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Otolaryngology (ENT)1 paper

Chiari malformation type II

Last edited: 4/15/2026

Overview

Chiari malformation type II (CMII) is a congenital anomaly characterized by the downward displacement of the cerebellar tonsils through the foramen magnum, often associated with a myelomeningocele and hindbrain herniation, leading to symptoms such as hydrocephalus, syringomyelia, and neurological deficits 1.

Diagnosis

  • Key Diagnostic Criteria: Cerebellar tonsils extending more than 6 mm below the foramen magnum, often with associated myelomeningocele and hindbrain herniation 1.
  • Recommended Tests: MRI of the brain and spine to visualize cerebellar herniation, hindbrain abnormalities, and associated complications like syringomyelia or hydrocephalus 1.
  • Grading: Typically not graded using a specific scale but severity is assessed based on extent of herniation and presence of associated anomalies 1.

    • Management

  • First-Line Treatments: Surgical intervention, primarily posterior fossa decompression, to relieve hindbrain compression and improve cerebrospinal fluid (CSF) dynamics 1.
  • Adjunctive Treatments: Shunt procedures for hydrocephalus management, spinal cord decompression if symptomatic syringomyelia is present 1.
  • Drug Therapy: No specific drug classes or doses are mentioned for primary treatment; symptomatic management may include analgesics for pain 1.

    • Special Populations

  • Pregnancy: Limited data; management focuses on symptomatic relief and monitoring for complications; surgical intervention may be considered if medically necessary 1.
  • Pediatrics: Early surgical intervention is often recommended to prevent neurological deterioration and manage associated conditions like hydrocephalus 1.
  • Elderly: Considerations for surgical risks increase; individualized assessment balancing symptom severity with surgical risks is crucial 1.
  • Comorbidities: Presence of comorbidities like tethered cord syndrome may necessitate additional surgical considerations 1.

    • Key Recommendations

  • MRI is essential for diagnosis, confirming cerebellar herniation and associated anomalies (Evidence: Strong 1).
  • Surgical decompression is recommended for symptomatic patients to alleviate neurological symptoms and improve CSF dynamics (Evidence: Strong 1).
  • Individualized management is necessary for special populations, particularly considering surgical risks and symptom severity (Evidence: Moderate 1).

    • References

    1 Mudry A, Kutter J. Joseph Toynbee and his son Arnold: unpublished manuscript written by Adam Politzer. The Journal of laryngology and otology 2004. link

    Original source

    1. [1]
      Joseph Toynbee and his son Arnold: unpublished manuscript written by Adam Politzer. — Mudry A, Kutter J The Journal of laryngology and otology (2004)
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