neurology part i

Monro-Kellie doctrine

b/c of limited space for expansion, an increase in any one of the 3 components (blood, brain tissue, CSF) will cause a change in the volume of the others

normal ICP

5-15 mmHg

cerebral edema

abnormal accumulation of water or fluid in the intracellular or extracellular space that is associated w/ increase in volume of brain tissue; leads to autoregulation & other compensatory measures

cerebral response to increased ICP

brain can maintain steady perfusion pressure if aterial systolic is 50-150 mmHg & ICP is <40 mmHg

cushing’s resonse

w/ significant cerebral blood flow decrease; vasomotor center triggers an increase in arterial pressure in effort to overcome increased ICP; sympathetically mediated response causes increase in SBP w/ widening of pulse pressure & cardiac slowing

cushing’s triad

decreased HR; irregular respiration; widened pulse pressure

other s/s of increased ICP

weakness, lethargy, HA, vomiting, blurred vision, changes in behavior

increased ICP tx

• IV mannitol

• hyperventilation

• elevation of head

• draining extra fluid

• craniotomy

increased ICP causes

head injury, bleeding in brain, tumors, infections, extra fluid in brain, stroke

increased ICP assessment & dx

• usually CT or MRI; can also do PET or doppler

• no lumbar puncture due to risk of herniation

increased ICP complications

brain stem herniation, DI, SIADH

increased ICP monitoring

ventriculostomy, subarachnoid bolt, epidural or subdural catheter or fiberoptic transducer

alzheimer’s medical management

help maintain mental fx & manage cognitive & behavioral symptoms; meds like cholinesterase inhibitors can help w/ uptake of acetylcholine in brain, thus improving memory skills, tx as long as possible

seizure

sudden, uncontrolled d/c of electrical activity from brain

seizure manifestations

shaking, loss of bladder &/or bowel, LOC

epilepsy

2 or more szs, unprovoked sz activity

seizure risk factors

genetrics, acute febrile state, head trauma, cerebral edema, stopping sz meds, infections, toxin exposure, increased ICP, tumor, withdrawal

status epilepticus

sz lasting longer than 5 min or 2 or more szs w/out full recovery (THIS IS AN EMERGENCY)

tonic sz

sudden stiffening, LOC, autonomic changes; breathing can stop; 30 sec to several mins in duration

clonic sz

rhythmic jerking motions; several mins in duration; stiffening & relaxing; breathing irregular

tonic-clonic sz

first tonic, then clonic; LOC, loss of breathing, then irregular breathing; loss of bladder/bowel fx possible; post ictal phase longer

myoclonic sz

brief nonrhythmic jerking movements of extremities; singly or in groups; lasts ses

atonic or akinetic sz

sudden loss of muscle tone; causes falls; confused state afterward

complex partial sz

syncope/blackout for several mins, unaware movements, preceded & proceeded by amnesia

simple partial sz

no syncope/blackout, deja vu feeling, autonomic changes (flushing, HR), unilateral movement

sz medical interventions

• will need MRI to rule out lesions & EEG to detect abnormal electrical SPECT to identify the area in brain of abnormal activity

• driving restrictions & safety measure in home, possible support animal, identifying bracelet

• will need meds; pts can have breakthrough szs if meds are not at therapeutic lvl

• may need surgery, vagal nerve stimulator which delivers electrical stimulus to brain to control/reduce sz activity

ischemic stroke causes

• large artery thrombosis

• small penetrating artery thrombosis

• cardiogenic embolus

• cryptogenic (no known cause)

ischemic stroke symptoms

numbness or weakness of face, arm, or lef, esp on one side of body, aphasia, vision loss

hemorrhagic stroke causes

• intracerebral hemorrhage

• subarachnoid hemorrhage

• cerebral aneurysm

• arteriovenous malformation

hemorrhagic stroke symptoms

• worst HA of their life

• decreased LOC

• sz

TIA

sudden temporary loss of motor, sensory, or visual fx; 3-15% have CVA in next 90 days

stroke risk factors

meds, obesity, stress, heart disease, diabetes, physical inactivity, HTN, ETOH, high blood cholesterol, smoking

ischemic stroke medical management

antiplatelet therapy, DOAC, statins, ACE/diuretics or combo, endovascular therapy

t-pa

can be given during procedure, like thrombectomy in higher concentrations; allows for window of admin to open to 24 hrs

endovascular therapy

now recommendation that pts w/ acute ischemic stroke receive this & med management w/ a stent retriever if criteria is met

thrombolytic therapy

t-pa binds fibrin & converting plasminogen to plasmin which stimulates fibrinolysis of clot

hemorrhagic stroke assessment/dx

CT or MRI; cerebral angiography or CT angiography confirms dx

hemorrhagic stroke complications

cerebral hypoxia & decreased blood flow

vasospasm

usually occurs 7-8 days after initial hemorrhage; clot lyses & a rebleed can occur, often preceded by worsening HA, decrease LOC & a new focal deficit

primary head injury

occurs as consequence of direct contact to head/brain during instant of initial injury

secondary head injury

• develops over ensuing hours & days after initial injury

• results in adequate delivery of glucose & oxygen to cells

TBI

• trauma to skull, scalp, or brain

• 2x common in males

• high potential for poor outcome

• most common causes are falls & MVAs

• deaths usually occur at 3 points after injury

  • immediately

  • w/in 2 hours

  • 3 weeks

head injury manifestations

depend on locations & severity; persistent localized pain usually indicates fracture

battle sign

ecchymosis over mastoid area

head injury dx

non contrast CT, may need MRI

head injury med management

non-depressed skull fractures are usually observation w/ strict return precautions; depressed skull fractures are in OR w/in 24 hrs depending on severity & involvement in repair

contusion

bruised & damaged, severity depends on location but is usually frontal or temporal; actual impact of brain against the skulls causes the injury; symptoms usually peak in 18-36 hrs

epidural brain injury

symptoms can be delayed until you actually compress an area large enough to affect or cause distortion; usually caused by a rupture of the middle meningeal artery caused by a skull fracture; there is usually a brief LOC followed by a period of lucidity, then you get abrupt restlessness, agitated or confusion due to slight shift in ICP; then there is rapid deterioration that progresses to coma

subdural hematoma

small area btwn dura & brain that is usually reserved for a small amount of fluid; most common cause is trauma (fall), usually venous in nature; s/s usually hemiparesis, pupillary changes & changes in LOC; coma & cushing’s can signify rapidly expanding

chronic SH

can be a minor trauma, then the time btwn that & onset of symptoms can be lengthy; pt may actually forget initial injury/incident; symptoms can include severe HA, personality changes, mental deterioration, & focal sz; can look like a stroke

intracerebral hemorrhage & hematoma

usually from area of small, missile like

concussion

temporary loss of neurological fx w/ no apparent structural damage of the damage; frontal gets bizarre irrational behavior, temporal can produce temp amnesia & disorientation; duration of symptoms is indicator of grade of concussion

diffuse axonal injury

widespread shearing & rotational forces that produces damage throughout brain, usually associated w/ prolonged traumatic coma, no lucid moment, immediate coma, posturing, & global cerebral edema

meningitis

inflammation of meninges; can be viral, bacterial

meningitis risk factors

first year college students, military, smokers & viral upper respiratory infections, otitis media & mastoiditis

meningitis manifestations

HA, fever, chills, nuchal rigidity, photophobia, Kernig & Brudzinski signs, rash

meningitis med managements

• timely admin of antibiotics

• dexamethasone

• IVF for hydration & possible sz meds if needed

kernig

flex pt at knee & hip & then straighten knee; pain=positive

brudzinski

as you flex neck, you may get pt to bend at hips &/or knees

herpes simplex virus encephalitis

inflammatory process of brain

HSV encephalitis manifestations

fever, HA, confusion & hallucinations

HSV encephalitis med managemenet

acyclovir

multiple sclerosis

autoimmune attack on myelin that results in nerve impulse transmission defects, irreversible & progressive damage

multiple sclerosis manifestations

• unilateral optic neuritis, focal symptoms or partial myopathies

• fatigue, depression, weakness, numbness, difficulty in coordination, loss of balance, spasticity, & pain

• bowel, bladder, & sexual dysfunction; complications can include UTIs, constipation, pneumonia, osteoporosis, pressure injury, dependent pedal edema, contracture deformities

MS med

RRMS

myasthenia gravis

affects myoneural junction, characterized by varying degrees of weakness of voluntary muscles

MG manifestations

• only eye muscles are involved, diplopia & ptosis

• weakness of muscles in face & throat, limbs, & respiratory weakness

• decreased vital capacity & respiratory failure

MG dx

acetylcholinesterase inhibitor test, ice test

MG med management

anticholinesterase medications & immunosuppressive therapy, IVIG, therapeutic plasma exchange, & thymectomy

MG crisis

may need respiratory support, from CPT to intubation

guillian-barre

acute idiopathic polyneuritis is an autoimmune attack on peripheral nerve myelin

GB manifestations

begins w/ muscle weakness & diminished reflexes of lower extremities; hyoreflexia & weakness can lead to tetraplegia; nerves that innervate diaphragm & intercostal muscles can be affected leading to neuromuscular respiratory failure

GB risk factors

possibly autoimmune, association w/ immunizations, mild respiratory or intestinal infection

parkinson’s manifestations

tremor, rigidity, bradykinesia, postural instability

parkinson’s dx

presence of 2 or more cardinal manifestations; confirmed by positive response to levodopa trial

huntington

chronic, progressive, hereditary dz of nervous system

HD manifestations

motor dysfunction, cognitive impairment, behavioral features

HD meds

tetrabenazine

ALS manifestations

fatigue, progressive muscle weakness, cramps & fasciculations & lack of coordination

ALS meds

riluzole & edaravone