Neurology Flashcards
crossed hemisyndrome
when one side of the face has a neurological deficit, and the opposite side of the body also has (the same?) deficits;
= due to a brainstem lesion!
Hemiparesis
loss of motor control due to a cortical or subcortical hemispheric lesion
myopathy
muscle weakness with preserved sensation & reflexes
pseudoathetosis
(athetosis = unintentional writhing of hand;) pseudoathetosis = subconscious hand writhing due to loss of proprioception.
Stroke
sudden, focal brain dysfunction;
Caused by cerebral ischemic or hemorrhagic events.
Lewy Body
abnormal protein accumulation common in Parkinson’s Disease.
- circular, dark intracellularl;
- contains alpha-synuclein, ubiquitin, and other proteins
Cardinal signs of parkinsonism
“TRAP”
- Tremor
- Rigidity
- Akinesia/bradykinesia
- Postural changes
Causes of parkinsonism
1. Parkinson’s Diseases (idiopathic or genetic)
- Atypicals: Multiple System Atrophy (MSA), Lewy Body Disease, Progressive Supranuclear Palsy (PSP), corticobasal degeneration.
- drugs, toxins (antipsychotics, MPTP, CO)
path signs of frontotemporal dementia
Tau-like deposits & Pick bodies in fronto-temporal lobes;
Macro: cerebral atrophy
path signs of Lewy Body Dementia
location: fronto-temporal lobe
Macro: cerebral atrophy
Micro: Lewy Bodies
path signs of Huntington’s disease
Location: basal ganglia
Macro: neostriatal atrophy
Micro: neuron loss & astrocytosis
** chorea! **
path signs of ALS (Amylotrophic Lateral Sclerosis)
Location: motor cortex, brainstem and spinal cord (anterior horn)
Macro: motor neuron and muscle atrophy
Micro: inclusion bodies (look similar to Lewy bodies, but in spinal cord)
Path signs of Parkinson’s disease
Location: midbrain (substancia nigra & locus ceruleus)
Macro: loss of pigmentation in substancia nigra (was blue - dopamine)
Micro: Lewy Bodies w/ a-synuclein
** akinesia/bradykinesia + resting tremor **
Path signs of Alzheimer’s Disease
Location: temporo-parietal; ApoE or Presenilin mutations.
Macro: cerebral atrophy
Micro: neurofibrillary tangles (tau), b-amyloid plaques
** memory loss, decreased self-care/f(x) **
Prion disease
Location: diffusely through cortex
Macro: cerebral atrophy
Micro: prion protein deposits, neuron loss & reactive gliosis
Sx: progressive dementia + myoclonus
steps in assessment after 1st grand mal seizure
- take history (ask about drug use!)
- EEG: look for spikes (focal or generalized)
- imaging - CT or MRI: to ID structural abnormalities or other pathology (tumors, hemorrhage, etc)
Subarachnoid hemorrhage
“Worst headache of life,” often from rupture of cerebral hemorrhage
- can cause stroke
- risk secondary infarction due to P.Com. artery spasm up to 1 wk after initial hemorrhage.
Top causes of intracranial hemorrhage (–> stroke)
1 HTN -> microvascular rupture (esp. brainstem?)
- Amyloid angiopathy (esp. cortex, >80 yrs old)
- Vascular malformation
- Bleeding metastatic lesion
4 steps in pain processing
- Transduction: convert stimulus to action potential
- Transmission: send AP to brain
- Modulation: esp. by 5-HT & NE at dorsal horn (inhibitory), *targeted by pain meds!
- Perception: subjective, influenced by cultural factors and biological sensitization
Pain pathway (from mechanical stimulus to neural processing)
NocioR –> peripheral n. -> DRG (dorsal root ganglion) -> spinal cord -> thalamus -> brain (somatosensory cortex, frontal cortex & limbic system)
Clinical signs of Late Parkinson’s disease
decreased facial expression, decreased arm swing w/ walk, shuffling walk, decreased vocal volume
Progressive Supranuclear Palsy (“PSP”) clinical signs
(atypical parkinsonism)
- limited upward & downward gaze
- -> furrowed brow and startled expression;
- axial rigidity –> early falls (esp. backwards)
- hummingbird sign on MRI
Multiple System Atrophy (“MSA”) clinical signs
(atypical parkinsonism)
- early ANS & cerebellar dysfunction –> ataxia
- does NOT respond well to levodopa
- cerebellar & basal ganglia atrophy on MRI
Corticobasal Syndrome/Degeneration (“CBS/CBD”) clinical signs
(atypical parkinsonism)
alien limb and symmetric apraxia
Wilson’s Disease clinical signs
(atypical parkinsonism)
- movement disorders/ataxia
- psych disorders
- liver disease!
- low copper levels in blood & Kayser-Fleischer ring in iris
Lewy Body Disease (“LBD”) clinical signs
(atypical parkinsonism)
- cognitive fluctuations
- hallucinations
- falls
- w/ diffuse a-synuclein mutations
Acute subdural hematoma
cortical laceration and vascular injury (of cortical aa or bridging vv), progressively decreasing consciousness and increasing neuro Sxs.
-> concave hypERdensity on CT (on brain surface)
Tx: intubate, hyperventilate, mannitol, & craniotomy
50% mortality!
Chronic subdural hematoma
mild headache w/ progressive personality changes/dementia;
*in elderly, may not have specific Hx of trauma (esp. if + anticoag.)
–> concave hypOdensity on brain surface w/ CT, no skull fracture
Tx: Burr hole evacuation +/- catheter, anticonvulsants if Hx of seizure
*usually resolve well.
intracerebral hematoma
focal neuro Sxs w/ Hx of severe (penetrating) trauma, maintain consciousness.
–> hypERdensity IN brain parenchyma on CT
Tx: NO surgery unless very severe.
Acute epidural hematoma
Headache, nausea, & decreasing consciousness – usually after a “lucid period” (2-48 hrs), esp. in younger ppl.
usually laceration of Middle Meningeal a. w/ skull fracture (but no parenchymal trauma)
–> Lentiform hypERdensity on CT
Tx: intubate, hyperventilate, mannitol, & craniotomy
Appropriate treatment for peripheral nerve injury
a) sharp laceration: surgical repair ASAP
b) gunshot wound: surgical exploration & mark, but wait to repair
c) non-penetrating: monitor for 3 months (surgery only if need later)
Causes of insomnia
(canNOT sleep)
- Psychophysiological: acquired hypervigilant state
- Restless Leg Syndrome
- Circadian Rhythm Delay: inadequate timing or volume of sleep (esp. shift workers)
4 main symptoms of restless leg syndrome
- Leg discomfort (“creepy crawly” sensation)
- compulsion to move
- movement relieves discomfort
- worse at night and interferes w/ sleep
major features of Narcolepsy
excessive daytime sleepiness and CATAPLEXY (bulbar weakness elicited by strong emotions)
+/- auditory hallucinations just before sleep or just after wake up.
Pathophysiology of Narcolepsy
= autoimmune destruction of orexin neurons,
so less orexin in Reticular Activating System (lateral hypothalamus).
Multiple Sclerosis pathophysiology
Autoimmune process:
Autoreactive T cells attack CNS –> B cells take residence in CNS –> make oligoclonal IgG specifically in the CNS (distinct from serum IgG)
=> perivascular inflammation and demyelination -> axon loss acutely, glial scar/plaque chronically.
Multiple Sclerosis clinical picture
Sx: acute attacks of neuro Sxs, w/ progressive permanent deficits
ie: monocular vision loss, focal numbness & motor deficits, brainstem problems (diplopia, vertigo, hearing loss, facial weakness), impaired gait & impaired bowel/bladder function.
Dx: T2 MRI & CSF (w/ CNS IgG oligoclonal bands)
Tx: corticosteroids acutely, disease-modifiers to prevent relapse
**most often F, ~age 30.
Types of Multiple Sclerosis
- Relapsing-Remitting (RRMS): return to 100% normal in remission
- Secondary Progressive (SPMS): some residual deficits, progression from RRMS
- Primary Progressive (PPMS): worsens, no remission, M=F!
- Progressive Relapsing (PRMS): rare.
1st line Disease modifying treatments for Multiple Sclerosis
1. interferon B (IFN-B): IV, antiviral & immune-modulatory
*SE: hepatotoxic, spasticity, depression or Glatiramer acetate: block Ag presentation, shift T cells *SE: lipotropy
2nd line disease modifying therapy for Multiple Sclerosis
(immunosuppressants, risk other illness)
- Natalizumab: monoclonal Ab to a4-integrin (lymphocyte adhesion)
*SE: PML, hepatoxic
- Mitoxantrone: disrupts DNA synth/repair. for SP or RRMS
*SE: heart failure (cardiotoxic), leukemia
- Fingolimod: oral, block lymphocyte migration
(also Teriflunomide and Dimethyl fumarate)
Neuromyelitis Optica (NMO)
inflammatory CNS attack by anti-AQP4 autoAb, F>M
–> optic neuritis & transverse myelitis (of spinal cord)
Dx: Long spinal cord lesion (>3 vertebrae), NMOIgG, MRI to rule out MS
Tx: Methylprednisone, plasma exchange; or immunosuppression.
1st line MS drugs NOT effective
Acute Disseminated Encephalomyelitis (ADEM)
*mostly in children, = post-infectious/post-vaccine (rare now).
Sx: prodrome w/ fever, nausea, headache; onset w/ rapidly progressing stiff neck, multi-focal neuro Sxs, altered mental status!
Dx: WBC > 50, no oligoclonal bands
Tx: steroids (tapered) to prevent relapse. Usually full recovery
Path signs of MSA (Multiple System Atrophy)
oligodendroglial inclusion bodies reactive to a-synuclein & ubiquitin,
ANS symptoms & does not respond to L-DOPA
Path signs of PSP (Progressive Supranuclear Palsy)
tau-reactive glial & neuronal tangles w/ silver stain,
in subcortical sites (substancia nigra, GP, midbrain)
loss of voluntary vertical gaze
path signs of Cortico-Basal Degeneration (CBD)
Gross: cortical atrophy
Micro: Tau inclusions + ballooned neurons
in cerebral cortex (near sulcus), caudate, putamen, & substancia nigra
aphasia = major Sx
Friedrich’s Ataxia
Aut Recessive (frataxin mut.), young onset;
Sx: gait ataxia hyporeflexia, + cardiomyopathy/myocarditis
Path: deep cerebellum & spinal cord degeneration
* w/ spared cerebellar cortex
Spinal muscular atrophies
loss of lower motor neurons only.
* NO proximal neuronal tract degeneration
= Aut Dominant, SMN-1 mut.
- infantile (Werdnig-hoffman), intermed., late (Kennedy’s disease)
Spina bifida occulta vs. cystica
Occulta: asymptomatic bc no spinal cord herniation; spinal process absence.
Cystica: herniated spinal tissue = meningocele (just meninges) or myelomeningocele (spinal cord)
Arnold-Chiari Malformation
- Myelomeningocele (spina bifida cystica) - neuro deficits
- Vermis herniation (from shallow posterior fossa)
- Aqueduct stenosis –> hydrocephalus
- downward displaced pons
dysraphism
= failure of neural tube closure.
ie: spina bifida, encephalocele, anencephaly, holoprosencephaly
Neuro-Glial migration abnormalities
- associated w/ seizures bc thicker cortex/abnormal tissue structure
- Lissencephaly (smooth brain)
- Polymicrogyria (small gyri @ temporo-parietal)
- neuronal heterotopia (neurons in white matter bc incomplete migration)
Neurofibromatosis type 1 vs. type 2
NF-1: chrom. 17 mut, periph. -> skin lesions (vonRecklinghausen)
NF-2: chrom. 22 mut, Central –> bilat. acoustic schwannoma!, meningiomas/gliomas, lens opacity, cerebral calcification
1 insult to pre-term infant brain
Subependymal/Intraventricular Hemorrhage.
= hemorrhage bc can’t autoregulate cerebral BP
(hyaline membrane disease & Resp. distress –> rapid BP changes –> blood flow surges in brain => hemorrhage & herniation)
ischemic injury in infants
mostly white matter lesions esp. if premature.
1. Periventricular leukomalacia - premature
2. Multicystic encephalomalacia - full term, honeycomb cavities
…etc.
most common perinatal CNS infections
- CMV infection (hydrocephalus, CMV inclusion bodies)
- toxoplasmosis -> necrotizing meningoencephalitis if severe!
(hydrocephalus, ocular inflamm, megaencephaly) - HIV
path for Acute Disseminated Encephalomyelitis (ADEM)
#1: Perivenular lymphocyte infiltration of CNS, & demyelination by macrophages - extensive inflamm. infiltrates throughout brain parenchyma
Multiple Sclerosis pathology
inflammatory CNS demyelination, w/ acutely intact axons (some degradation w/ chronic bc ion channels moved)
Gross: discolored plaques @ optic n & near ventricles
Histo: astrocytosis & macrophage infiltration
