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

1. NEURO-FOR-THE-NOT-SO-NEURO-MINDED

2. Let’s start from the very beginning… • How much embryology did you get in nursing school? • The sperm meets the egg…

3. 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

4. Neuroectodermal origins…skin and nervous system • Von Recklinghausen’s disease • Café au lait marks • Neurofibromas • Astrocytomas • Acoustic neuromas • Do cell phones cause brain tumors?

5. NO, cell phones do NOT cause brain tumors…cell types in CNS • Neurons • Glial cells—astrocytes, oligodendrocytes, ependymal cells • Primitive cells--medulloblasts

6. Brain tumors arise from “glial cells” • Astrocytomas • Oligodendrogliomas • Ependymomas • medulloblastomas

7. Neuroectodermal origins—the skin and nervous system • The neural tube • 1st month • Anterior neuropore (cerebral cortex) • Posterior neuropore (spinal cord)

8. Anterior neuropore defects… • Anencephaly • Encephalocele

9. Posterior neuropore defects…spina bifida syndromes • Myelomeningocele • Meningocele • Spina bifida occulta • Dermal sinus tract • Rachischisis

10. 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)

11. 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)

12. 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)

14. 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

15. The Herpes “family” • Varicella Zoster Virus (VZV) • Chickenpox is the primary infection • Shingles is the secondary infection • Rx?

16. 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

17. 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)

18. 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

19. “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

20. Abstraction… • What does “Don’t cry over spilled milk” mean? • HUH? • How are a car, plane and boat alike? • Cow, horse, and pig?

21. 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

22. 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)

23. 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

24. Brain food? How about the incredible, edible egg? Berries? Marine Omega 3 fatty acids? Olive oil? B12

25. 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

26. Clock drawing…global function

27. Frontal lobes… • Voluntary speech center—left inferior frontal gyrus • Kids • Dr. Pierre Paul Broca • Broca’s aphasia • Non-fluent aphasia—telegraphic, staccato speech

28. The homunculus (“little man”)… • Areas of greatest representation are the areas used the most

31. 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

32. UMN and CS tract synapse with LMN in the brainstem and spinal cord

33. 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

34. 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)

35. 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)

36. 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

37. “And that’s why we always stand to the side when we check reflexes…” • Hyperreflexia

38. Causes of UMN signs and symptoms? • Head injury • Spinal cord injury below the level of the lesion • Stroke • Tumor • Epidural • Subdural

39. Damage to the Lower Motor Neurons and the peripheral nerve to muscle • NO INPUT • Loss of reflexes (areflexia) • Atonia/hypotonia • Flaccidity/muscle atrophy

40. UMN vs. LMN

41. Reflex Chart—normal vs. stroke • Achilles, patellar, biceps, triceps (S1,2; L3,4; C5,6; C7,8) • Normal--2+ to 3+

42. 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

43. Reflex Chart—slipped disc at L5 compresses S1, S2 • Areflexia on the same side as the slipped disc

44. 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!”

45. 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

46. 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

47. Clonal selectivity • They stick their nose where the “sun don’t shine” and say… “You’re the one for me…”

48. Oops. • Why don’t humans do that? Well we kind of do…

49. Because we have a “mother”—the frontal lobe… • “Don’t even think about it…”

50. 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)