tumor, headache, dementia, Parkinson Flashcards
Adult primary brain tumors - types
- Glioblastoma multiforme (grade IV astrocytoma)
- Meningioma
- Hemangioblastoma
- Schwannoma
- Oligodendroglioma
- Pituitary adenoma
Meningioma - treatment / histology
resection and/or radiosurgery
- spindle cells concentrically arranged in a whorled pattern
- psammoma bodies (laminated calcification)
Hemangioblastoma - most often area / can produce
cerebellum / erytrhopoietin (2ry polycethemia)
- associated with VHL
Schwannoma stain / treatment
S-100 positive
- resectable or treated with stereotactic radiosurgery
Childhood primary brain tumors - types
- Pilocytic (low grade) astrocytoma
- Medulloblastoma
- Ependymoma
- Craniopharyngioma
- pinealoma
ependymoma can cause / histology
Hydrocephalus
- characteristic perivascular rosettes.
Rod-shaped blepharoplasts (basal ciliary bodies) found near nucleus
craniopharyngioma can cause
- bitemporal hemianopia
- hypopituitarism
- hyperphagia (destruction of ventromedial area - satiety area of hypothalamus)
Medulloblastoma - histology / gross appearance / complications
- Homer-Wright rosettes
- small blue cells
gross: solid
complications: 1. compress 4th ventricle causing hydrocephalus - send “drop metastases” to spinal cord
Pinelioma can cause … (and mechanism)
- Parinaud syndrome: compression of tectum –> vertical gaze palsy
- obstructive hydrocephalus (compression of cerebral aqueduct)
- precosious puberty in males (increased β-HCG production)
headache - definition / MC in (sex)
- pain due to irritation of of structure such as dura, cranial nerves or extracranial structures
- MC in women, except clusters
main types of headache - duration
- cluster –> 15min-3h repetitive
- tension –> more than 30 min (typically 4-6h)
constant - migraine –> 4-72h
Migraine mnemonic
POUND
Pulsatile, One-day duration, Unilateral, Nausea, Disabling
cluster headache - characteristic of pain and other symptoms
- Repetitive brief headaches
- Excruciating periorbital pain with lacrimation
- Rhinorrhea
- may present with HORNER syndrome
cluster headache - treatment
acute: 1. 100% 02 2. sumatriptan
prophylaxis: verapamil
tension headache - treatment
- Analgesics
- NSAID
- acetaminophen
- Amitryptyline for chronic pain
Migraine - treatment
Acute: triptans, NSAIN, dihydroergotamine
ProphylaxiS: lifestyle changes (sleep, exercisem diet eg,) propranolol, topiramate, Ca2+ channel blockers, amitriptyline, valproate
triptans - clinical use
- acute migraine
2. cluster headache attacks
triptans - mechanism of action
5-HT (1B/1D) agonists (seretonin) –>
a. inhibit trigeminal nerve activtion
b. prevent vasoactive peptide release
c. induce vasoconstriction
triptans - toxicity
- coronary vasospasm
2. mild paresthesia
triptans are contraindicated in
patients with CAD or Prinzmetal angina
Menierre disease - symptoms
- recurrent attacks of vertgio (>20 mins)
- tinnitus
- hearing loss
- fullness sensation
familiar form of Alzheimer disease - proportion and proteins
10%
APP, presenilin-1, presenilin-2
Altered proteins - Alzheimer disease
altered proteins:
ApoE2: decreased risk of sporadic
ApoE4: increased risk of sporadic
APP: increased risk for early onset (familiar)
presenilin-1: increased risk for early onset (familiar)
presenilin-2: increased risk for early onset (familiar)
Alzheimer disease - histology
- loss of ach neurons
- senile plaques in gray matter (extracellular β-amyloid (Aβ) core)
- Neurofibrillary tangles (intracellular, hyperphosphorylated tau protein)
Alzheimer disease - senile plaques CAN CAUSE (how)
amyloid angiopathy –> intracranial haemorrhage
deposition around vessels
Lewy body dementia - clinical course
initially dementia and visual hallucinations followed by parkinsonian features
Lewy body dementia - histology
- loss of pigmented neurons in substantial nigra
2. lewy bodies (PRIMARILY CORTICAL)
Lewy bodies
round eosinophilic inclusion of α-synuclein (PRIMARILY CORTICAL)
Frontotemporal dementia (Pick disease) - histology
- silver-staining spherical tau protein aggregates (Pick bodies)
- inclusions of ubiquitinated TDP-43
Frontotemporal dementia (Pick disease) - symptoms
- Dementia
- aphasia (early) (primary progressive aphasia)
- movement disorders (eg. parkinsonism, ALS-like UMN/LMN degeneration)
- early change in personality and behaviour
vitamins deficiency associated dementia - vitamins
Vitamins B1, B3 or B12
Parkinson disease - histology
- Lewy bodies (composed of a-synuclein - intracellilar eosnophilic inclusions)
- loss of dopaminergic neurons of substantia nigra pars compacta (de-pigmentation)
Parkinson disease - neurotransmitter alternations
- decreased dopamine
- increased Ach
- Increased serotonin
Parkinson disease - symproms
MNEMONIC: TRAP
- Tremor (pill-rolling tremor at rest)
- Rigidity (cogwheel)
- Akinesia (or bradykinesia)
- Postural instability
- Shuffling gait
Huntington disease - chromosome of trinucleotide / trinucleotide repeat / age / mode of inference
ch 4
CAG
20-50
AD
Huntington disease - symptoms
- choreiform movements (athetosis, chorea)
- aggression
- depression
- dementia
Huntington disease - neurotransmitter alternations
- increased dopamine
- decreased GABA
- decreased Ach
Huntington disease - MRI
Atrophy of caudate and putamen nuclei with hydrocephalus ex vacuo
Huntungton is sometimes mistaken for
substance abuse
Huntington disease - pathogenesis
neuronal death via NMDA-R binding and glutamate toxicity
neurons cell bodies and dendrites can be seen on
Nissle staining (stains RER)
Injury of axon of neuron –> .. ..
Wallerian degeneration: degeneration distal to injury and axonal retraction proximally –> allows for potential regeneration of axon (if in peripheral)
Myelin is made of
- CNS - oligodendrocytes
- PNS - Schwann cells
astrocytes, microglia, Schwann cells, oligodendroglia - derived from
astrocytes –> neuroectoderm
microglia –> mesodermal, mononuclear origin
Schwann cells –> neural crest
oligodendroglia –> neuroectoderm
correcting of serum Na+ too fast can cause
from low to high –> Osmotic demyelination syndrome
from high to low –> cerebral edema/herniation
Huntington Drugs and mechanims of action
- Haloperidol –> D2 receptor antagonist –
- Tetrabenazine –> VMAT inhibitor
- reserpine –> VMAT inhibitor –> limits dopamine vesicle packagings and release
VMAT: vesicular monoamine transporter
Alzheimer disease - drugs and mechanism of action
- Memantine –> NMDA receptor antagonists –> helps prevent exctitoxicity (mediated by Ca2+)
- Donepezil –> Ache inhibitors
- galantamine –> Ache inhibitors
- rivastigmine –> Ache inhibitors
- tacrine –> Ache inhibitors
Memantine - side effects
- Dizziness
- confusion
- hallucinations
Alzheimer disease - Ache inhibitors - side effects
- nausea
- dizziness
- insomnia
Parkinson disease drug - dopamine agonists (drugs)
- bromocriptine (ergot)
- pramipexole (non-ergot)
- ropinirole (non-ergot)
Parkinson disease drug - increase dopamine availability - drugs and mechanism?
amantadine –> increases dopamine release and decreases dopamine reuptake
amantadine - toxicity
- ataxia
2. livedo reticularis
Parkinson desease drugs - increase L-DOPA availability - mechanism
agents prevent peripheral (pre-BBB) L-DOPA degradation –> increase L-DOPA entering CNS –> increase central L-DOPA available for conversion to dopamine
agents that prevent peripheral (pre-BBB) L-DOPA degradation
- carbidopa
- entacapone (peripheral COMT)
- tolcapone (central and peripheral COMT)
selegiline - clinical use
adjunctive agen to L-dopa in treatment of Parkinson
selegiline - mechanism of action
blocks conversion of dopamine into DOPAC by selectively inhibiting MAO-B
L-dopa to dopamine - enzyme?
DOPA decarboxylase
L-dopa - toxicity
- arrhythmias from increased peripheral formation of catecholamines
- Long term use can lead to dyskenesia following administration (on-off phenomeno), akinesia between doses
Parkinson disease drug - curb excess cholinergic activity - drugs and action
Benzotropine (antimuscarinic) –> improves tremor and rigidity but has little effect on bradykinesia
all Parkinson drugs and mechanism of action (shortly)
- Bromocriptine (dopamine agonist)
- Pramipexole (dopamine agonist)
- ropinirole (dopamine agonist)
- amantadine (incr dopamine release and inh reuptake)
- Levodopa (increases dopamine levels in CNS)
- carbidopa (DOPA decarboxylase inhibitor)
- entacapone(peripheral COMT inhibitor)
- tolcapone (central and peripheral COMT inhibitor)
- selegiline (MAO-B inhibitor) (and rasagilini)
- benzotropine (antimuscarinic)
