NEURO - PATH Flashcards
Parkinson disease
AD - Degenerative disorder of CNS
Lewy bodies (composed of α-synuclein—intracellular eosinophilic inclusions A )
loss of dopaminergic neurons (ie, depigmentation) of *substantia nigra pars compact.
Parkinson TRAPS your body: Tremor (pill-rolling tremor at rest) Rigidity (cogwheel) Akinesia (or bradykinesia) Postural instability Shuffling gait
Huntington disease
AD trinucleotide repeat (CAG) disorder on chromosome 4
INC dopamine, DEC GABA, DEC ACh
characterized by choreiform movements, aggression, depression, dementia
Atrophy of caudate and putamen with hydrocephalus ex vacuo
Expansion of CAG repeats (anticipation).
Caudate loses ACh and GABA.
Osmotic demyelination
syndrome
(Central Pontine Myelinolysis)
Acute paralysis, dysarthria, dysphagia, diplopia,
loss of consciousness.
Can cause “locked-in
syndrome.”
Massive axonal demyelination in pontine white matter 2° to osmotic changes.
caused by overly rapid
correction of hyponatremia
“From low to high, your pons will die” (osmotic demyelination syndrome)
“From high to low, your brain will blow” (cerebral edema/herniation)
Poliomyelitis
Caused by poliovirus (fecal-oral transmission)
Infection causes destruction of cells in anterior horn of spinal
cord (LMN death).
Signs of LMN lesion: weakness, hypotonia, flaccid paralysis, fasciculations, hyporeflexia, muscle atrophy.
Signs of infection: malaise, headache, fever, nausea, etc.
CSF shows WBCs and slight of protein (with no change in CSF glucose).
Friedreich ataxia
Autosomal recessive trinucleotide repeat
disorder (GAA)n on chromosome 9 in gene
that encodes frataxin (iron binding protein).
Leads to impairment in mitochondrial functioning
Presents in childhood with
*kyphoscoliosis
Degeneration of multiple spinal
cord tracts–>muscle weakness and loss of DTRs, vibratory sense, proprioception.
*Staggering gait, frequent *falling, nystagmus, dysarthria, pes cavus, hammer toes, *diabetes mellitus, *hypertrophic cardiomyopathy (cause of death).
Friedreich is Fratastic (frataxin): he’s your favorite frat brother, always staggering and
falling but has a sweet, big heart.
Ataxic *GAAit
Brown-Séquard syndrome
Hemisection of spinal cord
-Ipsilateral UMN signs *below level of lesion (due to corticospinal tract damage)
-Ipsilateral loss of tactile, vibration, proprioception sense *below level of lesion (due to dorsal column damage)
- Contralateral pain and temperature loss *below level of lesion (due to spinothalamic
tract damage)
- Ipsilateral loss of all sensation *at level of lesion
- Ipsilateral LMN signs (eg, flaccid paralysis) *at level of lesion
If lesion occurs above T1, patient may present with ipsilateral Horner syndrome due to
damage of oculosympathetic pathway.
Glaucoma
Optic disc atrophy with characteristic cupping (thinning of outer rim of optic nerve head versus normal), usually with elevated intraocular pressure (IOP) and progressive peripheral visual field
loss if untreated.
Treatment is through pharmacologic or surgical lowering of the IOP.
Open-angle glaucoma
Associated with age, African-American race, family history.
Painless, more common in US.
Primary—cause unclear.
Secondary—blocked trabecular meshwork from WBCs (eg, uveitis), RBCs (eg, vitreous
hemorrhage), retinal elements (eg, retinal detachment).
Closed- or narrow-angle
glaucoma
Primary—enlargement or forward movement of lens against central iris–>*obstruction of normal aqueous flow through pupil–>fluid builds up behind iris, pushing peripheral iris against cornea and *impeding flow through trabecular meshwork.
Secondary—*hypoxia from retinal disease (eg, diabetes mellitus, vein occlusion) induces
vasoproliferation in iris that *contracts angle.
Chronic closure—often asymptomatic with damage to optic nerve and peripheral vision.
Acute closure—true ophthalmic emergency. IOP pushes iris forward–>angle closes abruptly.
Very painful, red eye D, sudden vision loss, halos around lights, rock-hard eye, frontal headache.
Do not give epinephrine because of its mydriatic effect.
Conjunctivitis
Inflammation of the conjunctiva red eye
Allergic—itchy eyes, bilateral.
Bacterial—pus; treat with antibiotics.
Viral—most common, often *adenovirus; sparse mucous discharge, swollen preauricular node; self-resolving.
Alzheimer disease
Widespread cortical atrophy. Narrowing of gyro and widening of sulci
Senile plaques in gray matter
Neurofibrillary tangles: intracellular, hyperphosphorylated *tau protein
INC ACh.
ApoE2: DEC risk of sporadic form
ApoE4: INC risk of sporadic form
APP, presenilin-1, presenilin-2: familial forms (10%) with earlier onset
Most common cause in elderly.
Down syndrome patients have an INC risk of developing
Alzheimer
Frontotemporal dementia
Frontotemporal lobe degeneration.
Inclusions of hyperphosphorylated tau (round
*Pick bodies) or ubiquitinated TDP-43.
Early changes in personality and behavior (behavioral variant), or aphasia (primary progressive aphasia).
May have associated movement disorders (eg, parkinsonism, ALS-like UMN/LMN degeneration).
Lewy body dementia
Initially dementia and visual hallucinations (“haLewycinations”) followed by parkinsonian features.
Intracellular Lewy bodies (insoluble aggregates
of α-synuclein) primarily in cortex.
Vascular dementia
Result of multiple arterial infarcts and/or chronic ischemia.
Step-wise decline in cognitive ability with late onset memory impairment.
multiple cortical and/or
subcortical infarcts.
2nd most common cause of dementia in elderly.
Creutzfeldt-Jakob disease
Rapidly progressive (weeks to months) dementia with myoclonus (“startle myoclonus”)
Spongiform cortex.
Prions (PrPc–>PrPsc sheet [β-pleated sheet resistant to proteases]).
Multiple sclerosis
optic neuritis (sudden loss of vision resulting in Marcus Gunn pupils), INO, hemiparesis, hemisensory symptoms, bladder/bowel dysfunction
Charcot triad of MS is a SIN:
Scanning speech
Intention tremor (also Incontinence and Internuclear ophthalmoplegia)
Nystagmus
Relapsing and remitting course.
INC IgG level and myelin basic protein in CSF.
*Oligoclonal bands are diagnostic.
MRI is gold standard. *Periventricular plaques (areas of oligodendrocyte loss and reactive gliosis) with
destruction of axons.
Multiple white matter lesions separated in space and time.
Most often affects women in their 20s and 30s; more common in whites living further from equator.
Acute disseminated (post infectious) encephalomyelitis
Multifocal periventricular inflammation and demyelination after infection (*measles or VZV) or vaccination (rabies, *smallpox)
rapidly progressive multifocal neurologic symptoms, altered mental status.
Charcot-Marie-Tooth
disease
AKA hereditary motor and sensory neuropathy (HMSN).
*most common inherited neuropathy
Group of progressive hereditary
nerve disorders related to the defective production of proteins involved in the structure and
function of peripheral nerves or the myelin sheath.
Typically *autosomal dominant
associated with foot deformities (pes cavus), lower extremity weakness and sensory
deficits.
Krabbe disease
Autosomal recessive lysosomal storage disease due to deficiency of *galactocerebrosidase.
Buildup of *galactocerebroside and *psychosine destroys myelin sheath.
peripheral neuropathy,
developmental delay, optic atrophy, globoid cells.
Metachromatic leukodystrophy
Autosomal recessive lysosomal storage disease, most commonly due to *arylsulfatase A deficiency.
Buildup of *sulfatides–>impaired production and destruction of myelin sheath.
central and peripheral demyelination with ataxia, dementia.
Progressive multifocal
leukoencephalopathy (PML)
Demyelination of CNS due to destruction of *oligodendrocytes.
sx: altered mental status, aphasia, ataxia, hemiparesis/hemiplegia, visual field defects
Seen in 2–4% of AIDS patients
(reactivation of latent *JC virus infection).
Rapidly progressive, usually fatal.
risk associated with
natalizumab, rituximab.
Adrenoleukodystrophy
X-linked genetic disorder typically affecting males.
Disrupts metabolism of very-long-chain fatty acids –>excessive buildup in nervous system, adrenal gland, testes.
Progressive disease that can
lead to long-term coma/death and adrenal gland crisis.
