8/9/2019 Cognitive Biochemical and Imaging Profile Idiopathic Normal Pressure Hydrocephalus

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S32   Abstracts of the Hydrocephalus 2008 Congress / Clinical Neurology and Neurosurgery 110S (2008), S1–S41

O.118   Cognitive and motor improvement after shunting in

normal pressure hydrocephalus: A real change or merely

the learning effect after repeated test?

E. Solana 1 , M.A. Poca 2 , J. Sahuquillo 2 , A. Muns 3 , C. Junqué 1

1 Neurosurgery and Neurotraumatology R esearch Unint, Vall d’Hebron

University Hospital, Barcelona, Spain;  2 Department of Neurosurgery,

 Neurosurgery and Neurotraumatology Research Unint, Vall d’Hebron

University Hospital, Barcelona, Spain; 3

 Department of Psychiatry and Clinical Psychophysiology, University of Barcelona and Institut 

d’Investigations Biomèdiques August Pi-Sunyer, Barcelona, Spain

The test-retest method is commonly used in the management of patients

with normal pressure hydrocephalus (NPH). However, interpretation of 

improved results in subsequent evaluations is controversial, because higher

scores could reflect a real change in cognitive abilities or could be simply

the result of a learning effect.

Objective and Methods:   To determine the effect of testing-retesting in

NPH patients, we analyzed changes in five neuropsychological tests

(Toulouse-Pieron, Trail Making A, Grooved Pegboard, Word Fluency and

Bingley’s Memory tests) and several motor abilities (motor performance

test, length of step and walking speed) in a series of 32 NPH patients

who underwent the same battery on 4 consecutive days. The results were

compared with those obtained in 30 healthy volunteers who underwent the

same procedure.

Results: NPH patients showed no statistically significant differences in any

of the neuropsychological or motor tests performed on 4 consecutive days.

In contrast, healthy volunteers showed statistically significant improvement

in the Toulouse-Pieron, Trail Making A, and Grooved Pegboard tests (P<

0.001) but not in the remaining tests.

Conclusions:   No learning effect was found in NPH patients in any of 

the neuropsychological or motor tests evaluated. Clinical improvement

after retesting in NPH patients reflects real changes and this strategy

can therefore be used both in diagnosis and in the evaluation of surgical

outcomes.

Supported by Grant FIS:PI07/0681 to M.A. Poca.

O.119   What enhanced cortical activity occurs in the INPH

brain after CSF drainage in conjunction with improved

performance?

N. Lenfeldt 1 , A. Larsson 2 , L. Nyberg 3 , M. Andersson 1, J. Malm 1

1Clinical Neuroscience, Umeå, Sweden;  2 Radiation Sciences, Umeå,

Sweden;  3 Integrative Medical Biology, Umeå, Sweden

Objective:   This study used functional MRI (fMRI) to investigate the

changes in cortical activity that accompanies improved motor and cognitive

performance after long-term external lumbar drainage (ELD) of CSF in

patients with INPH.

Methods:  Eighteen INPH patients and ten matched controls were included

in the study, and data from eleven INPH patients were analysed both before

and after the ELD. Their average drain volume was 400 ml/3d. Brain

activation was investigated using fMRI protocols taxing motor performance

(finger tapping and reaction time) and cognitive functioning (memory andattention) before and after ELD. Behavioural data were compared at a

significance level of 0.05, whereas functional MRI data were analysed by

statistical parametric mapping including a conjunction analysis of areas

enhancing in activity after ELD and areas activated in controls (p< 0.005,

uncorrected).

Results: Right-hand finger tapping improved from 104 to 117 (p= 0.02).

Left-hand finger tapping showed a tendency to improve (p= 0.12). Right-

hand reaction time improved from 1630 ms to 1409 ms and left-hand

reaction time from 1760 ms to 1467 (both p-values = 0.01). Significant

improvements in motor performance were accompanied by bilateral in-

creased activation in the supplementary motor area. Cognitive functions

did also improve, but not significantly so, and hence the cortical cognitive

enhancement areas could not be determined.

Conclusions:   The results suggest that motor function recovery in INPH

patients after CSF removal is related to enhanced activity in medial parts

of frontal motor areas considered crucial for motor planning. Regarding

cognitive functioning, longer recuperation times seems to be needed before

significant effects arise.

O.120   Cognitive and biochemical profile of patients suffering

from idiopathic normal pressure hydrocephalus

A. Tarnaris 1, M.D. Chapman 3 , E. Pullen 2 , A. Toma 1, A. Petzold 3 ,

N.D. Kitchen 1 , L. Cipolotti 2 , L. Lemieux 4, G. Keir 3 , L.D. Watkins 1

1Victor Horsley department of Neurosurgery, National Hospital for 

 Neurology and Neurosurgery, London, UK;  2 Department of 

 Neuropsychology, National Hospital for Neurology and Neurosurgery,

 London, UK;  3 Department of Neuroimmunology, Institute of Neurology,

 London, UK;  4 Department of Clinical and Experimental Epilepsy, Institute

of Neurology, London, UK and MRI Unit, National Society for Epilepsy,

Chalfont St Peter, UK 

Introduction: It is still not clearly established whether the cognitive deficits

of iNPH is caused by a disturbance in CSF dynamics or an underlying

metabolic disturbance.

Objective:   To identify any possible associations between biochemical

markers, the neuroimaging characteristics and cognitive deficits of patients

undergoing investigations for possible iNPH.

Methods:   In 10 patients with iNPH a CSF sample obtained during a

lumbar puncture was analysed for several biochemical markers (lactate,

8-isoprostane, VEGF, neurofilament heavy protein (NF(h)), GFAP, Ab1-42

and tau). All patients underwent a battery of neuropsychological testing

and imaging as part of their selection process for possible CSF diversion

surgical procedure. Volumetric analysis of imaging was carried out mea-

suring the ventricular (VV), intracranial (ICV), periventricular (PVL), deep

white matter hyperintensities (DWMH) and white matter (WM) volumes.

Results:  There was a significant positive correlation (R=0.648, p=0.043)

between the levels of VEGF and the VV/ICV ratio. There was a sig-

nificant positive correlation of the levels of GFAP and the VV/DWMH

ratio (R=0.828, p=0.006). A significant negative correlation was observed

between the levels of NF(h) and the VV/ICV ratio (R=-0.657, p=0.039) and

the white matter volume (R=-0.778, p=0.023). The mean levels of GFAP

were significantly higher in the patients who performed normally in the

trail making test B, than the patients who had below normal performance

(p=0.001). No correlation was found between the cranial volumes and the

cognitive profile of the above patients.

Conclusion: The positive correlation of the VEGF levels with the severity

of ventriculomegaly may indicate that this is due to the transmantle pressure

gradient; this response may not be due to hypoxia but represent an attempt

of neuroregeneration. GFAP correlates strongly with the amount of DWMH

suggesting a degree of irreversible damage being represented by these

two markers. However, higher levels of GFAP appeared in patients whose

frontal executive functions were normal meaning that the cognitive distur-

bance might be due to some other underlying cause. Neuronal degeneration

as measured by the neurofilament levels are negatively correlated with

the volume of the white matter in these patients. The negative correlation

with the ventriculomegaly may indicating a dilution effect for NF(h).The negative association of the volumetry and cognitive profiles of these

patients may suggest a direct biochemical disturbance being responsible for

the cognitive deficit observed.

O.121   CSF and blood flows in mild cognitive impairment and

Alzheimer disease. Differential diagnosis with normal

pressure hydrocephalus?

S. Stoquart-El Sankari, C. Gondry-Jouet, D. Mbayo, O. Godefroy,

O. Balédent

University Hospital, Amiens, France

Phase-contrast magnetic resonance imaging (PC-MRI) is a noninvasive re-

liable technique which enables quantification of cerebrospinal fluid (CSF)