Unit 3 - Neurology, Ophthalmology, Otolaryngology Flashcards
Most common cause of Rhinitis
Rhinovirus or adenovirus (he said adeno in video, rhino is written in book)
Allergic Rhinitis is what type of hypersensitivity reaction?
Type I
Protrusion of edematous, inflamed nasal mucosa
Nasal Polyp
3 diseases associated with Nasal Polyps
Repeated bouts of Rhinitis (most common)
Cystic Fibrosis
Aspirin-intolerant asthma
What is an angiofibroma and which age group is it most common in?
Benign tumor of nasal mucosa composed of large blood vessels and fibrous tissue
Adolescent males
How does an angiofibroma present?
Profuse epistaxis
What virus is Nasopharyngeal Carcinoma associated with and which populations is it seen in?
EBV
African children, Chinese adults
Most common cause of acute epiglottitis
H. influenzae type b
What is Laryngotracheobronchitis and what is the most common cause?
AKA Croup
Inflammation of upper airway
Parainfluenza virus
How does croup present?
Hoarse “barking” cough
Inspiratory stridor
What is tissue is a vocal cord nodule composed of?
Degenerative (myxoid) connective tissue
How do you treat a vocal cord nodule?
Rest - due to excessive use
What is a laryngeal papilloma?
Benign papillary tumor of the vocal cord
What causes a laryngeal papilloma and how does presentation differ in adults vs. kids?
Due to HPV 6 & 11
Adults - single papilloma
Children - multiple papillomas
Risk factors for laryngeal carcinoma
Alcohol, tobacco
Rarely comes from laryngeal papilloma
Why does a cleft lip or palate form?
Because the 5 facial prominences fail to fuse during development
Painful, superficial ulceration of oral mucosa characterized by grayish base surrounded by erythema
Aphthous Ulcer
What is Behcet Syndrome?
Recurrent aphthous ulcers, genital ulcers, and uveitis
What causes Behcet Syndrome and what usually predisposes one to it?
Caused by immune complex vasculitis involving small vessels
Comes after viral infection
Where does HSV-1 remain dormant and what causes reactivation?
Dormant in ganglia of trigeminal nerve
Stress and sunlight cause reactivation
2 precursor lesions of oral squamous cell carcinoma
Oral Leukoplakia - white plaque that cannot be scraped away
Erythroplakia - red plaque, vascularized leukoplakia
Which is more indicative of squamous cell dysplasia, oral leukoplakia or erythroplakia?
Erythroplakia
How does Mumps present?
Bilateral inflamed parotid glands
What enzyme is characteristically increased in Mumps?
Serum amylase
3 complications of Mumps
Orchitis
Pancreatitis
Aseptic Meningitis
What is Sialadenitis?
Inflammation of the salivary gland
What is the most common cause of Sialadenitis?
Obstructing stone leading to Staph Aureus infection - unilateral
Most common tumor of the salivary gland
Pleomorphic adenoma (benign)
Where does a pleomorphic adenoma usually arise and how does it present?
Arises in parotid gland
Painless**, circumscribed mass at angle of jaw
Benign cystic tumor of salivary gland that has abundant lymphocytes and germinal centers (lymph-like stroma)
Warthin Tumor
Where does a Warthin Tumor usually arise?
Parotid gland
Most common malignant tumor of salivary gland
Mucoepidermoid Carcinoma
Where does a Mucoepidermoid Carcinoma usually arise?
Parotid gland - involves facial nerve
Pathology of Myasthenia Gravis
Autoantibodies are produced against ACh receptor at neuromuscular junction
Which muscles do Myasthenia Gravis classically affect and what worsens and improves the weakness?
Eye muscles
Improves with rest
Worsens with use
Which 2 things can improve the symptoms of Myasthenia Gravis?
Anticholinesterase agents
Thymectomy if associated with thymic hyperplasia or thymoma
Pathology of Lambert-Eaton Syndrome
Antibodies produced against presynaptic Ca+ channel of neuromuscular junction leading to impaired ACh release
How does Lambert-Eaton Syndrome arise?
As a paraneoplastic syndrome most commonly due to small cell carcinoma of lung
What are the clinical features of Lambert Eaton Syndrome?
Proximal muscle weakness that improves with use
Eyes are usually spared
Anticholinesterase agents do not improve symptoms
The wall of the neural tube forms _____ tissue, the hollow lumen forms _____ and ______, and the neural crest forms the ______.
Wall - central nervous system tissue
Lumen - ventricles, spinal cord canal
Crest - peripheral nervous system
Absence of fetal skill and brain leading to maternal polyhydramnios
Anencephaly
How can you detect neural tube defects during prenatal care?
Levels of alpha-fetoprotein (AFP) are elevated in amniotic fluid and maternal blood
What is Spina Bifida?
Failure of posterior vertebral arch to close - results in vertebral defect
Congenital stenosis of channel that drains CSF from 3rd ventricle into 4th ventricle
Cerebral Aqueduct Stenosis
Most common cause of hydrocephalus in newborns
Cerebral Aqueduct Stenosis
What is the Dandy-Walker malformation?
Congenital failure of the cerebellar vermis to develop
How does Dandy-Walker malformation present?
Massively dilated 4th ventricle with absent cerebellum
Congenital downward displacement of cerebellar vermis and tonsils through the foramen magnum
Arnold-Chiari Malformation Type II
What are 2 common associations with Arnold-Chiari malformation?
Meningomyelocele and syringomyelia
What is Syringomyelia?
Cystic degeneration of spinal cord
What spinal levels does Syringomyelia usually occur at?
C8 - T1
How does Syringomyelia present?
Loss of pain and temperature in “cape like” distribution
Spares fine touch and position sense
If syrinx expands in syringomyelia, which other spinal tracts can it affect and what are the associated symptoms?
Anterior horn - damages LMN, leading to muscle atrophy, weakness, decreased muscle tone, impaired reflexes
Lateral horn of hypothalamospinal tract - horner syndrome with ptosis, miosis, and anhidrosis
What is Poliomyelitis?
Damage to anterior motor horn due to poliovirus infection
How does Poliomyelitis present?
LMN signs - flaccid paralysis with muscle atrophy, fasciculations, weakness with decreased muscle tone, impaired reflexes, negative Babinski sign
Inherited (autosomal recessive) degeneration of anterior motor horn
Werdnig-Hoffman Disease
How does Werdnig-Hoffman Disease present?
Floppy baby - death within few years after birth
Degenerative disorder of upper and lower motor neurons of corticospinal tract
Amyotrophic Lateral Sclerosis (ALS)
What is an early sign of ALS and how is it differentiated from Syringomyelia?
Early sign is atrophy and weakness of hands
No sensory impairment in ALS - different from Syringomyelia
What is Friedreich Ataxia?
Degenerative disorder of cerebellum and spinal cord
What are the symptoms associated with Friedreich Ataxia?
Ataxia, loss of vibratory sense and proprioception, muscle weakness in lower extremities, loss of deep tendon reflexes
What causes Freidreich Ataxia?
Genetic - AR, GAA repeat in frataxin gene
Results in iron buildup and free radical damage
At what ages does Freidreich Ataxia present and what is it associated with?
Early childhood
Hypertrophic cardiomyopathy
What is Meningitis?
Inflammation of leptomeningees (pia + arachnoid)
Classic triad of Meningitis
Headache, nuchal rigidity, fever
Photophobia, vomiting, and mental status may also be present
How do you diagnose Meningitis?
Lumbar puncture (between L4 and L5)
What are the CSF findings in bacterial meningitis, viral meningitis, and fungal meningitis?
Bacterial - neutrophils with decreased CSF glucose
Viral - lymphocytes with normal CSF glucose
Fungal - lymphocytes with decreased CSF glucose
Complications of bacterial meningitis
Death (herniation), hydrocephalus, hearing loss, seizures
4 major etiologies causing global cerebral ischemia
- ) Low perfusion (atherosclerosis)
- ) Acute decrease in blood flow (cardiogenic shock)
- ) Chronic hypoxia (anemia)
- ) Repeated episodes of hypoglycemia (insulinoma)
Clinical differences between mild, moderate, and severe global cerebral ischemia
Mild - transient confusion with prompt recovery
Moderate - infarcts in watershed areas and vulnerable areas (cerebellar signs, long term memory damage)
Severe - diffuse necrosis, survival leads to vegetative state
What is the definition of an Ischemic Stroke?
Regional ischemia to the brain resulting in focal neurologic deficits lasting > 24 hours
How does an ischemic stroke differ from a TIA?
TIA 24 hours
Subtypes of ischemic strokes and what are they caused by?
Thrombotic Stroke - due to rupture of atherosclerotic plaque
Embolic Stroke - due to thromboemboli
Lacunar Stroke - occurs secondary to hyaline arteriolosclerosis, complication of hypertension
Where in blood vessels does atherosclerosis usually develop and what type of infarct does a thrombotic stroke result in?
Develops at branch points of arteries
Pale infarct in periphery of cortex
What is the most common source of emboli in an embolic stroke?
Left side of heart (a fib)
Which artery does an embolic stroke usually involve and what type of infarct does it result in?
Middle Cerebral Artery
Hemorrhagic infarct at periphery of cortex
Which vessels does a lacunar stroke most commonly involve and what type of infarct does it result in?
Lenticulostriate vessels
Small cystic areas of infarction
Ischemic stroke results in _______ _______
Liquefactive necrosis
What is an Intracerebral Hemorrhage and what is it classically caused by?
Bleeding into brain parenchyma
Due to rupture of Charcot-Bouchard microaneurysms of the lenticulostriate vessels
How does Intracerebral Hemorrhage clinically present?
Severe headache, nausea, vomiting, eventual coma
What is a Subarachnoid Hemorrhage and what is it most commonly caused by?
Bleeding into subarachnoid space
Most commonly due to rupture of berry aneurysm
How does a Subarachnoid Hemorrhage present clinically?
Sudden headache (worst headache of my life) Nuchal rigidity
What is an Epidural Hematoma and what is it classically caused by?
Collection of blood between dura and skull
Due to fracture of temporal bone with rupture of middle meningeal artery
What is a Subdural Hematoma and what is it classically caused by?
Collection of blood underneath dura (covers brain)
Due to tearing of bridging veins that lie between dura and arachnoid - seen with trauma
How would a subdural vs. epidural hematoma present on CT and in terms of neurological signs?
Subdural - crescent shaped lesion on CT, progressive neurological signs
Epidural - lens shaped lesion on CT, lucid interval may precede neurological signs
What is a complication of both epidural and subdural hematomas?
Herniation (lethal)
Displacement of brain tissue due to mass effect or increased intracranial pressure
Herniation
What is a Tonsillar Herniation and what does it lead to?
Displacement of cerebellar tonsils into foramen magnum
Compression of brainstem leads to cardiopulmonary arrest
What is a Subfalcine Herniation and what does it lead to?
Displacement of cingulate gyrus under the falx cerebri
Compression of anterior cerebral artery leads to infarction
What is a Uncal Herniation and what does it lead to?
Displacement of temporal lobe uncus under the tentorium cerebelli
Compression of CN III - down and out eye, dilated pupil
Compression of posterior cerebral artery - infarction of occipital lobe
Rupture of paramedian artery - Duret (brainstem) hemorrhage
____ myelinate CNS, _____ myelinate PNS
Oligodendrocytes; Schwann cells
Inherited mutations in enzymes necessary for the production or maintenance of myelin
Leukodystrophies
What is the most common Leukodystrophy?
Metachromatic Leukodystrophy (deficiency of arylsulfatase)
_______ (leukodystrophy) is due to deficiency of galactocerebrosidase
Krabbe Disease
_____ (leukodystrophy) is due to impaired addition of CoA to long chain fatty acids
Adrenoleukodystrophy
Autoimmune destruction of CNS myelin and oligodendrocytes
Multiple Sclerosis
Most common chronic CNS disease of young adults
Multiple Sclerosis
How does Multiple Sclerosis present and what are some clinical features?
Presents as relapsing neurological deficits with periods of remission
Features - blurred vision in one eye, vertigo, scanning speech, internuclear ophthalmoplegia, hemiparesis or unilateral loss of sensation, blower extremity loss of sensation or weakness, bowel/bladder/sexual dysfunction
How do you make a diagnosis of Multiple Sclerosis?
MRI & Lumbar Puncture
MRI - plaques
LP - increased lymphocytes, increased Ig with oligoclonal IgG bands on electrophoresis, myelin basic protein
How do you acutely and chronically treat Multiple Sclerosis?
Acute attacks - high dose steroids
Chronic - interferon beta
What is Subacute Sclerosing Panencephalitis and what is it due to?
Progressive, debilitating encephalitis leading to death
Due to slowly progressing, persistent infection of brain by measles virus
JC virus infection of oligodendrocytes leading to death
Progressive Multifocal Leukoencephalopathy
What is Central Pontine Myelinolysis and what is it due to?
Focal demyelination of the pons (anterior brainstem)
Due to rapid IV correction of hyponatremia
How does Central Pontine Myelinolysis present clinically?
“Locked in” syndrome - acute bilateral paralysis
Group of disorders characterized by loss of neurons within the gray matter
Degenerative Disorders/Dementias
Degenerative disease of cortex
Alzheimers Disease
Most common cause of dementia
Alzheimers Disease
Clinical features of Alzheimers Disease
Slow onset memory loss and progressive disorientation
Loss of learned motor skills and language
Changes in behavior and personality
Patients become mute and bedridden
Focal neurological deficits in later disease
Common cause of death in Alzheimers Disease
Infection
____ allele increases risk of Alzheimers, _____ allele decreases risk
e4; e2
Both part of apolipoprotein E
What mutations are familial cases of Alzheimers associated with?
Presenilin 1 and Presenilin 2
What are the neuritic plaques in Alzheimers composed of?
A(Beta) amyloid with entangled neuritic processes
Morphological features of Alzheimers
Cerebral atrophy with narrowing of gyri, widening of sulci, dilation of ventricles
Neuritic plaques
Neurofibrillary tangles (tau protein)
Loss of cholinergic neurons in nucleus basalis of Meynert
What is Vascular Dementia?
Multifocal infarction and injury due to hypertension, atherosclerosis, or vasculitis
Degenerative disease of frontal and temporal cortex that spares the parietal and occipital lobes
Pick Disease
What is Pick Disease characterized by?
Round aggregates of tau protein in neurons of cortex
Degenerative loss of dopaminergic neurons in substantia nigra of basal ganglia
Parkinsons Disease
Clinical features of Parkinson’s Disease
T - tremor at rest, disappears with movement
R - rigidity (cogwheel rigidity)
A - akinesia/bradykinesia (slowing of voluntary movement, expressionless face)
P - postural instability and shuffling gait
What type of inclusions are found in the neurons in substantia nigra in Parkinsons Disease?
alpha-synuclein inclusions (Lewy Bodies)
What is Huntingtons Disease?
Degeneration of GABAergic neurons in the caudate nucleus of the basal ganglia
What causes Huntington Disease?
AD disorder characterized by CAG repeats in huntingtin gene
How does Huntington Disease present?
Chorea that can progress to dementia and depression
What is normal pressure hydrocephalus?
Increased CSF resulting in dilated ventricles
How does normal pressure hydrocephalus present?
Wet, Wobbly, Wacky
Urinary incontinence, gait instability, dementia
How do you treat normal pressure hydrocephalus?
Ventriculoperitoneal shunting
What are the Spongiform Encephalopathies caused by?
Beta-pleated conformation of the prion protein, degenerative disease
3 types of Spongiform Encephalopathies
Creutzfeldt-Jakob Disease - most common, usually sporadic, presents with rapidly progressive dementia with ataxia and startle myoclonus
Variant CJD - related to exposure to bovine spongiform encephalopathy
Familial Fatal Insomnia - inherited form, severe insomnia and exaggerated startle response
Common sources of metastatic CNS tumors
Lungs, breast, kidneys
In adults, primary tumors are usually ______ whereas in children, primary tumors are usually _____ [locations]
Supretentorial; infratentorial
Most common primary malignant CNS tumor in adults
Glioblastoma Multiforme
Malignant, high grade tumor of astrocytes
Glioblastoma Multiforme
Histological characterization of Glioblastoma Multiforme
Center of necrosis surrounded by pseudopalisading tumor cells which are GFAP positive
Benign tumor of arachnoid cells
Meningioma
Most common benign CNS tumor in adults
Meningioma
Histology of Meningioma
Whorled pattern sometimes with psammoma bodies
Benign tumor of schwann cells
Schwannoma
Tumor cells in Schwannoma are ____ positive
S-100
Malignant tumor of oligodendrocytes
Oligodendroglioma
What does imaging reveal on an Oligodendroglioma?
Calcified tumor in the white matter
Benign tumor of astrocytes
Pilocytic Astrocytoma
Most common CNS tumor in children
Pilocytic Astrocytoma
Biopsy of Pilocytic Astrocytoma shows ____ fibers, ____ bodies, and tumor cells that are ___ positive
Rosenthal Fibers, eosinophilic granular bodies, GFAP positive
Malignant tumor derived from granular cells of the cerebellum (neuroectoderm)
Medulloblastoma
In which population does a Medulloblastoma usually arise and what is the prognosis?
Children, poor prognosis - rapidly spreads via CSF
Malignant tumor of ependymal cells seen in children
Ependymoma
Where does an ependymoma most commonly arise?
4th ventricle
Benign tumor that arises from epithelial remnants of Rathke’s pouch
Craniopharyngoma
How does a craniopharyngoma present?
Supratentorial mass in children/young adults
May compress optic chiasm leading to bilateral hemianopsia
