The natural history of the Chiari Type I anomaly

Restricted access

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.

Abbreviations used in this paper: CM = Chiari malformation; CM-I = CM Type I.

Article Information

Address correspondence to: Federica Novegno, M.D., Department of Pediatric Neurosurgery, Catholic University Medical School, Largo A. Gemelli 1, 00168 Rome, Italy. email: federicanovegno@hotmail.it.

© AANS, except where prohibited by US copyright law.

Headings

Figures

  • View in gallery

    Case 1. Representative T1-weighted MR images. Tonsillar herniation is demonstrated in the image in panel A obtained in 1997 and performed for gait instability. Additional images were obtained in 2000 (B), 2003 (C), 2005 (D), and 2007 (E). In 2007 the neuroradiological findings changed totally, showing complete resolution of the malformation (E).

  • View in gallery

    Case 19. Representative MR images. Sagittal T1-weighted (A) and axial T2-weighted (B) images obtained at diagnosis, showing hindbrain herniation associated with mild ventriculomegaly. After 3 years, the patient presented with progression of hydrocephalus associated with an increase in tonsillar herniation shown on sagittal T1-weighted (C) and axial T2-weighted (D) images.

References

1

Appollonio IMGrafman JSchwartz VMassaquoi SHallett M: Memory in patients with cerebellar degeneration. Neurology 43:153615441993

2

Avellino AMBritz GWMcDowell JRShaw DWEllenbogen RGRoberts TS: Spontaneous resolution of a cervicothoracic syrinx in a child. Case report and review of the literature. Pediatr Neurosurg 30:43461999

3

Avellino AMKim DKWeinberger ERoberts TS: Resolution of spinal syringes and Chiari I malformation in a child. Case illustration. J Neurosurg 84:7081996

4

Bottari PCipriani PChilosi AMPfanner L: The italian determiner system in normal acquisition, specific language impairment, and childhood aphasia. Brain Lang 77:2832932001

5

Caldarelli MDi Rocco C: Diagnosis of Chiari I malformation and related syringomyelia: radiological and neurophysiological studies. Childs Nerv Syst 20:3323352004

6

Caldarelli MNovegno FMassimi LRomani RTamburrini GDi Rocco C: The role of limited posterior fossa craniectomy in the surgical treatment of Chiari malformation Type I: experience with a pediatric series. J Neurosurg 106:3 Suppl1871952007

7

Castillo MWilson JD: Spontaneous resolution of a Chiari I malformation: MR demonstration. AJNR Am J Neuroradiol 16:115811601995

8

Di Rocco CVelardi F: Acquired Chiari type I malformation managed by supratentorial cranial enlargement. Childs Nerv Syst 19:8008072003

9

Galarza MSood SHam S: Relevance of surgical strategies for the management of pediatric Chiari type I malformation. Childs Nerv Syst 23:6916962007

10

Genitori LPeretta PNurisso CMacinante LMussa F: Chiari type I anomalies in children and adolescents: minimally invasive management in a series of 53 cases. Childs Nerv Syst 16:7077182000

11

Girard NLasjaunias PTaylor W: Reversible tonsillar prolapse in vein of Galen aneurysmal malformations: report of eight cases and pathophysiological hypothesis. Childs Nerv Syst 10:1411471994

12

Greenlee JDDonovan KAHasan DMMenezes AH: Chiari I malformation in the very young child: the spectrum of presentations and experience in 31 children under age 6 years. Pediatrics 110:121212192002

13

Haroun RIGuarnieri MMeadow JJKraut MCarson B: Current opinions for the treatment of syringomyelia and Chiari malformations: survey of the Pediatric section of the American Association of Neurological Surgeons. Pediatr Neurosurg 33:3113172000

14

James HEBrant A: Treatment of the Chiari malformation with bone decompression without durotomy in children and young adults. Childs Nerv Syst 18:2022062002

15

Jatavallabhula NSArmstrong JSgouros SWhitehouse W: Spontaneous resolution of isolated Chiari I malformation. Childs Nerv Syst 22:2012032006

16

Kulp MTSortor JM: Clinical value of the Beery visual-motor integration supplemental tests of visual perception and motor coordination. Optom Vis Sci 80:3123152003

17

Kyoshima KBogdanov EI: Spontaneous resolution of syringomyelia: report of two cases and review of the literature. Neurosurgery 53:7627682003

18

Meadows JKraut MGuarnieri MHaroun RICarson BS: Asymptomatic Chiari Type I malformations identified on magnetic resonance imaging. J Neurosurg 92:9209262000

19

Mikulis DJDiaz OEgglin TKSanchez R: Variance of the position of the cerebellar tonsils with age: preliminary report. Radiology 183:7257281992

20

Milhorat THBolognese PA: Tailored operative technique for Chiari type I malformation using intraoperative color Doppler ultrasonography. Neurosurgery 53:8999062003

21

Milhorat THChou MWTrinidad EMKula RWMandell MWolpert C: Chiari I malformation redefined: clinical and radiographic findings for 364 symptomatic patients. Neurosurgery 44:100510171999

22

Munshi IFrim DStine-Reyes RWeir BKHekmatpanah JBrown F: Effects of posterior fossa decompression with and without duraplasty on Chiari malformation-associated hydromyelia. Neurosurgery 46:138413902000

23

Navarro ROlavarria GSeshadri RGonzales-Portillo GMc-Lone DGTomita T: Surgical results of posterior fossa decompression for patients with Chiari I malformation. Childs Nerv Syst 20:3493562004

24

Nishizawa SYokoyama TYokota NTokuyama TOhta S: Incidentally identified syringomyelia associated with Chiari I malformations: is early interventional surgery necessary?. Neurosurgery 49:6376412001

25

Oldfield EHMuraszko KShawker THPatronas NJ: Pathophysiology of syringomyelia associated with Chiari 1 malformation of the cerebellar tonsils. Implications for diagnosis and treatment. J Neurosurg 80:3151994

26

Rafia SPascual-Castroviejo I: Syringohydromyelia. Report of a case which resolved spontaneously. Rev Neurol 32:6356372001

27

Riva DNichelli FDevoti M: Developmental aspects of verbal fluency and confrontation naming in children. Brain Lang 71:2672842000

28

Schijman ESteinbok P: International survey on the management of Chiari I malformation and syringomyelia. Childs Nerv Syst 20:3413482004

29

Sivaramakrishnan AAlperin NSurapaneni SLichtor T: Evaluating the effect of decompression surgery on cerebrospinal fluid flow and intracranial compliance in patients with Chiari malformation with magnetic resonance imaging flow studies. Neurosurgery 55:134413512004

30

Spanò MMercuri ERandò TPantò TGagliano AHenderson S: Motor and perceptual-motor competence in children with Down syndrome: variation in performance with age. Eur J Paediatr Neurol 3:7131999

31

Steinbok P: Clinical features of Chiari I malformations. Childs Nerv Syst 20:3293312004

32

Sudo KDoi SMaruo YTashiro KTerae SMiyasaka K: Syringomyelia with spontaneous resolution. J Neurol Neurosurg Psychiatry 53:4374381990

33

Sun JCSteinbok PCochrane DD: Spontaneous resolution and recurrence of a Chiari I malformation and associated syringomyelia. Case report. J Neurosurg 92:2 Suppl2072102000

34

Sun PPHarrop JSutton LNYounkin D: Complete spontaneous resolution of childhood Chiari I malformation and associated syringomyelia. Pediatrics 107:1821842001

35

Tokunaga MMinami SIsobe KMoriya HKitahara HNakata Y: Natural history of scoliosis in children with syringomyelia. J Bone Joint Surg Br 83:3713762001

36

Tubbs RSLyerly MJLoukas MShoja MMOakes WJ: The pediatric Chiari I malformation: a review. Childs Nerv Syst 23:123912502007

37

Tubbs RSMcGirt MJOakes WJ: Surgical experience in 130 pediatric patients with Chiari I malformations. J Neurosurg 99:2912962003

38

Weinberg JSFreed DLSadock JHandler MWisoff JHEpstein FJ: Headache and Chiari I malformation in the pediatric population. Pediatr Neurosurg 29:14181998

TrendMD

Metrics

Metrics

All Time Past Year Past 30 Days
Abstract Views 179 179 79
Full Text Views 77 77 20
PDF Downloads 67 67 11
EPUB Downloads 0 0 0

PubMed

Google Scholar