Pyramidal signs indicate that the

pyramidal tract The pyramidal tracts include both the corticobulbar tract and the corticospinal tract. These are aggregations of efferent nerve fibers from the upper motor neurons that travel from the cerebral cortex and terminate either in the brainstem (''cort ...

is affected at some point in its course. Pyramidal tract dysfunction can lead to various clinical presentations such as

spasticity Spasticity () is a feature of altered skeletal muscle performance with a combination of paralysis, increased tendon reflex activity, and hypertonia. It is also colloquially referred to as an unusual "tightness", stiffness, or "pull" of muscles. ...

, weakness, slowing of rapid alternating movements, hyperreflexia, and a positive Babinski sign. The pyramidal tract completes development and myelinization between 2 and 3 years of age. Pyramidal signs occur as a normal phenomena until the age of 2, when the myelinization is finished, and so under this age they aren't considered pathological.

Pathophysiology

The

upper motor neuron Upper motor neurons (UMNs) is a term introduced by William Gowers in 1886. They are found in the cerebral cortex and brainstem and carry information down to activate interneurons and lower motor neurons, which in turn directly signal muscles ...

s from the

central nervous system The central nervous system (CNS) is the part of the nervous system consisting primarily of the brain, spinal cord and retina. The CNS is so named because the brain integrates the received information and coordinates and influences the activity o ...

descend through the pyramidal tracts (i.e., corticospinal tracts), connecting the

brain The brain is an organ (biology), organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It consists of nervous tissue and is typically located in the head (cephalization), usually near organs for ...

and

spinal cord The spinal cord is a long, thin, tubular structure made up of nervous tissue that extends from the medulla oblongata in the lower brainstem to the lumbar region of the vertebral column (backbone) of vertebrate animals. The center of the spinal c ...

and help in controlling voluntary movement of

muscle Muscle is a soft tissue, one of the four basic types of animal tissue. There are three types of muscle tissue in vertebrates: skeletal muscle, cardiac muscle, and smooth muscle. Muscle tissue gives skeletal muscles the ability to muscle contra ...

Irritative phenomena on the upper extremity

The irritative phenomena are present if there is visible flection of the thumb, which goes to opposition: * Hoffmann's sign – The patient's middle finger is flicked from the nail side down using the examiners index finger.
see video
* Tromner's sign - The patient's middle finger is flicked from underneath using the examiner's index finger.
see video
* Juster's sign – A sharp implement is pricked into the hypothenar eminence.

Irritative phenomena on the lower extremity

Extension

Extension phenomena are positive if the great toe dorsiflexes (goes up) following the stimulus: * Babinski reflex: The plantar aspect of the foot is gently stimulated in a line starting a few centimeters distal to the heel and extended to a point just behind the toes, and then turned medially across the transverse arch. This is done slowly over 5-6 seconds. * Roche's sign: Similar to Babinski but done on the external part of the foot. * Chaddock's phenomen: Reaction on sharp irritation on the outer ankle. * Vitek's sign: Repeatedly scrape the tip of big toe. * Oppenheim's phenomen: The

periosteum The periosteum is a membrane that covers the outer surface of all bones, except at the articular surfaces (i.e. the parts within a joint space) of long bones. (At the joints of long bones the bone's outer surface is lined with "articular cartila ...

tibia The tibia (; : tibiae or tibias), also known as the shinbone or shankbone, is the larger, stronger, and anterior (frontal) of the two Leg bones, bones in the leg below the knee in vertebrates (the other being the fibula, behind and to the outsi ...

is irritated with the examiners knuckles.
see video
* Schäffer's phenomen: The

Achilles tendon The Achilles tendon or heel cord, also known as the calcaneal tendon, is a tendon at the back of the lower leg, and is the thickest in the human body. It serves to attach the plantaris, gastrocnemius (calf) and soleus muscles to the calcane ...

is kneaded''.'' * Gordon's phenomen: The triceps surae muscle ''is kneaded.''

Flexion

These phenomena are positive if the toes of the foot flex: * Rossolimo – The ball of the foot is struck using a tendon hammer.
see video

Clinical significance

Pyramidal signs can be a result from different types of damage to the brain or spinal cord, such as strokes, infections, tumors, hemorrhagic events, multiple sclerosis, or trauma. Parkinsonian-Pyramidal syndrome (PPS) is a combination of both pyramidal and parkinsonian signs that manifest in various neurodegenerative diseases.

References

External links

Babinski sign
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