L5: Sensorimotor Impairments After ABI

Somatosensation is considered in a general sense because

Receptors are not associated with a specialized organ, but are instead spread throughout the body in a variety of organs

What sensory modalities are somatosensation associated with

• Touch

• Proprioception

• Interoception

Many somatosensory receptors located in the ________

Skin

Besides skin, where else can somatosensory receptors be found

• Muscles

• Tendons

• Joint capsules

• Ligaments

• Walls of visceral organs

What is detection

The threshold activation of a peripheral sensory receptor

What is localization

Awareness of specific location of stimulation

What is discrimination

Integrative evaluation of sensory characteristics

Tactile somatosensation has a ________ depth

Superficial

Receptors in the ________ detect tactile somatosensation

Skin

Proprioceptive somatosensation has a ________ depth

Deep

What is proprioception

• Position or movement of a joint or body segment

  • Muscle length

• Detected by

  • GTOs

  • Muscle spindles

What are detection somatosensations

• Sharp/dull

• Temperature

• Light-touch

• Pressure

What are discrimination somatosensations

• Vibration

• Localization

• Two-point discrimination

• Graphesthesia

• Stereognosis

• Proprioception/kinesthesia

Vibration

oscillating object

Localization

Where stimulus is applied

• Distance error between where touched and where felt

Two point discrimination

Distinguishs between 2 blunt stimulus

Graphesthesia

Write on pt

• Recognize symbols/shapes

Stereognosis

Ability to ID object via touch

Proprioception/kinesthesia

Where you are in space

What does the dorsal column medial lemniscus detect

Fine touch, vibration, proprioception

What is the 1st order neuron of DCML

Dorsal root ganglia

What is the 2nd order neuron of DCML

Nucleus gracilis or cuneatus

What body region is nucleus gracilis associated with

• Lower extremity

  • Below T6

What body region is nucleus cuneatus associated with

• Upper extremity

  • Above T6

What is the 3rd order neuron of DCML

VPL

Where does DCML decussate

Lower medulla

What is the anterior spinothalamic tract 1st order neuron

DRG

What is the anterior spinothalamic tract 2nd order neuron

Substantia gelatinosa or nucleus proprius

What is the 3rd order neuron of the anterior spinothalamic tract

VPL

Where does the anterior spinothalamic tract decussate

Anterior white commissure

Where does the anterior spinothalamic go to in the brain after VPL

• S1

• Insula

• Anterior cingulate cortex

Where are the sacral vs cervical fibers located

• Sacral = lateral

• Cervical = medial

What deficits may be present from brainstem lesion? How will they present

CN deficits

• ipsilateral, bilateral, or contralateral

What deficits might be present with thalamus lesion? How will they present

sensory and motor deficits

• VPL = sensory and motor

• Contralateral

What deficits might be present with cortical lesion? How will they present

Relatively focal deficits

• Homunculus

• Contralateral

How might hyposensitivity present

• Anesthesia

• Reduced response/hypoesthesia

• Sensory neglect

What is anesthesia

No sensation at all

What is sensory neglect

Not attending to sensations applied to one side of the body

What are the safety concerns with hyposensitivity

• Burns

• Pressure ulcers

• Leave arm behind/ischemia

• Infection

How might hypersensitivity present

• Sensory defensiveness

• Sensory avoidance

• Paresthesia

What is sensory defensiveness

Reactive to sensory input

What is sensory avoidance

Avoid input to sensory stimulus

What is paresthesia

Abnormal negatively perceived sensation that may include burning, pricking, tickling, tingling, or numbness without apparent cause

What does hypersensitivity and hyposensitivity impact

• Motor skills

• Posture/balance

• Motor learning

What should you include when you are defining quantity of sensory impairment

Extent, sizeM and regional dimensions of deficit

• Boundaries

• Regional distribution = unilateral, paraplegic/tetraplegic, dermatomal, peripheral nerve, general peripheral neuropathy

How do sensory deficits associated with brain injury typically occur (what distribution)

Unilateral distribution

How many stroke survivors report somatosensory deficits

50-80%

What are the most commonly reported sensory deficits

• Proprioception

• Stereognosis

What do the patients report difficulty with due to altered somatosensation and what are the results from this

Dfficulty in using involved limbs

• Results in use of compensatory strategies and lack of sensory retraining

What are the consequences of impaired somatosensation

• Impaired motor control/recovery

• Injury risk

• Increased incidence of incontinence

• Decreased participation

How might vision be affected by ABI

• Decreased visual acuity

• Dysfunctional eye movement

• Visual field loss

What is decreased visual acuity

Loss of central vision leads to blurred or altered vision

How long might someone experience decreased visual acuity

May be permanent

How many people do visual perceptual abnormalities affect post stroke

1/3 people

How might visual perceptual abnormalities present

• Neglect one side of body

• Difficulty recognizing faces/objects

• Difficulties with color vision

• Depth perception

Dysfunctional eye movements are more common in ________

TBI

How might dysfunctional eye movements present

• Strabismus

• Difficulty with convergence

• Diplopia

Why might someone have dysfunctional eye movement

CN being affected

• CNs III, IV, VI

Visual field loss more often affects people who have had a ________

Stroke

How might visual field loss present

Homonymous hemianopia

What sided lesion is homonymous hemianopia more typical with

Right sided lesion

What side of the visual field will be lost with homonymous hemianopia

Contralateral to lesion

What are all the components of motor function

• Muscle strength

• Muscle tone

• Muscle endurance

• Muscle activation

• Motor control

What is muscle strength

The ability to generate force

What is muscle tone

An inherent amount of muscle activity

What is muscle endurance

The capacity to sustain work

What is muscle activation

Amount/timing of muscle activity

What is motor control

Organization and regulation of movement

What must occur to perform traditional strength testing in the neuro population

Ability to activate muscle properly without substitution or movement compensation

What might impact the ability to accurately strength test

• Synergistic patterns

• Spasticity

• Dystonia

What is the modified tardieu scale used for

Grading spasticity, including clonus

Tardieu Grade 0

No resistance throughout the course of passive movement

Modified Tardieu Scale Grade 1

Slight resistance throughout the course of passive movement, with no clear catch at precise angle

Modified Tardieu Scale Grade 2

Clear catch at precise angle, interrupting the passive movement, followed by release

Modified Tardieu Scale Grade 3

Fatigable clonus (<10 seconds when maintaining pressure occuring at precise angle)

Modified Tardieu Scale Grade 4

Infatigable clonus (>10 seconds when maintaining pressure occuring at precise angle)

What is the modified ashworth scale used for

Grading tone

Modified Ashworth Scale Grade 0

No increase in tone

Modified Ashworth Scale Grade 1

Slight increase, manifested by a catch and release or minimal resistance only at end of ROM when moved into flexion/extension

Modified Ashworth Scale Grade 1+

Slight increase, manifested by catch followed by minimal resistance detected throughout remainder of ROM (less than half of full joint ROM)

Modified Ashworth Scale Grade 2

More marked increase in muscle tone detected through most ROM but affected part moved easily

Modified Ashworth Scale Grade 3

Considerable increase in muscle tone, passive movement difficult

Modified Ashworth Scale Grade 4

Affected part rigid in flexion and extension

How else may we evaluate tone?

• DTR

• Pendulum Test

• Pronator Drift Test

• Arm Drop Test

What is the pendulum test

• Seated passive knee extension then drop leg

  • Normal = leg swings when you let go

  • Increase in tone = leg drops and catches

What is the pronator drift test

• Shoulder to 90° flexion and supination

  • Drift into pronation, elbow, wrist, finger flexion

What is the arm drop test

Passive shoulder abduction to 90° then drop arm

Ways to evaluate muscle endurance

• 6 MWT

• 30 sec STS

• Table push ups

• Bicep curls

• Isokinetic assessment

How might you evaluate muscle activation

EMG

How might you evaluate motor control

• SCALE - selective control assessment of LE

• Observational movement analysis

• Coordination testing (rapid alternating movements, etc)

• Selective motor control - isolate movement in a joint

• Fractionation- move through small ROM

• 9 hole peg test

What areas of the brain may have a lesion to interrupt motor dysfunction

• Pyramidal system

• Basal ganglia

• Cerebellum

• Internal capsule

• Brainstem

What tracts are associated with the pyramidal system

• Corticospinal

• Corticobulbar

What motor deficits may be present with lesion of pyramidal system

• Paresis

• Impaired motor control

• Hypotonia (early)

• Spastic hypertonia (late)

What motor deficits may be present with lesion of basal ganglia

• Dystonia

• Rigid hypertonicity

• Hyperkinesia

• Hypokinesia/bradykinesia

• Impaired motor control

• Involuntary movement

How might dystonia present

Rigid posture

• Fixed position

Why might someone have hyperkinesia with basal ganglia lesion

D1 pathway

Why might someone with basal ganglia lesion have impaired motor control

Lose key pathway for coordinating movement

Motor deficits with cerebellar lesion

• Muscle incoordination/ataxia

• Hypotonia

• Asthenia

• Diminished postural equilibrium

• Nystagmus

• Speech disturbance

What is asthenia

Lack of strength or energy loss

What falls under the ataxia umbrella

• Dysdiadochokinesia

• Ataxia

• Dysmetria - hypermetria or hypometria

• Hyperkinesias

• Speech disturbances