Chapter 6 Nervous Pathology

Chapter 6

Nervous System

Pathology

1

Diseases
and
Disorders
of the
Nervous
System

2

Common signs and symptoms

• Neuralgia, paresthesia
• Lack of coordination
• Muscle rigidity, spasms
• Seizures
• Tremors
• Recurrent headache
• Amnesia
• Difficulty speaking or finding the right

word

• Loss of sight, double vision
• Confusion, disorientation, loss of

consciousness

Neuro exam

• May include lumbar puncture (LP)

Groups of
Neurological
Diseases and
Disorders

3

Neurodegenerative

Functional

Infections

Structural disorders & Congenital

Injuries

Vascular

Amyotrophic Lateral Sclerosis (ALS)

4

Definition

• Progressive neurodegenerative disorder that

attacks motor neurons in the brain and
spinal cord

Etiology

• Unknown, but up to10% of cases have

genetic component

Signs and symptoms

• Initially mild, progressive muscle weakness,

typically starting in hands and feet,
eventually spreading to entire body

5

Alzheimer’s

Disease

(AD)

►

Definition

►Progressive neurodegenerative
brain disease characterized by
disorientation, memory failure,
speech disturbance, loss of
mental capacity

►

Etiology

►Combination of lifestyle, genetic,
and environmental factors

►Risk factors include age, herpes
simplex virus I

►

Signs and symptoms

►Gradual difficulty with recall of
recent activities, names; difficulty
reasoning, thinking, judging,
deciding, remembering,
performing familiar tasks;
personality and behavior changes

Huntington’s
Disease (HD)

6

• Progressive neurodegenerative

disorder

• Two types

• Early-onset
• Adult-onset

Definition

• Genetic defect

Etiology

• Initially, behavioral disturbances,

hallucinations, moodiness,
irritability, restlessness, psychosis,
and paranoia; facial grimacing, jerky
movements, slow and uncontrolled
movements, prancing gait;
dementia, memory, and speech
issues

Signs and symptoms

•Multiple
Sclerosis
(MS)
Signs and
symptoms

• Tingling,

numbness,
weakness in
extremities;
partial or
complete vision
loss or double
vision; slurred
speech;
fatigue; lack of
coordination

7

• Autoimmune neurodegenerative

disorder in which myelin sheath is
damaged, leading to slowed or
blocked messages to the brain

• Four types

• Clinically isolated syndrome (CIS)
• Relapsing-remitting MS (RRMS)
• Secondary progressive MS

(SPMS)

• Primary progressive MS (PPMS)

Definition

• Unknown, but risk factors include

family history of MS, Epstein-Barr
infection, thyroid disease, type 1
DM, IBS

Etiology

8

Parkinson’s Disease (PD)

► Definition

► Progressive neurodegenerative disorder in which

dopamine-producing neurons of the brain die off,
leading to symptoms

► Etiology

► Unknown; risk factors include genetics and

environment

Parkinson’s

Disease

(PD)

►
Signs and symptoms

► Tremors (especially

pill-rolling-type), bradykinesia,
shuffling gait, rigid muscles,
impaired balance and posture,
stooping, writing changes, loss
of automatic movements (e.g.,
blinking, smiling), facial
appearance of depression or
anger (masked face), speech
changes (e.g., slurring, soft
voice), loss of sense of smell,
trouble sleeping, dizziness,
constipation, excessive or
minimal sweating, drooling

9

10

Restless Legs Syndrome (RLS)

►
Definition

► Disorder in which abnormal sensation is experienced in the legs

when sitting or lying down, often comorbid with periodic limb
movement disorder

►
Etiology

► Unknown, but may be genetic if occurring before age 40. Risk

factors include peripheral neuropathy, iron deficiency, kidney
failure, spinal lesions, pregnancy, some medications. Often
worsened by caffeine, alcohol, and tobacco.

►

Signs and symptoms

► Abnormal sensations, such as itching, electric, aching, throbbing,

pulling, crawling, creeping, tingling, and burning, felt in legs and
feet after rest and that lessen with movement

Other
Neurodegene
rative
Disorders

11

Friedreich’s ataxia- damage to spinal
cord & nerves

Frontotemporal dementia- Pick
disease, abnormal protein in
damaged neurons

Lewy body disease- dementia

Tay-Sachs disease-progressive
destruction of neurons

Vascular dementia- mini strokes over
time

Cluster Headaches

12

Definition

A functional disorder in

which headaches occur in
cyclical patterns or clusters

Etiology

Unknown, but may be

related to increased release

of histamine or serotonin

Signs and symptoms

Sudden, severe, one-sided
headache with tearing eyes,
droopy eyelid, stuffy nose;
most commonly occurs 2-3
hours after falling asleep;

may be episodic

Tension
Headaches

13

• A functional disorder in which

headaches occur due to tense
scalp and neck muscles; the
most common type of headache

Definition

• Tense neck and scalp muscles,

possibly due to stress,
depression, anxiety, and/or head
injury

Etiology

• Dull, aching head; feelings of

tightness and pressure in
forehead to back of head

Signs and symptoms

Migraine

14

Definition

A functional disorder in
which headaches recur

Etiology

Stress, anxiety, hormone
changes, strong smells,
bright lights

Signs and
symptoms

Often, four stages

Prodrome (1-2 days before)

Aura (before or during)

Attack (lasting up to 72 hours)

Post-drome (up to 24 hours after)

Seizure Disorders

15

Definition

• Functional disorder in which

a sudden increase of
electrical activity in one or
more parts of the brain
occurs

• Classified based on origin

• Generalized onset
• Focal onset
• Unknown onset

Etiology

• Medications, high fevers,

head injuries, diseases,
illegal drugs

Seizure
Disorders

16

• Motor

• Jerking, twitching,

rigid/weak muscles,
spasms, automatic
movements, loss of
muscle tone

• Nonmotor

• Staring, heart palpitations,

goose bumps, stillness,
changes in emotions and
thinking

Signs and symptoms

Epilepsy

17

Definition

• Functional disorder that

causes recurring seizures

Etiology

• Genetics, brain injury,

abnormal development, illness;
but most often unknown

Signs and symptoms

• Vary according to type; can

include confusion, staring,
uncontrolled jerking, loss of
consciousness

Other Functional Disorders

►
Functional neurological disorder (FND)

►
Narcolepsy

►
Sciatica

►
Tourette syndrome (TS)

18

QUESTIONS?

19

Encephalitis

20

• Inflammation of the brain
• Several types, including

• Japanese encephalitis
• La Crosse encephalitis
• Saint Louis encephalitis

Definition

• Bacterial or viral infection

Etiology

• Flu-like symptoms in mild case;

severe headache, drowsiness,
confusion, seizures, sudden fever in
severe case

• Infants have body stiffness, bulging

fontanels, poor appetite, constant
cry

Signs and symptoms

Meningitis

► Definition

► Inflammation of the meninges

► Etiology

► can be a viral, bacterial, or fungal

infection; or noninfectious and
cancer-related forms

► Signs and symptoms

► Sudden high fever, severe headache,

stiff neck, nausea, vomiting; bacterial
can cause hearing loss, brain damage,
stroke

21

Shingles

► Definition

► A viral illness that causes a painful rash

► Etiology

► Varicella zoster virus

► Signs and symptoms

► Initially, tingling, pain, or itching on one

side of the face or body, then the
development of fluid-filled blisters; fever,
chills, headache, nausea, postherpetic
neuralgia, vision loss, encephalitis, facial
paralysis may also occur

22

Bell’s Palsy

► Definition

► Structural disorder in which the facial nerve

becomes swollen and inflamed, causing
facial paralysis

► Etiology

► Unknown; risk increases with pregnancy, DM,

viral URI

► Signs and symptoms

► Facial twitching, weakness, paralysis;

drooping eyelid, mouth corner; dry eyes or
excessive tearing; drooling or dry mouth;
decreased sense of taste

23

Guillain-BarréSyndrome

► Definition

► Rare structural autoimmune disorder in which

the immune system attacks the PNS

► Etiology

► Unknown; may be triggered by surgery,

infection, vaccination

► Signs and symptoms

► Weakness and tingling starting in legs and

spreading, causing near-paralysis; can be
life-threatening

24

Trigeminal Neuralgia

► Definition

► Structural disorder in which a blood vessel or

tumor presses on the trigeminal nerve, causing
chronic pain

► Etiology

► Pressure on trigeminal nerve

► Signs and symptoms

► Vary; sudden, severe, stabbing pain to

constant, aching, burning pain; can be
widespread or focal; often episodic, with
worsening subsequent pain

25

Other Structural Disorders

► Astrocytoma- malignant tumor made of

astrocytes

► Medulloblastoma- tumor made of medullablasts

► Meningioma-malignant tumor of meninges

► Neuroblastoma- malignant tumor of sympathetic

nervous system

► WHAT IS THE COMMON SUFFIX?

26

Traumatic Brain Injury (TBI)

► Definition

► An acquired brain injury

► Concussion

► Contusion

► Etiology

► Injury as a result of falls, MVAs, violence,

sports, military service, etc.

27

Traumatic Brain Injury (TBI)

(2 of 3)► Mild

► Headache, neck pain, nausea, ringing in

the ear, dizziness, lightheadedness, blurred
vision, tiredness, dazed feeling, mood
changes, trouble concentrating or
remembering. Children experience
irritability and changes in eating.

► Moderate or severe

► Similar to mild, but headache is constant

and worsens; repeated vomiting, seizures,
inability to awaken, dilated pupil(s), slurred
speech, agitation, loss of coordination,
extremity weakness. Children become
inconsolable and refuse to eat.

28

Spinal Cord Injury

►
Definition

►Dislocation of vertebrae in which the bone cuts into or presses
on the nerves

►Types

► Complete

► Incomplete

►
Etiology

► Common causes are MVAs, falls, violence,

diseases, sports injuries

► Risk increases with use of alcohol

29

Spinal Cord Injury

► Signs and symptoms

► Initially, extreme back or neck pain,

incontinence, difficulty breathing,
paralysis

► Quadriplegia

► Affects arms, hands, trunk, legs,

pelvic organs

► Paraplegia

► Affects some or all of the trunk, legs,

pelvic organs

30

Peripheral Neuropathy

(1 of 2)

►
Definition

►A disorder in which damage to the PNS causes varied
symptoms; over 100 types

►
Etiology

►Inherited, unknown

►Acquired

► Physical injury, diseases, toxin exposure

►
Signs and symptoms

►Tingling, numbness, paresthesia, weakness, increased
sensitivity to stimuli, burning pain, muscle wasting, paralysis,
organ dysfunction

31

Fetal Alcohol Spectrum
Disorders

►
Signs and symptoms

►Dependent on trimester of consumption, amount consumed

►Include poor memory, hyperactivity, attention and math
difficulty, speech and language delays, learning and
intellectual disabilities, poor reasoning and judgment, vision
and/or hearing problems, heart, kidney, and/or bone
problems, poor coordination, small head, short stature,
abnormal facial features

►In babies

► Low birth weight, sleeping and sucking problems

32

Spina Bifida

► Definition

► Neural tube defect in which the spinal

column doesn’t close during fetal
development

► Etiology

► Unknown

► Signs and symptoms

► Spina bifida occulta or

Closed neural tube defect

33

Other
Congenital
Disorders

34

Cerebral palsy (CP)

• Group of nonprogressive disorders caused

by abnormal brain development or injury

• Classified by main type of movement

disorder
• Spasticity (stiff muscles)
• Dyskinesia (uncontrolled movements)
• Ataxia (discoordinated gait)

Down syndrome

Tuberculosis sclerosis- syndrome of
benign tumors in major organs

Cerebro-
vascular
Accident
CVA

35

Definition

• Condition in which a blood vessel in the

brain is either blocked or ruptures

Etiology

• Ischemic

• Arterial blood flow to part of brain is

blocked
• Thrombotic
• Embolic

• Hemorrhagic

• Brain artery leaks or ruptures

• Intracerebral
• Subarachnoid

• Transient ischemic

• Brief disruption of blood to part of the

brain

Cerebrovascular
Accident

►
Signs and symptoms

►Related to part of brain affected

►Confusion or mental changes; speech difficulty; unilateral
facial, arm, or leg numbness; visual disturbances; movement
and coordination difficulties; arm weakness; sudden, severe
headache; facial drooping; hemiparesis or hemiplegia

►
F-A-S-T

►
Face drooping

►
Arm weakness

►
Speech difficulty

►
Time call 9-1-1

36

Hematoma

► Definition

► Blood leakage into the brain

► Common types

►Epidural

►Subdural

►Intraparenchymal

► Etiology

► Head trauma (most common), leaking aneurysm,

HTN, tumor

► Signs and symptoms

► Epidural: confusion, dizziness, altered level of

alertness/drowsiness; enlarged pupil; severe
headache; loss of consciousness, then alertness,
then deterioration of alertness; nausea and
vomiting; weakness in part of the body

37

Life Span Changes

►
Infants

►Immature nervous system

►
First years of life

►Increased brain size

►
Childhood

►Learning and thinking increase in complexity

►
Adulthood

►Stable brain functioning

►
Aging

►Loss of brain and spinal cord cells, accumulation of waste
products, decreased brain functioning

38

Questions?

39