{
    "abstract": "Radiographic characterization of Chiari malformation (CM) has historically focused on caudal tonsillar herniation (CH) below the foramen magnum. Previously, we published evidence linking ventral tonsillar herniation (VH) and medullary symptoms in very young children. We sought to extend that investigation by studying the radiographic and clinical significance of VH in adults diagnosed with CM.\nWe retrospectively reviewed adults with cerebellar ectopia who underwent posterior fossa decompression with or without duraplasty (PFD/D) at our institution. VH was defined as tonsils crossing a line bisecting the caudal medulla at the level of the foramen magnum on axial MRI. Degree of VH was measured as distance between this bisecting line and the ventral tip of the herniated tonsil. Dorsal brainstem compression was qualitatively determined by assessing for obliteration of CSF space between the dorsal brainstem and the tonsils.\nOut of 89 cases reviewed, 54 had some degree of VH. Compared with those without VH, the VH group was significantly older in age and more likely to also present with dorsal brainstem compression and headaches. No correlation was observed between degrees of CH and VH in the VH group. The degree of VH significantly decreased 3 months after PFD/D.\nVH is relatively common in CM patients and might be an important independent radiographic metric to evaluate and consider as part of the decision-making process, especially in those presenting with Chiari-like symptomatology referable to the medulla but who do not meet the traditional criteria of cerebellar ectopia greater than 5 mm.",
    "authors": [
        {
            "affiliation": "Department of Neurological Surgery, Weill Cornell Medicine/NewYork Presbyterian Hospital, New York, New York, USA.",
            "firstname": "John K",
            "initials": "JK",
            "lastname": "Chae"
        },
        {
            "affiliation": "Department of Neurological Surgery, Weill Cornell Medicine/NewYork Presbyterian Hospital, New York, New York, USA.",
            "firstname": "Arsalan",
            "initials": "A",
            "lastname": "Haghdel"
        },
        {
            "affiliation": "Department of Neurological Surgery, Weill Cornell Medicine/NewYork Presbyterian Hospital, New York, New York, USA.",
            "firstname": "Alexander",
            "initials": "A",
            "lastname": "Kelly"
        },
        {
            "affiliation": "Department of Neurological Surgery, Weill Cornell Medicine/NewYork Presbyterian Hospital, New York, New York, USA.",
            "firstname": "Amanda",
            "initials": "A",
            "lastname": "Cruz"
        },
        {
            "affiliation": "Department of Neurological Surgery, Weill Cornell Medicine/NewYork Presbyterian Hospital, New York, New York, USA.",
            "firstname": "Myles",
            "initials": "M",
            "lastname": "Wood"
        },
        {
            "affiliation": "Department of Neurological Surgery, Weill Cornell Medicine/NewYork Presbyterian Hospital, New York, New York, USA.",
            "firstname": "Grant",
            "initials": "G",
            "lastname": "Luhmann"
        },
        {
            "affiliation": "Department of Neurological Surgery, Weill Cornell Medicine/NewYork Presbyterian Hospital, New York, New York, USA. Electronic address: jpgreenf@med.cornell.edu.",
            "firstname": "Jeffrey P",
            "initials": "JP",
            "lastname": "Greenfield"
        }
    ],
    "conclusions": null,
    "copyrights": "Copyright \u00a9 2021 Elsevier Inc. All rights reserved.",
    "doi": "10.1016/j.wneu.2021.08.085",
    "journal": "World neurosurgery",
    "keywords": [
        "Brainstem compression",
        "Cerebellar ectopia",
        "Chiari 0.5",
        "Chiari malformation",
        "Tonsillar herniation",
        "Ventral tonsillar herniation"
    ],
    "methods": null,
    "publication_date": "2021-08-30",
    "pubmed_id": "34455094",
    "results": "Out of 89 cases reviewed, 54 had some degree of VH. Compared with those without VH, the VH group was significantly older in age and more likely to also present with dorsal brainstem compression and headaches. No correlation was observed between degrees of CH and VH in the VH group. The degree of VH significantly decreased 3 months after PFD/D.",
    "title": "Ventral Tonsillar Herniation Predicts Headaches in Adults With Chiari Malformation.",
    "xml": "<Element 'PubmedArticle' at 0x788502e66890>"
}