Neuro Flashcards
Picks Disease
- atrophy of frontal and temporal lobes
- pick bodies (cytoplasmic inclusions of tau)
- personality and behavioral change (inappropriate behavior)
- autosomal dominant
Alzheimer Disease
- generalized brain atrophy
- neurofibrillary tangles
- amyloid plaques
- chromosome 21
- apo E4 inc. risk (apo E2 dec. risk)
- dec. choline acetyltransferase activity in nucleus basalis
Tx for Status Epilepticus
- Give benzodiazepine (lorazepam) to stop seizure and simultaneously give phenytoin to prevent seizures (blocks Na channels)
- If still seizing, give barbiturate or place under general anesthesia
Scotoma
Visual field defect that involves parts of the retina or the optic nerve causing a discrete area of altered vision surrounded by zones of normal vision.
Lesions of macula cause central scotomas.
Pilocytic Astrocytoma
Cystic tumor in cerebellum of child. Biopsy shows spindle cells with hairlike processes associated with microcysts. These are mixed with Rosenthal fibers and granular eosinophilic bodies.
-most common brain neoplasm of childhood
Disdiadokokinesia
Inability to perform rapid, alternating movements.
Epidural Hematoma
Lucid interval followed by LOC.
Due to tear of middle meningeal artery.
Located between bone and dura mater, lens shaped
Charcot Bouchard Aneurysms
Cause: HTN
Location: basal ganglia, cerebellum, thalamus, pons
Size:
Inhibitory Neurotransmitters
- glycine
- gamma-aminobutyric acid (GABA)
Neurophysins
Carrier protein for vasopressin and oxytocin.
What cells secrete aqueous humor in the eye?
Ciliary Epithelium
This is inhibited by nonselective beta blockers and carbonic anhydrase inhibitors
What cells does the immune system attack in MS?
Oligodendrocytes (secrete myelin)
What cells secrete myelin in the PNS?
Schwann cells, which are targeted by the immune system in ALS.
Waterhouse Friedrickson
-N. mening leads to sepsis, leads to DIC, leads to adrenal infarct
Tau Protein Diseases
- Alzheimers
- Picks
a-Synuclein Diseases
- Lewey Body Dementia
- Parkinsons
Apolipoprotien
- Alzheimers
- E2 is protectice
- E4 is inc. risk
SOD1 Gene Mutation
-ALS
GFAP
- glial fibrillary acidic protein
- tumor marker of glial neuron support cells (ie astrocytes)
Rosenthal Fibers
-pilocytic astrocytoma
Subdural Hematoma
- rupture of cortical bridging veins
- banana shaped
- gradual HA and confusion
Pineal Gland
- located behind third ventricle
- in charge of sleep and heat cycles in animals
- germinoma makes HCG if you have a tumor and can cause vertical gaze palsy and N/V
What signifies a complex seizure?
- characterized by loss of memory during the event
- compared to simple where memory is maintained
Schwannomas
- tumor of peripheral nervous system (can still be in cranium)
- antoni A, antoni B, verocay bodies
- S100+
- may arise on any cranial nerve (except CN 2)
- most common site is cerebellopontine angle at CN 8 (acoustic neuromas)
What effect does pCO2 have on cerebral vasculature?
- pCO2 is a potent vasodilator of cerebral vasculature
- inc. breathing rate causes dec. pCO2 and causes cerebral vasoconstriction > dec. cerebral blood flow and dec. cerebral intracranial pressure
Open Angle Glaucoma
- inc. intraocular pressure due to inc. secretino of dec. outflow of aqueous humor
- progressive loss of peripheral visual fields
- chronic
- painless
Closed Angle Glaucoma
- acute
- painful
- sudden rise in intraocular pressure
Drug of Choice for Status Epilepticus
- benzodiazepines
- inc. effect of GABA-A receptor > inc. influx of Cl- > hyperpolarization
Length Constant
- also called space constant
- measure of how far along an axon an electrical impulse can propagate
- dec. in MS
Flame Shaped Retinal Hemorrhages
- caused by sever HTN in retinal precapillary arterioles
- cause painless, unilateral visual disturbances
- causes fibrinous necrosis
Cauda Equina Syndrome
- compression of spinal cord nerve roots below conus medullaris
- pts presents with bilateral radicular pain, saddle anesthesia, and hyporeflexia
- bowel and bladder incontinence are late manifestations
Acute Dystonic Reaction
- extrapyramidal symptoms due to antipsychotic medications
- sudden involuntary contraction of a major muscle group
- due to D2 antagonism in the nigrostriatal pathway
Signs of Shaken Baby Syndrome
Subdural hemorrhage and retinal hemorrhage.
What part of CN 3 is damaged first in diabetic neuropathy?
Central somatic fibers are affected before peripheral parasympathetic fibers.
Sx: ptosis, down and out gaze, but normal accommodation and rxn to light
Essential Tremor Tx and Characteristics
- AD
- symmetric tremor that inc. when holding one position
- improves with alcohol consumption
- tx: non-selective beta blocker
Function of Ventromedial Hypothalamic Nuclei
- mediates satiety
- destruction causes hyperphagia and obesity
Function of Lateral Hypothalamic Nuclei
- mediates hunger
- destruction leads to anorexia (you shrink laterally)
Function of Anterior Hypothalamic Nuclei
- mediates heat dissipation (cooling)
- destruction leads to hyperthermia
- A/C= anterior cooling
Function of Posterior Hypothalamic Nuclei
- mediates heat conservation
- destruction leads to hypothermia
- if posterior nucleus is destructed, you become poikilothemic (like a reptile)
Function of Arcuate Hypothalamic Nucleus
-secretion of DA (inhibits prolactin), GHRH, and GnRH
Function of Paraventricular Hypothalamic Nucleus
-antiduretic hormone, CRH, oxytocin, and TRH secretion
Function of Supraoptic Hypothalamic Nucleus
-secretion of antidiuretic hormone
Function of Suprachiasmatic Hypothalamic Nucleus
- circadian rhythym regulation and pineal gland fxn
- you need sleep to be charismatic
Where are the neurons that release serotonin in the brain?
-Raphe nuclei located in midbrain, pons, and medulla
Meningioma
- slow growing, benign tumor of meningothelial cells of arachnoid
- whorled pattern, psammoma bodies
- may cause seizures, HA, N
Valproate MOA and Side Effects
- inc. Na channel inactivation, inc. GABA concentration
- inhibits folate absorption-> neural tube defects in pregnancy
- GI distress, hepatotoxicity, weight gain
Locus Ceruleus
- plays role in panic attacks and panic disorder
- located in caudal pontine central gray matter
- contains large amounts of norepinephrine
Proptosis
-protrusion of eye ball
Cataplexy
- sudden loss of muscle tone that occurs in response to intense (usually positive) emotions
- associated with narcolepsy
Narcolepsy
- frequent overwhelming urges to sleep
- associated with cataplexy
- results from depletion of hypocretin-secreting neurons in the lateral hypothalamus
- short REM cycle
- hypnagogic (falling asleep) and hypnopompic (waking up) hallucinations
- low cerebrospinal fluid levels of hypocretin 1
Effect of epinephrine on a2 and b2 receptors in terms of insulin secretion.
- b2 (Gs) receptor binding by epi causes inc. insulin secretion
- a2 (Gi) receptor binding by epi causes dec. insulin secretion
- a2 effect usually is predominant leading to overall inhibition of insulin secretion
Medulloblastoma
- gait instability
- limb ataxia
- above are sx of cerebellar involvement
- sheets of primitive cells w/ many mitotic figures
- aggressive
- more common in kids
- commonly in cerebellar vermis
Ependymomas
- third most common brain neoplasm found in children
- in walls of ventricles and hamper CSF flow -> hydrocephalus
- rosettes
Brain Tumors in Kids
- Poilocytic astrocytoma-cystic
- medulloblastoma-sheets of cells with mitotic figures
- ependymoma-4th ventricle-> hydrocephalus, pseudorosettes
- craniopharyngioma- optic chiasm compression
What cells are involved in glial scar formation?
- astrocytes
- present several months to years after ischemia infarction
Effect of too rapid correction of chronic hyponatremia?
- osmotic demyelination of axons in the central pons
- called central pontine myelinolysis
- sx: spastic quadriplegia and pseudobulbar palsy
Decerebrate vs Decorticate Posturing
- brain damage at or below red nucleus (midbrain tegmentum, pons) causes decrerebrate (extensor) posturing
- damage to neural structures above red nucleus (cerebral hemispheres) results in decorticate (flexor) posturing
Glioblastoma
- most common primary cerebral neoplasm in adults
- poor prognosis
- arises from astrocytes
- may cross midline (butterfly glioma)
- contain areas of necrosis and hemorrhage
- solitary lesion differentiates from metastisis
Moro Reflex
- appropriate in babies up to 4 or 5 months
- beyond this age indicates neurological defects
What part of the basal ganglia when damaged will cause large amplitude limb movements?
-subthalamic nucleus
Uncle Herniation
- may result in compression of ipsilateral third cranial nerve
- causes fixed dilated pupil due to damage to parasymp fibers on outer portion of CN3
- may also see decerebrate posturing
