The natural history of the Chiari Type I anomaly

2008 ◽  
Vol 2 (3) ◽  
pp. 179-187 ◽  
Author(s):  
Federica Novegno ◽  
Massimo Caldarelli ◽  
Antonio Massa ◽  
Daniela Chieffo ◽  
Luca Massimi ◽  
...  
Keyword(s):  
Mr Imaging ◽  
Chiari Malformation ◽  
Clinical Signs ◽  
Type I ◽  
Conservative Approach ◽  
Tonsillar Herniation ◽  
Chiari Malformation Type I ◽  
Lack Of Information ◽  
Mild Reduction

Object Since the advent of MR imaging, an increasing number of asymptomatic or oligosymptomatic patients have been diagnosed with Chiari malformation Type I (CM-I). The decision of whether or not to operate is more difficult in these patients than in those with clear symptoms because of the lack of information about the natural course of this disease. Methods The authors report on their experience in a series of 22 patients with CM-I who were evaluated at the authors' institution, and for whom a conservative approach to treatment was adopted. The patients ranged in age from 1 to 16 years (mean 6.3 years) at diagnosis. Neuroradiological and complete clinical examinations were performed in all patients 6 months after the first observation and every year thereafter. The follow-up period ranged from 3 to 19 years (mean 5.9 years). Results Chiari malformation Type I was incidentally detected on MR images in 11 of 22 patients. The remaining 11 patients had minimal clinical signs at presentation that were not regarded as necessitating immediate surgical treatment. Seventeen patients (77.3%) showed progressive improvement in their symptoms or remained asymptomatic at the last follow-up whereas 5 patients (22.7%) experienced worsening, which was mild in 2 cases and required surgical correction in the remaining 3 cases. On MR imaging a mild reduction in tonsillar herniation was appreciated in 4 patients (18.18%), with complete spontaneous resolution in 1 of these. In 16 patients, tonsillar herniation remained stable during follow-up. Conclusions The authors' data confirm the common impression that in both asymptomatic and slightly symptomatic patients with CM-I, a conservative approach to treatment should be adopted with periodic clinical and radiological examinations.

Chiari malformation Type I and syrinx in children undergoing magnetic resonance imaging

2011 ◽  
Vol 8 (2) ◽  
pp. 205-213 ◽  
Author(s):  
Jennifer Strahle ◽  
Karin M. Muraszko ◽  
Joseph Kapurch ◽  
J. Rajiv Bapuraj ◽  
Hugh J. L. Garton ◽  
...  
Keyword(s):  
Cervical Spine ◽  
Mr Imaging ◽  
Chiari Malformation ◽  
Foramen Magnum ◽  
Type I ◽  
Csf Flow ◽  
Tonsillar Herniation ◽  
Chiari Malformation Type I ◽  
Age Related ◽  
Imaging Characteristics

Object Chiari malformation Type I (CM-I) with an associated spinal syrinx is a common pediatric diagnosis. A better understanding of the relative age-related prevalence and MR imaging characteristics of these associated conditions may lead to improved treatment decisions. Methods The authors performed a retrospective review of 14,116 consecutive individuals 18 years of age or younger who had undergone brain or cervical spine MR imaging at the University of Michigan between November 1997 and August 2008. In the patients with CM-I, demographic, clinical, and radiographic information was recorded. Results Five hundred nine children (3.6%) with CM-I were identified. Among these patients, 23% also had a spinal cord syrinx, and 86% of the syringes were found in the cervical spine. The MR imaging prevalence of CM-I with a syrinx was 1.2% in girls and 0.5% in boys (p < 0.0001). The severity of impaired CSF flow at the foramen magnum was associated with the amount of tonsillar herniation (p < 0.0001) and conformation of the tonsils (p < 0.0001). Patients with CM-I were treated surgically in 35% of cases; these patients exhibited more severe tonsillar herniation (p < 0.0001) and impaired CSF flow (p < 0.0001) as compared with those who did not undergo surgery. On imaging, 32% of all the patients with CM-I were considered symptomatic by the treating physician. Patients were more likely to be considered symptomatic if they were female, had a syrinx, displayed abnormal tonsillar pulsations, or had a greater amount of tonsillar herniation. Conclusions In this study the authors describe the age-related prevalence and MR imaging characteristics of CM-I and its association with a syrinx and other abnormalities in a large group of children who underwent MR imaging for any indication. Syringes are more common in older children, in girls, and in patients with a greater degree of tonsillar descent and CSF flow impairment.

Prognostic significance of C1–C2 facet malalignment after surgical decompression in adult Chiari malformation type I: a pilot study based on the Chicago Chiari Outcome Scale

2020 ◽  
pp. 1-7
Author(s):  
Michael Lumintang Loe ◽  
Tito Vivas-Buitrago ◽  
Ricardo A. Domingo ◽  
Johan Heemskerk ◽  
Shashwat Tripathi ◽  
...  
Keyword(s):  
Pilot Study ◽  
Chiari Malformation ◽  
Prognostic Significance ◽  
Foramen Magnum ◽  
Bivariate Analysis ◽  
Type I ◽  
Foramen Magnum Decompression ◽  
Swallowing Function ◽  
Chiari Malformation Type I

OBJECTIVEThe authors assessed the prognostic significance of various clinical and radiographic characteristics, including C1–C2 facet malalignment, in terms of surgical outcomes after foramen magnum decompression of adult Chiari malformation type I.METHODSThe electronic medical records of 273 symptomatic patients with Chiari malformation type I who were treated with foramen magnum decompression, C1 laminectomy, and duraplasty at Mayo Clinic were retrospectively reviewed. Preoperative and postoperative Neurological Scoring System scores were compared using the Friedman test. Bivariate analysis was conducted to identify the preoperative variables that correlated with the patient Chicago Chiari Outcome Scale (CCOS) scores. Multiple linear regression analysis was subsequently performed using the variables with p < 0.05 on the bivariate analysis to check for independent associations with the outcome measures. Statistical software SPSS version 25.0 was used for the data analysis. Significance was defined as p < 0.05 for all analyses.RESULTSFifty-two adult patients with preoperative clinical and radiological data and a minimum follow-up of 12 months were included. Motor deficits, syrinx, and C1–C2 facet malalignment were found to have significant negative associations with the CCOS score at the 1- to 3-month follow-up (p < 0.05), while at the 9- to 12-month follow-up only swallowing function and C1–C2 facet malalignment were significantly associated with the CCOS score (p < 0.05). Multivariate analysis showed that syrinx presence and C1–C2 facet malalignment were independently associated with the CCOS score at the 1- to 3-month follow-up. Swallowing function and C1–C2 facet malalignment were found to be independently associated with the CCOS score at the 9- to 12-month follow-up.CONCLUSIONSThe observed results in this pilot study suggest a significant negative correlation between C1–C2 facet malalignment and clinical outcomes evaluated by the CCOS score at 1–3 months and 9–12 months postoperatively. Prospective studies are needed to further validate the prognostic value of C1–C2 facet malalignment and the potential role of atlantoaxial fixation as part of the treatment.

scholarly journals Standard and cardiac-gated phase-contrast magnetic resonance imaging in the clinical course of patients with Chiari malformation Type I

2011 ◽  
Vol 31 (3) ◽  
pp. E5 ◽  
Author(s):  
Uwe Max Mauer ◽  
Andreas Gottschalk ◽  
Carolin Mueller ◽  
Linda Weselek ◽  
Ulrich Kunz ◽  
...  
Keyword(s):  
Mr Imaging ◽  
Chiari Malformation ◽  
Phase Contrast ◽  
Foramen Magnum ◽  
Central Canal ◽  
Type I ◽  
Csf Flow ◽  
Chiari Malformation Type I ◽  
Cerebrospinal Fluid Flow ◽  
Contrast Magnetic Resonance

Object The causal treatment of Chiari malformation Type I (CM-I) consists of removing the obstruction of CSF flow at the level of the foramen magnum. Cerebrospinal fluid flow can be visualized using dynamic phase-contrast MR imaging. Because there is only a paucity of studies evaluating CSF dynamics in the region of the spinal canal on the basis of preoperative and postoperative measurements, the authors investigated the clinical usefulness of cardiacgated phase-contrast MR imaging in patients with CM-I. Methods Ninety patients with CM-I underwent preoperative MR imaging of CSF pulsation. Syringomyelia was present in 59 patients and absent in 31 patients. Phase-contrast MR imaging of the entire CNS was used to investigate 22 patients with CM-I before surgery and after a mean postoperative period of 12 months (median 12 months, range 3–33 months). In addition to the dynamic studies, absolute flow velocities, the extension of the syrinx, and tonsillar descent were also measured. Results The changes in pulsation were highly significant in the region of the (enlarged) cistern (p = 0.0005). Maximum and minimum velocities (the pulsation amplitude) increased considerably in the region where the syrinx was largest in diameter. The changes of pulsation in these patients were significant in the subarachnoid space in all spinal segments but not in the syrinx itself and in the central canal. Conclusions The demonstration of CSF flow pulsation can contribute to assessments of surgical outcomes. The results presented here, however, raise doubts about current theories on the pathogenesis of syringomyelia.

Sudden onset of Chiari malformation Type I in previously asymptomatic patients

2011 ◽  
Vol 8 (5) ◽  
pp. 438-442 ◽  
Author(s):  
Luca Massimi ◽  
Giuseppe Maria Della Pepa ◽  
Gianpiero Tamburrini ◽  
Concezio Di Rocco
Keyword(s):  
Chiari Malformation ◽  
Clinical Presentation ◽  
Clinical Signs ◽  
Abrupt Onset ◽  
Sudden Onset ◽  
Neck Injury ◽  
Type I ◽  
Chiari Malformation Type I ◽  
Clinical Onset ◽  
Asymptomatic Patients

Chiari malformation Type I (CM-I) is usually suspected in patients with slowly progressing neurological symptoms. However, in some instances, especially if syringomyelia is associated, an abrupt clinical onset is reported and is accompanied by an acknowledged risk of potentially severe clinical signs or even sudden death. Little is known about such a critical course in CM-I/syringomyelia complex. The authors describe 3 challenging cases of the abrupt onset of CM-I/syringomyelia to reveal more information on the clinical presentation and pathogenetic mechanisms of this sudden and potentially severe clinical phenomenon: a 38-year-old man experienced acute respiratory failure requiring intubation following acute decompensation of hydrocephalus associated with Noonan syndrome, a 1-year-old boy had sudden hemiparesis and Horner syndrome after a minor head/neck injury, and a 2.5-year-old boy presented with quickly progressing tetraplegia and dyspnea after a mild flexion and extension neck injury a few hours before. All 3 patients showed a CM-I/syringomyelia complex at diagnosis, and all of them had a good neurological outcome after surgery despite the ominous clinical presentation.

Reversible tonsillar prolapse and syringomyelia after embolization of a tectal arteriovenous malformation

2007 ◽  
Vol 107 (2) ◽  
pp. 412-415 ◽  
Author(s):  
Georges Rodesch ◽  
Bernard Otto ◽  
Micheline Mouchamps ◽  
Jacques Born
Keyword(s):  
Magnetic Resonance ◽  
Mr Imaging ◽  
Arteriovenous Malformation ◽  
Chiari Malformation ◽  
Clinical Symptoms ◽  
Type I ◽  
Imaging Findings ◽  
Mr Image ◽  
Chiari Malformation Type I ◽  
Straight Sinus

✓ The authors report the case of a 21-year-old woman who presented with headaches, frequent sensations of loss of equilibrium, and intermittent strabismus. A tectal arteriovenous malformation (AVM) was diagnosed based on magnetic resonance (MR) imaging findings. The AVM drained toward the straight sinus and was associated with a tonsillar prolapse (Chiari malformation Type I [CM-I]) and cervical syringomyelia. The tectal AVM was embolized with N-butyl cyanoacrylate, and disconnection of about 80% of the lesion was obtained. All clinical symptoms resolved after embolization, and radiosurgery was proposed to treat the malformation remnant. A control MR image confirmed the regression of the tonsillar prolapse and the disappearance of the syrinx. This report emphasizes that CM-I and syringomyelia may be acquired and related to hydrovenous disorders.

Scoliosis and Chiari malformation Type I in children

2011 ◽  
Vol 7 (1) ◽  
pp. 25-29 ◽  
Author(s):  
Mark D. Krieger ◽  
Yuri Falkinstein ◽  
Ira E. Bowen ◽  
Vernon T. Tolo ◽  
J. Gordon McComb
Keyword(s):  
Mr Imaging ◽  
Spinal Instrumentation ◽  
Magnetic Resonance Images ◽  
Type I ◽  
Chiari Malformation Type I ◽  
Adequate Treatment ◽  
Fusion Surgery ◽  
Spinal Fusion Surgery ◽  
Curve Magnitude

Object The identification of Chiari malformations Type I (CM-Is) has increased in recent years, commonly during MR imaging for evaluation of a possible cause of scoliosis. The treatment of this abnormality remains controversial, and the expected success of treatment is unclear. The goal of the present study is to evaluate the effects of a craniotomy for CM-I decompression on scoliosis in children and adolescents. Methods The authors conducted a 10-year retrospective review of pediatric patients who were found to have a CM-I during evaluation for scoliosis. Seventy-nine patients were identified, ranging in age from 6 months to 18 years (median 12 years). There were 42 girls (54%) and 37 boys (46%). All were noted on MR imaging to have hydrosyringomyelia of the spinal cord. Forty-nine patients had curvatures less than 20° prior to treatment. The other 30 patients had curves ranging from 25° to 80° and underwent orthopedic follow-up and treatment. None of these patients were referred for specific neurological complaints, but 12 (16%) had neurological signs on physical examination. All were treated with a craniocervical decompression in a standard fashion. Follow-up ranged from 6 to 93 months with a median of 35 months. Magnetic resonance images obtained at 6 months postoperatively and serial standing anteroposterior spine radiographs were used to evaluate outcomes. Results On the MR images obtained 6 months postoperatively, 70 patients (89%) had a significant reduction in the syrinx with an associated ascent of the cerebellar tonsils. Persistent large syringes were treated with reoperation in 6 patients, and shunts were inserted for hydrocephalus in 2 patients. None of the 49 patients with curves less than 20° had progression of their curvature postoperatively. Of the 30 patients with curves greater than 25°, 9 had no change in the scoliosis or had a reduction in curve magnitude after Chiari decompression. This group required no further therapy and was effectively treated by Chiari decompression alone. Twenty-one patients required further scoliosis treatment after Chiari decompression; 12 required orthotic treatment, 11 received spinal instrumentation and fusion surgery, and 2 received orthoses followed by fusion and instrumentation. The severity of the curvature beyond 20° did not predict the need for spinal surgery. Conclusions This large series reports on the efficacy of treatment for scoliosis associated with a CM-I and syrinx in children. A CM-I decompression alone was adequate treatment for mild scoliosis of less than 20°. Patients with scoliosis greater than 20° required bracing and/or spinal fusion surgery 70% of the time in addition to the CM-I decompression.

Intracranial hypertension in 2 cases of craniometaphyseal dysplasia: differing surgical options

2011 ◽  
Vol 31 (2) ◽  
pp. E6 ◽  
Author(s):  
Mónica Rivero-Garvía ◽  
F. Javier Márquez-Rivas ◽  
Antonia García-Iglesias ◽  
Raquel Gutiérrez-González
Keyword(s):  
Mr Imaging ◽  
Intracranial Hypertension ◽  
Chiari Malformation ◽  
Type I ◽  
Chiari Malformation Type I ◽  
Decompressive Craniotomy ◽  
Csf Shunting ◽  
Surgical Options ◽  
Exon 9 ◽  
Craniometaphyseal Dysplasia

Craniometaphyseal dysplasia (CMD) is a very rare bone disorder characterized by abnormally developed metaphyses in long bones and sclerosis of the craniofacial bones. In this paper, the authors report 2 cases of children diagnosed with CMD and chronic intracranial hypertension with deletion in exon 9 of the human ANK gene (ANKH). After intracranial monitoring, a different treatment was chosen for each patient. One of the patients was treated using CSF shunting because ventriculomegaly in the absence of a Chiari malformation was also observed on cerebral MR imaging. The other patient underwent cranial expansion and decompressive craniotomy of the posterior fossa, because ventriculomegaly was excluded after cerebral MR imaging and cervical MR imaging showed a Chiari malformation Type I. The origin of intracranial hypertension in CMD is multifactorial. Previous intracranial pressure monitoring and a thorough understanding of neuroimaging studies are essential to achieve an accurate diagnosis and effective treatment.

Nonoperative management of enlarging syringomyelia in clinically stable patients after decompression of Chiari malformation type I

2021 ◽  
Vol 28 (1) ◽  
pp. 28-33
Author(s):  
Nicholas S. Szuflita ◽  
Tiffany N. Phan ◽  
Jason H. Boulter ◽  
Robert F. Keating ◽  
John S. Myseros
Keyword(s):  
Chiari Malformation ◽  
Nonoperative Management ◽  
Posterior Fossa Decompression ◽  
Type I ◽  
Chiari Malformation Type I ◽  
Suboccipital Craniectomy ◽  
Close Observation ◽  
Lost To Follow Up ◽  
Serial Mri

OBJECTIVE The authors aimed to describe the natural history and optimal management of persistent syringomyelia after suboccipital craniectomy for Chiari malformation type I (CM-I). METHODS A cohort of all patients who presented to a tertiary pediatric hospital with newly diagnosed CM-I between 2009 and 2017 was identified. Patients with persistent or worsened syringomyelia were identified on the basis of a retrospective review of medical records and imaging studies. The management of these patients and their clinical courses were then described. RESULTS A total of 153 children with CM-I and syringomyelia were evaluated between 2009 and 2017. Of these, 115 (68.8%) patients underwent surgical intervention: 40 patients underwent posterior fossa decompression (PFD) alone, 43 underwent PFD with duraplasty, and 32 underwent PFD with duraplasty and fourth ventricle stent placement. Eleven (7.19%) patients had increased syringomyelia on subsequent postoperative imaging. Three of these patients underwent revision surgery because of worsening scoliosis or pain, 2 of whom were lost to follow-up, and 4 were managed nonoperatively with close surveillance and serial MRI evaluations. The syringes decreased in size in 3 patients and resolved completely in 1 patient. CONCLUSIONS Persistent or worsened syringomyelia after CM-I decompression is uncommon. In the absence of symptoms, nonoperative management with close observation is safe for patients with persistent syrinx.

Natural history of Chiari malformation Type I following decision for conservative treatment

2011 ◽  
Vol 8 (2) ◽  
pp. 214-221 ◽  
Author(s):  
Jennifer Strahle ◽  
Karin M. Muraszko ◽  
Joseph Kapurch ◽  
J. Rajiv Bapuraj ◽  
Hugh J. L. Garton ◽  
...  
Keyword(s):  
Natural History ◽  
Mr Imaging ◽  
Foramen Magnum ◽  
Type I ◽  
Csf Flow ◽  
Chiari Malformation Type I ◽  
Nonsurgical Management ◽  
Cerebellar Tonsillar Herniation ◽  
History Of

Object The natural history of the Chiari malformation Type I (CM-I) is incompletely understood. The authors report on the outcome of a large group of patients with CM-I that were initially selected for nonsurgical management. Methods The authors identified 147 patients in whom CM-I was diagnosed on MR imaging, who were not offered surgery at the time of diagnosis, and in whom at least 1 year of clinical and MR imaging follow-up was available after the initial CM-I diagnosis. These patients were included in an outcome analysis. Results Patients were followed clinically and by MR imaging for a mean duration of 4.6 and 3.8 years, respectively. Of the 147 patients, 9 had new symptoms attributed to the CM-I during the follow-up interval. During this time, development of a spinal cord syrinx occurred in 8 patients; 5 of these patients had a prior diagnosis of a presyrinx state or a dilated central canal. Spontaneous resolution of a syrinx occurred in 3 patients. Multiple CSF flow studies were obtained in 74 patients. Of these patients, 23 had improvement in CSF flow, 39 had no change, and 12 showed worsening CSF flow at the foramen magnum. There was no significant change in the mean amount of cerebellar tonsillar herniation over the follow-up period. Fourteen patients underwent surgical treatment for CM-I. There were no differences in initial cerebellar tonsillar herniation or CSF flow at the foramen magnum in those who ultimately underwent surgery compared with those who did not. Conclusions In patients with CM-Is that are selected for nonsurgical management, the natural history is usually benign, although spontaneous improvement and worsening are occasionally seen.

Acute obstructive hydrocephalus associated with infratentorial subdural hygromas complicating Chiari malformation Type I decompression

2005 ◽  
Vol 103 (4) ◽  
pp. 752-755 ◽  
Author(s):  
Laurence A. G. Marshman ◽  
Jonathan C. Benjamin ◽  
Sanjiv J. Chawda ◽  
Karoly M. David
Keyword(s):  
Mr Imaging ◽  
Chiari Malformation ◽  
Fourth Ventricle ◽  
Obstructive Hydrocephalus ◽  
External Ventricular Drain ◽  
Type I ◽  
Chiari Malformation Type I ◽  
Shunt Insertion ◽  
Content Type ◽  
Fine Print

✓ Obstructive hydrocephalus complicating foramen magnum decompression (FMD) for a Chiari malformation (CM) Type I is rare. Two female patients (17 and 55 years old) presented with strain-related headaches. In both cases magnetic resonance (MR) imaging studies confirmed a CM Type I, which was accompanied by syringomyelia in one case. Both patients underwent uncomplicated FMD with good initial recovery. Unfortunately, conditions in both patients deteriorated, with severe headaches occurring between Days 5 and 6 post-FMD. Decreased consciousness occurred in one case. In both patients, computerized tomography scanning demonstrated an acute obstructive hydrocephalus associated with bilateral infratentorial extraaxial fluid collections (EAFCs). In addition, left parafalcine and convexity EAFCs were present in one case. An emergency external ventricular drain was required in one patient, with delayed conversion to a ventriculoperitoneal shunt. Spontaneous resolution occurred in the other patient without neurosurgical intervention. In both cases, MR imaging confirmed that each EAFC was subdural, resembled cerebrospinal fluid (CSF), and had distorted the superior cerebellum anteroinferiorly. Despite upper fourth ventricle/aqueduct compromise in one case, normal aqueduct flow artifacts were apparent on examination. All EAFCs resolved spontaneously. Obstructive hydrocephalus complicating FMD is rare but invariably associated with infratentorial EAFCs, which were confirmed to be subdural hygromas in this report. The authors assert that hydrocephalus results from upper fourth ventricle/aqueduct compromise as a result of CSF subdural dissection following a pinhole arachnoid tear on durotomy. Because such hygromas spontaneously resolve, permanent shunt insertion should be avoided.

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