• progressive encephalomyelitis with rigidity
• refractory asthma
• diagnosis

Refractory asthma may include diseases other than bronchial asthma.¹ We report a 19 year old woman with stridor who developed progressive encephalomyelitis with rigidity (PER).

The patient had been undergoing treatment with prednisolone for a diagnosis of refractory asthma but she stopped taking steroids in March 1999 due to avascular necrosis of the femoral heads. She was admitted to hospital in January 2001 because the persistent dyspnoea and paroxysmal board-like rigidity of the extremities became exacerbated after steroid cessation. On admission she was bedridden in a dystonic position. She had miosis, stridor, urinary retention, dysaesthesia below the Th6 level, and tremor and rigidity of the masseter muscle and extremities, but she did not have opisthotonus. She was diagnosed with PER because the continuous motor unit discharges were seen on the surface electromyogram to decrease after diazepam infusion. While observing the larynx, persistent glottal closure was observed (fig 1A) and the glottis opened normally only for brief moments (fig 1B). She recovered from the dyspnoea and stridor after a tracheostomy. Her antiglutamic acid decarboxylase antibody was negative, and spinal fluid examination showed an increased protein level of 41 mg/dl which decreased to 17 mg/dl with steroid treatment. Her symptoms partially improved with steroid pulse therapy.

PER, first reported as a variant of stiff person syndrome by Kasperek and Zebrowski in 1971,² is characterised by muscle pain in the extremities, the trunk, or the face due to progressive rigidity.³ It was unlikely that this case had asthma because the tracheostomy improved her stridor and dyspnoea. The abducting muscle was observed to work normally, indicating that hypertonia of the adducting muscles might have caused the severe stenosis of the glottic space. We conclude that PER should also be considered in cases of refractory asthma.