Neurology Flashcards
Astrocyte
Physical support Repair K+ metabolism Removal of excess neurotransmitters Component of blood brain barrier
Microglia
CNS phagocyte, derived from monocytes
Irregular nuclei, little cytoplasm, no discernible w/ Nissel stain
HIV infected microglia fuse to form multinucleate giant cells in the CNS
Oligodendroglia
Mylinates the axons of neurons in the CNS
Each oligodendroycte can myelinate many axons
Predominant type of glial cell in white matter
“Fried egg” appearance on H&E
Destroyed in MS and PML
Schwann cells
Each Schwann cell myelinated only 1 PNS axon
Also promotes axonal regeneration
Destroyed in GBS
Free nerve endings
C (slow), Adelta (fast)
Located in skin, epidermis, and some vicera
Pain and temperature
Meissner corpuscles
Large myelinated fibers, adapt quickly
Hairless skin
Dynamic, fine/light touch, position sense
Pacinian corpuscles
Large myelinated fibers, adapt quickly
Deep skin layers, joints
Vibration, pressure
Merkel discs
Large myelinated fibers, adapt slowly
Basal epidermal layer, hair follicles
Pressure, deep static touch, position sense
Right parietal temporal cortex lesion
Spatial neglect syndrome
Agnosia of the contralateral side of the world
Left parietal temporal cortex lesion
Gerstmann syndrome
Agraphia, acalculia, finger agnosia
Reticular activating system (midbrain) lesion
Reduced levels of arousal and wakefulness
Mammillary bodies lesions
Associated w/ thiamine deficiency
Wernicke-Korsakoff syndrome
Cerebellar hemisphere lesions
Intention tremor, limb ataxia, loss of balance
Fall toward side of lesions
Laterally located affecting lateral limbs
Cerebellar vermis lesions
Truncal ataxia, dysarthria
Centrally located, affects central body
Central pontine myelinolysis
Variant of osmotic demyelination syndrome
Acute paralysis, dysarthria, dysphagia, diplopia, and loss of consciousness
CAN cause locked in syndrome
Massive axonal demyelinaiton in pontine whir matter tracts 2ndary to osmotic forces and edema
Commonly iatrongenic, caused by overly rapid correction of hyponatremia
Broca aphasia
Broca Broken Boca (mouth)
Nonfluent aphasia with intact comprehension
Broca area: inferior front gyrus of front lobe
Wernicke aphasia
Wordy but makes no sense
Fluent aphasia with impaired comprehension and repetition
Wernicke area: superior temporal gyrus of temporal lobe
Global aphasia
Nonfluent aphasia with impaired comprehension
Both Broca and Wernicke areas affected
Conduction aphasia
Poor repetition but fluent speech, intact comprehension
Can be caused by damage to left superior temporal lobe and/or left supramarginal gyrus
Transcortical motor aphasia
Nonfluent aphasia w/ good comprehension and repetition
Motor: can’t really speak well but can feel (understand)
Transcortical sensory aphasia
Fluent speech but poor comprehension, good repetition
Sensory: can speak but cannot feel (understand)
Wallenberg syndrome
Lateral medullary syndrome Decreased pain and temperature sensation from ipsilateral face and contralateral body Dysphagia, hoarsness Decreased gag reflex Ipsilateral Horner syndrome
Brown-Sequard syndrome
Hemisection of spinal cord
Ipsilateral UMN signs below level of the lesion
Ipsilateral loss of tactile/vibration/proprioception at and below level of lesion
Contralateral pain and temperature loss below level of lesion
Ipsilateral loss of pain and temperature AT level of lesion
Ipsilateral LMN signs AT level of lesion
Horner syndrome
Sympathectomy of face
Ptosis (slight drooping of eyelid)
Anhidrosis (absence of sweating) and flushing
Miosis (pupil constriction)
Associated w/ lesion of spinal cord about T1 (Pancoast tumor, Brown-Sequard syndrome, late stage syringomyelia)
Landmark dermatones
T4 at the teat pore
T10 at the belly butten
L1 is the IL (inguinal ligament)
Glaucoma
Optic disc atrophy atrophy w/ characteristic cupping, usually with increased intraocular pressure and progressive peripheral visual field loss
Open angle: blocked trabecular meshwork from WBC, RBC, or retinal elements
Closed angle: enlargement or forward movement of lens against central iris leading to obstruction of normal aqueous flow leading to impeding flow of trabecular meshwork
Meyer loop (optic)
Sending info from inferior retina (sees up)
Loops around inferior horn of lateral ventricle (temporal lobe)
Dorsal (down) optic radiation
Sending info from superior retina (sees down)
Takes shorted path via internal capsule (parietal lobe)
Internuclear opthalmoplegia (INO)
Lesions seen in patients w/ demyeliation in the medial longitudinal fascicles (MLF)
Lack of communication such that when CN VI muscle activates ipsilateral lateral rectus, contralateral CN III nucleus does not stimulate medial rectus to fire and abducting eye gets nystagmus
Acute inflammatory demyelinating polyradiculopathy
Autoimmune condition that destroys Schwann cells (GBS)
Inflammation and demylinaiton of peripheral nerves and motor fibers
Results in symmetric ascending muscle weakness/paralysis beginning in lower extremities
Progressive multifocal leukoencephalopathy
Demylination of CNS due to destruction of oligoendrocytes
Associated w/ JC virus
Increased risk w/ use of natalizumab (anti-integrin)
Acute disseminated (post infectious) encephalomyelitis
Multifocal perivenular inflammation and demylination after infection (commonly measles or VZV) or certain vaccinations (rabies, smallpox)
Charcot-Marie-Tooth disease
Hereditary motor and sensory neuropathy
Defective production of proteins involved in the structure and function of peripheral nerves or the myelin sheath
Sturge-Weber syndrome
Congenital non inherited developmental anomaly of neural derivatives
Affects small capillary sized blood vessels –> port wine stain of the face
Ipsilateral leptomenginal angioma –> seizure/epilepsy
Brimondine
Alpha2 agonist decreasing aqueous humor synthesis
Treat glaucoma
Can cause blurry vision
Timolol
Beta blocker decreasing aqueous humor synthesis
Treat glaucoma
No vision changes
Azetazolamide
Diuretic decreasing aqueous humor synthesis via inhibition of carbonic anhydrase
Also act on proximal tubule of kidney, leading to increased secretion of bicarb and increased tubular pH
No vision change
Tramadol
Very weak opioid agonist
Also inhibit serotonin and norepi reuptake
Treat chronic pain
Can cause serotonin syndrome and decrease seizure threshold
Ethosuximide
Block thalamic T-type Ca2+ channels
Treat absence seizure
Carbamazepine
Increase Na+ channel inactivation
Treat simple, complex, tonic-clonic seizure
1st line for trigeminal neuralgia
Can cause blood dyscrasias (agranulocytosis, aplastic anemia)
Valporic acid
Increase Na+ channel inactivation
Increase GABA by inhibiting GABA transaminase
Treat tonic-clonic seizure, bipolar disorder
Hepatotoxicity
Dantrolene
Prevent release of Ca2+ from sarcoplasmic reticulum of skeletal muscle
Use to treat malignant hyperthermia and neuroleptic malignant syndrome
Bromocriptine
Dopamine agonist
Treat Parkinson’s
L-dopa(levodopa)/carbidopa
Increase level of dopamine in brain
L-dopa can cross blood brain barrier
Carbidopa, a peripheral decarboxylase inhibitor, increase the bioavailability of L-dopa in the brain
Treat Parkinson’s
Can cause arrhythmias, long term use can lead to dyskinesia
Selegiline
Selective MAO type B inhibitor, prevents dopamin breakdown
Treat Parkinson’s
Donepezil
AChE inhibitor
Treat Alzheimer
Bentropine
Antimuscarinic
Improves tremor and rigidity for Parkinson’s
Memantine
NMDA receptor antagonist, help prevent excitotoxicity (mediated by Ca2+)
Treat Alzheimer
