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NEURO-FOR-THE-NOT-SO-NEURO-MINDED
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Let’s start from the very beginning…
How much embryology did you get in nursing school? The sperm meets the egg…
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1 + 1 = 1 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
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Neuroectodermal origins…skin and nervous system
Von Recklinghausen’s disease Café au lait marks Neurofibromas Astrocytomas Acoustic neuromas Do cell phones cause brain tumors?
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NO, cell phones do NOT cause brain tumors…cell types in CNS
Neurons Glial cells—astrocytes, oligodendrocytes, ependymal cells Primitive cells--medulloblasts
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Brain tumors arise from “glial cells”
Astrocytomas Oligodendrogliomas Ependymomas medulloblastomas
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Neuroectodermal origins—the skin and nervous system
The neural tube 1st month Anterior neuropore (cerebral cortex) Posterior neuropore (spinal cord)
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Anterior neuropore defects…
Anencephaly Encephalocele
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Posterior neuropore defects…spina bifida syndromes
Myelomeningocele Meningocele Spina bifida occulta Dermal sinus tract Rachischisis
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Risk factors for neural tube defects…
Folic acid deficiency Drugs (anticonvulsants, ETOH, MTX, OCs*) Obesity Maternal age Hyperglycemia Hyperthermia Prevention -- *BeYaz (new COC with folic acid)
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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)
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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)
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The Herpes family… HSV-2—the dorsal root ganglion of S3,4,5
VZV—varicella zoster virus Shingles or “hell’s fire” V1 of the Trigeminal nerve
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The Herpes “family” Varicella Zoster Virus (VZV)
Chickenpox is the primary infection Shingles is the secondary infection Rx?
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The antiherpetics—the “cy{i}clovirs”
Acyclovir (Zovirax)(4000/d) Famciclovir (Famvir)(750/d) Valacyclovir (Valtrex)(3000/d) Tx must be started within 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
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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)
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THE FRONTAL LOBES… 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
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“Mom” and socialization
Frontal lobes are not mature in babies and young children…it actually takes about years for full maturity of the human frontal lobes The TEENAGE brain “Don’t scratch, don’t pick, don’t dig..” Judgment Insight
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Abstraction… What does “Don’t cry over spilled milk” mean? HUH?
How are a car, plane and boat alike? Cow, horse, and pig?
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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
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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)
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CT scan of the demented brain
Cortical atrophy; Sulcal widening Atrophy of gyri Brain weight Alzheimer’s dementia, HIV dementia, dementia pugilistica, nutritional dementia, Traumatic Brain Encephalopathy
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Brain food. How about the incredible, edible egg. Berries
Brain food? How about the incredible, edible egg? Berries? Marine Omega 3 fatty acids? Olive oil? B12
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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
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Clock drawing…global function
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Frontal lobes… Voluntary speech center—left inferior frontal gyrus
Kids Dr. Pierre Paul Broca Broca’s aphasia Non-fluent aphasia—telegraphic, staccato speech
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The homunculus (“little man”)…
Areas of greatest representation are the areas used the most
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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
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UMN and CS tract synapse with LMN in the brainstem and spinal cord
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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
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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)
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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)
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Josef Francois Felix Babinski
The Babinski reflex Babinski, Josef Francois Felix, ( ), 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
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“And that’s why we always stand to the side when we check reflexes…”
Hyperreflexia
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Causes of UMN signs and symptoms?
Head injury Spinal cord injury below the level of the lesion Stroke Tumor Epidural Subdural
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Damage to the Lower Motor Neurons and the peripheral nerve to muscle
NO INPUT Loss of reflexes (areflexia) Atonia/hypotonia Flaccidity/muscle atrophy
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UMN vs. LMN
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Reflex Chart—normal vs. stroke
Achilles, patellar, biceps, triceps (S1,2; L3,4; C5,6; C7,8) Normal--2+ to 3+
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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
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Reflex Chart—slipped disc at L5 compresses S1, S2
Areflexia on the same side as the slipped disc
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TEMPORAL LOBES… 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!”
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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
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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
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Clonal selectivity They stick their nose where the “sun don’t shine” and say… “You’re the one for me…”
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Oops. Why don’t humans do that? Well we kind of do…
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Because we have a “mother”—the frontal lobe…
“Don’t even think about it…”
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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)
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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
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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
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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?
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TEMPORAL LOBES… Self-preservation and preservation of the species—the autonomic nervous system The 4 F’s…fight, flight Feeding activities And….
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And… Sexual Function
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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)
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TEMPORAL LOBES… Self-preservation and preservation of the species—The other 2 F’s Fight—Flight (epi, NE) Episodic dyscontrol syndrome—TBI patients
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Dopamine and the nucleus accumbens
Addiction and dopamine Nicotine Alcohol Methamphetamine French fries The earlier you start, the greater the addiction potential
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TEMPORAL LOBES… Recent memory (hippocampus) Remember 3 items…
Red ball, clock, tennis shoe Repeat them after me… Continue with exam for 10 minutes and ask them to repeat those 3 items
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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?
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Loss of neurons and the hippocampus
cortisol receptors and the hippocampus Chronic stress and depression Post-traumatic stress disorder
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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?
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Neurogenesis SAY YES TO DRUGS! (antidepressants and statins) Exercise
Meditation
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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
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PARIETAL LOBES… Integration of tactile sensations—touch, pressure, vibration, and proprioception (do you know where your body parts are right now?)
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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
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PARIETAL LOBES..testing
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
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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
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QUIZ… What were those 3 items I asked you to remember?
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The BASAL GANGLIA… The 2nd area of the motor “triad”
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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
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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
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The BASAL GANGLIA… Control of movement, initiation and cessation of movement Postural reflexes—the righting reflex
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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
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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
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Huntington’s chorea…chromosome #4
Excess dopamine due to the loss of GABA-minergic input from the degeneration of the caudate nucleus Chorea—rapid, jerky movements of muscle groups Dementia Neuroleptic drugs to block dopamine
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Other movement disorders
Tourette’s syndrome (Giles de Tourette) Athetoid (slow, writhing movements) cerebral palsy—kernicterus (elevated bilirubin levels in newborns) Tardive dyskinesia
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The cerebellum—the 3rd area of the motor “triad”
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The cerebellum… Coordination Synergy Balance Equilibrium Muscle tone
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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
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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
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The cerebellum… THINK BOOZE and the CEREBELLUM
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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)
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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
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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)
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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?
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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)
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The BRAINSTEM… CN III, IV, VI—follow my finger (extraocular movements)
End-positional nystagmus Ptosis
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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
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The BRAINSTEM… IX (Glossopharyngeal) and X (Vagus) The gag reflex
The uvula Closing off nasopharynx—say “K, K, K” Cleft palate
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The BRAINSTEM… CN XII (Hypoglossal)—tongue movement and strength
Left, right, midline
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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)
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Peripheral neuropathy “Where in the H#. l did I put that sewing needle
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Peripheral neuropathy
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
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Neuromuscular junction
Disease of the neuromuscular junction—myasthenia gravis Muscle weakness—consider thyroid disease, drug-induced myopathy, polymyositis, inherited muscular dystrophies
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"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
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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.
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Thanks. Barb Bancroft, RN, MSN, PNP CPP Associates, Inc. Chicago, IL.
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