Neurology Flashcards
Seen in acute hypoxia/ischemia
Evident by 12-24 hours
Shrinkage of cell body, pyknosis of nucleus, nucleolar disappearance, eosinophilia
Acute neuronal injury
Red neurons
Hallmark of acute neuronal injury
12-24 hours
Loss of Nissl substance
Seen in chronic and progressive neurodegenerative disease
Cell loss, reactive gliosis
Subacute and chronic neuronal injury
Degeneration
Seen during regeneration
Increased protein synthesis with axonal sprouting
Axonal reaction
Seen in aging, viral infections and degenerative diseases
Intracytoplasmic accumulation
Neuronal inclusions
Site of protein synthesis of neurons
Granular bodies of RER
Nissl susbtance
HSV body
Cowdry type A in temporal lobe
Rabies body
Negri body in pyramida cells of hippocampus and purkinje cells of cerebellum
Alzheimer’s body
Neurofibrillary tangles of hyperphosphorylated tau proteins
Parkinson’s disease body
Lewy Body of alpha synuclein protein
Hypertrophy and hyperplasia of astrocytes
Gliosis
Astrocyte functions
Metabolic buffers/detoxifiers
Control flow of substances between BBB and CSF
Recycle glutamate
Eosinophilic structures that occur within ASTROCYTIC processes that are found in regions of long-standing gliosis and pilocytic astrocytoma
Rosenthal fibers
Basophilic and lamellated structures found in advancing age, representing a degenerative change in astrocytes
Corpora amylacea
Sites where corpora amylacea are found
Brain
Lung
Prostate
Sum of the components of the intracranial cavity is constant
Brain, Blood, CSF
Monroe Kelly Doctrine
Sequence of compensation
CSF -> Venous blood -> Arterial blood (ischemia) -> Brain (herniation)
Due to BBB disruption and increased vascular permeability
Increased fluid leakage
Seen in inflammation or neoplasms
Vasogenic edema
Due to CNS injury that prevents maintenance of membrane ionic gradient
Increased CSF secretion
Seen in hypoxic/ischemic injury
Cytotoxic edema
Only type of cerebral edema responsive to steroids
Vasogenic edema
Increase in ventricular CSF volume due to loss of brain parenchyma
Hydrocephalus ex vacuo
Alzheimer’s
Dementia
Most common cause of congenital hydrocephalus
Congenital Aqueductal Stenosis
Cushing’s triad
Widened pulse pressure
Hypertension
Irregular breathing
Bradycardia
due to pressure on vagus nerve
Asymptomatic bony defect or a severe malformation with a flattened, disorganized segment of spinal cord
Spina bifida
Extension of CNS tissue through a defect in the vertebral column
Myelomeningocoele
Diverticulum and malformed brain tissue extending through a defect in cranium
Encephalocoele
Malformation of the anterior end of the neural tube
Anencephaly
Completely open brain and spinal cord
Craniorachischisis
Occipital skull and spine defect with extreme retroflexion of the head
Iniencephaly
Deficiency of at least two vertebral arches
Covered with lipoma
Closed spinal dysraphism
Prescribed period of intake of folic acid in women desirious of pregnancy
1 month before and first 3 months of pregnancy
400 mcg
0.4 mg
Reduced number of gyri
Lissencephaly
Small and irregular formed convolutions
Polymicrogyria
Incomplete separation of cerebral hemispheres across the midline
Holoprosencephaly
Associated with mental retardation
Agenesis of corpus callosum
Tonsillar extension into vertebral canal
Arnold Chiari Type I
Small posterior fossa
Vermis extension into foramen magnum
Hydrocephalus
Myelomeningocoele
Arnold Chiari Type II
Enlarged posterior fossa
+/- vermis
Large midline cyst
Dandy Walker
Fluid filled cavity in central canal from tumors or trauma
Pain centers of ventral white commisure damaged loss of pain and temp sensation in UE
Syringomyelia
Placque jaune are most commonly found at sites of
Can cause epileptic foci
contrecoup injury
Occurs in deep white matter region, cerebral peduncles, superior colliculi, deep reticular formation and brachium conjunctivum
Characterized by widespread and asymmetric axonal swellings
Coma shortly after trauma
Diffuse Axonal Injury
Pterion is the union of the
Frontal
Parietal
Sphenoid
Temporal
Chronic traumatic encephalopathy due to repeated head trauma causing accumulation of tangles in frontal and temporal lobes
Dementia pugilistica
Single most common cause of CVD
Cardioembolic stroke
Most sensitive neurons to hypoxia
Pyramidal cell layer of hippocampus (area CA1)
Cerebellar purkinje cells
Pyramidal neurons in cerebral cortex
Areas of the brain with little collateral flow
Thalamus
Basal ganglia
Deep white matter
Most common site of cardiam thromboemboli lodging
MCA
Most commonly associated with atherosclerosis and plaque rupture
Especially at Carotid bifurcation, MCA, Basilar artery
Thrombotic
Cytotoxic and vasogenic edema
Loss of gray and white matter differentiation
First 12 hours CVD infarct
Neutrophils (weeks)
Macrophages (months to years)
12-48 h CVD infarct
Reactive astrocytes
May be cause of seizure
48h-1 week CVD infarct
Angiogenesis and gliosis
1 month onwards CVD infarct
Golden hour for rTPA therapy in CVD
3-4.5 hours
Infarcts <15 mm Most common in lenticular nucleus Putamen Thalamus Internal capsule Deep white matter Caudate Pons
Lacunar infarct
Slit-like cavities secondary to resporption of hemorrhage
Slit hemorrhage
Cortical > subcortical
Dementia
Gait
Pseudobulbar signs +/- focal neurologic deficits
Vascular dementia
Affects Subcortical > cortical
Dementia (parasagittal)
Gait
Incontinence
Binswanger disease
Most common cause of intraparenchymal hemorrhage
Ganglionic (basal ganglia and thalamus) - HTN Putamen
Lobar - cerebral amyloid angiopathy
CHTN is associated with development of these microaneurysms in the basal ganglia (putamen)
Charcot bouchard
Cerebral amyloid angiopathy most commonly in lobar hemorrhages are located in
Leptomeningeal (arachnoid and pia)
Cerebral cortical arterioles
SAH is increased in
Autosomal dominant polycystic kidney disease
Ehlera Danlos
Marfan
NF Type I
Pathognomonic finding of Waterhouse Friedrichsen Syndrome
Purpura fulminans
Most common cause of aseptic or acute viral meningitis
Enterovirus
Antibiotic approved for prevention of MAC
Azithromycin
Neurosyphilis patterns of involvement
Meningovascular
Paretic
Tabes dorsalis
Impaired joint position sense
Loss of pain sensation
Areflexia
Charcot joints (skin and joint)
Tabes Dorsalis
HSV meningitis affected site
Inclusion body
Inferior and medial regions of temporal lobes
Orbitofrontal gyri
Cowdry Type A
CMV Meningitis causes
Periventricular necrosis
Microcephaly and periventricular calcifications
Most common source of congenital infections
Polio virus affects
Anterior horn motor neurons of spinal cord
First symptom of rabies virus
Local paresthesia at site of bite
Rabies virus binds using
And inhibits
Glycoproteins
Nicotinic receptor in brain
Rabies body
Negri bodies
Pyramidal neurons of hippocampus and purkinje cells of cerebellum
HIV infects the cell
Macroglia
Because it contains CD4 receptors
HIV causes
IRIS (immune reconstitution inflammatory syndrome; paradoxical deterioration starting therapy)
Dementia due to inflammatory reactivation of microglia
JC Polyoma virus infects the cell
Oligodendrocyte causing demyelination
Immunosuppresed
JC Polyomavirus causes
Progressive multifocal leukoencephalopathy
C neoformans preferentially affects
Basal meninges hydrocephalus
Soap bubble lesions
Most common cause of brain abscess in HIV individuals
Cerebral toxoplasmosis
Cerebral toxoplasmosis on MRI
Multiple ring-enhancing lesions
Central necrosis, organisms in the intermediate zone, tachyzoites and bradyzoites in periphery
Triad of congenital toxoplasmosis
Hydrocephalus
Chorioretinitis
Calcification
Naegleria from swimming in warm and still waters causes
Primary amebic encephalitis
Acanthamoeba resulting in coma and death in weeks to months is usually associated with immunosupression causes
Granulomatous amebic meningoencephalitis
Cerebral malaria is caused by
Plasmodium falciparum
vascular dysfunction and reduced blood flow
Prion
CJD
Gerstmann-Straussler-Scheinker
Fatal familial insomnia
Kuru
Spongiform change and rapid dementia
Prions
Most common prion disease
characteristic of
Creutzfeld Jacob Disease
Startle myoclonus
Autoimmune demyelinating disorder
Distinct episodes of neurologic deficits separated in tine, attributable to white matter lesions that are separated in space
Most common demyelinating disorder
Relapsing remitting
Multiple sclerosis
Multiple sclerosis radiographic feature
Dawson’s fingers
Mutliple sclerosis CSF analysis
+ oligoclonal IgG bands
Multiple sclerosis frequent initial manifestation
Visual impairment
Internuclear opthalmoplegia
Criteria for diagnosis of Multiple Sclerosis
McDonald’s Criteria
2 or more clinical attacks
2 or more lesions
Syndrome with synchronous bilateral optic neuritis and spinal cord demyelination
“Asian MS”
Neuromyelitis optica
Devic’s disease
Neuromyelitis optica antibody analysis
+ aquaporin 4
Tx plasmapharesis, anti-CD20
2-6 days after rapid correction of hyponatremia
acute disorder characterized by loss of myelin in the BASIS PONTIS and portions of PONTINE TEGMENTUM
Rapidly evolving quadriplegia
Central Pontine Myelinosis
Locked-in
Limit of correction for sodium
8-10 meqs/day
Most common cause of dementia in older adults
Agnosia Aphasia Apraxia Visuospatial disorientatiob Executive dysfunction
Alzheimer’s disease
Alzheimer’s treatment
Donepezil + Memantine
Cholinesterase inhibitor that improves memory and attention
Donepezil
NMDA antagonist acetylcholinesterase inhibitor for moderate to severe dementia
Memantine
Alzheimer Disease accumulation
Plaque (beta amyloid) Neurofibrillary tangle (hyperphosphorylated tau) correlates better with degree of dementia
Most common terminal event in Alzheimer’s
Pneumonia
Prominent behavioral and personality changes
Language defixit
Memory loss
Frontotemporal dementia
Frontotemporal dementia hallmark
Pick bodies - aggregates of tau
Atrophy of the frontal and temporal lobes
Parkinson’s disease accumulation
Lewy body (alpha-synuclein)
Parkinson’s anatomic changes
Pallor of substantia nigra
Basal nucleus of Meynert (cholinergic)
Dorsal motor nucleus of X
Multiple System Atrophy neuroanatomical circuits affected
Striatonigral (leading to Parkinsonism)
Olivopontocerebellar (leading to ataxia)
Autonomic nervous system (autonomic dysfunction with OH)
Parkinsonism
Ataxia
Autonomic dysfunction; OH
Multiple System Atrophy
Multiple System Atrophy radiographic feature
Hot cross bun sign
Atrophy of pontocerebellar tract
Autosomal dominant
Progressive movement disorders
Dementia
Degeneration of striatal neurons
Generalized jerky and hyperkinetic movements (choreoathetosis)
Huntington disease
Huntington disease is characterized by
CAG repeat expansion
Huntingin gene
Box car ventricle from atrophy of caudate nucleus
Huntington disease
Fragile X Syndrome trinucleotide repeat expansion
CGG
Myotonic dystrophy trinucleotide repeat
CTG
ALS mutation
SOD gene
ALS hallmark
Bunina bodies (remnants of autophagic vacuoles)
ALS anatomical changes
thin anterior roots of spinal cord
atrophy of precentral gyrus
ALS tx
Riluzole
Progressive muscular atrophy
LMN>UMN
Primary lateral sclerosis
UMN>LMN
Progressive bulbar palsy
Cranial motor nuclei
Marked loss of lower motor neurons resulting in progressive weakness
Spinal Muscular Atrophy
Most severe form of SMA
Type I Werdnig Hoffman disease
Acute onset of psychotic symptoms
Opthalmoplegia
Reversible
Hemorrhage and necrosis in the mamillary bodies and walls of 3rd and 4th ventricle
Wernicke’s encephalopathy
Short term memory loss and confabulation
Irreversible
Lesions in the dorsomedial nucleus of the thalamus
Korsakoff syndrome
Alcohol causes impaired absorption of
Vit B1
Causes degeneration of ascending and descending tracts due to defect of myelin formation
B12 deficiency
Hypoglycemia Type II DM
<70 mg/dl
Hypoglycemia w/o T2DM
<50 mg/dl
Confusion Deliriun Headache Dizziness Mood and personality changes Paresthesia Seizures Blurred vision
Neuroglycopenic
Most common manifesfation of hepatic encephalopathy
Inverted sleep wake pattern
Asterixis
Seizure
Carbob monoxide causes selective injury of
Bilateral globus pallidus
Cerebral cortex
Hippocampus
Cerebellum
Ethanol causes atrophy of
anterior vermis
Drunk level
0.08 % blood alcohol
Radiation causes
Marked tissue edema
Most common CNS tumor
Glioma
Astrocytoma
Fever, rash, sore throat, cervical and axillary LN
Hepatosplenomegaly
Young adult
Infectious Mononucleosis
Psammoma bodies
Papillary Thyroid carcinoma
Meningioma
Ovarian cystoadenocarcinoma
Most common primary site of originating metastases
Lung
Paraneoplastic syndrome
Antibodies against voltage-gated calcium channels in the presynaptic terminal of NMJ
Lambert-Eaton Myasthenic Syndrome
Small cell lung cancer
Paraneoplastic Syndromes
ACTH
SIADH
LEMS