Cerebellar Tonsillar Herniation Rare Cause of Chronic Cough: A Report
China: Cerebellar tonsillar herniation should be considered in patients with unexplained chronic cough after common causes have been excluded. Careful clinical evaluation, including simple bedside assessments such as the water swallow test, along with multidisciplinary assessment, may facilitate timely diagnosis, a recent case report published in BMC Pulmonary Medicine has shown.
The report, authored by Na Li from the Key Laboratory of Respiratory Disease of Zhejiang Province, Department of Respiratory and Critical Care Medicine, Second Affiliated Hospital of Zhejiang University School of Medicine, China, and colleagues, highlights an unusual presentation of cerebellar tonsillar herniation in which chronic cough was the patient's only symptom.
Chronic cough is most often linked to respiratory conditions, gastroesophageal reflux disease, or allergies. Central nervous system disorders are an uncommon cause, and cerebellar tonsillar herniation—typically associated with neurological symptoms—is rarely identified when cough is the sole clinical manifestation.
The case involved a 61-year-old woman who had experienced a persistent, recurrent cough for one year, which consistently worsened after eating or drinking. Initial investigations for common causes of chronic cough, including chest computed tomography (CT), laboratory tests, allergy assessment, and bronchial challenge testing, did not reveal any abnormalities.
As the patient's symptoms remained unexplained, she underwent evaluation by a multidisciplinary team. A water swallow test, a simple bedside assessment, reproduced coughing episodes during swallowing, raising suspicion of an underlying neurological disorder affecting swallowing function.
Subsequent magnetic resonance imaging (MRI) revealed cerebellar tonsillar herniation, with the cerebellar tonsils extending 10 mm below the foramen magnum, confirming the diagnosis.
The patient underwent posterior fossa decompression with occipital-cervical fusion to relieve compression at the craniovertebral junction. Following surgery, her chronic cough resolved completely. She remained symptom-free throughout one year of follow-up, with no recurrence of cough.
The authors noted that this case highlights the importance of considering neurological causes when patients continue to experience chronic cough despite negative evaluations for more common respiratory, gastrointestinal, or allergic conditions. They emphasized that bedside tests such as the water swallow test can provide valuable clues to swallowing dysfunction and help identify patients who may require neurological imaging.
The researchers concluded that cerebellar tonsillar herniation, although rare, should be included in the differential diagnosis of unexplained chronic cough, particularly when symptoms are triggered by eating or drinking, and routine investigations fail to identify a cause. They added that a multidisciplinary approach combined with targeted clinical assessment can facilitate earlier diagnosis and appropriate treatment, potentially leading to complete symptom resolution in selected patients.
Reference:
Li, N., Guo, J., Hu, Y. et al. Chronic cough caused by cerebellar tonsillar herniation: a case report. BMC Pulm Med (2026). https://doi.org/10.1186/s12890-026-04504-8
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