Chronic Headache in the Shunt-dependent Adolescent with Nearly Normal Ventricular Volume

Abstract The shunt-dependent adolescent will occasionally manifest shunt malfunction by intermittent or chronic headache without any obvious signs of increased intracranial pressure (ICP). A small percentage of these patients will have nearly normal ventricular volume, making the diagnosis and treatment difficult. The authors present a comprehensive approach to this problem that uses computerized axial tomography (CT), ICP monitoring, positive contrast or isotope shunt scan, shunt revision, subtemporal craniectomy, or medical management as the individual situation dictates. The CT scan identifies patients with nearly normal ventricular volume. ICP monitoring then determines whether there is shunt malfunction. The shunt scan aids in localization of the malfunction. For distal obstruction, a simple revision is performed. When proximal shunt malfunction occurs, either subtemporal craniectomy or revision is carried out. It has been documented that occasionally ICP is episodically increased in the absence of shunt malfunction. This is secondary to abnormal brain compliance, and subtemporal craniectomy alone or in conjunction with corticosteroids is curative. This comprehensive approach is designed to provide a method for recognizing and treating intermittently increased ICP in the shunt-dependent child.

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Continuous intracranial pressure monitoring via the shunt reservoir to assess suspected shunt malfunction in adults with hydrocephalus

Neurosurgical FOCUS ◽

10.3171/foc.2007.22.4.12 ◽

2007 ◽

Vol 22 (4) ◽

pp. 1-6 ◽

Cited By ~ 10

Author(s):

Romergryko G. Geocadin ◽

Panayiotis N. Varelas ◽

Daniele Rigamonti ◽

Michael A. Williams

Keyword(s):

Intracranial Pressure ◽

Medical Therapy ◽

Shunt Malfunction ◽

Shunt Revision ◽

Symptom Improvement ◽

Icp Monitoring ◽

Pressure Monitoring ◽

Shunt System ◽

Vp Shunt

Object The authors attempted to determine whether continuous intracrnial pressure monitoring via the shunt resevoir identifies ventriculoperitoneal (VP) shunt malfunctions that are not identified by radionuclide shunt patency study or shunt tap in adults with hydrocephalus. Methods During a 2-year period, 26 adults underwent 32 in-hospital continuous intracranial pressure (ICP) monitoring evaluations via needle access of a shunt reservoir. Monitoring was performed for 26.8 ± 13.8 hours (mean ± standard deviation). No ICP waveform abnormality was detected in 31% of the evaluations (10 of 32). In contrast, abnormalities were detected in 69% (22 of 32 evaluations), including B waves (nine of 22 evaluations), siphoning (nine of 22 evaluations), and variable ICP (two of 22 evaluations). In 20 (91%) of these 22 evaluations, the ICP abnormality was detected only after continuous ICP monitoring; in the other two evaluations, ICP became abnormal immediately on accessing the shunt reservoir. On the basis of the ICP monitoring results, shunt revision was performed in 66% (21 of 32 evaluations) and medical therapy was administered in 34% (11 of 32 evaluations). Shunt revision led to symptom improvement in 82% (18 of 22 patients) and no change in 18% (four of 22 patients); medical therapy led to improvement in 18% (two of 11 patients), worsening in 18% (two of 11 patients), and no change in 64% (seven of 11 patients; p < 0.05). Conclusions Continuous ICP monitoring via the shunt reservoir provides a more accurate assessment of shunt malfunction than transient ICP monitoring with a shunt tap or a radionuclide shunt patency study. It is a safe method for evaluating patients with suspected VP shunt malfunction, provides in vivo assessment of the effect of the shunt system on a patient's ICP, and can lead to more effective shunt revision.

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Rethinking the indications for the ventriculoperitoneal shunt tap

Journal of Neurosurgery Pediatrics ◽

10.3171/ped/2008/1/6/435 ◽

2008 ◽

Vol 1 (6) ◽

pp. 435-438 ◽

Cited By ~ 10

Author(s):

Jonathan P. Miller ◽

Steven C. Fulop ◽

Shervin R. Dashti ◽

Shenandoah Robinson ◽

Alan R. Cohen

Keyword(s):

Ventriculoperitoneal Shunt ◽

Shunt Infection ◽

Shunt Malfunction ◽

Shunt Revision ◽

Status Change ◽

Suspected Infection ◽

Evaluation Protocol ◽

Distal Obstruction ◽

Abdominal Radiographs ◽

Shunt Obstruction

Object Tapping of a suspected malfunctioning ventriculoperitoneal shunt is usually easy, sometimes informative, but also potentially misleading. The purpose of this study was to determine the effectiveness of a shunt evaluation protocol that does not involve direct shunt tapping except in rare and specific cases. Methods The authors adopted a protocol for shunt evaluation that involves shunt tapping only in selected cases of suspected infection or in patients with noncommunicating hydrocephalus and equivocal computed tomography (CT) findings of shunt infection. They then reviewed the clinical characteristics and surgical findings in 373 consecutive assessments of 155 pediatric patients who were evaluated for shunt malfunction and/or infection by using this protocol between January 2003 and December 2005. Results Mental status change and headache were the symptoms most concordant with shunt malfunction, but no symptom had a predictive value much better than 50%. Follow-up CT scans demonstrated enlarged ventricles in 72 of 126 cases of shunt revision. Among those with obstruction but without remarkable CT changes, 8 patients had evidence of distal obstruction on x-ray “shunt series” consisting of skull, chest, and abdominal radiographs, and 5 had obvious symptoms that rendered further testing unnecessary; 38 cases of obstruction were diagnosed based on elevated opening pressure on lumbar puncture (mean 34.7 cm H2O). A shunt tap was required in only 8 cases (2%). Conclusions The authors have shown that it is possible to evaluate the majority of ventricular shunt malfunctions without tapping the device. Because it is possible to diagnose shunt obstruction correctly by other means, the shunt tap may not be obligatory as a routine test of the device's patency.

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Role of radiological parameters in predicting overall shunt outcome after ventriculoperitoneal shunt insertion in pediatric patients with obstructive hydrocephalus

Neurosurgical FOCUS ◽

10.3171/2016.8.focus16263 ◽

2016 ◽

Vol 41 (5) ◽

pp. E4 ◽

Cited By ~ 4

Author(s):

Devi Prasad Patra ◽

Shyamal C. Bir ◽

Tanmoy K. Maiti ◽

Piyush Kalakoti ◽

Hugo Cuellar ◽

...

Keyword(s):

Ventriculoperitoneal Shunt ◽

Pediatric Patients ◽

Obstructive Hydrocephalus ◽

Ventricular Volume ◽

Left Ventricular ◽

Shunt Malfunction ◽

Shunt Revision ◽

Shunt Insertion ◽

Free Survival ◽

Occipital Horn

OBJECTIVE Despite significant advances in the medical field and shunt technology, shunt malfunction remains a nightmare of pediatric neurosurgeons. In this setting, the ability to preoperatively predict the probability of shunt malfunction is quite compelling. The authors have compared the preoperative radiological findings in obstructive hydrocephalus and the subsequent clinical course of the patient to determine any association with overall shunt outcome. METHODS This retrospective study included all pediatric patients (age < 18 years) who had undergone ventriculoperitoneal shunt insertion for obstructive hydrocephalus. Linear measurements were taken from pre- and postoperative CT or MRI studies to calculate different indices and ratios including Evans' index, frontal horn index (FHI), occipital horn index (OHI), frontooccipital horn ratio (FOHR), and frontooccipital horn index ratio (FOIR). Other morphological features such as bi- or triventriculomegaly, right-left ventricular symmetry, and periventricular lucency (PVL) were also noted. The primary clinical outcomes that were reviewed included the need for shunt revision, time interval to first shunt revision, frequency of shunt revisions, and revision-free survival. RESULTS A total of 121 patients were eligible for the analysis. Nearly half of the patients (47.9%) required shunt revision. The presence of PVL was associated with lower revision rates than those in others (39.4% vs 58.2%, p = 0.03). None of the preoperative radiological indices or ratios showed any correlation with shunt revision. Nearly half of the patients with shunt revision required early revision (< 90 days of primary surgery). The reduction in the FOHR was high in patients who required early shunt revision (20.16% in patients with early shunt revision vs 6.4% in patients with late shunt revision, p = 0.009). Nearly half of the patients (48.3%) requiring shunt revision ultimately needed more than one revision procedure. Greater occipital horn dilation on preoperative images was associated with a lower frequency of shunt revision, as dictated by a high OHI and a low FOIR in patients with a single shunt revision as compared with those in patients who required multiple shunt revisions (p = 0.029 and 0.009, respectively). The mean follow-up was 49.9 months. Age was a significant factor affecting shunt revision–free survival. Patients younger than 6 months of age had significantly less revision-free survival than the patients older than 6 months (median survival of 10.1 vs 94.1 months, p = 0.004). CONCLUSIONS Preoperative radiological linear indices and ratios do not predict the likelihood of subsequent shunt malfunction. However, patients who required early shunt revision tended to have greater reductions in ventricular volumes on postoperative images. Therefore a greater reduction in ventricular volume is not actually desirable, and a ventricular volume high enough to reduce intracranial pressure is instead to be aimed at for long-term shunt compliance.

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Reliability of the radiopharmaceutical shunt flow study for the detection of a CSF shunt malfunction in the presence of stable ventricular size

Journal of Neurosurgery Pediatrics ◽

10.3171/2020.4.peds2020 ◽

2020 ◽

Vol 26 (4) ◽

pp. 364-370

Author(s):

Jeffrey J. Quezada ◽

J. Gordon McComb

Keyword(s):

Ct Scan ◽

Operative Intervention ◽

Shunt Malfunction ◽

Shunt Revision ◽

Csf Shunt ◽

Technical Failure ◽

Ventricular Size ◽

Shunt Flow ◽

Programmable Valve ◽

Flow Study

OBJECTIVEThe authors sought to determine the reliability of a radiopharmaceutical (RP) shunt flow study for the detection of a CSF-diverting shunt malfunction in the presence of stable ventricular size.METHODSAfter the authors obtained IRB approval, all CSF RP shunt flow studies done between January 1, 2014, and January 1, 2019, in pediatric patients at Children’s Hospital Los Angeles were identified. Included in the study were only those patients in whom an MRI or CT scan was done during the hospital admission for shunt malfunction and showed no increase in ventricular size compared with the most recent prior MRI or CT scan when the patient was asymptomatic. Data recorded for analysis were patient age and sex, etiology of the hydrocephalus, shunt distal site, nonprogrammable versus programmable valve, operative findings if the shunt was revised, and follow-up findings for a minimum of 90 days after admission. The RP shunt flow study consisted of tapping the reservoir and injecting technetium-99m DTPA according to a set protocol.RESULTSThe authors identified 146 RP flow studies performed in 119 patients meeting the above criteria. Four of the 146 RP studies (3%) were nondiagnostic secondary to technical failure and were excluded from statistical analysis. Of the 112 normal flow studies, operative intervention was not undertaken in 102 (91%). The 10 (9%) remaining normal studies were performed in patients who underwent operative intervention, in which 8 patients had a proximal obstruction, 1 had a distal obstruction, and 1 patient had no obstruction. Of the 30 patients with abnormal flow studies, symptoms of shunt malfunction subsided in 9 (30%) patients and these patients did not undergo operative intervention. Of the 21 (70%) operated patients, obstruction was proximal in 9 patients and distal in 5, and for 7 patients the shunt tubing was either fractured or disconnected. Regression analysis indicated a significant association between the flow study interpretation and the odds for shunt revision (OR 27, 95% CI 10–75, p < 0.0001). No other clinical variables were significant. The sensitivity of a shunt flow study alone for detection of shunt malfunction in cases with stable ventricular size was the same as a shunt flow study plus an MRI or CT (70% vs 70%), but performing a shunt flow in addition to MRI or CT did increase the specificity from 92% to 100% and the accuracy from 87% to 94%.CONCLUSIONSRP shunt flow studies were of definite value in deciding whether to operatively intervene in patients with symptoms of shunt malfunction in whom no change in ventricular size was detected on current MRI or CT scans compared to scans obtained when the patients were asymptomatic.

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Radiographic assessment of snap-shunt failure

Journal of Neurosurgery Pediatrics ◽

10.3171/2010.6.peds10107 ◽

2010 ◽

Vol 6 (3) ◽

pp. 299-302 ◽

Cited By ~ 2

Author(s):

Anand I. Rughani ◽

Bruce I. Tranmer ◽

Jeffrey E. Florman ◽

James T. Wilson

Keyword(s):

Normal Values ◽

Clinical Symptoms ◽

Type System ◽

Shunt Malfunction ◽

Ct Scans ◽

Shunt Revision ◽

Ventricular Catheter ◽

Shunt Failure ◽

Shunt System ◽

Ct Finding

Accurate assessment of imaging studies in patients with ventriculoperitoneal shunts can be aided by empirical findings. The authors characterize an objective measurement easily performed on head CT scans with the goal of producing clear evidence of shunt fracture or disconnection in patients with a snap shunt–type system. The authors describe 2 cases of ventriculoperitoneal shunt failure involving a fracture and a disconnection associated with a snap-shunt assembly. In both cases the initial clinical symptoms were not convincing for shunt malfunction, and the interpretation of the CT finding failed to immediately identify the abnormality. As the clinical picture became more convincing for shunt malfunction, each patient subsequently underwent successful shunt revision. The authors reviewed the CT scans of 10 patients with an intact and functioning snap-shunt system to characterize the normal appearance of the snap-shunt connection. On CT scans the distance between the radiopaque portion of the ventricular catheter and the radiopaque portion of the reservoir dome measures an average of 4.72 mm (range 4.6–4.9 mm, 95% CI 4.63–4.81 mm). In the authors' patient with a fractured ventricular catheter, this interval measured 7.8 mm, and in the patient with a disconnection it measured 7.7 mm. In comparison with the range of normal values, a radiolucent interval significantly greater than 4.9 mm should promptly raise concern for a disconnected or fractured shunt in this system. This measurement may prove particularly useful when serial imaging is not readily available.

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Risk factors for unchanged ventricles during pediatric shunt malfunction

Journal of Neurosurgery Pediatrics ◽

10.3171/2021.6.peds2125 ◽

2021 ◽

pp. 1-7

Author(s):

Rebecca A. Reynolds ◽

Ranbir Ahluwalia ◽

Vishal Krishnan ◽

Katherine A. Kelly ◽

Jaclyn Lee ◽

...

Keyword(s):

Risk Factors ◽

Multivariable Analysis ◽

Shunt Infection ◽

Shunt Malfunction ◽

Shunt Revision ◽

Diagnostic Dilemma ◽

Wound Drainage ◽

Abdominal Pseudocyst ◽

Programmable Valve ◽

Matched Case

OBJECTIVE Children whose ventricles do not change during shunt malfunction present a diagnostic dilemma. This study was performed to identify risk factors for unchanged ventricular size at shunt malfunction. METHODS This retrospective 1:1 age-matched case-control study identified children with shunted hydrocephalus who underwent shunt revision with intraoperative evidence of malfunction at one of the three participating institutions from 1997 to 2019. Cases were defined as patients with a change of < 0.05 in the frontal–occipital horn ratio (FOR) between malfunction and baseline, and controls included patients with FOR changes ≥ 0.05. The presence of infection, abdominal pseudocyst, pseudomeningocele, or wound drainage and lack of baseline cranial imaging at the time of malfunction warranted exclusion. RESULTS Of 450 included patients, 60% were male, 73% were Caucasian, and 67% had an occipital shunt. The median age was 4.3 (IQR 0.97–9.21) years at malfunction. On univariable analysis, unchanged ventricles at malfunction were associated with a frontal shunt (41% vs 28%, p < 0.001), programmable valve (17% vs 9%, p = 0.011), nonsiphoning shunt (85% vs 66%, p < 0.001), larger baseline FOR (0.44 ± 0.12 vs 0.38 ± 0.11, p < 0.001), no prior shunt infection (87% vs 76%, p = 0.003), and no prior shunt revisions (68% vs 52%, p < 0.001). On multivariable analysis with collinear variables removed, patients with a frontal shunt (OR 1.67, 95% CI 1.08–2.70, p = 0.037), programmable valve (OR 2.63, 95% CI 1.32–5.26, p = 0.007), nonsiphoning shunt at malfunction (OR 2.76, 95% CI 1.63–4.67, p < 0.001), larger baseline FOR (OR 3.13, 95% CI 2.21–4.43, p < 0.001), and no prior shunt infection (OR 2.34, 95% CI 1.27–4.30, p = 0.007) were more likely to have unchanged ventricles at malfunction. CONCLUSIONS In a multicenter cohort of children with shunt malfunction, those with a frontal shunt, programmable valve, nonsiphoning shunt, baseline large ventricles, and no prior shunt infection were more likely than others to have unchanged ventricles at shunt failure.

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Evaluation of the ShuntCheck Noninvasive Thermal Technique for Shunt Flow Detection in Hydrocephalic Patients

Neurosurgery ◽

10.1227/neu.0b013e3181fe2db6 ◽

2011 ◽

Vol 68 (1) ◽

pp. 198-205 ◽

Cited By ~ 18

Author(s):

Joseph R. Madsen ◽

Gani S. Abazi ◽

Laurel. Fleming ◽

Mark. Proctor ◽

Ron. Grondin ◽

...

Keyword(s):

Shunt Malfunction ◽

Shunt Revision ◽

Intermittent Flow ◽

Office Visits ◽

Exact Test ◽

New Device ◽

Fisher's Exact Test ◽

Fisher’S Exact Test ◽

Sensing Skin ◽

Operative Findings

Abstract BACKGROUND: ShuntCheck (Neuro Diagnostic Devices, Inc., Trevose, Pennsylvania) is a new device designed to detect cerebrospinal fluid (CSF) flow in a shunt by sensing skin temperature downstream from a region of CSF cooled by an ice cube. OBJECTIVE: To understand its accuracy and utility, we evaluated the use of this device during routine office visits as well as during workup for suspected shunt malfunction. METHODS: One hundred shunted patients were tested, including 48 evaluated during possible shunt malfunction, of whom 24 went on to surgical exploration. Digitally recorded data were blindly analyzed and compared with surgical findings and clinical follow-up. RESULTS: Findings in the 20 malfunctioning shunts with unambiguous flow or absence of flow at surgery were strongly correlated with ShuntCheck results (sensitivity and specificity to flow of 80% and 100%, respectively, P = .0007, Fisher's exact test, measure of agreement κ = 0.8). However, the thermal determination did not distinguish patients in the suspected malfunction group who received surgery from those who were discharged without surgery (P = .248 by Fisher's exact test, κ = 0.20). Half of the patients seen in routine office visits did not have detectable flow, although none required shunt revision on clinical grounds. Intermittent flow was specifically demonstrated in one subject who had multiple flow determinations. CONCLUSION: Operative findings show that the technique is sensitive and specific for detecting flow, but failure to detect flow does not statistically predict the need for surgery. A better understanding of the normal dynamics of flow in individual patients, which this device may yield, will be necessary before the true clinical utility of non-invasive flow measurement can be assessed.

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Ventricular shunt tap as a predictor of proximal shunt malfunction in children: a prospective study

Journal of Neurosurgery Pediatrics ◽

10.3171/ped/2008/1/6/439 ◽

2008 ◽

Vol 1 (6) ◽

pp. 439-443 ◽

Cited By ~ 24

Author(s):

Brandon G. Rocque ◽

Samir Lapsiwala ◽

Bermans J. Iskandar

Keyword(s):

Prospective Study ◽

Clinical Judgment ◽

Shunt Malfunction ◽

Csf Shunt ◽

Consecutive Series ◽

Csf Flow ◽

Opening Pressure ◽

Distal Obstruction ◽

A Prospective Study ◽

Good Flow

Object The clinical diagnosis of cerebrospinal fluid (CSF) shunt malfunction can be challenging. In this prospective study, the authors evaluated a common method of interrogating shunts: the shunt tap; specifically, its ability to predict proximal malfunction. Methods The authors performed standardized shunt taps in a consecutive series of cases involving children with suspected or proven shunt malfunction, assessing flow and, when possible, opening pressure. Data were collected prospectively, and results analyzed in light of surgical findings. Results A shunt tap was performed prior to 68 operative explorations in 51 patients. Of the 68 taps, 28 yielded poor or no CSF flow on aspiration. After 26 of these 28 procedures, proximal catheter obstruction was identified. After 28 taps with good CSF return and normal or low opening pressure, 18 shunts were found to have a proximal obstruction, 8 had no obstruction, and 2 had a distal obstruction. Another 12 taps with good CSF flow had high opening pressure; subsequent surgery showed distal obstruction in 11 of the shunts, and proximal obstruction in 1. The positive predictive value of poor flow was 93%, while good flow on shunt tap predicted adequate proximal catheter function in only 55% of cases. Conclusions Poor flow of CSF on shunt tap is highly predictive of obstruction of the proximal catheter. Because not all patients with good flow on shunt tap underwent surgical shunt exploration, the specificity of this test cannot be determined. Nonetheless, a shunt tap that reveals good flow with a normal opening pressure can be misleading, and management of such cases should be based on clinical judgment.

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Sylvian aqueduct syndrome and global rostral midbrain dysfunction associated with shunt malfunction

Journal of Neurosurgery ◽

10.3171/jns.1999.90.2.0227 ◽

1999 ◽

Vol 90 (2) ◽

pp. 227-236 ◽

Cited By ~ 43

Author(s):

Giuseppe Cinalli ◽

Christian Sainte-Rose ◽

Isabelle Simon ◽

Guillaume Lot ◽

Spiros Sgouros

Keyword(s):

Pressure Gradient ◽

Obstructive Hydrocephalus ◽

Shunt Malfunction ◽

Shunt Revision ◽

Third Ventriculostomy ◽

Content Type ◽

Upward Gaze Palsy ◽

Ocular Signs ◽

Gaze Palsy ◽

Fine Print

Object. This study is a retrospective analysis of clinical data obtained in 28 patients affected by obstructive hydrocephalus who presented with signs of midbrain dysfunction during episodes of shunt malfunction.Methods. All patients presented with an upward gaze palsy, sometimes associated with other signs of oculomotor dysfunction. In seven cases the ocular signs remained isolated and resolved rapidly after shunt revision. In 21 cases the ocular signs were variably associated with other clinical manifestations such as pyramidal and extrapyramidal deficits, memory disturbances, mutism, or alterations in consciousness. Resolution of these symptoms after shunt revision was usually slow. In four cases a transient paradoxical aggravation was observed at the time of shunt revision. In 11 cases ventriculocisternostomy allowed resolution of the symptoms and withdrawal of the shunt.Simultaneous supratentorial and infratentorial intracranial pressure recordings performed in seven of the patients showed a pressure gradient between the supratentorial and infratentorial compartments, with a higher supratentorial pressure before shunt revision. Inversion of this pressure gradient was observed after shunt revision and resolution of the gradient was observed in one case after third ventriculostomy. In six recent cases, a focal midbrain hyperintensity was evidenced on T2-weighted magnetic resonance imaging sequences at the time of shunt malfunction. This rapidly resolved after the patient underwent third ventriculostomy.Conclusions. It is probable that in obstructive hydrocephalus, at the time of shunt malfunction, the development of a transtentorial pressure gradient could initially induce a functional impairment of the upper midbrain, inducing upward gaze palsy. The persistence of the gradient could lead to a global dysfunction of the upper midbrain. Third ventriculostomy contributes to equalization of cerebrospinal fluid pressure across the tentorium by restoring free communication between the infratentorial and supratentorial compartments, resulting in resolution of the patient's clinical symptoms.

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