Symptoms will follow a dermatomal distribution
|Herniated disk, also referred to as herniated nucleus pulposus (HNP), is a structural deterioration of the intervertebral discs that provide shock absorption for the spine. Also known as "slipped disc," damage to the disc enables the nucleus pulposus to seep through the torn or stretched annulus and bulge outward between the vertebrae. HNP frequently occurs between L5-S1 or the fourth and fifth lumbar vertebrae. Causes of HNP include natural degeneration, spine trauma, and spinal stenosis. Assessment findings include radiating pain, lower extremity weakness, and bowel/bladder incontinence. Diagnostic studies to determine structural defects and locate damaged sites include x-rays, myelogram, MRI, and CT scan. Interventions for HNP include wearing a brace to support the spine. Medications include NSAIDs, opioids, analgesics, epidural corticosteroids, muscle relaxants, and antidepressants. Invasive procedures indicated for patients with HNP include intradiscal electrothermal plasty (IDET), interspinous process decompression, laminectomy, discectomy, spinal fusion, and artificial disc replacement.|
|The skin's surface is divided into specific areas called dermatomes, which are mainly supplied by a single spinal. There are 8 cervical nerves (C1 being an exception with no dermatome), 12 thoracic nerves, 5 lumbar nerves and 5 sacral nerves. Each of these nerves relays sensation (and pain) from a particular region of skin to the brain.|
Cervical herniated disk
- Usually posterolateral at C5-C6, C6-C7
- Young middle age mid 30's
- Cervical disk: Pain into the arm/shoulder pain, numbness and tingling pain into the arm with pain at rest – versus rotator cuff no pain at rest unless there is movement
- MRI is confirmatory – soft collar, NSAIDS, muscle relaxants, epidural steroid injections, surgical consultation if not responsive to conservative treatments
- May affect the levator scapular and trapezius muscles, resulting in weakness in shoulder elevation. There is no reliable associated reflex.
- Weakness of the rhomboid, deltoid, bicep, and infraspinatus muscles. Patients may have weakness of shoulder abduction and external rotation. The bicep reflex may be diminished.
- Affects the C6 nerve root and produces pain at the shoulder tip and trapezius with radiation to the anterior upper arm, radial forearm, and thumb, and sensory impairment in these areas. C6 radiculopathy can easily be confused for C5 or C7 radiculopathy. Weakness can overlap with the C5 or C7 muscles. Muscles affected include infraspinatus, bicep, brachioradialis, pronator teres, and triceps. Weakness involves flexion at the elbow, or shoulder external rotation. The bicep or brachioradialis reflex may be diminished.
- Affects the C7 nerve root and produces pain at the shoulder blade, pectoral area, and medial axilla with radiation to posterolateral upper arm, dorsal elbow and forearm, index and medial digits or all of the fingers, and sensory impairment in these areas. C7 radiculopathy can result in weakness of the triceps, pronator teres, flexor carpi radialis. Weakness involves the elbow extensors and forearm pronators. There may be a diminished triceps reflex.
- Causes C8 radiculopathy. Weakness can be present in the opponens pollicis, flexor digitorum profundus, flexor pollicis longus, and hand intrinsic muscles. Clinically, patients present with symptoms similar to an ulnar or median motor neuropathy and can have weakness of finger abductors and grip strength; they may also have findings suggesting median motor neuropathy. No reliable reflex test is available.
|Disk space||Nerve root||Muscle||Reflex||Sensory|
|C4-5||C5||Deltoid, supraspinatus, infraspinatus||Biceps||Lateral arm|
|C5-C6||C6||Biceps, wrist extensors||Biceps, brachioradialis||Radial forearm, thumb, index finger|
|C6-7||C7||Triceps, wrist flexors, finger extensors||Triceps||Middle finger|
|C7-T11||C8||Finger flexors||None||Fourth and fifth fingers|
|T1-2||T1||Finger abductors||None||Ulnar forearm|
Lumbar herniated disk
Diagnosis of Lumbar Disk Herniation
Pain in a dermatomal pattern - increases with coughing, straining, bending, and sitting
- L5-S1 is most common
- Also L4-L5
- Sciatica: back pain radiating through the thigh and buttocks - lower leg (below knee) down L5-S1 dermatome
- Physical Exam: + straight leg raise, + crossover test
- Noncontrast MRI is confirmatory
- NSAIDS, rest, steroids and physical therapy
- Epidural steroid injections
- Surgery if warranted
Look for "red-flag" symptoms:
- fecal incontinence
- Saddle anesthesia
- Urinary retention
- Intravenous drug use
- Unexplained fever
- Chronic steroid use
- progressive or disabling symptoms
- Focal neurologic deficit
- Fracture or infection
- Significant trauma at any age
- Older than 50 years, and mild trauma
- Neoplasm or fracture
- History of cancer (i.e., weight loss)
- Unexplained weight loss
- No improvement after six weeks of conservative management
Lumbar radiculopathy most commonly involves either the L5 or S1 root.
- Rare - symptoms involve pain, paresthesia, and sensory loss in the inguinal region.
- L2, L3, and L4
- In older patients with spinal stenosis. They are generally considered as a group because of marked overlap of innervation of the anterior thigh muscles. Acute back pain is the most common presenting complaint, often radiating around the anterior aspect of the thigh down into the knee.
- The most common radiculopathy affecting the lumbosacral spine. It often presents with back pain that radiates down the lateral aspect of the leg into the foot. On examination, strength can be reduced in foot dorsiflexion, toe extension, foot inversion, and foot eversion. Reflexes are generally normal.
- S2, S3, and/or S4
- Patients can present with sacral or buttock pain that radiates down the posterior aspect of the leg or into the perineum. Weakness may be minimal, with urinary and fecal incontinence as well as sexual dysfunction.
It usually involves the L5-S1 interspace
It typically involves anterior herniation of the nucleus pulposus
It usually requires surgical intervention
Treatment involves strict bed rest for 1 to 2 weeks
Forward flexion of the trunk often helps relieve symptoms