Neurology Flashcards
What is Alzheimer disease?
neurodegenerative disease (i.e. loss of neurons in the brain); beta-amyloid plaque, neurofibrillary tangle formation = impaired neuronal signaling, neuron apoptosis
What are the characteristics of Alzheimer disease?
- the most common form of dementia (66% of all cases)
- Alzheimer disease is the fourth most common cause of death in the United States
- prevalence increases with age - approximately 10% to 15% of individuals over age 65, and 15% to 30% of individuals over age 80
- begins insidiously and progresses at a steady rate
- progressive memory loss
- patients with Down syndrome often see an early onset of Alzheimer by age 40 due to the presence of APP gene on chromosome 21
What are the cognitive deficits of Alzheimer disease?
disorientation, language difficulties, inability to perform complex motor functions, inattention, visual misperception, poor problem solving, inappropriate social behavior, hallucination
What is the progression of Alzheimer?
short term memory loss (had for breakfast?) - loss of motor skills and language - long term memory loss (spouse’s name) - disoriented (risk getting lost) - bedridden - death (infection)
-average time from onset to death is 5 years
How is Alzheimer dx?
definitive diagnosis is by brain biopsy (after autopsy)
- Alzheimer’s ideas is essentially a clinical diagnosis; exclude other causes first, formal neuropsychological testing to confirm the diagnosis
- an intellectual decline in 2+ areas of cognition
- documented by MMSE or similar scale
- CT scan or MRI showing diffuse conical atrophy with enlargement of ventricles strengthens the diagnosis
- CBC, CMP, heavy metal, calcium, glucose, TSH, B12, renal, LFT, drug/ETOH levels
What is the tx for Alzheimer disease?
- no treatment found to have significant effects
- cholinesterase inhibitors (first line): donepezil, rivastigmine, galantamine - brains of patients with Alzheimer disease have lower levels of acetylcholine
- memantine (NMDA - receptor antagonist): mod-severe
- certain dietary supplements (ginkgo, lecithin) have not been proven to be beneficial
- avoid anticholinergics
What is Bell palsy?
hemifacial weakness/paralysis of muscles innervated by CN VII due to the swelling of the cranial nerve
What are the characteristics of Belly palsy?
- the prognosis is very good; 80% of patients recover fully within weeks to months
- cause is uncertain
- possible viral etiology (herpes simplex) - immunologic and ischemic factors implicated as weel
- upper respiratory infection is a common preceding event
- there is an acute onset of unilateral facial weakness/paralysis
- both upper and lower parts of the face are affected (differentiate quickly from stroke - can wrinkle forehead)
- diagnosis is clinical, but consider Lyme disease in endemic areas (do not use steroid if Lyme is suspected)
- consider EMG testing if paresis fails to resolve within 10 days
What is the tx of Bell palsy?
- usually, none is required, as most cases resolve in 1 month
- a short course of steroid therapy (prednisone) and acyclovir, if necessary
- patient should wear an eye patch at night to prevent corneal abrasion
- surgical decompression of CN VII is indicated if the paralysis progresses or if tests indicate deterioration
What is cerebral vascular accident?
there are two main types of cerebrovascular accident or stroke; an ischemic stroke is caused by a blockage; a hemorrhagic stroke is caused by the rupture of a blood vessel
What are the characteristics of a cerebral vascular accident?
Acute onset of focal neurologic deficits resulting from - diminished blood flow (ischemic stroke) or hemorrhage (hemorrhagic stroke)
- contralateral paralysis, motor function, right-sided symptoms = left side stroke, left sided symptoms = right-side strokes
- carotid/ophthalmic: amaurosis fugax (monocular blind)
- MCA: aphasia, neglect, hemiparesis, gaze preference, homonymous hemianopsia
- ACA: leg paresis, hemiplegia, urinary incontinence
- PCA: homonymous hemianopsia
- Basilar artery: coma, cranial nerve palsies, apnea, drop attach, vertigo
- lacunar infarcts occur in areas supplied by small perforating vessels and result from atherosclerosis, hypertension, and diabetes, silent, pure motor or sensory stroke, “Dysarthria-Clumsy hand syndrome”, ataxic hemiparesis
How are cerebral vascular accident dx?
CT without contract for acute presentation - important to diagnose as ischemic or hemorrhagic
Wha is the tx of cerebral vascular accident?
for occlusive disease treat with IV tPA if within 3-4.5 hours of symptom onset
- can consider intra-arterial thrombolysis in select patients (major MCA occlusion) up to 6 hours after onset of symptoms
- for embolic disease and hyper coagulable states give warfarin/aspirin once the hemorrhagic stroke has been rule out
- endarterectomy if carotid >70% occluded
What is delirium?
an acute cognitive dysfunction secondary to some underlying medical condition and is usually reversible
- acute and rapid deterioration in mental status (hours-days), a fluctuating level of awareness, disorientation
- visual hallucinations are the most common type experience by patients with delirium
- high-risk after surgery especially in those with heart disease or diabetes
- delirium, unlike dementia, is usually reversible
- fall precautions - patients with delirium are six more times likely to fall
- delirium is the most common presentation of altered mental status in the inpatient setting
- alcohol abuse, is the most common cause of delirium, specifically, delirium tremens
- delirium is a side effect of acute hyperthyroidism known as thyroid storm
What are the underlying organic cause of delirium?
UTI, pneumonia, metabolic changes, CVA, MI, TBI, medications (anticholinergics, benzodiazepines, opioids)
How is delirium dx?
- mental status examination (MMSE)
- labs (chemistry, B12/folate)
- LP in a febrile, delirious patient (cerebral edema)
What is the tx of delirium?
treat the cause of delirium (almost always reversible) and provide supportive care, including sedation when necessary
-haloperidol for agitation/psychosis supportive
What is neurocognitive disorders (previously known as dementia)?
described as those with a significant (major) or moderate (mild) impairment of cognition or memory that represents a marked deterioration from a previous level of function
- increasing age
- insidious onset, progressive
- preserved consciousness, rarely hallucinations present
- no tremor unless due to Parkinson disease
- typically irreversible
What are the characteristics of Alzheimer disease?
- most common type
- progressive cognitive decline; most common older than age 65 years
- loss of brain cells, beta-amyloid plaques, and neurofibrillary tangles
- physical exam: abnormal clock drawing test
- treatment: anti cholinesterase drugs (Tacrine, Donepezil)
What are the characteristics of Vascular disease?
- second most common type
- associated with arteriolosclerotic small vessel disease
- multi-infarct, usually correlated with a cerebrovascular event and/or cerebrovascular disease
- stepwise deterioration with periods of clinical plateaus
- may cause a sudden decline
- treatment: blood pressure control
What are the characteristics of frontotemporal lobar degeneration?
- language difficulties, personality changes, and behavioral disturbances
- personality changes precede memory changes
What are the characteristics of Lewy body disease?
- parkinsonian symptoms
- gradual, progressive decline in cognitive abilities
- hallucinations and delusions, gait difficulties, and falls
What is substance/medication use dementia?
related to medication or non-prescription drug use
What are the characteristics of HIV infection dementia?
- cognitive decline associated with HIV infection
- substantial memory deficits, impaired executive functioning, poor attention and concentration, mental slowing, and apathy
- cerebral atrophy is typically evident on brain imaging
What are the main categories of dizziness?
- vertigo: false sense of motion, possibly spinning sensation (45-54%)
- disequilibrium: off balance or wobbly (16%)
- presyncope: feeling of losing consciousness or blacking out ( up to 14%)
- lightheadedness: vague symptoms, possibly feeling disconnected with the environment (approximately 10%)
What is benign paroxysmal positional vertigo?
- loose otolith in semicircular canals a false sense of motion
- positive findings with Dix-Hallpike maneuver; episodic vertigo without hearing loss
What is Meniere disease?
- increased endolymphatic fluid in the inner ear
- episodic vertigo with hearing loss
What is orthostatic hypotension?
- drop in blood pressure on position change causing decreased blood flow to the brain, adverse effect of multiple medications
- systolic blood pressure decrease of 20 mmHg, diastolic blood pressure decrease of 10 mmHg, or pulse increase of 30 beats per minute
What is Parkinson disease?
- dysfunction in gait curing imbalance and falls
- shuffling gait with reduced arm swing and possible hesitation
What is peripheral neuropathy?
- decreased tactile response when walking causes patients to be unaware when feet touch the ground, leading to imbalance and falls
- decreased sensation in lower extremities, particularly the feet
