Page 1
CH 11. 척수손상에
의한 통증 중재 - 1
Hwi-young Cho, PT, Ph.D
Gachon University. College of Healthscience. Depart of Physical Therapy.
(Pre) Korea University. College of Medicine. Depart of Physiology.
(Pre) Part-time instructor at Department of Physical therapy in Korea &
Sahmyook Univ. Graduate school
Page 2
Course schedule
• Anatomy & Physiology
• Neuroscience
• Pathophysiology
• Symptoms following SCI
• Target strategies for SCI
Page 3
Spinal Cord Injury (SCI)
• An SCI occurs when the spinal cord is damaged
as a result of trauma, disease, or congenital
defects
• Spinal cord = bridge from periphery to the Brain
• Nervous system
Page 4
http://www.surgicalneurologyint.com/article.asp?issn=2152-7806;year=2011;volume=2;issue=1;spage=156;epage=156;aulast=Ogungbo
http://www.meditouch.co.il/en/Spinal-Cord-Injury
Page 5
• Spinal cord 16 years after injury. Three spinal segments are telescoped into the space of one. The center of the scar is connective tissue which is invaded by regenerating fibers from the dorsal roots.
• Cervical spinal cord above a complete transverse traumatic lesion showing ascending degeneration in the dorsal (posterior) columns and spinal cerebellar and spinothalamic tracts.
Page 6
Left: Dorsal view of spinal cord
with fracture-dislocation at
the T12-L1 junction which
crushed the lumbar cord.
Top Right: Longitudinal
section showing site of direct
cord trauma and rostral and
caudal hemorrhagic
extension.
Bottom Right: Twelve
transverse sections through
the cervical and thoracic
cord. The third rows from
the left show almost
complete hemorrhagic
necrosis. Hemorrhages can
be seen in the grey matter in
other blocks for several
centimeters.
Page 7
Christopher Reeve
• 1995 (age 42), suffered from
a fall off a horse
• Was totally paralyzed
(tetraplegia) from a
complete C1/C2 injury
• Died October 2004 from a
pressure sore
http://www.IMDB.com
Page 8
Demographics (1)
• 82% male
• 50% between 15-24 y/o
• 80% < 40 y/o
Page 9
Demographics (2)
• Incidence (new cases/year)
• USA : 11,000
• Worldwide : 3,000,000
• Prevalence
• USA : 700,000
• Korea : 150,000
• Advanced medical technology
• Survival rate ↑
• SCI pt. = lifelong
Accumulate SCI pt
Page 10
Increased Life Expectancy with Spinal Cord
Injury due to Improved Patient Management
World War II: 3 months
1958: 3 years
1966: 20 years
1980: 21 years
Current: 27 +
Cause of Death: In the past-renal failure; Current-
cardiac failure, pneumonia, pulmonary emboli
and septicemia.
Therefore, we can turn our attention to therapeutic
opportunities to increase function after SCI.
Page 11
Falls
21%
Sports
8%
Other:
8%
Vehicular
Accidents
41%
Violence
22%
SPINAL CORD INJURIES
Source: National Spinal Cord Injury Statistical Center
Car Crashes: 83%
Motorcycle incidents: 10%
Bicycle accidents: 3%
Diving: 55% Snow skiing: 8%
Surfing: 6%
Gunshot: 92% Personal Contact: 6%
Page 12
SCI can occur from these causes..
• Trauma : automobile crashes, falls, gunshots, diving
accidents etc..
• Tumor : meningiomas, ependymomas, astrocytomas
• Ischemia : occlusion of spinal blood vessels, including
dissecting aortic aneurysms, emboli, arteriosclerosis
• Developmental disorders : spina bifida, meningomyolcoele
• Neurodegenerative diseases : Friedreich's ataxia,
spinocerebellar ataxia
• Demyelinative diseases : Multiple Sclerosis
• Vascular malformations : arteriovenous malformation
(AVM), dural arteriovenous fistula (AVF), spinal
hemangioma, cavernous angioma and aneurysm
Page 13
Quality of Life Issues Targeted by Patients
of Spinal Cord Injury
1. Bowel and bladder control
2. Pain management
3. Hand use if limited
4. Improved locomotor function
Restorative treatments will be incremental; thus, both basic
and clinical measures need to be refined to be able to
detect the interventions that are successful.
Page 14
Live & Lifelong Needs of SCI
• Medical doctor
• Physical therapist
• Occupational therapist
• Psychosocial
• Financial
• Vocational
• Social Functioning
Page 15
The recent trend of Rehab
• Physical therapy
• Occupational therapy
• Human engineering (=Ergonomics)
• National institute
• Private research company
Page 16
Virtual Reality
http://master.design.zhdk.ch/projekte/a-physiotherapeutic-
video-game-for-children
Page 17
Assistive Robotic Manipulator (Netherland)
WAM Arm (USA, Barrett Tech Inc.)
Page 18
The Latest Trends for SCI Tx
• Cell Therapy approach
Stem cells
Embryonic stem cell
Fetal stem cell
Neural stem cell
Induced pluripotent cell
Et al..
USA 캘리포니아주의 CIRM (3조원)
역분화 줄기세포연구: Harvard, MIT
배아줄기세포 임상연구: UC Irvine, Geron Inc
EU 8개국 11개 연구기관 공동참여
영국 UK Stem Cell Initiative (약 2조원)
Japan Milenium Project로 세포치료 선정 (200억원)
고베시 재생의료 클러스터 조성
Kyoto Univ. 역분화 연구 지원 (연간 550억원)
Pharmaceutical
Industry
Pifzer: 스웨덴 연구팀과 공동연구 협약
Roche: 미국 DCI사와 줄기세포 약물스크리닝 개발
AstraZeneca, GSK, Roche: SC4SM 컨소시엄 구축
GSK: 하버드 줄기세포 연구소에 5년간 최소 2500
만 달러 투자
생명공학 정책 연구센터 BT 기술동향 보고서, 2008
Page 19
NYU
impactor
Animal
preparation
Cord
exposure
Impact
loading
Page 20
Intracerebral
Intravenous (tail vein) Intra-arterial Intra-thecal
(A) (B) (C) (D)
Caudal Rostral
(E)
Page 21
F3.BDNF
characteristics
Neural Mature
Marker
Neural
Immature
Marker
: Mature
potency
Immortalization
Page 23
Inflammation Gliosis Apoptosis Endogenous neurogenesis
NSC
Page 24
My Suggestion!
• Additional PT & OT intervention with Stem
cell therapy.
Physical rehab may boost the recovery of physical
functions following stem cell therapy.
• Limitation
• Required the suitable Subjects involving Stem cell
therapy.
Page 25
Anatomy & Physiology
Spinal architecture
&
Spinal cord
Page 26
http://www.17daydiets.com/search/spinal-nerves
Page 27
http://www.merckmanuals.com/home/brain_spinal_cord_and_nerve_disorders/biology_of_the_nervous_system/spinal_cord.html
Page 28
http://www.merckmanuals.com/home/brain_spinal_cord_and_nerve_disorders/spinal_cord_disorders/overview_of_spinal_cord_disorders.html
Page 29
In vertebrates
1st defense
• The Brain = bony skull (Cranium)
• The spinal cord = vertebral column
2nd defense
• Meninges
1. The Dura matter
• Thick
• Veins
2. The Arachnoid membrane
• Loosely tied to the Pia
3. The Pia matter
• Adheres to CNS
• Arteries
3rd defense
• Extracellular fluids : cushion
Final : BBB
http://apbrwww5.apsu.edu/thompsonj/Anatomy%20&%20Physiology/2010/2010%20Exam%20Reviews/Exam%204%2
0Review/CH%2012%20Gross%20Anatomy%20of%20the%20Spinal%20Cord.htm
Page 30
2nd defense
1st defense
Page 31
3 Meningeal layers
2nd defense
http://www.pennmedicine.org/encyclopedia/em_DisplayImage.aspx?gcid=19088&ptid=2
Page 32
http://apbrwww5.apsu.edu/thompsonj/Anatomy%20&%20Physiology/2010/2010%20Exam%20Reviews/Exam%204%20Review/CH%2012%20Gross%20Anatomy%20of%20the%20Spinal%20Cord.htm
Page 33
http://apbrwww5.apsu.edu/thompsonj/Anatomy%20&%20Physiology/2010/2010%20Exam%20Reviews/Exam%2
04%20Review/CH%2012%20Gross%20Anatomy%20of%20the%20Spinal%20Cord.htm
Page 34
3rd defense
• Extracellular fluids
• Cranium = 1.4 L (fluid = ICF + ECF)
• The cell = 1L
• Extracellular fluids
• The blood = 100 – 150 ml
• The cerebrospinal fluids & interstitial fluids = 250 – 300 ml
• Form the extracellular environment for neurons.
Page 35
Extracellular fluids in CNS
• The cerebrospinal fluids & interstitial fluids
1. The cerebrospinal fluids (CSF)
• In the ventricles & between the pia & arachnoid space
• A salty solution that is continuously secreted by the chroid
plexus(vnetricle).
2. Interstitial fluids
• Inside the pia mater
Page 36
The cerebrospinal fluids (CSF)
• Flow sequence
• Ventricle → subarachnoid space → flows around
the neural tissues → absorbed back into the blood
by villi on arachnoid membrane
• Purpose
1. Physical protection
2. Chemical protection
Page 37
1. Physical protection
• Buoyancy
• ↓ the weight of brain nearly 30 fold
• Less pressure on blood vessels & nerves
• Protective padding
• Tofu in an empty jar VS Tofu in a jar completely
filled with water
Page 38
Cerebral Ventricles
http://www.lookfordiagnosis.com/mesh_info.php?term=Cerebral+Ventricles&lang=1
Page 39
http://apbrwww5.apsu.edu/thompsonj/Anatomy%20&%20Physiology/2010/2010%20Exam%20Reviews/Exam%204%20Revie
w/CH%2012%20Cerebrospinal%20Fluid.htm
Page 40
Cerebrospinal
circulation
http://www.mananatomy.com/body-systems/nervous-system/ventricular-system-brain
Page 41
2. Chemical protection
• Closely regulation
• Choroid plexus
• Composition
• K, Ca, HCO, glucose level : ↓
• H : ↑
• Na : similar to the blood
• Very little protein & no blood cells
Page 42
Choroid plexus (맥락막총)
http://searchpp.com/choroid-
plexus/classconnection.s3.amazonaws.com*183*flashcards*799622*png*choroid-
plexus.png/imgarcade.com*1*choroidplexus/
http://www.corpshumain.ca/en/Cerveau3_en.php
Page 43
Final defense : BBB
• Blood brain barrier
• Between the interstitial fluid & the blood
• Protection from pathogens such as bacteria
• Brain capillary
• Selective permeability : hormones, ions and NTs
• Tight junction
Page 44
Cerebrospinal fluid Clear
50-200 mm H2O pressure
0-10 WBC 0 RBC
< 45 mg/100 ml protein glucose 2/3 blood level 50-80 mg/100 ml
Dural sac ends at vert. S1-S2
Spinal tap done at L3-L4
http://slvshade.tistory.com/168
Page 45
http://slvshade.tistory.com/168
Page 46
Blood supply
• Paired spinal arteries
• branch off the vertebral, cervical, thoracic, and lumbar arteries
• Travel through the intervertebral foramina, split into anterior and posterior arteries
http://www.frca.co.uk/article.aspx?articleid=100360
Page 47
http://www.frca.co.uk/article.aspx
?articleid=100360
Page 48
Anatomy Review
• Cervical Spine
• 7 vertebrae
• very flexible
• C1: also known as the atlas
• C2: also known as the axis
• Thoracic Spine
• 12 vertebrae
• ribs connected to spine
• provides rigid framework of thorax
Page 49
Anatomy Review
• Lumbar Spine
• 5 vertebrae
• largest vertebral bodies
• carries most of the body’s weight
• Sacrum
• 5 fused vertebrae
• common to spine and pelvis
• Coccyx
• 4 fused vertebrae
• “tailbone”
Page 50
Anatomy Review
Vertebral body •posterior portion forms part of
vertebral foramen
•increases in size from cervical to
sacral
•spinous process
•transverse process
Vertebral foramen •opening for spinal cord
Intervertebral disk •shock absorber (fibrocartilage) http://biology.stackexchange.com/questions/20427/difference-between-
intervertebral-and-vertebral-foramina
Page 51
http://en.wikipedia.org/wiki/Nervous_system#mediaviewer/File:NSdiagram.svg
Page 52
Autonomic Nerve System
http://wiki.bethanycrane.com/somaticautonomicnervoussystems
Page 53
http://howmed.net/wp-content/uploads/2010/09/functions-of-autonomic-nervous-system.bmp
Page 54
http://howmed.net/wp-content/uploads/2010/09/functions-of-ans-cont..bmp
Page 56
Origin from CNS & location of autonomic
ganglia
Sympathetic
• Origin : thoracic &
lumbar
• Ganglia : close to spinal
cord
• Pre : short
• Post : long
Parasympathetic
• Origin : brain stem,
cervical & sacral region
• Ganglia : near target
organ
• Pre : long
• Post : short
• 75% : vagus n. (Ⅹ)
• Stability
Page 57
Vagus nerve
http://www.netterimages.com/image/4620.htm
Page 58
Redistribution of Blood Flow During Exercise
Changes in Oxygen Delivery to Muscle During Exercise
1.25 ℓ
1.25 ℓ 1 ℓ 1 ℓ
1.25 ℓ 0.25 ℓ 1 ℓ 0.75 ℓ
Page 59
Spinal Cord & Spinal Nerves
• Spinal nerves begin as
roots
1. Dorsal or posterior root is
incoming sensory fibers
• dorsal root ganglion =
cell bodies of sensory
nerves
2. Ventral or anterior root is
outgoing motor fibers
Posterior
Root
(Sensory)
Anterior
Root
(Motor)
Page 60
Direction of
Information flow in neurons
• Sensory/Afferent neurons
; conduct impulses into
CNS
• Motor/Efferent neurons
; carry impulses out of CNS
• Association/ Interneurons
; integrate NS activity
• Located entirely inside
CNS http://en.wikipedia.org/wiki/Afferent_nerve_fiber#mediaviewer/File:A
fferent_(PSF).png
Page 61
Neuroscience
Neuron
Spinal cord
Page 62
Copyright © 2005 Pearson
Education, Inc., publishing as
Benjamin Cummings.
Organization of the Nervous System
Page 63
Structures of a neuron
1) Cell body ( = perikaryon or soma)
2) Dendrites (the receiving end) :
3) Axon (the outgoing end) :
* Axon hillock
4) Presynaptic terminals
http://www.enchantedlearning.com/subjects/anatomy/brain/Neuron.shtml
Page 64
Neurons and Synapses
Types of Neurons
Sensory Motor Interneurons
Page 65
Neuron
- Electrically excitable
- Receive information
- Generation & propagation of action potential
- Neurotransmitter release : communicate with other neuron
http://www.wpclipart.com/medical/anatomy/cells/neuron/neuron.png.html
Page 66
How neurons communicate
• Neurons communicate by means of an electrical signal
called the Action Potential
• Action Potentials are based on movements of ions be-
tween the outside and inside of the cell
• When an Action Potential occurs, a molecular message is
sent to neighboring neurons
Page 67
Action potentials Synaptic potentials
Voltage Gated Na+ CH
http://www.slideshare.net/schwartzcm/ch-8-neurons-9-11
Page 68
http://www.slideshare.net/schwartzcm/ch-8-neurons-9-11
Page 69
3 : Threshold -45 mV = voltage-
gated Na+ CH open
5 : voltage-gated
Na+ CH
inactivated gate
close & voltage K+
CH open http://www.slideshare.net/schwartzcm/ch-8-neurons-9-11
Page 70
http://www.slideshare.net/schwartzcm/ch-8-neurons-9-11
Page 71
http://www.slideshare.net/schwartzcm/ch-8-neurons-9-11
Page 72
http://www.slideshare.net/schwartzcm/ch-8-neurons-9-11
Page 73
http://www.slideshare.net/schwartzcm/ch-8-neurons-9-11
Page 74
Synapse
• Synapse (place)
• Neural communication
• Electrical current & chemical transfer (method)
• Dz & disorder in order to synaptic
communication
• Disrupt neural function (nerve-muscle signaling)
Page 75
Structure of the synapse
1. Presynaptic terminal
The end of the axon
A projection specialized for the release of chemicals
Contain vehicle : neurotransmitters(NT)
NT : transmit information
2. Postsynaptic terminal
The membrane region of the receiving cell
3. Synaptic cleft
The space between the two terminals
Page 76
Synapse
• Two basic forms;
• Electrical synapse; rapid and stereotyped
• Chemical synapse;
http://pixshark.com/che
mical-synapses.htm
Page 77
Electrical synapse
http://en.wikipedia.org/wiki/Electrical_synapse#mediaviewer/File:Gap_cell_junction-en.svg
Page 78
Chemical synapse
http://pixshark.com/chemical-synapses.htm
Page 79
Neurotransmitters produce diverse postsynaptic
responses
• Transmitters (information transport)
• 3 styles of receptor-channel coupling
• Ionotropic
• Metabotropic
• Activating a cascade of intracellular events
• Amino acid neurotransmitters produce fast PSPs
• Amine and peptides are slower neuromodulators
Page 80
Glutamate-gated channel; excitatory
http://webvision.med.utah.edu/imageswv/GLU5.jpeg
Page 81
GABA- and glycine-gated channels;
inhibitory
• GABAA; ionotopic, Cl-
• GABAB; metabotropic, K+
• Glycine; ionotropic, Cl-
http://sites.sinauer.com/psychopharm2e/webbox18.04.html
Page 82
Neurotransmission
• Fast excitatory transmission
Na channel open in postsynaptic neuron
• Fast inhibitory transmission
Cl channel open in postsynaptic neuron
• Slow inhibitory transmission
K channel open in postsynaptic neuron
• Slow excitatory transmission
K channel block in postsynaptic neuron
Page 83
Locks and Keys
• Neurotransmitter molecules
have specific shapes
• positive ions (NA+ ) depolarize
the neuron
• Negative ions (CL-)
hyperpolarize
When NT binds to receptor,
ions enter
• Receptor molecules have
binding sites
http://pharmacymagazine.blogspot.kr/
Page 84
Some Drugs work on receptors
• Some drugs are shaped
like neurotransmitters
• Antagonists : fit the
receptor but poorly and
block the NT
• Agonists : fit
receptor well and
act like the NT
• e.g. nicotine.
http://pharmacymagazine.blogspot.kr/
Page 85
https://courses.washington.edu/psy222/psy222drugsaddiction.html
Page 86
Methylprednisolone - trials
1. No neurological difference one year post injury
Insufficient dose
2. Small but significant improvements in motor scores at one year
Lack of standardised assessment of functional outcome, rather than basic motor scores
3. Greatest benefit within the first 3hours
• Remains only an option in SCI
• complications
• increased incidence of infection
• Gastrointestinal problems
• Pulmonary issues
• Long-term effects
• Mixed evidence
Page 87
Alternatives
• Naloxone • opiate antagonist
• No clinical benefit
• Tirilazad • 21-aminosteriod
• No benefit
• No true placebo group
• GM-1 • Ganglioside
• Two randomised trials
• Improvement in smaller trial not detected in larger one
• Remains an option
• Other agents with no benefit • Thyrotropin-releasing hormone
• Gacyclidine (NMDA-receptor antagonist)
• Nimodipine (calcium channel antagonist)
• 4AP • K+ channel antagonist
• Stabilises axonal membranes during acute injury only
• Riluzole • Sodium channel antagonist
• Improved outcome in animal models
• Approved for treatment of amyotrophic lateral sclerosis
• Attenuation of inflammatory response • COX-2, NSAIDS, tetracycline,
erythropoeitin
• Improved functional recovery
Page 88
Integration of neural information transfer
http://www.slideshare.net/schwartzcm/ch-8-neurons-9-11
Page 89
Spatial summation
http://www.slideshare.net/schwartzcm/ch-8-neurons-9-11
Page 90
Temporal
summation
http://www.slideshare.net/schwartzcm/ch-8-neurons-9-11
Page 91
http://www.slideshare.net/schwartzcm/ch-8-neurons-9-11
Page 92
Glia (Neuroglia); Supporting cells
• Within the CNS ; astrocytes, ependymal cells and microglia
• In the PNS ; Schwann cells
http://www.slideshare.net/schwartzcm/ch-8-neurons-9-11
Page 93
Glial cell
• Function
• Support network for neurons
• Transmit information (Parpura, 2000)
• Ailments : Alzheimer`s Dz, Multiple sclerosis
• Categorize
• Macroglial cells
• Astocytes
• Oligodendrocytes
• Schwann cells
• Microglia cells
Page 94
http://www.slideshare.net/schwartzcm/ch-8-neurons-9-11
Page 96
Spinal tracts
https://www.boundless.com/physiology/textbooks/boundless-anatomy-and-physiology-textbook/peripheral-nervous-system-pns-13/distribution-of-spinal-nerves-133/sensory-and-motor-tracts-720-6504/
Page 97
Tracts of the Spinal Cord
• Function of tracts
1. Highway for sensory & motor information
2. Sensory tracts ascend
3. Motor tracts descend
• Naming of tracts
• Indicates position & direction of signal
• Example = anterior spinothalamic tract
• Impulses travel from spinal cord towards brain (thalamus)
• Found in anterior part of spinal cord
Page 98
Location of Tracts inside Cord
Motor tracts Sensory tracts
pyramidal tract (corticospinal) spinothalamic tract
extrapyramidal tract posterior column
spinocerebellar
Page 99
Function of Spinal Tracts
two-point discrimination,
pressure and vibration
pain, temperature,
deep pressure
https://www.boundless.com/physiology/textbooks/boundless-anatomy-and-physiology-textbook/peripheral-nervous-system-pns-13/distribution-of-spinal-nerves-133/sensory-and-motor-tracts-720-6504/
Page 100
Function of Spinal Tracts
voluntary movements,
posture & muscle
tone, equilibrium
https://www.boundless.com/physiology/textbooks/boundless-anatomy-and-physiology-textbook/peripheral-nervous-system-pns-13/distribution-of-spinal-nerves-133/sensory-and-motor-tracts-720-6504/
Page 101
1. Ascending Tracts
• Carry sensory signals up to the supraspinal region
• Typically uses 3 neurons
• 1st order neuron - detects stimulus and carries it to spinal
cord
• 2nd order neuron - within s.c.; continues to the thalamus
(the sensory relay station)
• 3rd order neuron - carries signal from thalamus to
sensory region of cerebral cortex
Page 102
• Carries sensations related to
discriminative touch, vibration,
and proprioception
• 1st order neuron - detects stimulus
• Fasciculus gracilis
• Carries sensation from below T6
• Fasciculus cuneatus
• Carries sensation from T6 or higher
• 2nd order neuron synapses with 1st in
medulla and decussates
• 3rd order neuron synapses with 2nd in
thalamus and carries signal to cerebral
cortex (postcentral gyrus)
• System is contralateral
1-1. Dorsal Column Ascending Pathway
http://www.corpshumain.ca/en/Touche_en.php
Page 103
1-2. Spinothalamic Pathway
• Carries sensations of pain, pressure, temperature, light touch, tickle and itch
• Located in the anterior and lateral columns
• Decussation of the second order neuron occurs in spinal cord
• Third order neurons arise in thalamus and continue to cerebral cortex of the postcentral gyrus
http://www.corpshumain.ca/en/Touche_en.php
Page 104
1-3. Spinocerebellar Pathway
• 1st order neurons originate in muscles and tendons
• 2nd order neurons ascend in ipsilateral lateral column
• Terminate in cerebellum (a large motor control are of the brain)
• Transmit proprioceptive signals from limbs and trunk
Page 105
2. Descending (Motor) Pathways
• Brain → spinal cord
• Pyramidal tracts (Direct pathways)
• Corticospinal tract
• Corticobulbar tract
• Extrapyramidal tracts (Indirect pathways)
• Vestibulospinal tract
• Tectospinal tract
• Reticulospinal tract
• Rubrospinal tract
• Motor pathways involve two neurons
• Upper motor neuron (UMN)
• Lower motor neuron (LMN)
Page 106
2-1. Pyramidal Tracts
• Originate from the pyramidal cells of the primary motor
cortex. These nerve tracts decussate.
2-1-1. Corticobulbar tract • Originate : primary motor cortex of the cerebrum.
• Destination : motor nuclei of cranial nerves in the brain stem.
• Provide conscious control over skeletal muscles of the eye, jaw
and face, as well as some muscles of the neck and throat.
2-1.2. Corticospinal tracts • Origination : primary motor cortex of the cerebrum.
• Destination : the ventral horns of gray matter in the spinal cord.
• Provide voluntary motor control of skeletal muscles throughout
the body.
Page 107
2-1. The
Direct
(Pyramidal)
System
http://www.profelis.org/webpages-
cn/lectures/neuroanatomy_3.html
Page 108
2-2. Extra-Pyramidal tracts
Originate from centers in the cerebrum, diencephalon and
brain stem not from pyramidal cells (extra-pyramidal).
2-2-1. Vestibulospinal tracts – do not decussate • Neurons respond to information from the vestibulocochlear nerve
about the position and movements of the head.
• The tract carries motor commands that alter muscle tone and position
the head, neck and limbs to maintain balance and posture.
2-2-2. Reticulospinal tract (reticular formation)
• Controls limb movements important to maintain posture and balance
Page 109
2-2. Extra-Pyramidal tracts
Originate from centers in the cerebrum, diencephalon and
brain stem not from pyramidal cells (extra-pyramidal).
2-2-3. Tectospinal tracts – Cross over in the brain stem • Neurons originate in the superior and inferior colliculi in the tectum of
the midbrain. The colliculi receive visual (superior) and auditory
(inferior) sensations.
• Neurons of these tracts direct reflexive changes in the position of the
head, neck and upper limbs in response to bright lights, sudden
movements or loud noises.
2-2-4. Rubrospinal tracts • Originate in ‘red nucleus’ of midbrain; control flexor
Page 110
2-2. Indirect
(Extrapyramidal)
System
http://www.profelis.org/webpages-cn/lectures/neuroanatomy_3.html
Page 111
Example Motor and Sensory Pathways
To thalamus and cerebral cortex (sensory)
Brain
Stem
Spinal
Cord
Pain - Temp Proprioception
(conscious)
Spinothalmic
tract
Example Motor Pathway
(corticospinal tract)
LMN
Motor Cortex
Corticospinal
tract
Posterior
column