The Reporter: December 1997, Vol.8, No.5
Innovation in Research
The Air Pulse Sensory Stimulator

 Pneumonia after stroke kills 50,000 people annually in the United States and is the most common cause of morbidity and mortality after stroke in the elderly. Pneumonia is the most frequent reason for discharge of patients from a nursing home to a hospital, accounting for yearly expenditures by Medicare of more than $3 billion.

 " Just as some patients suffer from motor paralysis in their limbs after a stroke, they can also experience sensory paralysis in their throat after a stroke," says Dr. Jonathan E. Aviv, co-inventor of a recently FDA-approved device called the Air Pulse Sensory Stimulator. " Knowledge of sensory discrimination in this area will lead to more precise therapeutic maneuvers by clinicians to ensure a safer swallow for their patients and may reduce overall pneumonia incidence and pneumonia-related expenses."

 The Air Pulse Sensory Stimulator can easily assess a sensory deficit and, once detected, specific dietary and behavioral treatments can lower the risk of developing pneumonia. With brain stem stroke, for example, one half of the throat is numb. By using the Air Pulse Sensory Stimulator clinicians can now determine which side of the throat is numb and simply have the patient turn their head so that the incoming food is exposed to the side of the throat with normal sensation.

 The Air Pulse Sensory Stimulator consists of a flexible fiber optic endoscopic tube, about the size of a piece of spaghetti, connected to an air pulse generator. When the tube is placed through the nose into the middle of the throat, pulses of air, varying in duration and intensity, are delivered to elicit an involuntary throat reflex that causes the vocal cords to close. The reflex, which normally occurs during swallowing, prevents fluids or food from entering the trachea and lungs. The reflex occurs in patients with normal throat sensitivity but does not occur in those with sensory deprivation. The procedure can be performed at the bedside or in the office and takes about 10 minutes. One of the key applications of sensory testing is its combination with endoscopic swallowing evaluations to create Flexible Endoscopic Evaluation of Swallowing with Sensory Testing (FEESST). During FEESST, food coloring is placed in the food and one observes through an endoscope where the food is traveling in the throat during a swallow. With FEESST one can obtain a complete sensory and motor evaluation of swallowing at half the cost of a comparable X-ray swallowing test, which can not be performed at the bedside. FEESST promises to fill a gap in geriatric medicine and will help clinicians make better treatment choices for their patients after stroke and chronic neurological disease.