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 Weakness is a symptom of a number of different conditions. The causes are many and can be divided into conditions that have true or perceived muscle weakness. True muscle weakness is a primary symptom of a variety of skeletal muscle diseases, i ...

, slowing of rapid alternating movements,

hyperreflexia Hyperreflexia is overactive or overresponsive bodily reflexes. Examples of this include twitching and spastic tendencies, which indicate upper disease of the upper motor neurons and the lessening or loss of control ordinarily exerted by highe ...

, and a positive

Babinski sign The plantar reflex is a reflex elicited when the sole of the foot is stimulated with a blunt instrument. The reflex can take one of two forms. In healthy adults, the plantar reflex causes a downward response of the hallux (flexion). An upward re ...

. The presence of these phenomena is nearly always connected with ''

'' and some authors think that we can not count them as a pathological reactions at all. Their existence on lower extremity is more serious that on the upper ones. The most common reason for irritative phenomena is a lesion of a central motoneuron, but in the presence of asymmetrical findings then a diagnosis of

amyotrophic lateral sclerosis Amyotrophic lateral sclerosis (ALS), also known as motor neuron disease (MND) or Lou Gehrig's disease, is a neurodegenerative disease that results in the progressive loss of motor neurons that control voluntary muscles. ALS is the most comm ...

should be considered. 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 t ...

s from the

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

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

brain A brain is an organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It is located in the head, usually close to the sensory organs for senses such as vision. It is the most complex organ in a v ...

and

spinal cord The spinal cord is a long, thin, tubular structure made up of nervous tissue, which extends from the medulla oblongata in the brainstem to the lumbar region of the vertebral column (backbone). The backbone encloses the central canal of the spi ...

and help in controlling voluntary movement of

muscle Skeletal muscles (commonly referred to as muscles) are organs of the vertebrate muscular system and typically are attached by tendons to bones of a skeleton. The muscle cells of skeletal muscles are much longer than in the other types of muscl ...

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 Toes are the digits (fingers) of the foot of a tetrapod. Animal species such as cats that walk on their toes are described as being '' digitigrade''. Humans, and other animals that walk on the soles of their feet, are described as being '' pl ...

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. Endosteum lines the inner surface of the medullary cavity of all long bones. Structure ...

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

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 calcaneus (h ...

is kneaded''.'' * Gordon's phenomen: The

triceps surae muscle The triceps surae consists of two muscles located at the calf – the two-headed gastrocnemius and the soleus. These muscles both insert into the calcaneus, the bone of the heel of the human foot, and form the major part of the muscle of the pos ...

''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

Parkinsonian-Pyramidal syndrome (PPS) is a combination of both pyramidal and parkinsonian signs that manifest in various neurodegenerative diseases.

References

External links

Babinski sign
* *