Exam 6 (no drugs) Flashcards
Demyelination causes clinical symptoms because of?
Conduction block
Guillain-Barre syndrome
- describe presentation
- diagnosis
- treatment
- can cause death due to to
DEMYELINATING PERIPHERAL NEUROPATHY
- Presentation
- ascending paralysis
- loss of reflexes - CSF Findings
- elevated protein - Treatment
- IVIG
- mechanical ventilation if required - Death due to respiratory failure
Multiple sclerosis epidemiology
- age group
- gender
- hereditary?
- latitude
- 95% in ages 15-50
- 2nd most common cause of neurological deficit in the age group - 2/1 = female/male
- Yes there’s a hereditary component
- Higher risk if spend adolescence in temperate zone
MS lesions tend to cluster in which areas? significance?
Where white matter is in direct contact w/ CSF
Explains the vision loss, walking issues (cerebellum) and bladder dysdx
Why are psychiatric and behavioral changes associated w/ MS?
B/c it hits the frontal lobe
Compare old vs new MS lesions on MR
New/active lesions - contrast enhancement
Old lesions - increased signal on T2 w/out enhancement
Explain internuclear ophthalmoplegia
Bilateral INO pathognomonic for?
Damage to the MLF
-nystagmus when abducting eye on affected side and unable to adduct the opposite eye
Bilateral INO seen in MS due to demyelination of the MLF
List 8 clinical findings associated with MS. (Goljan)
- Sensory dysfx
- UMN dysfx
- including babinski - Autonomic dysfx
- urge incontinence
- sexual dysfx
- bowel motility problems - Optic neuritis
- inflammation of optic nerve
- blurry or sudden loss of vision - Cerebellar ataxia
- Scanning speech (sound drunk)
- Intention tremor (nystagmus)
- Bilateral INO
What test can be used to assess for evidence of primary demyelination/remyelination pathophysiology?
Visual evoked potentials
-delay after remyelination occurs
CSF findings in MS
ALWAYS IMAGE FIRST
- slight pleocytosis (10-15 lymphocytes)
- Elevated CSF index (>0.6) -> too much IgG present in CSF relative to plasma
- Oligoclonal bands
- measure IgG spikes
- compare to serum
- allowed to have one more than what is present in the serum
What’s one thing you should always check for when MS exacerbation is suspected?
INFECTION
Central pontine myelinolysis
- pathophys
- cause by
- increased risk from
- clinical presentation
- imaging
- Path - demyelination of ventral pons
- Caused by rapid correction of hyponatremia
- Increased risk from malnutrition and alcohol
- Locked in state, quadriplegia or even coma
- Imaging
- Increased T2 signal in the pons
- trident sign
PML tends to attack which area of the brain? What sxs are seen? What is the time course?
Posterior areas
Aphasia, visual defects and hemiparesis
Subacute to chronic onset
Diagnosis for PML
- MRI
- CSF
- Serum
- MRI
- non-enhancing
- no mass effects - CSF
- pcr for JCV virus - Serum
- Serum JC antibodies (found in 60-80% of population)
What is IRIS and it’s association with PML?
- Reconstituting immune system leading to intense inflammatory reaction in region of PML
- Can cause herniation
- Seen when AIDS patients put on triple therapy (HAART)
Acute Disseminated Encephalomyelitis
- onset time course
- Follows what?
- how can it lead to death
- MRI findings
- CSF
- Treatment
- Onset
-rapid (hours to days)
headache -> lethargy -> coma - Follows viral infection or vaccination
viral -> express Ag that cross reacts w/ myelin
vaccination -> measles - Death due to cerebral edema and mass effect if not txed
- MRI
- Gadolinium enhancement of white matter
- remember PML is non-enhancing - CSF
- moderate lymphocytic pleocytosis (50-100 cells)
- elevated protein
- oligoclonal bands (less common) - Treatment
- IV methylprednisolone (1000 mg)
- hemicraniectomy may be necessary
Charcot Marie Tooth Disease
- which type of neuropathy?
- progression time?
- rarely complain of?
- inheritance?
- length dependent sensorimotor peripheral neuropathy
- progresses over years to decades
- rarely complain of numbness or tingling
- autosomal dominant
CMT-1 conduction velocity (slow or fast)
compare the 3 types of CMT-1
CMT1 has very slow conduction velocities (dysmyelinating)
CMT1A
- PMP22 duplication
- 75% of all CMT1
CMT1B
-myelin protein zero
20% of all CMT1
CMT1X
- looks like CMT1 but never has male to male inheritance
- connexin 32
CMT-2 conduction velocity (slow or fast)
normal motor conduction velocity
What is the most common hereditary ataxia?
Friedreich’s ataxia
Friedreich’s ataxia
- inheritance
- gene involved and what does it code for
- age group
- sx triad
- other systems associated
- tx
- autosomal recessive
- Frataxin gene deficiency (9q13)
- trinucleotide repeat disorder
- deficiency leads to impaired mitochondrial iron homeostasis
- cells are more prone to apoptosis - Adolescent and young adults - slow onset
- Triad
- absent ankle reflexes (peripheral neuropathy)
- bilateral babinski
- dysmetria (ataxia) - Multisystems
- hypertrophic cardiomyopathy (major)
- diabetes (1:4)
- scoliosis (1:4)
6. Tx –Treat diabetes –Correct scoliosis –Manage hypertrophic cardiomyopathy • vigilant blood pressure control
Suspicion for Huntington’s based on?
Age of onset?
Huntington gene?
MRI findings?
Best test to dx?
How do you tx?
Triad
- psychiatric/cognitive probs
- chorea
- dominant inheritance
Age
5-70 (usually 25-45)
Huntington gene (expanded GAG repeats; chromosome 4)
MRI - caudate atrophy/diffuse atrophy
-these occur later
GENETIC TESTING IS BEST
Treatment
-Atypical and traditional antipsychotics can help
psychosis, SSRIs depression, anxiolytics for anxiety
-No treatment effective for primary process
ALS
- clinical presentation
- what’s spared
- inheritance?
- cognition?
- pathogenesis
- dx
- treatment
- clinical presentation
- UMN and LMN signs
- usually starts in intrinsic muscles of the hands - sensation, bladder/bowel fx and eye control are spared!
- 5-10% dominantly inheritance
- Cognition spared but subset have frontotemporal dementia
- Mutated or misfolded SOD1 leading to apoptosis of neurons
- Dx of exclusion
- MRI
- EMG
- FVC - Treatment
Riluzole - glutamate antagonist
What is the safety margin percentage beyond which patients with alzheimer’s start to display symptoms
20%
List all the histological changes associated with Alzheimer’s. What location do you expect these changes to occur? (be able to recognize the image)
Cerebral cortex and hippocampus
- neuritic plaques
- neurofibrillary tangles
- granulovacuolar degeneration
- congophilic angiopathy: beta amyloid
- Hirano bodies
The Pittsburgh compound binds to what? How is it visualized?
Binds to amyloid deposits
Visualized on PET scan
Frontotemporal lobar degeneration often initially presents with what? Often misdxed as?
Late stage sxs?
EARLY
Personality and behavior changes
-Misdxed as psychiatric disorder
LATE
- gradual reduction in speech
- akinesia and rigidity
Highlight some of the differences b/w (there are 2)
FTD
- earlier onset compared to AD
- at an early stage, do not cause the memory loss and visuo-spatial disorientation that are so characteristic of AD
What cortical areas are affected with FTD (there are 5)
- ACC
- Frontal insula
- Frontal pole
- Orbitofrontal cortex
- Temporal pole
Pick’s disease
- age of onset
- inheritance
- clinical course
- area of brain affected
- compensatory mechs
- tx
- age around 60
- sometimes autosomal dominant
- clinical course 2 - 5 years (dead)
- Extreme frontotemporal atrophy (knife like gyria)
- compensatory hydrocephalus
- no tx
Huntington’s disease
- inheritance
- age range
- late manifestations (decade of life)
- early changes
- late changes
- Inheritance
- autosomal dominant - Age range
- 20 to 50 - Late manifestations
- 4th to 5th decades - Early changes
- personality and depression - Choreiform movements, jerking and dementia
Huntington’s genetics
- which chromosome affected
- type of mutation
- chromosome 4
- expanded unstable trinucleotide (CAG) repeat -> more repeats = earlier onset of disease
Which regions of the brain are damaged in Huntington’s?
What’s the structural consequence of these changes?
Marked atrophy of the caudate nucleus
- loss of small to medium sized neurons
- fibrillary gliosis (astrocytosis)
Putamen and cortical atrophy
-variable
Ex vacuo dilations of the anterior horns of lateral ventricles
ALS
- UMN or LMN?
- Males vs females
- age
- breakdown of sporadic vs familial
- Which chromosome (what does it code for)
- Both UMN and LMN
- UMN -> prefrontal cortex
- LMN -> CN nuclei and anterior horn cells of SC - Males > females
- Age > 40
- 90% sporadic; 10% familial
- Chromosome 21q
- codes for superoxide dismutase
- toxic action of mutated enzyme -> decreased zinc binding capacity
ALS clinical presentation
Initial presentation - asymmetrical weakness
LMN: muscle atrophy, weakness, fasciculations
UMN: weakness and spasticity
Progressive w/ loss of all voluntary movement; death from respiratory failure or sepsis
Intellect unimpaired
ALS variants
- progressive bulbar palsy
- progressive muscular atrophy
- primary lateral sclerosis
- Cranial nerve involvement
- dysarthria, dysphagia and respiratory compromise - Predominant LMN involvement
- spinal cord anterior horn involvement - Confined to the corticospinal tract
- UMN
Friedreich’s ataxia
- inheritance
- mutation (which chromosome/type)
- function of the gene
- autosomal dominant
- Chromosome 9
- trinucleotide (GAA) expansion on gene coding for frataxin
- results in low levels of the protein
- frataxin plays a role in iron homeostasis in the mitochondria
- get mitochondrial iron accumulation
- cells are more prone to apoptosis
Friedreich’s ataxia
-sites of degeneration (from goljan = 5)
- DRG
- Posterior columns
- Spinocerebellar tracts
- lateral corticospinal tracts
- large sensory peripheral neurons
Friedreich’s ataxia
-clinical findings (5)
- progressive
- gait ataxia to ataxia of all extremities
- loss of tendon reflexes, cerebellar dysarthria
- impaired joint position, vibration
- pes cavus: arches feet, claw toes
Friedreich’s ataxia
-associated with (from goljan = 2)
- hypertrophic cardiomyopathy
- DM1 (10%)
What is the most useful diagnosis for CJD?
EEG - Slow (1-2 cycles/sec) generalized triphasic periodic sharp wave complexes
How does FLAIR MRI work? What is it good for?
- facilitates the visualization of ABNORMAL parenchymal water content resulting from pathology
- great for edema generating pathology and white matter lesions (such as MS)