Symptoms of Patients With Chiari Malformation

Publication Date: August 31, 2023
Last Updated: September 29, 2023

Summary of Recommendations

Clinicians may perform foramen magnum decompression surgery on symptomatic patients with CIM to improve pain associated with strain-related headaches. Other symptoms demonstrate more variable response to decompression. (C)

Clinicians should not perform prophylactic surgery on patients with asymptomatic CIM without syrinx. There is a small percentage of patients who develop new or worsening symptoms in the future. (C)

Clinicians should not recommend activity restrictions for patients with asymptomatic CIM without syrinx, as there is no evidence of future harm prevention. (C)

There is insufficient evidence to support routine sleep and swallow studies in patients with CIM without sleep or swallow symptoms. (Insufficient)

Clinicians should not routinely screen asymptomatic siblings or first-degree relatives of patients with CIM. (C)

Recommendation Grading


  • CCOS: Chicago Chiari Outcome Scale
  • CIM: Chiari I Malformation
  • CSF: Cerebrospinal Fluid
  • IONM: Intraoperative Neuromonitoring
  • MRI: Magnetic Resonance Imaging
  • PFD: Posterior Fossa Decompression
  • PFDD: Posterior Fossa Decompression With Duraplasty
  • SDB: Sleep-disordered Breathing
  • SSEPs: Somatosensory Evoked Potentials


The information in this patient summary should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health.



Patients With Chiari Malformation: Symptoms

Authoring Organization

Publication Month/Year

August 31, 2023

Last Updated Month/Year

November 2, 2023

Document Type


Country of Publication


Document Objectives

Chiari I malformation (CIM) is characterized by descent of the cerebellar tonsils through the foramen magnum, potentially causing symptoms from compression or obstruction of the flow of cerebrospinal fluid. Diagnosis and treatment of CIM is varied, and guidelines produced through systematic review may be helpful for clinicians.

Target Patient Population

All patients with Chiari Malformation

Target Provider Population

Neurologists, neurosurgeons, and other allied clinicians treating adults and children with Chiari Malformation

Inclusion Criteria

Male, Female, Adolescent, Adult, Child, Infant, Older adult

Health Care Settings

Ambulatory, Outpatient

Intended Users

Nurse, nurse practitioner, physician, physician assistant


Diagnosis, Assessment and screening, Management

Diseases/Conditions (MeSH)

D001139 - Arnold-Chiari Malformation


Chiari Malformation, Chiari I Malformation

Source Citation

Jackson EM, Jernigan S, Raskin JS, Ackerman LL, Infinger LK, Maher CO, Niazi T, Pattisapu JV, Qaiser R, Quinsey C, Rocque BG, Silberstein H, Vachhrajani S, Bauer DF. Congress of Neurological Surgeons Systematic Review and Evidence-Based Guidelines for Patients With Chiari Malformation: Symptoms. Neurosurgery. 2023 Oct 1;93(4):727-730. doi: 10.1227/neu.0000000000002634. Epub 2023 Aug 30. PMID: 37646519.