Patho Final - Neurological Disorders

What is the difference between a pain threshold and pain tolerance?

The pain threshold is the point at which a stimulus is perceived as painful, whereas pain tolerance is the maximum intensity/duration of pain that a person is willing to withstand before the person wants something done about the pain

What is nociceptive pain vs. neuropathic pain?

Nociceptive: nociceptors (pain receptors) are activated in response to actual or impending tissue injury

Neuropathic: direct injury to nerves

S/S of neuropathic pain

• Allodynia (pain from non injurious stimuli to skin)

• Hyperalgesia (extreme sensitivity to pain

• Analgesia (no pain in the presence of normally painful stimuli)

Cutaneous/Subcutaneous Pain

• From superficial structures

• Sharp, burning

• Can be accurately localized

Deep Somatic Pain

Deep in body structure

Visceral Pain

• Pain in visceral organs

• Diffuse

• Poorly localized

Referred Pain

Pain perceived at a site different from its origin; Innervated by the same spinal segment

How is pain classified?

• Duration (acute vs. chronic)

• Location (cutaneous vs. deep/visceral

• Site of referral (pain perceived at different spot)

• Associated medial diagnosis (expected pain)

Is pain subjective or objective?

Subjective

Acute Pain

• Signal of tissue damage

• Short duration

• CNS stimulation

• Less emotional effect

Chronic Pain

• No useful purpose

• Lasts longer than reasonably expected

• Persistent stimulation of nocioreceptors

• Complex psychosocial effects (deep depression)

What are nonpharmacologic interventions for pain management?

• Cognitive-behavioral

• Physical agents

• Stimulus induced analgesia

• Acupuncture/acupressure

• Back rubs

• TENS (transcutaneous electrical nerve stimulation)

• Biofeedback

• Distraction/relaxation

What would you use for pharmacologic treatment of pain?

• Nonnarcotic analgesics (NSAIDS, acetaminophen, ASA → block pain impulses)

• Narcotic analgesics (opioids, morphine, codeine → most effective when given before pain escalates)

• Anticonvulsants (Neuropathic pain → gabapentin)

• Topical (fentanyl patch)

What can happen as a result of taking opioids?

• Analgesia

• Respiratory depression

• Reduced gastric motility

• Vasodilation

• Euphoria

• Physical dependence

• Opioid tolerance

• Opioid naive

What are the two types of neuralgia?

• Trigeminal (face)

• Postherpetic (shingles rash)

What are you checking in an assessment of motor function?

• Body position

• Involuntary movements

• Characteristics (strength, size, tone)

• Spinal reflex activity

• Coordination of movement

Paralysis

Loss of movement

Paresis

Weakness

Plegia

Stroke or paralysis

Mono-

One limb

Hemi-

Both limbs on one side

Di- or para-

Both upper limbs or both lower limbs

Quadri- or tetra-

All four limbs

Hypotonia

Less muscle tone than normal

Flaccidity

Absent muscle tone

Terms for higher than normal muscle tone

• Hypertonia

• Rigidity

• Spasticity

• Tetany

What are characteristics of upper motor neuron damage?

• Weakness and loss of voluntary motion

• Pyramidal motor syndromes

• Damage to cerebral cortex, brainstem, spinal cord

• Spinal reflexes in tact; not modulated by brain

• Hypertonia

• Hyperreflexia

• Spasticity

Characteristics of lower motor neuron damage

• Neurons directly innervating muscles are affected

• Impaired voluntary/involuntary movement

• Spinal reflexes are lost

• Flaccid paralysis

• Denervation atrophy of muscles

What is happening in muscular dystrophy?

• Progressive degeneration and necrosis of skeletal muscles

• Contractile proteins not properly attached to cell membrane of muscle cell

• protein movement doesn’t effectively contract muscle cell

S/S of muscular dystrophy

• History of motor development delay

• Clumsiness

• Frequent falls

• Difficult climbing stairs, running, riding tricycle

• Waddling gait

• Ambulating usually impossible by 12

Biggest risk of muscular dystrophy

As breathing muscles become more affected, life-threatening infections are common → death by age 15-18

What neurotransmitter is effected in a neuromuscular junction problem?

ACh (decreased release and effect)

What is disorder is a neuromuscular junction problem?

Myasthenia Gravis

S/S of Myasthenia Gravis

• Gradual development of weakness from proximal to distal portions of body

• Droopy eyelid and mouth

• Difficulty swallowing

• Double vision

• Unsteady walk

What is the biggest risk with myasthenia gravis?

Myasthenia crisis → respiration compromised → death

What kind of injury is Guillain-Barré syndrome?

Polyneuropathy / Peripheral Nerve Injury

Risk factors for Guillain-Barré syndrome

• Possibly autoimmune

• Association with immunizations

• Frequently preceded by mild respiratory or intestinal infection

Manifestations of Guillain-Barre Syndrome

• Weakness

• Ataxia

• Bilateral paresthesia → paralysis

Begins in LE and ascends bilaterally

What does Guillain-Barre Syndrome cause problems with?

• Respiration

• Talking

• Swallowing

• Bowel and bladder function

What is back pain often caused by?

• Peripheral nerve injury at the spinal nerve roots

• Compression of nerve root by vertebrae or the vertebral disk

Manifestations of ruptured intervertebral disk

• Sensory deficits (spinal nerve root compression → paresthesias and numbness of specifically leg and foot)

• Knee and ankle reflexes also may be diminished or absent

• Motor weakness

What is the physiological cause of Parkinson’s?

• Progressive disease f the basal ganglia

• Dopamine depletion

Manifestations of Parkinson’s

• Tremor

• Rigidity

• Bradykinesia

• Loss of postural reflexes

• Autonomic system dysfunction

• Dementia

• Mask-like facial expression

• Arms flexed at elbows and wrists

• Hips and knees slightly flexed

• Short, shuffling steps

Manifestations of Amyotrophic Lateral Sclerosis (ALS)

• Damage to upper and lower motor neurons

• Muscle cramps (early)

• Progressive weakness and atrophy of one UE

• Regional spread of muscle weakness including respiratory

• Weakness of palate, pharynx, tongue (late) → dysphagia + aspiration

Multiple Sclerosis

• Progressive

• Autoimmune

• Demyelination of nerve sheaths

• Steroids for acute phases

S/S of Multiple Sclerosis

• Vision: involuntary eye movement and alignment, vision loss, double vision

• CNS: fatigue, cognitive impairment, depression, unstable mood, hearing loss

• Throat/speech: slurring, stuttering, dysphagia

• Sensory: heightened pain, reduced sense of touch, constant tingling/burning sense

• Digestion: incontinence, diarrhea

• Muscular: muscle atrophy, muscle spasms, lack of muscle coordination

Where does paralysis happen when you get a spinal cord injury?

• Below the level of injury

• Injuries above C4 → quadriplegia and paralysis of respiratory muscles

• Higher the injury, greater loss of function

What problem would you see for a lower spinal cord injury?

Temperature regulation problems

What does immediate damage from a spinal cord injury cause?

• Spinal shock (temporary or complete loss of function below injury)

• Primary neurological injury (irreversible damage to neurons)

What is autonomic dysreflexia? What triggers it?

• SPI at T6 or higher

• Triggered by restrictive clothing, full bladder or UTI, pressure areas, fecal impaction

S/S of autonomic dysreflexia

Above injury

• Flushed face

• Elevated BP

• HA

• Distended neck veins

• Decreased HR

• Diaphoresis

Below injury

• Pale

• Cool

• Non-diaphoretic

What can happen if autonomic dysreflexia Isn’t treated?

• Convulsions

• LOC

• Death

Mechanisms of brain injury

• Trauma

• Infections

• Tumors

• Degenerative Processes

• Metabolic Derangements

Manifestations of Brain Injury

• Changes in LOC (confusion, delirium, obtundation, stupor, coma)

• Nonreactive and dilated pupils

• Abnormal flexion and extension posturing + rigidity

• Respiratory changes (yawning, sighing, Cheyenne-Stokes breathing)

Ischemia consequences

• Decreased energy delivery

• Blood vessel damage (vasomotor paralysis, vasoconstriction)

• Changes in blood (desaturation, clotting, sludging)

What are the two types of brain edema?

• Vasogenic: extracellular fluid

• Cytotoxic: intracellular fluid

Hydrocephalus and Tx

• Progressive enlargement of the ventricular system from increased CSF

• Tx: Shunt

Causes of primary traumatic brain injuries

• focal lesions (contusions, hemorrhage)

• Diffuse injuries (concussion, diffuse axonal injury)

Causes of secondary traumatic brain injuries

• Brain swelling

• Infection

• Ischemia

Characteristics of hematoma in the epidural space

• Rapid bleeding

• Unconsciousness

• Brief lucid period

Characteristics of hematoma in dura mater

• Slower bleeding

• Gradual development over days-weeks

Traumatic Intracerebral Hematoma

• Most common in frontal or temporal

• More frequent in older persons or alcoholics

• Increased ICP

Manifestations of post-concussion syndrome

• Chronic traumatic encephalopathy (HA, poor memory)

• Second impact syndrome

Diffuse Axonal Injury

• Acceleration/deceleration or rotational forces (axonal damage)

• Shearing, stretching, or tearing of nerve fibers

Ischemic strokes

• transient ischemic attacks (brain angina)

• Large vessel (thrombotic)

• Small vessel (lacunar infarct)

• Embolic (clot from another area travel to brain)

Tx for ischemic stroke

Tissue Plasminogen Activator (within time window)

What is a hemorrhagic stroke?

Rupture of vessel → HTN

Risk factors and deficits of stroke

• Age, sex, race

• Family hx

• HTN

• Smoking

• DM

• Asymptomatic carotid stenosis

• Sickle cell disease

• Hyperlipidemia

• Afib

• Stroke related deficits (motor deficits, dysarthria and aphasia, cognitive and other deficits)

3 steps to stroke recognition

• smile and stick out tongue

• Make a complete sentence

• Raise both arms

What is a seizure?

Abnormal, excessive nerve firing

What can provoke a seizure?

• Fever

• Metabolic imbalances

• Brain injury (tumors, drug abuse, vascular lesions)

What is an unprovoked (epileptic) seizure?

Cause is unknown

Focal seizure w/o impairment

No impairment of consciousness or awareness; limited to one hemisphere

Focal seizure with impairment of consciousness or awareness

One hemisphere to other; S/S: lip smacking, confusion, patting, fear, staring, slow to answer, rubbing

Generalized seizures

• Involve both hemispheres

• Tonic-clonic: muscle contraction, LOC

Initial Alzheimer’s

Short-term memory loss (hallmark)

Moderate Alzheimers

• Global cognitive impairment

• Language

• Spatial relationships

• Problem solving

• Depression

• Confusion

• Disorientation

• Lack of insight

• Inability to carry on daily activities

Severe Alzheimer’s

• Loss of ability to respond to environment

• Requires total care

• Bedridden

Other types of dementia

• Vascular-dementia

• Hemorrhagic

• Vitamin B12 deficiency