Anatomy
Summary
Lumbosacral radiculopathy arises from nerve root compression, often due to disc herniation or spondylosis. It can present with sensory deficits like numbness and tingling, motor deficits manifesting as weakness, and decreased deep tendon reflexes. Lumbar radiculopathies often occur at the L2-L4 nerve roots, as well as the L5 root. L2-L4 radiculopathy results in decreased sensation in the anterior thigh and medial shin, along with compromised hip flexion, hip adduction, and knee extension. It is also associated with a decreased patellar reflex. L5 radiculopathy affects sensation in the lateral shin and dorsum of the foot and impairs functions like foot dorsiflexion and toe extension.
Sacral radiculopathies most commonly involve S1 and S2-S4 nerve roots. S1 radiculopathy will typically cause diminished sensation to the posterior calf, lateral, and sole of the foot, as well as hinder foot plantarflexion. It also associated with a decreased achilles reflex. S2-S4 radiculopathies can lead to bladder and bowel incontinence, sexual dysfunction, and decreased sensation to the perineum, including a diminished anocutaneous reflex. Cauda equina syndrome is a severe condition manifesting as saddle anesthesia, bladder/bowel incontinence, and lower extremity weakness, along with absent patellar and achilles reflexes.
Lesson Outline
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FAQs
The lumbosacral plexus is a network of nerve fibers located in the lower spine that form the nerves that supply the lower body. They are responsible for the sensation and movement in the lower body, particularly affecting the hips, buttocks, legs, and feet.
L2-L4 and L5 radiculopathy are both conditions where one or several nerve roots are compromised but are distince in the location of damage and symptoms. L2-L4 radiculopathy affects the front of the thighs down to the knees, whereas L5 radiculopathy affects the area from the buttocks, down the lateral and posterior part of the leg, and into the big toe. The symptoms can include pain, numbness, tingling, and weakness associated with these regions.
For S1 radiculopathies, the sensory symptoms often involve decreased sensation in the posterior calf as well as the lateral and sole aspects of the foot. On the motor front, patients may experience difficulty in plantarflexing the foot and walking on their tiptoes. Additionally, the achilles reflex may be weakened or absent. In S2-S4 radiculopathies, there are a wide rand of implications including bladder and bowel incontinence, and sexual dysfunction. Sensory loss is often localized to the perineum, and the anocutaneous reflex, commonly known as the "anal wink," may be diminished or absent.
Cauda equina syndrome is a medical emergency that occurs when the bundle of nerve roots at the lower end of the spinal cord becomes compressed. This compression can lead to a cascade of symptoms, ranging from 'saddle anesthesia', or loss of sensation around the inner thighs and buttocks, to bladder and bowel incontinence. In addition, patients may experience pronounced weakness in the lower extremities and an absence of reflexes such as the patellar and achilles reflexes.
