Elsevier

World Neurosurgery

Volume 110, February 2018, Pages e60-e66
World Neurosurgery

Original Article
Predictive Factors of Headache Resolution After Chiari Type 1 Malformation Surgery

https://doi.org/10.1016/j.wneu.2017.10.070Get rights and content

Background

Headache is the main and often isolated symptom of patients with Chiari type 1 malformation (CM1). Classically described as occipital and exacerbated by cough, headaches may be poorly characterized, making it difficult to establish CM1 as the underlying cause. Current guidelines for surgical posterior fossa decompression are undefined. The challenge is to distinguish headaches related to CM1 from headaches coincidentally coexisting with CM1. We aimed to determine predictive factors of headache resolution after surgery and applied to our cohort the Chiari Severity Index, a recently developed predictive prognostic score.

Methods

This retrospective study enrolled 49 patients with CM1 and preoperative headache. Standardized telephone interviews regarding headaches before and after surgery were conducted by the same neurologist; magnetic resonance imaging morphometric analyses were performed by an independent neuroradiologist. Headache resolution was defined as ≥50% reduction in frequency of headache days.

Results

Preoperative factors of headache resolution after multivariate analysis were attack duration <5 minutes (P = 0.001), triggering by Valsalva maneuvers (P = 0.003), severe intensity of attack (P = 0.05), occipital location (P = 0.05), and greater number of headache days per month (P = 0.04). These characteristics are part of International Headache Society diagnostic criteria for headache attributed to CM1. No radiologic predictive factor was demonstrated. Postoperative improvement was inversely correlated with Chiari Severity Index.

Conclusions

This study confirms the relevance of International Headache Society criteria to identify headaches related to CM1. We propose their systematic use in a preoperative questionnaire.

Introduction

Chiari type 1 malformation (CM1) is characterized by ectopia of cerebellar tonsils through the foramen magnum into the spinal canal. A syrinx can be associated at the time of diagnosis or may appear secondarily and manifest with medullary symptoms. The exact prevalence of CM1 in the general population is unknown but is estimated to be 0.5%–0.9% in adults and 1% in children.1, 2 The onset of CM1 symptoms usually occurs in the second or third decade. Headache is the most common symptom, occurring in 30%–90% of patients.3, 4, 5 Headaches are typically posterior, exacerbated by cough or Valsalva maneuvers or induced by cervical motion. Headaches attributed to Chiari criteria were established by the International Classification of Headache Disorders, third edition.6 Headaches can be isolated or associated with other symptoms, such as vertigo, ataxia, and limb weakness or numbness. Several theories have been advanced to explain the physiopathologic mechanisms of CM1. At the present time, these mechanisms are thought to involve obstruction to the flow of cerebrospinal fluid (CSF) in the craniocervical junction and lower intracranial compliance.7, 8, 9, 10 Management is primarily surgical, and the goal is to restore normal CSF flow and normal intracranial compliance as well, decompressing the posterior fossa. To date, evidence-based guidelines for surgical intervention are undefined. There is wide agreement for a nonoperative approach in asymptomatic patients, unless there is a multilevel syrinx.11 In contrast, faced with isolated clinical manifestations, the difficulty lies in establishing the imputability of CM1, which would then justify a decompressive procedure. In the absence of objective neurologic signs, the neurosurgeon mainly relies on headache symptoms. However, headaches are often polymorphous and poorly characterized. The whole pattern of CM1 headache is not well established in the literature.12, 13, 14 Given the high prevalence of primary headaches, such as migraine or tension headache,15, 16, 17 the challenge is to distinguish headaches actually related to CM1 from headaches that coexist in independently with CM1. Standardized prognostic tools are needed to stratify the probability of postoperative improvement of these headaches. To date, several studies have attempted to identify predictive factors of favorable outcomes in patients with CM1, but none of them focused on the headache itself.18, 19 More recently, researchers at the University of Washington have developed a preoperative grading system, the Chiari Severity Index (CSI), which takes into account headache as well as syrinx characteristics.20, 21 In this study, we sought to better characterize headache patterns and to determine clinical and radiologic predictive factors of headache resolution after surgery. To determine if this score is reproducible, we then applied the CSI to our cohort.

Section snippets

Study Design and Subjects

This retrospective clinical study was conducted between May 2011 and May 2016 at Rouen University Hospital. The study protocol was approved by the Ethics Committee of Rouen University Hospital. All patients were referred to the Department of Neurosurgery for surgical decompression of the posterior fossa in the context of CM1. We included all patients with CM1 and preoperative headaches not attributed to another evident cause and who had a postoperative follow-up of at least 6 months.

The

Clinical and Surgical Characteristics

In our cohort of 49 patients, mean age at diagnosis was 37.4 years (IQR, 18–60 years) with a male-to-female sex ratio of 3:1. Headache was the main symptom in 37 patients (75.5%). The mean headache duration before surgery was 3.4 years (IQR, 0.5–10 years). Headaches were associated with other symptoms in 41 patients (83.6%) and were isolated in 8 patients (16.3%). Main headache characteristics are presented in Figure 2. Of 49 patients, 28 (57.2%) had improved headache and 21 (42.8%) had

Discussion

The aim of this retrospective study was to investigate the predictive factors of headache resolution after surgery in patients with CM1. An improvement in headache, regardless of type, was observed in 57% of our cohort. In the literature, this rate is approximately 70%–80%, but most studies considered patients with classic cough headache only and not headaches with atypical features.26, 27, 28 Symptoms other than headache improved in 76% of our patients, which is consistent with data in the

Conclusions

This study emphasizes the relevance of IHS criteria for the identification of headaches related to CM1. Each of these criteria seems to be an individual predictive factor of headache resolution after surgery. The systematic use of a preoperative questionnaire that incorporates these IHS criteria could be helpful. Finally, no predictive factor could be identified on conventional MRI, emphasizing the role of lower compliance and CSF flux disturbances as responsible for headache rather than a

Acknowledgments

The authors thank all the patients who were involved in this study Nikki Sabourin-Gibbs, Rouen University Hospital, for her help in editing the manuscript.

References (36)

  • L.A. Aitken et al.

    Chiari type I malformation in a pediatric population

    Pediatr Neurol

    (2009)
  • M.C. Victorio et al.

    Headache and Chiari I malformation in children and adolescents

    Semin Pediatr Neurol

    (2016)
  • L.K. Mannix

    Epidemiology and impact of primary headache disorders

    Med Clin North Am

    (2001)
  • M.C. Speer et al.

    Review article: Chiari type I malformation with or without syringomyelia: prevalence and genetics

    J Genet Couns

    (2003)
  • T.H. Milhorat et al.

    Chiari I malformation redefined: clinical and radiographic findings for 364 symptomatic patients

    Neurosurgery

    (1999)
  • A.D. Elster et al.

    Chiari I malformations: clinical and radiologic reappraisal

    Radiology

    (1992)
  • V. Nohria et al.

    Chiari headaches

    Neurology

    (1993)
  • The International Classification of Headache Disorders, 3rd edition (beta version)

    Cephalalgia

    (2013)
  • N. Alperin et al.

    Magnetic resonance imaging-based measurements of cerebrospinal fluid and blood flow as indicators of intracranial compliance in patients with Chiari malformation

    J Neurosurg

    (2005)
  • J.W. McVige et al.

    Neuroimaging and the clinical manifestations of Chiari malformation type I (CMI)

    Curr Pain Headache Rep

    (2015)
  • C.A. Sansur et al.

    Pathophysiology of headache associated with cough in patients with Chiari I malformation

    J Neurosurg

    (2003)
  • R.A. Bhadelia et al.

    CSF flow dynamics in Chiari I malformation

    AJNR Am J Neuroradiol

    (2000)
  • E. Schijman et al.

    International survey on the management of Chiari I malformation and syringomyelia

    Childs Nerv Syst

    (2004)
  • F.R. Taylor et al.

    Headache and Chiari I malformation: clinical presentation, diagnosis, and controversies in management

    Curr Pain Headache Rep

    (2002)
  • I. Toldo et al.

    Headache in children with Chiari I malformation

    Headache

    (2014)
  • A.I. Scher et al.

    Prevalence of frequent headache in a population sample

    Headache

    (1998)
  • J. Castillo et al.

    Epidemiology of chronic daily headache in the general population

    Headache

    (1999)
  • M.J. McGirt et al.

    Symptom recurrence after suboccipital decompression for pediatric Chiari I malformation: analysis of 256 consecutive cases

    Childs Nerv Syst

    (2008)
  • Cited by (27)

    • The Dark Side of Chiari Malformation

      2023, World Neurosurgery
    • Clinical Manifestations of Chiari I Malformation

      2023, Neurosurgery Clinics of North America
    • Assessing Clinical Outcome Measures in Chiari I Malformation

      2023, Neurosurgery Clinics of North America
    • Chiari Malformation in Children

      2021, Pediatric Clinics of North America
      Citation Excerpt :

      Approximately 80% of patients meeting IHS criteria for CM1-related headache will have headache resolution after Chiari decompression. Only half of patients with other headache types had improved after Chiari decompression.15,29 Care should be taken when recommending surgery for CM1 when headache is the only symptom.

    View all citing articles on Scopus

    Conflict of interest statement: The authors declare that the article content was composed in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

    View full text