NEW YORK, N.Y., Oct. 7, 1997–The FDA has cleared a device invented at Columbia University College of Physicians & Surgeons that may reduce the incidence of pneumonia in thousands of elderly Americans and stroke patients who develop swallowing disorders. The device, called the Air Pulse Sensory Stimulator, measures sensory loss, or numbness, in the throat and voice box. Numbness in this region can increase the risk of food and secretions inadvertently going into the lungs and causing pneumonia.
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 in this country. 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 dollars.
The sensory testing technology was invented by Jonathan E.. Aviv, M.D., FACS, associate professor of otolaryngology-head & neck surgery, and John H. Martin, Ph.D., associate professor of neurobiology and behavior at the Columbia-Presbyterian Medical Center. “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 Aviv. “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.
“When stroke leaves a patient paralyzed or blind, they know it and so does their physician. But we are finding that some strokes can have serious effects on the sensory and motor functions of the throat without either the patient or physician knowing about it. Because it can be a hidden problem, it can be more serious –and more life threatening– than a stroke symptom like limb paralysis,” says Martin.
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. 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. The work was funded by Office of Clinical Trials; the Florence and Herbert Irving Fellowship; and Pentax Precision Instrument Corporation of Orangeberg, the NY Licensee of the technology.