A hand screen to monitor Hansen's disease patients with peripheral nerve involvement, using monofilaments and muscle testing as critical elements, was developed by the National Hansen's Disease Program in 1984 and quickly became a standard for testing. Hand screens can be used to create a record of patient status, a serial comparison of nerve involvement progress, and for research.
The National Hansen's Disease Program hand screen focuses on the following:
Sensory abnormality is found more often than is motor (muscle) abnormality. The sensory nerve fibers, in general, are more susceptible to early nerve injury than are muscle nerve fibers. In Hansen's disease, when the palm has a sensory change in function, the loss is usually consistent with a specific branch of the ulnar or median nerve. The hand screen is designed to specifically measure the palmer surface of the hand (associated with a specific peripheral nerve branch) in order to help identify when a specific ulnar or median nerve branch is involved.
When in doubt as to whether there is a sensory loss specific to a peripheral nerve branch, a finding of concurrent loss in muscle function in the same nerve confirms the nerve branch is involved. Generally in more advanced involvement of the peripheral nerve branches from injury or disease, sensory and muscle function are both affected. It is possible to find muscle involvement without measurable sensory change. Occasionally, sensory function returns to normal, or improves, but muscle function is less likely to return if longstanding.
When in doubt as to whether there is a sensory loss specific to a peripheral nerve branch, a finding of concurrent loss in muscle functionin the same nerve confirms the nerve branch is involved. Generally in more advanced involvement of the peripheral nerve branches from injury or disease, sensory and muscle function are both affected. It is possible to find muscle involvement without measurable sensory change. Occasionally, sensory function improves or returns to normal, but muscle function is less likely to return if longstanding.
See Section I. Sensory Testing in the Hand Screen Form for specific tests and measures.
Skin quality is evaluated by observation of various physical characteristics — pliability, mobility, color, integrity and joint range of motion. Particular attention is given to evidence of callus resulting from excessive pressure and scar as these can indicate sensory abnormality. Callus and skin hardness or thickening could result from direct injury from high or low stress on the skin repetitive enough to cause changes in the quality of the skin and other soft tissue. Any injury or infection should be noted. These can easily be drawn in area and size using the hand illustrations on the hand screen.
Measurement of wound size is useful for noting any changes during subsequent patient visits. If a therapist is doing the hand screen, the use of a small goniometer - an instrument used for measuring joint angle — is used to record skin contractures involving the joints of the hand. Noting skin characteristics on a picture of the hands is a simple way to record important skin characteristics.
See Section II. Skin Inspection in the Hand Screen Form for specific tests and measures.
Manual muscle testing is used to assess muscle strength. The technique for muscle grading — indicated on the hand screen form — is a version of the standard technique for grading of muscles used in most clinics. Therapists assign points from 5 to 1, for various degrees of muscle function; 0 for absent function. Other healthcare workers can use a more simplified grading of strong, weak or paralysis. Positioning of the hand for testing is shown on the muscle testing section of the hand screen.
It is important as a minimum to test the muscles noted on the form as essential elements for recording and following patient nerve function. Muscles selected for monitoring are each innervated from one of the major peripheral nerve branches found in the hand and upper extremity — the ulnar, median or radial.
By monitoring muscle function, one can determine the integrity of the specific peripheral nerve innervating those muscles. For example, an ulnar nerve problem can be recognized by the change in function of muscles it innervates, and a median nerve problem can be recognized by the change in function of muscles it innervates.
It is possible to test every muscle for strength, but this can be time consuming and often gives too much detail. A therapist can add additional muscles and positions for a specific patient. This is particularly important when considering reconstructive surgery where some muscles may be transferred to perform functions lost due to the muscle paralysis.
See Section III. Muscle Testing in the Hand Screen Form for specific tests and measures.
The Peripheral Nerve Evaluation was designed to represent a physical examination of the status of the three major nerve branches that innervate the hand. A distinction is specifically made between long standing nerve involvement and more recent loss or progression.
Nerve function can improve with treatment. The examiner can consider treatment aimed at improving nerve function for patients with nerve changes lasting for less than one year. Investigation in direct treatment for the nerve while it is still acute is promising.
An explosion of knowledge has developed recently with respect to neural physiology, with such discoveries as nerve growth factors and chemical agents that encourage and enhance nerve repair after injury. It is expected that direct treatment of the nerve before it has irreversible changes in sensory or motor functions will be increasingly successful. Much more investigation is needed in this area of treatment.
See Section IV. Peripheral Nerve Risk in the Hand Screen Form for specific tests and measures.
This physical disability "indicator" is patterned after that developed by the World Health Organization as a general indicator of disability in Hansen's disease patients worldwide. This indicator is a gross record for estimates of degree and severity of patient disability and helps in the review of program effectiveness. The indicator provides useful information for the clinician in documenting patient status and change, and identification of patients at risk of deformity or disability progression for consideration of intervention techniques.
See Section V. Deformity Risk in the Hand Screen Form for specific tests and measures.