Module 7 Flashcards
- continuous with meninges of brain, protect spine, carry blood supply
- surrounds the spinal cord
Meninges
- tough fibrous tissue; epidural space: contain loose connective tissue and adipose, anesthetic injection site
Dura mater
- simple squamous epithelium; subarachnoid space is filled with CSF and contains trabeculae (collagen/elastin fiber network)
Arachnoid
- bound to spinal cord; made of collagen and elastic fibers
Pia mater
- extend from pia to dura matter and stabilize side to side movements
- gives stability of the cord
Denticulate ligaments
- protected by the vertebral body. The format in the axial cut is an H-shaped gray matter surrounded by the white matter. The gray matter has a dorsal and ventral horn.
- is symmetric. Cervical and Lumbar enlargement caused by amt of motor neurons in gray matter
- extends from the cervicomedullary junction down to the level of L1 and L2
Spinal cord
Thoracic, Lumbar, Sacral may have a __.
lateral horn
Sympathetic vs Parasympathetic
At the level of your thoracic T1 to L2 that will be your sympathetic outflow.
S1-S4 parasympathetic outflow.
Potential Spaces in the Spinal Cord
- Epidural Space - filled with fat
- Subdural Space
- Subarachnoid Space - contains CSF
Blood Supply of the Spinal Cord
- two posterior spinal arteries to support the posterior part
- one anterior spinal artery
Posterior and Anterior root
Posterior root - going into the dorsal Horn
Anterior root - going out of the ventral horn
*this two will unite to form the spinal root (carries sensory and motor fiber)
Cervical and Lumbar Part
- Cervical and Lumbar part are fatter because they serve the limbs; means more nerve bodies
- part of the pia mater; goes down and attaches itself to the coccyx
Filum Terminale
- space that is created where there is no more cord is occupied by __
Cauda Equina
- this cord will go out above the vertebral body
C1-C7
- cords that will exit below the vertebral body
C8 going down
- usually have a discrepancy of about 2 segments
- eg T4 vertebra will correspond to T6 spinal cord segment
Upper half of the thoracic
- spinal segments usually have a discrepancy of about 3 segments
- eg T11 vertebral body will correspond to L1 spinal cord segment
Lower half of the thoracic and Lumbar
- limited only for the sensory which is the dorsal column
Posterior
9 cell layers or laminae:
1-6 dorsal,
7 intermediate,
8-9 ventral
- separate dorsal gray column from surface of spinal cord
Zone of Lissauer
- axons contribute to lateral spinothalamic; pain temp
Nucleus posterior marginalis
- pain, temp, light touch; contribute axons to lateral and ventral spinothalamic; have Mu and Kappa opioid receptors;
Substantia gelatinosa (II)
- fine touch and proprioception; pain and temp; contribute to lateral spinothalamic, ventral spinocerebellar
Nucleus proprius (III,IV,V)
- supplies posterior or dorsal spinocerebellar tract; fine touch and proprioception
Nucleus dorsalis
- Transmit impulses concerned with specific sensory modalities
- Transmit impulses from stretch receptors and tactile receptors that project directly or via relay nuclei to the cerebellum
- Impulses projected to the cerebellum play an important role in the regulation of muscle tone and coordination of motor function
ASENDING TRACTS
Posterior column: Fasciculus Gracilis and Cuneatus → Spinal Cord synapse in Nucleus Gracilis/Cuneatus (at the level of the medulla) → cross in lower medulla → (Ventral Posterolateral) Thalamus → Postcentral gyrus
- Discriminating tactile and kinesthetic sense
Dorsal Column Medial Lemniscal Pathway
Nucleus Gracilis vs Nucleus Cuneatus
Gracilis - Gitna; supplies the lower half of the body
Cuneatus - lateral; supplies the upper half of the body
Finely/unmyelinated lateral bundle of dorsal root → bifurcate after entering zone of Lissauer: ascending and descending branches (it descends/ascends by 1 or 2 spinal segments)→ terminate on interneurons of dorsal horn in laminae 6,7→ decussate via ventral commissure→ ventral posterolateral nucleus of thalamus→ parietal lobe (pain and temp)
*Laminar: sacral – ventrolateral, cervical – dorsomedial; temp – dorsolateral to pain
Lateral Spinothalamic Tract
Lateral Spinothalamic Tract
- Laminae I, IV and V
- Spinal Cord→Cross in the anterior white commissure→ thalamus→ Postcentral gyrus
- Pain and thermal sense
- Laminae I, IV, and V
- Spinal Cord → Cross in the anterior white commissure→ thalamus→ Postcentral gyrus
- Conveys impulses associated with light touch
Anterior Spinothalamic Tract
- Laminae I and V of posterior horn
- Spinovisual reflex: posterior root (Spinal Cord)→Cross in the anterior white commissure→ superior colliculus and lateral regions of the periaqueductal gray
Spinotectal Tract
- Dorsal nucleus of clarke, uncrossed
- Spinal Cord → inferior cerebellar peduncle → rostral and caudal vermis
- Carries proprioceptive information from the LOWER LIMBS TO THE IPSILATERAL CEREBELLUM.
Posterior Spinocerebellar Tract
- Follow the posterior spinocerebellar tract
- Terminate on the cells of the accessory cuneate nucleus →inferior cerebellar peduncle→ lobule V of cerebellar cortex
- Carries proprioceptive information from the UPPER LIMBS TO THE IPSILATERAL CEREBELLUM.
- Continuation of posterior spinocerebellar tract
Cuneocerebellar Tract
- Laminae V, VI and VIII, crossed
- Spinal Cord→superior cerebellar peduncle→ anterior cerebellar vermis
- Carries proprioceptive information from the lower limbs.
- The fibres decussate twice – and so terminate in the ipsilateral cerebellum
Anterior Spinocerebellar Tract
- Another component of the spinocerebellar circuitry where impulses from spinal cord are relayed to the cerebellum via parts of the inferior olive
- Posterior columns→ nucleus cuneatus/gracilis→ accessory olivary nuclei
Spino-olivary Tract
- Cells of the posterior horn
- Spinal cord → reticular formation in the brainstem
- Behavioral awareness, modification of motor and sensory activities and in the modulation of electrocortical activity
Spinoreticular Fibers
- Ill-defined pathway coursing through ventrolateral pathway of cord, synapsing on the reticular formation of the brainstem without crosssing → eventually it will terminate on the intralaminar nucleus of the thalamus (poorly localized pain sensation)
Spinoreticular Fibers
COMMON SENSES
- Touch
- Pain
- Temperature
- Position
- Vibration
- Stereognosis-form (stereoanesthesia- checking for the integrity of nerves)
- higher cortical function; knowing what the object is from its size, shape and texture
Stereognosis
- intact nerve fiber but when you ask the pt to close their eyes they don’t know the object is by its form
Stereoagnosia
- increased sensitivity to touch, pain, and temperature
Hyperesthesia, hyperalgesia and hyperthermesthesia
- extreme over-response to pain; increase threshold for pain but once they detect the pain they will have exaggerated reaction; Late nadedetect ung pain pero exaggerated na ang pagreact
Hyperpathia
- abnormal perception of pain from a nonpainful stimulus, with delayed perception and aftersensation. Common in trigeminal neuralgia
- they are the patient that even when they talk or chew, they will experience pain
- nonpainful stimulus being detected as pain
Allodynia
- multiple, very severe, electric shock-like pains. Common in Sciatica
Neuralgia
- uncomfortable sensations (spontaneous sensations) of numbness, tingling, pins and needles or burning pain
Paresthesias and dysesthesias
- unbearable, burning, relentless pain. Pt who have taken drugs, cancer (they have adverse drug reaction eg chemotherapy drug)
Causalgia
- any abnormal sensation described as unpleasant (more intense than paresthesia);
Dysesthesia
Muscle spindle contain intrafusal fibers: the nuclear chain fiber that give information on muscle length and nuclear bag fibers that give information on the rate of change in muscle length. You therefore have two types of receptor:
- flower spray endings for muscle length
- annulospiral endings for muscle ength and velocity.
These receptors (muscle spindle) belong to neurons that eventually synapse on your alpha motor neurons, completing the arch for your __.
myotatic reflex
The __ is located on muscle tendons, the Ib afferent fiber eventually synapse on inhibitory interneurons, mediating your inverse stretch reflex which helps prevents injury to the tendon from too much tension. It supposed to relax rhe muscle.
Golgi tendon organ
Joint: Pacinian
Joint movement
Joint: Rufini
Joint angle
Joint: Golgi Tendon Organ
Joint torque
- Touch, flitter or movement
Meissner corpuscle
- Vibration, ticke
Pacinian corpuscle
-Skin stretch, warmth
Ruffini corpuscle
- detecting touch movement
Hair follicle
- Pressure
Merkel complex
- Sharp pain or cool/cold (Axon Group III)
- Dull or aching pain, or touch or warm (Axon Group IV)
Free Nerve endings
GENERAL PRINCIPLES IN TESTING SOMATIC SENSATIONS:
- Demonstrate and describe the tests
- Have patient close the eyes to avoid visual cues
- Compare: Right vs. Left; Normal vs. Abnormal
- Skin areas differ greatly in sensitivity
- Plan follow-up examination to recheck any doubtful results
- Determine whether sensory deficits match a central pathway, dermatomal, plexus or peripheral nerve pattern or a nonorganic distribution
- Recognize that the Pt’s mental state, legal wrangling or secondary gain from the illness may drastically alter sensory test results
TRIGEMINOTHALAMIC PATHWAY (Nucleus)
- Spinal tract and Nucleus of V: pain and temperature sensation at the level of the medulla
- Chief sensory nucleus of V: vibration, proprioception and light touch/tactile discrimination
- Mesencephalic nucleus of V: (at the midbrain) unconscious proprioception of muscle
CRANIAL V SENSORY EXAMINATION
- INSTRUCTION: Ask the Pt to say touch in response to each touch by a wisp of cotton
- Touch alternate areas and sides of the face randomly
- If the history indicates a specific area of sensory loss, start sensory testing in normal area, then start in the middle of the abnormal area and work outward
ANATOMY
- Afferent: CN V
- Efferent: CNVII
TECHNIQUE
- Use free piece of cotton rolled to a fine point
Instruct the Pt to look to one side and a little up
- Bring the cotton directly in from the side to avoid entering the field of vision
THE CORNEAL REFLEX
Problem on the CN V on the Right, When you do a corneal reflex, where is the slow blink?
BOTH because the problem is the afferent arm
Problem on the CN VII on the Right (partial bell’s palsy), corneal reflex on the right, where is the slow blink?
Right because the problem is the efferent arm
Problem on the CN VII on the Right (partial bell’s palsy), corneal reflex on the left, where is the slow blink?
Right because you have a normal CN V on the left but you have a problem in CN VII on the right (so whenever you blink and check the corneal reflex, the blink on the right will be slow)
- Largest number of spinothalamic fibers arise from cells in laminae I, IV, and V contralaterally
- Conveys impulses associated with “light touch”
- Receptors: Meissner’s corpuscle (tactile
ANTERIOR SPINOTHALAMIC TRACT
TESTING LIGHT TOUCH SENSATION
- For screening purposes, test only the dorsum of the hands and feet in addition to the face
- Transmits impulses for pain and thermal sense
- Cells of origin largely in laminae I, IV and V
- Cross to the opposite side
- Fibers related to thermal sense tend to be posterior to those related to pain
- Receptors: free nerve endings (pain), cold and heat receptors of dermatome
LATERAL SPINOTHALAMIC TRACT
TEMPERATURE AND PAIN DISCRIMINATION
- INSTRUCTION: Ask the Pt to close their eyes
- TUNING FORK or LITTLE FINGER TEST
- PAIN: Avoid the horny skin of the palms and soles; Delayed and Deep Pain
Testing for Delayed and Deep Pain Sensation
- Testing delayed pain: pinching the dorsum of the patient’s foot briskly between the fingernails of your thumb and index finger. Normally, the person will feel the immediately.
- Deep pain can be tested by squeezing hard on the Achilles tendon or a muscle. You can also press very hard on a bony surface. The patient may feel pain some seconds after ending the compression.
- usually result in contralateral pain and temperature sensation
- usually caused by Multiple Sclerosis, Trauma, Tumors of the cord
SPINOTHALAMIC TRACT LESIONS
- Discriminating tactile sense (touch and pressure) and kinesthetic sense (position and movement)
- Receptors: pacinian corpuscle, unencapsulated joint receptor, Golgi and Meissner’s corpuscle
DORSAL COLUMN PATHWAY
VIBRATION AND POSITION SENSE (TEST)
POSITION SENSE
- Use the 4th Digit (least cortical representation)
- Do five trials
- Romberg Test
VIBRATION
- Instructions
- Apply to the Pt’s fingernails and toenails or just proximal to nailbed
- PALLANESTHESIA
*Minimum of five trials so that the patient has only a 50% chance of getting it right by merely guessing.
Aging increases the threshold to vibration and reduces the sensitivity. Normally, the hands feel vibration better than the feet at all ages.
ALTERNATIVE TESTS
DIRECTIONAL SCRATCH TEST
- 10 Trials
- 2cm, 5cm, 10 cm
TWO-POINT DISCRIMINATION
- 2-4mm on fingertips, 4-6mm on dorsum of fingers, 8-12mm on palm and 20-30mm on dorsum of the hand
STEREOGNOSIS
– inability to recognize shape and form (problem with proprioceptive and tactile sensation)
Stereoanesthesia
– inability to identify the object or distinguish objects by their size, shape weight and tecture using palpation even with intact sensation; results from lesion of the opposite parietal lobe. (left injured when right, both injured when left)»_space; cannot separate cone from pyramid
Astereognosis
– lesion in dominant parietal lobe results in inability to identify object in both hands – disorder of apperception of stimuli and translating them into symbols.
Tactile agnosia
- result in ipsilateral loss of the proprioception
DORSAL COLUMN LESIONS
- result in ipsilateral loss of light touch, vibration, and position sense on the upper half of the thoracic
FASCICULUS CUNEATUS LESION
- proprioception loss below the level of the lesion
BILATERAL DORSAL COLUMN LESION
Area of the skin supplied by a single nerve
Dermatomes
(Dermatomes)
C2
hood distribution
(Dermatomes)
C3 and C4
cape distribution
(Dermatomes)
C5-T1
UE
(Dermatomes)
T4
Nipple
(Dermatomes)
T10
Umbilicus
(Dermatomes)
Groin
L1
(Dermatomes)
L5
large toe
(Dermatomes)
S1
small toe
- Anesthesia or hypesthesia
- Analgesia or hypalgesia
- Thermanesthesia or thermhypesthesia
- Loss of dorsal column modalities
DEFICIT PHENOMENA
- Hyperesthesias: paresthesias and dysesthesias
- Hyperalgesia, hyperthemesthesia, hyperpathia, neuralgia, causalgia
IRRITATIVE PHENOMENA
- Irritation of trigeminal nerve, usually idiopathic but may be related to MS, aneurysm, arterial compression, tumor, dental problem
- Lancinating pain within trigeminal distribution
- Commonly unilateral
TRIGEMINAL NEURALGIA
- Absence of reflexes, LMN paresis, atrophy and fasciculations at level of lesion
- Early period of spinal shock
- Complete loss of motor and sensory function below the level of the lesion
- Trauma, tumor, hematoma, abscess, infectious or inflammatory transverse myelitis
COMPLETE SPINAL CORD TRANSECTION
- lesion sparing of the dorsal column
- usually vascular problems (aortic diseases), trauma, abcess
Anterior Cord Syndrome
- Contralateral loss of pain and temperature below the lesion
- Ipsilateral loss of pain and temperature at level of lesion
- Ipsilateral loss of vibration and proprioceptive sensation below lesion
- Ipsilateral pyramidal weakness
- Ipsilateral LMN paresis at level of lesion
BROWN SEQUARD SYNDROME
- damage on the dorsal column
- bilateral loss of position and vibration sense below the level of the lesion
Posterior Cord Syndrome
- from Syphillis
- Syndrome of the dorsal columns: progressive ataxia, proprioceptive loss, rombergism, incoordination, lancinating or lightning-like pains, Lhermitte’s sign
- Gastrointestinal, urinary and sexual dysfunction
- Loss of DTRs, Argyll Robertson pupils
TABES DORSALIS
- is a sudden sensation resembling an electric shock that passes down the back of your neck and into your spine and may then radiate out into your arms and legs. It is usually triggered by bending your head forward towards your chest
- usually seen in dorsal column problems (Multiple Sclerosis, Tabes Dorsalis)
Lhermitte’s sign
- small irregular and asymmetrical, fail to react to light but constricts on accommodation (light-near dissociation)»_space; tectum of midbrain proximal to oculomotor nuclei where the descending pupillodilator fibers are in close proximity to the light reflex fibers.
- responds to an accommodation effort but fails to react to direct light
Argyll Robertson pupil
Natural History and Progression
- Tabetic pain phase
- Ataxic phase
- Paralytic phase
Pathology
- Demyelination and rarefaction of posterior columns and dorsal roots with neuronal loss and gliosis
- Chronic inflammatory disease of DRG
TABES DORSALIS
- Insidious onset of paresthesias in hands and feet, Lhermitte’s sign, sensation of generalized weakness and fatigue, autonomic features
- Gait abnormalities due to combination of sensory ataxia and spastic paraparesis
- Weakness most prominent in legs
- affects the dorsal column and corticospinal tract
- Seen in people with vitamin B12 deficiency (cobalamin)
SUBACUTE COMBINED DEGENERATION
- Damage to spinothalamic fibers crossing in the ventral commissure causes bilateral regions of sensory loss to pain and temperature
- classic cape distribution
Central Cord Lesion (Small lesions)
- Anterior horn cell damage producing lower motor neuron deficits
- Corticospinal tract damage producing upper motor neuron deficits
- Posterior column damage producing vibration and proprioception deficits
Central Cord Lesions (Large Lesions)
- common cause of central cord lesion
- Fluid-filled cavity in the spinal cord
- Communicating vs. non-communicating
- Capelike distribution of dissociated sensory loss
- Further expansion: anterior horn cells, intermediolateral column (sympathetic pathways), corticospinal tract, posterior columns
SYRINGOMYELIA
- Preferential involvement of pain and temperature rather than vibratory or joint position sensation because of early segmental involvement of crossing spinothalamic tracts
SYRINGOMYELIA
- Lies within the vertebral canal and protected by three surrounding fibrous membranes – MENINGES
- Held in position by the DENTICULATE LIGAMENTS on each side and FILUM TERMINALE inferiorly
SPINAL CORD
- SEGMENTED and paired POSTERIOR / SENSORY and ANTERIOR / MOTOR ROOTS corresponding to each segment of the cord leave the vertebral canal through the INTERVERTEBRAL FORAMINA
- SHORTER than the vertebral column and terminates in the adult at the level of lower border of first Lumbar vertebra
SPINAL CORD
- Continuation of the most inferior part of the brain, the medulla oblongata. The medulla oblongata crosses the foramen magnum to continue as the spinal cord.
Spinal Cord
Spinal cord segments
- Cervical
- Thoracic
- Lumbar
- Sacral
Spinal Cord terminates at:
- Adult: lower border of L1-upper border of L2
- Newborn/children: L3-L4
The spinal cord is made-up of 2 main layers:
white mater (outside): is divisible into columns or funiculus, posterior, anterior, and lateral columns/funiculus
gray mater (inside): divisible into horns, the posterior/dorsal, anterior/ventral and in some segments, lateral horn
Posterior, Anterior and Lateral Horn
posterior and anterior horn: present in all segments
lateral horn: present only in thoracic and in upper lumbar
Dorsal and Ventral Horn
Dorsal horn: carries sensory information
Ventral horn: carries motor information
Fasciculus cuneatus v Fasciculus gracilis
fasciculus cuneatus: only on upper segments (cervical and thoracic)
fasciculus gracilis: present in ALL segments
THREE SULCUS TO REMEMBER:
- Anteromedian (ventromedian) fissure: separates R and L anterior columns
- Posteromedian (dorsomedian) sulcus: separates R and L posterior columns
o In some segments, the posterior column is further divided into 2 parts: fasciculus gracilis and fasciculus cuneatus. - Dorsointermediate (posterointermediate) sulcus: separates fasciculus gracilis and fasciculus cuneature
Shape: Oval
White Mater: Fasciculus Cuneatus and Gracilis present
Gray Mater/Lateral Horn: Absent
Cervical
Shape: Round
White Mater: Fasciculus cuneatus (T1 and T6) and Gracilis present
Gray Mater/Lateral Horn: Present
Thoracic
Shape: Round to oval
White mater: Fasciculus Cuneatus absent; Fasciculus Gracilis present
Gray Mater/Lateral Horn: Present
Lumbar
Shape: Round
White mater: Fasciculus Cuneatus absent; Fasciculus Gracilis present
Gray Mater/Lateral Horn: Absent
Sacral
Columns in the White Matter
- Posterior funiculus
- Lateral funiculus
- Anterior funiculus
Each column is subdivided into tracts. These tracts are:
- Ascending tract
- Descending tract
- Intersegmental tracts
Parts of the Gray Matter
- Posterior horn
- Lateral horn
- Anterior horn
*The cell bodies in the gray substance are grouped into clusters of nuclei of laminae.
(Laminae of Rexed - groupings)
- located in the posterior horn
Laminae I – VI
(Laminae of Rexed - groupings)
- located at the lateral horn
Lamina VII
(Laminae of Rexed - groupings)
- located at the anterior horn
Laminae VIII and IX
(Laminae of Rexed - groupings)
- gray substance surrounding the central canal
Lamina X
- Position sense
- 2 pt discrimination
- Fine, discriminative
- Vibration sense
- Stereognosis
Dorsal / Posterior Column
Spinothalamic tract
Anterior Spinothalamic Tract – touch / Proprioception
Lateral Spinothalamic Tract – pain and temp
Injury to the Ascending Tract will result to __
Sensory Loss
- Lateral corticospinal
- Rubrospinal
- Lateral reticulospinal
- Medial reticulospinal
- Vestibulospinal
- Tectospinal
- Anterior corticospinal
Descending Tracts
- Originates at the primary motor cortex
- Axons of pyramidal cells descend in the internal capsule
- Axons extend into the brainstem and spinal cord to synapse on lower motor neurons
PYRAMIDAL SYSTEM
Lateral Corticospinal Tract –at the lower medulla, axons decussate the midline to enter on the opposite side of the SC
Corticospinal Tract
The __ is from the brain down to the spinal cord that carries motor information thus, injury to it would result in paralysis (motor loss).
descending tract
If you have a lesion involving the dorsal column, are you going to have sensory loss? What type of sensory loss?
Yes, proprioception (a collective term for position sense, 2pt discriminative touch, vibratory sensation and stereognosis).
If you have injury involving the lateral spinothalamic tract, are you going to have sensory loss? What type of sensory loss?
Yes, pain and temperature.
If you have injury involving the anterior spinothalamic tract, are you going to have sensory loss? What type of sensory loss?
Yes, touch and pressure
Suppose you have a case, a lesion on the right dorsal column, where is the proprioception loss? Right side or left side?
Right side. Manifestation is always in the same side
If it is the corticospinal tract, are you going to have a motor loss? Yes or no? Upper or lower motor neurons?
- Yes
- A lesion involving the descending pathway from the primary motor area down to the descending pathways, we have an upper motor neuron lesion.
- A lesion involving the anterior horn cells to the outside the spinal cord, we have a lower motor neuron lesion.
- Recall the lecture on how to differentiate an upper motor neuron and a lower motor neuron lesion.
A lesion involving the dorsal column would lead to proprioception loss. The manifestation will always be on the __
same side
Injury to the spinothalamic tract, the manifestation will always be on the __
contralateral side
Rule in Localization (Ascending Tract)
First rule, ascending pathway = sensory information
Second rule, localization.
- Right dorsal column lesion, the manifestation is on the same side.
- Right spinothalamic tract lesion, the manifestation is on the contralateral side.
As a rule, injury to descending pathway will lead to motor loss, upper motor neuron lesion. The manifestation will always on the __ because our lecture is about spinal cord disorder.
same side
(Lesion of Corticospinal Tract)
Above the level of decussation, manifest __
e.g. Stroke involving right motor area of cerebrum- left sided paralysis
contralaterally
(Lesion of Corticospinal Tract)
Below the level of decussation, manifest __
- e.g. Spinal cord lesion on the right side- right sided paralysis
- Again, dahil spinal cord injury ang lecture, the motor loss is always on the same side of the injury
ipsilaterally
Sensory and motor loss on the spinal cord injury is always on the same side except on the sensation mediated by the __
spinothalamic tract
Descending pathways referred to as __
upper motor neurons
Motor cells in the anterior gray horn of the spinal cord and motor nuclei of the cranial nerves are the final common pathways for the control of skeletal muscle activity; referred to as __
lower motor neurons
Paralysis: Spastic Atrophy: (-) Fasciculations: (-) Clonus: (+) Pathologic Reflexes: (+) Muscle tone: Increased
Upper Motor Neuron Lesion
Paralysis: Flaccid Atrophy: (+) Fasciculations: (+) Clonus: (-) Pathologic Reflexes: (-) Muscle tone: Decreased
Lower Motor Neuron Lesion
When are we going to have sensory loss?
If we have involvement of the dorsal/posterior column and the spinothalamic tract.
When are we going to have motor loss?
If we have involvement of the corticospinal tract, descending pathway and the anterior horn cells
- In right hemisection, are you going to have sensory loss? Yes or no? What type of sensory losses?
- Is there motor loss? UMN, LNM or BOTH?
o There’s sensory loss. Both dorsal column and spinothalamic tract are involved.
o There’s motor loss. Both corticospinal tract and anterior horn cells are involved so UMNL and LMNL are involved.
Clinical Signs and Symptoms of Spinal Cord Disorders (In ER, abundant ang vehicular accidents. If you suspect that there’s spinal cord injury, what will you check?)
- Motor findings
- Sensory level
- Deep tendon reflexes
- Autonomics
How to differentiate SC from cerebral lesion because both will manifest a motor loss and sensory loss. How to rule out cerebral lesion?
- Level of consciousness and Orientation
- Ask the patient about pertinent information (i.e name, birthday)
- doing this you already ruled out cerebral lesion
Bilateral cervical spinal cord damage C4-C6 may result in
paralysis of all four extremities
quadriplegia
Unilateral spinal cord lesions in thoracic levels may result in
paralysis of the ipsilateral lower extremity
monoplegia
If the thoracic spinal cord damage is bilateral, both lower
extremities may be paralyzed
paraplegia
- is paralysis on opposite side.
- If the paralysis on the face is on the right side, the paralysis on the body is on the left side.
Hemiplegia
o Follows acute damage to the spinal cord; temporary interruption of the function of SC following injury
o All cord functions below the level of the lesion become
depressed or lost
o Persists for less than 24 hours or may persist for as long as
one to four weeks
Spinal Shock
o Can be determined by testing for the activity of the anal
sphincter reflex
o Flaccid, areflexic paralysis
o Complete loss of sensation
o Loss of autonomic function
o Loss of reflex activity-paralysis of the bladder and rectum
Spinal Shock
- loss of all sensations on both side and motor loss on both UMN and
LMN also on both sides - Complete loss of all sensibility and voluntary movement below the level of the lesion
Complete Cord Transaction
o all sensation loss except sensation mediated by the dosal column and motor loss on both UMN and LMN. All the rest is affected except the dorsal column.
o can be caused by cord contusion during vertebral fracture or dislocation, from injury to the anterior spinal artery or its feeder arteries with resultant ischemia of the cord, or by a herniated intervertebral disc
Anterior Cord
o loss of sensation - proprioception. All the rest is intact except dorsal
column
Posterior Cord
- no motor loss in small lesions. Sensory loss on sensation mediated by the spinothalamic tract.
Central Cord
o loss of all sensations and motor loss on both UMN and LMN also on one side only
Brown Sequard’s-Hemisection
DIAGNOSIS OF NEUROLOGIC DISORDERS
- Diagnosis of Neurologic Disorders
- Basic approach to the solution of problems—-Three questions must be answered:
- Is there a lesion involving the nervous system?
- Where is the lesion located?
- What is the histopathologic nature of the lesion?
- Spinal cord hemisection
- Features:
o Contralateral loss of pain and temperature
o Ipsilateral loss of proprioception
o Ipsilateral manifestations of upper and lower motor neuron
lesions
BROWN-SEQUARD’S SYNDROME
Dermatomes (Cervical)
C2 - back of head C5 - tip of shoulder C6 - thumb C7 - middle finger C8 - small finger
Dermatomes (Thoracic and Lumbar)
T4-T5 - nipple
T10 - umbilicus
L1 - inguinal
L4-L5 - big toe
Dermatomes (Sacral)
S1 - small toe
S5 - perineum
Complete cord Transection
- Motor loss (both upper and lower)
- Sensory loss (all sensation)
Anterior Cord Lesion
- Motor loss (upper and lower)
- Sensory Loss (spinothalamic tract only)
*ang intact lang ay DORSAL COLUMN, all the rest are affected
Posterior Cord Syndrome
- No Motor Loss
- Sensory Loss (Dorsal Column only)
*only affected is Dorsal Column
Central Cord Syndrome (Small)
- No Motor Loss
- Sensory Loss (spinothalamic tract only)
Brown Sequard’s (Hemisection)
- Motor Loss (upper and lower)
- Sensory Loss (both dorsal and spinothalamic)
- Loss of PAIN AND THERMAL sensations on the CONTRALATERAL side about 1-2 SEGMENTS BELOW the level of the lesion
o Example: T8 on the right – Loss of pain/temperature at T10 dermatome on the left side
o Damage at the T6 level would result in loss beginning at the T8 level on the contralateral side; T10 level damage = loss at beginning of T12 level
ANTEROLATERAL SYSTEM
– caused by neurosyphilis; dorsal root involvement with secondary degeneration of dorsal columns ( loss of vibration and position sense)
Tabes Dorsalis
Clinical Signs of Injury to the Lemniscal Pathway
- Inability to recognize limb position
- Astereognosis
- Loss of two point discrimination
- Loss of vibration sense
- (+) Romberg sign
- A patient who can stand with feet together and the eyes open, but who sways and falls when the eyes are closed – (+) Romberg sign
- Indicates an absence of position sense in the lower limbs
Romberg Sign
– progressive cavitation around the central canal; loss of pain and temperature sensations in hands and forearm ( common in cervical)
- Dissociated sensory loss but proprioception sensation is intact
Syringomyelia
– attacks the anterior horn cells leading to Lower Motor Neuron Lesion
Poliomyelitis
– caused by neurosyphilis; dorsal root involvement with secondary degeneration of dorsal columns (loss of vibration and position sense)
Tabes Dorsalis
– pure motor disease involving the degeneration of anterior horn cells (LMNL) and corticospinal tract (UMNL); NO sensory loss
Amyotrophic lateral sclerosis
– caused by vitamin B12 deficiency; degeneration of posterior and lateral columns ( loss of position sense and vibration in legs associated with UMNL)
Subacute combined degeneration
