The pyramidal tract, also known as the corticospinal tract, is an important part of the central nervous system. It is responsible for all voluntary movements made by the body. Damage to this tract can lead to a number of problems, including paralysis, muscle weakness, loss of muscle control, and tremors.
The origins of the pyramidal tract lie in the “motor strip,” an area in the cerebral cortex where signals that trigger voluntary movement originate. A group of pyramidal neurons create a dense network of fibers that travels through the brain, along the brain stem, and into the spinal cord. Once in the spinal cord, the lower motor neurons connect with the nerves that innervate muscles all over the body.
When a voluntary movement is made, the signal is passed along from neuron to neuron along the corticospinal tract until it reaches the desired nerves. This transmission takes place in a fraction of a second, allowing people to respond in a way that may feel instantaneous. The level of control available through the pyramidal tract is extremely precise and highly detailed, allowing people to do everything from controlling the movement of the hands during brain surgery to running a marathon.
Certain neurological diseases can cause lesions in the pyramidal tract, leading to a loss of muscle control because nerves become damaged and can no longer transmit signals. The cells can also be damaged through stroke and trauma, such as a traumatic brain injury. Patients with pyramidal tract dysfunction are usually treated by a neurologist, a doctor who specializes in the treatment of diseases that involve the nervous system.
Patients who have sustained damage to their corticospinal tract have a prognosis that varies, depending on the nature of the damage. Some patients may be able to regain motor control over the course of the healing process. Others may permanently lose motor control, leading to the atrophy of muscles that are never used. Some patients can also develop issues like contractures, in which muscles or tendons become permanently shortened. Physical therapy can sometimes help patients retain muscle strength and control.
Problems with the pyramidal tract can be identified during a neurological examination in which a medical professional checks for classic signs, such as muscle weakness and the Babinski reflex, a reflex normally only seen in young children, and which is indicative of a problem when it is seen in adults.