Selected Neurological and - PowerPoint Presentation

Slide1

Selected Neurological and

Respiratory Disorders

Slide2

Neurological Disorders

Muscle Paralysis

Neural Tube Disorders

Cerebrovascular Accidents (Stroke)

Transient Ischemia Attack

Aneurysm

Slide3

Muscle Paralysis

Flaccid paralysis

Destruction of motor neurons by disease

Interruption of reflex arc responsible for muscle tone

Muscle deprived of innervation

Low muscle tone

Peripheral nerve destruction

Spastic paralysis

Reflex arc not disturbed

Injury to cortical neurons stops voluntary control

Muscle retains innervation

Increased muscle tone

Slide4

Neural Tube Defects

Anencephaly

Failure of normal development of brain and cranial cavity

Multifactorial inheritance

Spina bifida

Diagnosis: amniocentesis and alpha-fetoprotein levels

Alpha-fetoprotein leaks from fetal blood into amnionic fluid through open neural tube defect; high levels found in amnionic fluid

Occult

Meningocele

Meningomyelocele

Slide5

Characteristic appearance of anencephalic infant

Slide6

Various types of spina bifida.

Slide7

Neural Tube DefectsA. Thoracic meningomyelocele covered by thin membraneB. Large meningomyelocele associated with neurologic deficit

Slide8

Stroke: Cerebrovascular Accident (1 of 5)

Any injury to brain tissue from disturbance of blood supply to brain

Types of stroke

Cerebral thrombosis: most common; thrombosis of cerebral artery narrowed by arteriosclerosis

Cerebral embolus: occurs less frequently; blockage of cerebral artery by fragment of blood clot from an arteriosclerotic plaque or from heart

Cerebral hemorrhage: most serious type of stroke; usually from rupture of a cerebral artery in person with hypertension

Slide9

Stroke: Cerebrovascular Accident (2 of 5)

Predisposing Factors

1. Mural thrombus formed on wall of left ventricle adjacent to a healing myocardial infarction

2. Thrombus formed on rough surface of diseased mitral or aortic valve

3. Small thrombus in left atrium of person with atrial fibrillation

Slide10

Stroke: Cerebrovascular Accident (3 of 5)

Ischemic infarct: no blood leaks into brain

Hemorrhagic infarct: blood leaks into damaged brain tissue

Arteriosclerosis of extracranial arteries

Sclerosis of a major artery from aorta that supply brain

Common affected site: carotid artery in neck; arteriosclerotic plaque may narrow lumen and reduce cerebral blood flow

Slide11

Stroke: Cerebrovascular Accident (4 of 5)

Diagnosis

Cerebral angiogram

Carotid endarterectomy

Less invasive methods: similar to balloon angioplasty and stent insertion procedures used to treat coronary artery plaques

Slide12

Stroke: Cerebrovascular Accident (5 of 5)

CT scan: can distinguish a cerebral infarct from cerebral hemorrhage

Magnetic resonance imaging (MRI): provides similar information and is equally effective

Slide13

Effects of atherosclerosis of carotid artery

A. Narrowing of lumen

B. Thrombus formation

C. Thrombus dislodged & forms emboli

D. Complete occlusion of artery by thrombus

Slide14

Coronal section of brain illustrating large cerebral hemorrhage that has compressed and displaced the cerebral ventricles.

Slide15

Transient Ischemic Attack, TIA

Brief episodes of neurologic disfunction

From embolization of material from plaque in carotid artery

One-third of patients eventually suffer major stroke

Treatment: endarterectomy or medical therapy

Slide16

Cerebral Aneurysm

Congenital aneurysm of circle of Willis

Congenital weakness in arterial wall allows lining to protrude

Weakness is congenital but aneurysm develops in adult life

Rupture causes subarachnoid hemorrhage

Hypertension predisposes

Treatment: aneurysm occluded surgically

Arteriosclerotic aneurysm

Cerebral artery dilates and compresses adjacent tissue

Rupture uncommon

Slide17

Dissection of vessels from the brain of a person with large congenital cerebral aneurysm.

Slide18

A cerebral aneurysm (arrow) demonstrated by an angiogram.

Slide19

Undersurface of brain, illustrating subarachnoid hemorrhage secondary to ruptured cerebral aneurysm.

Slide20

Respiratory Disorders

Pneumothorax

Atelectasis

Pneumonia

Tuberculosis

Bronchitis

Chronic Obstructive Pulmonary Disease (COPD)

Emphysema

Bronchial Asthma

Slide21

Pneumothorax Pathogenesis/Manifestations

Pathogenesis

Lung injury or pulmonary disease that allows air to escape into the pleural space

Stab wound or penetrating injury to the chest wall

Spontaneous

– generally in young healthy persons

Manifestations

Chest pain

Shortness of breath

Air in pleural cavity

Tension

pneumothorax

Slide22

Tension Pneumothorax

Development of a higher than atmospheric pressure in the pleural cavity – creating a tension

Can accompany any type of pneumothorax

Upon inhalation air enters pleural space – due to drop in intrapleural pressure

On exhalation – air gets trapped due to the edges of the tear compressing as a result of the increased intrapleural pressure – thus the pressure in the intrapleural space is getting greater and greater

Heart and Mediastinal structures shifted away from pneumothorax

Slide23

Atelectasis

An incomplete expansion of the lung, a

collapse

of a part of the lung

There are two types

1.

Obstructive

atelectasis:

complete

bronchial obstruction by

Mucous secretions, tumor, foreign object

Resulting in collapse of the part of the lung supplied by the blocked bronchus

Can also develop as a postoperative complication, where because of the pain, the patient does not cough or breathe deeply, accumulating mucous secretions

Slide24

Atelectasis

2.

Compression

atelectasis

External

compression on the lung

Fluid, air, or blood in the pleural cavity, reducing its volume and preventing lung expansion

Slide25

Pneumonia

An

inflammation

of the lung

The

exudate spreads

unimpeded through the lung

Filling the

alveoli

The affected portions of the lung become relatively solid (

consolidation

)

At times, the exudate

reaches

the

pleural surface

Slide26

Pneumonia Classification

Classification

Etiology: most important because it serves as a

guide for treatment

Bacteria,

chlamydia, mycoplasmas, rickettsiae, viruses

, fungi

Anatomic distribution of the inflammatory process- describes

what part of the lung

is involved

Lobar:

entire

lung (bacteria, neutrophil infiltration)

Bronchopneumonia (bacteria, neutrophil infiltration):

parts

of one or more lobes adjacent to the

bronchi – bronchopulmonary segments

Slide27

Pneumonia Classification

Interstitial pneumonia or primary atypical pneumonia (virus or mycoplasma; lymphocyte, monocyte, and plasma cell infiltration): alveolar septa affected

Predisposing factors

that lead to its development

Any condition associated with

poor lung ventilation and retention of bronchial secretions

Postoperative – atelectasis and secondary bacterial infection

Aspiration

Obstruction

Slide28

Clinical features of pneumonia

Manifestations of systemic infection

Feeling ill

Elevated temperature

Increased white blood cell count

Manifestations of lung inflammation

Cough

Purulent sputum

Pain on respiration if involves pleura

Shortness of breath

Slide29

Tuberculosis

It is a

special type

of

pneumonia

caused by

Mycobacterium

tuberculosis – an acid – fast bacteria

Because

the tubercle bacillus has a capsule composed of waxes and fatty substances, it is

more resistant to destruction

than

others – thick cell wall

As a result of this organism’s resistance – monocytes accumulate around the bacteria – many fuse with the bacteria attempting phagocytosis – but the fusion produces a large multinucleated “giant cell”. Lymphocytes and plasma cells surround the area – followed by fibrous tissue proliferation. The central portion becomes necrotic – thus a

granuloma

is formed. TB is termed a

granulomatous disease.

Slide30

Manifestations

Course of infection

Acquired from organisms inhaled in airborne droplets

Organisms lodge within pulmonary

alveoli where they proceed to multiply

Initially the organisms do not elicit a marked inflammatory reaction because they do not produce any toxins or destructive enzymes

Macrophage phagocytose the bacteria but are unable to destroy them – they may even carry the organisms to other parts of the lung and into regional lymph nodes.

After several weeks cell-mediated

immunity develops

Sensitized T- cytotoxic lymphocytes attract and activate macrophages – the activated

macrophages attack and destroy many of the

organisms forming the characteristic

granulomas formed

In the majority of cases the person is unaware they have been infected – no symptoms

Infection

arrested in majority of cases

Outcome depends

Number of organisms inhaled

State of body’s defenses

May heal by scarring or progress to cavitation

Slide31

Sometimes the granuloma is large enough to be seen on X-ray but most of the times it is too small

The positive skin test reveals the infection

Cell-mediated immunity

generally

controls the infection

The healed granuloma may contain small numbers of viable organisms and the infection may become reactivated when the immune system drops

In some individuals the primary infection does not respond favorably to the immune system fight

The granuloma may extend into a nearby bronchus and necrotic inflammatory tissue is discharged into it

A cavity may form

If the person gets reactivation of the bacteria (becomes active) and they have cavitation (into bronchus) their sputum can be infectious to others

Slide32

Most cases of active TB do not result from the initial infection – but rather by a reactivation – however some are due to a reinfection (new case)

How does reactivation occur- it is due to a drop in the immune system action as a result of AIDS, other debilitating diseases, treatment with corticosteroids, treatment with immunosuppressive therapy

Slide33

Extrapulmonary tuberculosis

Result of hematogenous spread of tubercle bacilli – thus a secondary infection

Sites

Kidneys

Bone

Uterus

Fallopian tubes

Sometimes the secondary infection may progress even though the pulmonary infection has healed leading to an active extrapulmonary TB without clinically apparent pulmonary TB

Slide34

Tuberculosis

Diagnosis

Skin test (

Mantoux

): a positive test reveals

recent

infection

chest x-ray: when the

granuloma

is large enough to be

detected – or see pulmonary infiltrates

sputum

culture – acid fast bacteria

Slide35

The tuberculosis skin test (also known as the tuberculin test or PPD test) is a test used to determine if someone has developed an immune response to the bacterium that causes tuberculosis (TB). This response can occur if someone currently has TB, if they were exposed to it in the past, or if they received the BCG vaccine against TB (which is not performed in the U.S.).

The tuberculin skin test is based on the fact that infection with

M. tuberculosis

produces a delayed-type hypersensitivity skin reaction to certain components of the bacterium.

Slide36

Tuberculosis

Treatment

Cell-mediated immunity

generally controls the infection

The

healed

granulomas,

however, may contain small numbers of

viable organisms

, and the

infection

may become

reactivated

Not all primary infections respond as favorably

If a

large number

of organisms are inhaled or if the

host is compromised

(body’s defenses are inadequate), the inflammation will progress, causing more destruction of lung tissue

Slide37

Tuberculosis

People who have

active progressive

tuberculosis with a

tuberculous cavity

can

infect others

because they can discharge large numbers of tubercle bacilli in the sputum

Treatment

Antibiotics

and Chemotherapeutic agents

Drug-resistant tuberculosis treatment

More prolonged

Results less satisfactory

Drugs recommended

Following conversion of a negative into positive skin test reaction

Patients with inactive tuberculosis who have increased risk

 

Slide38

Bronchitis

An

inflammation

of the tracheobronchial mucosa

Acute

bronchitis

Common and self-limiting

Chronic

bronchitis – often associated with emphysema in COPD

Secondary to chronic irritation by smoking or atmospheric pollution

Slide39

Bronchiectasis

Walls weakened by inflammation and dilate

Distended bronchi retain secretions

Chronic cough

Production of large amounts of purulent sputum

Diagnosed with bronchogram

A specialized X-ray which consists of taking films after instilling a radiopaque oil into the trachea and bronchi.

The oil covers the mucosa of the bronchi, and the abnormal bronchi can be recognized as dilated

Only

effective treatment is surgical resection of affected segments of lung

Slide40

Upper Respiratory System

– From nose and mouth down to Lungs – (includes nose, mouth, pharynx, larynx, and trachea

Lower Respiratory System

– Mainstem bronchus to Alveoli

Upper Airway

– From nose and mouth to and inclusive of larynx (voice box)

Lower Airway

– Trachea down to alveoli

Slide41

Chronic Obstructive Pulmonary Disease

Emphysema

and

chronic bronchitis

occur together so frequently that they are usually considered a

single entity

, designated

COPD

Emphysema is

characterized by loss of elasticity (increased pulmonary compliance) of the lung tissue caused by destruction of structures feeding the alveoli

Chronic

bronchitis –

Secondary to chronic irritation by smoking or atmospheric pollution

Clinical

manifestations

Dyspnea

Cyanosis

Slide42

Emphysema

•

The

air spaces

distal to the terminal bronchioles are

enlarged

and their

walls

are

destroyed

•

The normally

fine alveolar structure of the lung

is

destroyed

•

The

large cystic air spaces form throughout

the lung

•

The destructive process usually

begins

in the

upper lobes

but eventually may affect all lobes

•

Once

emphysema

has

developed

, the damaged lungs

cannot

be restored to

normal

Slide43

Bronchial Asthma

Spasmodic contraction

of smooth muscles in the walls of the

smaller bronchi and bronchioles

It causes

shortness of breath

and

wheezing

respiration

Exerts a

greater effect

on

expiration

than on inspiration

Attacks are

precipitated by

allergens

: inhalation of dust, pollens, animal dander, or other allergens

Treated with drugs such as

epinephrine or theophylline

that relax bronchospasms and block the release of mediators from mast cells

Slide44

Bronchial Asthma

Pathogenesis

Spasmodic contraction of smooth muscles in walls of smaller bronchi and bronchioles

Associated with increased secretions from bronchial mucous glands

Clinical manifestations

Shortness of breath

Wheezing respirations

Air flow impeded more on expiration than on inspiration

Air trapped in lungs

Lungs become overinflated

Slide45

Attacks precipitated by allergens

Interact with mast cells coated with IgE antibody

Release chemical mediators that induce bronchospasm

Treatment

Drugs that relax bronchospasm

Epinephrine

Theophylline

Drugs that block release of mediators from mast cells