Diagnosis Of Chiari Research Articles

Evaluation and Treatment of Patients with Small Posterior Cranial Fossa and Chiari Malformation, Types 0 and 1.

The diagnosis of Chiari I malformation is straightforward in patients with typical signs and symptoms of Chiari I malformation and magnetic resonance imaging (MRI) confirming ≥5 mm of cerebellar tonsillar ectopia, with or without a syrinx. However, in many cases, Chiari I malformation is discovered incidentally on MRI to evaluate global headache, cervical radiculopathy, or other conditions. In those cases, the clinician must consider if cerebellar tonsillar ectopia is related to the presenting symptoms. Surgical decompression of the cerebellar tonsils and foramen magnum in patients with symptomatic Chiari I malformation effectively relieves suboccipital headache, reduces syrinx distension, and arrests syringomyelia progression. Neurosurgeons must avoid operative treatments decompressing incidental tonsillar ectopia, not causing symptoms. Such procedures unnecessarily place patients at risk of operative complications and tissue injuries related to surgical exploration. This chapter reviews the typical signs and symptoms of Chiari I malformation and its variant, Chiari 0 malformation, which has <5 mm of cerebellar tonsillar ectopia and is often associated with syringomyelia. Chiari I and Chiari 0 malformations are associated with incomplete occipital bone development, reduced volume and height of the posterior fossa, tonsillar ectopia, and compression of the neural elements and cerebrospinal fluid (CSF) pathways at the foramen magnum. Linear, angular, cross-sectional area, and volume measurements of the posterior fossa, craniocervical junction, and upper cervical spine identify morphometric abnormalities in Chiari I and Chiari 0 malformation patients. Chiari 0 patients respond like Chiari I patients to foramen magnum decompression and should not be excluded from surgical treatment because their tonsillar ectopia is <5 mm. The authors recommend the adoption of diagnostic criteria for Chiari 0 malformation without syringomyelia. This chapter provides updated information and guidance to the physicians managing Chiari I and Chiari 0 malformation patients and neuroscientists interested in Chiari malformations.

Effect of Body Mass Index on Chiari Malformation 1 Tonsil Ectopia Length in Adults

Diagnosis of Chiari I malformation (CM-1) is based on measurements of the inferior extension of the cerebellar tonsils into the foramen magnum on cranial or cervical spine magnetic resonance imaging. Imaging may be obtained before the patient is referred to the neurosurgical specialist. The length of time raises questions about the possibility that body mass index (BMI) fluctuations could affect the measurement of ectopia length. However, previous literature on BMI and CM-1 has reported conflicting findings on BMI. We conducted a retrospective chart review of 161 patients who were referred to a single neurosurgeon for CM-1 consultation. Patients with multiple recorded BMI values (n= 71) were compared to see if BMI changes correlated with changes in ectopia length. In addition, we compared and tested 154 recorded ectopia lengths from the patients (1 per patient) and patient BMI values with Pearson correlation and Welch t tests to determine if BMI changes either influenced or were associated with ectopia changes. For the 71 patients with multiple BMI values, change in ectopia length ranged from-4.6-9.8mm but was not statistically significant (r=0.019; P=0.88). For the 154 measured ectopia lengths, changes in BMI did not correlate with ectopia length (P>0.05). Likewise, differences in ectopia length between patients in normal, overweight, and obese categories were not statistically significant (|tstat|<|tcrit|, P>0.05). In individual patients, we found that BMI and changes in BMI were not accompanied by changes in tonsil ectopia length.

Management of Chiari type I malformation: a retrospective analysis of a series of 91 children treated surgically

The diagnosis of Chiari I malformation, its symptomatology, and the results of its surgical management are still discussed. We report a pediatric series of CMI without associated skull base malformations or cerebellar growth anomalies operated between 2001 and 2018. Ninety-one children out of 146 surgically treated cases have been included in the study. Age at surgery ranged from 5months to 17years clinical data, and complementary examinations leading to the surgical indication have been analyzed together with the surgical outcomes. The average follow-up duration was of 4years. The occipito-cervical decompression with duraplasty without opening the arachnoid was the procedure of election. Three quarters of patients presented with headaches, 12% with cerebellar syndrome, 13% with vertigo, 26% with nausea or vomiting, 24% with sensorimotor deficits, 11% with cranial nerve deficits, and 29% with other symptoms. Eighteen percent of patients suffered from scoliosis, 47% had an associated syrinx and 16% a ventricular dilation. After the treatment, the clinical symptomatology improved in about three-quarters of the patients: headache (69.4%), nausea or vomiting (66.7%), sensorimotor deficits (55.6%), and other symptoms (78.3%). Syringomyelic cavities diminished partially in size or disappeared in 58.3% of patients, remained stable in 29.2%, and worsened in 12.5%. Only one-third of children with preoperative scoliosis benefited from the surgical treatment. No clinical signs or symptoms were found to be reliable predictors of surgical success, neither the extent of the cerebellar tonsil descent. Occipito-cervical decompression allows to improve the clinical condition in the majority of children with symptomatic CMI in the absence of associated cervico-spinal junction alterations, craniosynostosis, or cerebellar growth anomalies. No clinical signs or symptoms neither radiological criterion appear to be a specific finding for the surgical indication.

Preoperative Acetazolamide Challenge in Pediatric Chiari I Malformation

Purpose: In patients who present with headaches and Chiari 1 malformation without cranial nerve or brainstem dysfunction or syrinx formation, the decision to decompress can be difficult to make. We present a case series examining the use of acetazolamide as a diagnostic aid to determine candidacy for decompression. Methods: A single pediatric neurosurgeon’s (M.M.H.) experience from 2003 to 2018 was retrospectively reviewed. All cases evaluated in the clinic for CPT code of Chiari 1 malformation were analyzed. Inclusion criteria were patients with diagnosis of Chiari 1 malformation and headache-predominant symptoms who underwent an acetazolamide challenge test. Exclusion criteria included age over 18, syrinx, or significant clinical evidence of brainstem compression or cranial nerve dysfunction. Data were recorded with respect to response to acetazolamide. Surgical outcomes were assessed using the Chicago Chiari Outcome Scale (CCOS) pain category and the improve/same/worse (IWS) scale. Overall satisfaction from surgery was also recorded. Results: Forty-five patients met inclusion criteria and underwent acetazolamide challenge. Thirty-three (73.3%) patients showed improvement of their symptoms with acetazolamide challenge (responders). Of the 33 responders, 25 (75.8%) underwent Chiari decompression. The remaining 8 (24.2%) responders experienced persistent improvement of their symptoms after the acetazolamide trial and did not require intervention. Twelve (26.7%) patients did not improve with acetazolamide (nonresponders) of which 11 (91.7% of nonreponders) never required intervention. One nonresponder eventually underwent Chiari decompression due to progressively worsening and debilitating headaches. All twenty-five (100%) responders improved after surgery and 24 (96%) were satisfied with the outcome of surgery. The average responder CCOS pain score was 3.52 out of 4. The nonresponder who did not improve with acetazolamide had persistent severe headaches after decompression. The CCOS pain score for this nonresponder was 2 out of 4. Conclusion: Pediatric headache-predominant Chiari 1 malformation presents a difficult diagnostic dilemma. The authors describe a trial of acetazolamide as a preoperative diagnostic tool to aid the decision to decompress. Further studies will need to be performed to determine the effectiveness of preoperative acetazolamide in identifying which patients may benefit from surgical decompression.

Modern approaches and diagnostic tools in neurosurgical practice: a case of patient with intracranial hypotension and secondary cervical spine degeneration

We report a case of a 47-years old woman presented to our department with the diagnosis of Chiari I malformation and extensive hydrosyringomyelia. Her main complains were severe headache and chronic pain syndrome in the left side of her breast and left arm. Magnetic resonance imaging (MRI) showed alterations suggestive of the presence of intracranial hypotension (IH), that was confirmed by measurement of cerebrospinal fluid (CSF) opening pressure and then CSF venous fistula was detected by computed tomography myelography (CTM). She was successfully surgically treated which leaded to the regression of the clinical symptoms and radiological alterations. Nevertheless, during her recovery after surgery she had an episode of recurrent left arm pain, which was interpreted as secondary cervical spine degeneration consequence. MRI confirmed C5-C6 disc herniation and transforaminal epidural injection of local anesthetic and corticosteroid solutions was performed. A week later she already felt significant improvement as her pain syndrome regressed a lot. IH should be considered in the differential diagnosis of headache and sagging brainstem and tonsils with cord syrinx on MRI and should not be misinterpreted as Chiari malformation. At the same time, transforaminal epidural injection appears to be an effective tool in modern neurosurgical practice allowing to determine the reason and accurate radiculopathy level.

Operative findings and surgical outcomes in patients undergoing Chiari 1 malformation decompression: relationship to the extent of tonsillar ectopia.

The diagnosis of Chiari 1 malformation is based on the extent of tonsillar ectopia. To examine the relationship between the extent of tonsillar ectopia and the intra-operative findings and clinical outcome following Chiari decompression surgery. Patients were divided into four groups depending on the position of the cerebellar tonsil (T): group 1: 0 < T < 3; group 2: 3 ≤ T ≤ 5; group 3: 5 < T ≤ 10; and group 4: T > 10. Intra-operative observations were recorded with regard to compression of the brain stem by posterior inferior cerebellar artery (pica), neuroma formation along the first cervical (C1), and accessory spinal nerves (XI), and pallor of the cerebellar tonsils. Brain stem auditory evoked potentials, (BAEP), were monitored in each case. One hundred sixty-eight patients accrued between 2009 and 2013 agreed to participate in an outcome study to determine the effectiveness of foramen magnum decompression. Findings across the four groups were compared using one-way ANOVA. Observed differences were further subjected to paired analysis. Intra-group comparisons were made using the paired t test. A P value less than 0.05 was considered statistically significant. There were 98 patients in group 1, 147 patients in group 2, 180 patients in group 3, and 63 patients in group 4. The mean extent of tonsillar ectopia was 0.4, 4.0, 7.1, and 14.3mm in the four groups respectively. The prevalence of tonsillar pallor was greatest in group 4. Otherwise, there was no difference observed in the operative findings. A reduction of > 0.1msec in the wave III-wave V latency of the BAEP was noted in all four groups with equal frequency. One hundred ten patients complied with at least 6months follow-up. There was no difference in the prevalence of symptoms between the four groups at the time of initial evaluation and at 6weeks and 6months following surgery. There was a statistically significant reduction in the intensity of individual symptoms 6months following surgery regardless of the extent of tonsil ectopia. Other than the finding of tonsillar pallor, there was no relationship between the extent of tonsillar ectopia and the intraoperative anatomical and physiological observations, nor was there any relationship to the likelihood of symptomatic improvement following surgery. These observations call into question the focus on the extent of tonsillar of ectopia in assessing the patient who presents with symptoms of the Chiari malformation.

Chiari Malformation Type 1 as Cause of Recurrent Pneumonia with Failure to Thrive

Diagnosing the cause of recurrent pneumonia with failure to thrive (FTT) can be difficult. A nine months age presented with recurrent pneumonia and failure to thrive. Investigation for the same led to the diagnosis of Chiari 1 malformation. Screening for latent neurological disorders should be done in such patients.J Nepal Paediatr Soc 2016;36(3):288-290

Chiari I malformation as part of the Floating-Harbor syndrome?

We report the first case of a patient diagnosed with Floating-Harbor syndrome (FHS) and Chiari I malformation. The 3-year-old girl was of proportional short stature, had delay of language development, conductive hearing loss and a high threshold of pain. Diagnosis of Chiari I malformation may be difficult in FHS patients who present with communication problems. Clinicians following patients with FHS should be aware of a possible relation between FHS and Chiari I malformation.

The Role of Cine Flow Magnetic Resonance Imaging in Patients with Chiari 0 Malformation.

To define the role of phase-contrast cine magnetic resonance imaging (MRI) in deciding the therapeutic strategy and underlying pathophysiology resulting in syrinx formation in patients with Chiari type 0 malformation. Seven patients who were admitted to our clinic with the diagnosis of Chiari 0 malformation from January 2005 to July 2016 were enrolled in the study. All patients underwent a detailed preoperative neurological examination. Entire neuroaxis MRI and phase-contrast cine MRI were obtained preoperatively and postoperatively. Seven patients (5 female and 2 male) with Chiari type 0 malformation fulfilled the inclusion criteria. All of the patients had absent cine flow at the craniovertebral junction except two patients. These five patients underwent surgical interventions; suboccipital decompression and duraplasty. All of them showed both clinical and radiological improvement in the postoperative period. Cine flow MRI appears to be a useful tool in the management of patients with Chiari 0 malformation. There was a good correlation between the clinical presentation and cine flow preoperatively, and between clinical improvement and cine flow in the postoperative period.

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: (R2: 0.36, P = 0.03; R2: 0.39, P = 0.01, respectively). Obese patients had higher incidence of headache in the 10–14 group (R2: 0.37, P = 0.02) and the largest Chiari size in the 15–20 group (R2: 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.

Hidden aqueductal stenosis associated to bilateral idiopathic foramina of Monro stenosis mimicking a Chiari I malformation? Case report

A 39-year old man came to our outpatient clinic with long history of unspecific symptoms and signs. Cerebral MRI showed herniation of the cerebellar tonsils of more than 1cm below the foramen magnum and a triventricular hydrocephalus. A diagnosis of Chiari I malformation was retained. After an osteo-dural decompression of the posterior fossa, post-operative MRI revealed an aqueductal stenosis with triventricular hydrocephalus. An endoscopic-third- ventriculostomy showed an idiopathic stenosis of the right foramen of Monro. Residual symptoms and persistence of biventricular hydrocephalus justified a ventriculo-peritoneal shunt. Aqueductal and foramina of Monro stenosis can mimick a Chiari I malformation.

Prenatal Diagnosis of Chiari III Malformation by 2D and 3D Sonography

Chiari III malformation is the most rare and severe form of the four types of Chiari malformations. It is characterized by a high cervical meningoencephalocele and caudal displacement of the cerebellum and brainstem. The encephalocele may contain cerebellum, brainstem, cerebrospinal fluid, and rarely the occipital lobe. This case describes a fetus with a large posterior occipitocervical encephalocele diagnosed by sonography at 21 weeks' gestation. We believe this is the first reported Chiari III malformation diagnosed prenatally by sonography alone, as well as the first to describe the diagnosis using 3D sonography.

Sensorineural Hearing Impairment in Children with Chiari I Malformation

We describe the prevalance of Chiari I malformation in children presenting to a pediatric tertiary care hearing loss clinic, characterize the phenotype of hearing loss in children with Chiari I malformation, and discuss the potential pathophysiology of sensorineural hearing impairment (SNHI) related to Chiari I malformation. This study was a retrospective case series of patients seen in a pediatric tertiary care hearing loss clinic affiliated with an academic medical center. We considered 481 patients with SNHI who had radiographic imaging as part of the evaluation for the cause of their hearing impairment. Hearing impairment was determined by behavioral audiogram and/or auditory brain stem response testing. Radiographic imaging was performed with computed tomography and/or magnetic resonance imaging. Six children with SNHI also had a diagnosis of Chiari I malformation. Four of these 6 children had unilateral hearing impairment. One child had asymmetric bilateral impairment; 1 child had symmetric bilateral impairment. The severity of hearing impairment varied from mild to profound. All children were referred to the neurosurgery department. None underwent surgical decompression. Chiari I malformation may be associated with SNHI. Central nervous system imaging for the evaluation of children with SNHI may be indicated, particularly in individuals with negative results on temporal bone computed tomography and genetic testing.

Dilated Fourth Ventricle on Brain Computed Tomography Scan in the Diagnosis of Chiari I Malformation with Syringomyelia

Dilated Fourth Ventricle on Brain Computed Tomography Scan in the Diagnosis of Chiari I Malformation with Syringomyelia

P38.06: Prenatal diagnosis of Chiari III malformation: do not confuse with anencephaly

P38.06: Prenatal diagnosis of Chiari III malformation: do not confuse with anencephaly

Diagnosis of Chiari I malformation and related syringomyelia: radiological and neurophysiological studies.

The diagnosis of Chiari I malformation relies mainly on the anatomical demonstration of the abnormal position of the cerebellar tonsils below the foramen magnum, and of the associated bony anomalies of the posterior cranial fossa and craniocervical junction, as well as of the eventually-associated spinal cord cavitations. Consequently, the neuroradiological work-up plays a fundamental role in the definition of the malformation and in the follow-up of operated patients. The authors review the pertinent literature on the neuroradiology of the Chiari I malformation, with special regard to MRI, with the aim of providing the reader with an updated instrument for its diagnosis.

Clinical features of Chiari I malformations.

With the advent of MRI, the diagnosis of Chiari I malformation is being made in younger patients, often with minimal or no neurologic symptoms. The symptoms and signs of a Chiari I malformation may be related to the compression of neural and/or dural structures at the cranio-cervical junction or may be related to the associated syringomyelia. Scoliosis is a particularly important and common finding in those children with syringomyelia.

Chiari I malformation in parturients

Study Objective: To assess complications of regional as well as general anesthesia in parturients with Chiari I malformation. Design: Retrospective chart review Setting: Academic medical center Patients: All parturients in our institution who had the diagnosis of Chiari I malformation and delivered in our hospitals over a 50-year period. Main Results: 12 parturients delivered 30 babies. Three deliveries were facilitated with general anesthesia. Nine deliveries were facilitated with central axis anesthesia, six with epidural anesthesia, two with a single injection of a spinal anesthetic, and one with a continuous spinal catheter. The patient who received a continuous spinal catheter developed a postdural puncture headache that resolved with an epidural blood patch. None of the patients who received general, spinal, or epidural anesthesia for their deliveries developed symptoms or had exacerbation of preexisting symptoms of Chiari I malformation. Conclusions: General anesthesia, as well as spinal and epidural anesthesia, appeared to be safe and effective in our series of vaginal or cesarean delivery patients. The small number of patients in our series does not negate the cautious recommendations of others, but suggests that general anesthesia, as well as spinal or epidural anesthesia, can be used safely and effectively in these patients.

Complete Spontaneous Resolution of Childhood Chiari I Malformation and Associated Syringomyelia

The diagnosis of Chiari I malformation and associated syringomyelia is often made in childhood. Since the advent of magnetic resonance imaging, these abnormalities are increasingly detected incidentally. Despite incomplete understanding of the natural history of asymptomatic Chiari I malformations, the current recommendation is to consider prophylactic surgical intervention in those with an associated syringomyelia. This case report presents a complete spontaneous resolution of a Chiari I malformation and syringomyelia in a child. It illustrates the possibility that asymptomatic children with Chiari I malformations and syringomyelia may be followed conservatively.