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Neuropathology, ophthalmology, common brain lesion, movement diorder,…
Neuropathology
ophthalmology
visual field defects
right Meyer loop(temporal lobe)→left upper quadrantanopia
right dorsal optic radiation(parietal lobe)→left lower quadrantanopia
right optic tract→left homonymous hemianopia(同名半盲)
PCA infarct→hemianopia with macular sparing
optic chiasm→bitemporal hemianopia(両耳側性半盲)
macula→central scotoma
right optic nerve→right anopia
terms
Meyer loop: loops around inferior horn of 4th ventricles
dorasal optic radiation: takes shortest path via internal capsules
refractive errors
myopia(近視)
nearsightness, light focused in front of retina, correct with concave lenses(凹レンズ)
astigmatism(乱視)
abnormal curvature of cornea→different refractive power at different axis, correct with cylindrical lens
hyperopia(遠視)
farsightedness, light focused behind retina, corect with convex lenses(凸レンズ)
presbyopia(老眼)
aging related impaired accommodation (focusing on near object)
due to ↓lens elasticity, changes in lens curvature, ↓strength of the ciliary muscle
reading glass
correctable with glasses
glaucoma
open-angle glaucoma
primary-cause unclear; secondary-blocked trabecular meshwork from WBCs, EBCs, retinal element
age, African-American, family history, painless
closed-angle graucoma
chronic closure: often asymptomatic
acute closure: emergency, halos(光輪) around lights, frontal headache, fixed and mid-dilated pupil; mydriastic agent contraindicated
secondary-hypoxia from retinal disease induces vasoproliferation in iris that contracts angle
primary-enlargement or anterior movement of lens→obstruction of normal aqueous flow through pupil→fluid build up behind iris, pushing peripheral iris against cornea and impeding flow through trabecular meshwork
optic disc atrophy with characteristic cupping (thinning of outer rim of optic nerve head), usually with elevated IOP and progressive visual field loss
treatment: ↓IOP (pharmacologic or surgical)
uveitis
anterior→iritis; posterior→choroiditis and/or retinitis
associated with systemic inflammatory disorders
inflammation of uvea, hypopyon or conjunctival redness
age-related macular degeneration(加齢黄斑変性)
wet(exudate)
rapid loss of vision due to bleeding 2° to choroidal neovascularization
treatment: anti-VEGF injection
dry(nonexudate)
deposition of yellowish extracellular material in between Bruch membrane and retinal pigment epithelium with ↓ vison
treatment: prevent progression with multivitamin and antioxidant supplements
degeneration of macula, cause distortion and eventual loss of central vision
hypertensive retinopathy
flame-shaped retinal hemorrhage, arteriovenous nicking(網膜動静脈血管狭窄), microaneurysms, macular star, cotton-wool spot
↑ risk of stroke, CAD, kidney disease
retinal damage due to chronic HTN
CNⅢ, Ⅳ, Ⅵ palsies
CNⅣ damage
eye move upward, particularly with contralateral gaze
CNⅥ damage
affected eye unable to abduct and is displaced medially in primary position of gaze
CNⅢ damage
common causes: ischemia, uncal herniation, PCA aneurysm, cavernous sinus thrombosis, midbrain stroke
motor output: ptosis, down and out gaze
has motor and parasympathetic compoents
parasympathetic output: diminished or absent pupillary light reflex, brown pupil
cavernous sinus(海綿静脈洞)
components
occulomotor.n, trochlear.n, ophthalmic.n, maxillary.n, abducens.n
cavernous portion of internal carotid artery
cavernous sinus syndrome
due to pituitary tumor, carotid cavernous fistula, cavernous sinus thrombosis
ophthalmoplegia(眼瞼麻痺), ↓corneal sensation, Horner syndrome, decreased maxillary sensation
collection of venous sinuses on either side of pituitary, blood from eye and superficial cortex→cavernous sinus→internal jugular vein
conjunctivitis
causes
allergic: itchy, bilateral
bacterial: pus
viral: most common, often adenovirus, sparse mucous discharge, swollen preauricular node, self resolving
inflammation of conjunctica, red eye
cataract
risk factors: age, smoking, alcohol, sunlight, corticosteroid, diabetes, trauma, infection; galactosemia, galactokinase deficiency, trisomies, ToRCHeS infection, Marfan syndrome, Alport syndrome, myotonic dystrophy, NF2
painless, often bilateral, opacification(混濁) of lens→glare(まぶしさ), ↓vision
diabetic retinopathy
two types
nonproliferative
damaged capillaries leak blood→hemorrhage and macular edema; treat with blood sugar control
proliferative
chronic hypoxia→new blood vessel formation; treat with peripheral retina photocoagulation, surgery, anti-VEGF
retinal damage due to chronic hyperglycemia
retinal vein occlusion
retinal hemorrhage and engorgement(充血) (blood and thunder appearance) , edema
blockage of retinal vein due to compression from nearby arterial atherosclerosis
retinal detachment
crickling of retinal tissue and changes in vessel direction
separation of neurosensory layer of retina→degeneration of photoreceptors→vision loss (due to retinal break, diabetic traction, inflammatory effusion
retinitis pigmentosa
inherited retinal degeneration, painless, progressive vision loss begining with night blindness
bone spicule-shaped deposits around macula
Horner syndrome
lesions along sympathetic chain
1st: pontine hemorrhage, lateral medullary syndrome, spinal cord lesion above T1
2nd: Pancoast syndrome(stellate ganglion)
3rd: carotid dissection
sympathetic denervation of face→ptosis(superior tarsal muscle;上瞼板筋), anhidrosis and flushing of affected side of face, miosis
internuclear ophthalmoplegia(核間性眼筋麻痺)
lesion of MLF→when CN6 nucleus activate ipsilateral LR, contralateral CN3 nucleus does not stimulate MR to contrast→abducting eye gets nystagmus
MLF: pair of tracts that allows for crosstalk between CN6 and CN3 nuclei, coordinate both eyes to move in same horizontal direction
central retinal artery occlusion
acute, painless monocular vision loss, retina cloudy with attenuated(減衰した) vessels and cherry red spot at fovea
retinitis
retinal edema and necrosis leading to scar, often viral, but can be bacterial or parasitic
papilledema(乳頭浮腫)
optic disk swelling due to ↑ICP, enlarged blind spot and elevated optic disk with blurred margins
Marcus Gunn pupil
when the light is then swung to affected eye, both pupils dilate (normally constrict) due to impaired conduction of light signal (injured optic nerve)
common brain lesion
red nucleus
decorticate(flexor) posturing: above red nucleus, flexion of upper extrimities and extension of lower extrimities
decerebrate(extensor) posturing: at or below red nucleus, extension of upper and lower extrimities
dominant parietal cortex
agraphia(失書症), acalculia(失計算), finger agnosia, left-right disorientation
subthalamic nucleus
contralateral hemiballismus
hippocampus
anterograde anemia
frontal lobe
disinhibition and deficit in concentration, orientation, judgement; may have reemergence of primitive reflex
paramedian pontine reticular formation
eyes look away from side of lesion
medial longitudinal fasciculus
internuclear ophthalmoplegia(核間性眼筋麻痺): impaired adduction of ipsilateral eye; nystagmus(眼振) of contralateral eye with abduction
nondominant parietal cortex
agnosia(失認) of contralateral side of the world; hemispatial neglect syndrome(半側空間無視)
frontal eye fields
eye look toward side of lesion; in seizure, eye look away from side of lesion
basal ganglia
tremor, chorea, athetosis; Parkinson, Huntington
cerebellar hemisphere
intention tremor, limb ataxia, loss of balance (ipsilateral)
mammillary bodies
Wernicke-Korsakoff syndrome: confusion, ataxia, nystagmus, ophthalmoplegia(眼筋麻痺), memory loss, confabulation(作話), personality change
dorsal midbrain
Parinaud syndrome: vertical gaze palsy, pupillary light-near dissociation, lid retraction, convergence-retraction nystagmus(輻輳眼振)
reticular activating system
reduced level of arousal and wakefulness
amygdala(扁桃体)
Kluver-Bucy syndrome: disinhibited behavior
cerebellar vermis(小脳虫部)
truncal ataxia, dysarthia(構音障害)
movement diorder
chorea
sudden, jerky, purposeless movement (basal ganglia)
Huntington disease, acute rheumatic fever
essential tremor
high frequency tremor with sustained posture, worsened with movement or when anxious
often familial
akathisia
restlessness and intense urge to move
neuroleptic use or Parkinson disease
asterixis
hepatic encephalopathy, Wilson disease, etc
extension of wrists causes flapping motion
restless legs syndrome
worse at rest/nighttime, relieved by movement
associated with iron deficiency, CKD
resting tremor
uncontrolled movement of distal appendages, alleviated by intentional movement (substantia nigria;黒質)
Parkinson disease
hemiballismus
sudden, wild flailing of 1 arm, +/- ipsilateral leg
contralateral subthalamic nucleus
intention tremor
slow, zigzag motion when pointing/extending toward target
cerebellar dysfunction
dystonia
sustained, involuntary muscle contraction
athetosis
slow, snake-like, writhing(もがく) movement especially in finger (basal ganglia)
myoclonus
sudden, brief, uncontrolled muscle contraction
neurodegenerative disorders
Parkinson disease
Lewy body: intracellular eosinophilic inclusion
loss of dopaminergic neurons of substantia nigria pars compacta(黒質緻密部)
tremor, rigidity, akinesia(無動症), postural instability, shuffling gait(引きずり歩行)
Huntington disease
chorea, athetosis, aggression, depression, dementia
caudate(尾状核) lose ACh and GABA
AD trinucleotide repeat expansion in the huntingtin gene on chromosomal4, age 20 to 50
atrophy of caudate and putamen
↑dopamine, ↓GABA, ↓ACh
Alzheimer disease
earlier onset
widespread cortical atrophy, especially hippocampus, narrowing of gyri and widening of sulci
associated with altered proteins: ApoE-2, ApoE-4, APP, presenilin-1,2
senile plaque(老人斑) (extracellular β-amyloid core); neurofibrillary tangles(神経原線維濃縮体) (intracellular, hyperphosphorylated tau protein
most common cause of dementia in elderly, Down syndrome patients have ↑risk, ↓ACh
frontotemporal dementia; Pick disease
inclusion of hyperphosphorylated tau protein (round Pick body) or ubiquitinated TDP-43
frontotemporal lobe degeneration
change in personality and behavior, or aphasia
Lewy body dementia
intracellular Lewy bodies in cortex
visual hallucination, dementia, REM sleep behavior disorder, parkisonism
vascular dementia
2nd most common cause of dementia
in cognitive ability with late-onset impairment
result of multiple arterial infarct and/or chronic ischemia
Creutzfeldt-Jakob disease
spongiform cortex
rapidly progressive dementia with myoclonus and ataxia
demyelinating and dysmielinating disorders
multiple sclerosis
exacerbate with increased body temperature, relapsing and remitting(緩和する), women in 20s and 30s
↑IgG, ↑myelin basic protein in CSF, oligoclonal band, periventricular plaques, multiple white matter lesion disseminated
acute optic neuritis, brainstem/cerebellar syndrome, pyramidal tract weakness, spinal cord syndrome
treatment: IV steroids(acute flare); symptomatic treatment; disease-modifying therapy
autoimmune inflammation and demyelination of CNS with axonal damage
osmotic demyelination syndrome
acute paralysis, dysarthia, dysphagia, diplopia, loss of consciousness
after correction of hyponatremia
massive axonal demyelination in pontine white matter due to rapid osmotic damage
central pontine myelinolysis
acute inflammatory demyelinating polyradiculopathy(多発根神経炎)
most common subtype of Guillain-Barre syndrome
autoimmune condition associated with infection, inflammation and demyelination of peripheral nerve and motor fibers
due to molecular mimicry, inoculation(接種), stress
symmetric ascending muscle weakness/paralysis and depressed DTR(深部腱反射), other neural defect
majority recover completely after weeks to months
acute disseminated encephalomyelitis
multifocal inflammation and demyelination after infection or vaccination
Charcot-Marie-Tooth disease
AD, CMT1A, caused by PMP22 duplication
foot deformities, lower extrimity weakness
progressive hereditary nerve disorders related to defective production of protein →defective peripheral nerves or myelin sheath
progressive multifocal leukoencephalopathy
JC virus infection, due to AIDS
rapid and progressive
demyelination of CNS due to destruction of oligodendrocyte
Krabbe disease, metachromatic leukodystrophy, adrenoleukodystrophy
spinal cord lesions
amyotrophic lateral sclerosis(筋委縮性側索硬化症)
LMN→dysarthria, dysphagia, asymmetric limb weakness, fasciculations, atrophy)
UMN→dysarthria, dysphagia, emotional lability, spatic gait, clonus
UMN and LMN(anterior horn) degeneration
treatment: riluzole
tabes dorsalis(脊髄ろう)
from degeneration of dorsal columns and roots→progressive sensory ataxia
+Romberg sign and absent DTRs
caused by 3° syphilis
cauda equina syndrome(馬尾症候群)
unilateral radicular pain, absent knee and ankle reflex, loss of anal and bladder sphincter control, saddle anesthesia
treatment: surgery and steroid
compression of spinal roots L2 and below, often due to intervertebral disc herniation or tumor
complete occlusion of anterior spinal artery
UMN deficit below the lesion; LMN deficit at level of the lesion; loss of pain and sansation below the lesion
mid-thoracic ASA teritory is watershed area, can be caused by aortic aneurysm repair
spinal muscular atrophy
SMA type 1 called Werdnig-Hoffmann disease
congenital degeneration of anterior horn, LMN only, symmetric, hypotonia, tongue fasciculation, AR(SMN1 gene)
vitamin B12 deficiency
demyelination of spinocerebellar tracts, lateral corticospinal tracts, dorsal columns
ataxic gait, paresthesia, impaired position/vibration sense
syringomyelia(脊髄空洞症)
seen with Chiari 1 malformation
syrinx(鳴管) expands and damage anterior white comissure of spinothalamic tract→bilateral symmetrical loss of pain and temperature sensation
stroke, hemorrhage, etc
ischemic brain disease/stroke
CT detects ischemic change in 6-24hr, diffusion-weight MRI within 3-30min
time event
12-24hr: eosinophilic cytoplasm, pyknotic nuclei(核濃縮)
24-72hr: necrosis, neutrophil
3-5days: macrophage
1-2weeks: reactive gliosis, vascular proliferation
.>2weeks: glial scar
place: hippocampus, neocortex, cerebellum, watershed areas
ischemic stroke
acute blockage of vessels→disruption of blood flow and subsequent ischemia→liquefactive necrosis
types
thrombotic
due to a clot forming directly at site of infarction, usually over an atherosclerotic plaque
embolic
embolus from another part
hypoxic
due to hypoperfusion or hypoxemia
treatment: tPA (within3-4.5 hr), optimum control
irreversible damage begins after 5 minutes of hypoxia
transient ischemic attacl
brief, reversible episode of focal neurologic dysfunction without acute infarction, with the majority resolving in 15 minutes, due to focal ischemia
neonatal intraventricular hemorrhage
premature and low-birth weight infants
altered level of consciousness, bulging fontanelle(大泉門隆起), hypotension, seizures, coma
bleeding into ventricles, in germinal matrix
intracranial hemorrhage
subdural hematoma(硬膜下血腫)
also seen in shaken child
crescent-shaped hemorrhage that cross suture lines, midline shift
rupture of bridging veins, acute(hyperdense) or chronic(hypodense)
subarachnoid hemorrhage(クモ膜下血腫)
worst headache of my life, bloody or yellow spinal tap, vasospasm 3-10 days after hemorrhage→ischemic infarct (use nimodipine to prevent vasospasm
bleeding due to trauma or rupture of aneurysm or arteriovenous malformation, rapid
epidurnal hematoma(硬膜外血腫)
scalp hematoma, rapid intracranial expansion under systemic arterial pressure→transtentorial herniation(テント切痕ヘルニア), CN3 palsy
biconvex(両凸), hyperdense blood collection not crossing suture lines(縫合線)
rupture of meddile meningeal artery, often due to skull fracture involving the pterion
intraparenchymal hemorrhage(脳内出血)
Charcot-Bounchard microaneurysm commonly occur in putamen(被殻) of basal ganglia
commonly caused by systemic hypertension, also seen with amyloid angiopathy, vasculitis, neoplasm
effect of stroke
anterior circulation
anterior cerebrel artery
contralateral paralysis and sensory loss
motor and censory cortices(lower limbs)
leticulostriate artery(レンズ核線条体動脈)
contralateral paralysis, abdence of cortical sign
location of lacunar infarct
striatum, internal capsule
middle cerebral artery
contralateral paralysis and sensory loss, aphegia (dominant hemisphere), hemineglect(nondominant)
motor and censory cortices(upper limb and face), tamporal lobe(Wernicke srea), fronatal lobe(Broca area)
posterior
anterior inferior cerebellar artery
facial nucleus→paralysis of face, ↓lacrimation, salivation, taste from anterior 2/3 of tongue
vestibular nuclei→vomiting, vertigo, nystagmus
lateral pons
spinothalamic tract, spinal trigeminal nucleus→↓pain and temperature sensation (contralateral body, ipsilateral face)
sympathetic fiber→ipsilateral Horner syndrome
middle and inferior penduncles→ataxia, dysmetria(測定障害)
labyrinthine artery(迷路動脈)→ipsilateral sensorineural deafness, vertigo
lateral pontine syndrome
basilar artery
corticospinal and corticobulbar tract→loss of voluntary facial, mouth and tongue movement
ocular nerve nuclei, paramedian pontine reticular formation→loss of horizontal eye movement
pons, medulla, lower midbrain→reticular activating system(RAS) spared, therefore preserved consciousness
posterior inferior cerebellar artery
lateral medulla;nucleus ambiguus→dysphagia, hoarseness, ↓gag reflex, hiccups; vestibular nuclei(前庭神経核)→vomiting, vertigo, nystagmus; lateral spinothalamic tract, spinal trigeminal tract→↓pain and temperature sensation(contralateral body, ipsilateral face); sympathetic fiber→ipsilateral Horner syndrome; inferior cerebellar peduncle→ipsilateral ataxia, dysmetria
lateral medullary syndrome
posterior cerebral artery
occipital lobe→contralateral hemianopia with macular sparing, alexia(失語) without agrephia(失書)
anterior spinal artery
medial leminiscus(内側毛帯)→↓contralateral proprioception
caudal medulla(hypoglossal nerve)→ipsilateral hypoglossal dysfunction
lateral corticospinal tract→contralateral paralysis(upper and lower limbs)
medial medullary syndrome: infarct of paramedian branches of ASA and/or vertebral artery
central post stroke pain syndrome
neuropathic pain due to thalamic lesions
diffuse axonal injury
devastating neurologic injury
caused by traumatic shearing forces during rapid acceleration/deceleration of the brain
aneurysms
saccular aneurysm(嚢状動脈瘤)
most common site is junction of ACom and ACA, associated with ADPKD, Ehles-Danlos syndrome, risk is age, hypertension, smoking
silent until rupture→subarachnoid hemorrhage→focal neurologic deficits
complications
ACom
compression→bitemporal hemianopia(両耳側性半盲), visual acuity deficit, rupture→ischemia in ACA distribution→contralateral lower extrimity hemiparesis, sensory deficits
MCA
rupture→ischemia in MCA distribution→contralateral upper extrimity and facial hemiparesis, sensory deficits
PCom
comperssion→ipsilateral CN3 palsy→mydriasis, ptosis(眼瞼下垂)
Charcot-Bouchard microaneurysm
associated with chronic hypertension, cancause lacunar stroke
abnormal dilation of an artery due to weakning of vessel wall
seizure
generalized seizures
myoclonic: quick, repetitive jerks(けいれん)
tonic-clonic: alternating stiffening and movement
absence: 3 Hz spike-and-wave discharges, no postictal(発作後), blank stare
tonic: stiffening
atonic: drop seizure, commonly mistaken for fainting
partial sizures
simple partial: consciousness intact, motor, sensory, sutonomic, psychic
complex partial: impaired consciousness, automatisms
single area of brain, commonly in medial temporal lobe
age
adult: tumor, trauma, stroke, infection
elderly: stroke, tumor, trauma, metabolic, infection
children: genetic, infection, trauma, congenital, metabolic
epilepsy
diorder of recurrent seizure
status epilepticus(てんかん発作重積状態)
continuous or recurring seizure that may result in brain injury
characterized by synchronized, high-frequency neuronal firing
headache
migraine headache(片頭痛)
pulsating pain with nausea, photophobia, phonophobia
due to irritation of CN5, meninges, blood vessels
unilateral, 4-72hr
trigeminal neuralgia(三叉神経痛)
by chewing, talking, touching
repetitive, unilateral, shooting pain
cluster(群発頭痛)
excruciating(耐え難い) periorbital pain with lacrimation and rhinorrhea(鼻漏)
unilateral, 15min-3hr, repetitive
tension(緊張性頭痛)
steady, band like pain
bilateral, >30min(constantly 4-6hr), constant
treatment: cluster→sumatriptan, O₂; others→NSAIDs,etc
idiopathic intracranial hypertension
risk factors: female, tetracycline, obesity, vitamin A excess, danazol
treatment: weight loss, acetazolamide
lumbar puncture(腰椎穿刺) reveals ↑opening pressure and provides temporary headache relief
pseudotumor cerebri
↑ ICP with no apparent cause on imaging
neurocutaneous disorder
neurofibromatosis type1
NF1 tumor suppressor gene, AD
cafe-au-leit spot, cutaneous neurofibromas, optic gliomas, pheochromocytomas, Lisch nodules
von Hippel-Lindau disease
development of numerous tumors
hemangioblastomas in retina, brain stem, cerebellum, spine, angiomatosis, bilateral renal cellcarcinoma, pheochromocytomas
deletion of VHL gene, AD
neurofibromatosis type2
mutation in NF2 tumor suppressor gene, AD
bilateral acoustic schwannomas, juvenile cataracts, meningiomas, ependymomas
Sturge-Weber syndrome
congenital, noninherited, developmental anomaly of neural crest due to somatic mosaicism (mutation in GNAQ gene)
port-wine stain of the face, ipsilateral leptomeningeal angioma(軟髄膜血管腫), seizure, epilepsy, intellectual disability, glaucoma
encephalotrigeminal angiomatosis
tuberous sclerosis
hamartomas(過誤腫), angiofibromas, mitral regurgitation, ash-leaf spot, cardiac rhabdomyoma, mental retardation, renal angiomyolipoma, seizure
TSC1 or TSC2 mutation (tumor suppressor gene), AD
hydrocephalus
communicating
communicating hydrocephalus
↓CSF absorption by arachnoid granulations→↑ICP, papilledema, herniation
normal pressure hydrocephalus
urinary incontinence, gait apraxia(歩行失行), cognitive dysfunction
elderly, idiopathic, not increased subarachnoid space volume, expansion of ventricles distorts the fiber of corona radiata(放射冠)
ex vacuo ventriculomegaly(真空脳室拡大)
due to ↓brain tissue and neuronal atrophy
noncommunicating
caused by structural blockage of CSF circulation within ventricular system
↑CSF volume→ventricular dilation
herniation
uncal herniation(鉤ヘルニア)
compress ipsilateral CN3 and contralateral crus cerebri(大脳脚)→contralateral CN3 palsy and ipsilateral hemiparesis
medial temporal lobe
cerebellar tonsillar herniation
coma, death
into foramen magnum
cingulate(subfalcine) herniation; 帯状回(大脳鎌下)ヘルニア
compress ACA
under falx cerebri(大脳鎌)
transtentorial(central/downward) herniation;テント切痕(中心性/下行性)ヘルニア
caudal displacement of brain stem→rupture of paramedian basilar artery branch→Duret hemorrhage
poliomyelitis(灰白髄炎)
asymmetric weakness, hypotonia, flaccid paralysis(弛緩性麻痺), fasciculation, hypoflexia, muscle atrophy
↑WBC, slight ↑ protein in CSF
destruction of cells in anterior horn of spinal cord(LMN death)
caused by poliovirus
Friedreich ataxia
degeneration of lateral corticospinal tract, spinocerebellar tract, dorsal column, dorsal root ganglia
AR trinucleotide repeat disorder(GAA on 9:encode frataxin)
impairment in mitochondrial functioning
staggering gait(よろめき歩行), frequent falling, nystagmus, dysarthria, pes cavus, hammer toes, diabetes mellitus, hypertrophic cardiomyopathy, kyphoscoliosis(脊柱後側弯症)
otology
diagnosis of hearing test
conductive
weber→localizes to affected ear; rinne→abnormal
sensorineural
weber→localizes to unaffected ear; rinne→normal
type
noise-induced hearing loss(騒音性難聴)
damage to sterociliated(不動毛) cells in organ of Corti
presbycusis(老年難聴)
aging related progressive bilateral sensorineural hearing loss due to destruction of hair cells at cochlear base
cholesteatoma(真珠腫)
overgrowth of desquamated keratin debris within middle ear space
may erode ossicles, mastoid air(乳突蜂巣) cells→conductive hearing loss
vertigo
peripheral vertigo
semicircular canal debris, vestibular nerve infection, Meniere disease, benign paroxysmal positional vertigo(良性発作性頭位めまい症)
treatment: antihistamine, anticholinergics, antiemetics
more common, inner ear etiology
central vertigo
neurologic findings
brain stem or cerebellar lesion
aphasis(失語症)
repetition impaired
Wernicke
fluent, impaired comprehension
make no sense, do not have insight
superior temporal gyrus of temporal lobe
conduction(伝導性)
caused by damage to arcuate fasciculus(弓状束)
fluent, intact comprehension
Broca
inferior frontal gyrus of frontal lobe
nonfluent, intact comprehension
global
nonfluent, impaired comprehension
all areas are affected
repetition intact
transcortical sensory
fluent, impaired comprehension
temporal lobe around Wetnicke area
transcortical, mixed
transcortical motor
nonfluent, intact comprehension
frontal lobe around Broca area
definition
aphasia: higher order language deficit, caused by pathology in dominant cerebral hemisphere
dysarthria: motor inability to speak
Brown-Sequard syndrome
contralateral loss of pain, temperature, crude touch below level of lesion
ipsilateral UMN signs, ipsilateral loss of proprioception , vibration, light touch, tactile sense(触覚) below level of lesion
ipsilateral loss of all sensation, ipsilateral LMN sign at level of lesion
brain tumors
adult
meningioma
often symptomatic, may present with seizures or focal neurologic signs
apindle cells concentrically arranged, psammoma bodies(砂粒小体)
common, typically benign, female, near surface of brain and parasagittal region(傍矢状域), arachnoid cell origin
hemangioblastoma
closely arranged, thin walled capillaries with minimal intervening paranchyma(実質)
most often cerebellar, associated with von Hippel Lindau syndrome, produce EPO, blood vessel origin
oligodendroglioma
fried egg cells that have round nuclei with clear cytoplasm
most often in frontal lobe, slow growing, oligodendrocyte origin
pituitary adenoma
mass effect: bitemporal hemianopia, hypopituitarism, headache
hyperplasia of only one type of endocrine cells
nonfunctioning or hyperfunctioning, most commonly prolactinoma; less comonly adenoma producing GH, ACTH; rarely, TSH, FSH, LH
plolactinoma→galactorrhea, amenorrhea, ↓ bone density, low libido, infertility
treatment: dopamin agonist, transsphenoidal(経蝶形骨洞) resection
glioblastoma multiforme(多形性膠芽腫)
GFAP+, pseudopalisading(偽柵状配列) plemorphic tumor cell border central areas of necrosis, hemorrhage, microvascular proliferation
grade 4 astrocytoma, common, malignant, found in cerebral hemisphere, astrocyte origin
schwannoma
bilateral vestibular schwannoma found in NF-2
dense, hypercellular areas containing spindle cells→hypocallular and myxoid areas
at cerebellopontine angle, CN7,8 and peripheral nerve, schwann cell origin, S-100+
childhood
ependymoma
found in 4th ventricle, cancause hydrocephalus, poor prognosis, ependymal cell origin
perivascular pseudorosettes, red-shaped basal ciliary bodies
craniopharyngioma
calcification, cholesterol crystal
supratentorial, from remnant of Rathke pouch
medulloblastoma
form of primitive neuroectodermal tumor, Homer-Wright rosettes, small blue cell
most common malignant, cerebellum, can compress 4th ventricles
pinealoma
Parinaud syndrome: compression of tectum(視蓋)→vertical gaze palsy; obstructive hydrocephalus; precocious puberty in male(早発思春期)
similar to germ cell tumor
tumor of pineal gland
pilocytic astrocytoma(毛様細胞性星細胞腫)
GFAP+,rosenthal fibers (eosinophilic, corkscrew fibers)
low-grade astrocytoma, most common, well circumscribed, in posterior fossa or supratentorial, benign, glial cell origin
cranial nerve lesion
facial nerve lesion
usually after HSV; other causes are Lyme disease, herpes zoster, sarcoidosis, tumor, diabetes mellitus
treatment: corticosteroid±acyclovir
Bell palsy is the most common cause of peripheral facial palsy
upper motor neuron lesion
contralateral, lower muscle, forehead not involved
motor cortex, connection from motor cortex to facial nucleus in pons
lower motor neuron lesion
ipsilateral, upper and lower muscle, forehead involved
incomplete eye closure, hyperacusis(聴覚過敏), loss of taste sensation to anterior tongue
facial nucleus, anywhere along CNⅦ
common lesions
Ⅹ
uvula(口蓋垂) deviate away from side of lesion
Ⅺ
weakness turning head to contralateral side of lesion(SCM), shoulder droop on side of lesion(trapezius)
Ⅴ
jaw deviate toward side of lesion due to unopposed force from the opposite pterygoid muscle(翼突筋)
Ⅻ
LMN lesion, tongue deviate toward side of lesion due to weakened tongue muscle on affected side