Changes in Ventricular and Gray Matter Volumes Following Shunt Placement in Patients with Normal Pressure Hydrocephalus

2020 ◽  
Author(s):  
Petrice Cogswell
Keyword(s):  
Gray Matter ◽  
Normal Pressure Hydrocephalus ◽  
Normal Pressure ◽  
Shunt Placement ◽  
Gray Matter Volumes

Motor cortex disinhibition in normal-pressure hydrocephalus

2012 ◽  
Vol 116 (2) ◽  
pp. 453-459 ◽  
Author(s):  
Andrei V. Chistyakov ◽  
Hava Hafner ◽  
Alon Sinai ◽  
Boris Kaplan ◽  
Menashe Zaaroor
Keyword(s):  
Motor Cortex ◽  
Healthy Volunteers ◽  
Normal Pressure Hydrocephalus ◽  
Close Association ◽  
Motor Evoked Potential ◽  
Normal Pressure ◽  
Corticospinal Excitability ◽  
Conduction Time ◽  
Shunt Placement ◽  
Resting Motor Threshold

Object Previous studies have shown a close association between frontal lobe dysfunction and gait disturbance in idiopathic normal-pressure hydrocephalus (iNPH). A possible mechanism linking these impairments could be a modulation of corticospinal excitability. The aim of this study was 2-fold: 1) to determine whether iNPH affects corticospinal excitability; and 2) to evaluate changes in corticospinal excitability following ventricular shunt placement in relation to clinical outcome. Methods Twenty-three patients with iNPH were examined using single- and paired-pulse transcranial magnetic stimulation of the leg motor area before and 1 month after ventricular shunt surgery. The parameters of corticospinal excitability assessed were the resting motor threshold (rMT), motor evoked potential/M-wave area ratio, central motor conduction time, intracortical facilitation, and short intracortical inhibition (SICI). The results were compared with those obtained in 8 age-matched, healthy volunteers, 19 younger healthy volunteers, and 9 age-matched patients with peripheral neuropathy. Results Significant reduction of the SICI associated with a decrease of the rMT was observed in patients with iNPH at baseline evaluation. Ventricular shunt placement resulted in significant enhancement of the SICI and increase of the rMT in patients who markedly improved, but not in those who failed to improve. Conclusions This study demonstrates that iNPH affects corticospinal excitability, causing disinhibition of the motor cortex. Recovery of corticospinal excitability following ventricular shunt placement is correlated with clinical improvement. These findings support the view that reduced control of motor output, rather than impairment of central motor conduction, is responsible for gait disturbances in patients with 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.

Ventriculoperitoneal Shunting of Idiopathic Normal Pressure Hydrocephalus Increases Midbrain Size: A Potential Mechanism for Gait Improvement

Neurosurgery ◽  
2006 ◽  
Vol 59 (4) ◽  
pp. 847-851 ◽  
Author(s):  
J Mocco ◽  
Matthew I. Tomey ◽  
Ricardo J. Komotar ◽  
William J. Mack ◽  
Steven J. Frucht ◽  
...  
Keyword(s):  
Normal Pressure Hydrocephalus ◽  
Ventriculoperitoneal Shunt ◽  
Medical Center ◽  
Normal Pressure ◽  
Idiopathic Normal Pressure Hydrocephalus ◽  
Cross Sectional ◽  
Mean Values ◽  
Shunt Placement ◽  
Ventriculoperitoneal Shunting ◽  
The Mean

Abstract OBJECTIVE: Idiopathic normal pressure hydrocephalus (INPH) is characterized by a classic clinical triad of symptoms, including dementia, urinary incontinence, and gait disturbance. Recent work has demonstrated that the maximal midbrain anteroposterior (AP) diameter is significantly smaller in patients with INPH than in healthy, age-matched controls. The current study was undertaken to determine the effect of ventriculoperitoneal shunt placement on midbrain dimensions in INPH patients. METHODS: Twelve consecutive INPH patients undergoing ventriculoperitoneal shunt placement with pre- and postoperative computed tomographic scans at the Columbia University Medical Center were enrolled. Each patient's pre- and postoperative maximum AP and left-to-right diameters of the midbrain at the pontomesencephalic junction were independently measured in a blinded fashion by two of the authors. The average value of each dimension was computed by calculating the mean values of the measurements of the two observers. RESULTS: Both the mean AP diameter (preoperative mean, 2.06 ± 0.04 cm; postoperative mean, 2.27 ± 0.05; P = 0.0007) and left-to-right diameter (preoperative mean, 2.80 ± 0.07; postoperative mean, 3.03 ± 0.08; P = 0.0029) increased from pre- to postoperative imaging. The approximate cross-sectional area determined as the product of AP and left-to-right diameters also increased from pre- to postoperative images (preoperative mean, 5.79 ± 0.22 cm2; postoperative mean, 6.90 ± 0.25 cm2; P = 0.00049). CONCLUSION: This study provides supportive evidence that midbrain cytoarchitecture may play a role in the pathophysiology and post-ventriculoperitoneal shunt gait improvement of INPH patients.

scholarly journals Postshunt Cognitive and Functional Improvement in Idiopathic Normal Pressure Hydrocephalus

Neurosurgery ◽  
2011 ◽  
Vol 68 (2) ◽  
pp. 416-419 ◽  
Author(s):  
Heather Katzen ◽  
Lisa D. Ravdin ◽  
Stephanie Assuras ◽  
Roberto Heros ◽  
Michael Kaplitt ◽  
...  
Keyword(s):  
Normal Pressure Hydrocephalus ◽  
Repeated Measures ◽  
Normal Pressure ◽  
Idiopathic Normal Pressure Hydrocephalus ◽  
Practice Effects ◽  
Control Group ◽  
Significant Group ◽  
Shunt Placement ◽  
Cognitive Improvement ◽  
Control Subjects

Abstract BACKGROUND: Improvement in gait after shunt placement has been well documented in idiopathic normal pressure hydrocephalus (iNPH); however, controversy remains regarding the extent and pattern of postsurgical cognitive changes. Conflicting findings may be explained by variability in both test selection and follow-up intervals across studies. Furthermore, most investigations lack a control group, making it difficult to disentangle practice effects from a true treatment effect. OBJECTIVE: To examine postshunt changes in a sample of well-characterized iNPH participants compared with a group of age- and education-matched healthy control subjects. METHODS: We identified 12 participants with iNPH undergoing shunt placement and 9 control participants. All participants were evaluated with comprehensive neuropsychological testing and standardized gait assessment at baseline and were followed up for 6 months. RESULTS: Repeated-measures analysis of variance revealed a significant group- (iNPH and control) by-time (baseline and 6 months) interaction for Trailmaking Test B: (P < .003) and Symbol Digit Modalities (P < .02), with greater improvement in iNPH participants relative to control subjects. In addition, the iNPH group showed greater improvement in gait (P < .001) and caregivers reported improved activities of daily living (P < .01) and reduced caregiver distress (P < .01). CONCLUSION: This study demonstrates improvements in mental tracking speed and sustained attention 6 months after shunt placement in iNPH. The present investigation is the first study to use a controlled design to show that cognitive improvement in iNPH is independent of practice effects. Furthermore, these findings indicate functional and quality-of-life improvements for both the shunt responder and their caregiver.

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