neuro diseases Flashcards
7 signs and symp of Freidreich Ataxia
1) progressive ataxia
2) Severe dysarthia
3) loss of position sense
4) impaired vibratory sensation
5) loss of tendon reflexes (with extensor plantar responses)
6) pt usually in a wheelchair by age 5
7) spasticity
what is the nucleotide repeat in freiderich ataxia?
GAA
two major differences between Huntington’s disease and Freidreich Ataxia
- Freidreich ataxia is autosomal RECESSIVE (huntington’s disease is dominant)
- Freidrich ataxia presents in childhood (usually in a wheelchair by age 5) (Huntington’s ave age = 40 yo)
7 yo boy w/ worsening uncoordinate arm and leg mvmt, slurred speech, no family HO neuro/muskuloskeleton disorders, preserved language but gross dysarthria, staggering gait, limited ability to walk unassisted, normal bulk and tone, but strength diminished, patellar and ankle reflexes are absent, vibratin and position sense is impaired. What disease is it and how is it transmitted?
Freidreich ataxia– autosomal RECESSIVE- GAA trinucleotide repeat
what chronic, slowly progressive, multisystem disease characterized by muscle wasting is associated with cataracts and heart conduction deficits?
myotonic dystrophy
An autoimmune disorder resulting in progressive weakness that ascends from the lower extremities, usually after a viral ifxn or other medical condition (like systemic lupus erythematosus and hodgkin disease)
Guillain Barre syndrome
In 98% of the cases, Freidreich ataxia results from a GAA trinucleotide repeat in which gene?
frataxin gene
inflammation localized to a small portion of the spinal cord (lateral corticospinal tracts) or cerebral cortex (precentral gyrus) may occur in…
progressive multifocal leukoencephalopathy (PML) or MS
PML occurs in people who are…
immunosuppresed
classic autoimmune disease involving the NMJ is…
myasthenia gravis- but this mainly affects extraoccular muscles and isolated limb weakness is rare
the MCA provides blood to…
primary motor cortices on lateral aspects of hemispheres —> brainstem (innervating face), spinal cord innervating upper limbs, trunk and proximal part of lower extrem)
The PCA sends blood to…
the occipital cortex
interruption to the PCA would cause
visual deficits rather than paralysis
50 yr old woman w/5 yr HO headaches, generalized tonic-clonic seizures, bilat. leg weakness, skull hyperostosis of calvarium, intracranial mass. microscopic exam shows whorling pattern of cells- most likely diag?
meningioma
meningioma- what are they? what are they made of? what do they look like histologically?
slow growing, benign tumors- 15% of IC (intracranial) tumors, common in elderly. Originate from dura or arachnoid, sharply demarcated from brain tiss. cause an osteoblastic rxn in overlying cranial bones. cells have a tendency to circle one another —> form whorls of psammoma bodies.
how do meningiomas present?
as mass lesions, seizures may occur, produce leg weakness
txt of meningioma?
usually surgical
where do arachnoid cysts usually occur?
sylvian fissure
what is a glioblastoma multiforme?
an aggressive malignant astrocytoma —> would kill pt relatively quickly
oligodendrogliomas
glial tumors that could produce symptoms sim to meningioma (seizures may occur, produce leg weakness) but no hyperostosis or whorling pattern microscopically
microscopically, meningiomas are unique in that they…
form whorls of psammoma bodies
Type I arnold Chiari clinical manifestations- when would they start and what are they?
might start in adolescence or adult life, may include cerebellar ataxia, obstructive hydrocephalus, brain stem compression and syringomyelia
Type II arnold-chiari clinical manifestation- when do they present/what are they?
present in childhood (15% die within 1 year)
- difficulty swallowing (compressed nucleus ambiguus)
- loss of Pain/Temp sensation on back of neck/shoulders (syringomyelia) which interrupts the ascending afferent sensory fibers in spinothalamic tracts
- mental retardation secondary to coincident meningomyelocele
- hydrocephalus due to occlusion of CSF flow thru foramen magnum
Dandy WalkerSyndrome brain features
- cerebellar vermis hypoplasia
- dilation of the 4th ventricle (foramina of Lushka and Magendie don’t open!)
symptoms of Dandy-Walker syndrome
- hydrocephalus (no foramina of luschka or magendie so dilated 4th ventricle)
- ataxia- hypoplasia of vermis
- mental retardation
“Dandy Walker has trouble Walking!”
relative prevalence of arnold-chiari vs Dandy-Walker
arnold chiari = relatively common (esp type I): 1/100
Dandy-Walker: relatively uncommon: 1/25000
hydrocephalus
too much CSF in ventricles
- mt lead to Increased ICP (if brain tissue = compressed/can’t recover —> mt lead to mental retardation)
most common congenital cause of hydrocephalus? What causes that?
aquaductal stenosis (usually caused by maternal ifxn with cytomegalovirus (CMV) or toxoplasmosis)
maternal ifx with cytomegalovirus (CMV) or toxoplasmosis can cause what in the baby?
congenital aquaductal stenosis in the baby —-> hydrocephalus
presentation of hydrocephalus
thinning of skull bones and cerebral cortex
cranial sutures don’t close until several yrs after birth, and ICP pushes bones apart —> bigger head
txt for hydrocephaly
- extraventricular shunt (from ventricle to peritoneum)
- endoscopic 3rd ventriculostomy (opening blockage)
- cauterization of ependymal cells– reduce CSF production
microcephally - what is it and what happens to head size? clinical manifestation?
small brain size —> small head size bc brain growth —> skull growth
- 50%: mental retardation
microcephaly mt be caused by…
- genetic causes
- prenatal ifxn
- teratogen exposure (ETOH, toxoplasmosis, radiation)