Chapter 9 Neurology and the Nervous System

Neurology

is the medical specialty that studies the nervous system.

• Practitioners use laboratory and diagnostic tests, medical and

surgical procedures, and drugs to treat nervous system diseases

Syncope

Temporary loss of consciousness (fainting);

associated with decreased blood flow to the brain

Coma

A state of deep unconsciousness and

unresponsiveness; caused by trauma,

disease, or metabolic imbalance.

Delirium

Acute confusion, disorientation, and agitation

due to toxic levels of chemicals, drugs, or

alcohol; symptoms subside as substance is

metabolized.

Cephalalgia

A headache; a symptom with many

causes.

• cephal/o- = head

• alg/o- = pain

• -ia= condition or state

Migraine headache

Recurring headache with severe, throbbing

pain on one side of the head; (maybe) caused

by constriction and sudden dilation of arteries

in the brain.

Newer migraine treatment:

Calcitonin Gene-Related Peptide (CGRP)

CGRP is a protein that influences blood vessel

dilation

CGRP monoclonal antibodies (mAbs) block

CGRP

Meningitis

Infection and inflammation of the meninges due to a

bacterium or virus.

Encephalitis

Inflammation and infection of the brain

caused by a viral infection; involves fever,

headache, vomiting, irritability, and

photophobia.

Epilepsy

Recurring condition in which groups of neurons in the

brain spontaneously send out abnormal, uncontrolled

electrical impulses.

• Can be triggered by flashing lights, stress, lack of

sleep, or alcohol or drugs.

• Type and extent depend on the number and location

of affected neurons.

• Prior to onset the patient may experience a sensory

“warning” called an aura

Tonic-clonic

seizure

The patient is unconscious with excessive

motor activity.

• Body alternates between excess muscle tone

(tonic) and jerking muscle contractions

(clonic).

• Lasts 1-2 minutes

Absence seizure

The patient is conscious with slight or no

muscle activity.

• cannot respond to external stimuli.

• May be vacant staring, blinking, or facial tics.

• Lasts 5-15 seconds.

Complex partial

seizure

The patient has some impaired consciousness

with some involuntary contractions.

• Can involve automatisms like lip smacking.

• Lasts 1-2 minutes

Simple partial

seizure

The patient has no impaired consciousness;

lots of involuntary motor activity.

• May involve jerking the hand or turning the

head.

• Lasts 1-2 minutes

Hematoma

Localized collection of blood due to cranial

trauma or hemorrhage.

• Intraventricular hematoma

• Subdural hematoma

Concussion

Immediate loss of consciousness (LOC) due to

sudden impact of the brain with the cranium;

patient must be watched for signs of hemorrhage.

• Contusion is not accompanied by loss of

consciousness.

• Shaken baby syndrome is accompanied by

contusion, concussion, and hemorrhage

Chronic

Traumatic

Encephalopathy

(CTE)

Progressive degenerative disease.

Affects people who have had multiple

concussions and traumatic brain injuries

Cerebrovascular

accident (CVA)

Disruption or blockage of blood flow to the brain that

causes an infarct; a stroke.

• TIA may occur prior to CVA and last 24 hours.

• Hemiparesis and hemiplegia often occur.

• Other symptoms include amnesia, aphasia,

dysphasia, and dysphagia.

Anencephaly

Rare congenital condition

in which all or part of the

cranium and cerebrum are

missing; babies born with

the condition survive only a

few days.

• an- = without

• -encephaly = condition

of the brain

Amnesia

Partial or total loss of memory due to

damage to the hippocampus.

• amnes/o- = memory loss

• -ia = condition of

Aphasia

Loss of the ability to communicate verbally

or in writing

Brain tumor

Benign or malignant tumor in any area of the

brain.

• They arise in the neuroglia or meninges.

• Benign tumors are dangerous due to the

threat of increased pressure, edema, and

seizure.

• Malignant tumors may be secondary

tumors that metastasized from elsewhere.

• In general, tumors are named for the cell

from which they originate

Glioma

Benign or malignant tumor from any neuroglial cell

Ependymoma

Benign tumor from ependymal

cells in the ventricles and central

spinal canal

Astrocytoma

Malignant tumor from astrocytes

in the cerebrum

Schwannoma

Benign tumor from the Schwann

cells that produce myelin near

the cranial or spinal nerves

Meningioma

Benign tumor from the meninges

around the brain or spinal cord

Dyslexia

Difficulty reading and writing words, though visual

acuity and intelligence are normal; caused by an

abnormality of the occipital lobe.

• dys- = difficult

• lex/o- = word

• -ia = condition

Cerebral palsy (CP)

Caused by a lack of oxygen to the brain

at birth; causes spastic muscles, lack of

coordination, paralysis, seizures, and

intellectual disability.

Down syndrome

Genetic defect created by random error in cell

division; causes three copies of chromosome

21 in the genes rather than two copies.

• Affects every cell in the body.

• Most noticeable in intellectual abilities and

facial features.

Hydrocephalus

Excessive CSF or blocked CSF flow in the

brain that causes increased pressure;

ventricles distend and brain compresses.

• hydr/o- = water

• -cephalus = head

Narcolepsy

Brief episodes of involuntarily falling

asleep while engaged in daytime

activities; believed to have a

hereditary component.

• narco = to put to sleep

Neurocognitive

disorder (NCD)

Disease of the brain in which many

neurons die, the cerebral cortex shrinks in

size, and mental function deteriorates;

formerly called dementia.

• Begins with a gradual decline in abilities

with forgetfulness and difficulty making

decisions.

• Over time, more neurons are destroyed

and impairment becomes greater.

• Psychiatric symptoms may develop.

• Eventually, the patient is unable to care

for themselves or recognize family

members.

• Alzheimers, Parkinsons, and multiple

sclerosis are all examples of NCD

Alzheimer’s

disease

Hereditary dementia (mutations found on

chromosomes 1, 14, and 21. Neurons have

neurofibrillary tangles and beta amyloid senile

plaques. Also, brain has lower levels of

acetylcholine

Parkinson’s

disease

Chronic, degenerative disease caused by imbalance

in dopamine levels; in time, patient struggles with

voluntary movements

Multiple

sclerosis

Chronic, progressive autoimmune disorder in which the

body makes antibodies against myelin in CNS

There is acute inflammation and chronic myelin destruction.

• In time, demyelinated areas harden into plaques.

• Characterized by remission and gradually worsening

flare-ups.

Brain death

Irreversible loss of brain function; confirmed

by an electroencephalogram (EEG) that is

flat, indicating no brain wave activity, for thirty

minutes.

Radiculopathy

Acute or chronic condition of pressure and

pain on spinal nerve roots; caused by a

tumor, arthritis, or herniated disk.

• radix = root

Neural tube

defect

Congenital abnormality of the neural tube, an

embryonic spinal structure.

• Spina bifida: the vertebrae form incompletely

causing an opening in the vertebral column.

• The abnormal opening is covered only by skin and

meninges.

• Meningocele occurs when only the spinal cord

pushes through the defect.

• Meningomyelocele occurs when both the

meninges and the spinal cord protrude

Spinal cord

injury (SCI)

Partial or complete transection of the spinal cord.

• Nerve impulses are interrupted, causing partial or

complete loss of sensation and paralysis.

• Muscles lose tone and atrophy, known as flaccid

paralysis.

• The reflex arc of the lower spine may be intact,

causing spastic paralysis in response to pain.

• Paraplegia occurs when both legs are paralyzed.

• para = abnormal, two parts;

• pleg/o- = paralysis

• Quadriplegia occurs when both arms and both

legs are paralyzed.

• quadri- = four

Anesthesia

Loss of sensation of any type; can be

temporary or permanent.

• an- = without

• esthes/o = feeling or sensation

• -ia = condition

Paresthesia

Condition of abnormal tingling or burning

sensation on the skin; caused by chronic

nerve damage and diabetic neuropathy.

• para- = abnormal

• esthes/o- = feeling

Hyperesthesia

Increased sensitivity to touch and pain stimuli.

• hyper- = above normal

• esthes/o- = feeling or sensation

• -ia = condition or state

Neuralgia

Pain along the path of a nerve and its branches

caused by injury.

• neur/o- = nerve

• Example: Trigeminal neuralgia (tri- = three,

gemin/o- = group)

Neuritis

Infection or inflammation of a nerve;

polyneuritis affects many nerves

Neuroma

Benign tumor of a nerve

Neuropathy

General term for any type of nerve disease

or injury.

• neur/o- = nerve

• -pathy = disease

Carpal tunnel

syndrome (CTS)

Chronic condition caused by repetitive hand

and wrist motions; there is inflammation of

the forearm tendons within the carpal tunnel

of the wrist.

• carp/o- = wrist

Amyotrophic

lateral sclerosis

(ALS; Lou Gehrig

disease)

Chronic, progressive disease of the motor

nerves that go from the spinal cord to the

muscles.

• Causes muscle wasting, spasm, and

eventual paralysis.

• Sensory nerves are undamaged, so

sensation remains.

• Cognitive abilities are unaffected

Bell palsy

Weakness, drooping, or paralysis on one side

of the face due to facial nerve inflammation;

usually temporary.

Mini-Mental State

Examination (MMSE)

Tests concrete and abstract thinking

and long- and short-term memory; if a

patient can state their name, date, and

l ca i n, e are “ rien ed x 3.”

Neurologic examination

Tests coordination, sensation, balance,

and gait.

Babinski sign

Test of reflexes using the end of a percussion

hammer to stroke the sole of the foot.

• Normal (negative) test causes the toes to curl.

• Abnormal (positive) test causes the great toe to

flex and the other toes to fan out.

Glasgow coma

scale (GCS)

Numerical scale that measures the depth of a

coma; total score ranges from 1-15 and is additive

of scores for individual response scores

Alpha

fetoprotein

(AFP)

Amniotic fluid test to determine if a fetus has meningocele

or meningomyelocele.

• Fluid is collected via amniocentesis.

• amni/o- = membrane around fetus

• cent- = surgical to puncture

• Small amounts of AFP are normal in amniotic fluid.

• Large amounts are indicative of neural tube defect

Magnetic resonance

imaging (MRI)

Magnetic field and radio waves that create

image slices of the cranium, brain,

vertebral column, and spinal cord to make

a complete image

Computed axial

tomography (CAT,

CT)

X-ray slices of the cranium, brain, vertebral

column, or spinal cord used to create a

compete image; contrast dye can provide

greater detail

Positron emission

tomography (PET)

Radioactive glucose that, as it is metabolized,

releases positrons that create an image of

cellular and metabolic brain activity (see

images below)

Doppler

ultrasonography

High-frequency sound waves that produce a two-

dimensional image of stenosis, plaque, or

turbulence in carotid arteries

Arteriology

Contrast dye is injected; dye travels to carotid

artery which distributes blood throughout the

brain.

X-rays help visualize the arterial circulation

Used to look for aneurysm. stenosis, plaque, or

tumor

Lumbar puncture

(LP)

Procedure to obtain CSF for laboratory

testing or test pressure of CSF; spinal tap.

• Needle is inserted into lumbar vertebrae

Cerebrospinal

fluid (CSF)

examination

Visually examines color and clarity of CSF,

microscopically examines cells in CSF, and

chemically tests CSF for proteins.

• Normal CSF is clear and colorless.

• Pink CSF indicates a brain or spinal cord

bleed.

• Cloudy CSF indicates bacterial infection

Electroencephalo-

graphy (EEG)

Electrodes placed on the head and connected

to a machine to record the electrical activity of

the brain (see next slide)

• The pattern on the right and left sides should

be e a e; i e aren’ , i a indica e

tumor.

• Abnormal waves suggest encephalopathy,

epilepsy, or dementia

Evoked

potential

testing

EEG and stimulus used to record changes in brain

waves.

• Visual evoked response test evaluates nerve paths

from the eye to the brain.

• Brainstem auditory evoked response test evaluates

nerve paths from the ear to the brain.

• Somatosensory evoked response test evaluates nerve

paths from the extremities to the brain

Nerve

conduction

study

Two electrodes placed at measured intervals used

to determine the speed at which an electrical

impulse travels along a nerve (see image below).

• The first electrode applies an impulse.

• The second electrode receives the impulse

Polysomnography

EEG and eye movement, muscle activity,

heartbeat, and respiration measurements

taken while a patient sleeps; diagnoses

insomnia and sleep apnea.

• somnus = sleep

Spinal traction

Immobilization of fractured spine

during healing

Transcutaneous

electrical nerve

stimulation

(TENS)

Regular electrical impulses that block the

transmission of pain sensations and stimulate

e b d ’ r d c i n end r in ( ee nex

slide)

Analgesics

Take away pain associated with nervous

diseases; may be narcotic or over-the-

counter

Antiepileptics

Prevent seizures associated with epilepsy;

also called anticonvulsants

Corticosteroids

Treat inflammation associated with chronic

pain and multiple sclerosis; also treat edema

and swelling of the brain and spinal cord

Alzheimer’s

disease drugs

Inhibit an enzyme that breaks down

acetylcholine

Neuralgia and

neuropathy drugs

Include anticonvulsants, antianxiety drugs,

and antidepressants

Parkinson’s

disease drugs

Stimulate dopamine receptors

Biopsy

Removal of a mass or tumor of the brain or other part

of the nervous system; the tumor is sent to the lab for

microscopic examination.

French:

• bios = life

• opsis = sight

Aneurysmectomy

Removal of an aneurysm and repair of the

artery

Carotid endarterectomy

Removal of plaque from within the

carotid artery; restores blood flow to

the brain and decreases the

likelihood of a stroke.

• end/o- = innermost

• arter/o- = artery

• -ectomy = surgical removal

Craniotomy

Initial incision into the cranium to expose the brain

prior to any type of brain surgery (see image below)

Diskectomy

Removal of all or part of a herniated nucleus

pulposus from an intervertebral disk; relieves

pressure on nerve roots and relieves pain.

Laminectomy

Removal of the lamina; relieves pressure on the

spinal roots and decreases pain of a herniated

nucleus pulposus

Stereotactic

neurosurgery

Use of a 3D coordinate system to pinpoint the

location of a deep brain tumor; heat, cold, or

gamma rays are then used to destroy the tumor.

Ventriculoperitoneal

shunt

Tube used to remove excess CSF from

the ventricles of the brain and transport it

to the peritoneal cavity for resorption by

the blood.

• ventricul/o- = chamber that is filled

• peritone/o- = peritoneaum

AFP

alpha fetoprotein

ALS

amyotrophic lateral sclerosis

AVM

arteriovenous malformation

BAEP

brainstem auditory evoked potential

BAER

brainstem auditory evoked response

CAT, CT

computerized axial tomography

CNS

central nervous system

CP

cerebral palsy

CRPS

complex regional pain syndrome

CSF

cerebrospinal fluid

CTS

carpal tunnel syndrome

CVA

cerebrovascular accident

DT

delirium tremens

EEG

electroencephalogram; electroencephalography

GCS

Glasgow Coma Scale (or Score)

HNP

herniated nucleus pulposus

ICP

intracranial pressure

LOC

loss of consciousness

LP

lumbar puncture