What Is a Wartenberg Wheel?

A Wartenberg wheel is an instrument historically used in neurological exams. It consists of a wheel with a series of sharp spokes that can be rolled over the skin to assess a patient’s response to the sensation. This device is not in common use due to concerns about sterility between patients, although some neurologists work with a disposable plastic version if they find it useful for some testing. Other alternative options can include sterilized pins or needles discarded after each use.

The device is named for Robert Wartenberg, a neurologist who worked in the first half of the 20th century. Pinprick testing, as it is known, can be useful in a neurological assessment. Patients should be able to feel the spokes and report back on their location. If their sensations are impaired, this device can be used to pinpoint the area of damage. For example, a spinal nerve root might be malfunctioning, and the corresponding area of the body might not be sending pain sensations up the spine as a result.

This tool can be used in various areas of the body to test sensation and assess a patient’s response. After spinal injuries in particular, regular testing may be part of patient care to monitor for complications. A patient who has recently had spinal surgery, for example, might have a pinprick test on the feet to confirm that they are still sending and receiving messages from the spine. If the patient loses sensitivity, this could indicate swelling, nerve damage, or other surgical complications that need to be addressed to preserve neurological function.

Concerns about the wheel surround the fact that it is hard to sterilize. The spokes are not designed to draw blood, but can pick up infectious organisms, which may become embedded in the wheel mechanism. Washing and sterilizing a steel instrument between uses may not be efficient in a busy practice, and alternatives can be more suitable. In examinations where a Wartenberg wheel is specifically needed, the plastic version can conveniently provide the ability to perform the test with safety for the patient.

Some medical suppliers continue to sell Wartenberg wheels in both steel and plastic versions. They are also retained in medical museums and neurological research facilities as an example of the kind of instruments used historically. If a Wartenberg wheel is used in testing, the neurologist may remove it from sterile packaging in front of the patient to provide assurance that it is safe for use.