Transcript NEURO-FOR-THE-NOT-SO-NEURO-MINDED

NEURO-FOR-THE-NOT-SONEURO-MINDED
Let’s start from the very beginning…
• How much embryology did you get in nursing
school?
• The sperm meets the egg…
1+1=1
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1 egg + 1 sperm = 1 zygote
2 cells, 4 cells, 8 cells, 16, 32, 64, 128
BLAST-o-cyst
Let the layers begin
Ectoderm (outer), endoderm (inner), mesoderm (filler)
Ectodermal origins—skin and nervous system
Neuroectodermal origins…skin and
nervous system
• Von Recklinghausen’s
disease
• Café au lait marks
• Neurofibromas
• Astrocytomas
• Acoustic neuromas
• Do cell phones cause
brain tumors?
NO, cell phones do NOT cause brain
tumors…cell types in CNS
• Neurons
• Glial cells—astrocytes, oligodendrocytes,
ependymal cells
• Primitive cells--medulloblasts
Brain tumors arise from “glial cells”
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Astrocytomas
Oligodendrogliomas
Ependymomas
medulloblastomas
Neuroectodermal origins—the skin and
nervous system
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The neural tube
1st month
Anterior neuropore (cerebral cortex)
Posterior neuropore (spinal cord)
Anterior neuropore defects…
• Anencephaly
• Encephalocele
Posterior neuropore defects…spina bifida
syndromes
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Myelomeningocele
Meningocele
Spina bifida occulta
Dermal sinus tract
Rachischisis
Risk factors for neural tube defects…
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Folic acid deficiency
Drugs (anticonvulsants, ETOH, MTX, OCs*)
Obesity
Maternal age
Hyperglycemia
Hyperthermia
Prevention -- *BeYaz (new COC with folic acid)
Dermatomes…sensory input to spinal cord and
brainstem segments
• C3,4 (shoulder* and
referred pain)
• T4 (nipple)
• T10 (umbilicus)
• L1 (bikini underwear)
• L3,4 (knees)
• S1,2 (back of the leg)
• S3-5 (perineum)
Herpes viruses and the nervous system…
• The Herpes “Family”—HSV-1, HSV-2, VZV are
all neurotrophic viruses
• HSV-1
• Prefers to lie dormant in the trigeminal nerve
dorsal root ganglion
• V1, V2, V3 (Ophthalmic, maxillary,
mandibular)
The Herpes family…
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HSV-2—the dorsal root ganglion of S3,4,5
VZV—varicella zoster virus
Shingles or “hell’s fire”
V1 of the Trigeminal nerve
The Herpes “family”
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Varicella Zoster Virus (VZV)
Chickenpox is the primary infection
Shingles is the secondary infection
Rx?
The antiherpetics—the “cy{i}clovirs”
• Acyclovir (Zovirax)(4000/d)
• Famciclovir (Famvir)(750/d)
• Valacyclovir (Valtrex)(3000/d)
Tx must be started within 48-72 hours after the first
signs of a rash appear.
• +Prednisone
PREVENTION
• Zostavax (Merck) to reduce the incidence of Herpes
Zoster (shingles/Hell’s fire) in people over 60 (14 x
stronger than Varivax)(risk reduction—50%); reduces
severity and decreases post-herpetic neuralgia
Chronic neuropathic pain
• Post-herpetic neuralgia follows a dermatome
distribution
• Drugs to Tx
• Antidepressants that boost norepinephrine and
serotonin in the descending pain pathways of the
brainstem--Amitriptyline (Elavil), duloxetine
(Cymbalta)
• Anticonvulsants—gabapentin (Neurontin), pregabalin
(Lyrica)
THE FRONTAL LOBES…
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Prime real estate of the brain
Comprises one-third of the cerebral cortex
Who’s your Mama? The frontal lobe is your “Mother”
“No, negative, don’t, stop…” She is inhibitory..
Executive functions—socialization, judgment, forward
planning
“Mom” and socialization
• Frontal lobes are not mature in babies and
young children…it actually takes about 17-22
years for full maturity of the human frontal
lobes
• The TEENAGE brain
• “Don’t scratch, don’t pick, don’t dig..”
• Judgment
• Insight
Abstraction…
• What does “Don’t cry over spilled milk”
mean?
• HUH?
• How are a car, plane and boat alike?
• Cow, horse, and pig?
FRONTAL LOBES…
• Alcohol and socialization
• Loss of inhibitions with .05 blood alcohol
levels
• You lose your “FILTER”…MOM
• Baso-orbital region and the loss of inhibitions
in patients with dementia/Traumatic Brain
Injury
Acetylcholine…cognitive function
• Alzheimer’s disease—90% of acetylcholine is lost with
destruction of brain tissue
• 1st described 1906
• Amyloid plaques and neurofibrillary tangles
• BAP v\s. TAU
• Acetylcholinesterase inhibitors such as donepezil (Aricept)
• Drugs that block NMDA receptors (memantine/Namenda)
CT scan of the demented brain
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Cortical atrophy; Sulcal widening
Atrophy of gyri
Brain weight
Alzheimer’s dementia, HIV dementia,
dementia pugilistica, nutritional dementia,
Traumatic Brain Encephalopathy
Brain food? How about the incredible, edible egg?
Berries? Marine Omega 3 fatty acids? Olive oil? B12
Quick mental status check…
• Time and Change Test
Clock with hands—What time is it?
3 quarters, 7 dimes, 7 nickels—Can you give
me change in the amount of $1.00?
97% negative predictive value if correct on both
parts of the test
Clock drawing…global function
Frontal lobes…
• Voluntary speech center—left inferior frontal
gyrus
• Kids
• Dr. Pierre Paul Broca
• Broca’s aphasia
• Non-fluent aphasia—telegraphic, staccato
speech
The homunculus (“little man”)…
• Areas of greatest
representation are the
areas used the most
Frontal lobes…
• Pre-central gyrus (motor cortex—upper motor neurons)—
contralateral control
• Right pre-central gyrus controls left side
• Left pre-central gyrus controls right side
• Voluntary movement centers bilaterally
• The neurons located in the pre-central gyrus are known as
“Upper Motor Neurons” or UMNs
• The UMNs send their message through the Corticospinal tract
down through the white matter, into the brainstem where the
pathway decussates or crosses to the other side in the
medulla
UMN and CS tract synapse with LMN
in the brainstem and spinal cord
The reflex arc…
• Sensory information into the spinal cord
• Synapses in same spinal cord segment
• Sent right back out via lower motor neuron to
the…
• Peripheral motor nerve
• S1,2 (Achilles); L3,4 (Patellar); C5,6 (Biceps);
C7,8 (Triceps)
• 50% of the elderly (over 75) do NOT have an
Achilles reflex
Dermatomes…sensory input to spinal cord and
brainstem segments
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C3,4 (shoulder* and referred pain)
T4 (nipple)
T10 (umbilicus)
L1 (bikini underwear)
L3,4 (knees)
S1,2 (back of the leg)
S3-5 (perineum)
Damage to the upper motor neurons/CS
tract
Signs and symptoms of UMN disease include:
• Contralateral hemiparesis
• Pronator drift (weakness)
• Hemiparalysis (spastic
paralysis)
• + Babinski (extensor plantar reflex)—is it
present or absent? (not positive or negative)
Josef Francois Felix Babinski
• The Babinski reflex
• Babinski, Josef Francois Felix,
(1857-1932), a Parisian of Polish
origin, described the famous
abnormality of the extensor
plantar response seen in
disorders involving the
corticospinal tracts in a series of
short articles beginning in 1896.
• English physicians used their
“Rolls Royce” key
• “And that’s why we
always stand to the side
when we check
reflexes…”
• Hyperreflexia
Causes of UMN signs and symptoms?
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Head injury
Spinal cord injury below the level of the lesion
Stroke
Tumor
Epidural
Subdural
Damage to the Lower Motor Neurons
and the peripheral nerve to muscle
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NO INPUT
Loss of reflexes (areflexia)
Atonia/hypotonia
Flaccidity/muscle atrophy
UMN vs. LMN
Reflex Chart—normal vs. stroke
• Achilles, patellar, biceps,
triceps (S1,2; L3,4; C5,6;
C7,8)
• Normal--2+ to 3+
Reflex Chart—post-stroke
• Contralateral to stroke
• Areflexia (shock after a
stroke)—0
• As the brain recovers, and
there’s no “mother”
(inhibition), the reflexes are
uncontrolled
• Hyperreflexia 4+
• TOES up
Reflex Chart—slipped disc at L5
compresses S1, S2
• Areflexia on the same side
as the slipped disc
TEMPORAL LOBES…
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Superior temporal gyrus
Wernicke’s area—reception of speech
Do you understand what I am telling you?
Interpretation of speech and sounds
Wernicke’s aphasa– “I’m going to the
kredistan to get a preeble…want one?”
• Jargon aphasia— “Ca, ca, ca, ca CAH!”
TEMPORAL LOBES…
• Cranial Nerve VIII (Acoustic Nerve) “hears” for
you…(primary sensory modality)
• The Superior Temporal Gyrus (STG) interprets
what you are hearing (higher cortical function)
• What am I hearing?
• Coins jingling in your pocket
• Auditory agnosia
TEMPORAL LOBES…
• Cranial Nerve I “smells” for you (primary sensory modality)
• The uncus interprets what you are smelling (higher cortical
function)
• The uncus is connected to the hippocampus (memory)
• Cranial Nerve 0 (Nervus Terminalis)—runs in tandem with
CN1; connects to the hypothalamic area of sexual function-pheromones
Clonal selectivity
• They stick their nose where the “sun don’t
shine” and say… “You’re the one for me…”
Oops.
• Why don’t humans do that? Well we kind of
do…
Because we have a “mother”—the
frontal lobe…
• “Don’t even think about
it…”
TEMPORAL LOBES…
• Inferior surface of frontal and temporal lobes-a meningioma displacing the olfactory nerve
(cranial nerve 1)
• Loss of smell
• Loss of inhibitions (baso-orbital frontal lobe)
TEMPORAL LOBES…
• An “aura”—the beginning of a temporal lobe
seizure with a funny taste or smell (rotten
eggs)
• Anosmia—loss of smell or the loss of the
ability to interpret smell may be the first sign
of a neurodegenerative disease (PD, DAT)
• **auras are also associated with migraine
headaches…migraine with aura is a major risk
factor for strokes
TEMPORAL LOBES…
• Déjà vu—feeling like you’re been there before
• Jamais vu—familiar place becomes totally
unfamiliar
• Illusions—distortion of an ongoing stimuli
(marijuana)
• Hallucinations—seeing or hearing something
that is not there
Hallucinations
• Drugs and hallucinations—boosting dopamine
triggers hallucinations—drugs for Parkinson’s disease,
hallucinogenic drugs (LSD, peyote) and mushrooms,
ETOH withdrawal, Herpes encephalitis
• Schizophrenia—dopamine and serotonin excess;
Drugs used to treat schizophrenia block dopamine
and serotonin; glutamate may play a role as well
• Causes of schizophrenia? Genetic? Maternal infection
during a critical period of fetal brain development?
TEMPORAL LOBES…
• Self-preservation and preservation of the
species—the autonomic nervous system
• The 4 F’s…fight, flight
• Feeding activities
• And….
And…
• Sexual Function
Sexual function in the brain and
dopamine…
• Dopamine plays a major role in the pleasure
centers of the brain, including sexual pleasure
• SSRIs (prescribed for depression) increase
serotonin and you’re happy, but…
• When serotonin goes up, dopamine goes
down (in as many as 40-60% of patients on
the SSRIs)
TEMPORAL LOBES…
• Self-preservation and preservation of the
species—The other 2 F’s
• Fight—Flight (epi, NE)
• Episodic dyscontrol syndrome—TBI patients
Dopamine and the nucleus accumbens
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Addiction and dopamine
Nicotine
Alcohol
Methamphetamine
French fries
The earlier you start, the greater the addiction
potential
TEMPORAL LOBES…
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Recent memory (hippocampus)
Remember 3 items…
Red ball, clock, tennis shoe
Repeat them after me…
Red ball, clock, tennis shoe
Continue with exam for 10 minutes and ask
them to repeat those 3 items
Loss of hippocampal cell function
• Loss of recent memory
• This is the first neurologic function to go with
the aging process
• When does this process begin?
• When do you reach your peak mental
capacity?
Loss of neurons and the hippocampus
• cortisol receptors and the hippocampus
• Chronic stress and depression
• Post-traumatic stress disorder
NEUROGENESIS
• November 1, 1998
• Dr. Fred Gage and a colleague at the
Karolinska Institute in Sweden discovered that
neurons CAN and DO regenerate
• Specifically in the hippocampus of the brain
• How can neurogenesis be stimulated?
Neurogenesis
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SAY YES TO DRUGS!
(antidepressants and statins)
Exercise
Meditation
TEMPORAL LOBES…
• Partial complex seizures—altered state of
consciousness; most common cause is a
closed head injury; also consider a history of
shaken baby syndrome; mid-forceps delivery
• Automatisms
• Semi-purposeful behavior
• Treatment of partial complex seizures
PARIETAL LOBES…
• Integration of tactile sensations—touch,
pressure, vibration, and proprioception (do
you know where your body parts are right
now?)
PARIETAL LOBES..testing
• Double simultaneous stimuli—kids vs. adults
• Touch two areas at the same time..
• Kids will always neglect their body and will
recognize touch on the face
• The neglect syndrome in adults
PARIETAL LOBES..testing
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Ability to localize stimuli
Sharp vs. dull
Tests for proprioception
Graphesthesia
Tattoos may give a false negative
• Apraxia—example: a dressing apraxia,
ideomotor apraxia,
constructional apraxia
OCCIPITAL LOBES…
• Visual integration—problems manifest as
cortical blindness (visual agnosia)
• Do you see this object?
• If they can see it, CN2 (the optic nerve)
• What is it? The occipital cortex
QUIZ…
• What were those 3 items I asked you to
remember?
The BASAL GANGLIA…
• The 2nd area of the motor “triad”
The basal ganglia…
• Paired nuclei at the base of
the brain
• 50:50 balance between
acetylcholine and dopamine
• All dopamine is made in the
substantia nigra from
melanin
• Gamma-amino butyric acid
(GABA) keeps dopamine in
check
Caudate nucleus
Globus pallidus
Substantia nigra
Subthalamic nucleus
The BASAL GANGLIA
The functions of the basal ganglia depend on a
balance between various neurotransmitters
GABA-↓
dopamine:acetylcholine
50:50
When this balance is disturbed, movement
disorders occur
The BASAL GANGLIA…
• Control of movement, initiation and cessation
of movement
• Postural reflexes—the righting reflex
Dopamine
• Dopamine levels decrease with aging
gradually—we all slow down (loss of 45%)
• Dopamine loss of greater than 80% results in
signs and symptoms of Parkinson’s disease
Clinical symptoms
• Resting tremor (70%)—unilateral or bilateral
(unopposed acetylcholine in Parkinson’s patients)
• Unilateral presentation with Parkinson’s; bilateral
presentation with Parkinsonism from drugs
• Rigidity (decreased dopamine) (vs. spasticity of stroke
patients)
• Loss of voluntary movements (spontaneous)
• Bradykinesia (decreased dopamine) (check gait)
• Postural instability (sternal push)
• Presence of severe seborrheic dermatitis suggests PD
(unopposed acetylcholine)
• Anosmia
Huntington’s chorea…chromosome #4
• Excess dopamine due to the loss of GABAminergic input from the degeneration of the
caudate nucleus
• Chorea—rapid, jerky movements of muscle
groups
• Dementia
• Neuroleptic drugs to block dopamine
Other movement disorders
• Tourette’s syndrome (Giles de Tourette)
• Athetoid (slow, writhing movements) cerebral
palsy—kernicterus (elevated bilirubin levels in
newborns)
• Tardive dyskinesia
The cerebellum—the 3rd area of the motor
“triad”
The cerebellum…
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Coordination
Synergy
Balance
Equilibrium
Muscle tone
The cerebellum…
• Romberg test—stand up with your feet
together and close your eyes
• Tandem walk
• Close your eyes and touch your finger to your
nose (lighting on an object)
• Rapid alternating movements
The cerebellum…
• Truncal ataxia—wide, staggering gait
• Dysdiadochokinesia—inability to make rapid
alternating movements
• Dysmetria—inability to light on an object
(touching nose with finger, for example)
• Dysarthria—”scanning speech”
• Puppet-like movements
The cerebellum…
• THINK BOOZE and the CEREBELLUM
The CEREBELLUM…
• Multiple sclerosis
• Down syndrome
• Spinocerebellar ataxia
• (The cerebellum is not “strictly” motor—it also
monitors sensory input from “the outside”—may
play a role in autism and schizophrenia)
The BRAINSTEM…(the “bulb”)
• Cardiorespiratory center—C2, C3 “Hangman’s fracture)
• ARAS (Ascending reticular activating system)
• Cranial Nerves III – XII (I and II are not located in the
brainstem and have only a “central component”)
• III – XII have their nuclei in the brainstem but send their
information via the peripheral nerves
• Hence, III – XII have the capacity to “regenerate” their
peripheral components
Example of peripheral vs. central
• Amyotrophic Lateral Sclerosis—Lou Gehrig’s
disease—central nervous system involvement of
central brainstem nuclei (IX and X)—swallowing,
speech
• Guillain-Barré syndrome (GBS)—peripheral
demyelination of XI and X (the bulbar
presentation)—difficulty swallowing, but patients
have the capacity to recover
• Multiple Sclerosis—central demyelination
• GBS—peripheral demyelination (undercooked
chicken)
The BRAINSTEM…(the “bulb”)
• II (Optic) and III (Oculomotor)—light reflex,
accommodation, and the optic disk (papilla)
• Papilledema—swelling of the optic disk
• Usually, but not always, indicates cerebral
edema
• What are the circumstances?
The BRAINSTEM…(the “bulb”)
• II (Optic) and III (Oculomotor)—light reflex,
accommodation, and the optic disc (papilla)
• The Argyll Robertson pupil—a pupil that will
accomodate accommodate but not react to
light—aka as “the prostitute’s pupil)
The BRAINSTEM…
• CN III, IV, VI—follow my finger (extraocular
movements)
• End-positional nystagmus
• Ptosis
The BRAINSTEM…
• V (Trigeminal) and VII (Facial)
• Corneal reflex—touch cornea with a cotton
wisp and the patient blinks; if the patient is in
a coma, use a syringe with saline drops
• VII (Bell’s palsy)—paralysis of facial muscles –
smile, puff cheeks, frown
• Cause of Bell’s Palsy? Virus usually, also
consider Borrelia burgdorferi if in an endemic
area for deer ticks
The BRAINSTEM…
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IX (Glossopharyngeal) and X (Vagus)
The gag reflex
The uvula
Closing off nasopharynx—say “K, K, K”
Cleft palate
The BRAINSTEM…
• CN XII (Hypoglossal)—tongue movement and
strength
• Left, right, midline
The PERIPHERAL NERVOUS SYSTEM
• Dermatome chart
• Stocking-glove distribution with peripheral
neuropathy
• The reflex arc—S1,2 (Achilles), L3,4(Patellar),
C5,6 (Biceps),
• C7,8 (Triceps)
Peripheral neuropathy
“Where in the H#!l did I put that sewing needle?”
Disease of the lower motor neuron or it’s pathway to
the peripheral nervous system
• Peripheral neuropathy
• Diabetes, alcoholism (thiamine deficiency—
B1), B12 deficiency
• Heavy metals
• Chemotherapy
• others
Neuromuscular junction
• Disease of the neuromuscular junction—
myasthenia gravis
• Muscle weakness—consider thyroid disease,
drug-induced myopathy, polymyositis,
inherited muscular dystrophies
• "No study has shown that a drug can do what
we showed is possible with exercise", said
study leader, J. Carson Smith. "People with
MCI are on a very sharp decline in their
memory function, so being able to improve
their recall is a very big step in the right
direction.“
• Journal of Alzheimer’s Disease, July 2013
• Not only did the cardiovascular fitness
improve by ten percent in both groups during
this time, but their cognitive abilities also
improved. The memory recall function was
enhanced and the brain worked more
efficiently. At the end of the study, the
subjects needed fewer neural resources to
master the same memory tasks.
Thanks.
• Barb Bancroft, RN, MSN, PNP
• CPP Associates, Inc.
• Chicago, IL.
• [email protected]
• www.barbbancroft.com