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
What is hyperventilation syndrome?
- hyperventilation causing respiratory alkalosis; underlying anxiety may provoke the hyperventilation
- symptoms reproduced with voluntary hyperventilation
What is an essential tremor (intention tremor)?
population: family history, autosomal dominant, elderly patients
- intention/action tremor: hands and head
- shaking occurs with simple tasks such as tying shoelaces, head writing, shaving or simply holding hands against gravity
- symptoms may be aggravated by stress, fatigue, caffeine, and temperature extremes
- better with alcohol
What is the tx for essential tremor?
- propranlol (first line) reduces limb tremor magnitude by ~50%
- primidone, alprazolam, small amounts of alcohol, gabapentin, topiramate, or nimodipine
- drug-resistant cases - deep brain stimulation
What are the characteristics of cluster headaches?
- unilateral, excruciating, sharp, searing, or piercing pain (often at night), lacrimation, and nasal congestion
- males > females
- tx with oxygen 100% at 6-12 L/min for 15 minutes via nonrebreathing mask proved relief within 15 minutes and imitrex
What is a migraine headache?
a headache of varying intensity, often unilateral, and accompanied by nausea and sensitivity to light and sound
What is the presentation of a migraine?
- teens, females > males
- pulsating, duration of 4-72 hours, unilateral, nausea, dialing associated with photophobia and photophobia
- without aura = most common, N/V, photophobia, phonophobia
- aura: scotoma, flashing lights, sound
- HA follows aura w/in 30 min; visual = MC
How is a migraine dx?
clinical
What is the tx for a migraine?
- abortive: triptans (do not use in ischemic heart disease), ergotamine (do not use in pregnant women)
- prophylaxis: atenolol, propranolol, verapamil or TCAs
What is a tension headache?
a tension-type headache is typically described as bilateral, mild to moderate, dull pain
What is the presentation of a tension headache?
bilateral, squeezing sensation, mild to moderate, dull pain
-whereas a migraine is typically pulsating, unilateral; and associated with nausea, vomiting, and photophobia or photophobia
What is the tx of a tension headache?
NSAIDs or muscle relaxer
What is Parkinson disease (resting tremor)?
caused by degeneration of basal ganglia in the substance migration leading to loss of dopamine-containing neurons located in the substantial migration and locus coeruleus
- age onset after 50 y/o
- meds that cause Parkinsonism: neuroleptics (chlorpromazine, metoclopramide, reserpine)
- Lewy bodies
- acetylcholine/dopamine imbalance
What are the three cardiac features of Parkinson disease?
rest (pill-rolling) tremor, cogwheel rigidity and bradykinesia (slowness of movement)
-other clinical features: Mask facies, loss of postural reflexes, decreased blink rate, shuffling gait, hypophonia, micrographic, gait arrest, and backward falling
How is the dx of Parkinson disease made?
based on clinical impression
- the gold standard for diagnosis is a neuropathologic exam
- MRI may be useful in evaluating the possibility of cerebrovascular disease, tumor, or multiple system atrophy as potential causes
What is the tx of Parkinson disease?
with dopamine agents
- < 65 dopamine agonists: bromocriptine, pramipexole, ropinirole
- directly stimulates dopamine receptors, fewer side effects than levodopa, used in younger patients to delay the use of levodopa
- > 65 Sinemet (levodopa/carbidopa)
- common side effects of L-dopa: gastrointestinal upset with nausea and vomiting, vivid dreams or nightmares, psychosis, and dyskinesias
What are the characteristics of focal seizures with retained awareness?
consciousness maintained
- this type of focal seizure was previously known as simple partial seizure
- no alternation in consciousness, abnormal movements or sensations
What are the characteristics of focal seizures with loss of awareness?
consciousness impaired
- this type of focal seizure may also be called a focal dyscognitive seizure (previously known as complex partial seizure)
- altered consciousness, automatisms (i.e lip-smacking)
- present with a poetical Tate (Confusion and loss of memory) which differentiated them from absence seziures
What is the tx of focal seizures?
phenytoin and carbamazepine are drugs of choice
What are generalized seizures?
occur when there is widespread seizure activity in the left and right hemispheres of the brain
-start midbrain or brainstem and spreads to both cortices
What are the characteristics of absence seizures?
formerly known as petit Mal
-characterized by a brief impairment of consciousness with an abrupt beginning and ending, at times involuntary movements may occur, but they are uncommon and the patient has no recollection and witnesses commonly miss them
What are the characteristics of a tonic-clonic?
convulsive seizures (formerly known as grand Mal)
- bilaterally symmetric and without focal onset
- begins with sudden loss of consciousness - a fall to the ground
- tonic phase: very stiff and rigid 10-60 seconds
- clonic phase: generalized convulsions and limb jerking
- postictal phase: a confused state
What is an atonic seizure?
also known as drop attacks
-looks like syncope, sudden loss of muscle tone
What is a clonic seizure?
during a clonic seizure, a person may lose control of bodily functions and begin jerking in various parts to the body, he/she may temporarily lose consciousness, followed by confusion
What is a tonic seizure?
extreme rigidity then immediate LOC, but not followed by a clonic phase
What is a myoclonic seizure?
muscle jerking, but not the tonic phase, occurs in the morning
What is a febrile seizure?
convulsion associated with an elevated temperature greater than 38, > 6 months < 5 years, absence of central nervous system infection or inflammation
What are infantile spasms?
infantile spams are a type of epilepsy seizure but they do not fit into the category of focal or generalized
What is psychogenic non-epileptic seizures (PNES)?
are not due to epilepsy but may look very similar to an epilepsy seziure
What is status epilepticus?
a single epileptic seizure lasting more than five minutes or two or more seizures within a five-minute period without the person returning to normal between them
- two forms: convulsive and non convulsive
- convulsive status epilepticus presents with a regular pattern of contraction and extension of the arms and legs
- nonconvulsive status epilepticus includes complex partial status epilepticus and absence status epilepticus
What is the tx for status epilepticus?
benzodiazepines (lorazepam) are the preferred initial treatment after which typically phenytoin is given
What is syncope?
refers to a transient loss of consciousness/postural tone secondary to an acute decrease in cerebral blood flow
-characterized by a rapid recovery of consciousness without resuscitation
What is cardiac syncope?
arrhythmias (e.g. AV block, sick sinus syndrome), obstruction of blood flow (e.g. aortic stenosis, hypertrophic cardiomyopathy), massive MI
What is vasovagal syncope?
(neurocardiogenic) most common cause
What is orthostatic hypotension?
defect in vasomotor reflexes, common in elderly, diabetics, patients taking certain medications (e.g diuretics, vasodilators)
What is cerebral vascular disease?
a rare cause of syncope
What are the other noncardiogenic causes of syncope?
include metabolic causes (e.g hypoglycemia, hyperventilation), hypovolemia (e.g hemorrhage), hypersensitivity (syncope precipitated by wearing a tight collar or turning the head), mechanical reduction of venous return (e.g Valsalva maneuver, postmicturition), and various mediations (beta-blockers, nitrates, anti arrhythmic agents)
What is a transient ischemic attack?
a transient episode of neurologic dysfunction due to focal brain, retinal, or spinal cord ischemia without acute infarction
- blockage in blood flow does not last long enough to cause permanent infection
- sudden onset of neurologic deficit, lasting minutes to < 1 hour (15-30 min on average), a reversal of symptoms within 24 h
What are the clinical manifestations of a transient ischemic attack?
- internal carotid artery: amaurosis fugax (monocular vision loss - temporary “lampshade down on one eye”) weakness in the contralateral hand
- ICA/MCA/ACA: cerebral hemisphere dysfunction, sudden headache, speech changes, confusion
- PCA: somatosensory deficits
- Vertebrobasilar: brainstem/cerebral symptoms (gait and proprioception)
How is a transient ischemic attack dx?
by CT (without contrast), MRI more sensitive, carotid doppler ultrasound to look for stenosis, CT angiography, MR angiography of the neck
- carotid endarterectomy if internal or common carotid artery stenosis > 70%
- aspirin within 24 hours, anti platelet therapy (e.g aspirin or clopidogrel or aspirin-dipyridamole) should be then initated
What is the tx of transient ischemic attack?
- hospital admission for new-onset and recurrent TIA, unless a confident diagnosis of the cause of the event can be made
- antiplatelet therapy: aspirin +/- dipyridamole OR clopidogrel
- not if high risk - warfarin should be used
- average 5% risk of recurrence per year
What is vertigo?
the sensation of movement (spinning, tumbling or falling) in the absence of actual movement or an over response to movement
-duration and presence of hearing loss or nystagmus can help with diagnosis and differentiation between central vertigo and peripheral vertigo
What are the characteristics of central vertigo?
- gradual onset, continuous, nausea or vomiting, vertical nystagmus, no auditory symptoms, motor, sensory, or cerebellar deficits
- Romberg sign
- etiology: brainstem vascular disease, arteriovenous malformation, multiple sclerosis, vertebrobasilar migraine, brain tumor, head injury, medications
What are the characteristics of peripheral vertigo?
inner ear
- sudden onset, intermittent, nausea/vomiting, hearing loss, nystagmus (horizontal with rotary component)
- etiology: labyrinthitis, benign paroxysmal positional vertigo, endolymphtic hydros (meniere syndrome), vestibular neuritis, and head injury
- dix hallpike
How is vertigo dx?
- dix-hallpike maneuver
- nonfatigable nystagmus = central cause
- audiometry, calori stimulation, ENG, MRI, evoked potentials
What is the tx of vertigo?
- peripheral - treat with Epley’s maneuver, vestibular suppressants help with acute symptoms: diazepam (valium), meclizine
- central - threat the source
