Symptomatic cerebral vasospasm following resection of a medulloblastoma in a child

Establishing normal Lindegaard Ratio in healthy children 10-16 years of age

PURPOSE

Transcranial doppler based diagnostic criteria for cerebral vasospasm are not well established in the pediatric population because there is no published normative data to support the diagnosis. Studies have relied on expert consensus, but the definitions have not been validated in children diagnosed with angiographic evidence of vasospasm. Obtaining normative data is a prerequisite to defining pediatric cerebral vasospasm and the Lindegaard Ratio (LR). In this study, we obtained normative data and calculation of the normal LR from healthy children aged 10-16 years.

METHODS

TCD and carotid ultrasonography was used to measure steady state velocities of both the middle cerebral artery (VMCA) and the extracranial internal cerebral artery (VEICA) in healthy children aged 10-16 years. Demographic information, hemodynamic characteristics and the calculated LR (VMCA/VEICA) was determined for each subject using descriptive statistics.

RESULTS

Of the 26 healthy children, 13 were male and 13 were female. VMCA ranged between 53 and 93 cm/sec. LR ranged between 1 and 2.2 for the cohort. VMCA for both males and females were within 2 standard deviations (SD) of the normal mean flow velocity. As the VMCA velocities approached 2 SD above the mean, LR did not exceed 2.2.

CONCLUSION

Our results help define a threshold for LR which can be used to establish radiographic criteria for cerebral vasospasm in children. Our data suggests that using VMCA criteria alone would overestimate cerebral vasospasm and raises question of whether an LR threshold other than 3 is more appropriate for the cut off between hyperemia versus vasospasm in children.

Management of postoperative cerebral vasospasm in skull base surgeries: A systematic review of case reports and series

Background

This study provides a comprehensive overview of the management of postoperative vasospasm after skull base surgeries. This phenomenon is rare but can be of serious sequelae.

Methods

Medline, Embase, and PubMed Central were searched, along with examining the references of the included studies. Only case reports and series that reported vasospasm following a skull base pathology were incorporated. Cases with pathologies other than skull base, subarachnoid hemorrhage, aneurysm, and reversible cerebral vasoconstriction syndrome were excluded from the study. Quantitative data were presented as mean (Standard Deviation) or median (range), accordingly, while qualitative data were presented as frequency (percentage). Chi- square test and one-way analysis of variance were used to assess for any association between the different factors and patient outcomes.

Results

We had a total of 42 cases extracted from the literature. The mean age was 40.1 (±16.1) with approximately equal males and females (19 [45.2%] and 23 [54.8%], respectively). The time to develop vasospasm after the surgery was 7 days (±3.7). Most of the cases were diagnosed by either angiogram or magnetic resonance angiography. Seventeen of the 42 patients had pituitary adenoma as the pathology. Anterior circulation was nearly affected in all patients. For management, most patients received pharmacological with supportive management. Twenty-three patients had an incomplete recovery as a result of vasospasm.

Conclusion

Vasospasm following skull base operations can affect males and females, and most patients in this review were middle-aged adults. The outcome of patients varies; however, most patients did not achieve a full recovery. There was no correlation between any factors and the outcome.

Arterial Spin-Labeling Perfusion Metrics in Pediatric Posterior Fossa Tumor Surgery

BACKGROUND AND PURPOSE

Pediatric posterior fossa tumors often present with hydrocephalus; postoperatively, up to 25% of patients develop cerebellar mutism syndrome. Arterial spin-labeling is a noninvasive means of quantifying CBF and bolus arrival time. The aim of this study was to investigate how changes in perfusion metrics in children with posterior fossa tumors are modulated by cerebellar mutism syndrome and hydrocephalus requiring pre-resection CSF diversion.

MATERIALS AND METHODS

Forty-four patients were prospectively scanned at 3 time points (preoperatively, postoperatively, and at 3-month follow-up) with single- and multi-inflow time arterial spin-labeling sequences. Regional analyses of CBF and bolus arrival time were conducted using coregistered anatomic parcellations. ANOVA and multivariable, linear mixed-effects modeling analysis approaches were used. The study was registered at clinicaltrials.gov (NCT03471026).

RESULTS

CBF increased after tumor resection and at follow-up scanning (P = .045). Bolus arrival time decreased after tumor resection and at follow-up scanning (P = .018). Bolus arrival time was prolonged (P = .058) following the midline approach, compared with cerebellar hemispheric surgical approaches to posterior fossa tumors. Multivariable linear mixed-effects modeling showed that regional perfusion changes were more pronounced in the 6 children who presented with symptomatic obstructive hydrocephalus requiring pre-resection CSF diversion, with hydrocephalus lowering the baseline mean CBF by 20.5 (standard error, 6.27) mL/100g/min. Children diagnosed with cerebellar mutism syndrome (8/44, 18.2%) had significantly higher CBF at follow-up imaging than those who were not (P = .040), but no differences in pre- or postoperative perfusion parameters were seen.

CONCLUSIONS

Multi-inflow time arterial spin-labeling shows promise as a noninvasive tool to evaluate cerebral perfusion in the setting of pediatric obstructive hydrocephalus and demonstrates increased CBF following resolution of cerebellar mutism syndrome.

Symptomatic cerebral vasospasm following posterior fossa hemangioblastoma resection: illustrative case

BACKGROUND

Symptomatic cerebral vasospasm following posterior fossa intra-axial tumor resection is a rare phenomenon with only seven cases previously reported in the literature. The condition appears distinct to vasospasm following supratentorial tumor resection and extra-axial tumor resection of the posterior fossa. It shares, however, similarities with vasospasm following aneurysmal subarachnoid hemorrhage.

OBSERVATIONS

The authors describe their experience with a 23-year-old female who developed delayed symptomatic vasospasm following resection of a left parapontine cerebellar hemangioblastoma. Tumor resection was complicated by rupture of a fragile arterialized vein, resulting in significant hemorrhage. The patient developed several episodes of focal and variably reversible neurological deficit. These clinical signs corresponded with angiographically confirmed vasospasm, which responded to standard therapies for vasospasm post aneurysmal subarachnoid hemorrhage.

LESSONS

This case and literature review highlight that symptomatic vasospasm is a rare, potentially highly morbid complication of posterior fossa intra-axial tumor resection. This phenomenon may be related to significant intraoperative or postoperative hemorrhage. Postoperative radiological findings such as high risk modified Fisher scale hemorrhage could alert clinicians to this condition.

Clinical applications of transcranial Doppler in non-trauma critically ill children: a scoping review

BACKGROUND

Many applications of transcranial Doppler (TCD) as a diagnosis or monitoring tool have raised interest in the last decades. It is important that clinicians know when and how to perform TCD in this population, what parameter to assess and monitor and how to interpret it.

OBJECTIVE

This review aims to describe the emerging clinical applications of TCD in critically ill children excluding those suffering from trauma.

METHODS

Databases Web of Science, Cochrane and PubMed were searched in May 2020. We considered all publications since the year 2000 addressing the use of TCD as a prognostic, diagnostic or follow-up tool in children aged 0 to 15 years admitted to intensive care or emergency units, excluding neonatology and traumatic brain injury. Two independent reviewers selected 82 abstracts and full-text articles from the 2011 unique citations identified at the outset.

RESULTS

TCD provides crucial additional information at bedside about cerebrovascular hemodynamics. Many clinical applications include the diagnosis and management of various medical and surgical neurologic conditions (central nervous system infections, arterial ischemic stroke, subarachnoid hemorrhage and vasospasm, brain death, seizures, metabolic disease, hydrocephalus) as well as monitoring the impact systemic conditions on brain perfusion (hemodynamic instability, circulatory assistance).

CONCLUSION

To conclude, TCD has become an invaluable asset for non-invasive neuromonitoring in critically ill children excluding those suffering from trauma. However, the scope of TCD remains unclearly defined yet and reference values in critically ill children are still lacking.

Cerebral Vasospasm after Posterior Fossa Tumor Surgery: A Case Report and Literature Review

INTRODUCTION

This report presents an unusual case of symptomatic vasospasm following resection of posterior fossa tumor in a 9-year-old female patient. To the best of our knowledge, only 6 pediatric cases of vasospasms as a complication of brain tumor surgery have been reported in the literature previously.

CASE PRESENTATION

After an uneventful 12 days postoperatively, the patient suddenly presented with acute neurological deterioration on the 13th day and MR angiography showed bilateral narrowing of the supraclinoid segments of the internal carotid artery and the proximal parts of the A1 and M1 segments. Hypervolemia and vasospasm treatments were administered, and the patient exhibited no neurological deficit at the time of discharge, confirmed via normal MRI.

CONCLUSION

Early diagnosis and intervention in case of suspected symptomatic cerebral vasospasm after pediatric posterior fossa tumor surgery are essential in order to achieve favorable outcomes.

Cerebral Vasospasm after Open Fenestration of an Arachnoid Cyst in a 4-Year-Old Boy: Case Report and Review of the Literature

Cerebral vasospasm is associated with significant morbidity, and most commonly occurs following subarachnoid hemorrhage. Rarely, vasospasm can follow tumor resection and traumatic brain injury. We present the first reported case of a young child who developed diffuse vasospasm following open fenestration of an arachnoid cyst and was promptly treated, with full recovery of neurologic function. Although vasopasm after arachnoid cyst fenestration is rare, it can be included in the differential for a new focal neurologic deficit.

Predictors of Acute Vertebrobasilar Vasospasm following Tumor Resection in the Foramen Magnum Region

Objective

Cerebral vasospasm can occur after skull base tumor removal. Few studies concentrated on the posterior circulation vasospasm after tumor resection in the posterior fossa. We aimed to identify the risk factors associated with postoperative vertebrobasilar vasospasm after tumor resection in the foramen magnum.

Methods

We retrospectively reviewed the data of 62 patients with tumors in the foramen magnum at our institution from January 2010 to January 2015. The demographic data, tumor features, surgical characteristics were collected. Vertebrobasilar vasospasm was evaluated by bedside transcranial Doppler before surgery and on postoperative day 1, 3, 7. Univariate and multivariate analyses were performed to determine the predictors of postoperative vasospasm in the posterior circulation.

Results

Vertebrobasilar vasospasm was detected in 28 (53.8%) of the 62 patients at a mean time of 3.5 days after surgery. There were 5 (8%) patients with severe vasospasm according to the grading criteria. Age, tumor type, tumor size, vertebral artery encasement, and surgical time were significantly related to vasospasm in the univariate analysis. Further multivariate analysis demonstrated that only age and vertebral artery encasement were independent risk factors predicting the occurrence of postoperative vertebrobasilar vasospasm.

Conclusions

The incidence of acute vertebrobasilar vasospasm is not uncommon after foramen magnum tumor resection. Age and vertebral artery encasement are significantly correlated with postoperative vasospasm. Close monitoring of vasospasm should be given to patients with younger age and the presence of vertebral artery encasement on the preoperative imaging to facilitate early diagnosis and intervention.

Transcranial Doppler Sonography in Pediatric Neurocritical Care: A Review of Clinical Applications and Case Illustrations in the Pediatric Intensive Care Unit

Transcranial Doppler sonography is a noninvasive, real-time physiologic monitor that can detect altered cerebral hemodynamics during catastrophic brain injury. Recent data suggest that transcranial Doppler sonography may provide important information about cerebrovascular hemodynamics in children with traumatic brain injury, intracranial hypertension, vasospasm, stroke, cerebrovascular disorders, central nervous system infections, and brain death. Information derived from transcranial Doppler sonography in these disorders may elucidate underlying pathophysiologic characteristics, predict outcomes, monitor responses to treatment, and prompt a change in management. We review emerging applications for transcranial Doppler sonography in the pediatric intensive care unit with case illustrations from our own experience.

Time-dependent structural changes of the dentatothalamic pathway in children treated for posterior fossa tumor

BACKGROUND AND PURPOSE

Injury to the dentatothalamic pathway that originates in the cerebellum has been suggested as a mechanism for neurologic complications in children treated for posterior fossa tumors. We hypothesized that time-dependent changes occur in the dentatothalamic pathway.

MATERIALS AND METHODS

Diffusion tensor evaluation was performed in 14 children (median age, 4.1 years; age range, 1-20 years) who underwent serial MR imaging at 3T as part of routine follow-up after posterior fossa tumor resection with or without adjuvant therapy. Tensor metrics were obtained in the acute (≤1 week), subacute (1 to <6 months), and chronic (≥6 months) periods after surgery. We evaluated the following dentatothalamic constituents: bilateral dentate nuclei, cerebellar white matter, and superior cerebellar peduncles. Serial dentate nuclei volumes were also obtained and compared with the patient's baseline.

RESULTS

The most significant tensor changes to the superior cerebellar peduncles and cerebellar white matter occurred in the subacute period, regardless of the tumor pathology or therapy regimen, with signs of recovery in the chronic period. However, chronic volume loss and reduced mean diffusivity were observed in the dentate nuclei and did not reverse. This atrophy was associated with radiation therapy and symptoms of ataxia.

CONCLUSIONS

Longitudinal diffusion MR imaging in children treated for posterior fossa tumors showed time-dependent tensor changes in components of the dentatothalamic pathway that suggest evolution of structural damage with inflammation and recovery of tissue directionality. However, the dentate nuclei did not show tensor or volumetric recovery, suggesting that the injury may be chronic.