He Hoffman sign Is an abnormal reflex response consisting of flexing the fingers of the hand by pressing the middle finger nail.
Although it is generally associated with pathologies such as pyramidal syndrome, it can occur in healthy people who have exalted reflexes (which is called hyperreflexia). This sign appears to indicate some damage in the spinal cord Or in the brain .
Image from: neuroapys4
The clinical neurological examination was of great importance in the past when there were no technological developments in modern medicine. In it were checked the reflexes to observe the state of health of the person.
However, today, with neuroimaging techniques, these tests have less weight when making clinical decisions.
The description of the Babinski reflex Or plantar reflex in 1896 prompted neurologists to look for other reflexes. The anatomical region in which the reflexes were most investigated were the lower limbs.
Abnormal reflexes in the upper limbs were less constant, more difficult to obtain and with less diagnostic significance. Although the Hoffman sign has been used for more than a hundred years to detect pathologies.
Its name comes from the German neurologist Johann Hoffman (1857-1919), who discovered it at the end of the 19th century. However, who wrote for the first time on this sign was his assistant Curschmann in 1911.
The signs of Hoffman and Tromner are the signs most used clinically with respect to the upper extremities, to indicate problems in the corticospinal tract.
Hoffman's reflection is sometimes mistakenly called"Babinski's reflection of the upper limb". However, they are different reflections and should not be confused.
Johann Hoffmann
The Hoffman's sign is also known as a digital reflex and was used as a test for disease of the corticospinal tract of the pyramidal pathway.
The presence of this reflex may indicate an affectation of the Motor neurons Superior that compose the pyramidal way. These neurons are responsible for the voluntary movements of the upper limbs.
When they are affected, in addition to Hoffman's sign they produce other symptoms such as hypertonia (increased muscle tone), weakness, hyperreflexia, rhythmic and involuntary contractions of the muscles, or difficulties in making precise movements with the hands.
How do you get the Hoffman sign?
To get the Hoffman sign take the relaxed hand of the patient with the wrist flexed down and the heart finger partially flexed. The examiner will hold the middle finger of the patient by placing it between his index finger and his middle finger.
This will make a strong movement with your thumb striking or pinching the nail of the patient's middle finger. However, it can also be observed by striking the fingernail of the index finger or the ring finger.
It is said that the Hoffman sign is present if there is the adduction of the thumb and the flexion of the index finger. Sometimes the flexing of the remaining fingers is also present.
In addition, it has been observed that flexing or extending the neck may worsen this sign on some occasions.
What does the sign of Hoffman indicate?
The Hoffman sign indicates damage to the corticospinal tract of the pyramidal pathway. It is a set of nerve fibers that travel from the cerebral cortex Until the spinal cord . Its function is to transmit nerve impulses to perform voluntary movements.
These damages can be bilateral or unilateral. When one-sided damage occurs, the side of the body opposite the location of the lesion is affected. Thus, this sign can be presented in one hand or in both, depending on whether it is unilateral or bilateral.
The Hoffman sign indicates the presence of hyperreflexia. It accompanies a variety of conditions, such as Hyperthyroidism , Some types of anxiety and other conditions related to deep tendon reflexes.
Hyperreflexia due to hyperthyroidism usually produces bilateral findings. While structural damage to the brain, such as a tumor , Will give rise to a unilateral reflex.
This sign is also used to evaluate diseases of the cervical spine. Compared with the Babinski's sign, Hoffman's sign is more prevalent in patients who have been treated surgically for myelopathies.
Myelopathies are chronic disorders of the spinal cord. They are usually referred to those that are not due to trauma or inflammation. Some authors indicate that e The Hoffman sign is more likely in patients with less severe neurological problems.
Apparently, the Hoffman sign can also be an indicator of multiple sclerosis . It is observed when there have been injuries in the nerve motor or spinal cord in the part of the nerves that control the movements of the hands (like C5).
In patients with disease in the lumbar spine, but without cervical spine related symptoms, this sign is an indicator of a hidden compression in the cervical spine.
However, in a study by Glaser, Cura, Bailey and Morrow (2001), who analyzed 165 patients with cervical spinal cord compression, they concluded that the Hoffman test is not a reliable tool for predicting this condition.
They observed a significant incidence of Hoffman's sign in healthy people while they found patients with cord compression who did not have this sign.
On the other hand, in a study by Sung and Wang (2001), asymptomatic patients with the Hoffman sign were studied. Cervical X-rays and magnetic resonance imaging were performed on all 16 patients.
The magnetic resonance Reflected pathologies in all patients. Fourteen of them had Spondylosis cervical. 15 had compression of the marrow by hernia of nucleus pulposus. While one of them had a Herniated disc In T5-T6, with its resulting compression.
It is important to mention that the Hoffman sign does not always indicate the existence of a pathology of the pyramidal pathway. It has sometimes been observed in people with"living"reflexes such as those who are suffering from anxiety or are under the effects of stimulant substances.
However, when accompanied by other pathological reflexes or abnormal symptoms, this sign implies some nervous system .
References
- Barman, B. (2010). Clinical Sign Revisited: Hoffman's Sign. Indian Journal of Medical Specialties, 1 (1), 44-45.
- Campbell, W. W., & DeJong, R. N. (2013). DeJong's The Neurologic Examination. Lippincott Williams & Wilkins: Philadelphia.
- Glaser, J.A., Curé, J.K., Bailey, K.L., & Morrow, D.L. (2001). Cervical spinal cord compression and the Hoffmann sign. Iowa Orthopedic Journal, 21, 49-52.
- Hoffman Sign: Red Flag for Cervical Myelopathy. (S.f.). Retrieved on April 9, 2017, from Eorthopod: eorthopod.com.
- Hoffman's sign. (January 21, 2008). Obtained from Mult Sclerosis: mult-sclerosis.org.
- Hoffman's Sign. (11 April 2012). Retrieved from"Wheeless textbook of orthopedics: wheelessonline.com".
- Sung, R.D., & Wang, J.C. (2001). Correlation between a positive Hoffmann's reflex and cervical pathology in asymptomatic individuals. Spine, 26 (1), 67-70.