Chronic cough caused by cerebellar tonsillar herniation: a case report

BACKGROUND: Chronic cough is most commonly associated with respiratory or gastroesophageal disorders, whereas central nervous system etiologies are rare. Cerebellar tonsillar herniation is typically characterized by neurological manifestations, but cough as an isolated symptom is uncommon. CASE PRESENTATION: A 61-year-old woman presented with a one-year history of recurrent cough that worsened after eating or drinking. Initial respiratory, gastrointestinal, and allergic evaluations, including chest computed tomography (CT), laboratory testing, and bronchial challenge, were unremarkable. Multidisciplinary team assessment prompted a water swallow test, which showed coughing episodes, raising suspicion for central nervous system involvement. Subsequent magnetic resonance imaging revealed cerebellar tonsillar herniation with 10-mm descent below the foramen magnum. The patient underwent posterior fossa decompression with occipital-cervical fusion. Her cough resolved completely postoperatively, with sustained symptom remission at one-year follow-up. CONCLUSIONS: Cerebellar tonsillar herniation may present solely with chronic cough, particularly when common etiologies have been excluded. Thorough clinical assessment, including simple bedside tools such as the water swallow test, and multidisciplinary evaluation can promote timely diagnosis. Cerebellar tonsillar herniation should be regarded as a potential etiologic factor in the differential diagnosis of chronic cough.