A prospective study of cerebral blood flow and cerebrovascular reactivity to acetazolamide in 162 patients with idiopathic normal-pressure hydrocephalus

2009 ◽  
Vol 111 (3) ◽  
pp. 610-617 ◽  
Author(s):  
Chia-Cheng Chang ◽  
Hiroyuki Asada ◽  
Toshiro Mimura ◽  
Shinichi Suzuki
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Normal Pressure Hydrocephalus ◽  
Normal Pressure ◽  
Idiopathic Normal Pressure Hydrocephalus ◽  
Cerebrovascular Reactivity ◽  
Healthy Controls ◽  
Shunt Placement ◽  
Significant Difference ◽  
A Prospective Study

Object Cerebral blood flow (CBF) and cerebrovascular reactivity (CVR) to acetazolamide were investigated prospectively in 162 patients with a proposed diagnosis of idiopathic normal-pressure hydrocephalus (NPH). The aim of this study was to assess the usefulness of the measurement of CBF and CVR in determining which patients would be likely to benefit from shunt placement. Methods The mean CBF of the whole brain was measured according to the Patlak plot method by using technetium-99m hexamethylpropyleneamine oxime. The CVR value was obtained from the response to administration of 500 mg acetazolamide and calculated as the percentage change from the baseline mean CBF value. Results One hundred forty-six patients (90.1%) responded to shunt placement (“responders”), but 16 patients (9.9%) did not (“nonresponders”). No significant difference in preoperative CBF was observed between responders and nonresponders. Preoperative CVR was significantly impaired (p < 0.0025) in responders compared with healthy controls, but not in nonresponders. Responders with the incomplete triad had a significant reduction (p < 0.001) in preoperative CVR, but not in preoperative CBF, compared with healthy controls. Responders with the complete triad had significantly lower preoperative CBF and CVR than those with the incomplete triad (p < 0.01 and p < 0.05, respectively). Postoperative CBF and CVR increased significantly (p < 0.025 and p < 0.001, respectively) in responders. Conclusions Both CBF and CVR decrease with the development of NPH, suggesting that hemodynamic ischemia may be responsible for manifestation of the symptoms. Impaired CVR and reduced CBF with the development of symptoms can be proposed as diagnostic criteria for idiopathic NPH.

scholarly journals Response of cerebral blood flow and cerebrovascular reactivity to acetazolamide in patients with dementia and idiopathic normal-pressure hydrocephalus

1999 ◽  
Vol 7 (4) ◽  
pp. E11
Author(s):  
Chia-Cheng Chang ◽  
Nobumasa Kuwana ◽  
Susumu Ito ◽  
Tadashi Ikegami
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Normal Pressure Hydrocephalus ◽  
Photon Emission ◽  
Normal Pressure ◽  
Idiopathic Normal Pressure Hydrocephalus ◽  
Cerebrovascular Reactivity ◽  
Significant Difference ◽  
The Mean ◽  
Normal Controls

The responses of cerebral blood flow (CBF) and cerebrovascular reactivity (CVR) to administration of acetazolamide were investigated in 16 patients with dementia and ventriculomegaly to clarify the cerebral hemodynamics in patients with idiopathic normal-pressure hydrocephalus (NPH). The mean CBF velocity in the whole brain was measured by the Patlak plot method by using technetium-99m hexamethylpropyleneamine oxime single-photon emission computerized tomography. The CVR values were obtained from the response to administration of 500 mg of acetazolamide and calculated as the percentage of change from the baseline mean CBF value. The mean CBF value was significantly reduced (p < 0.01) in six patients with (35.2 ± 5 ml/100 g/minute) and 10 patients without (33.5 ± 2.8 ml/100 g/minute) NPH compared with the age-matched normal controls (40.8 ± 3.2 ml/100 g/minute), showing no significant difference. The CVR was significantly impaired in patients with NPH (0.8 ± 1.7%; p < 0.001), whereas in patients without NPH preserved CVR (11.3 ± 3%) was demonstrated compared with the normal controls (14.7 ± 1.1%). In patients with NPH a significantly lower CVR (p < 0.001) was shown than in those without NPH. The CVR significantly increased (p < 0.001) after placement of a shunt in patients with NPH. Reductions in both CBF and CVR may be diagnostic indicators of NPH in patients with dementia in whom ventriculomegaly is present. In patients with dementia and idiopathic NPH both reduced CBF and extremely impaired CVR are shown. The results of the present study suggest that ischemia due to the process of NPH is responsible for the reduction of CBF and manifestation of symptoms in patients with idiopathic NPH.

scholarly journals Pre-and postoperative cerebral blood flow changes in patients with idiopathic normal pressure hydrocephalus measured by computed tomography (CT)-perfusion

2016 ◽  
Vol 36 (10) ◽  
pp. 1755-1766 ◽  
Author(s):  
Doerthe Ziegelitz ◽  
Jonathan Arvidsson ◽  
Per Hellström ◽  
Mats Tullberg ◽  
Carsten Wikkelsø ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Normal Pressure Hydrocephalus ◽  
Normal Pressure ◽  
Idiopathic Normal Pressure Hydrocephalus ◽  
Lentiform Nucleus ◽  
Spatial Coverage ◽  
Potential Biomarker ◽  
Subcortical Regions

In idiopathic normal pressure hydrocephalus (iNPH), the cerebral blood flow (CBF) is of pathophysiological interest and a potential biomarker. Computed tomography perfusion (CTP), an established technique with high spatial resolution and quantitative measurements, has not yet been used in the iNPH context. If CTP were sensitive to the CBF levels and changes in iNPH, this technique might provide diagnostic and prognostic absolute perfusion thresholds. The aim of this work was to determine the applicability of CTP to iNPH. CBF measurements of 18 patients pre- and 17 three months postoperatively, and six healthy individuals (HI) were evaluated in 12 cortical and subcortical regions of interest. Correlations between CBF and symptomatology were analyzed in shunt-responders. Compared to HI, the preoperative CBF in iNPH was significantly reduced in normal appearing and periventricular white matter (PVWM), the lentiform nucleus and the global parenchyma. No CBF differences were shown between responders and non-responders. In responders, the CBF recovered postoperatively by 2.5–32% to approximately the level of HI, but remained significantly decreased in the PVWM of non-responders. The pre- and postoperative CBF of cortical and subcortical regions correlated with the intensity of symptoms. In spite of limited spatial coverage, CTP can measure CBF changes in iNPH.

scholarly journals Prevalence of Cervical Stenosis and Myelopathy in Patients With Idiopathic Normal Pressure Hydrocephalus

Neurosurgery ◽  
2019 ◽  
Vol 66 (Supplement_1) ◽  
Author(s):  
Ryan M Naylor ◽  
Karina Lenartowicz ◽  
Jonathan Graff-Radford ◽  
Jeremy Cutsforth-Gregory ◽  
Benjamin D Elder
Keyword(s):  
Cervical Spine ◽  
Normal Pressure Hydrocephalus ◽  
Cervical Myelopathy ◽  
Clinical Manifestations ◽  
Normal Pressure ◽  
Idiopathic Normal Pressure Hydrocephalus ◽  
Decompression Surgery ◽  
Consecutive Series ◽  
Cervical Stenosis ◽  
Shunt Placement

Abstract INTRODUCTION Both idiopathic normal pressure hydrocephalus (iNPH) and cervical myelopathy may result in progressive gait impairment. It is possible that some of the patients who do not respond to shunting despite a positive tap test may have gait dysfunction from cervical myelopathy. The objective of this study was to determine the prevalence of cervical stenosis with or without myelopathy in patients with iNPH. METHODS We screened a consecutive series of patients who underwent shunt placement for iNPH for comorbid cervical stenosis. Clinical manifestations of iNPH and cervical myelopathy, grade of cervical stenosis based on previously published criteria, cervical spine surgical intervention, timing of intervention, and outcomes were recorded. RESULTS A total of 42 patients with iNPH were included for analysis. Slightly more patients were male (65%), with a mean age of 75 yr (SD 7 yr) for the entire cohort. All patients presented with gait disturbances and underwent cervical spine MRI. 30/42 (71%) had at least cervical stenosis, while 7/42 (17%) had significant (grade 2-3) cervical stenosis with myelopathy requiring surgical decompression. All patients with grade 2-3 cervical stenosis and symptoms of cervical myelopathy in addition to iNPH underwent cervical decompression surgery. CONCLUSION Clinically significant cervical stenosis is highly prevalent in patients with iNPH, though this finding requires validation in a larger population. Based on these results, cervical imaging should be considered preoperatively or in patients whose gait does not improve after shunt placement.

scholarly journals Phase-contrast magnetic resonance imaging reveals net retrograde aqueductal flow in idiopathic normal pressure hydrocephalus

2016 ◽  
Vol 124 (6) ◽  
pp. 1850-1857 ◽  
Author(s):  
Geir Ringstad ◽  
Kyrre Eeg Emblem ◽  
Per Kristian Eide
Keyword(s):  
Flow Rate ◽  
Normal Pressure Hydrocephalus ◽  
Phase Contrast ◽  
Normal Pressure ◽  
Idiopathic Normal Pressure Hydrocephalus ◽  
Conservative Group ◽  
Shunt Placement ◽  
Before And After ◽  
Shunt Group ◽  
Antegrade Flow

OBJECT The objective of this study was to assess the net aqueductal stroke volume (ASV) and CSF aqueductal flow rate derived from phase-contrast MRI (PC-MRI) in patients with probable idiopathic normal pressure hydrocephalus (iNPH) before and after ventriculoperitoneal shunt surgery, and to compare observations with intracranial pressure (ICP) scores. METHODS PC-MRI at the level of the sylvian aqueduct was undertaken in patients undergoing assessment for probable iNPH. Aqueductal flow in the craniocaudal direction was defined as positive, or antegrade flow, and net ASV was calculated by subtracting retrograde from antegrade aqueductal flow. Aqueductal flow rate per minute was calculated by multiplying net ASV by heart rate. During the same hospital admission, clinical examination was performed using NPH score and overnight continuous ICP monitoring. Twelve patients were followed prospectively 12 months after shunt placement with clinical assessment and a second PC-MRI. The study also included 2 healthy controls. RESULTS Among 21 patients examined for iNPH, 17 (81%) received a shunt (shunt group), and 4 were treated conservatively (conservative group). Among the patients with shunts, a clinical improvement was observed in 16 (94%) of the 17. Net ASV was negative in 16 (76%) of 21 patients before shunt placement and in 5 (42%) of 12 patients after shunt placement, and increased from a median of −5 μl (range −175 to 27 μl) to a median of 1 μl (range −61 to 30 μl; p = 0.04). Among the 12 patients with PC-MRI after shunt placement, 11 were shunt responders, and in 9 of these 11 either a reduced magnitude of retrograde aqueductal flow, or a complete reversal from retrograde to antegrade flow, occurred. Net ASV was significantly lower in the shunt group than in the conservative group (p = 0.01). The aqueductal flow rate increased from −0.56 ml/min (range −12.78 to 0.58 ml/min) to 0.06 ml/min (range −4.51 to 1.93 ml/min; p = 0.04) after shunt placement. CONCLUSIONS In this cohort of patients with iNPH, retrograde net aqueductal flow was observed in 16 (76%) of 21 patients. It was reversed toward the antegrade direction after shunt placement either by magnitude or completely in 9 (75%) of 12 patients examined using PC-MRI both before and after shunt placement (p = 0.04); 11 of the 12 were shunt responders. The study results question previously established concepts with respect to both CSF circulation pathways and CSF formation rate.

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