Cervical and low back pain and radiculopathy,Jenice Robinson, MD Assistant Professor of Neurology Penn State College of Medicine NBS725 January 12, 2009,Learning Objectives:,After reviewing the content of the lecture, the student will be able to: 1) Distinguish somatic and radicular neck and low back pain by mechanism of pain and by associated clinical symptoms and signs 2) Describe the anatomy of the ventral and dorsal nerve roots, the location of the cell bodies in the ventral horn and dorsal root ganglia, and the formation of the spinal nerves 3) List common symptoms and signs of cervical and lumbosacral disk herniation causing nerve root compression 4) Draw the anatomy of the nerve roots at the L4-L5 and L5-S1 levels and demonstrate how a disk herniation at these levels may compress the nerve roots 5) Describe diagnostic imaging methods for use to evaluate radicular pain 6) Describe basic treatment of radiculopathy caused by disc herniation 7) List red flags in the evaluation of neck and low back pain indicating increased risk for a possible serious underlying cause of the pain,Back and neck pain:,Very common Up to 50% of working adults have had a back injury in the past year Back symptoms most common cause of disability in patients $20 billion dollars per year,Somatic pain:,Most cervical and low back pain fall into the category of somatic pain Somatic pain arises from the stimulation of A (small myelinated) and C (unmyelinated) nociceptive nerve endings Activation can be chemical via tissue damage Direct mechanical stimulation,Pain sensitive structures:,Muscles Ligaments,Pain sensitive structures:,Muscles Ligaments Facet joints (zygapophyseal) Dura mater Intravertebral discs: annulus fibrosis Epidural veins,Somatic pain:,Aching/expanding pressure Felt locally in area of injury, but also my be referred to other areas Referred to areas innervated by the same spinal cord segment Mechanism is convergence in spinal cord and thalamus Afferents from the primary source of pain converge with afferents from the site of referral,Referred pain from stimulation of zygapophyseal joints,Somatic pain: Summary,Aching/pressure quality Occurs in broad areas reflecting areas of referral from the same spinal segment, severe could radiate to limbs Otherwise known as back strain and etc. Does NOT: Travel in bands Have a lancinating or electric shock quality Have associated neurologic signs on examination,Radicular pain:,Less common than somatic pain The hallmark of radiculopathy, any pathologic condition affecting the nerve roots Arises from the nerve roots or dorsal root ganglia Herniated disk is by far the most common cause,Radicular pain:,Inflammation is important as a pain mechanism: Phospholipase A and E, NO, TNF, other pro-inflammatory mediators are released by a herniated disk The dura surrounding the ventral and dorsal nerve root is bathed in this exudate Inflammation or prior injury to nerve root is necessary to cause compression to generate continued pain,dura,Radicular pain:,Lancinating or electric quality Moves in bands and usually radiates down the limbs Associated symptoms of paresthesias are very helpful determining the identity of the involved nerve root better than site of pain Symptoms of weakness and objective findings of sensory loss, weakness and reflex loss may occur,Dermatome,Each nerve root supplies cutaneous sensation to a specific area of skin, known as a dermatome,Overlaps somewhat, so wont lose All sensation, but will feel paresthesia,Myotome,If radicular pain sever could affect myotome Each nerve root supplies motor innervation to certain muscles, known as a myotome,Types of peripheral nerve injury:,Neurapraxia: Segmental loss of myelin coating on nerve root/nerve Weakness, but no atrophy Axonotmesis: Loss of axons and myelin but at least some supporting structures are preserved Weakness and muscle atrophy if severe Neurotmesis: Loss of axons, myelin, and complete disruption of supporting structures (transection) weakness and atrophy,Radiculopathy: Summary,Pain and paresthesias radiating in the distribution of a nerve root, often associated with sensory loss and paraspinal muscle spasm Sensory loss (often vague or ill defined) Weakness (often subjective, not present, or mild) Reflex loss (may be present or absent),Radiculopathy: Provocative maneuvers,Valsalva Cough, laughter, voluntary contraction of abdominal wall muscles, when straining, make radicular pain worse Stretching the involved nerve rootL1S1sitting worsens, C5C6abduct arm over head relieves Straight leg raiseL5L6 worsens,Reflexes:,C5-C6 Biceps C5-C6 Brachioradialis C7 Triceps L3-L4 Quadriceps/patellar S1 Ankle,60sno ankle jerkscould be normal if on both sides, but if only on one side With pertinent symptoms on that side-significant,In the cervical spine: Nerve roots exit above their named vertebral body I.e., C7 exits below C6 and above C7-so lateral disk herniation here gets C7 In the lumbar spine: Spinal cord ends at L1 or L2 Nerve roots travel long distances then exit below their named vertebral body The lumbosacral nerve roots are susceptible to injury at multiple locations T11-L1anterior horn,