Introduction ..• Fibers of the corticospinal tract arise as axons of pyramidal cells in the fifth layer of the cortex.• It conducts motor impulses from the brain to the spinal cord where somatic motor neurons conduct impulses to various skeletal muscle effectors.
Anatomy ..• The descending fibers originated in the primary motor cortex pass via the corona radiata and then pass through the interior capsule.• On entering the pons, the tract is broken into many bundles.
Anatomy ..• In the medulla oblongata, the bundles become grouped together to form swelling known as pyramid.
Anatomy ..• At the junction of the medulla oblongata and spinal cord, most of fibers cross the midline at the decussation of the pyramids and enter the lateral white column of the spinal cord to form the lateral corticospinal tract.
Anatomy ..• The remaining fibers do not cross in the decussation but descend in the anterior white column of the spinal cord as the anterior corticospinal tract.• The lateral corticospinal tract descends the length of the spinal cord; its fibers terminate in the anterior gray column of the all spinal cord segments.
Corticospinal tract syndrome ..• It’s known as upper motor neuron syndrome.• This syndrome will change the motor control of skeletal muscles.• The changes vary depending on the site and the extent of the lesion.
Causes of Corticospinal tract syndrome ..• Stroke• Multiple sclerosis• Traumatic spinal injury• Cerebral palsy Leading to many changes ..
Corticospinal tract syndrome ..• The changes may includes: ▫ Muscle weakness ▫ Decrease motor control including decrease speed and accuracy ▫ Spasticity ▫ Babinski sign and Ankle clonus is present ▫ Deep tendon reflexes are increased or present ▫ Clasp-knife response ( initial higher resistance to movement is followed by a lesser resistance )
Corticospinal tract syndrome ..• Treatment : ▫ Physiotherapy ( exercise, serial casts, flexibility exercises, … ) ▫ Equipments that help in movement ▫ Medical intervention ( baclofen, diazepam, dantrolene, phenol injections )