for all four populations. Aqueductal CSF stroke volumes (in μl per cardiac cycle) were similar in HEVs (34 ± 17) and AD patients (39 ± 18). In contrast, the aqueductal CSF was hyperdynamic in a-MCI patients (73 ± 33) and even more so in NPH patients (167 ± 89).

Conclusion: Our preliminary data show that a-MCI patients present with high systolic arterial peak flows, which are associated with higher mean total cerebral arterial flows. Aqueductal CSF oscillations are within normal range in AD and higher than normal in NPH. This study provides an original dynamic vision of cerebral neurodegenerative diseases, consistent with the vascular theory for AD, and supporting primary flow disturbances different from those observed in NPH.

No MeSH data available.


Related in: MedlinePlus

Vascular arterial, venous and arteriovenous flow curves . Mean arterial, venous and arteriovenous flows are represented over two successive cardiac cycles (CC) in one patient. The arterial blood flow peaks and troughs are represented. The difference in amplitude (ΔF = Fmax - Fmin) and latency ((ΔT = Tmin - Tmax) between these 2 features is also shown. The arterial pulsatility index (defined as ΔF/ΔT) corresponds to the slope of the arterial flow curve at the beginning of systole. The arterial pulse volume (defined as ΔF × ΔT/2) corresponds to the systolic arterial inflow volume. The arteriovenous flow curve results from the difference between the arterial and the venous flow curves over a given CC. Integration of the area under the curve yields the arteriovenous stroke volume, which represents the volume blood carried into the cranium (the input cerebral blood volume) or expulsed caudally (the output cerebral blood volume) from the cranium over the course of the CC. The difference in latency between the arterial and venous flow peaks (in milliseconds or as a percentage of the CC) corresponds to the arteriovenous delay (AVD).
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Figure 2: Vascular arterial, venous and arteriovenous flow curves . Mean arterial, venous and arteriovenous flows are represented over two successive cardiac cycles (CC) in one patient. The arterial blood flow peaks and troughs are represented. The difference in amplitude (ΔF = Fmax - Fmin) and latency ((ΔT = Tmin - Tmax) between these 2 features is also shown. The arterial pulsatility index (defined as ΔF/ΔT) corresponds to the slope of the arterial flow curve at the beginning of systole. The arterial pulse volume (defined as ΔF × ΔT/2) corresponds to the systolic arterial inflow volume. The arteriovenous flow curve results from the difference between the arterial and the venous flow curves over a given CC. Integration of the area under the curve yields the arteriovenous stroke volume, which represents the volume blood carried into the cranium (the input cerebral blood volume) or expulsed caudally (the output cerebral blood volume) from the cranium over the course of the CC. The difference in latency between the arterial and venous flow peaks (in milliseconds or as a percentage of the CC) corresponds to the arteriovenous delay (AVD).

Mentions: Data were analyzed using in-house image processing software http://www.tidam.fr. An optimized CSF and blood flow segmentation algorithm was used to automatically extract the region of interest (ROI) at each level. The ROIs (Figure 1) considered here were the right and left internal carotid arteries (ICAs), vertebral arteries (VAs), internal jugular veins (IJVs) and epidural veins (EVs) (for blood flows) and the aqueductal and cervical (C2-C3) areas (for CSF flows). In each ROI, flows were calculated for each of the 32 time frames in order to build a flow curve over the course of the CC. Flows in the ICA and VA on the left and right sides were summed to generate the total arterial cerebral blood flow (tCBF). We also calculated an arterial pulsatility index (API), which corresponded to the slope of the flow curve over time. We first measured the maximum and minimum flow amplitudes (Fmax and Fmin, respectively, expressed in ml/min) and their times of occurrence (Tmax and Tmin, respectively, expressed in milliseconds). The API index was then calculated as follows: API = (Fmax - Fmin)/(Tmin - Tmax)/2, and is represented in Figure 2.


Cerebrospinal fluid and blood flow in mild cognitive impairment and Alzheimer's disease: a differential diagnosis from idiopathic normal pressure hydrocephalus.

El Sankari S, Gondry-Jouet C, Fichten A, Godefroy O, Serot JM, Deramond H, Meyer ME, Balédent O - Fluids Barriers CNS (2011)

Vascular arterial, venous and arteriovenous flow curves . Mean arterial, venous and arteriovenous flows are represented over two successive cardiac cycles (CC) in one patient. The arterial blood flow peaks and troughs are represented. The difference in amplitude (ΔF = Fmax - Fmin) and latency ((ΔT = Tmin - Tmax) between these 2 features is also shown. The arterial pulsatility index (defined as ΔF/ΔT) corresponds to the slope of the arterial flow curve at the beginning of systole. The arterial pulse volume (defined as ΔF × ΔT/2) corresponds to the systolic arterial inflow volume. The arteriovenous flow curve results from the difference between the arterial and the venous flow curves over a given CC. Integration of the area under the curve yields the arteriovenous stroke volume, which represents the volume blood carried into the cranium (the input cerebral blood volume) or expulsed caudally (the output cerebral blood volume) from the cranium over the course of the CC. The difference in latency between the arterial and venous flow peaks (in milliseconds or as a percentage of the CC) corresponds to the arteriovenous delay (AVD).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3045982&req=5

Figure 2: Vascular arterial, venous and arteriovenous flow curves . Mean arterial, venous and arteriovenous flows are represented over two successive cardiac cycles (CC) in one patient. The arterial blood flow peaks and troughs are represented. The difference in amplitude (ΔF = Fmax - Fmin) and latency ((ΔT = Tmin - Tmax) between these 2 features is also shown. The arterial pulsatility index (defined as ΔF/ΔT) corresponds to the slope of the arterial flow curve at the beginning of systole. The arterial pulse volume (defined as ΔF × ΔT/2) corresponds to the systolic arterial inflow volume. The arteriovenous flow curve results from the difference between the arterial and the venous flow curves over a given CC. Integration of the area under the curve yields the arteriovenous stroke volume, which represents the volume blood carried into the cranium (the input cerebral blood volume) or expulsed caudally (the output cerebral blood volume) from the cranium over the course of the CC. The difference in latency between the arterial and venous flow peaks (in milliseconds or as a percentage of the CC) corresponds to the arteriovenous delay (AVD).
Mentions: Data were analyzed using in-house image processing software http://www.tidam.fr. An optimized CSF and blood flow segmentation algorithm was used to automatically extract the region of interest (ROI) at each level. The ROIs (Figure 1) considered here were the right and left internal carotid arteries (ICAs), vertebral arteries (VAs), internal jugular veins (IJVs) and epidural veins (EVs) (for blood flows) and the aqueductal and cervical (C2-C3) areas (for CSF flows). In each ROI, flows were calculated for each of the 32 time frames in order to build a flow curve over the course of the CC. Flows in the ICA and VA on the left and right sides were summed to generate the total arterial cerebral blood flow (tCBF). We also calculated an arterial pulsatility index (API), which corresponded to the slope of the flow curve over time. We first measured the maximum and minimum flow amplitudes (Fmax and Fmin, respectively, expressed in ml/min) and their times of occurrence (Tmax and Tmin, respectively, expressed in milliseconds). The API index was then calculated as follows: API = (Fmax - Fmin)/(Tmin - Tmax)/2, and is represented in Figure 2.

Bottom Line: The patients' results were compared with those obtained for HEVs (n = 12), and for NPH patients (n = 13), using multivariate analysis.Arterial tCBF and the calculated pulsatility index were significantly greater in a-MCI patients than in HEVs.Our preliminary data show that a-MCI patients present with high systolic arterial peak flows, which are associated with higher mean total cerebral arterial flows.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Image Processing, Jules Verne University of Picardy and Amiens University Hospital, CHU d'Amiens, F-80054 Amiens cedex, France. olivier.baledent@chu-amiens.fr.

ABSTRACT

Background: Phase-contrast magnetic resonance imaging (PC-MRI) enables quantification of cerebrospinal fluid (CSF) flow and total cerebral blood (tCBF) flow and may be of value for the etiological diagnosis of neurodegenerative diseases. This investigation aimed to study CSF flow and intracerebral vascular flow in patients with Alzheimer's disease (AD) and patients with amnesic mild cognitive impairment (a-MCI) and to compare the results with patients with idiopathic normal pressure hydrocephalus (NPH) and with healthy elderly volunteers (HEV).

Methods: Ten a-MCI and 9 mild AD patients were identified in a comprehensive neurological and neuropsychological assessment. They underwent brain MRI; PC-MRI pulse sequence was performed with the following parameters: two views per segment; flip angle: 25° for vascular flow and 20° for CSF flow; field-of-view (FOV): 14 × 14 mm²; matrix: 256 × 128; slice thickness: 5 mm; with one excitation for exams on the 3 T machine, and 2 excitations for the 1.5 T machine exams. Velocity (encoding) sensitization was set to 80 cm/s for the vessels at the cervical level, 10 or 20 cm/s for the aqueduct and 5 cm/s for the cervical subarachnoid space (SAS). Dynamic flow images were analyzed with in-house processing software. The patients' results were compared with those obtained for HEVs (n = 12), and for NPH patients (n = 13), using multivariate analysis.

Results: Arterial tCBF and the calculated pulsatility index were significantly greater in a-MCI patients than in HEVs. In contrast, vascular parameters were lower in NPH patients. Cervical CSF flow analysis yielded similar values for all four populations. Aqueductal CSF stroke volumes (in μl per cardiac cycle) were similar in HEVs (34 ± 17) and AD patients (39 ± 18). In contrast, the aqueductal CSF was hyperdynamic in a-MCI patients (73 ± 33) and even more so in NPH patients (167 ± 89).

Conclusion: Our preliminary data show that a-MCI patients present with high systolic arterial peak flows, which are associated with higher mean total cerebral arterial flows. Aqueductal CSF oscillations are within normal range in AD and higher than normal in NPH. This study provides an original dynamic vision of cerebral neurodegenerative diseases, consistent with the vascular theory for AD, and supporting primary flow disturbances different from those observed in NPH.

No MeSH data available.


Related in: MedlinePlus