Barking vocalizations and shaking movements in a 13-year old girl

Erica is a 13-year old female who was hospitalized for a 4-week history of "barking" noises and 2 weeks of generalized shaking episodes. Four weeks prior to admission, she had a viral upper respiratory infection (URI) with cough which was treated with over-the-counter cough syrup. After resolution of the URI, she developed a persistent cough that turned into a "bark"-like vocalization. Both the mother and patient demonstrated the bark as an "arf" sound like that of a small dog at times, a large dog at others. These vocalizations were unrelenting, occurring 3-10 times per minute only while awake. They were not precipitated by any known factors nor were there alleviating factors. She could not voluntarily suppress the sound. In addition to the vocalizations, episodes of generalized shaking of the extremities began 2 weeks prior to admission. According to Erica's mother, each episode lasted about 10-60 seconds and occurred 30-40 times a day only when she was awake. These episodes were not rhythmic or symmetric, and they were not associated with bowel or bladder incontinence. There was no alteration of consciousness following the episodes. Erica denied any recollection of the barking or shaking. The medical evaluation did not reveal an etiology. It included a complete physical examination, a neurological examination, biochemical laboratory studies, and a negative video EEG study that captured 10 episodes of shaking. Child psychiatry was consulted. Erica was a pleasant, quiet female with slightly constricted affect and a normal speech pattern. She reported that she was a straight-A honors student who had difficulty trusting others; she said that she had no friends, only "associates." She said that she had periods of feeling "sad" and crying easily, but could not identify any recent stressful event. Episodes of barking and shaking diminished during the hospitalization. Erica was discharged home with outpatient psychiatric follow-up.