spine and spinal cord Flashcards
Paresthesia
Abnormal sensation- burning, pricking, tickling or tingling.
Dysesthesia
impairment of sensation of short anesthesia
Paresis,
decreased strength
plegia
complete loss of strength
Dermatome,
cutaneous area served by individual sensory root
Myotome
Muscles innervated by an individual motor root
Radiculopathy,
sensory and/or motor dysfunction due to injury to a nerve root
Myelopathy
disorder resulting in spinal cord dysfunction
spinothalamic/anterolateral tract - function and where it crosses
pain and temperature, crosses 2-3 segments above root entry level in anterior spinal cord
posterior columns function and where it crosses
vibration and position, crosses in medulla
corticospinal tract function and where it crosses
motor, crosses in lower medulla
Know where the nerve roots exit
C1, 2, 3, 4, 5, 6, 7 roots exit above same numbered vertebra (e.g. C7 above C7). C8 below C7 and all other roots exit below same numbered vertebra (e.g. T1 exits below T1).
Know the spinal cord level that each vertebral body overlies (C6 bone overlies C7 cord.)
Upper cervical: vertebra # overlies same cord segment # (C2 bone, C2 cord) o Lower cervical: vertebra # overlies cord segment # + 1 (C6 bone, C7 cord) o Upper thoracic: vertebra # overlies cord segment # + 2 (T4 bone, T6 cord)
o Lower thoracic/lumbar: vertebra # overlies cord
segment # +2- 3 (T 11bone, L1-2 cord) o Lower edge of the L1 vertebral body overlies the cord tip (conus medullaris)Upper cervical: vertebra # overlies same cord segment # (C2 bone, C2 cord) o Lower cervical: vertebra # overlies cord segment # + 1 (C6 bone, C7 cord) o Upper thoracic: vertebra # overlies cord segment # + 2 (T4 bone, T6 cord)
o Lower thoracic/lumbar: vertebra # overlies cord
segment # +2- 3 (T 11bone, L1-2 cord) o Lower edge of the L1 vertebral body overlies the cord tip (conus medullaris)Upper cervical: vertebra # overlies same cord segment # (C2 bone, C2 cord) o Lower cervical: vertebra # overlies cord segment # + 1 (C6 bone, C7 cord) o Upper thoracic: vertebra # overlies cord segment # + 2 (T4 bone, T6 cord)
o Lower thoracic/lumbar: vertebra # overlies cord
segment # +2- 3 (T 11bone, L1-2 cord) o Lower edge of the L1 vertebral body overlies the cord tip (conus medullaris)Upper cervical: vertebra # overlies same cord segment # (C2 bone, C2 cord) o Lower cervical: vertebra # overlies cord segment # + 1 (C6 bone, C7 cord) o Upper thoracic: vertebra # overlies cord segment # + 2 (T4 bone, T6 cord)
o Lower thoracic/lumbar: vertebra # overlies cord
segment # +2- 3 (T 11bone, L1-2 cord) o Lower edge of the L1 vertebral body overlies the cord tip (conus medullaris)
somatotopic organization of tracts
Posterior columns: sacral medial, arms lateral. Spinothalamic and corticospinal: sacral lateral, arms medial
blood supply to spinal cord
2 posterior spinal arteries supply posterior columns, 1 anterior spinal artery supplies spinothalamic and corticospinal tracts. Gray matter requires more blood than white matter
Recognize the symptoms of a radiculopathy and
radiculopathy: dz affecting nerve roots. Pain
Lhermitte’s sign, Spurling’s sign (+foraminal compression test), Lasegue’s sign (+straight leg raising test, SLR). Paresthesia (abnl sensations), Sensory loss (hypoesthesia, anesthesia), Weakness (paresis, plegia), loss of fine motor control, Disorders of Bowel, bladder, or sexual dysfunction, Gait problems LMN signs. Relieving factors rest, graded therapy, NSAIDs, muscle relaxants. radiculopathy: dz affecting nerve roots. Pain
Lhermitte’s sign, Spurling’s sign (+foraminal compression test), Lasegue’s sign (+straight leg raising test, SLR). Paresthesia (abnl sensations), Sensory loss (hypoesthesia, anesthesia), Weakness (paresis, plegia), loss of fine motor control, Disorders of Bowel, bladder, or sexual dysfunction, Gait problems LMN signs. Relieving factors rest, graded therapy, NSAIDs, muscle relaxants. radiculopathy: dz affecting nerve roots. Pain
Lhermitte’s sign, Spurling’s sign (+foraminal compression test), Lasegue’s sign (+straight leg raising test, SLR). Paresthesia (abnl sensations), Sensory loss (hypoesthesia, anesthesia), Weakness (paresis, plegia), loss of fine motor control, Disorders of Bowel, bladder, or sexual dysfunction, Gait problems LMN signs. Relieving factors rest, graded therapy, NSAIDs, muscle relaxants. radiculopathy: dz affecting nerve roots. Pain
Lhermitte’s sign, Spurling’s sign (+foraminal compression test), Lasegue’s sign (+straight leg raising test, SLR). Paresthesia (abnl sensations), Sensory loss (hypoesthesia, anesthesia), Weakness (paresis, plegia), loss of fine motor control, Disorders of Bowel, bladder, or sexual dysfunction, Gait problems LMN signs. Relieving factors rest, graded therapy, NSAIDs, muscle relaxants.
understand Lhermitte’s symptom.
Neck flexion results in “electric shock” sensation down the back and/or into arms. Attributed to posterior column disease (MS, disc, B12 def, mass).
spurlings sign
narrow foramen causes constriction of nerves exiting at that level
lasegues sign
straight leg sign- sretch sciatic nerve and shooting radicular pain occurs
Causes of radiculopathies
Common causes: Compression by degenerative joint disease (causing bony proliferation) or herniated disc near intervertebral foramen. Remember, discs can
herniate laterally. Posterior herniation would cause myelopathy. Less common causes: herpes zoster (shingles), carcinoma, lymphoma, sarcoidosis.Common causes: Compression by degenerative joint disease (causing bony proliferation) or herniated disc near intervertebral foramen. Remember, discs can
herniate laterally. Posterior herniation would cause myelopathy. Less common causes: herpes zoster (shingles), carcinoma, lymphoma, sarcoidosis.Common causes: Compression by degenerative joint disease (causing bony proliferation) or herniated disc near intervertebral foramen. Remember, discs can
herniate laterally. Posterior herniation would cause myelopathy. Less common causes: herpes zoster (shingles), carcinoma, lymphoma, sarcoidosis.
Know the neurologic signs used to distinguish lesions affecting the lower motor neurons versus those affecting the upper motor neurons.
LMN: atrophy, fasciculation, flaccidity, decreased DTRs and flexor plantar response. UMN: immediate muscle weakness and hypotonia, hyporeflexia followed by normal muscle bulk, no fasciculations, spasticity, increased DTRs, extensor or babinski plantar response
spinal shock
acute complete spinal cord transection. Has upper motor neuron damage signs. Acutely: Exam shows flaccid weakness, absent tone, absent DTR, & absent autonomic function (bladder, sweat). By 3-4 months: Exam shows UMN spastic weakness, hyperactive DTRs, Babinski sign.acute complete spinal cord transection. Has upper motor neuron damage signs. Acutely: Exam shows flaccid weakness, absent tone, absent DTR, & absent autonomic function (bladder, sweat). By 3-4 months: Exam shows UMN spastic weakness, hyperactive DTRs, Babinski sign.acute complete spinal cord transection. Has upper motor neuron damage signs. Acutely: Exam shows flaccid weakness, absent tone, absent DTR, & absent autonomic function (bladder, sweat). By 3-4 months: Exam shows UMN spastic weakness, hyperactive DTRs, Babinski sign.
symptoms of cervical stenosis
Can result in UMN signs in legs +/- bladder dysfunction.
Complete cord transection tracts, deficit
Tracts: All ascending sensory & descending
motor/autonomic tracts. Deficit: Sensory + motor levels below lesion; may also have root signs at site. Note: Spinal shock followed by UMN signs.Tracts: All ascending sensory & descending
motor/autonomic tracts. Deficit: Sensory + motor levels below lesion; may also have root signs at site. Note: Spinal shock followed by UMN signs.Tracts: All ascending sensory & descending
motor/autonomic tracts. Deficit: Sensory + motor levels below lesion; may also have root signs at site. Note: Spinal shock followed by UMN signs.
central lesion tracts,examples, deficit
Tracts: Initially involve crossing ST. E.g.s: Syringomyelia (fluid-filled cavity in cord), ependymomas, cord contusion. Deficit: PP/Temp loss at level of lesion, with
sparing of position sensation. Note: Cape-like distribution if in C-spine.Tracts: Initially involve crossing ST. E.g.s: Syringomyelia (fluid-filled cavity in cord), ependymomas, cord contusion. Deficit: PP/Temp loss at level of lesion, with
sparing of position sensation. Note: Cape-like distribution if in C-spine.Tracts: Initially involve crossing ST. E.g.s: Syringomyelia (fluid-filled cavity in cord), ependymomas, cord contusion. Deficit: PP/Temp loss at level of lesion, with
sparing of position sensation. Note: Cape-like distribution if in C-spine.
Posterior column syndrome tracts, examples, and deficit
Tracts: PC. E.g.s. Tabes dorsalis (form of neurosyphilis)
Deficit: Bilateral loss of position & vibration sensationTracts: PC. E.g.s. Tabes dorsalis (form of neurosyphilis)
Deficit: Bilateral loss of position & vibration sensationTracts: PC. E.g.s. Tabes dorsalis (form of neurosyphilis)
Deficit: Bilateral loss of position & vibration sensation
Combined Anterior Horn Cell-Pyramidal Tract
Syndrome tracts, examples, deficitCombined Anterior Horn Cell-Pyramidal Tract
Syndrome tracts, examples, deficitCombined Anterior Horn Cell-Pyramidal Tract
Syndrome tracts, examples, deficit
Tracts: Cortico Spinal and LMN cells in cord. E.g.s: Amyotrophic lateral sclerosis (Lou Gehrig’s disease). Deficit: Loss of bilateral strength. Note: Fasciculations, atrophy, decreased or increased DTR, normal sensation.
Brown-Sequard (Hemi-Section) tracts, eg, deficit
Tracts: Crossed ST + uncrossed PC + crossed CS. E.g.: Compression by herniated discs, tumor extramedullary abscess, etc. Deficit: Below lesion, loss of CL PP/Temp, IL Position, IL strength.
Posterolateral Column Syndrome tracts, eg, deficit
Tracts: PC + CS. E.g.: B12 deficiency (aka subacute combined degeneration). Deficit: Bilateral loss of position & vibration, and strength.
anterior horn cell syndrome tracts, eg, deficit
Tracts: None - lower motor neuron (cell). E.g.: Spinal muscular atrophy, polio virus. Deficit: Bilateral loss of strength. Note: Fasciculations, decrased tone + decreased DTRs with sparing of all sensory tracts and bladder functions
Anterior Spinal Artery Occlusion tracts, eg, deficit
Tracts: ST + CS. E.g.: Anterior spinal artery occlusion.
Deficit: Bilateral loss of strength + PP/Temp, with sparing position senseTracts: ST + CS. E.g.: Anterior spinal artery occlusion.
Deficit: Bilateral loss of strength + PP/Temp, with sparing position senseTracts: ST + CS. E.g.: Anterior spinal artery occlusion.
Deficit: Bilateral loss of strength + PP/Temp, with sparing position sense
Pyramidal Tract Syndrome tracts, eg, deficit
Tracts: CS. E.g.: Primary lateral sclerosis. Deficit: Bilateral UMN weakness with spastic gait,increased DTRs, but complete sparing of all sensory tracts and bladder function.
Myelopathy with radiculopathy tracts, egs, deficit
Tracts: Any or all 3 tracts (esp. CS). E.g.s: Cervical spinal stenosis, may be congenital or degenerative. Deficit: Bilateral UMN syndrome with spastic gait, increased DTRs + IL or CL root signs + possible bladder dysfunction.
Know how to distinguish conus medullaris syndrome from cauda equina syndrome.
Conus medullaris (cord tip, S2-S5): late pain in thighs and buttocks, pelvic floor weakness, symmetric saddle anesthesia numbness, early bladder dysfunction, early bowel and sexual dysfunction. Cauda equina (roots L1-S5): early root pain radiating to legs, leg weakness and decreased DTRs (LMN), patchy assymetric saddly, late bladder dysfunction, late bowel and sexual dysfunction.
Understand the basic neural pathways involved in the control of micturition
Parasympathetic nerve fibers from S2, S3 and S4 innervate the detrusor muscle; activation of the parasympathetic nervous system results in detrusor muscle contraction and micturition. sympathetic activation inhibits detrusor contraction and reduces tension in the smooth muscle of the bladder neck and proximal urethra, preventing micturition Motor innervation of the bladder, pelvic floor, and urethral sphincter arises from segments S2 to S4 of the spinal cord. Sensations of bladder fullness or stretch are conveyed through long neurons from the periaqueductal gray in spinal cord to the pons. A reflex pathway in interomediolateral column from Tll-L1 is immediately activated resulting in constriction of internal urethral sphincter and decreases parasympathetic firing.
Understand the sensory territory, unique motor territory, and reflex components of the C5,C6,C7 and L4,L5,S1 nerve roots, as presented in this lecture.
C5: deltoid, infraspinatus and biceps motor. Shoulder, upper lateral arm sensory. Biceps reflex. C6: wrist extensors and biceps motor. 1st and 2nd digits of hand sensory. Biceps and brachioradialis reflex. C7: triceps motor, 3rd digit sensory, triceps reflex. L4: psoas and quads motor, knee and medial leg sensory, patellar reflex. L5: foot dorsiflexion, big toe extension, foot eversion and inversion motor, dorsum of foot and great toe sensory, no reflexes. S1: foot plantarflexion motor, lateral foot, small toe and sole of foot sensory, achilles reflex
Lsion to parasympathetic lower motor neurons- effect on micturition
weakness, atrophy, and hyporeflexia. The bladder does not contract and, if the sensory afferents are affected, no sensation of a full bladder will be perceived. If sensation is intact, but the motor efferents are affected, then there is an urge to void but good detrussor contraction is not possible. Lower motor lesions can occur anywhere from the preganglionic parasympatetic neurons at S2, S3 and S4 (whose cell bodies are located in the conus medullaris), the sacral roots in the cauda equina, the pelvic nerve, the pelvic plexus, or the
second order, postganglionic parasympathetic neuron that innervates the detrussorweakness, atrophy, and hyporeflexia. The bladder does not contract and, if the sensory afferents are affected, no sensation of a full bladder will be perceived. If sensation is intact, but the motor efferents are affected, then there is an urge to void but good detrussor contraction is not possible. Lower motor lesions can occur anywhere from the preganglionic parasympatetic neurons at S2, S3 and S4 (whose cell bodies are located in the conus medullaris), the sacral roots in the cauda equina, the pelvic nerve, the pelvic plexus, or the
second order, postganglionic parasympathetic neuron that innervates the detrussor
Lesion to descending pathways (C2) -effect on bladder control
UMN lesion- must be bilateral to affect bladder. If bilateral lesion of spinal cord at C2, detrusor becomes flaccid (retention), overflow incontinence. Over time, spasticity develops (bladder contracts with small degrees of stretch), frequncy and urgency,
List the nucleus location and nerve roots and result of injury for detrusor and urethral afferents
DRG S2, S3, S4, nerve roots S2, S3, S4, loss of sensation of filling, overflow incontinence
List the nucleus location and nerve roots and result of injury forsomatic innervation of urethral sphincter
Onuf’s nucleus (alpha motorneurons in ventral horn), S3, S4, loss of voluntary control, rarely injured in isolation
List the nucleus location and nerve roots and result of injury to somatic innervation of pelvic floor muscles
anterior horn cells, S2, S3, S4, loss of voluntary control over full bladder
List the nucleus location and nerve roots and result of injury for PSNS innervation of detrusor
sacral parasympathetic nucleus, S2, S3, S4, flaccid areflexic bladder, overflow incontinence
List the nucleus location and nerve roots and result of injury forsympathetic innervation of bladder neck, dome and urethra
interomediolateral cell column, T11, T12, L1, variable, can result in loss of internal sphincter control, rarely isolated event
List the nucleus location and nerve roots and result of injury for coordinated action of lower centers
Descending fibers from frontal cortex and brainstem
control centers, Fibers on medial aspect of LCST, UMN phenomenon: initially flaccid, later spastic bladder. Lack of coordinated response of detrusor andDescending fibers from frontal cortex and brainstem
control centers, Fibers on medial aspect of LCST, UMN phenomenon: initially flaccid, later spastic bladder. Lack of coordinated response of detrusor and
List the nucleus location and nerve roots and result of injury for medial frontal cortex (frontal micturition inhibiting area)
n/a, Fibers on medial aspect of LCST, Urge incontinence
Which nerves are involved in the DTRs: biceps, brachioradialis, tricepts, fingers, quadriceps, achilles
DTRs: Arm: Biceps (C5, C6), Brachioradialis (C6, C7), Triceps (C6,C7), Fingers (C8). Leg: Quadriceps (L3, L4), Gastrocnemius (Achilles reflex, S1).
abdominal reflex
elicited by drawing a line away from the umbilicus along the diagonals of the 4 abdominal quadrants. A normal reflex draws the umbilicus toward the direction of the line that is drawn
cremasteric reflex
•elicited by drawing a line along the medial thigh and watching the movement of the scrotum in the male. A normal reflex results in elevation of the ipsilateral testis.
The anal wink reflex
reflex elicited by gently stroking the perianal skin with a safety pin. It results in puckering of the rectal orifice owing to contraction of the corrugator-cutis-ani muscle.
Know the thoracic dermatomes that typically cover the nipple line, xyphoid, and umbilicus.
Nipple: T4. Umbilicus: T10. Xiphoid: T5-T6
Hoffmans sign
holding the patient’s middle finger loosely and flicking the fingernail downward, causing the finger to rebound slightly into extension. If the thumb flexes and adducts in response, Hoffmann’s sign is present. Hoffmann’s sign, or heightened finger flexor reflexes suggest an upper motor neuron lesion affecting the hands.
Babinski’s sign
Babinski’s sign is associated with upper motor neuron lesions anywhere along the corticospinal tract. Test the plantar response by scraping an object across the sole of the foot beginning from the heel, moving forward toward the small toe, and then arcing medially toward the big toe. The normal response is downward contraction of the toes. The abnormal response, called Babinski’s sign, is characterized by an upgoing big toe and fanning outward of the other toes.
reinforcement procedures for reflexes
If you cannot elicit a reflex, you can sometimes bring it out by certain reinforcement procedures. For example, have the patient gently contract the muscle being tested by raising the limb very slightly, or have them concentrate on forcefully contracting a different muscle group just at the moment when the reflex is tested.
Understand ALL of the material presented in neuroexam.com under “reflexes” (except the material on “reflexes tested in special situations”).
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Learning objectives from the Spinal cord powerpoint exercise from last exam.
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