Primary Mechanisms that Mediate Tone

• Normal 
• High 
• Low

the right amount of tension inside the muscle at rest

    High tone

too much tension in the muscle at rest- it is tight and tense even when not doing anything

Occurs when increased muscle tone results in jerky movements throughout. Type of Abnormal Response

Stiff throughout the movement, like trying to bend a piece of wire. Type of Abnormal Response

stereotypes set of movement that occurr in responses to a stimulus or voluntary movement. Involve pathology of muscle tone that affects joint position after neurologic damage, such as TBA or CVA. Described as patterns. 

• Elevation and Retraction
• Protraction and Depression

Scapula 

• Flexor Synergy Pattern
• Extensor Synergy Pattern

• Abduction and external rotation
• horizontal adduction and internal rotation

  Shoulder

• Flexor Synergy Pattern
• Extensor Synergy Pattern

• Flexion
• Extension and pronation

Elbow

• Flexor Synergy Pattern
• Extensor Synergy Pattern

• Supination
• Pronation

Forearm

• Flexor Synergy Pattern
• Extensor Synergy Pattern

• Flexion and ulnar deviation
• extension

Wrist

• Flexor Synergy Pattern
• Extensor Synergy Pattern

• flexion and adduction
• flexion and adduction

• Fingers 

  • Flexor Synergy Pattern
  • Extensor Synergy Pattern

• flexion and adduction
• flexion and adduction

Thumb

• Flexor Synergy Pattern
• Extensor Synergy Pattern

• flexion, abduction, and external rotation
• extension, adduction, and internal rotation

Hip 

• Flexor Synergy Pattern
• Extensor Synergy Pattern

• flexion
• extension

knee

• Flexor Synergy Pattern
• Extensor Synergy Pattern

• dorsifelxion and inversion
• plantar flexion and inversion

Ankle

• Flexor Synergy Pattern
• Extensor Synergy Pattern

• dorsifelxion
• plantar flexion

Toes

• Flexor Synergy Pattern
• Extensor Synergy Pattern

Associated Reactions

Therapy interventions for abnormal tone

Bony Labyrinth 

3 semicircular canals (Anterior, Posterior, Lateral) ▶ Cochlea ▶Filled with Perilymphatic fluid

 Bony Labyrinth 

3 semicircular canals (Anterior, Posterior, Lateral) ▶ Cochlea ▶Filled with Perilymphatic fluid

high Na:K ratio communicates with CSF through the cochlear adqeduct)

 Membraneous Labyrinth

▶ Suspended within the bony labyrinth

▶ Membraneous  portions of the semicircular canals and the otolith organs

▶ Filled with endolymphatic fluid

• (high K:Na ratio)

 Outer ear

▶ Ear (Pinna) ▶Ear canal 

Structures of what part of the ear

Middle Ear

▶The ear drum (tympanic membrane) ▶The three (3) small bones

•malleus •Incus •stapes

Structures of what part of the ear?

▶Peripheral vestibular System

•Semicircular Canals •Otoliths (utricle and saccule) •Vestibular nerve

Structures of what part of the ear?

Auditory Portion

•Cochlea •Cochlear Nerve

Structures of what part of the ear

Superior and inferior

2 parts of the auditory nerve

Lateral canal 

Superior Canal

Utricle

3 parts of superior vestibulocochlear nerve

Posterior Canal

Saccule

2 parts of inferior vestibulocochlear nerve

Respond to a change in

velocity

• Anterior Canal

– Angle of the canal:

entrance/exit of the canal:

approximately 70deg

• Posterior Canal

– Angle of the entrance/exit

of the canal: approximately 30deg

• Horizontal Canal

– Sits 30 degrees above

horizontal

 Kinocilium larger hair cell

• Sterocilia smaller hair cells

What 2 things do hair cells consist of and which one is longer and which one is shorter?

1. excites
2. inhibits

1. Deflection of hair cells towards the

kinocilium ______ CN VIII.

•  Deflection of hair cells away from

the kinocilium ______ CN VIII

When the head turns to the right, which way does the fluid move?

1. Left
2. Sreeocilia on the right side move toward the kinocilium causing excitation n the Right
3. Stereocilia on the left side move away from the kiniocilium causing inhibition on the LEFt

1. When the head turns to the right, which way does the fluid move?
2. Which way do the stereocilia on the right side move?
3. Which way do the stereocilia on the left side move?

Posterior-Inferior Cereellar Arteries

• Most important arteries of central vestibular structures • Inferior portions of cerebellar hemispheres • Dorsolateral medulla (inferior aspects of the vestibular

nuclei)

 Anterior inferior cerebellar arteries

Most important & sole vascular supply for the peripheral

vestibular system via the labyrinthine artery • Ventrolateral cerebellum • Lateral tegmentum and lower 2/3 of pons

• Medial pons • Anterolateral pons • Dorsolateral pons

 Central Pathlogies 

Cerebellar degeneration

• Multiple sclerosis

• Encephalitis

• Tumor

• Hematoma

• Vestibular Migraine

• Vascular disease

• Stroke

• Concussion

Peripheral Pathologies

Acoustic neuroma

▶ Vestibular Schwanoma

▶ Vestibular neuritis

▶ Vestibular Labrynthitis

▶ Meniere’s Disease

▶ Benign Paroxysmal Positional

Vertigo (BPPV)

▶ Perilymph Fistula

▶ Superior Semicircular Canal

Dehiscence

▶ Concussion

Substitution

Habituation

Adaptation

3 types of therapy persepctives

Substitution

Type of therapy solution

use of other strategies or adaptive equipment to replace lost function or improve upon stability

 Habituation 

Type of Therapy Solution

 repeated exposure to a stimulus will result in a reduction of the pathological response to that stimulus. Therefore, diminishing dizziness in patients who have movement-provoked symptoms

 Adaptation

Type of Therapy Solution

long-term neuro plastic changes that occur in response to stimulation of the vestibular system

• Central Cord Syndrom Etiology

• unknown
• more commonly occurs in elderly persons who have norrowing, or stenotic, changes in the spianl canal realtd to arthritis 
• damage may also occur in people with congenital stenosis

Central Cord Syndrome

Pathology

• involves a cavitation of central cord in cervical segments

• spinothalamic tracts are first to be lost because they synapse in the dorsal horn and decussaet to the anterior white funiculus as soon as the enter the cord. 
• the ventral horn is lost which results in flaccidity of the upper extremities bc the disease occurs in the cervical region of the SC

• disease process hat destroys the MNs in the ventral horn

Anterior Horn Syndrome (Patholoy)

• involved LMN damage

• Results in bilateral flaccidity in the muscles innervated by the affected SC levels
• example is poliomyelitis, an acute viral disease that affects the ventral horn motor cell bodies

• infarct
• ischemia
• trauma

• occurs when 2/3rds of the anterior cord is lodt

• dorsal columns are spared (discriminaitive touch, vibration, pressure, and proprioception are spared)
• lateral corticospinal tracts are lost bc they descend doen the lateral white funiculus
• results in bilateral spastic paralysis
• patient loses bilateral voluntary motor control below level of lesion
• spinothalamic tracts are lost bc the synapse in the dorsal horn and decussate across the white anterior funiculus as soon as they enter the SC. 
• Patient has bilateral loss of pain and temp sensation

• MS
• Stab Wound
• Tumor

• dorsal columns are lost bilaterally

• the lateral corticospianl tract is lost ipsilaterally 
• patient presents with ipsilateral loss of motor control and spasticity below the level of lesion and ipsilateral flaccidity at level of lesion
• dorsal column is lost ipsilaterally
• patient prsesnts with ipsilateral loss of discriminative touch, pressure vibration and proprioception
• spinothalamic is lost contralaterally 
• patient presents with paina nd tmeperature sensation loss on contralateral side
• at level of lesion, patient experiences bilateral loss of pain and temp sensation

• degeneration of the SC from severe Vitamin B12 deficiency, pernicious anemia or AIDS

Posterolateral Cord Syndrome (Pathology)

• affects the posterior and posterolateral white funciluli of SC

• dorsal columns are lost bilaterally 
• results in bilateral loss of discriminative touh, pressure, vibration and proprioception
• lateral corticospinal tracts are lost bilaterally
• results in bilateral spastic paralysis
• spinocerbellar tracts are lost
• results in bilateral ataxia

• seen in patients with neurosyphilis

• dorsal columns are lost bilaterally

• causes bilateral loss of tactile discrimination, vibration, pressure, and proprioception (often accompanied by ataxia)

Afferent information from skin, muscles and/or joints can 

Both segmental and vertical tract function or just

segmental function or just vertical tract function

Anterior cord syndrome, central cord syndrome, brown Sequard syndrome (hemisection), Cauda equina Syndrome, Tethered cord syndrome

Is usually caused by motor vehicle accidents, sports injuries, falls, or penetrating wounds.

First three types of injuries typically do not sever the spinal cord; damage is due to 

Penetrating wounds, by a knife or a bullet, directly    

After Traumatic Spinal Cord Injury

Neural control of the pelvic organs is depressed.

Percentage of people with differing ASIA scores are able to walk at time of discharge from hospital.

Complete- no motor or sensory function is preserved in the sacral segments S4-S5

Percentage of people with differing ASIA scores are able to walk at time of discharge from hospital.

Incomplete-sensory but not motor function is preserved below the neurologic level and includes the sacral segments S4-S5

Percentage of people with differing ASIA scores are able to walk at time of discharge from hospital.

Incomplete motor function is preserved below the neurologic level, and more than half of key muscles below the neurologic level have a muscle grade less than 3

Percentage of people with differing ASIA scores are able to walk at time of discharge from hospital.

Incomplete- motor function is preserved below the neurologic level, and at least half of key muscles below the neurologic level have a muscle grade of 3 or more.

Disorders in addition to traumatic SCI that interfere with spinal region function 

Signs and symptoms that indicate a spinal cord lesion    

Signs and symptoms that indicate a possible cauda equina lesion 

Pupillary, Consensual, and Accommodation Reflexes    

constriction of the pupil in the other eye   

Vestibulocochlear Nerve and Disorders of the Auditory System    

form of low blood pressure that occurs when a patient goes from a lying or sitting position to standing or sitting.

Symptoms:

• Feeling lightheaded/dizzy with standing from seated position

• Blurry vision

• Weakness

• Fainting

• Confusion

• Nausea

• Triggered by:

  • Mild dehydration

  • Low blood sugar

  • Overheating

Can’t regulate one's body temperature

Happens when the ANS is damaged (sympathetic)

Often co-occurs with orthostatic hypotension

The higher the level of injury, the more severe the dysregulation

Symptoms:

• Baseline body temperature measures in the 96s and 97s or sometimes lower

• Temperatures can drop lower throughout the night

• Less often, baseline temperatures run higher than normal

• Inability to tolerate heat/cold

• Urinary problems

• Dizziness/fainting

• Vision problems

• Can’t regulate heart rate

• Sweating abnormalities

Triggered by:

• Spinal cord injuries

• Hypothalamus injury

• Fibromyalgia

• Diabetes

• Parkinson’s

• Long-term heavy drinking

• Uncontrolled high blood pressure

• Lyme’s disease

Disorders of bowel and Bladder

Causes: spinal cord injury (ALS, MS, spina bifida)

Symptoms

1. above the conus medullaris (UMN bowel syndrome, UMN bladder syndrome)

- Loss of voluntary control

- Constipation

- increased anal tone

2. At or below the conus medullaris (LMN bowel/bladder syndrome)

Bladder:

- Incontinence means loss of bladder control

- Loss of voluntary control

- Inability to empty the bladder

- Urinary frequency increased

- UTI

Bowel:

- Loss of bowel control

- Bowel frequencies increased

- Prolonged transition time

- Constipation

- Rectal impact

- Reduced resting tone in anal sphincter

- Inability to relax muscles to allow voiding

A spinal cord injury at the thoracic level: SCI causes autonomic dysreflexia.

The sacral plexus is implicated in voiding with the pudendal and pelvic splanchnic nerves involved; the resulting symptom is incontinence. In spinal cord injury with injury to S2-S4 the splancnic nerve is affected. Parasympathetic neurons reach the pelvic viscera and distal colon with innervation to most of the gut comes from the cranial nerve X the Vagus nerve.

Autonomic Dysreflexia

considered a medical emergency, characterized by acute uncontrolled hypertension and high blood pressure at a dangerous level. There is vasodilation of the blood vessels above the level of the injury and vasoconstriction below, which is the body’s attempt to counteract the high blood pressure. It is developed in individuals with a spinal cord injury at or above the vertebral level of T6.

Symptoms may include bradycardia, tachycardia, high blood pressure, anxiety, blurred vision, headache, flushed skin, sweating, pupillary constriction, nasal congestion, and blotchy skin. Below the level of injury, additional symptoms are pale skin and piloerection. If left untreated, side effects include seizures, retinal hemorrhage, pulmonary edema, renal insufficiency, myocardial infarction, cerebral hemorrhage, and possibly death. These side effects are commonly seen in children.