Acute symptomatic cerebellar tonsillar herniation following intraoperative lumbar drainage

Surgical Outcomes in Chiari 1 and Chiari 1.5 Malformation Treated by Posterior Fossa Reconstruction: A Comprehensive Analysis of 110 Pediatric Cases and Literature Review

Background/Objectives: The management of Chiari malformations (CMs) remains a clinical challenge and a topic of great controversy. Results may vary between children and adults. The purpose of the current single-center study is to critically assess the one-year surgical outcomes of a cohort of 110 children with CM-1 or CM-1.5 who were treated using "posterior fossa reconstruction" (PFR), a surgical technique described in 1994 that has since been used in both adults and children. We also review the literature and discuss the possible causes of the drawbacks and pitfalls in children in whom PFR was ineffective in controlling the disease. Methods: The present cohort was selected from a prospective registry of adults and children with CMs collected since 2006. Patients included in this study were selected from a group of children with CMs who were operated on in our Pediatric Neurosurgical Unit between 1 January 2007 and 31 November 2023. Surgical outcome was defined based on clinical and neuroradiological results as very good, good, or bad. Results: The mean age of our child cohort was 9.9 ± 4.7 years, with 54 girls (49%) and 56 boys (51%). Sixty-six children had CM-1 (60%) while forty-four had CM-1.5 (40%). Following surgery, there was no neurological worsening or death among the children. Most children (70%) had an uneventful recovery and were discharged home on average one week after surgery. However, in 33 children (30%), we recorded at least one postoperative adverse event. Aseptic meningitis syndrome was the most frequent adverse event (n = 25, 22.7%). The final surgical outcome was evaluated one year after PFR by using both clinical and neuroradiological results. The one-year surgical outcome was excellent in 101 children (91.9%), good in 5 (4.5%), and bad in 4 (3.6%). Conclusions: PFR significantly enlarges the volume of the posterior fossa and recreates a CSF environment that generates buoyancy of the cerebellum, with a high percentage of excellent and good clinical results evaluated one year post-surgery.

A Critical Update of the Classification of Chiari and Chiari-like Malformations

Chiari malformations are a group of craniovertebral junction anomalies characterized by the herniation of cerebellar tonsils below the foramen magnum, often accompanied by brainstem descent. The existing classification systems for Chiari malformations have expanded from the original four categories to nine, leading to debates about the need for a more descriptive and etiopathogenic terminology. This review aims to examine the various classification approaches employed and proposes a simplified scheme to differentiate between different types of tonsillar herniations. Furthermore, it explores the most appropriate terminology for acquired herniation of cerebellar tonsils and other secondary Chiari-like malformations. Recent advances in magnetic resonance imaging (MRI) have revealed a higher prevalence and incidence of Chiari malformation Type 1 (CM1) and identified similar cerebellar herniations in individuals unrelated to the classic phenotypes described by Chiari. As we reassess the existing classifications, it becomes crucial to establish a terminology that accurately reflects the diverse presentations and underlying causes of these conditions. This paper contributes to the ongoing discussion by offering insights into the evolving understanding of Chiari malformations and proposing a simplified classification and terminology system to enhance diagnosis and management.

Analysis of risk factors and treatment strategies for lumbar cistern blockage after craniocerebral surgery

Objective

Lumbar cistern blockage is a common complication of continuous lumbar cistern drainage. This paper analyzes the risk factors for lumbar cistern blockage drainage due to various causes and proposes a series of prevention and intervention measures to reduce blockage or improve recanalization after blockage.

Methods

The clinical data of 637 patients with various lesions who underwent lumbar cistern drainage in our hospital were retrospectively collected and analyzed. Perioperative clinical and imaging data were assessed. Variates were analyzed using univariate and multivariate logistic regression analyses.

Results

A total of 13.7% (87/637) of patients had lumbar cistern blockage. Multivariate analysis revealed that drainage time (≥7 days), CSF volume <200 (mL/d), CSF leakage, and abnormal CSF properties were predictors of lumbar cistern blockage. Reducing the probability of lumbar cistern blockage can be achieved by repeatedly flushing, increasing the drainage flow and shortening the drainage time. The recanalization rate after blockage was 67.8% (59/87). After the drainage tube was removed, no complications related to the drainage tube occurred during the 1-week follow-up.

Conclusion

Lumbar cistern blockage is the main reason for poor drainage. Prevention or early intervention can effectively reduce the probability of blockage and achieve the purpose of drainage of cerebrospinal fluid.

Natural History and Conservative Treatment Options in Chiari Malformation Type I in Adults: A Literature Update

Over the years, knowledge regarding the natural history of Chiari malformation type I (CM-I) has improved. However, there are still uncertainties in the literature regarding asymptomatic and oligosymptomatic patients with CM-I. We performed a literature review in order to determine the natural history of CM-I in symptomatic patients who were not operated and in asymptomatic adult patients. Among symptomatic patients, the most frequent symptom was headache (77%). Cough-related headache alone (34%), migraine-related headache alone (21.4%), and both cough- and migraine-related headaches (21.8%) were the most prevalent forms of headache. Some symptoms improved more effectively with surgical treatment options; cough-related headaches improved by 95% following surgery and by 40% following conservative treatment. Other headache types improved by 93% and 61.5% following conservative and surgical treatments, respectively. Patients diagnosed with asymptomatic or oligosymptomatic CM-I may improve over time or stabilize with conservative treatment. There is great heterogeneity in the literature regarding the diagnostic criteria for CM-I. Owing to the heterogeneity among the articles identified for this review, there is no consensus regarding the precise indications for surgery in asymptomatic patients. The natural CM-I history in asymptomatic patients reveals a favorable evolution.

Early post-operative cerebrospinal fluid hypovolemia: Report of 7 cases

Cerebrospinal fluid (CSF) hypovolemia is a common neurosurgical condition, which may be spontaneous or iatrogenic. At our institution, a substantial number of the reported cases of early post-operative CSF hypovolemia were identified to have unintentional or unrecognized post-operative continuous excessive CSF leakage. Cases who presented with post-operative CSF hypovolemia several days after uneventful intracranial surgeries without continuous CSF leakage were rarely reported. A retrospective review of the medical records of these patients was performed to identify those patients who developed early post-operative CSF hypovolemia without the presence of post-operative continuous CSF leakage. A total of 7 patients, 5 of which were males, were identified in this retrospective study. They experienced CSF hypovolemia between days 1 and 7 after emergency or scheduled intracranial surgeries. Ventricular collapse, cisternal effacement and midline shift are the most common radiological observations. With early diagnosis and management, 4 of the patients achieved a Glasgow Outcome Scale (GOS) score of 5, 1 achieved a GOS score of 4 and the remaining 2 had a GOS score of 3. No mortality was noted in this series. Although rare in incidence, early post-operative CSF hypovolemia may occur without the existence of post-operative continuous CSF leakage. When the diagnosis of CSF hypovolemia is reached, factors that may exacerbate CSF compensation should be promptly terminated. Trendelenburg position and sufficient intravenous hydration are practical and effective managements, and CSF hypovolemia may thereby be reversed in a substantial number of patients.

Acute Foramen Magnum Syndrome Following Single Diagnostic Lumbar Puncture: Consequence of a Small Posterior Fossa?

BACKGROUND

Type I Chiari malformation (CMI) is a rare complication of lumbar cerebrospinal fluid (CSF) drainage that is usually reported after lumbar drain or lumboperitoneal shunt placement. It usually remains asymptomatic; however, even if it becomes symptomatic, symptoms are usually mild. There are only a few reports of acute foramen magnum syndrome following continuous lumbar CSF drainage, and acute foramen magnum syndrome after a single diagnostic lumbar puncture (LP) has not been previously reported. We encountered this catastrophic complication in one of our patient.

CASE DESCRIPTION

A 30-year-old woman with a large supratentorial meningioma and associated asymptomatic CMI presented with holocranial headache. She underwent successful and uneventful excision of the tumor. However, she developed quadriplegia and respiratory arrest 48 hours following a diagnostic LP performed on postoperative day 9. She underwent urgent posterior fossa decompression after magnetic resonance imaging showed increased tonsillar impaction and swelling along with cervicomedullary compression. Postoperatively, she steadily improved and regained normal power after 3 months. Retrospective quantitative analysis of magnetic resonance imaging (MRI) revealed a small posterior fossa.

CONCLUSIONS

The association of intracranial tumors and lumbar CSF drainage with CMI is uncommon. The documentation of a small posterior fossa signifies the importance of both developmental (small posterior fossa) and acquired (intracranial tumor/lumbar CSF drainage) factors in pathogenesis of CMI. Although the extreme rarity of acute deterioration following a single LP does not warrant LP to be contraindicated in such patients, documentation of resolution of CMI with postoperative MRI before performing lumbar CSF drainage (whether therapeutic or diagnostic), might be helpful in avoiding this rare complication.

Cranial nerve palsy secondary to cerebrospinal fluid diversion

OBJECTIVE

Cranial nerve palsy (CNP) secondary to cerebrospinal fluid (CSF) diversion is less familiar to us as a result of its rarity in incidence and insidiousness in presentation. This study aims to further expound the pathophysiological mechanism, clinical presentation, diagnosis, management and prognosis of CNP.

METHODS

From June 2012 to February 2015, 5 of 347 consecutive patients with CNPs secondary to different CSF diversion procedures were treated at our institution. A systematic PubMed search of published studies written in English for patients developing CNPs after CSF diversion procedures from January 1950 to June 2015 was conducted.

RESULTS

Overall, 29 studies and 5 patients of the current series totaling 53 CNPs met the inclusion criteria. CN II, III, IV, V, VI, VII and VIII were got involved in 2 (3.8%), 2 (3.8%), 5 (9.4%), 1 (1.9%), 44 (83.0%), 4 (7.5%) and 1 (1.9%) patients respectively. Thirty-eight patients (71.7%) developed CNPs following inadvertent lumbar puncture, 8 (15.1%) following lumbar drainage, and 7 (13.2%) following ventriculoperitoneal shunt. Forty-eight (90.6%) patients got resolved completely.

CONCLUSIONS

The proposed mechanism of CNP after CSF diversion procedure is CSF hypovolemia and subsequent downward displacement of the brain and traction and distortion of the vascular and peripheral neural structures. As a result of its distinct anatomic characteristics rather than long intracranial course, CN VI is most commonly affected. With early recognition and timely conservative management, most patients could get favorable recovery.

[Cardiac arrest after induction of anesthesia in neurosurgical patients]

The paper reports two clinical cases observed with a time lag of four years. In both cases, there were severe clinical symptoms of intracranial hypertension before the surgery. Prompt full-scale resuscitation was required in both cases due to asystole that developed immediately after induction of anesthesia and tracheal intubation. In one case, cardiac activity was successfully recovered by complex resuscitation with the emergency drainage of the cerebral ventricles. The possible causes of complications and preventive measures were discussed.

Acute tonsillar cerebellar herniation in a patient with traumatic dural tear and VAC therapy after complex trauma

BACKGROUND CONTEXT

Cases of cerebral hypotension and tonsillar herniation after accidental lumbar cerebrospinal fluid (CSF) drainage or chest tube drainage with intrathoracic CSF leaks have been reported. To the authors' knowledge, this case presents the first report of severe intracranial hypotension because of suction of CSF by a Vacuum-Assisted Closure (VAC) device.

PURPOSE

The purpose of this study was to report a life-threatening intracranial hypotension in a polytraumatized patient after VAC therapy.

STUDY DESIGN

This study is a case report.

METHODS

A 23-year-old woman suffered of a Grade 3 open pelvic fracture after a motor vehicle accident. After a VAC therapy, the patient became nonresponsive. A cranial computer tomography (CCT) showed signs of intracranial hypotension with narrowing of the basal cisterns and sagging of the cerebellar tonsils. The VAC was removed. Further neuroradiological diagnostic showed a tear in the dural sac at the L5-S1 level. The patient consequently underwent neurosurgery. After a dural patch, she was oriented postoperatively and the CCT improved to a normal state.

RESULTS

Fifteen days after admission, the patient was discharged without neurologic sequelae.

CONCLUSIONS

Severely injured patients undergoing VAC therapy with secondary neurologic deterioration not because of head injury should be appropriately diagnosed to rule out dural laceration and cranial hypotension.

Upward Translation of Cerebellar Tonsils following Surgical Expansion of Supratentorial Cranial Vault: A Unified Biomechanical Explanation of Chiari Type I

Cerebellar tonsils moved significantly upward in 3 patients with Chiari type I who underwent supratentorial cranial vault expansion to alleviate intracranial pressure related to multisutural craniosynostosis. The Chiari type I deformities in these patients were the biomechanical consequence of posterior fossa-cerebellar disproportion caused by supratentorial craniocerebral disproportion secondary to multisutural craniosynostosis. The authors postulate that all cases of Chiari type I deformity share the sine qua non feature of posterior fossa-cerebellar disproportion.

Cerebral herniation as a complication of chest tube drainage of cerebrospinal fluid after injury to the spine

BACKGROUND

Patients with concomitant injuries to the thorax and thecal sac requiring chest tube drainage are at risk for cerebral herniation caused by overdrainage of cerebrospinal fluid (CSF).

CASE DESCRIPTION

A 40-year-old man presented to the trauma service awake, alert, and oriented with an isolated gunshot wound to the midaxillary line through the tenth intercostal space and a complete spinal cord injury at T12. The patient was stabilized and intubated. A chest tube was placed, and he was transferred to the neurologic intensive care unit. The patient was found to be comatose with complete absence of brainstem reflexes 3 hours after admission.

RESULTS

Magnetic resonance imaging (MRI) and autopsy revealed diffuse cerebral edema, occlusion of the bilateral posterior cerebral arteries, and tonsillar herniation extending several centimeters below the foramen magnum, with petechial hemorrhages and absence of gliosis.

CONCLUSIONS

To the authors' knowledge, this case represents the first report of cerebral herniation secondary to chest tube drainage of a CSF leak caused by traumatic injury to the thecal sac.

Anaesthesia for caesarean section in a patient with Sturge-Weber syndrome following acute neurological deterioration

Sturge-Weber syndrome consists of facial capillary malformation (port-wine stain) and abnormal blood vessels in the brain or eye. Seizures, developmental delay and intracranial and airway angiomata are principal concerns. We report a 28-year-old primiparous woman at 41 weeks of gestation with Sturge-Weber syndrome who developed unilateral weakness, aphasia, blurred vision and confusion. Preeclampsia was excluded. Neuroimaging showed left sided cerebral oedema and a right parieto-occipital lesion, most likely an angioma. Caesarean section was planned to avoid the risk of angioma rupture during labour. General anesthesia was avoided due to the haemodynamic response to laryngoscopy and reports of seizure-related mortality. Despite the possibility of raised intracranial pressure and precipitation of cerebral herniation, a lumbar epidural block was administered but failed. A subarachnoid block was successfully performed and a healthy infant delivered. The choice of anaesthesia was strongly influenced by detailed radiological investigations and multidisciplinary participation.