Horner's syndrome in a patient presenting with a spontaneous pneumothorax.

Spontaneous pneumothoraces are a common thoracic problem presenting to an Accident and Emergency (A&E) department. The symptoms and signs are well described and a chest x-ray examination is usually diagnostic. However the neurological signs, specifically a Horner's syndrome on the ipsilateral side, are not widely recognised. This case illustrates the association and emphasises that when assessing a patient with a suspected spontaneous pneumothorax, an ipsilateral Horner's syndrome supports the clinical diagnosis. Further, its presence makes a tensioning pneumothorax, or as in this case a pneumothorax with significant collapse and apical adhesions, more likely. No previous case reporting the association has had the opportunity for thorascopic assessment and demonstration of likely cause.