Spinal Cord Disorders Flashcards
Clinical Signs of UPPER MOTOR NEURON LESIONS
Weakness?
Atrophy?
Atrophy vs weakness?
Fasciculations?
Muscle tone?
Muscle stretch reflexes?
Clonus?
Pathological reflexes/Babinski?
Clinical Signs of UPPER MOTOR NEURON LESIONS
Weakness - more diffuse
Atrophy - slight/general often from disuse
Atrophy vs weakness - SEVERE weakness with relatively little atrophy
Fasciculations - NEVER
Muscle tone - INCREASED (except spinal shock)
Muscle stretch reflexes- INCRASED (except spinal shock)
Clonus - can be present
Pathological reflexes/Babinski- PRESENT (except spinal shock)
Clinical Signs of LOWER MOTOR NEURON LESIONS
Weakness?
Atrophy?
Atrophy vs weakness?
Fasciculations?
Muscle tone?
Muscle stretch reflexes?
Clonus?
Clinical Signs of LOWER MOTOR NEURON LESIONS
Weakness - more focal
Atrophy- focal, SEVERE
Atrophy vs weakness - some strength may be present despite severe atrophy
Fasciculations - PRESENT
Muscle tone - DECREASED
Muscle stretch reflexes - DECREASED
Clonus - NEVER
Pathological reflexes/babinski- ABSENT
Intramedullary lesions:
Pain ?
Sensory Loss ?
Sacral Sparing ?
Intramedullary lesions:
Pain - diffuse or none
Sensory Loss - suspended
Sacral Sparing - PRESENT
UMN lesions symptoms found in a limb when a spinal cord lesion involves the _______ tract rostral/descending to the _______ cells that innervate the muscle of that limb
Found in the limbs ______ (ipsilaterla/contralateral) to the CST lesion in teh spinal cord or from ______ (ipsilateral/contralateral) of _____ tract involvement of the ______ or ______.
Where does the CST cross?
UMN lesions symptoms found in a limb when a spinal cord lesion involves the CORTICOSPINAL TRACT rostral/descending to the ANTERIOR HORN CELLS cells that innervate the muscle of that limb
Found in the limbs IPSILATERAL to the CST lesion in the spinal cord or from CONTRALATERAL of CORTICOSPINAL TRACT tract involvement of the BRAIN OR BRAIN STEM.
(CST crosses at the pyramids of the medulla!)
Lower motor neuron lesions signs found in a limb that has muscles innervated by _______ cells affected at _____ …
Lower motor neuron lesions signs found in a limb that has muscles innervated by ANTERIOR HORN CELLS affected AT THE LEVEL OF THE SPINAL CORD.
What path does the dorsal column pathway take?
ascend / descend?
Where do its primary fibers start and where does the first synapse occur?
What fibers does the DCT carry?
Receptors start at in the limbs (2-point discrimination, vibration, proprioception) –> travel up the fasciculus (gracilis or cuneatus) and synapse at the nucleus cuneatus —> 2nd order fibers CROSS at the level of the lower medulla as internal arcurate fibers to the medulla lemniscus –> travel up and synpase at teh VPL of the THALAMUS –> synapse at area 312 / post central gyrus / primary somatosensory cortex
Ascending sensory information, GSA
Lesion @ spinal cord –> ipsilateral deficits
Lesion @ cortex (ie-right cortex) –> wipe out vibration, pain, discrimination, etc on the contralateral side of the body (left)
Which DCT receptors are NOT encapsulated?
Free nerve endings, merkel’s disks, hair follicles
What is the function of the receptor:
Free Nerve Ending-
Merkel’s Disk-
Hair Follicle-
Meissner’s Corpuscle-
Pacinian Corpuscle -
Ruffinin Ending -
Joint Receptor -
Neuromucular Spindle -
Golgi Tendon Organs -
Free Nerve Ending- pain/temp
Merkel’s Disk- touch
Hair Follicle- touch
Meissner’s Corpuscle- 2 point discrimination
Pacinian Corpuscle - vibration
Ruffinin Ending - stretch/pressure
Joint Receptor - joint position
Neuromucular Spindle - limb muslce, stretch/length
Golgi Tendon Organs - muscle tension
Destruction of the dorsal columns (funiculi) could be caused by which infection?
What would be a tell-tale sign of this type of lesion?
Despite loss of ______, _____ remains intact.
Destruction of the dorsal columns (funiculi) could be caused by which infection? Syphilis –> neurosyphilis affecting to spinal cord, months to years after untreated syphilis. Lesion could occur at the dorsal roots and the dorsal spinal cord = TABES DORSALIS
What would be a tell-tale sign of this type of lesion?
positive ROMBERG sign = unsteady with eyes closed
[if patient is unstead with eyes open, then the cerebellum may be damaged]
Despite LOSS OF ALL SENSATION in lower limbs, and reflexes, radicular pain, DRG involvement (loss of pain and temp!!)
muscle strength remains intact (CST is spared = motor neurons intact)
Posterolateral Syndrome/Subacute Combined Degeneration:
Causes: (3)
What tracts are affected?
SX/tell-tale signs?
How can you differentiate subacute combined degen from tabes dorsalis?
Posterolateral Syndrome/Subacute Combined Degeneration:
Causes: Vitamin B12 deficiency (most common! alcoholics! –> demyelination of white matter), copper deficiency, HIV
What tracts are affected? DCT and lateral CST
SX/tell-tale signs? vibration and position loss (positive ROMBERG sign), spastic paraparesis (CST involvement = UMN signs, babinski sign)
How can you differentiate subacute combined degen from tabes dorsalis? Tabes also invovled the DRG, therefore in subacute combined degeneration syndrome, pain and temperature will NOT be affected, whereas this will be affected in tabes.
Corticospinal Tract / pyramidal tract.
What is the path CST travel? ascend/descend?
what are some signs/sx of a lesion to the CST?
What syndromes could affect CST?
What information is carried by the CST tract?
Corticospinal Tract / pyramidal tract:
Starts at precentral gyrus/betz cells or pyramidal cells of area 4 –> descends and travels to and through the internal capsule and form a major fiber that travels down the crus cerebri/cerebral peducle of the cerebrum - through middle pons - until getting to the pyramids of the medulla where the fibers CROSS – > travels as the lateral corticospinal tract ( 90%) to all levels - synapses in doral horn, IG, and ventral horn
what are some signs/sx of a lesion to the CST?
UPPER MOTOR NEURON signs - spacisity and some hemiplegia, positive babinski
What syndromes could affect CST?
subacute comb. degeneration, ant. spinal artery occlusion, ALS
What information is carried by the CST tract?
fine motor movements
Anterior Spinal Artery Occlusion:
Anterior spinal artery is supplied by several radicular branches of the aorta, midline, long orientation…supplies ____ (loc) of the spinal cord
Risk Factors for an artery occlusion:
Usually affects:
What tracts are affected?
What tracts are spared?
What are the presenting sx?
Anterior Spinal Artery Occlusion:
Anterior spinal artery is supplied by several radicular branches of the aorta, midline, long orientation…supplies 2/3 of the anterior/lateral the spinal cord
Risk Factors for an artery occlusion: atheroscleroitc disease of aorta, complication of AAA surgery, aortic disection of HTN pt
Usually affects: lower thoracic, upper lumbar SC
What tracts are affected? Lateral CST (fine motor movements), STT (pain and temp), dorsal/ventral SCT (unconscious proprioception/no clinical assessment)
What tracts are spared? DCT is spared = vibration and position NL
What are the presenting sx? SUDDEN, progressive symptoms, back pain, radicular pain; UMN signs in lower limbs, thoracic level sensory loss WITHOUT sacral sparing to pain and temperature
Spinothalamic Tract:
Where does it start - where does it travel?
What signs/sx could be present of an injury to the tract?
How are the fibers organized within the tract?
What lesions/sydromes affect the STT?
Pain and temp receptors in the skin relay info via the lateral division of hte dorsal root to the NUCLEUS PROPRIUS @ dorsal gray - STT starts at the nucleus prorprius (at all cord levels)–> fibers leave the gray, 2nd order fibers immediately cross via the anterior white commissure and travel up in the contralateral white matter, ascend in the lateral funiculus –> synpase on neurons in the ventral posterolateral nucleus of the VPL thalamus –> third order axons of the thalamus project to the primary sensory cortex area 312
Lesions to the STT in the spinal cord (or above) will affect pain and temperature sensation on the OPPOSITE side of the body
Fibers of the STT are organized such that SACRAL fibers are MOST LATERAL (thus LAST to be destroyed by a synrinx – sacral sparing of pain and temp)
Lesions: anterior spinal artery occlusion, syringomyelia/syrinx with sacral sparing, brown-sequard syndrome
Syringomelia/syrinx:
A spinal cord lesion at _____, which is an ___medullary lesion, primarily affecting ____ matter.
Usually involved ____ and ____ levels
Selectively interrupts the _____ fibers of the ____ tract –> deficits of ______ over those dermatomes but sparing of ______ –>
Signs/symptoms
Other tracts that could involve:
Spared tracts:
Causes:
Syringomelia/syrinx:
A spinal cord lesion at the cavity/syrinx/center of the spinal cord, which is an INTRAmedullary lesion, primarily affecting gray matter.
Usually involved cervical (“shaw” sx) and thoracic levels; pain and temperature mostly affected at the level of the lesion “vested”
Selectively interrupts the decussating fibers of the spinothalamic tract –> deficits of pain and temperature over those dermatomes but sparing of sacral dermaomes –>
Other tracts that could involve: if grows big enough, could invovle anterior horn, CST at ventral gray/lateral white matte
Spared tracts: DCT spared = vibration and position sense is intact
Causes: residual effects of SC injury, traumatic SC hemorrhage, intramedullary tumors, impaired CSF flow (congenital abnormality in the posterior fossa = chiari malformation)
Brown-sequard Syndrome:
= spinal cord _____
Causes:
What spinal tracts does it affect and what are the symptoms:
Brown-sequard syndrome = spinal cord hemisection
Tracts/sx:
STT - contralateral deficit to pa_in and temperature sensation_
DCT - ipsilateral deficit of vibration and position
Anterior horn cells / CST - ipsilateral weakness with LMN/UMN
Causes: trauma, extramedullary tumor, herniated disc with degeneration disease of bony spine
