Nerve Testing (PSSD)

Neurosensory testing is a non-invasive technique for assessing nerve damage by measuring the pressure threshold felt in the skin. By testing an area of the skin that corresponds to a specific nerve, the extent of nerve damage can be determined by the amount of pressure needed for a person to feel the touch of the testing device.

An individual with a healthy nerve can feel a very light touch and has a low pressure of threshold. However, a person with a nerve that has been damaged by compression or neuropathy will require a greater than normal pressure for the touch to be felt and, therefore, have an abnormal pressure threshold.

The Pressure Specified Sensory Device (PSSD), is used to make these measurements of pressure threshold. This device consists of two blunt probes and sensitive transducers to measure pressure without causing pain to the person being tested.

The PSSD was developed by a hand surgeon and an aerospace engineer and was designed using aerospace technology miniaturized for medicaltesting. It is a precision measuring device and is calibrated to reference standards from the United States National Institute of Standards and Technology to allow very accurate test information.

Your Neurosensory Test will be done in a quiet exam room and you will be resting comfortably. The individual performing the sensory test has been certified by Sensory Management Services. He or she will instruct you where the Pressure Specified Device will be placed. You will press a button when you feel the touch of it.

There are four different types of sensory tests and, depending on what is necessary, you will be asked to press a button when you feel one point, two points, one point moving, or two points moving on the surface of your skin. The examiner will touch the area being tested five times or so, and then the pressure threshold measurements will be stored in the computer. The sensory testing will be done on both the left and right sides.

You may be referred for a Neurosensory Test after the first visit to a physician. The test results, along with the physical examination and medical history, will assist the physician in arriving at a diagnosis of your medical situation. The test identifies if there is a nerve problem. As treatment progresses, you will have additional sensory testing to document that the nerve is healing and to help determine if other treatment is needed.

Some individuals will have Neurosensory Testing done every year to follow a nerve condition that is abnormal and not serious but that may become very serious over time. Persons taking annual tests include those with diabetes, those exposed to lead or other chemicals, persons undergoing chemotherapy or kidney dialysis, or those with a job that requires a lot of arm movement or standing can develop serious nerve problems. Your physician is able to compare your annual sensory tests to see if the nerve condition is worsening and to determine when treatment is needed.