Exam 3 powerpoints Flashcards
What is GFAP
a glial stain, used to find glial cell tumors, turns glial cells brown
What are the charactersitics of neoplastic cells
They grow autonomously, are insensitive to inhibitory signals, dont die off, are malignant, limitless replication
What are the tumor classifications
- primary (originate inside brain) or secondary (outside brain)
- Intra-axial (inside brain) or extra axial (in nerves, skull, meninges, or pituitary gland)
- Benign or malignant
What are the three neuroglial cell tumors
Glial cell tumor, neuronal tumor, embryonal tumors
What are two types of Glial cell tumors
Astrocytic tumors, and glioblastoma
What is an example of a Neuronal tumor
ganglioglioma
what is a type of embyronal tumor
medulloblastoma
What is the most common type of tumor in adults
Glioblastoma (55%)
what is the most common type of tumor in infants
Medulloblastoma
What are the two grades for histology in tumors
High grade: malignant/fast growing
Low grade: benign/slow growing
What are the 4 classifications of tumors. Describe them
Grade 1: Pilocytic astrocytoma, circumscribed childhood
Grade 2: Diffuse astrocytoma, diffusely infiltrating, nuclear atypia
Grade 3: Anaplastic astrocytoma, mitotic figures
Grade 4: glioblastoma, endothelial proliferation/ necrosis
What do both grade 3 and 4 tumors show
mitosis Angiogenesis
Necrosis
How do you determine whether a tumor is malignant in a histology slide
There are more than three mitotic cells present
What are the 4 cell markers of malignancy
Nuclear pleomorphism (weird shaped) and atypia
Mitoses
Microvascular proliferation
Necrosis
Why are Low grade tumors hard to detect
They grow so slowly that they look like their cells of origin ( blend in with the cells)
What are the direct effects of a tumor
Space occupying effects with increased intracranial pressure (ICP)
What are the causes of ICP
Direct compression of brain, hemorrhage within tumor, Edema, Impaired CSF flow
What are symptoms of a brain tumor
Headaches that awaken you, increased ICP, seizures (most common in adults), focal neurological deficits, hormonal changes
What does a pilocytic astrocytoma present as
Tumor of cerebellum, often with cyst, rosenthal fibers, and piloid cells, no mitosis
What is the most common tumor in children
Pilocytic astrocytoma
Describe a meningioma
Extra-axial, attatched to dura, meningothelial whorls, psammoma bodies, affect women twice as much as men
Describe Neuronal and axonal injury
Injury of the white matter that causes impaired axoplasmic transport
What is Azarcon
Remedy for diarrhea that contains 85-96% lead
What is the primary neurological effect of neurotoxicity of lead in childhood
Cerebral edema
What are some adverse outcomes of Neurotoxicity of lead in childhood
Aggression
Hyperactivity
Antisocial behavior
Learning disability
What type of neurons do metals kill
Brain and peripheral neurons
What is a symptom of Arsenic poisoning
Severe abdominal pain
What are some symptoms of Mercury poisoning
numbness in fingers and toes, and a rash with no fever
What is a treatment for mercury poisoning
Chelation, EDTA
What does inhalation of Mercury cause
necrotizing bronchitis, pneumonitis, death
What are the early symptoms of mercury poisoning
insomnia, forgetfulness, anorexia, mild tremor
What are the late symptoms of mercury poisoning
progressive tremor and erethism
What are the most common symptoms of Wernicke-Korsakoff syndrome (WKS)
Eye abnormalities (nystagmus), Ataxia, and mental symptoms
What is the pathology of WKS
Lesions in the midline: mammillary bodies, hypothalamus, thalamus, periaqueductal gray, colliculi, and floor of the fourth ventricle
What is WKS caused by
Vitamin B1 (thiamine) deficiency
What is Midline alcoholic cerebellar degeneration
Ataxia of stance and gait more than arms. Insidious onset and chronic course
Pathologically, there is loss of Purkinje and granular neurons
What does Vitamin E deficiency cause
causes sensory peripheral neuropathy, ataxia, retinitis pigmentosa, and skeletal and cardiac myopathy
What is the pathology for Vitamin E deficiency
Dorsal root neurons: Early loss of distal region of central projection
Spinal cord: Loss of fibers in posterior & Clarke column
Axon swelling: in cuneate & gracile nuclei
What does Vitamin B12 deficiency cause
Subacute combined degeneration
How does Vitamin B12 deficiency affect the spinal cord and peripheral nerve
Spinal cord: multifocal axonal loss & demyelination
Cervical & thoracic cord
Posterior column
Peripheral nerve: Axonal loss ± demyelination
The most common cause of vitamin B12 deficiency is
pernicious anemia, an autoimmune disorder against parietal cells and so loss of intrinsic factor
What are the kinds of Neural tube defects?
Anencephaly, Encephalocele, and Spina bifida.
What are the pathological findings for Anencephaly?
The absence of a major portion of the brain, skull, and scalp that occurs during embryonic development and underdeveloped hypothalamus. Results from a neural tube defect that occurs when the anterior neuropore of the neural tube fails to close, usually between the 23rd and 26th day following conception. Frog-like facies; always fatal. (Folic acid supplementation)
What are the pathological findings for Encephalocele?
Encephalocele, is a neural tube defect characterized by sac-like protrusions of the brain and the membranes that cover it through openings in the skull. These defects are caused by failure of the hindbrain neuropore in the neural tube to close completely during fetal development. Usually occipital, rarely anterior at the bridge of nose.
What are the pathological findings for Spina bifida?
Spina bifida is caused by the incomplete closing of posterior neuropore of the embryonic neural tube. Some vertebrae overlying the spinal cord are not fully formed and remain unfused and open. If the opening is large enough, this allows a portion of the spinal cord to protrude through the opening in the bones.
When subarachnoid space is small, the membranous ring is narrow and the neural plate hardly protrudes in Spina bifida is refer to as what?
Myelocele
When subarachnoid space is very large, the membranous ring is wide and neural plate is elevated in Spina bifida is refer to as what?
Myelomeningocele
What are pathological findings for Craniorachischisis?
Craniorachischisis is a severe form of neural tube defect in which both the brain and spinal cord remain open to varying degrees. Failure closing of Closing 1.
What are the pathological findings for Myelomeningocele?
Herniation of malformed cord and meninges through vertebrae defect. Usually with Chiari malformation and hydrocephalus.
Spina bifida Occulta presents what pathological finding?
Sacral dimple
Describe Holoprosencephaly and its clinical findings?
Cerebral hemispheres fail to separate. Clinical findings are cyclopia (cyclop), proboscis (elongated appendages), agnathia (absent of lower jaw), and cleft lip/palate
Common causes for holoprosencephaly is?
TORCH infections, fetal alcohol syndrome, and trisomy 13.
Describe Agenesis of corpus callosum (ACC).
Failure of the axons to form the corpus callosum or cross it.
Cortical development in Neuronal migration defects (NMDs) entails?
- generation of stem cells
- differentiation into neurons/glia
- migration to cortex
- organization into functional layers
In NMDs, neurons that do not migrate at all from the ventricle is called?
Periventricular heterotopia
In NMDs, neurons that migrate half way from the ventricles is called?
Subcortical band heterotopia
In NMDs, some neurons reach cortex and some do not form normal cortical layers is refers to as?
Lissencephaly
Pachygyria
Cobblestone cortex
In NMDs, neurons that over-shoot in the cortex and end up in the subarachnoid space can be refers to as?
Marginal-leptomeningeal heterotopia
Cobblestone cortex
In NMDs, late stage of migration and cortical organization of neurons is disrupted is called?
Polymicrogyria
What clinical findings are associated with Lissencephaly?
Cortical sulci are absent except for the Sylvian fissure. The cortex is thick but has only three neuronal layers.
What pathological findings are associated with Chiari I Malformation?
Chronic protrusion of cerebellar tonsils below the foramen magnum. Some develop hydrocephalus and most patients are asymptomatic.
What pathological findings are associated with Chiari II Malformation?
Cerebellar tonsillar herniation Small posterior fossa Kinked medulla (z-formation) Myelomeningocele Hydrocephalus
What is Dandy-Walker Malformation
Malformation consist of agenesis of cerebellar vermis. Cystic dilation of 4th ventricle/enlargement of posterior fossa.
What are two kinds of neurogenesis disorders (disorders of brain size)
Microcephaly and Megalencephaly
What is a possible diagnosis when the brain is hard to touch or feel like a potatoes with candle guttering in caudate nucleus. Clinical findings involve butterfly distribution of acne on the face but not refer to as acne.
Tuberous sclerosis
What are pathological findings in Polymicrogyria
More cell growth in the fold of the cortical cortex with lead to bigger gray matter with more neuron than white matter.
What happens in metabolic disorders
metabolic abnormalities block amino acid, carbohydrate or lipid metabolism, or impair oxidative phosphorylation
Most inherited metabolic disorders are categorized as what?
autosomal recessive disorders
What are the major categories of inherited metabolic disorders
Lysosomal (most common)
Peroxisomal
Mitochondrial
Amino acid disorders
What is the gray matter inherited metabolic disorder
Lysosomal/Peroxisomal (neuronal storage) diseases
What is the white matter inherited metabolic disorder
Leukodystrophies
What is the inherited metabolic disorder associated with neurons
Mitochondrial encephalomyopathies
Describe the three general principles of Lysosomal storage disorders
Deficiencies of lysosomal enzyme function caused by mutant enzyme proteins and cofactors.
Accumulation (storage) of undegraded products in lysosomes
Causes ballooning, cellular dysfunction, and cell death; the stored products are membrane-bound
what are the five Putative mechanisms of disease in LSDs
Altered trafficking of molecules through lysosomal network.
inflammatory response, through activation of microglia
Oxidative stress
Disruption of autophagy
Initiation of apoptosis
What are the initial signs of Tay-Sach disease
arrest of development, neurologic regression, blindness, and seizures. Inexorable progression leads to vegetative state
Describe the gray matter pathology in Tay-Sach disease
Storage causes neuronal ballooning and torpedo-like swellings of proximal axons and dendrites.
This leads to loss of neurons and their axons
Describe the white matter pathology in Tay-Sach disease
myelin is not primarily affected. Storage in retinal ganglion cells causes blindness.
what is the Laboratory diagnosis of LSDs in Tay-Sach
The gold standard is enzyme assay. Gene analysis is useful for carrier detection
Describe Peroxisomal disorders
Peroxisomes use O2 to generate hydrogen peroxide via peroxidase. H2O2oxidizes/detoxifies ethanol and other toxins
What do peroxisomal enzymes do
catalyze plamologen syntheis and very long chain fatty acid (VLCFA) beta oxidation
What are the two types of peroxisomal disorders
single peroxisomal enzyme deficiencies andperoxisomal biogenesis disorders
what are some manifestations found in peroxisomal disorders
Manifestations include dysmorphic features, liver dysfunction and skeletal abnormalities
What is a key determining biochemical sign of a peroxisomal disorder
elevated VLCFAsanddecreased RBC plasmalogens
What are the clinical findings in the zellweger spectrum
dysmorphic faces, neurologic deficits (hypotonia, decreased sucking, decreased tendon reflexes, seizures, nystagmus), liver disease. Most patients fail to thrive and die by six months of age
What happens in Mitochondrial disorders
when generating ATP , oxygen is converted to free oxygen radicals. These are detoxified by protective enzymes and vitamin antioxidants. If not, free radicals damage lipids, proteins, and nucleic acids
What is a cause of amino acid metabolism disorders
Defective conversion of the amino group to urea, and many of the organic acidemias, which are caused by defects in disposal of the carbon skeletons of branched chain amino acids.
What are the clinical findings of Amino acid disorders
fatal metabolic encephalopathy due to accumulating amino acids, hyperammonemia, impaired energy and synthetic pathways, and defective synthesis of glutamate,
Respiratory depression, seizures, and HIE
What age group are Amino acid disorders typically found in
Most present in the neonatal period with severe or fatal metabolic encephalopathy
Which metabolic disease category presents with hyperammonemia?
Amino acid (urea cycle)
Which metabolic disease category presents with failure to thrive (short stature, muscle weakness, deafness)
Mitochondrial
Which metabolic disease category presents with big livers?
Lysosomal or Peroxisomal
Name one of Angelina Jolie’s kids (don’t google it)
Shiloh, Knox, Vivienne, Maddox, Pax, Zahara
Describe type 1 muscle fibers
protracted slow action fibers
Describe type 2 fibers
capable of fast, powerful contraction
Muscle disease is divided into myopathy and denervation atrophy. Describe myopathy.
Primary disease of muscle. Includes muscular dystrophies and inflammatory myopathies
Muscle disease is divided into myopathy and denervation atrophy. Describe denervation atrophy
Often causes distal weakness and atrophy.
Why do our muscles shrink/die as we age?
Because our nerves that provide muscles with growth factor die off
Describe histology of myopathy
necrosis/phagocytosis and regeneration. Atrophic fibers are scattered among normal or hypertrophic fibers.
What is nuclear change
test question
displacement of nuclei from periphery of fibers to the central zone
What is polymyositis?
think of the name
too many inflamed muscles
What is the most severe of the muscular dystrophies?
Duchenne’s muscular dystrophy
