Nursing 3366 Pathologic Processes: Implications for NursingLecture Notes: Disorders of the Neurologic SystemObjectives /outcomes for this subject:1. the relationship between key aspects of normal neurological function and the pathophysiology involved in select neurologically-related conditions, including:- ophthalmic derangements such as cataracts, glaucoma, and macular degeneration.- alterations in homeostasis of the CNS, including:o principles of CPP & ICP; effect of increased ICP (IICP) & cerebral edemao general states of altered states of consciousness & mentation such as delirium & dementiao meningitiso seizures.o brain attack—ischemic, hemorrhagic.o migraineso Parkinson’so Alzheimer’so multiple sclerosis- alterations in homeostasis of the peripheral nervous system, including:o myasthenia gravis2. signs and symptoms and basic treatment modalities associated with above pathological conditions**********************************Outline:I. Disorders of the CNSA. Concepts of cerebral blood flow & alteration1. overview2. CPP—cerebral perfusion pressure 3. ICP— intracranial pressure B. Brain attack (stroke)1. overview2. ischemic brain attack3. hemorrhagic brain attack4. S&S of brain attack5. bringing it all together6. diagnosis & treatment C. Degenerative diseases of the brain1. Alzheimer’s disease2. Parkinson’s disease3. multiple sclerosisD. Miscellaneous CNS disorders 1. migraines2. seizures3. meningitisFor your amusement watch this video:http://www.youtube.com/watch?v=Li5nMsXg1LkII. Peripheral nervous system (PNS) disorders A. Overview1. main category--neuromuscular junction disorders2. normal A&P of neuromuscular junction3. abnormalitiesB. Myasthenia gravis1. patho2. S&S3. treatmentIII. Ophthalmologic problemsA. General terminology & info related to eye / vision problems1. mydriasis2. miosis3. diplopia4. nystagmus 5 papilledemaB. Specific disease processes of the eyes1. cataracts2. glaucoma3. age-related macular Part B NOT ON TESTHOME STUDY--will be on testPlease BE SURE to look over this A&Psection (IA) ahead of time, as it will only briefly be discussed in class & it is very important to understand. 1I. Disorders of the CNS: the brain A. Concepts of cerebral blood flow & alteration 1. overviewa. cerebral blood flow is normally maintained at rate that matches metabolicneeds of brain & keeps the cerebrum oxygenatedb maintenance of effective cerebral blood flow dependent on keeping 2 forces in balance: cerebral perfusion pressure (CPP--the pressure of blood going into brain) and intracranial pressure (ICP—the pressure in the intracranial cavity)2. CPP—cerebral perfusion pressure a. pressure required to get oxygenated blood into the brain to perfuse the cells of the brainb. if EITHER too low (as happens in hypovolemia, hypotension, etc) OR too high (ex— hypertension), the result is ineffective perfusionischemia to brain cellular hypoxia cell injury & death loss of cell membrane integrity water & other cell contents are released results in cerebral edema and increased ICP  further loss of effective perfusion.c. summary: if CPP is either too high OR too low, can lead to cerebral edema and increased ICP3. ICP— intracranial pressure a. ICP is the totality of pressures in the brain—arterial pressures plus venous pressures plus CSF pressures, etcb. because the cranium is a bony structure, very little increase in pressure inthe brain, can be tolerated—“no place to go”—and some degree of pathologic alteration in brain function (e.g., decreased LOC, impaired sensorimotor function, etc) can be expected from even small amount of increased ICP (______).c. the main culprit in causing IICP & the loss of balance between ICP & CPP iscerebral edema; ex: ischemia from a blockage (plaque or stricture) of an artery in brain or going into brain (ex—carotid)  cells become hypoxic swell, increased vascular permeability edema increased ICP decreased CPP further brain ischemiad. same “scenario” can be applied to many situations: brain tumors, injuries,aneurysms, irritants like infections & acidosis, direct hypoxiaall ultimately lead to cerebral edema & IICP (these two almost always go “hand in hand”).FYI: Some numbers to give you perspective: Normal ICP: 10–15 mmHg (this is usually measured by an ICP monitoring device that is placed in the ventricles of the brain). Normal CPP: 60 – 150 mmHg. CPP is the pressure needed to adequately get blood into brain—depends on BP & ICP; formula for CPP: mean arterial pressure (MAP) – ICP. Ex: MAP: a BP of 120/80 = a MAP of ~93mm Hg, so someone with a 93 MAP & an ICP of 15 would have a CPP of 78mmHg (93mm Hg -15mm Hg), which is normal. Clinical application: if someone was in ICU with a head injury or stroke or other cause of increased cerebral edema and !CP, we would monitor these numbers and make treatment adjustments to keep them in the ranges that are most effective in getting perfusion to the brain.STUDY 1A AHEAD OF TIME—WON’T BE DISCUSSED IN CLASS BUT IMPORTANT TO UNDERSTAND.2B. Brain attack 1. overviewa. definition of brain attack --the process of any interruption of the normal blood supply to a part of the brain or the entire brain, resulting in damaged brain tissue. b. brain attacks were more commonly called “strokes” or “CVAs” (cerebrovascular accidents) but in recent years, “brain attack” is favored as best terminology to convey to lay people that they need to seek help as quickly as they would if having a heart attack. c. most common underlying etiologies of brain attack (BA) are:1) atherosclerosis of cerebral arteries (within the brain) and/or of incoming arteries (carotids & vertebral arteries). 2) HTN 3) “other”—includes issues like heart problems, which can lead to not enough cardiac output of blood to brain, & brain aneurysms.d. thus the risk factors for BA are same for all atherosclerotic disorders & include:1) preexisting hx of atherosclerosis in any part of body 2) preexisting hx of HTN3) older age (most strokes occur in pts over 65, though 28% occur in younger)4) family history5) diabetes (pts w/ DM are 3 times more likely to have strokes)6) lifestyle issues such as smoking (increases risk by 50%) and high-fatdietse. the two main, broad categories of BA are based on underlying mechanism-- ischemic cause and hemorrhagic cause (more on these below); some important general