Bekhterev-Jacobsohn reflex
Encyclopedia
The Bekhterev-Jacobsohn reflex, or Jacobsohn's finger flexion sign, is a clinical sign
found in patients with pyramidal tract lesions
of the upper limb. In this condition, stroking the dorsum
of the forearm, in the area of the distal radius
, with the arm supine
causes abduction
of the hand and flexion
of the fingers.
It is analogous to the Bekhterev-Mendel reflex
in the lower limb.
The reflex is named after Vladimir Bekhterev
and Louis Jacobsohn-Lask
.
Medical sign
A medical sign is an objective indication of some medical fact or characteristic that may be detected by a physician during a physical examination of a patient....
found in patients with pyramidal tract lesions
Upper motor neurone lesion
An upper motor neuron lesion is a lesion of the neural pathway above the anterior horn cell or motor nuclei of the cranial nerves. This is in contrast to a lower motor neuron lesion, which affects nerve fibers traveling from the anterior horn of the spinal cord to the relevant muscle.Upper motor...
of the upper limb. In this condition, stroking the dorsum
Dorsum (biology)
In anatomy, the dorsum is the upper side of animals that typically run, fly, or swim in a horizontal position, and the back side of animals that walk upright. In vertebrates the dorsum contains the backbone. The term dorsal refers to anatomical structures that are either situated toward or grow...
of the forearm, in the area of the distal radius
Lower extremity of radius
-Articular surfaces:It is provided with two articular surfaces - one below, for the carpus, and another at the medial side, for the ulna.* The carpal articular surface is triangular, concave, smooth, and divided by a slight antero-posterior ridge into two parts...
, with the arm supine
Supination
Supination is a position of either the forearm or foot; in the forearm when the palm faces anteriorly, or faces up . Supination in the foot occurs when a person appears "bow-legged" with their weight supported primarily on the anterior of their feet.The hand is supine in the anatomical position...
causes abduction
Abduction (kinesiology)
Abduction, in functional anatomy, is a movement which draws a limb away from the median plane of the body. It is thus opposed to adduction.-Upper limb:* of arm at shoulder ** Supraspinatus** Deltoid* of hand at wrist...
of the hand and flexion
Flexion
In anatomy, flexion is a position that is made possible by the joint angle decreasing. The skeletal and muscular systems work together to move the joint into a "flexed" position. For example the elbow is flexed when the hand is brought closer to the shoulder...
of the fingers.
It is analogous to the Bekhterev-Mendel reflex
Bekhterev-Mendel reflex
The Bekhterev-Mendel reflex, also known as the Mendel reflex or Mendel-Bekhterev reflex, is a clinical sign found in patients with pyramidal tract lesions...
in the lower limb.
The reflex is named after Vladimir Bekhterev
Vladimir Bekhterev
Vladimir Mikhailovich Bekhterev was a Russian Neurologist and the Father of Objective Psychology. He is best known for noting the role of the hippocampus in memory, his study of reflexes, and Bekhterev’s Disease...
and Louis Jacobsohn-Lask
Louis Jacobsohn-Lask
Louis Jacobsohn-Lask was a German neurologist and neuroanatomist. He studied medicine at the University of Berlin under Heinrich Wilhelm Waldeyer, Rudolf Virchow, Emil du Bois-Reymond, Ernst Viktor von Leyden and Robert Koch...
.