The Nervous System

Medical Terminology to Know

AnoxiaAphasia AtaxiaAuraDyskinesiaDysphagia EmbolusEncephalopathyGaitHemiparesis

Intracranial pressure IschemiaNeuralgiaOcclusionParesthesiaParaplegia QuadraplegiaSeizureSundowner’s syndromeSyncope

What is it? A highly complex organized system that

coordinates all of the activities of the body.

This system enables the body to respond or adapt to changes that occur both inside and outside the body.

Components of the Nervous System

Brain Spinal Cord Nerves

Nerves

Parts of the Nervous System

The nervous system is broken down into 2 major parts. Central Nervous System Peripheral Nervous System

Central Nervous System

Consists of: Brain Spinal Cord

The Brain

The Brain The brain is a mass of nerve tissue well

protected by membranes and the cranium.

It is made up of several sections. Cerebrum Cerebellum Diencephalon Midbrain Pons Medulla oblongata

Sections of the Brain

Cerebrum The largest and highest section of the

brain. The outer part is arranged in folds,

called convolutions, and separated in lobes.

The lobes include: Frontal Parietal Occipital Temporal

Cerebrum

Frontal Lobe

Parietal Lobe

OccipitalLobe

TemporalLobe

Functions of the Cerebrum

Reasoning Thought Memory Speech Sensation Sight Smell Hearing Voluntary body movement

Cerebellum The section below

the back of the cerebrum.

Cerebellum

Functions of the Cerebellum

Muscle coordination Balance Posture Muscle tone

Diencephalon The structure that lies between the

cerebrum and the midbrain. It contains two structures:

Thalmus- acts as a relay center and directs sensory impulses to the cerebrum.

Hypothalmus-regulates and controls the autonomic nervous system, temperature, appetite, water balance, sleep, blood vessel constriction and dilation. It is also involved in emotions such as anger, fear, pleasure, pain, and affection.

Diencephalon

Midbrain

The section located below the cerebrum at the top of the brainstem.

Functions: conducting impulses between brain parts certain eye movements auditory reflexes

Midbrain

Pons The section located below the midbrain

and in the brain stem. Functions:

Conducting messages to other parts of the brain

Certain reflex actions including chewing, tasting, and saliva production

Assists with respiration

Pons

Medulla Oblongata

The lowest part of the brain stem. It connects with the spinal cord. Functions: Regulation of

Heartbeat Respiration Swallowing Coughing Blood pressure

Medulla Oblongata

Spinal Cord Continues down from the medulla

oblongata and ends at the first or second lumbar vertebrae.

It is surrounded and protected by vertebrae.

Spinal Cord

Functions of the Spinal Cord

Responsible for many reflex actions and for carrying messages to and from the brain to the nerves that go to the organs and glands.

Peripheral Nervous System

Consists of the nerves. Broken down into 2 parts:

Autonomic nervous system Somatic nervous system

Autonomic Nervous System

Helps maintain balance in the involuntary functions of the body.

Allows the body to react in times of emergency.

There are 2 divisions of the ANS Sympathetic nervous system Parasympathetic nervous system

Sympathetic/Parasympathetic

Usually work together to maintain homeostasis in the body.

Control involuntary body functions. Sympathetic NS- In times of emergency,

prepares body for “fight or flight” Increases heart rate, respirations, BP, and

slows digestion Parasympathetic NS- After the

emergency, counteracts the actions of the Sympathetic NS. Decreases heart rate, respirations, BP, and

speeds up digestion

Somatic Nervous System

Made up of 12 pairs of cranial nerves and 31 pairs of spinal nerves and their branches.

Some of the cranial nerves are responsible for the special senses such as sight, hearing, taste, and smell

Others receive general sensations such as touch, pressure, pain, and temperature.

Brain Hemispheres

Your brain is divided into left and right hemispheres.

The right side of your brain controls the left side of your body.

The left side of your brain controls the right side of your body.

Left Brain/Right Brain

Diseases and Disorders Alzheimer’s Disease /

Dementia Amyotrophic lateral

sclerosis Aneurysm Brain neoplasm Cerebral Palsy Cerebrovascular

Accident (CVA) / Transient Ischemic Attack

Enchephalitis

Epilepsy / Seizure Disorder

Hydrocephalus Meningitis Multiple Sclerosis Parkinson’s Disease Shingles Spina Bifida Tourette Syndrome

Alzheimer’s Disease / Dementia

Dementia is a degenerative syndrome characterized by deficits in memory, language and mood.

The most common form of Dementia is Alzheimer’s disease which develops gradually and usually over the age of 60.

Causes: neuron degeneration and plaque formation causing communication interrupt.

Alterations in acetylcholine, norepinephrine, GABA and serotonin.

Alzheimer’s Disease / Dementia

Early symptoms include loss of short term memory and sundowner’s syndrome.

Advanced symptoms include psychosis, aggression, and profound personality changes.

End stage symptoms include loss of judgment, inability to perform personal care and physical illnesses that lead to death.

Alzheimer’s Disease / Dementia

Diagnosis: The only definitive diagnosis is through brain autopsy. While alive, it is diagnosed through symptoms, physical exam, neuropsychological tests and lab tests.

Treatment: Medications to slow progression of memory loss and confusion such as Aricept, Exelon, Razadyne, Cognex and Namenda.

Antidepressants, Anxiolytics, Antipsychotics for other symptoms.

Amyotrophic Lateral Sclerosis (Lou Gehrig’s

Disease) Disease of the nerve cells in the brain

and spinal cord that control voluntary muscle movement.

Neurons waste away or die and can no longer send messages to muscles.

Leads to muscle weakening, twitching and inability to move.

Causes: Genetic defect or unknown

Amyotrophic Lateral Sclerosis (Lou Gehrig’s

Disease) Diagnosis: Blood tests to rule out other

conditions, breathing tests to assess lung function, CT or MRI to rule out injury, Electromyography, Genetic testing, nerve conduction studies, spinal tap or lumbar puncture.

Amyotrophic Lateral Sclerosis (Lou Gehrig’s

Disease) Symptoms: The senses are not

affected. As the disease progresses, there is loss of muscle strength and coordination.

Difficulty breathing, swallowing, head drop, muscle cramps, muscle contractions, paralysis.

There is no Cure. Riluzole slows progression.

Aneurysm Brain aneurysm is a bulging, weak area

in the wall of a brain artery. When it ruptures it is called a subarachnoid hemorrhage. Depending on severity, death may occur.

Most common location is in the base of the brain in the Circle of Willis.

Causes / Risks: Aging, atherosclerosis, family history, hypertension, smoking, previous aneurysm.

Aneurysm Diagnosis: Brain CT scan, lumbar

puncture, MRI/MRA (magnetic resonance imaging/angiography), cerebral angiogram

Symptoms: sudden, severe headache, neck pain, nausea, vomiting, sensitivity to light, fainting, loss of consciousness, seizures

Treatment: Coil embolization, surgical clipping.

Brain Neoplasm May originate from neural elements

within the brain or may be metastasis from other cancers in the body. Tumors invade, infiltrate and disrupt normal function of the parenchymal tissue. Leads to increased intracranial pressure and the flow of cerebrospinal fluid.

Diagnosis: lab studies, CT imaging, MRI imaging

Brain Neoplasm Symptoms: Headache, mental status

changes, memory loss, emotional changes, behavioral disturbances, sensory disturbances, seizures, hemiparesis, speech difficulties,

Treatment: surgery, radiation, limited chemotherapy,

Cerebral Palsy A disturbance in voluntary muscle

action. There is no cure. Caused by brain damage

Lack of oxygen to the brain Birth injuries Prenatal rubella (German measles) Infections

Cerebral Palsy 3 Types (Spastic, athetoid, ataxic) Spastic is the most common type. Symptoms

Exaggerated reflexes Tense muscles Contracture development Seizures Speech impairment Spasms Tremors In some cases mental retardation

Cerebral Palsy Treatment

Physical and occupational therapy Speech therapy Muscle relaxants Anticonvulsants Casts Braces Orthopedic surgery for severe

contractures

Cerebrovascular Accident (CVA) / Transient Ischemic

Attack Transient Ischemic Attack (TIA) – blood flow

to part of the brain stops for temporarily (ischemia). The patient has stroke like symptoms for a few hours. May be a warning sign of an impending CVA (stroke)

Cerebrovascular Accident – Blood flow to the brain is stopped (infarction), causing permanent damage.

Cerebrovascular Accident (CVA)

Lack of blood flow to the brain results in lack of oxygen and a destruction of brain tissue at the cellular level.

Causes: Cerebral hemorrhage (from hypertension) Aneurysm (weak blood vessel) Occlusion/blockage (atherosclerosis) Thrombus (blood clot)

Cerebrovascular Accident (CVA)

Signs and Symptoms vary depending on the area and amount of brain tissue damaged but can include: Loss of consciousness Weakness or paralysis on one side of the body

(hemiplegia) Dizziness Dysphagia (difficulty swallowing) Visual disturbances Mental confusion Aphasia (speech or language impairment) Incontinence (loss of bowel or bladder control)

Cerebrovascular Accident (CVA)

Treatment The first 3 hours of a CVA are critical. Treatment with a thrombolytic agent (clot-

busting drugs) can dissolve a clot and restore blood flow to the brain.

CT scans can determine the area of the brain involved.

Additional treatment depends on symptoms and is directed toward helping the patient recover from or adapt to the symptoms that are present.

Encephalitis An inflammation of the brain caused by a

virus, bacteria, or chemical agent. The virus is frequently contracted by a

mosquito bite. Symptoms vary but can include: fever,

extreme weakness, lethargy, visual disturbances, headache, vomiting, stiff neck and back, disorientation, seizures and coma.

Treatment: antiviral drugs, maintenance of fluid and electrolyte balance, antiseizure meds, monitoring of kidney and respiratory function.

Epilepsy / Seizure Disorder

A brain disorder associated with abnormal electrical impulses in the neurons of the brain.

Causes can include: Brain injury Birth trauma Tumors Toxins (lead poisoning etc.) Infections

Epilepsy Absence or Petit mal seizures are

milder and characterized by a loss of consciousness lasting several seconds.

Tonic-clonic or grand-mal seizures are the most severe. They are characterized by loss of consciousness lasting several minutes, convulsions accompanied by violent shaking and thrashing movements, hypersalivating (causing foaming at the mouth) and loss of body functions.

Treatment : Anticonvulsant Drugs

Hydrocephalus An excessive accumulation of cerebrospinal

fluid (CSF) in the brain. Causes:

congenital (at birth) defect Infection Tumor that obstructs the flow of CSF

Symptoms: Abnormally enlarged head Prominent forehead Bulging eyes Irritability Distended scalp veins Retardation (when pressure prevents proper

development)

Hydrocephalus Diagnosis: neuro eval, ultrasound, CT,

MRI. Treatment includes surgically

implanting a shunt (tube) into the brain to allow for drainage of the excessive fluid.

Meningitis An inflammation of the meninges of the

brain and/or spinal cord. Can be caused by a virus, bacteria,

fungus, or toxins such as lead or arsenic. Lumbar puncture to determine cause.

Symptoms: high fever, headache, neck and back pain, stiffness, nausea, vomiting (N/V), delirium, convulsions, and if untreated coma and death.

Treatment: antibiotics, anticonvulsants, pain meds, and meds to treat cerebral edema.

Multiple Sclerosis (MS)

A chronic progressive disabling condition resulting from a degeneration of the myelin sheath in the central nervous system.

Usually occurs between the ages of 20 and 40.

The cause is unknown.

Multiple Sclerosis (MS) The disease progresses at different rates and

has periods of remission. Early symptoms include: visual

disturbances, weakness, fatigue, poor coordination, and tingling and numbness.

As the disease progresses: tremors, muscle spasticity, paralysis, speech impairment, emotional swings, and incontinence.

Treatment: physical therapy, muscle relaxants, steroids, psychological counseling are all used to maintain functioning ability as long as possible.

Parkinson’s Disease A chronic progressive condition involving

degeneration of brain cells. Usually occurs in persons over 50 years old. Symptoms: tremors, stiffness, muscular

rigidity, a forward leaning position, shuffling gait, loss of facial expression, drooling, mood swings, frequent depression, behavioral changes.

There is NO cure. Treatment: Levodopa (medication to relieve

symptoms), physical therapy to limit muscle rigidity.

Shingles Also called Herpes zoster An acute inflammation of nerve cells and is

caused by the herpes virus , which also causes chicken pox.

It commonly shows on the thoracic area on one side of the body and follows the path of affected nerves.

Symptoms: fluid filled vesicles appear on the skin, severe pain, redness, itching, fever, and abnormal skin sensations.

Treatment: directed toward relieving pain and itching until the inflammation subsides, usually in 1-4 weeks.

Spina Bifida Myelomeningocele A birth defect in which the backbone

and spinal canal do not close before birth.

Cause is unknown, low folic acid during pregnancy may play a part in this defect.

Diagnosed with prenatal screening. Also may have a blood test called a quadruple screen. There are higher levels of maternal alpha fetoprotein.

Spina Bifida Symptoms: newborn may have a sac

protruding from mid to lower back, dimpling or hair in the same area.

Loss of bladder/bowel control Partial or complete lack of sensation /

paralysis or weakness Club foot, hydrocephalus Treatment: Surgery, treat symptoms.

Tourette’s Syndrome Neuro disorder characterized by

repetitive, stereotyped, involuntary movements and vocalizations called tics.

Cause is unknown, possible abnormalities in certain brain regions, the circuits that interconnect these regions, and neurotransmitters (dopamine, serotinin and norepinephrine) responsible for communication of nerve cells.

Tourette’s Syndrome Diagnosis: Tics for one year, H and P,

neurological and psychiatric conditions, CT, MRI, EEG.

Symptoms: Tics (simple or complex). Simple tics are sudden, brief, repetitive

movements in limited number of muscle groups.

Complex tics are distinct, coordinated patterns of movements involving several muscle groups.

Tourette’s Syndrome Treatment: Neuroleptics (haloperidol,

pimozide), Serotonin reuptake inhibitors (clomipramine, fluoxetine, fluvoxamine, paroxetine, sertraline.

Additional: behavior treatments, biofeedback

Neuralgia Nerve pain Caused by inflammation , pressure,

toxins, and other disease. Treatment is directed toward eliminating

the cause of the pain.

Paralysis Definition: Loss of the ability to move a

body part Cause: Usually results from brain or

spinal cord injury that destroys the neurons and results in a loss of function and sensation below the level of the injury.

Types: Hemiplegia , Paraplegia, Quadriplegia

Paralysis Hemiplegia- paralysis on one side of

the body and is caused by a tumor, injury, or CVA.

Paraplegia- paralysis in the lower extremities or lower part of the body caused by spinal cord injury.

Quadriplegia-paralysis of the arms, legs, and body below the spinal cord injury.

There is NO cure. Treatment: supportive, occupational

and physical therapy.

The Neuro Assessment

The Mental Status Examination Assesses

Higher cortical functions of thinking and reasoning

Level of consciousness and orientation Attention and concentration Memory Affect and insight Speech and language Fund of knowledge and abstraction

Attention and Concentration

Attention: ability to focus on particular stimulus, task, or situation

Concentration: ability to sustain attention.

To evaluate, ask questions such as count backwards name the days of the week

Memory

Remote Memory: ask about patient’s early history

Intermediate Memory: ask patient about events of previous 5 years

Recent Memory: questions about events within the day/hour

Affect and Insight

Observe affect, or display of emotions Validated rating scales

Insight: assess and monitor cognitive, motor, or sensory function Questions such as “Why are you in the

hospital?”

Speech and Language

Aphasia: loss of speech or comprehension Three primary aphasic deficits in:

comprehension of spoken language expressive language Naming

Speech and Language

Comprehension, to evaluate ability to: Understand the written word Express ideas verbally Naming (word finding)

A – Alert V – Verbal P – Pain U – Unresponsive

Assessing AVPU

Alert

Eyes open and able to speak to you as

you approach*A patient can be alert

but agitated, confused or disoriented.

Verbal

Makes an attempt to respond only when you speak to him

Apply painful stimuli by trapezius pinch, supraorbital pressure, sternal rub, earlobe pinch or armpit pinch.

Pain

Not responsive to verbal or painful stimuli

Can lead to airway compromise

Unresponsive

Extension posturing (Decerebrate)

Flexion posturing (Decorticate)

F – Face A – Arms S – Speech T – Time

FAST Stroke Assessment

Face

Ask the patient to smile. Look for one-sided facial droop.

Arms

Ask the patient to raise their arms. Look to see if one arm drifts downward.

Ask the patient to repeat a simple phrase. Listen for word slurring and correct repeating of the phrase.

Speech

If any deficiencies are noted – facial droop, arm drift, speech slurring, TIME is CRITICAL. The clot buster TPA (tissue plasminogen activator) must be given within three hours of onset.

Time

Glasgow Coma Scale