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Path 09 test 4
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78
Medical
Graduate
10/15/2009
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Term
Inclusions
 Definition
are abnormal nuclear or cytoplasmic structures. They are either the focal storage of metabolites, viral proteins or nucleoproteins, or the abnormal accumulation of structural proteins (e.g., neurofibrillary tangles, Lewy bodies).
Term
Lipofuscin
 Definition
An insoluble mix of proteins, lipids, and minerals that accumulates in neurons and astrocytes during the normal aging process.
Term
Neuronophagia
 Definition
phagocytosis of degenerating neurons, usually by macrophages. This is commonly seen after hypoxia/ischemic insults or in viral infections.
Term
Dying back degeneration
 Definition
a degeneration of the most distal portion of the axon followed by the progressive loss of more and more proximal regions. This is seen in toxic peripheral neuropathies.
Term
What are spheroids and what causes them?
 Definition
focal enlargement of an axon due to damage, regardless of cause: trauma, local areas of necrosis, or toxic-metabolic insults. Spheroids are a mixture of lysosomes, mitochondria, neurofilaments, and other cytoplasmic constituents. Slowing or cessation of axoplasmic transport at sites of damage presumably cause spheroids
Term
What are the two common pathologies of dendrites?
 Definition
1. Hypoplasia refers to an inadequate development of dendritic branches. This is seen in many types of mental retardation, including congenital hypothyroidism (cretinism).
2. Atrophy is a reduced volume and surface area of dendritic branches, commonly seen in neurodegenerative diseases.
Term
Neuritic senile plaques
 Definition
areas of degenerating axons and dendrites, mixed with microglia and astrocytes and associated with the extracellular deposition of amyloid seen in Alzheimer’s disease.
Term
Status spongiosis
 Definition
refers to a spongy state of the neuropil, the formation of fine to medium sized vacuoles representing swollen neuronal and astrocytic processes. This change is typical of transmissible spongiform encephalopathies, such as Creutzfeldt-Jacob disease.
Term
What are the 4 types of inclusions that were talked about involving astrocytes. Give a brief description of each
 Definition
1. Rosenthal fibers
2. Corpora Amylacea
3. Viral Inclusions
4. Tangle inclusions.
Rosenthal fibers are eosinophilic, refractile inclusions of intermediate filaments and small heat-shock proteins. They occur in low-grade, pilocytic astrocytomas, Alexander’s disease, and occasionally in old scars. Corpora amylacea are spherical accumulations of poly glucosan (branched-chain glucose polymers). They increase in number with age, particularly subpial and subventricular, and in glial scars. Viral inclusions occur in cytomegalovirus infections. Tangle inclusions similar to neurofibrillary tangles are also seen in astrocytes in some neurodegenerative disorders.
Term
1Congestive brain swelling
 Definition
- due to cerebral vasodilatation
- can be very rapid, especially in children
- trauma, hypoxia, hypercapnia
- when prolonged, vasogenic cerebral edema supervenes
Term
Brain edema
 Definition
- defined as an increase in volume and weight of the brain due to fluid
accumulation
- edema is a common complication of many kinds of intracranial lesions
- a serious complication because it produces an additional increase in volume
over and above that resulting from the lesion itself
- useful to divide cerebral edema into two categories – vasogenic and cytotoxic
Term
Cytotoxic edema
 Definition
refers to swelling of cellular elements in the presence of an intact BBB
- fluid is an ultrafiltrate and does not contain plasma proteins
Term
Vasogenic edema
 Definition
Most common form, results from increased vascular permeablity, incompetent BBB,
Term
The early edema after ischemic injury is ______, whereas the later edema has a _________ component
 Definition
Cytotoxic, Vasogenic.
a) early changes include an increase in water content, then swelling of astrocyte processes
b) after several hours, breakdown of the BBB occurs
Term
Duret hemorrhages
 Definition
appear in the lower midbrain and pons, and predominate in the midsagittal region. Duret hemorrhages are arterial, resulting from stretching of perforating vessels of the brainstem
Term
three examples of demyelinating disorders:
 Definition
1. MS
2. Acute disseminated encephalomyelitis
3. progressive multifocal leukoencephalopathy
Term
three examples of dysmyelinating disorders:
 Definition
1. metachromatic leukodystrophy
2. Krabbe’s leukodystrophy
3. adrenoleukodystrophy
Term
myelinolytic disorders
 Definition
1. central pontine myelinolysis
2. subacute combined degeneration
3. HIV vacuolar myelopathy
4. Toxic
Term
Demyelinating diseases in general
 Definition
- inflammatory, sporadic, and characterized by the immune-mediated destruction of biochemically normal myelin and its supporting cells
- axons are generally spared
- target is usually either central myelin (e.g. multiple sclerosis) or peripheral myelin (e.g. idiopathic polyneuritis)
Term
Dysmyelinating diseases(leukodystrophies) in general
 Definition
- non-inflammatory, familial, and characterized by the confluent destruction of chemically abnormal myelin and its supporting cells
- axonal loss is more prevalent than in demyelinating or myelinolytic diseases
- involvement of both central and peripheral myelin may occur, reflecting the biochemical similarities of these myelin.
Term
Hypomyelinating diseases in general
 Definition
- confluent abnormality in white matter with a general paucity of myelin deposition during development
- reduced quantity of myelin lipids and proteins rather than the chemically abnormal
- myelin is biochemically normal
Term
Myelinolytic diseases in general
 Definition
- non-inflammatory
- intramyelinic edema of chemically normal myelin with relative sparing of the supporting cells and axons, at least in the early stages of the disorder
- intramyelinic edema is recognized as splitting of the myelin sheath at the intraperiod line
Term
What histolological changes might you see in Acute MS
 Definition
- large hyper-reactive astrocytes (reactive astrocytosis)
- macrophages
- perivascular lymphocytes (helper and suppressor/cytotoxic T cells)
Term
Pathology of chronic multiple sclerosis
 Definition
- demyelination
- depressed greyish plaques
- small old reactive astrocytes
- few perivascular lymphocytes
- usually no macrophages
Term
ACUTE DISSEMINATED ENCEPHALOMYELITIS
 Definition
Demyelinating. Acute onset following viral infection or vaccination. Usually diffuse and monophasic.
Term
PROGRESSIVE MULTIFOCAL LEUKOENCEPHALOPATHY
 Definition
Demyelinating, infectious disease seen in immunocomprimised adults. progresses relentlessly until death, direct treatment towards underlying immunosuppression.
Term
METACHROMATIC LEUKODYSTROPHY (MLD)Biochemical defect
 Definition
Dysmyelinating. lysosomal enzyme, arylsulfatase A deficiency
- accumulation of sulfatide
Term
KRABBE’S DISEASE (GLOBOID CELL LEUKODYSTROPHY)
 Definition
Dysmyelinating. lysosomal enzyme, galactocerebroside-β-galactosidase
deficiency
- psychosine (a related galactocerebroside metabolite) toxicity
Term
ADRENOLEUKODYSTROPHY (ALD)
 Definition
Dysmyelinating. peroxisomal enzyme defect of an ATP-binding
cassette (ABC) transporter
- reduced capacity to form coenzyme A derivative of very long chain fatty acids
Term
CENTRAL PONTINE MYELINOLYSIS (CPM)
 Definition
Myelinolytic. - presentation with rapid onset of confusion, limb weakness (often progressing to
quadriparesis), conjugate gaze palsies, dysarthria, dysphagia, and hypotension
- associated with too rapid correction of hyponatremia (with extravascular
hypernatremia in affected areas and intramyelinic edema)
- outcome is usually fatal within a few weeks
Term
SUBACUTE COMBINED DEGENERATION
 Definition
Myelinolytic. - due to vitamin B12 (cobalamin) deficiency
- develops in ~40% of patients with untreated pernicious anemia
- early manifestations include paresthesias in the lower limbs, progressing to loss of
fine touch, vibration, and position sense
- further progression leads to spastic paraparesis, ataxia, and anesthesia of the lower
limbs and trunk
- etiology: defective methylation of myelin basic protein and other CNS proteins
(synthesis of methyl donor is dependent on methionine synthase, which is dependent
on vitamin B12)
- vacuolization of the posterior and lateral columns of the spinal cord is seen at the
light microscopic level
- by electron microscopy there is intramyelinic edema
Term
Which group of myelin disorders is characterized by intramyelinic edema
 Definition
Myelinolitic disorders
Term
HIV-ASSOCIATED VACUOLAR MYELOPATHY
 Definition
Myelinolytic. - AIDS patients with no detectable nutritional deficiency can show a progressive
myelopathy with pathological features identical to subacute combined degeneration
Term
TOXIC
 Definition
- various man-made compounds cause myelinolytic disorders
- two well known examples include triethyl tin and hexachlorophene, used in surface disinfectants
Term
Presentation of Metachromatic leukodystrophy
 Definition
in infancy – progressive motor disability
in childhood – behavioral and educational problems, gait disorder
in adults – psychosis, behavioral problems
Term
Krabbes Leukodystrophy presesntation
 Definition
in infancy – irritability, developmental failure, deteriorating motor function, tonic spasms, myoclonic jerks, hyperpyrexia, blindness, bulbar paralysis
in childhood – gait disorder, progressive spasticity, peripheral neuropathy, visual disturbance
Term
ADRENOLEUKODYSTROPHY Presentation –
 Definition
in infancy – hypertonia, seizures, failure to thrive, deafness,
retinal degeneration
in childhood – loss of skills, educational problems, dementia,
problems with hearing and vision, progressive
pyramidal, extrapyramidal, or cerebellar disorder
in adulthood – clumsiness and spasticity, schizophrenia-like
syndrome, dementia
Term
Arteriolar sclerosis
 Definition
Associated with hypertension and diabetes, vessels become hardened and lumen becomes narrow/obliterated and it leads to small infarcts that result in lacuni. Common in Basal Ganglia
Term
Most commonly encountered causative organisms according to patient age
 Definition
Neonates – Group B streptococci; E. coli
Infants and children – Haemophilus influenzae
(greatly reduced in USA but still prevalent in developing countries)
Adolescents and young adults – Neisseria meningitidis
Elderly – Streptococcus pneumoniae; Listeria monocytogenes
Term
Ring enhancing lesion in Immunocomprimised patient in thalamus or basal ganglia
 Definition
Toxoplasma until proven otherwise
Term
1
 Definition
Term
1
 Definition
Term
1
 Definition
Term
1
 Definition
Term
1
 Definition
Term
1
 Definition
Term
1
 Definition
Term
Chromatolysis
 Definition
results from axonal damage (including transection of the axon). The cell body becomes hypertrophic and loses its Nissl substance
Term
Kernig's signs
 Definition
triad of nuchal rigidity (neck stiffness), photophobia (intolerance of bright light) and headache
Term
Brudzinski's signs
 Definition
appearance of involuntary lifting of the legs in meningeal irritation when lifting a patient's head.
Term
Amaurosis fugax
 Definition
classically described as a transient monocular vision loss that appears as a "curtain coming down vertically into the field of vision in one eye;" Giant cell arteritis can result in granulomatous inflammation within the central rentinal artery and posterior ciliary arteries of eye, resulting in partial or complete occlusion, leading to decreased blood flow manifesting as amaurosis fugax
Term
Vascular Dementia
 Definition
 Sudden onset, stepwise course
 Focal motor, sensory, reflex findings
 Cognitive impairments predominantly in one
hemisphere
 Early seizures, gait impairment and
incontinence
 Stroke on CT and MRI
 Hachinski ischemia score, validated
Term
Meaning of Hachinski Score
 Definition
 0-2, Suggests Alzheimer’s disease
 2-4, Indeterminate
 >4, Suggests vascular dementia or
mixed vascular dementia and AD
Term
Creutzfeldt-Jakob Disease
 Definition
 Rapidly progressive (course usually <1 year)
 Onset often focal (ataxia, blindness)
 Startle myoclonus, rigidity
 Progressive, periodic discharges on EEG
 Transmissible by CNS tissue or blood
 Caused by a prion destroyed by chlorox and NaOH,
but not formaldehyde or alcohol
 Familial in about 10%, may be atypical
Term
Corticobasal Degeneration (CBD)
 Definition
 Sporadic, onset age >55
 Asymmetric rigidity
 Profound asymmetric apraxia
 Alien hand
 Dementia (mild)
 Neuronal loss in cortex and basal ganglia
 A tauopathy, achromatic 4R tau neuronal inclusions
Term
Progressive Supranuclear Palsy
 Definition
 Supranuclear gaze palsy
 Pseudobulbar palsy with dysarthria and
choking
 Ataxic gait and falling
 Limb and axial rigidity
 Frontotemporal dementia
 A Tauopathy, 4R primarily subcortical
neurofibrillary tangles
Term
Parkinson’s Disease
with Dementia
 Definition
Synucleinopathy
 Onset of motor symptoms first, especially tremor
 Motor symptoms precede dementia by a year or more
 Affects about 30% of patients with PD
 More common with increasing age of patient
 Treatment of motor symptoms can worsen or improve
dementia symptoms
 A synucleopathy
Term
Dementia with Lewy Bodies (DLB)
 Definition
Synucleinopathy
 Dementia with spontaneous parkinsonism
 Dementia precedes are begins at the same time as parkinsonism
 Visual hallucinations
 Unexplained fluctuations in attention and alertness
 Consensus clinical criteria - not yet validated
 Temporoparietal > frontal and occipital hypometabolism
Term
Frontotemporal Dementia (FTD)
 Definition
Tauopathy or other proeteins
 Insidious onset of progressive dementia
 Disturbing behavior and speech problems most
prominent, less evident memory loss
 Perseveration, decreased verbal fluency
 Typical behavioral changes including apathy, unrestrained and inappropriate social conduct
 Memory loss often not prominent; AD screening tests may be insensitive
 May be associated with motor neuron disease
 2nd most common dementing disease if age <65
Term
Symptomatic Treatment for Alzheimers
 Definition
 Cholinesterase inhibitors - offsets selective loss of
cholinergic neurons (n. basalis)
 Low affinity non-competitive NMDA antagonist
(offsets glutamate neurotoxicity)
Term
Drugs that Slow Progression of Alzheimers
 Definition
 Megadose vitamin E (offsets inflammatory response around neuritic plaques)
Term
Alzheimer’s Disease
 Definition
 Insidious onset of gradual, progressive dementia
 Memory loss usually initial and most prominent
symptom
 No focal weakness or sensory loss
 Gait normal and continent until late in the illness
 Familial in about 10%, several genetic defects
 NINCDS-ADRDA criteria, validated
Term
Definition of Dementia
 Definition
 A decline in intellectual function from a previous level of performance sufficient to impair daily activities in someone who is alert and cooperative
Term
What tests should be run to rule out treatable causes of dimentia?
 Definition
Thyroid function tests, vitamin B12 level, and serologic test for syphilis (e.g. VDRL). A tox screen could also be used to rule out medication induced dimentia.
Term
Treatment of Trigeminal neuralgia
 Definition
Carbemazepine
Term
fever + leukocytosis + stroke =
 Definition
Endocarditis until proven otherwise
Term
What do you get splinter hemorrhages from
 Definition
infective endocarditis
Term
thrombolysis for stroke: *tissue plasminogen activator (t-PA) contraindicated under what conditions
 Definition
– anticoagulation
– head trauma
– unclear onset of symptoms
- if there is a possible hemorrhage
Term
What is a med you can give someone with stroke
 Definition
Dyslipiddemic agents, get cholesterol down, lowers inflammation
Term
Carotid endarterectomy, when should it be done on someone with stroke
 Definition
Stenosis greater than 70%, below 50% not recommended.
Term
Main difference in how meningitis and encephalitis present
 Definition
Normal mental status w meningitis and altered with encephalitis
Term
Brudzinski’s Sign
 Definition
�� Examiner flexes patient’s neck and patient flexes hips and knees
Term
Kernig’s Sign
 Definition
�� Patient’s legs curled up, extending the knee causes pain
Term
Exposures and Bacterial Encephalitis, Raw meat, milk, cheese =
 Definition
Listeria monocytogenes
Term
Exposures and Bacterial Encephalitis barracks or dorms w rash
 Definition
N. Meningitidis
Term
Exposures and Bacterial Encephalitis, endemic country
 Definition
TB
Term
Exposures and Bacterial Encephalitis cats, usually kittens
 Definition
Bartonella henselae/Cat Scratch Disease
Term
Exposures and Bacterial Encephalitis ticks
 Definition
�� Borrelia burgdorferi/Lyme Disease
�� Rickettsia rickettsii/Rocky Mountain Spotted Fever
�� Francisella tularensis/Tualeremia (CNS complications rare)
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