What Is Hoffmann's Sign?

Hoffmann's sign, Hoffmann-Tinel sign, and Tinel's sign are methods that physicians use to determine nerve damage. By applying light percussion or flicking specific nerves in fingers or the wrist, physical responses or sensations experienced by patients may indicate local or nervous system irritation. Individuals may or may not complain of or exhibit other symptoms related to a specific disease process. The presence of Hoffmann's sign does not provide a definitive diagnosis and generally requires reflex testing in other bodily areas along with blood work and imaging studies.

Dr. Paul Hoffmann, a German physiologist, receives credit for developing Hoffmann's sign. Clinicians generally perform the assessment by flicking the bottom of the fingernail on the index, middle, or ring finger. Twitching or flexion displayed in the other fingers on the hand in response generally represents a positive Hoffmann's sign. Neurology studies indicate that a positive sign usually indicates upper motor abnormalities caused by compression or irritation of the spinal column. Under these circumstances, the nerve cells remain in a constant state of excitation known as tetany.

Patients exhibiting a positive sign may be suffering from a number of conditions, including multiple sclerosis and spinal stenosis. Anxiety disorders or hyperthyroidism might also produce the reflex response. Multiple sclerosis patients generally develop lesions, or scarring, along the spinal nerves after nerve demyelination occurs, which compresses or irritates sensitive nerve tissue. Patients diagnosed with spinal stenosis also usually complain of extremity tingling or weakness and back pain. Narrowing of the vertebral cavity or spinal misalignment also applies pressure on the spinal nerves, producing various symptoms away from the actual site of involvement.

Determining specific causes for a positive Hoffmann's sign and associated symptoms generally requires additional testing. Physicians might perform a Babinski reflex test in which the bottom of the foot is stroked. A flaring up and out of the toes usually indicates brain involvement. Laboratory blood tests might indicate autoimmune disorders, inflammatory conditions, or infections, in addition to other possible medical conditions. Imaging studies typically indicate specific areas in the brain or spinal column that are affected by disease.

The Tinel sign, developed by French neurologist Jules Tinel, is associated with carpal tunnel syndrome. Patients place an arm palm side up on a flat surface. Physicians tap the wrist over the creased area, which contains the ulnar nerve. Individuals with carpal tunnel syndrome usually experience tingling or paralysis in the fingers of the hand because of compressed nerve tissue. Further physical assessment usually involves other sensation responses elicited by the exertion of pressure on the wrist or by having the patient hyperextend the affected hand.