Pathology of The Nervous System Dr. Mohamed seyam phd.pt.

The Nervous Systemcontrols and coordinates all the functions of the body. it consists of two main sub-divisions:

1- Central Nervous System (CNS) 2- Peripheral Nervous System (PNS) The Peripheral Nervous System is

divided into two sub-divisions:

Somatic- voluntary Autonomic (ANS)- involuntary

Types of Brain Injury

Altered Consciousness and Unconsciousness

• Altered Consciousness Definition: condition of being less responsive to and aware of environmental stimuli.

• Unconsciousness Definition: physiological state in which the client is unresponsive to sensory stimuli and lacks awareness of self and the environment (Hickey, 2003)

Can be brief, lasting a few second to a few hours or longer.

To produce unconsciousness a disorder must:

1.Disrupt the RAS which extends up to the thalmus.

2.Significantly disrupt the function of both cerebral hemispheres

3.Metabolically depress overall brain function

Coma

Coma is a prolonged state of unconsciousness in which the client is unaware of self or the environment for sustained periods of time from hours to months. (Hickey, 2003)

Because of:

-disorders that affect BOTH cerebral hemispheres

- disorders that affect any part of the RAS

- direct compression on parts responsible for conciousness ie: hemorrhage, tumors

- metabolic disorders (hypoglycemia, hypoxia)

- toxins

** Duration of coma is associated with mortality & outcome****

Reduction in level of consciousness may be caused by extracranial or intracranial causes.

Types of Head Injury

Scalp injury: minor injury resulting in laceration,

abrasion & hematoma

Skull injury: may occur with or without damage

to brain.

Brain injury

Stroke

Occurs when there is not enough oxygen going to the brain.

AutismAutism is a developmental disorder that appears in the first 3 years of life, and affects the brain's normal development of social and communication skills.

Symptoms Most parents of autistic children suspect that something is wrong. Children with autism typically have difficulties in:

•Pretend play

•Social interactions

•Verbal and nonverbal communication People with autism may: •Be overly sensitive in sight, hearing, touch, smell, or taste

•Have unusual distress when routines are changed

•Perform repeated body movements

•Show unusual attachments to objects

Meningitiso Is an inflammation of

the membranes that surround the brain and spinal cord.

o Disease is caused by bacteria, or a virus.

o Symptoms – Very bad headache

Cerebral Palsy

Cerebral Palsy

Congenital disease

(born with)

Disturbance of motor functions

Herniated Disc

Disc in vertebra moves up against the spinal nerves. Very painful1. Anterior bulge2. Posterior bulge3. Posterolateral

bulge

Alzheimer’s diseaseIt is an irreversible, progressive brain disease that slowly destroys memory and thinking skills.

Risk factor Alzheimer’s disease (AD)1. Age 2. Apoe E4 Gene 3. Family History 4. Down Syndrome 5. Head Injury 6. Mild cognitive impairment(MCI) 7. Education Level 8. Gender

PATHOPHYSIOLOGY OF AD

The brains of people with AD have an abundance of two abnormal structures:

beta-amyloid plaques, which are dense deposits of protein and cellular material that accumulate outside and around nerve cells

neurofibrillary tangles, which are twisted fibers that build up inside the nerve cell

An actual AD tangle

An actual AD plaque

PARKINSON'S DISEASE

It is a Cellular degeneration of

dopamine-producing cells in the part of

the basal ganglia called the substantia

nigra, results in depletion of

neurotransmitter Dopamine. Imbalance

of dopamine and acetylcholine.

Manifestations

Tremor Rigidity Bradykesia Other key symptoms include: Flexed posture Loss of postural reflexes Freezing movements

Slowly progressive

regardless of treatment

"Shaky palsy" tremor/

rhythmic tremor (1st

symptom)

Usually idiopathic

150 per 100,000

After age 50

Characteristics

Multiple Sclerosis Chronic demyelinating disease that

affects the myelin sheath of neurons in

the CNS

Plaque develops on myelin causing inflammation, edema and eventual scarring. Clinical course is unpredictable combinations of sensory, motor, & coordinative dysfunctions followed by exacerbations followed by partial or complete remission.

Manifestations

Impaired mobility

Tremor

Pain

MS disease involvement in brain stem will result in (Charcot’s triad):

1. Nystagmus (constant involuntary movement of eye)

2. Disorder of Speech

3. Altered muscle Coordinate & gait tremor

Guillain-Barre Syndrome

An acute demyelinating disorder of the peripheral nervous

system characterized by progressive, usually rapid

weakness & paralysis.

One of the most common disorders of the Peripheral

Nervous System (PNS) : 1.7 per 100,000.

Cause unknown but believed to be an altered immune

response (approx. 2/3 of clients had a prior respiratory or GI

infection).

Four Clinical Presentations

Ascending

1. Most common, begins in legs and progresses upward

2. Symmetric motor deficits (paresis to tetraplegia)

3. Sensory deficits & diminished or absent reflexes

4. Respiratory insufficiency occurs in 50% cases

Stages of Guillain-Barre

1.Acute Stage: characterized by severe & rapid weakness; loss of

muscle strength progressing to tetraplegia & respiratory failure;

numbness, pain, facial muscle involvement.

2.Stabiulizing/Plateau Stage: 2-3 weeks after initial onset;

“leveling” off of symptoms

3.Recovery Stage: months to years with improvement of

symptoms.

Collaborative Care

Rapid diagnosis is important Medication only for support: antibiotics, morphine, anticoagulants. Surgery: tracheotomy may be necessary Plasmapheresis: removal of antibodies with concurrent administration of immunosuppressive agents Diet: TPN or nasogastric tube (NG) feeds may be necessary

Physiotherapy : prevent complications & limit effects of immobility (ROM, splints)