Neurology Flashcards
What is Lewy Body Dementia?
Dementia + >2 of the following: visual hallucinations, Parkinsonism, fluctuating cognition, and REM sleep behavior disorder; cognitive symptoms may precede or appear along with parkinsonian features; repeated falls and sleep disturbance are characteristic
Cognitive impairment would develop in this condition before or at the same time as Parkinsonism, not years later
Characterized by fluctuating cognition w/ pronounced variations in attention and alertness and bizarre visual hallucinations that are well formed and detailed
Cognitive decline, then Parkinsonism with severe sensitivity to potent dopamine antagonists
Micro: eosinophilic intracytoplasmic inclusion representing accumulation of alpha synuclein protein
Tx: carbidopa-levodopa for parkinsonism, cholinesterase inhibitors for cognitive impairment, 2nd generation antipyschotics if symptoms persist
What is Frontotemporal dementia?
Characterized by early personality changes (e.g., euphoria, disinhibition, apathy), compulsive behaviors (e.g., peculiar eating habits, hyper-orality) and impaired memory; behavioral changes precede memory impairment
Presents around ag 60, autosomal dominant, progresses rapidly compared to AZ
Tau proteins, Pick bodies
Visual-spatial functions usually remain intact
Frontotemporal atrophy on neuroimaging
Manifests around age 60, demonstrably early than AD
What is Myasthenia gravis?
Autoantibody-mediated degradation of Ach receptors at neuromuscular junction
Epidemiology: women - 2nd to 3rd decade, men - 6th to 8th decade
Involved site: Ach receptor in postsynaptic membrane
Features: fluctuating and fatigable muscle weakness that is worse later in the day - ocular (ptosis, diplopia), bulbar (dysphagia, dysarthria), facial, neck and limb muscles; respiratory muscles (myasthenic crisis)
Causes of exacerbation: medication (abx-fluoroquinolones, aminoglycosides; anesthetics-neuromuscular blocking agents; cardiac meds-beta blockers, procainamide; other-MgSulfate, penicillamine; tapering of immunosuppressive meds) pregnancy/childbirth; surgery (especially thymectomy); infection
Dx: bedside- edrophonium (tensilon) test, ice pack test (cold temp improves muscle strength by inhibiting breakdown of Ach at NMJ); Ach receptor antibodies (highly specific), CT scan of chest to evaluate for thymoma
Tx: AchE inhibitors (eg pyridostigmine), +/- immunotherapy (eg corticosteroids, azathioprine), thymectomy
Ptosis only. pupillary response is spared.
What is Lambert-Eaton syndrome?
Approx. 50% of cases are assoc. w/ an underlying malignancy, mostly small cell lung cancer
Involved site: presynaptic membrane voltage-gated calcium channels
Features: proximal muscle weakness (eg standing from a chair, combing hair, putting dishes in overhead cabinets), autonomic dysfunction (eg dry mouth), cranial nerve involvement (eg ptosis), diminished or absent deep-tendon reflexes
Tx: guanidine or 3,4-diaminopyridine to increase presynaptic Ach levels; refractory - IV Ig or oral immunosuppressants (eg corticosteroids, azathioprine)
What is dermatomyositis/polymyositis?
Involved site: muscle fiber injury
Features: symmetrical and more proximal muscle weakness; interstitial lung disease, esophageal dysmotility, Raynaud phenomenon; polyarthritis; skin findings (eg gottron papules, heliotrope rash) in dermatomyositis
Preserved reflexes, elevated muscle enzymes (eg creatine kinase)
What is a CT with contrast?
Useful in identifying structural abnormality or mass lesions (eg primary or metastatic cancer, abscess, infarct)
Not helpful for identifying intracranial hemorrhage.
What is a glucocorticoid-induced myopathy?
Complication of chronic corticosteroid use
Presentation: muscle atrophy and painless proximal muscle weakness, which is more prominent in the LE
No muscle inflammation or tenderness
Normal CK and ESR
Improves when offending med is discontinued
What is polymyalgia rheumatica?
Muscle pain and stiffness in shoulder and pelvic girdle; normal muscle strength
Tenderness w/ decreased ROM at shoulder, neck and hip
Responds rapidly to glucocorticoids
Normal CK
Elevated ESR
What is cerebral palsy?
Non-progressive motor dysfunction
RF: Prematurity*, low birth weight; premature infants are more likely to have periventricular leukomalacia (white matter necrosis from ischemia/infection) and intraventricular hemorrhage (germinal matrix bleeding due to fragile vasculature and unstable cerebral blood flow) assoc. w/ CP
Presentation: delayed motor milestones, hypertonia, hyperreflexia; comorbid seizures, intellectual disability; equinovarus deformity (feet point down and inward); commando crawl (commonly seen in CP due to contractures of the lower limbs)
Dx: MRI of brain, +/- EEG, +/- genetic/metabolic testing
Mgmt: physical, occupational, speech therapies; nutritional support, antispastic medications
What is acute angle closure glaucoma?
Due to sudden narrowing or closure of the anterior angle chamber
Typically occurs as a response to pupillary dilation from meds (eg anticholinergics such as tolterodine, trihexyphenidyl; sympathomimetics, and decongestants) or other stimuli (eg dim light)
Anticholinergics cause mydriasis, which may precipitate acute ACG
More common in women (esp >40yo), Asian and Inuit populations, individuals with farsightedness
Presentation: rapid onset of severe eye pain, halos around lights; affected eye will appear injected, pupil will be dilated and poorly responsive to light; tearing and headache w/ subsequent nausea and vomiting as IOP increases
Untreated acute ACG can lead to severe and permanent vision loss w/in 2-5h of symptom onset
What is Guillain-Barré syndrome?
Pathophys: immune-mediated demyelinating polyneuropathy of peripheral nerve fibers, preceding GI (campylobacter) or respiratory infection Presentation: paresthesia, neuropathic pain; symmetric, ascending weakness; decreased/absent deep-tendon reflexes; autonomic dysfunction (eg arrhythmia, ileus, orthostatic hypotension, urinary retention, lack of sweating); respiratory compromise Bulbar sxs (dysarthria) Dx: clinical; supportive findings (CSF fluid: albuminocytologic dissociation = increased protein, NORMAL WBCs; abnormal electromyography and nerve conduction) Mgmt: monitor autonomic and respiratory function; IV Ig or plasmapheresis
What is CSF analysis normally?
OP: 100-180/200-300 mm H2O (8-15mm Hg)
WBC 0-5
Glucose 40-70
Protein <40
What is CSF analysis in bacterial meningitis?
WBC >1000 (PMNs)
Glucose <40
Protein >250
What is CSF analysis in tuberculous meningitis?
Similar to bacterial CSF findings:
WBC 100-500
Glucose <45
Protein 100-500
What is CSF analysis in viral meningitis?
WBC 10-500
Glucose 40-70
Protein <150 (Normal to high)
What is CSF analysis in GBS?
WBC 0-5
Glucose 40-70
Protein 45-1000
What is Lesch-Nyhan syndrome?
Pathophys: X-linked recessive, deficiency of hypoxanthine-guanine phophoribosyltransferase, hypoxanthine and uric acid accumulation
Presentation: delayed milestones and hypotonia in infancy; early childhood - intellectual disability, extrapyramidal sxs (dystonia, chorea), pyramidal sxs (spasticity, hyperreflexia), self-mutilation; biting fingers and tongue, writhing movements, neprholithiasis; gouty arthritis in late, untreated disease
What is subclavian steal syndrome?
Due to stenosis or occlusion of proximal subclavian artery, leading to reversal of blood flow in ipsilateral vertebral artery
Pts are often asymptomatic but may have sxs of upper extremity ischemia (eg pain, fatigue, paresthesias) or vertebrobasilar insufficiency (eg dizziness, ataxia, dysequilibrium) that are worsened by upper extremity exercise
Lower brachial SBP (>15mm Hg) in affected arm, systolic bruit in supraclavicular fossa on affected side
4th heart sound may be present due to LVH from systolic HTN
What is cavernous sinus thrombosis?
B/c facial/ophthalmic venous system is valveless, uncontrolled infection of the skin, sinuses, and orbit can spread to the cavernous sinus
Headache = most common symptom; low grade fever and periorbital edema usually occur several days later secondary to impaired venous flow in the orbital veins
Vomiting = result of intracranial HTN and fundoscopy may reveal papilledema
Unilateral sxs of HA, binocular palsies, periorbital edema, hypoesthesia, or hyperesthesia can rapidly become bilateral b/c CN 3, 4, 5.1, 6 pass through cavernous sinus
What is Sturge Weber syndrome?
Neurocutaneous disorder characterized by capillary malformation in CN 5.1, 2 distribution
Pathophys: mutation in GNAQ gene
Presentation: Port wine stain (CN 5.1, 2 distribution), leptomeningeal capillary-venous malformation, seizures +/- hemiparesis, intellectual disability, visual field defects, glaucoma (common)
Dx: MRI of brain w/ contrast
Mgmt: laser therapy to reduce appearance of port wine stain, antiepileptic drugs, IOP reduction
What is infant botulism?
Pathogenesis: ingestion of c. botulinum spores from environmental dust
Highest in California, Utah, and Pennsylvania
Ingestion of raw honey is also a risk factor
Presentation: descending flaccid paralysis; bulbar palsies (ptosis, sluggish pupillary response to light, poor suck and gag reflexes), constipation and drooling
Treatment: human-derived botulism immune globulin
What is foodborne botulism?
Pathogenesis: ingestion of preformed c. botulinum toxin
Presentation: descending flaccid paralysis
Treatment: equine-derived botulism antitoxin
What is CNS lymphoma in an HIV patient?
Presence of EBV DNA in the CSF is specific for this condition
Dx: MRI reveals a weakly ring-enhancing mass that is usually solitary and periventricular
What is psychogenic nonepileptic seizure?
A type of conversion disorder commonly misdiagnosed as a seizure disorder.
Presentation: forceful eye closure, side to side head or body movements, rapid alerting or reorienting, memory recall of the event, lack of post-ictal confusion
Not assoc. w/ abnormal cortical activity
Dx: video-EEG (gold standard) demonstrating lack of epileptiform activity
What is antiplatelet/antithrombotic therapy for ischemic stroke?
Presentation w/in 3-4.5h of symptom onset = IV alteplase (tPa) Stroke w/ no prior antiplatelet therapy = aspirin Stroke on aspirin therapy = aspirin + dipyramidole OR clopidogrel Stroke w/ evidence of atrial fibrillation = long term anticoagulation (eg warfarin, dabigatran, rivaroxabn) Stroke w/ larger anterior circulation artery occlusion w/in 24h of sxs onset = Mechanical thrombectomy (regardless if pt received alteplase), then aspirin Pt w/ intracranial large-artery atherosclerosis = Aspirin + clopidrogrel for 90d, then aspirin
What is the criteria for thrombolytics in stroke?
Inclusion: ischemic stroke w/ measurable neurodeficits; sxs onset <3-4.5h before tx initiation
Strict exclusion criteria: hemorrhage or multilobar infarct involving >33% of cerebral hemisphere on CT scan, stroke/head trauma in past 3mo, hx of intracranial hemorrhage/neoplasm/vascular malformation, recent intracranial/spinal injury, active bleeding or arterial puncture in past 7d at non-compressible site, BP >185/100, platelets <100k or glucose <50, anticoagulant use with INR >1.7, PT >15s or increased active PTT
Relative exclusion: minor or rapidly improving neurodeficits, major surgery/trauma in past 14d, myocardial infarction in past 3mo, GU or GI bleeding in past 21d, seizure or stroke onset, pregnancy
What is duchenne muscular dystrophy?
X linked recessive deletion of dystrophin gene on chXp21
Presentation: onset at 2-3y; progressive weakness, Gower maneuver, calf pseudohypertrophy
Comorbidities: scoliosis, cardiomyopathy
Prognosis: wheelchair-dependent by adolescence, death by age 20-30 from respiratory or heart failure
What is Becker muscular dystrophy?
X linked recessive deletion of dystrophin gene on chXp21
Presentation: onset age 5-15y; milder weakness compared to duchenne’s
Comorbidities: cardiomyopathy
Prognosis: death by age 40-50 from heart failure
What is myotonic muscular dystrophy?
AD expansion of a CTG trinucleotide repeat in DMPK gene on ch19q13.3
Presentation: onset age 12-30y; facial weakness, hand grip myotonia, dysphagia
Comorbidities: arrhythmias, cataracts, balding, testicular atrophy/infertility
Prognosis: death from respiratory failure or heart failure depending on age of onset
What is a lacunar stroke?
Etiology: small penetrating artery occlusion (via thrombus) due to hypertensive arteriolar sclerosis and lipohyalinosis
Infarcts are quite small
Affected areas: basal ganglia, subcortical white matter (eg internal capsule, corona radiata), pons, cerebellum
RF: HTN*, DM, advanced age, increased LDL, smoking
Presentation: absence of cortical signs (aphasia, agnosia, neglect, apraxia, hemianopia, urinary incontinence), seizure, or mental status changes; common syndromes - pure motor hemiparesis (most frequent; from stroke in posterior limb of internal capsule), pure sensory stroke, ataxic hemiparesis, dysarthria-clumsy hand
The face, arm, and leg are all equally affected.
Imaging: due to small size, not appreciated well on noncon CT scans shortly after event
[small, dont cause rapidly worsening global neuro sxs (eg vomiting, stupor, bradycardia)]
What is Wernicke-Korsakoff Syndrome?
Assoc. conditions: chronic alcoholism (most common), malnutrition (anorexia nervosa, short gut syndrome - Crohn’s), hyperemesis gravidarum
Pathophys: thiamine deficiency
Presentation: confusion, encephalopathy, oculomotor dysfunction (eg horizontal nystagmus, bilateral abducens palsy), postural and gait ataxia; malnourishment
Treatment: IV thiamine followed by or along with glucose infusion
What is exertional heat stroke?
Heat exhaustion: due to inadequate fluid and salt replacement and body is unable to maintain adequate CO. CNS dysfunction (AMS) is not present.
Due to thermoregulation failure
RF: strenuous activity during hot and humid weather, dehydration, poor acclimatization, lack of physical fitness, obesity, meds (anticholinergics, antihistamines, phenothiazines, tricyclis)
Presentation: core temp >40C (104F) immediately after collapse AND CNS dysfunction (altered mental status, confusion, irritability, seizure), additional organ or tissue damage (renal/hepatic failure, disseminated intravascular coagulation - persistent bleeding (nose bleed), acute respiratory distress syndrome)
Mgmt: rapid cooling (ice water immersion preferred; can consider high flow cool water dousing, ice/wet towel rotation, evaporative cooling; fluid resuscitation, electrolyte correction, mgmt of end-organ complications, no role for antipyretic therapy
What is alcoholic cerebellar degeneration?
Epi: >10 years of heavy alcohol use, degeneration of Purkinje cells (cerebellar vermis)
Presentation: usually develops over weeks to months, wide based gait, in-coordination in legs, cognition usually intact
Dx: Clinical - impaired tandem walking/heel knee shin, preserved finger-nose testing;
Imaging: CT/MRI - cerebellar atrophy
Treatment: alcohol cessation, nutritional supplements, ambulatory assistance devices (walker)
What is pain management for cancer?
Mild: nonopioids (acetaminophen, NSAIDs)
Moderate: weak opioids +/- nonopioids (codeine, hydrocodone, tramadol)
Severe: strong short-acting opioids (morphine, hydromorphone) –> calculate total daily dose and convert to long-acting formulation (fentanyl patch, oxycodone) PLUS short-acting opioids for breakthrough pain
What is fetal alcohol syndrome?
Face: smooth philtrum, thin vermillion border, small palpebral fissures, microcephaly
Growth is compromised with percentiles <10th for age and sex
Social withdrawal and delays in motor and language milestones
What is down syndrome?
Most common genetic cause of developmental delay
Meiotic nondisjunction of chromosome 21
Face: flat facial profile, slanted palpebral fissures, small low-set ears
Body: excessive skin at nape of neck, single transverse palmar crease, clinodactyly, large space between the first 2 toes
What is Fragile X syndrome?
Caused by trinucelotide (CGG) repeat expansion in fragile X mental retardation (FMR1) gene
Most common X-linked inherited cause of intellectual disability
Speech and motor delays, begin walking and talking around 20mo instead of at 12mo; ADHD and Autism spectrum disorder are also common
Face: long narrow face, prominent forehead and chin, large ears, macrocephaly
Body: macroorchidism (large testicles)
What is hypokalemia?
Causes: K-wasting diuretics, diarrhea, vomiting, anorexia, hyperaldosteronism
Presentation: weakness, fatigue, muscle cramps; flaccid paralysis, hyporeflexia, tetany, rhabdomyolysis, arrhythmias
Dx: ECG - broad flat T waves, U waves, ST depression, premature ventricular beats
What is Parkinson’s disease dementia?
Characterized by executive and visuospatial dysfunction (impaired attention and planning, inability to recognize familiar people, getting lost in familiar locations)
Dx: when Parkinsonism predates cognitive impairment by >1 year; PD then dementia = PDD
What are the clinical features of Alzheimer disease?
Most common cause of dementia in the western world.
RF: old age, female sex, family history, head trauma, and Down syndrome
Typical first symptoms: memory loss for recent events, language difficulties, and apraxia, followed by impaired judgement and personality changes
Early findings: anterograde memory loss* (immediate recall affected, distant memories preserved), visuospatial deficits (eg lost in own neighborhood), language difficulties (eg difficulty finding words), cognitive impairment w/ progressive decline
Late findings: neuropsychiatric (hallucinations, wandering, delusions, paranoia), personality changes (apathy, agitation), dyspraxia (difficulty performing learned motor tasks), lack of insight regarding deficits, noncognitive neurologic deficits (pyramidal and extrapyramidal motor, myoclonus, seizures), urinary incontinence
Imaging: generalized cortical atrophy; reduced hippocampal volume or medial temporal lobe atrophy may be seen in temporal lobe*
What is phenytoin toxicity?
Normal serum levels: 10-20, increase by 10% at a time; zero-order elimination
Acute toxicity manifests with cerebellar dysfunction: horizontal nystagmus (nystagmus on lateral gaze), ataxia (wide based gait), dysmetria (on finger to nose testing), slurred speech, n/v, and hyperreflexia
Severe toxicity: altered mental status (lethargy, confusion), coma, paradoxical seizures, death
Bactrim, fluconzaole inhibit cyp450 system and can increase the drug’s concentration
Valproic acid can displace phenytoin from plasma proteins and increase concentration of drug
What is brain death?
Irreversible cessation of brain activities
Absence of cortical and brain stem functions/reflexes (pupillary light reflex, oculovestibular reflex)
Heart rate fails to accelerate after atropine injection b/c vagal control of heart is lost
Apnea test: no spontaneous respiration at PCo2 of >50
Clinical diagnosis; spinal cord may still be functioning, therefore deep tendon reflexes (DTRs) may be present
What is status epilepticus?
Seizure lasting >/= 5 minutes or >/= 2 seizure events in which patient does not completely regain consciousness in between episodes
Increased risk of developing permanent injury due to excitatory cytotoxicity
Cortical laminar necrosis is the hallmark of prolonged seizures and can lead to persistent neurologic deficits and recurrent seizures
Tx: IV benzodiazepine (lorazepam, diazepam), + non-benzodiazepine (fosphenytoin, phenytoin, levetiracetam, or valproic acid) to prevent seizure recurrence
What is Bell’s Palsy?
Etiology: reactivation of neurotrophic virus (most commonly HSV), infection causes inflammation and edema of facial nerve resulting in nerve compression and degeneration of myelin sheath
Peripheral neuropathy involving CN7; sxs onset is acute (over the course of hours) and progressive
May be preceded by prodrome of auricular pain or dysacusis (distortion of sound)
Unilateral facial paralysis: mouth drooping, disappearance of nasolabial fold, involvement of upper face, decreased ipsilateral eye lacrimation, hyperacusis, decreased sensation of taste over anterior 2/3 of ipsilateral tongue
Tx: oral glucocorticosteroids; valacyclovir or acyclovir may speed time to complete recovery of facial function and b/c of assoc. with HSV
Partial or complete recovery occurs w/in 3-4 months
What is a focal seizure?
Etiology: structural abnormality (eg tumor), genetic epilepsy, unknown
Presentation: origin - one cerebral hemisphere, intact (simple) or impaired (complex) awareness, +/- secondary generalization which can cause impaired consciousness; can involve motor (head turning, arm twitching), sensory (paresthesias), and autonomic (eg sweating)
Following episode, postictal confusion and lethargy are common, and transient postictal paresis or paralysis (Todd paralysis) may also occur
Not provoked by hyperventilation
Dx: MRI of the brain, EEG
What is tick paralysis?
Characterized by rapidly progressive ascending paralysis (over hours to days) which may be asymmetrical, paresthesias in the LEs
Absence of fever and sensory abnormalities, normal CSF examination, no autonomic dysfunction
Etiology of paralysis: neurotoxin; tick needs to feed for 4-7d for release of neurotoxin
Tx: meticulous search for tick; removal results in improvement w/in 1h and complete recovery after several days
What is cervical artery dissection?
Mechanism: penetrating trauma/neck strain/manipulation, fall with object in mouth (toothbrush, pencil), neck manipulation (eg yoga, sports)
Internal carotid artery is located directly behind lateral and posterior to the tonsillar pillars; injury leads to dissection or thrombus formation
Presentation: gradual-onset hemiplegia, aphasia, neck pain, “thunderclap” headache, facial droop
Dx: CT or MR angiography
What is lead poisoning?
RF: occupational exposure (eg lead paint, batteries, ammunition, construction)
Presentation: GI (abdominal pain, constipation, anorexia), neurologic (cognitive defects, peripheral sensorimotor neuropathy, short term memory loss), hematologic (anemia), HTN and possible nephrotoxicity (elevated Cr)
Labs: anemia, elevated venous lead level, elevated serum zinc protoprophyrin level, hyperuricemia (due to impaired purine metabolism)
Imaging: basophilic stippling on peripheral smear
Tx: chelation therapy with calcium disodium EDTA
What is the ddx for upper motor neuron disease?
Leukodystrophies, vasculitis, brain mass, B12 deficiency
What is the ddx for anterior horn cell disease?
Spinal muscular atrophy (flaccid paralysis in infancy), ALS, paraneoplastic syndromes, poliomyelitis
What is the ddx for peripheral nerve disease?
Hereditary primary motor sensory neuropathy, GBS, diabetic neuropathy, amyloid neuropathy (myeloma), lead poisoning
What is the ddx for NMJ disease?
Myasthenia gravis, Lambert Eaton syndrome, organophosphate poisoning, botulism
What is the ddx for muscle fiber disease?
Muscular dystrophies, polymositis/dermatomyostitis, hypothyroidism, corticosteroids, HIV myopathy
What is RA cervical myelopathy?
Spinal cord compression due to atlantoaxial joint instability
Sxs: neck pain radiating to occipital region, slowly progressive spastic quadriparesis (numbness and tingling), painless sensory deficits in hands or feet, respiratory dysfunction (eg from vertebral artery compression)
Signs: protruding anterior arch of atlas, scoliosis w/ loss of cervical lordosis, UMN signs (eg spastic paresis, hyperreflexia, Babinski sign), Hoffman sign
What is a brain abscess?
Micro: s. aureus, v. streptococci, anaerobes
Pathogenesis: direct spread (eg sinusitis, otitis media), hematogenous spread (eg endocarditis)
Findings: headache, vomiting, fever, focal neurological deficits, seizure, ring-enhancing lesion w/ central necrosis on neuroimaging (CT, MRI)
Tx: CT-guided aspiration/surgical drainage, surgical biopsy, prolonged antibiotic therapy (eg metronidazole, ceftriaxone, vancomycin)
What is multiple system atrophy (Shy-Drager syndrome)?
Degenerative disease characterized by Parkinsonism, autonomic dysfunction (postural hypotension, abnormal sweating, disturbance of bowel or bladder control, abnormal salivation or lacrimation, impotence, gastroparesis), widespread neurological signs (cerebellar, pyramidal, or LMN)
Accompanying bulbar dysfunction and laryngeal stridor may be fatal
Tx: anti-Parkinsonism drugs are generally ineffective, treatment aimed at intravascular volume expansion w/ fludrocortisone, salt supplementation, alpha-adrenergic agonists, and application of constrictive garment to the lower body
How does a lesion in the posterior limb of the internal capsule (lacunar infarct) present?
Unilateral motor impairment, no sensory or cortical defects, no visual field abnormalities
