Higher Mental States, Sleep, Diseases of the Central Nervous System

1. Higher Mental States, Sleep, Diseases of the Central Nervous System

2. For Study Guides go to... http://drgrantsap.blogspot.com/ Higher Mental States, Sleep, Diseases of the Central Nervous System

3. Higher Mental States, Sleep, Diseases of the Central Nervous System OBJECTIVES: Identify each of the four types of Brain Waves Define Epilepsy Define Consciousness, Syncope, Coma Differentiate between the stages of Sleep Understand how the brain processes Language Differentiate between the types of Memory Understand the structure and function of the BBB Study different conditions that can affect the Brain

4. Brain Waves The brain's electrical activity is monitored by an electroencephelogram (EEG) Brain waves are generated by synaptic activity in the cortex. Not by AP's in the white matter Brain wave frequency is expressed in Hz; number of peaks in one second Brain wave amplitude measures the INTENSITY of each wave, not the number. How high the peaks are, how low the lows are Amplitude is usually HIGHER in sleep states

5. Brain Waves There are four types of Brain waves: Alpha Beta Theta Delta

6. Brain Waves Alpha waves: 8-13 Hz Regular and rhythmic Low amplitude, synchronous Calm, relaxed, awake

7. Brain Waves Beta waves: 14-30 Hz Rhythmic, slightly irregular Higher frequency than alpha waves Mentally alert, concentrating Also seen in REM sleep

8. Brain Waves Theta waves: 4-7 Hz Highly irregular pattern Common in children Rare in adults, seen in stage 2 and 3 sleep

9. Brain Waves Delta waves: < 4 Hz Seen in deep sleep or anesthesia If see in awake adults = brain damage

10. Brain Waves EEG's are used to diagnose epilepsy and sleep disorders. If the frequency is too high = epilepsy A “flat” EEG = brain dead

11. Epilepsy Epilepsy is characterized by uncontrolled excessive activity of either part or all of the CNS Attacks occur when the basal level of excitability of the part of the NS that is susceptible to the epileptic state rises above critical threshold (Like AP's all or nothing response. Once it hits threshold, there's no stopping it.)

12. Types of Epilepsy Tonic-Clonic (Grand Mal) Most severe seizures Bones can sometimes break due to extreme muscle contraction Loss of consciousness can occur Loss of B&B, tongue biting common

13. Types of Epilepsy Tonic-Clonic progression: Seizure comes on, lasts from a few seconds to 3-4 minutes, muscles relax, patient is disoriented and typically exhausted post-attack Sometimes preceded by an “aura”; a sensory hallucination of smell, taste, or flashes of light

14. Tonic-Clonic Do's and NEVER EVER EVEREVER Do's...

15. Tonic-Clonic Do's and NEVER EVER EVEREVER Do's... Never, EVER EVEREVEREVER put ANYTHING in the patient's mouth NEVER attempt to restrain the patient NEVER, EVER, EVAH leave the patient unattended until they have fully recovered DO place a pillow or soft object under the patient's head DO let the seizure run it's course DO gently roll the patient onto their left side (recovery postion) if possible. Don't force it. Should you call an ambulance or not?

16. Types of Epilepsy (cont.) Petit-Mal “Absence Syndrome” The patient “checks out” or “blanks” for a few seconds to a couple minutes Picks up exactly where they left off Sometimes experiences facial twitches “Spike and dome” EEG Usually appear in childhood and disappear by 30yoa

17. Consciousness Conscious awareness of sensations, voluntary initiation and control of movement, capabilities of high function such as memory, logic, and judgment, etc. Syncope (fainting) is a loss of consciousness usually due to inadequate cerebral blood flow resultant from low blood pressure. ANS? Coma is total unresponsiveness to sensory stimuli. Irreversible coma occurs when irreversible brain damage occurs

18. Sleep/Wake Cycles Two types of sleep; NREM and REM NREM has four stages: Stage 1 Stage 2 Stage 3 slow wave Stage 4 slow wave

19. Sleep/Wake Cycles NREM Stage 1 Relaxation begins Alpha waves Easy to wake up “drifting” while driving

20. Sleep/Wake Cycles NREM Stage 2 Irregular EEG with short bursts ”More Under”, harder to arouse

21. Sleep/Wake Cycles NREM Stage 3 First stage of slow wave sleep Delta and Theta waves appear Vital signs decrease Less prone to wake up Healing, regeneration probably occur here.

22. Sleep/Wake Cycles NREM Stage 4 Second stage of slow wave sleep Primarily Delta waves Hard to arouse Bed-wetting, night terrors, sleepwalking/talking, etc

23. Sleep/Wake Cycles REM Sleep Once stage 4 is reached, the brain quickly cycles back through the previous waves into REM sleep Vital signs increase Oxygen use dramatically increases Skeletal muscles are actively inhibited Dreaming occurs Takes between 60-90 minutes to get here, lasts between 5-50 minutes.

24. Sleep/Wake Cycles RECAP:

25. When things go awry... Narcolepsy Go into REM from the fully awake state. Last 15 minutes, typically Triggered by pleasant events Cataplexy is a type of narcolepsy in which all voluntary motor activity is lost temporarily but the patient remains fully aware and conscious The problem appears to be the hypothalamus doesn't secrete peptides called orexins that act as a “wake-up” chemical

26. When things go awry... Insomnia A chronic condition in which the patient cannot get the quality or amount of sleep necessary to function adequately during the day Tend to rely on hypnotics which can make the problem worse in some cases The most common causes of insomnia are emotional or psychological disturbance Anxiety and depression can cause us to wake early or have trouble falling asleep

27. When things go awry... Sleep apnea A temporary cessation of breathing during sleep Patient awakens repeatedly throughout the night due to hypoxia Most common form is obstructive sleep apnea, caused by laxity in the muscles or ligaments of the upper airway, causing obstruction Associated with obesity, exacerbated by alcohol and other CNS depressants Weight loss is the most effective treatment

28. Language Language (Guyton 670) One of the most important functions of the brain The entire left cortical association areas are involved with language The two primary regions involved in language are Broca's speech area (frontal lobe) and Wernicke's area (temporoparietal lobes)

29. Language Broca's speech area is involved with motor/physical expression of language. If lesions are preset in Broca's, the patient can understand language, but cannot speak. Wernicke's area is involved with the sensory aspect of language Patients with lesions in Wernicke's area cannot understand language, but can speak, but their speech makes no sense The right cortical association areas are involved with interpreting body language and expression of emotion in our speech

30. Memory There are two stages of memory Short-term/working memory Long-term memory

31. Memory Short-Term/working memory Preliminary step to long-term memory Capacity is limited to seven or eight chunks of information

32. Memory Long-term memory Limitless capacity Long-term memories can be forgotten. Use it or lose it Storage and retrieval of memory declines with age. You can't teach an old dog new tricks!

33. Memory Storage of memory All information that comes in is processed, and around 5% is selected for storage in STM Information is transferred to long-term memory, but is based on many factors

34. Storage of Memory Emotional state This is the most important and most effective means of transferring something to long-term memory Norepinephrine is released when we are stressed or in fight/flight 9/11/2001

35. Storage of Memory Rehearsal Repetitive use and association of memory “imprints” it on our long-term memory Technology will be the downfall of humankind

36. Storage of Memory Association Tying new information to old information helps us to remember facts Who is this woman?

37. Storage of Memory Automatic Memory “Can't remember names, but I never forget a face” We don't consciously try to remember something, but we do anyway I may wear this shirt today on another day. You may not remember this lecture, but you'll remember my shirt

38. Categories of Memory Four types of memory Declarative memory What you're doing in this class! Associated with conscious learning of explicit information; names, faces, words, etc. Related to our conscious thoughts and our ability to manipulate symbols and language

39. Categories of Memory Non-Declarative Memory Procedural skills Driving a car Playing a musical instrument Motor memory Riding a bike Skateboarding GOLF!!! Emotional Memory Fear of Dogs Acquired through experience and repetition

40. Structures Involved in Memory Memory is stored in the association cortices and is accessed and “put together” by the hippocampus (Temporal Lobe) Visual memories are stored in the VAC Auditory memories are stored in the AAC General Sensory memories are stored in the SAC Emotional memories are stored in the limbic system

41. When things go awry... again If one hippocampal or temporal region is damaged, slight memory loss occurs If both are damaged, widespread amnesia will occur Old memories aren't lost, but new memories can't be formed. (Anterograde Amnesia) Anterograde amnesia patients can still learn skills, but cannot form declarative memories.

42. The Blood-Brain Barrier (BBB) Composed of 3 layers: The capillary endothelium Thick basal lamina around the outside of each capillary The bulbous feet of the astrocytes attached to the capillaries

43. The Blood-Brain Barrier (BBB) The astrocytes supply input to the capillary wall, forcing the capillaries to form tight junctions with one another, preventing the entrance of certain products The BBB is selective, in that it allows certain substances in via facilitated diffusion Most metabolic wastes, proteins, toxins and drugs are denied entry to brain tissue (morphine vs. heroin) Non-essential amino acids and potassium are actively pumped out of the BBB to keep the brain from firing uncontrollably Ineffective against fats, fatty acids, oxygen, CO2, alcohol, nicotine, anesthetics

44. Drain Bamage Traumatic injury Head injuries are the leading cause of accidental death in North America Not limited to only the point of impact Coup Injury occurs at the point of impact Contrecoup injuries occur at the opposite side, due to the brain bouncing off the inside of the skull

45. Drain Bamage Concussion: an alteration in brain function following a blow to the head Signs and symptoms Lethargy, loss of consciousness Dizziness/vertigo Asymmetrical pupil size (Anisocoria) Vomiting Confusion Loss of memory Ringing in the ears Alterations in smell and taste

46. Drain Bamage If you suspect someone has a concussion: Keep them awake Evaluate their mental state x3 Ask them if they know what day it is Ask them if they know their name Ask them if they know where they are If they can't answer these questions, seek medical attention immediately!

47. Drain Bamage If they vomit, keep them from choking on it Make sure they are attended for at LEAST 4 hours following the injury If you suspect they have an injury, even slight, seek medical attention promptly!

48. Drain Bamage Post-concussion syndrome An accumulation of brain damage from multiple concussions Can result in long-term impairment of cognitive function and personality disorders Often irreversible, but treatable

49. Drain Bamage CVA's/Strokes Occurs when circulation to the brain is blocked a part of brain tissue dies Most common cause of ischemia is a blood clot in the circle of Willis or branches of the carotid arteries Most survivors are typically paralyzed unilaterally (hemiplegia)

50. Drain Bamage Effective treatment of post-stroke patients: Physical therapy is the most important in preventing lasting difficulties and muscle wasting Chiropractic care can aid in establishing new cortical pathways through cortical bombardment of proprioception Aspirin is a good treatment to prevent another clot from forming, but can cause gastric ulcers Prescription Angiotensin Converting Enzyme inhibitors (ACE) may be prescribed to lower blood pressure