16-1 CNS and Musclerename
q123456's version from 2016-06-01 18:44
|Leukodystrophies||inherited dysmyelinating diseases in which the clinical symptoms derive from abnormal myelin synthesis or turnover|
metachromatic leukodystrophy, krabbe disease
|broca's and wernicke's||middle cerebral artery (MCA)|
inablity to produce language: speak or write>>broca's-->Expressive aphasia (***dysarthria: inability to move the muscles of the tongue)
Patient is aware of their problem
Inability to repeat phrases/understand language/read/write
speaks in long meaningless speech inablilty to use correct words to express the thoughts.
Patient is unaware of his problem
***the region of the temporal lobe also contain fibers of the visual radiations traveling to the the primary visual cortex.>>>also present with right upper quadrantanopia
2)methylmalonyl-CoA to succinyl-CoA by mutase
1 degeneration of the spinal cord>>>unstable gait, vibration sense is decreased over the lower extremities.
2 anemia>>>dyspnea, pallor and fatigability/Increased serum methylmalonic acid level
|Degenerative diseases of the CNS||alzheimer|
|frontotemporal dementia||atrophy of frontal&temporal lobes at early 50s|
|creutzfeldt jakob disease||infective prions(misfolded protein)>>>resistant to proteases, conversion of normal PrP to proteases resistant PrP|
Bubble and holes spongiform change in gray matter
|Alzheimer disease (AD)||beta amyloid Aβ, positive with Congo red and apple-green birefringence with polarization|
*Aβ is created when the transmembrane protein amyloid precursor protein (APP) is cleaved by β-amyloid converting enzyme and γ-secretase
chromosome 21>>>Down syndrome
most common cause of dementia in the elderly population.
cortical atrophy, plaques and neurofibrillary tangles, dilation of ventricles. MOST in the temporoparietal lobes and hippocampus, Occipital lobe is usually spared
risk factor: age, apolipoprotein E called ε4 (ApoE4).
bilateral abducens palsy
chronic alcoholics (thiamine def)>>>atropy (loss of) cerebellar vermis and purkinje cells in the anterior lobes>>>gait and ataxia
glucose infusion must be accompanied by the admistration of thiamine since thiamine is a cofactor of enzymes responsible for glucose metabolism, infusion of glucose will exacerbate the preexisting thiamine deficiency, precipitating wernicke encephalopathy.
the role of ethanol in CNS: Increased GABA. withdrawal symptoms: shakes, tremor
|malformation:defect||A structural defect due to abnormal embryonic or fetal development. |
cleft lip and cleft palate.
|deformation: change||A change from the normal size or shape due to mechanical forces|
|virus infection CSF||Normal glucose, elevated protein and lymphocytic pleocytosis|
|tension headache (bilateral)||female, under stress, bilateral, muscle tenderness in the head/neck/shoulders|
|cluster headache (one side)||one side headache+nasal congestion+eye tearing|
headache, male, during sleep, behind one eye
The trigeminal nerve causes the eye pain associated with? Cluster headache
|HSV-1||temporal lobe involved encephalitis|
|lock in||central pontine myelinolysis: rapid correction of chronic hyponatremia -->|
osmotic demyelination of the pons. 2-3 days after hyponatremia is corrected, difficulty speaking/swallow
large lesion in the brain stem (the base of the pons)
thrombotic stroke to the basilar artery
|Measles subacute sclerosing panencephalitis||kids+immigrated to the US|
RNA virus in brain>>>hemagglutinin
|normal pressure hydrocphalus NPH||distinguish normal pressure hydrocphalus (NPH) from Alzheimer: |
the order of symptoms are important>>>gait disturbance+urinary incontinence>>>progressive demetia and emotional blunting
symmetrically enlarged ventricles>>>disrupts the periventricular pathways that transmit impulses from the cortex to the sacral micturition center>>> lack of inhibition from the cerebral cortex >>>frequent and uncontrolled micturition or urge incontinence>>>patient has no sensation of bladder fullness and no control over bladder function
|Guillain-Barré syndrome||acute demyelinating disorder|
motor axons that results in ascending weakness that may lead to death from failure of respiratory muscles over a period of only several days
triggered by an infection (Campylobacter jejuni) or a vaccine, the most common lifethreatening diseases of the peripheral nervous system
Treatments include plasmapheresis (to remove offending antibodies)
intravenous immunoglobulin infusions (which suppress immune responses through unclear mechanisms)
supportive care, such as ventilatory support.
|Diabetes||thickness, hyalinization and narrowing of the walls of the arteries|
hyperglycemia in peripheral nerve>>>increased cell osmolarity>>>facilitates water influx into the cell>>>osmotic damge to axons and schwann cells
changes in bowel, bladder, cardiac, or sexual function.
asymmetric pain that can progress to lower extremity weakness and muscle atrophy.
distal symmetric sensorimotor polyneuropathy:
1 paresthesias and numbness in diabetes
2 the most common form of diabetic neuropathy.
3 causes a decreased ability to move or feel because of nerve damage
unilateral CNIII >>>
acute onset diplopia"down and out" position
Diabetes: the most common cause of peripheral neuropathy
|intracranial mass stain positive for synaptophysin:||the neoplastic cells originate from neurons not astrocytomas|
|amyotrophic Latearal sclerosis||upper and lower motor neurons|
|Myasthenia Gravis||autoantibodies that block the function of POSTsynaptic acetylcholine receptors at motor end plates, which results in the degradation and depletion of the receptors.|
ptosis or diplopia
anti-acetylcholine receptor antibodies
hyperplasia of intrathymic B cells (thymic hyperplasia) and thymom
|Lambert eaton syndrome||lung carconoma, |
autoantibodies against PREsynaptic calcium channels (voltage gated ion channels)>>>reduces the release of acetylcholine into the synaptic cleft.
ptosis in small cell lung carcinoma
weakness/swallow difficulty/vision problem
|spina bifida occulta:||myelomeningocele: the spinal cord and meningeal membranes protrude through the opening|
spina bifida occulta: the spinal nerves usually aren't involved
Meningocele: the vertebrae develop normally, but the meninges are forced into the gaps between the vertebrae.
|myelin||peripheral myelin is made by Schwann cells|
CNS myelin is made by oligodendrocytes
each Schwann cell in a peripheral nerve provides myelin for only one internode KA36-22, while in the CNS, many internodes are created by processes coming from a single oligodendrocyte
|ischemic neuronal change||liquefactive necrosis: thrombosis or embolism>>>irreversible ischemic changes in the neurons>>>release of lysomomal enzymes>>>degradation of the tissue>>>phagocytic cells migrate into the area and remove the necrotic tissue>>>leave a cavity/astrocytes proliferate (gliosis)|
first 12 hours: red neurons, edema, swell
up to 48hours: neutrophilic emigration
2-3weeks: mononuclear phagocytic cells
embolic infarctins of brain: Atheromatous plaques within the carotid A and aortic arch, myocardial dysfuntion, valvular disease and AF
the most susceptible neurons to ischemic hypoxic injury? hippocampus and neocortex and Purkinje cells of the cerebellum.
ischemic hypoxic injury: Neurons are more susceptible to hypoxic injury than are glial cells
irreversible neuronal damage and death: astrocytes proliferate at the site of injury (astrocytosis or gliosis)
|Parkinsonism||Depigmented substantia nigra>>>Causes deficiency of dopamine|
Pallidotomy:destroy globus pallidus
CT: KA22-6, 23-22
lewy body: round, eosinophilic and intracytoplasmic inclusions
|Friedreich ataxia||GAA, chr 9, AR|
spinal cord atrophy ( The first symptom to appear is usually gait ataxia, or difficulty walking. The ataxia gradually worsens and slowly spreads to the arms and the trunk. There is often loss of sensation in the extremities) KA36-28
gracile and cuneate nuclei within dorsal root ganglia-
associated with hypertrophic cardiomyopathy
|Huntington disease (HD)||KA 34-9|
degeneration of the striatum (caudate and putamen). CT image
ventricles are dilated and atrophy of the caudate nucleus
loss of GABA containing neurons>>>decreased GABA in the brain
|Degenerative diseases of the CNS||atrophy of temporoparietal lobes and hippocampus>>>alzheimers's|
atrophy of caudate, putamen, globus pallidus>>>huntington disease
depigmentation of substantia nigra (CT image)>>>parkinsonism
atrophy of spinal cord>>>friedreich
widespread neuronal loss and gliosis in subcortical sites with sparing of the cerebal and cerebellar cortices>>>progressive supranuclear palsy: ophthalmoplegia, pseudobulbar palsy, axial dystonia and bradykinesia
|multiple sclerosis||Facial lesions (adenoma sebaceum), |
hypopigmented "ash leaf spots" on skin *NF1: Cafe-au-lait spots (pigmented)
cortical & retinal hamartomas,
seizures, mental retardation,
renal cysts and renal angiomyolipomas,
10 year old boy, epilepsy, mental retardation, ovoid hypopigmented areas on the trunk, a red, yellow papules on the face and mouth (angiofibromata)
the most common of the demyelinating disorders
not hereditary, immune related (cell mediated response against white matter antigens), VITAMIN D related!!!
exacerbations and remissios over many years
e.g a 60 year old woman dies from a chronic progressive neurologic disease characterized by multiple periods of exacerbation and remission.
white matter of CNS oligodendrocyte depletion>>>reduced saltatory conduction
|Duchenne and Becker Muscular Dystrophy||X chromosome, |
Progressive replacement of muscle tissue by fibrosis and fat
causes dilated cardiomyopathy!!!
|Myotonic dystrophy||Abnormally slow relaxation of muscls>>>difficulty loosening one's grip after a handshake or inability to release the doorknob lately|
the dystrophia myotonica protein kinase (DMPK) mutation
CTG repeats in the non coding region of DMPK
most common of muscular dystrophy in adult
prolonged muscle contractions not able to relax after use
Manifests in late childhood with gait abnormalities due to weakness of foot dorsiflexors, with subsequent progression to weakness of the intrinsic muscles of the hands and wrist extensors, atrophy of the facial muscles, and ptosis
|hypertensive arteriolar sclerosis||internal capsule|
|Dermatomyositis||the most common inflammatory myopathy in children|
red rash+ muscle weakness (starts in the neck and arm)
|Mitochondrial myopathies||maternal inheritance, proximal muscle weakness and ocular musculature|
anterior cerebral artery
Medial portion of the temporal lobe
cranial nerve III
Eye is deviated down and out.
Pupil is mydriatic (dilated)
displacement of the cerebellar tonsils through the foramen magnum.
it causes brain stem compression and compromises vital respiratory
and cardiac centers in the medulla.
|Tuberous sclerosis||AD, hamartomas|
biconvex or lens shape hyperdense lesion
do not cross suture lines on CT>>>Epidural hematomas
rupture of the middle meningeal ARTERY
skull fractures>>>epidural hemorrhage
superior cerebral veins (“bridging veins”).
anterior communicating artery>>>berry aneurysms in the circle of wilis
subarachnoid bleeding>>> severe headache, berry aneurysms
subarachnoid hemorrhage: arterial vasospasm several days after the initial insult
|CNS Tumors||"fried egg" tumor cells|
2) Seminoma testicular tumor
3) pineal germinomas
"psammonma body" tumors
2) papillary thyroid
3) serous papillary ovarian
meningioma: psammonma body
ependynoma: canals and pseudorosettes
|glial tumors||astrocytomas, |
|Oligodendroglioma||"fried egg" cells, spherical nuclei surrounded by a clear halo of cytoplasm (Seminoma testicular tumor)|
|CNS Tumors in adults||Glioblastoma(high grade astrocytoma)|
Loss-of-function mutations in the p53 and Rb tumor suppressor pathways
gain-of-function mutations in the oncogenic PI3K pathways
Bizarre pleomorphic tumor cells
necrosis and hemorrhage
Meningioma "psammoma body"
Arise from arachnoid meningothelial cells.
Meningothelial cells of the arachnooid membrane,
NF2 and radiation history
compression of adjacent brain structures,
new-onset serzures/personality changes
Ependymoma: "canals and pseudorosettes"
can form embryologic ependymal canal and pseudorosettes
near the ventricular system.
|CNS Tumors in children||in the posterior fossa in kids|
Astrocytoma and meulloblastoma
Pilocytic Astrocytoma "bipolar"
activating mutations in the serine-threonine kinase BRAF
bipolar cells with long, thin hair like processes ,
Spindle cells/rosenthal fibers/granular eosinophilic body in cerebellum
gait instability/ataxia (cerebellum)
posterior fossa mass
small cells with little cytoplasm and hyperchromatic nuclei, mitoses are abundant
|Germinoma||germ cell |
pineal germinomas: the most common tumor of the pineal gland
resembles testicular seminoma "fried egg">>>facial hair growth, enlarged genitalia, pubic hair growth
impaired upward gaze (parinaud syndrome)
|brain tumor -markers||neurons, neuroectodermal and neuroendocrine cells: SYNAPtophysin |
gliomas: Glial fibrillary acidic protein (GFAP)
neural crest cells: melanocytes and schwann cells: s100+
schwann cells: spindle cells with regular oval nuclei.
|CNS Metastatic tumors||The most common primary sites are lung, breast, skin (melanoma), kidney, and gastrointestinal tract|