Transection of Spinal cord

Effects of complete transection of spinal cord

• Spinal cord injury can occur during accidents
• Injury leading to complete transection of spinal cord shows features such as
• Immediate and permanent loss of all voluntary movements below the level of injury
• Immediate loss of all reflexes below the level of injury
• Permanent loss of all sensations below the level of injury

There are three stages of spinal injury with complete transection

1. Stage of spinal shock
2. Stage of reflex activity
3. Stage of reflex failure

Stage of spinal shock

• Loss of reflexes due to the removal of supraspinal influences.
• Loss of voluntary muscle power.
• All sensations below the level of leasion are lost.
• Sharp fall in blood pressure due to vasomotor paralysis and circulation becomes sluggish
• Overling skin and subcutaneous tissue suffer lack of nutrition and are prone to  develop bedsores.
• Urinary bladder muscles become hypotonic or atonic
• Bowel becomes hypotonic.

Stage of reflex activity

• After a lapse of 2 weeks, the tone of flexor muscle returns, give rise to paraplegia in flexion.
• Babinski’s sign becomes positive.
• Tendon jerk begins to appear.
• Mass reflex may appear.
• Bladder becomes automatic.

Stage of reflex failure

• Degeneration of spinal cord and intercurrent infections cause failure to reflex activities.
• Once again the muscle become hypotonic, mass reflexes disappear and the patient dies.

Effects of Hemisection of Spinal cord (Brown Sequard Syndrome)

Above the level of lesion

• The zone of hyperesthesia limited to one segment.

At the level of lesion on the same side

Sensory changes

• Loss of all sensations (fine touch, pressure, pain, temperature, vibration)

Motor changes

• Lower motor neuron type of paralysis.

Below the level of lesion

Sensory changes

• Pain and temperature sensations lost on the opposite site.
• Position sense, fine touch and vibration sense lost on the same side.

Motor chages

• The upper motor neuron type of p aralysis on the same side because of damage to the corticospinal tract.
• On the opposite side, there is minimal motor paralysis following damage to the anterior corticospinal tract.

Applied Aspects

Poliomyelitis

• It is an acute infectious disease characterized by local or widespread muscular paralysis.
• It is produced by a virus causing destruction of anterior horn cells of the spinal cord or the corresponding cell in the medulla.

Facial palsy

• It is produced due to the damage of faceial nerve
• There are three types of facial palsy
• Supranuclear
• Nuclear
• Infranuclear

In the supranuclear type, one side of the face is affected (unilateral), but the upper part of the face is spared due to bilateral innervation

Voluntary movements of facial muscles are affected by emotional expressions are intact

Innucear and infranuclear types, one half of the face is affected.

It may be unilateral or bilateral

There is no impairment of taste sensation

Features of nuclear and infracuclear types of facial palsy

• Facial muscles are paralysed on one side.
• The eye cannot be closed completely and palperbral fissure is widened. Tears collect in the eye and tend to overflow which is called Epiphora.
• Whenever the individual tries to close the eye, the eyball rolls upward under a partly covered eyelid. This is known as Bells’ phenomenon.
• The angle of the mouth is drooping on the affected side and the other agle gets deviated to the normal side.
• Nasolabial fold is lost on the affected side.