Module 7 Flashcards by Enn Cee

continuous with meninges of brain, protect spine, carry blood supply
surrounds the spinal cord

Meninges

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tough fibrous tissue; epidural space: contain loose connective tissue and adipose, anesthetic injection site

Dura mater

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simple squamous epithelium; subarachnoid space is filled with CSF and contains trabeculae (collagen/elastin fiber network)

Arachnoid

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bound to spinal cord; made of collagen and elastic fibers

Pia mater

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extend from pia to dura matter and stabilize side to side movements
gives stability of the cord

Denticulate ligaments

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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

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Thoracic, Lumbar, Sacral may have a __.

lateral horn

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Sympathetic vs Parasympathetic

At the level of your thoracic T1 to L2 that will be your sympathetic outflow.

S1-S4 parasympathetic outflow.

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Potential Spaces in the Spinal Cord

Epidural Space - filled with fat
Subdural Space
Subarachnoid Space - contains CSF

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Blood Supply of the Spinal Cord

two posterior spinal arteries to support the posterior part
one anterior spinal artery

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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)

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Cervical and Lumbar Part

Cervical and Lumbar part are fatter because they serve the limbs; means more nerve bodies

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part of the pia mater; goes down and attaches itself to the coccyx

Filum Terminale

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space that is created where there is no more cord is occupied by __

Cauda Equina

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this cord will go out above the vertebral body

C1-C7

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cords that will exit below the vertebral body

C8 going down

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usually have a discrepancy of about 2 segments

- eg T4 vertebra will correspond to T6 spinal cord segment

Upper half of the thoracic

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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

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limited only for the sensory which is the dorsal column

Posterior

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9 cell layers or laminae:

1-6 dorsal,
7 intermediate,
8-9 ventral

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separate dorsal gray column from surface of spinal cord

Zone of Lissauer

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axons contribute to lateral spinothalamic; pain temp

Nucleus posterior marginalis

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pain, temp, light touch; contribute axons to lateral and ventral spinothalamic; have Mu and Kappa opioid receptors;

Substantia gelatinosa (II)

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fine touch and proprioception; pain and temp; contribute to lateral spinothalamic, ventral spinocerebellar

Nucleus proprius (III,IV,V)

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- 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

- 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)

1. Spinal tract and Nucleus of V: pain and temperature sensation at the level of the medulla 2. Chief sensory nucleus of V: vibration, proprioception and light touch/tactile discrimination 3. 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) >> 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

(Dermatomes) T4

Nipple

(Dermatomes) | T10

Umbilicus

(Dermatomes) Groin

(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) >> 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:

1. Anteromedian (ventromedian) fissure: separates R and L anterior columns 2. 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. 3. 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