Patho Exam 3

How does HIV infect a T- helper cell?

1. HIV, a retrovirus, carrying it's specific disease spreading genetic coding in RNA.
2. Its partner (surface glycoprotein - gp120) attaches to the CD4 receptor and is assisted by chemokine (a co-receptor that aids in the binding of gp120)
3. Viral RNA is

Sickle Cell disease happens when...

The cells sickle when the body is not well oxygenated and hydrated.

What happens once the RBC are sickled?

Once they are sickled you have occluded blood vessels, increased blood viscosity, further sickling of the cells, resulting in de-oxygenation of tissue and infarctions.

Sickled Cells characteristics

Abnormally shaped RBC and abnormal hemoglobin synthesis.

Thrombocytopenia

An autoimmune disease in with the immune system destroys platelets. Often caused by heparin, patient at high risk for blood loss

Concussion

mild injury to head, reversible with some swelling

Contusion

Worse than concussion, bruising of the brain causing increased ICP

Stroke

Strokes are 1) ruptures of cerebral artery or 2) occlusion of cerebral artery.

TIA

mini stroke - temporary, caused by platelet clumps. Sign of upcoming stroke. Blurred vision slurred speech, possible weakness numbness on one side and decreased level of consciousness.

What are the two types of strokes

hemorrhagic and occlusive strokes

Hemorrhagic

Blood vessel ruptures in the cranium have sudden onset, bleeding, necrosis, and scar tissue.

Occlusive strokes: 2 kinds

Cerebral thrombosis (most common type)
Cerebral Embolus

Cerebral Embolus

Sudden onset, clot breaks loose and travels to brain & occludes artery. Causing tissue death; side effects are depending on which area the occlusion occurs

Cerebral thrombosis

Most caused by atherosclerosis (plaque build up in artery wall) of cerebral artery causing occlusion.
Clot formation leading to brain necrosis, scar tissue remains
MOST COMMON TYPE OF STROKE

WHat are 3 vascular injuries of the brain ?

epidural hematoma, subdural hematoma, and Subarachnoid hemorrhage (SAH)

Subarachnoid hemorrhage

Bleeding into subarachnoid space arterial source, poor prognosis very hard to reach .

Epidural hematoma

strong blow to the head, medical emergency, bleeding in skull and dura. Blood accumulates in the epidural space causing pressure on the brain against the cranium on the opposite side of the bleed.

Subdural hematoma:

bleeding between dura and arachnoid mater, Venous bleed, symptoms of increased intracranial pressure. Types of Subdural include:
-Acute (symptoms 48 hours)
-Subacute (2 days - 2 weeks slower bleed)
-Chronic 2 weeks to several weeks (very slow bleed)

Manifestations of increased ICP

Intracranial pressure is caused by swelling of brain tissue, increased blood volume, and increased CSF(cerebral spinal fluid).
Manifestation:
-Early: confusion restless lethargic; Pupils subtlety react, sluggish
-Later: Loss of consciousness; Pupils are d

What's Cushing's Triad?

Cushing's Triad late signs that happen together to indicate ICP - Very high ICP, its hard to catch
1. Widening pulse pressure
2. bradycardia
3. Respirations - decreased and irregular

What is Herniation?

A severe increase of ICP, shifting of brain tissue from one compartment to another placing pressure on cerebral blood vessels and vital centers (Medula) results in death.

Patho for Guillian Barre

Possibly triggered by virus or bacterial infection often seen after GI, URI, Mono etc.
-inflammation, demyelination, axon destruction, and sensory/motor dysfunction

Manifestations of Guillian Barre

Inflammation of many nerves, mostly motor; Runs course starting at toes and moving up to head and 95% recover, function returns starting from head to toes

Patho of ALS

No inflammation, just degeneration, demylination and decrease number of neurons. Scarring and damages don't allow signals through

Manifestations of ALS

Sensory intact, weakness "clumsy" starts generalized, decreased motor function, no sensory changes, respiratory failure and death

Patho of MS

Demylination, inflammation scarring, interruption of impulses, molecular level-antigen presents to macrophage then presented to a na�ve T cell then crossed the BBB to CNS to set up autoimmune reaction.

Manifestations of MS

Muscle weakness, fatigue, spasticity, bladder dysfunction, blurred/double vision, parasthesias, dysphagia, and resp. difficulties.

Patho of Myasthenia Gravis

Decrease number of acetylcholine receptors, little or no muscle depolarization or contraction.

Manifestations of Myasthenia Gravis

Insidious, fatigue, flaccid, diplopia ptosis, dysphagia and later atelectasis

Patho of Alzheimer's

Senile plaques, neurofibrillary tangles, brain atrophy, decreased transmission of impulses R/T decreased acetylcholine

Manifestations of Alzheimer's

Physically intact but not mentally, progressive opposite of ALS. Decreased transmission, atrophy, plaques, and tangles.

Patho of Parkinson's

Idiopathic (cause unknown), arteriosclerotic (small stroke) drug influenced, R/T decreased dopamine to supress Acetylcholine, thus increased Acetylcholine activity

Manifestations of Parkinsons

Rigidity, akinesia (loss of movement), hypotonia (loss of tone) and tremor

Neurotransmitters in Alzheimers and Parkinsons

In Alzheimer's, the body doesn't produce enough acetylcholine and in Parkinsons it doesn't produce enough dopamine to suppress the action of acetylcholine.

Acetylcholine is to ___; as Dopamine is to _____.

Excitation; Suppression

Disorders that have demyelination

Guillian Barre, ALS, and MS have demyelinatation.

Which disorders can have remission and which are exacerbations?

Guillian Barre is the only remissionable disorder, alzheimer's, parkinson's, MS, and Myasthenia Gravis are all exacerbations. ALS is not either

Fetal development of the CNS

The central nervous system develops from the neural tube. At 20 days gestation, a neural groove appears in the ectoderm of the embryo. This groove deepens, the margins fuse together, and the tube forms in both directions from center of the embryo outward.

Neural Tube defects:

Anencephaly
Encephalocele
Spina Bifida and
Hydrocephalus

Anencephaly (think Amphibian)

soft bony part of skull and part of brain is missing; child has a frog like appearance from the front, death shortly after birth

Encephalocele

Herniation and protrusion of the brain and meninges through the skull. Usually in the occipital area. Very rare

Spina Bifida

Failure of the bony spine to close; 2 types occulta and cystica
2 types: spina bifida occulta or cystica.

SPINA BIFIDA OCCULTA

No visible defect; common in the lumbosacral area; may be in 10-30% of general population. May appear as a dimple, nevi, dark tufts of hair, or soft lipomas

SPINA BIFIDA CYSTICA

Visible sac-like protrusion, covered with skin or thin membrane:
� Meningocele--contains meninges and spinal fluid
� Myelomeningocele--contains the meninges, spinal fluid, and nerves

How a mother can help prevent spina bifida

Familial tendency has been reduced in families when the mother takes a B vitamin folic acid supplement before conception

Manifestations of spina bifida

Depending on location, may or may not involve sensory and motor impulses of bladder, rectum, lower extremities; may also have related joint deformities of hip, back, and feet, as well as possible visual-perceptual problems

Hydrocephalus

An increase in CSF volume, secondary to blockages or decreased absorption; this imbalance of secretion and absorption causes increased enlargement of the ventricles of the brain.
Two types include non-communicating/obstructive and communicating

Non-communicating/obstructive hydrocephalus:

There is obstruction to the flow of CSF through the ventricular system
� This obstruction can occur at any point causing dilatation of the structures and increased pressure proximal to the site.
� Most common sites:
� Aqueduct of Sylvius-post-hemorrhagic;

Communicating hydrocephalus:

� There is impaired absorption of the CSF by the arachnoid villa within the subarachnoid space

Symptoms of communicating hydrocephalus

Symptoms in infants: Bulging fontanels
� Abnormally large head (non-communicating tend to be larger) with prominent scalp veins,
� "Setting-sun" eyes-sclera visible above the pupil
� High pitched cry
� Irritability and lethargy
� Poor feeding with vomitin

Meningitis 2 types:

Bacterial and Viral or Aseptic

Bacterial meningitis

An acute infection of the meninges and CSF

Bacterial patho

� Organisms are spread to CSF by blood or by direct implantation (wounds, skull fractures, lumbar punctures, spina bifida)
� Organisms then invade the subarachnoid space and the inflammatory process takes place
� The brain becomes hyperemic and edematous

Bacterial manifestations

Clinical Manifestations:
� Infants
� Bulging fontanel
� Fever
� Poor feeding/vomiting
� Marked irritability
� Seizures accompanied by high-pitched cry
� Nuchal rigidity
� Positive Kernig and Brudzinski signs (positive Kernig is resistance or pain with ext

Cerebral Palsy

Is a group of nonprogressive disorders characterized by an early onset of impaired movement and posture. Characterized by abnormal muscle tone and coordination.
� Most common permanent physical disability of childhood.
� Motor and sensory deficits

Cerebral palsy is caused by...

� Prenatal: 44% of cases teratogens
� Genetic syndromes
� Chromosome abnormalities
� Brain malformations
� Intrauterine infections
� Placental problems
� Labor and Delivery: 19% of cases pre-eclampsia
� Complications of labor
� Perinatal: 8% Sepsis/CNS in

Cerebral Palsy patho

Hypoxia is the cause (from any of the above etiologies or other etiology).

3 types of cerebral palsy

Ataxic, Diskinetic, and Spastic

Spastic

(most common type, 65-75% of cases)
� Upper motor neuron weakness
� Increased muscle tone
� Exaggerated deep tendon reflexes
� Rigidity of the extremeties
3 types of spastic: Quadriplegic, hemiplegia, and diplegia.

Spastic cerebral palsy: Quadriplegic

Total body--highest incidence of severe disability
� Scissoring pattern of legs
� Exaggerated startle reflex
� Plantar flexion of feet

Spastic cerebral palsy: Hemiplegia

One side of body
� Extremities smaller on affected side
� Arm weakness and more spastic than legs
� Can usually walk, but may have gait disturbance
� Most frequent type of CP

Spastic cerebral palsy: Diplegia

Similar parts affected on both sides of the body
� Athetoid--abnormal involuntary movements
� Rotary twisting movements of trunk and extremities
� Facial grimacing, abnormal tongue movements, drooling
� Ataxic--impairment of balance and coordination
� Wid

Diskinetic cerebral palsy

(20-25% of cases)
� Difficulty with fine motor coordination and purposeful movements
� Jerky, abrupt, uncontrolled movements

Ataxic cerebral palsy

(approx 5% of cases)
� Gait disturbances and instability
� Stiffness of trunk muscles develops which affects gait and ability to maintain balance

Seizure disorders

Seizures are brief malfunctions of the brain's electrical system causing motor, sensory, autonomic or psychic manifestations and a change in the level of consciousness. Seizure activity may occur in anyone, given the right conditions.

Seizure disorders: Epilepsy

Epilepsy is the term for a chronic condition with recurrent and unprovoked seizures. 50-80% of those with epilepsy can have their seizures controlled with medication.

Seizure disorders: Epilepsy Etiology

� Tumors
� Infections
� Biochemical Disorders
� Trauma
� Toxins
� Fever (febrile seizures - vary according to child's individual threshold. Seen in 3-4% of all children, usually do not recur)
� Anoxia

Seizure disorders: epilepsy patho

Thought to be caused by spontaneous electrical discharge initiated by a group of hyperirritable cells called the epileptogenic focus. Normally these discharges are controlled within the focal area by normal inhibitory mechanisms. During some physiological

Seizure disorders: epilepsy classifications

Partial and Generalized

Partial

Involvement of one part of the brain; 2 types Simple and Complete

Seizure disorders: partial and complete epilepsy

Simple: involve one part of the body with movements
� May be motor or sensory (ringing, numbness, tingling)
� Does not lose consciousness
� May have psychic symptoms (feeling angry, frightened)
Complete: also called psychomotor
� Has loss of surroundings

Seizure disorders: Generalized epilepsy

Involves all of the brain; 6 types include:
- Absences (petit mal)
- Tonic/clonic (grand mal)
- Myoclonic
- Clonic
- Tonic
- Atonic

Absences: Petit Mal

� Non-convulsive with complete loss of consciousness for a short period of time
� Stop activity and then pick up where left off

Tonic/Clonic: Grand mal

� Generalized body seizure with loss of consciousness and seizure lasting 1 to 3 minutes

Myoclonic

� Single jerking of one or more muscle groups

Clonic

� Jerking of muscle groups--extension of arms and legs

Tonic

� Stiffening of muscle groups with flexion of arms and extension of legs

Atonic

� Lack of muscle tone -- "drop attacks

Phenylketonuria (not specifically on study guide)

Autosomal recessive disease: the enzyme is lacking which is needed to metabolize the essential amino acid phenylalanine to tyrosine; tyrosine is needed to form the pigment melanin, epinephrine and thyroxine
Clinical manifestations:
� Failure to thrive, ir

Interactional model in psychiatric disorders

Causes of Mental Illnesses/Interactional Model
� Environmental
� Behavioral
� Biological -- genetic, biochemical and anatomic
� Mental illness is multi-causal. The interaction of the three major factors can be described in an equation form:
Environmental

Neurotransmitters (which ones and how) involved in schizophrenia and mood disorders and addictions

SCHIZOPHRENIA
� Biochemical: There is a chemical excess of the neurotransmitter Dopamine. This causes the neurons to fire too rapidly.
MOOD DISORDERS
� Biochemical: There are two main neurotransmitters implicated in these problems. They are Serotonin and

Mania

Includes one or more manic episodes and usually one or more depressive episodes. Between the elevated and depressed mood episodes, individuals may experience long periods of a normal stable mood. This is usually cyclical.

Mania: Perceptual Disturbances

� perceives self as having special power or ability
� demanding and even overbearing
� may perceive time as moving too slowly
� may not perceive potentially dangerous or painful consequences of behavior
� may have hallucinations

Mania: Thought disturbances

� thinking is speeded up
� believe they are a great inventor, musician (delusions of grandeur)
� distractable - difficulty concentrating
� flight of ideas (abrupt changes from one topic to another)

Mania: Mood Disturbances

� euphoric
� good mood
� cheerful
� high
� irritable
� inflated self-esteem

Mania: Behavioral Disturbances

� loud rapid speech
� lacking sleep for several days
� excessive involvement in projects - writing a novel - or creating an invention
� spending money recklessly
� giving advice without knowledge

Depression

� Often called "common cold" of psychiatric illness
� More than 20 million Americans are affected at some time in their lives .

Depression: perceptual disturbances

� perceive others as negative toward self
� perceive little pleasure in life's activities
� perceive world as hopeless
� experience guilt and self-blame
� may have physical complaints that are usually false

Depression: thought disturbances

� difficulty concentrating
� memory disturbances
� difficulty making decisions
� delusions such as thinking one is responsible for some tragic event
� recurrent thoughts of death or suicide

Depression: mood disturbances

� feelings of worthlessness and guilt
� feelings of inadequacy
� negative self worth (low self-esteem)
� feeling sad, discouraged

Depression: behavioral disturbances

� sleep disturbances (sleeping too little or too much)
� agitation
� marked slowing of speech and body movements
� may attempt suicide
� lack of appetite or increase in appetite
� weight gain or weight loss