Chiari I malformation and intra-cranial hypertension:a case-based review

Challenges in the Management of Symptomatic Fallopian Canal Meningoceles: A Multicenter Case Series and Literature Review

OBJECTIVE

To describe the presentations, the diagnosis, our treatment approaches, and the outcomes for 11 patients with fallopian canal meningocele (FCM).

STUDY DESIGN MULTICENTER

Retrospective case series.

SETTING

Tertiary referral centers.

PATIENTS

Patients (N = 11) with radiographically or intraoperatively identified, symptomatic FCM.

INTERVENTIONS

Surgical repair of cerebrospinal fluid (CSF) leak and meningocele versus observation.

MAIN OUTCOME MEASURES

Presentation (including symptoms, radiographic imaging, and comorbidities), management (including surgical approach, technique for packing, use of lumbar drain), clinical outcomes (control of CSF leak, meningitis, facial nerve function), and revision surgery.

RESULTS

Patients presented with spontaneous CSF leak (n = 7), conductive (N = 11) and sensorineural hearing loss (n = 3), nonpositional intermittent vertigo (n = 3), headaches (n = 4), and recurrent meningitis (n = 1). Risk factors in our series included obesity (n = 4), Chiari 1 malformation (n = 1), and head trauma (n = 2). Noncontrast computed tomography of the temporal bone and magnetic resonance imaging were positive for FCM in 10 patients. Eight patients were managed surgically via a transmastoid approach (n = 4), combined transmastoid and middle fossa (N = 3), or middle fossa alone (n = 1); three were managed conservatively with observation. Postoperative complications included worsened facial nerve palsy (n = 1), recurrent meningitis (n = 1), and persistent CSF leak that necessitated revision (n = 1).

CONCLUSIONS

Facial nerve meningoceles are rare with variable presentation, often including CSF otorrhea. Management can be challenging and guided by symptomatology and comorbidities. Risk factors for FCM include obesity and head trauma, and Chiari 1 malformation may present with nonspecific otologic symptoms, in some cases, meningitis and facial palsy. Layered surgical repair leads to high rates of success; however, this may be complicated by worsening facial palsy.

Rapidly progressive medulloblastoma initially mimicking idiopathic intracranial hypertension and Chiari I malformation: A case report

Introduction

Medulloblastoma (MDB) often causes signs and symptoms of elevated intracranial pressure (ICP) with imaging findings of mass lesion. Here, we report a case of MDB who initially presented with clinical features imitating idiopathic intracranial hypertension (IIH) and Chiari I malformation (CIM).

Case presentation

A 19-year-old man had clinical symptoms of elevated ICP without mass lesion on imaging. He was initially diagnosed with IIH and CIM, which underwent shunt surgery and posterior fossa decompression. Later on, he had recurrent symptoms, and the new imaging revealed the development of MDB in the right cerebellar hemisphere. After tumor resection, the patient rapidly deteriorated with spinal metastases.

Discussion and conclusion

Management of the coexistence between IIH and CIM in patients with rising ICP is complicated. MDB is one of the aggressive malignant brain tumors showing a wide range of imaging features, including non-enhancing mass. Therefore, recognizing the possibility of brain tumors mimicking IIH or CIM is crucial.

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The coexistence of idiopathic intracranial hypertension (IIH) and Chiari I malformation (CIM) is complicated.

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Medulloblastoma (MDB) can present with a wide range of imaging features, including non-enhancing mass.

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Exclusion of the secondary cause of rising intracranial pressure is necessary before making the diagnosis of IIH or CIM

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Early diagnosis, including subtype of MDB, and urgent treatment are crucial for better outcome.

Chiari 1 malformation with optic disc drusen

A 32 year old female patient with CM 1 diagnosis was referred for the management of papilledema. Ophthalmologic examination revealed normal visual acuity (20/20 in both eyes), normal optic nerve function tests and normal slit-lamp biomicroscopic findings. Fundoscopy revealed bilateral irregular optic nerve heads with blurred margins. B scan ultrasonography (USG) and Spectral domain optical coherence tomography were performed and bilateral optic nerve heads were diagnosed as ODD. We concluded that the pseudopapilledema must be taken into account before making papilledema diagnosis in patients with CM 1 to protect the patients from redundant interventional procedures.

Diagnostic value of neuro-ophthalmological signs in cases of Chiari I malformation

INTRODUCTION

Our purpose was to evaluate the diagnostic value of measuring diameters of optic nerve sheath (ONSD), presence/absence of papilledema, tortuosity of the optic nerve, flattening of the posterior sclera, and intraocular protrusion of the prelaminar optic nerve for intracranial pressure assessment in cases of Chiari I malformation.

METHODS

In a retrospective study, MRI data of 37 consecutive pediatric patients with Chiari malformation and data of 400 patients without intracranial pathology were compared and analyzed. ONSDs were measured at the point where the ophthalmic artery crosses the optic nerve (anatomical landmark). The correlation analysis was performed with clinical findings, gender, age, papilledema, and other neuro-ophthalmological findings.

RESULTS

ONSD was enlarged in 38 % of cases of Chiari malformation. The enlargement was bilateral, no correlation with age or gender was found (p = 0.67 and p = 0.76, respectively). The presence of papilledema was detected in 19 % of cases presenting less valuable diagnostic sign if compared with ONSD. The tortuosity of the optic nerve was found in 22 % of cases, but in three patients, it was unilateral. All patients with enlarged ONSD and other neuro-ophthalmological signs present were treated surgically, while most of the patients without these signs (20/23) were treated conservatively.

CONCLUSION

In majority of pediatric cases of Chiari malformation, the ONSD is not enlarged and other neuro-ophthalmological signs are not present. Detecting the enlarged ONSD and other neuro-ophthalmological signs in cases of Chiari malformation may indicate the elevated intracranial pressure and necessity for urgent surgical intervention.

[Papillary oedema revealing Arnold Chiari malformation type 1: about a case]

La malformation d'Arnold Chiari de type 1 est définie par une hernie des tonsilles cérébelleuses dans le foramen magnum de plus de 5 mm. Les symptômes sont dominés par les céphalées surtout occipitales, les torticolis, et parfois des troubles de déglutition. Sur le plan ophtalmologique les anomalies de convergences, les paralysies oculomotrices et la diplopie sont les principaux signes cliniques retrouvés. Nous rapportons le cas d'un enfant de 9 ans, qui consulte pour une baisse d'acuité visuelle évoluant depuis 6 mois. L'examen ophtalmologique objective une acuité visuelle chiffrée à 4/10^ème aux deux yeux. Une motilité oculaire conservée ainsi qu'un nystagmus rotatoire. L'examen du segment antérieur montre une mégalocornée, sans goniodysgénésie, un iridodonesis associé à une atrophie du muscle dilatateur, et une microcorie avec un reflex photo-moteur paresseux. Le tonus oculaire est correct à 14 mmHg. Le fond d'œil, malgré la difficulté de le réaliser, objective la présence d'un œdème papillaire bilatéral stade II. L'examen général retrouve un torticolis, une scoliose et un syndrome tétra-pyramidal. L'imagerie par résonance magnétique a mis en évidence une malformation de CHIARI type I, associée à une hydrocéphalie et une syringomyélie. Une intervention neurochirurgicale reposant sur une dérivation interne du LCR avec décompression ostéodurale cervico occipitale est proposée. L'évolution est favorable avec une régression des signes cliniques. Sur le plan ophtalmologique, on note une régression de l'œdème papillaire, mais l'acuité visuelle est restée stationnaire. La survenue d'un œdème papillaire est rare dans la malformation de Chiari type 1, il n'a été décrit que chez 2% des patients symptomatiques. Sa physiopathologie est encore mal élucidée. L'originalité de notre observation consiste en l'association de malformations cérébelleuses avec des malformations oculaires à type de mégalocornée et de microcorie rendant l'examen ophtalmologique encore plus difficile à réaliser.

Comparative observational study on the clinical presentation, intracranial volume measurements, and intracranial pressure scores in patients with either Chiari malformation Type I or idiopathic intracranial hypertension

OBJECTIVE Several lines of evidence suggest common pathophysiological mechanisms in Chiari malformation Type I (CMI) and idiopathic intracranial hypertension (IIH). It has been hypothesized that tonsillar ectopy, a typical finding in CMI, is the result of elevated intracranial pressure (ICP) combined with a developmentally small posterior cranial fossa (PCF). To explore this hypothesis, the authors specifically investigated whether ICP is comparable in CMI and IIH and whether intracranial volumes (ICVs) are different in patients with CMI and IIH, which could explain the tonsillar ectopy in CMI. The authors also examined whether the symptom profile is comparable in these 2 patient groups. METHODS The authors identified all CMI and IIH patients who had undergone overnight diagnostic ICP monitoring during the period from 2002 to 2014 and reviewed their clinical records and radiological examinations. Ventricular CSF volume (VV), PCF volume (PCFV), and total ICV were calculated from initial MRI studies by using volumetric software. The static and pulsatile ICP scores during overnight monitoring were analyzed. Furthermore, the authors included a reference (REF) group consisting of patients who had undergone ICP monitoring due to suspected idiopathic normal-pressure hydrocephalus or chronic daily headache and showed normal pressure values. RESULTS Sixty-six patients with CMI and 41 with IIH were identified, with comparable demographics noted in both groups. The occurrence of some symptoms (headache, nausea, and/or vomiting) was comparable between the cohorts. Dizziness and gait ataxia were significantly more common in patients with CMI, whereas visual symptoms, diplopia, and tinnitus were significantly more frequent in patients with IIH. The cranial volume measurements (VV, PCFV, and ICV) of the CMI and IIH patients were similar. Notably, 7.3% of the IIH patients had tonsillar descent qualifying for diagnosis of CMI (that is, > 5 mm). The extent of tonsillar ectopy was significantly different between the CMI and IIH cohorts (p < 0.001) but also between these 2 cohorts and the REF group. Pulsatile ICP was elevated in both cohorts without any significant between-group differences; however, static ICP was significantly higher (p < 0.001) in the IIH group. CONCLUSIONS This study showed comparable and elevated pulsatile ICP, indicative of impaired intracranial compliance, in both CMI and IIH cohorts, while static ICP was higher in the IIH cohort. The data did not support the hypothesis that reduced PCFV combined with increased ICP causes tonsillar ectopy in CMI. Even though impaired intracranial compliance seems to be a common pathophysiological mechanism behind both conditions, the mechanisms explaining the different clinical and radiological presentations of CMI and IIH remain undefined.

The relationship between obesity and symptomatic Chiari I malformation in the pediatric population

BACKGROUND

Concomitant with the rise in childhood obesity in the United States is an increase in the diagnosis of Chiari I malformation (CM1).

OBJECTIVE

To discern a correlation between obesity and CM1, defined as >5 mm of cerebellar tonsillar descent on sagittal magnetic resonance imaging.

METHODS

Charts of CM1 patients aged 2-20 years were retrospectively reviewed. Chiari size, age, body mass index (BMI), and CM1 signs/symptoms were recorded. Patients were stratified by age: 2-9, 10-14, and 15-20 years. Mixed-effect linear models and linear regression analysis were applied to investigate the relationship between BMI-for-age percentiles and CM1 signs/symptoms.

RESULTS

One hundred sixty-seven patients were included (mean age 14.5 ± 2.97 years, BMI 22.98 ± 6.5, and Chiari size 12.27 mm ± 5.91). When adjusted for age, 42% were overweight or obese-higher than normative BMI for children in the studied area (29.6%). When stratified by age, patients between 2 and 9 years were most commonly obese and presented the highest mean BMI (25.66), largest Chiari size (13.58), and highest incidence of headache (75%) and syringomyelia (66.67%). Patients between 15 and 20 years were most commonly overweight and presented the smallest Chiari size (11.76 mm), but the highest incidence of cerebellar (50%) and brainstem (8.55%) compression symptoms. A significant positive correlation existed between BMI and headache in the first two age groups: (R (2): 0.36, P = 0.03; R (2): 0.39, P = 0.01, respectively). Obese patients had higher incidence of headache in the 10-14 group (R (2): 0.37, P = 0.02) and the largest Chiari size in the 15-20 group (R (2): 0.40, P = 0.03).

CONCLUSIONS

The pediatric CM1 population is more likely to be overweight or obese. Younger obese patients presented the highest incidence of Chiari-related headache symptoms, and older obese patients, the highest incidence of findings other than headache. Thus, body weight and age should be considered when evaluating children with CM1.

Comparison of pulsatile and static pressures within the intracranial and lumbar compartments in patients with Chiari malformation type 1: a prospective observational study

BACKGROUND

In Chiari malformation type 1 (CMI), the obstruction of cerebrospinal fluid (CSF) flow through the foramen magnum is believed to cause alterations of intracranial pressure (ICP) pulsations. Foramen magnum decompression (FMD) is therefore considered a treatment of choice. However, the pathophysiology of CMI is poorly understood and it remains unknown how ICP alterations relate to symptoms and radiological findings. This study was undertaken to measure pulsatile pressure and its gradient between intracranial and lumbar compartments, and to determine its relationship to clinical and radiological findings.

METHOD

In patients with symptomatic CMI, we simultaneously measured ICP and lumbar CSF pressure, with particular focus on analysis of pulsatile pressure. Ventricular CSF volume (VV), intracranial volume (ICV) and posterior cranial fossa volume (PCFV) were calculated using volumetry software.

RESULTS

In 26 patients (median 35 years), we found clearly abnormal or borderline values of pulsatile ICP in 18/26 patients (69 %; median 4.5 mmHg) and abnormal pulsatile pressure gradient in 17/24 patients (71 %; median 2.6 mmHg). The correlation between pulsatile ICP and the pulsatile pressure gradient was significantly positive (p < 0.001). We found no significant correlation between pulsatile or static pressure and extent of tonsillar ectopy, VV, ICV or PCFV. The pulsatile pressure gradient was significantly higher in patients with syringomyelia (p = 0.02).

CONCLUSIONS

In this cohort, the pulsatile ICP was elevated in 69 %. The intracranial-lumbar pulsatile pressure gradient was abnormal in 71 % and significantly higher in patients with syringomyelia. The elevated pulsatile ICP significantly correlated with pulsatile pressure gradient; no similar correlation was found for static ICP. We interpret the results as providing evidence of impaired intracranial compliance as an important pathophysiological mechanism in CMI.

Neuro-ophthalmology of type 1 Chiari malformation

Chiari malformation is a congenital deformity leading to herniation of cerebellar tonsils. Headache is a typical symptom of this condition, but patients with Chiari malformation often present with double vision and vertigo. Examination of eye movements in such patients often reveals nystagmus and strabismus. Eye movement deficits in the context of typical symptomatic presentation are critical clinical markers for the diagnosis of Chiari malformation. We will review eye movement deficits that seen in patients with type 1 Chiari malformation. We will then discuss the underlying pathophysiology and therapeutic options for such deficits.

Impact of body mass index on cerebellar tonsil position in healthy subjects and patients with Chiari malformation

OBJECT

It is unclear if there is a relationship between Chiari malformation Type I (CM-I) and body mass index (BMI). The aim of this study was to identify the relationship between BMI and cerebellar tonsil position in a random sample of people.

METHODS

Cerebellar tonsil position in 2400 subjects from a cohort of patients undergoing MRI was measured. Three hundred patients were randomly selected from each of 8 age groups (from 0 to 80 years). A subject was then excluded if he or she had a posterior fossa mass or previous posterior fossa decompression or if height and weight information within 1 year of MRI was not recorded in the electronic medical record.

RESULTS

There were 1310 subjects (54.6%) with BMI records from within 1 year of the measured scan. Of these subjects, 534 (40.8%) were male and 776 (59.2%) were female. The average BMI of the group was 26.4 kg/m(2), and the average tonsil position was 0.87 mm above the level of the foramen magnum. There were 46 subjects (3.5%) with a tonsil position ≥ 5 mm below the level of the foramen magnum. In the group as a whole, there was no correlation (R(2) = 0.004) between BMI and cerebellar tonsil position.

CONCLUSIONS

In this examination of 1310 subjects undergoing MRI for any reason, there was no relationship between BMI and the level of the cerebellar tonsils or the diagnosis of CM-I on imaging.

Association of increased body mass index with Chiari malformation Type I and syrinx formation in adults

Object

In this paper the authors describe an association between increased body mass index (BMI) and Chiari malformation Type I (CM-I) in adults, as well as its relationship to the development of syringomyelia.

Methods

In the period between January 2004 and December 2011, the senior author reviewed the data for all CM-I patients with or without syringomyelia and neurological deficit. Analyzed factors included clinical status (headaches and neurological signs), radiological characteristics of syringomyelia (diameter and vertical extent of syrinx), BMI, and relationship of age to BMI, syrinx diameter, and vertical extent of syrinx.

Results

Sixty consecutive adults had CM-I, 26 of whom also had syringomyelia. The mean BMI among all patients was 30.35 ± 7.65, which is Class I obesity (WHO), and was similar among patients with or without syringomyelia. Extension of the vertical syrinx was greater in overweight patients (p = 0.027) than in those with a normal body weight. Evidence of de novo syrinx formation was found in 2 patients who gained an average BMI of 10.8 points. After repeated decompression and no change in holocord syrinx width or vertical extent, a reduction in the syrinx was seen after BMI decreased 11.7 points in one individual. No correlation was found between patient age and BMI, age and vertical extension of the syrinx, and age and diameter of the syrinx.

Conclusions

An association between increased BMI and CM-I in adults was recognized. Gaining weight may influence the de novo creation of a syrinx in adults who previously had minimally symptomatic or asymptomatic CM-I, and reducing weight can improve a syrinx after unsuccessful surgical decompression. Therefore, a reduction in body weight should be recommended for all overweight and obese patients with CM-I.

Incidence of cerebellar tonsillar ectopia in idiopathic intracranial hypertension: a mimic of the Chiari I malformation

BACKGROUND AND PURPOSE

IIH is a syndrome of elevated intracranial pressure without hydrocephalus, mass, or identifiable cause. Diagnosis is made by clinical presentation, intracranial pressure measurement, and supportive imaging findings. A subset of patients with IIH may have tonsillar ectopia, meeting the criteria for Chiari malformation type I but not responding to surgical decompression for Chiari I. The purpose of this study was to determine the incidence and morphology of cerebellar tonsillar ectopia in patients with IIH.

MATERIALS AND METHODS

Forty-three patients with clinically confirmed IIH and 44 age-matched controls were included. Two neuroradiologists with CAQs reviewed sagittal T1-weighted MRI in a blinded fashion and measured cerebellar tonsil and obex positions relative to the foramen magnum and prepontine cistern width at the level of the midpons.

RESULTS

Nine of 43 patients with IIH and 1/44 controls had cerebellar tonsillar ectopia of ≥5 mm. Five of 9 of patients with IIH with ectopia of ≥5 mm also had a "peglike" tonsil configuration. Patients with IIH had a significantly lower tonsillar position (2.1 ± 2.8 mm) than age-matched controls (0.7 ±1.9 mm, P < .05). The obex position was significantly lower in patients with IIH versus controls (-7.9 mm [above the FM] versus -9.4 mm [above the FM], P < .05). The prepontine width was not significantly different between the groups.

CONCLUSIONS

Cerebellar tonsil position in patients with IIH was significantly lower than that in age-matched controls, often times peglike, mimicking Chiari I. A significantly lower obex position suggests an inferiorly displaced brain stem and cerebellum. When tonsillar ectopia of >5 mm is identified, imaging and clinical consideration of IIH are warranted to avoid misdiagnosis as Chiari I.

Acute deterioration of a Chiari I malformation: an uncommon neurosurgical emergency

OBJECTIVES

Report and discuss acute neurological deterioration of Chiari I malformation (CMI), surgical treatment and timing, clinical outcome and literature review.

CASE REPORT

We report a recent case of a 15-year-old girl admitted for an acute neurological deterioration caused by an undiagnosed hindbrain herniation that required an urgent foramen magnum decompression and external ventricular drainage insertion. Moreover, we report and discuss the literature. To the authors' knowledge, this is only the third paediatric patient identified in this setting to be treated for an acute neurological deterioration due to a previous asymptomatic hindbrain herniation. The patient made an uncomplicated recovery and was discharged home on the seventh postoperative day and has remained well at review.

DISCUSSION

Acute deterioration of CMI in completely asymptomatic patients in absence of concomitant pathological findings is rarely reported in the literature, and exceptional in children.

CONCLUSIONS

CMI is typically treated electively, but as this case illustrates, it can present with rapidly deteriorating neurological signs. Symptoms usually respond well to surgical intervention with rapid improvement.

Fallopian canal meningocele: report of two cases

OBJECTIVE

The purpose of this study is to report 2 rare cases of congenital fallopian canal meningoceles.

INTERVENTIONS

Magnetic resonance imaging, computed tomography (CT) of the temporal bone, CT-cisternogram, and combined transmastoid approach with middle fossa craniotomy in 2 patients.

MAIN OUTCOME MEASURES

Radiologic and operative diagnosis of congenital fallopian canal meningoceles.

RESULTS

Presentations included spontaneous cerebrospinal fluid (CSF) otorrhea and recurrent meningitis with intracranial hypertension. Postoperative complications included facial nerve palsy and persistent CSF leaks that necessitated ventriculoperitoneal shunt and lumbar drain placement.

CONCLUSION

Use of CT of the temporal bone in combination with CT-cisternogram may define sites of active CSF leak. Intraoperative use of fluorescein may assist identification of cranial base defects to lower rates of recurrence, and intraoperative use of cranial nerve monitoring can minimize the risk of nerve injury during repair.