patients with helps describe a recognizable pattern of symptoms that include episodic choking and coughing. the choking is due to a unilateral contraction of the throat. if the contraction is in the pharynx, the patient will typically be able to detect which side of the throat is affected. even a bystander may be able to feel that the muscles on one side of the throat are in spasm. if the larynx is affected, however, the patient may not be able to feel which side is affected but will report a circumferential choking. these choking episodes tend to worsen over the years in intensity, frequency and duration. initially, episodes last for a few seconds but can eventually progress to several minutes. the throat contraction can make breathing difficult causing stridor (not wheezing) and the patient have reported losing consciousness. like hemifacial spasm, helps is one of the very few movement disorders that can occur while sleeping. the unpredictable but inevitable choking episodes typically cause significant anxiety for the patient and may lead to a psychiatric misdiagnosis. the choking episodes can lead to intubation in the emergency room and rarely to elective tracheostomy. in between episodes, patients are normal. repeated episodes of spontaneous severe choking followed shortly afterwards by a completely normal examination may also increase the likelihood of a psychiatric misdiagnosis. patients have described different triggers for these choking episodes including loud or prolonged talking, and exercise but they can also occur spontaneously.