Neuro and Special Senses Flashcards
1
Q
Neuroepithelia in neural tube become what?
A
CNS neurons, ependymal cells, oligodendrocytes, astrocytes
2
Q
What do neural crest cells become in the brain?
A
PNS neurons and Schwann cells
3
Q
What does the mesoderm become in the brain?
A
Microglia
4
Q
Risks for neural tube defects?
A
Maternal diabetes as well as low folic acid intake
5
Q
Labs of NTD?
A
Elevated AFP and AChE as confirmatory
6
Q
What is holoprosencephaly and risk factors?
A
Failure of left and right hemispheres to separate
Seen in trisomy 13 and fetal alcohol syndrome
7
Q
Clinical presentation of holoprosencephaly?
A
Moderate form has cleft lip/palate, most severe form results in cyclopia
MRI: monoventricle and fusion of basal ganglia
8
Q
Chiari I malformation
A
Ectopia of cerebellar tonsils
Asymptomatic; HA in adulthood
Assoc w/ syringomyelia
9
Q
Chiari II malformation
A
Herniation of low-lying cerebellar vermis and tonsils through foramen magnum with aqueductal stenosis -> hydrocephalus
Assoc w/ LS meningomyelocele
10
Q
Dandy-Walker syndrome
A
Agenesis of cerebellar vermis with cystic enlargement of 4th ventricle
Assoc w/ noncommunicating hydrocephalus, spina bifida
11
Q
Syringomyelia
A
Cystic cavity (syrinx) in central canal of spinal cord AWC damaged first: cape-like loss of pain and temp (fine touch intact) Expansion into AMH (weakness); expansion into LH: Horners
12
Q
Tongue sensation
A
-1st and 2nd branchial arches form anterior 2/3 (sensation via CN V3, taste via CN VII)
-3rd and 4th branchial arches form posterior 1/3 (sensation and taste mainly via CN IX,
extreme posterior via CN X)
13
Q
Tongue motor innervation
A
-CN XII to hyoglossus
(retracts and depresses tongue), genioglossus (protrudes tongue), and styloglossus (draws sides of tongue upward to create a trough for swallowing)
-CN X to palatoglossus (elevates posterior tongue during swallowing)
14
Q
Astrocytes
A
Derived from neuroectoderm. Astrocyte marker: GFAP
Physical support, repair, EC K+ buffer, removal of excess NT, part of BBB, glycogen fuel reserve buffer
15
Q
Microglia
A
mesodermal, mononuclear origin
Phagocytic scavenger cells of CNS
16
Q
multinucleated giant cells in CNS of HIV patients
A
fused microglia
17
Q
Schwann cells
A
Derived from neural crest
Each Schwann cell myelinates only 1 PNS axon
18
Q
Oligodendrocytes
A
Derived from neuroectoderm
Can myelinate many axons
“Fried egg” on histology
19
Q
What is the BBB formed by?
A
Tight junctions between nonfenestrated capillary endothelial cells
Basement membrane
Astrocyte foot processes
20
Q
Function of hypothalamus
A
TAN HATS
Thirst, Adeno and Neuro hypophysis (pituitary), Hunger, ANS, Temperature, Sex
21
Q
Lateral area of hypothalamus
A
Hunger
(No lateral area: shrink laterally)
Stimulated by ghrelin,
inhibited by leptin
22
Q
Ventromedial area of hypothalamus
A
Satiety (destruction: hyperphagia)
Stimulated by leptin
23
Q
Anterior hypothalamus
A
Cooling, parasympathetic
A/C: anterior/cooling
24
Q
Posterior hypothalamus
A
Heating, sympathetic
25
Suprachiasmatic nucleus of hypothalamus
Circadian rhythm
26
Supraoptic and paraventricular nuclei of hypothalamus
Synthesize ADH and oxytocin
27
At what stage of the sleep cycle does bruxism occur?
N2 of non-REM sleep
| Delta on EEG
28
Thalamus
Major relay for all ascending sensory information except olfaction
29
Ventral Postero- Lateral nucleus of thalamus
Input from spinothalamic and dorsal columns/ medial lemniscus
Vibration, Pain, Pressure, Proprioception, Light touch, Temp
30
Ventral postero- Medial nucleus of thalamus
Input from trigeminal and gustatory pathway
| Face sensation, taste
31
Lateral geniculate nucleus of thalamus
Input from CN II
Vision; goes to calcirine sulcus
(lateral = light)
32
Medial geniculate nucleus
Input from superior olive and inferior colliculus of tectum
Hearing; goes to auditory cortex of temporal lobe
(medial = music)
33
Ventral lateral nucleus
Input from basal ganglia and cerebellum
| Motor; goes to motor cortex
34
What is the limbic system
Collection of neural structures involved in emotion, long-term memory, olfaction, behavior modulation, ANS function (the five Fs)
35
Mesocortical dopaminergic pathway
Decreased activity -> negative symptoms
36
Mesolimbic dopaminergic pathway
Increased activity: positive symptoms
37
Nigrostriatal dopaminergic pathway
Decreased activity: extrapyramidal sx
38
Tuberoinfundibular dopaminergic pathway
Decreased activity: increased prolactin and decreased libido
39
Lateral lesions of cerebellum
Affect voluntary movement of extremities (Limbs tend to fall toward ipsilateral side
40
Medial lesions of cerebellum
Involvement of Midline structures
| Bilateral motor deficits
41
Purpose of basal ganglia
Voluntary movements and making postural adjustment
42
Location of ACh synthesis
Basal nucleus of Meynert
43
Location of dopamine synthesis
Ventral tegmentum, SNc (pars compacta)
44
Location of GABA synthesis
Nucleus accumbens
45
Location of Norepinephrine synthesis
Locus ceruleus
46
Location of Serotonin synthesis
Raphe nucleus
47
Ascending spinal tracts
Dorsal and Spinothalamic
48
Function of dorsal column
Pressure, vibration, fine touch, proprioception
49
Where does the dorsal column cross?
In the medulla
50
Where is the first synapse of the dorsal column nerves?
Nucleus gracilis or cuneatus (in the ipsilateral medulla)
51
Function of spinothalamic tract
Lateral: pain, temperature
Anterior: crude touch, pressure
52
Where does the spinothalamic tract cross?
anterior white commissure
53
Where is the first synapse of the spinothalamic tract nerves?
Ipsilateral gray matter of the spinal cord
54
Where is the second synapse of the dorsal and spinothalamic tracts?
VPL of the thalamus
55
Function of lateral corticospinal tract
Voluntary movement of contralateral limbs
56
Where is the first synapse of the lateral corticospinal tract?
Cell body of anterior horn (spinal cord)
57
Where does the lateral corticospinal tract cross?
most fibers decussate at caudal medulla (pyramidal decussation)
58
What spinal level does the cremasteric reflex test?
L1, L2
59
What spinal level does the anal wink reflex test?
S3, S4
60
Clinical significance of lesion in the frontal lobe
Disinhibition and deficits in concentration, orientation, judgment; reemergence of primitive reflexes
61
Clinical significance of lesion in the frontal eye fields
Eyes look toward lesion
62
Clinical significance of lesion in the paramedian pontine reticular formation
Eyes look away from lesion
63
Clinical significance of lesion in the medial longitudinal fasciculus
Internuclear ophthalmoplegia (can occur in MS)
64
Clinical significance of lesion in the dominant parietal cortex
Agraphia, acalculia, finger agnosia, left-right disorientation
(Gerstmann syndrome)
65
Clinical significance of lesion in the nondominant parietal cortex
Agnosia of the contralateral side of the world
| Hemispatial neglect syndrome
66
Clinical significance of lesion in the hippocampus (bilateral)
Anterograde amnesia: inability to make new memories
67
Clinical significance of lesion in the basal ganglia
May result in tremor at rest, chorea, athetosis
| Parkinson and Huntington
68
Clinical significance of lesion in the subthalamic nucleus
Contralateral hemiballismus (type of chorea)
69
Clinical significance of lesion in the mammillary bodies (bilateral)
Wernicke-Korsako syndrome: Confusion, Ataxia, Nystagmus, Ophthalmoplegia, memory loss (anterograde and retrograde amnesia), confabulation, personality changes
70
Clinical significance of lesion in the amygdala (bilateral)
Klüver-Bucy syndrome: disinhibited behavior
| HSV-1 encephalitis
71
Clinical significance of lesion in the superior colliculus
Parinaud syndrome: paralysis of conjugate vertical gaze (rostral interstitial nucleus also involved)
(Stroke, hydrocephalus, pinealoma)
72
Clinical significance of lesion in the reticular activating system (midbrain)
Reduced levels of arousal and wakefulness
73
Clinical significance of lesion in the cerebellar hemisphere
Intention tremor, limb ataxia, loss of balance; damage to cerebellum: ipsilateral deficits; fall toward side of lesion
74
Clinical significance of lesion in the cerebellar vermis
Truncal ataxia, dysarthria
75
Time to irreversible brain damage and areas most vulnerable
5 minutes
| hippocampus, neocortex, cerebellum, watershed areas
76
Epidural hematoma
Middle meningeal artery
2° to skull fracture
Lucid interval
CT shows biconvex (lentiform/lens), hyperdense blood collection not crossing suture lines
77
Subdural hematoma
Bridging veins; 2° to frontal trauma
Crescent-shaped hemorrhage that crosses suture lines
Can cause midline shift; progressive neurologic signs
78
Subarachnoid hemorrhage
Rapid time course; worst HA of life
| Bloody or yellow spinal tap
79
Intraparenchymal hemorrhage
Usually due to HTN
| Typically occurs in basal ganglia and internal capsule (Charcot-Bouchard microaneurysm of lenticulostriate vessels)
80
Middle cerebral artery lesion in a stroke will affect what areas of the brain
```
Motor and sensory cortices: upper limb and face
Temporal lobe (Wernicke area)
Frontal lobe (Broca area)
```
81
Middle cerebral artery lesion in a stroke will have what sx?
Contralateral paralysis and sensory loss—face and upper limb.
Aphasia if in dominant (usually left) hemisphere. Hemineglect if lesion affects nondominant (usually right) side
82
Anterior cerebral artery lesion in a stroke will affect what areas of the brain
Motor and sensory cortices—lower limb
83
Anterior cerebral artery lesion in a stroke will have what sx?
Contralateral paralysis and sensory loss—lower limb
84
Lenticulo- striate artery lesion in a stroke will affect what areas of the brain
Striatum, internal capsule
85
Lenticulo- striate artery lesion in a stroke will have what sx?
Contralateral paralysis and/or sensory loss—face and body. Absence of cortical signs
86
Anterior spinal artery lesion in a stroke will affect what areas of the brain
Lateral corticospinal tract.
Medial lemniscus.
Caudal medulla—hypoglossal nerve
87
Anterior spinal artery lesion in a stroke will have what sx?
Medial medullary syndrome
Contralateral paralysis—upper and lower limbs.
Decreased contralateral proprioception.
Ipsilateral hypoglossal dysfunction (tongue deviates ipsilaterally)
88
Posterior inferior cerebellar artery lesion in a stroke will affect what areas of the brain
Lateral medulla: Nucleus ambiguus (CN IX, X, XI) Vestibular nuclei
Lateral spinothalamic tract, spinal trigeminal nucleus
Sympathetic fibers
Inferior cerebellar peduncle
89
Posterior inferior cerebellar artery lesion in a stroke will have what sx?
Lateral medullary (Wallenberg) syndrome
Dysphagia, hoarseness, ↓ gag reflex
Vertigo, nystagmus, ↓ pain and temperature sensation
from contralateral body,
ipsilateral face
Ipsilateral Horner syndrome Ataxia, dysmetria
90
Anterior inferior cerebellar artery lesion in a stroke will affect what areas of the brain
```
Lateral pons: Facial nucleus
Vestibular nuclei: Spinothalamic tract, spinal
trigeminal nucleus
Sympathetic fibers
Middle and inferior cerebellar peduncles
```
91
Anterior inferior cerebellar artery lesion in a stroke will have what sx?
Lateral pontine syndrome
Paralysis of face
Vertigo, nystagmus, vomiting, decreased pain and temperature sensation
from contralateral body,
ipsilateral face
Ipsilateral Horner syndrome Ataxia, dysmetria
92
Basilar artery lesion in a stroke will affect what areas of the brain
Pons, medulla, lower midbrain
Corticospinal and corticobulbar tracts
Ocular cranial nerve nuclei, paramedian pontine reticular formation
93
Basilar artery lesion in a stroke will have what sx?
“Locked-in syndrome.”
| Loss of horizontal, but not vertical, eye movements
94
Posterior cerebral lesion in a stroke will affect what areas of the brain
Occipital lobe
95
Posterior cerebral lesion in a stroke will have what sx?
Contralateral hemianopia with macular sparin
96
Central post-stroke pain syndrome
Neuropathic pain due to thalamic lesions
97
Broca aphasia
Expressive aphasia
Able to comprehend but not speak fluently
Broca area in inferior frontal gyrus of frontal lobe. Patient
appears frustrated, insight intact
98
Wernicke aphasia
Receptive aphasia
Able to speak fluently but not understand others
Wernicke area in superior temporal gyrus of temporal lobe
99
Conduction aphasia
Can be caused by damage to arCuate fasciculus.
100
Global aphasia
Cannot speak or understand
| Arcuate fasciculus; Broca and Wernicke areas affected
101
Transcortical motor aphasia
Able to comprehend but not speak fluently
| Affects frontal lobe around Broca area, but Broca area is spared
102
Transcortical sensory aphasia
Able to speak fluently but not understand others
| Affects temporal lobe around Wernicke area, but Wernicke area is spared
103
Transcortical, mixed aphasia
Broca and Wernicke areas and arcuate fasciculus remain intact; surrounding watershed areas affected
104
Most common location of a berry aneurysm
bifurcations in the circle of Willis; most common is junction of ACom and ACA
105
Cluster HA
Unilateral; 15m-3h
Brief, repetitive
Periorbital pain w/ lacrimation and rhinorrhea
106
Treatment and prophylaxis for cluster HA?
Acute: sumatriptan, 100% O2 Prophylaxis: verapamil
107
Tension HA
Bilateral; >30m, constant
Steady pain
No photophobia or phonophobia
No aura
108
Migraine
Unilateral; 4-72h
Pulsating pain with
nausea, photophobia, or phonophobia; “aura”
109
Treatment and prophylaxis for tension HA?
Analgesics, NSAIDs, acetaminophen; amitriptyline for chronic pain
110
Treatment and prophylaxis for migraine HA?
Acute: NSAIDs, triptans, dihydroergotamine
Prophylaxis: lifestyle changes, β-blockers, calcium channel blockers, amitriptyline, topiramate, valproate
111
Akathisia
Restlessness and intense urge to move
| Seen in neuroleptic use or Parkinsons
112
Asterixis
Extension of wrists causes “flapping” motion
| Hepatic encephalopathy, Wilsons
113
Athetosis
Slow, snake-like, writhing movements; especially seen in the fingers
Basal ganglia lesion
114
Chorea
Sudden, jerky, purposeless movements
| Basal ganglia lesion
115
Dystonia
Sustained, involuntary muscle contractions
| Writer’s cramp, blepharospasm, torticollis
116
Essential tremor
High-frequency tremor with sustained posture
(eg, outstretched arms); worse with movement or anxious
Decreases w/ alcohol
Treat w/ non-selective β-blockers
117
Hemiballismus
Sudden, wild flailing of 1 arm +/− ipsilateral leg
| Contralateral subthalamic nucleus lesion
118
Intention tremor
Slow, zigzag motion when pointing/extending toward a target
| Cerebellar dysfunction
119
Myoclonus
Sudden, brief, uncontrolled muscle contraction
| Common in metabolic abnormalities such as renal and liver failure
120
Resting tremor
Uncontrolled movement of distal appendages
Substansia nigra lesion
"pill rolling"
121
Parkinson disease sx
Tremor (pill-rolling tremor at rest)
Rigidity (cogwheel)
Akinesia (or bradykinesia) Postural instability
Shuffling gait
122
Parkinson disease etiology
Loss of dopaminergic neurons (ie, depigmentation) of substantia nigra pars compacta
Lewy bodies: composed of α-synuclein (intracellular eosinophilic inclusions)
123
Huntington disease sx
Symptoms manifest between ages 20 and 50: chorea, athetosis, aggression, depression, dementia (sometimes mistaken for substance abuse)
124
Huntington disease etiology
AD(CAG) repeat on chromosome 4
Atrophy of caudate and putamen with ex vacuo ventriculomegaly
↑ dopamine
↓ GABA and ACh
Neuronal death via NMDA-R binding and glutamate excitotoxicity
125
Alzheimer disease risk factors
Down syndrome: APP on 21
ApoE2: ↓ risk of sporadic form
ApoE4: ↑ risk of sporadic form
APP, presenilin-1: familial forms (10%) with earlier onset
126
Alzheimer disease histology
Widespread cortical atrophy
Narrowing of gyri and widening of sulci
Senile plaques in gray matter: extracellular β-amyloid core; may cause amyloid angiopathy
Neurofibrillary tangles
Loss of cholinergic neurons in nucleus basalis of Meynert
127
Frontotemporal dementia (Pick disease) sx
Early changes in personality and behavior (behavioral variant), or aphasia (primary progressive aphasia)
May have associated movement disorders
128
Frontotemporal dementia (Pick disease) histology
Frontotemporal lobe degeneration
| Inclusions of hyperphosphorylated tau (round Pick bodies) in the cortex
129
Lewy body dementia histology
Intracellular Lewy bodies primarily in cortex
130
Vascular dementia
Due to multiple arterial infarcts and/or chronic ischemia
| Step-wise decline in cognitive ability with late- onset memory impairment
131
Creutzfeldt-Jakob disease
Rapidly progressive (w to mo) dementia with myoclonus (“startle myoclonus”)
Periodic sharp waves on EEG
↑ 14-3-3 protein in CSF
Spongiform cortex
132
Idiopathic intracranial HTN (pseudotumor cerebri) cause and risk factors
Increased ICP w/ no cause
| Risk factors: female gender, obesity, vitamin A excess, tetracycline, danazol
133
Idiopathic intracranial HTN (pseudotumor cerebri) sx?
HA, diplopia (CN VI palsy), no change in mental status. Papilledema on fundoscopy
LP: ↑ opening pressure and HA relief
134
Idiopathic intracranial HTN (pseudotumor cerebri) treatment
weight loss, acetazolamide, topiramate, invasive procedures for refractory cases (eg, repeat LP, CSF shunt, optic nerve sheath fenestration)
135
Communicating hydrocephalus
Decreased CSF absorption by arachnoid granulations
| Increased ICP, papilledema, herniation
136
Normal pressure hydrocephalus
Affects the elderly; idiopathic
Does not result in increased subarachnoid space volume
Expansion of ventricles distorts fibers of corona radiata: triad of urinary incontinence, ataxia, and cognitive dysfunction (wet, wobbly, wacky)
Characteristic magnetic gait (feet appear stuck to floor)
137
Noncommunicating hydrocephalus
Structural blockage of CSF circulation within ventricular system
138
Ex vacuo ventriculomegaly
Appearance of increased CSF but actually decreased brain tissue
139
Osmotic demyelination syndrome (central pontine myelinolysis)
Acute paralysis, dysarthria, dysphagia, diplopia, LOC; "Locked in"
Massive axonal demyelination in pontine white matter
Caused by overly rapid correction of hyponatremia (Low to high; your pons will die)
140
Multiple sclerosis cause
Autoimmune inflammation and demyelination of CNS
141
Lhermitte phenomenon
Neck flexion precipitates sensation of electric shock running down spine (seen in MS and chemo)
142
Multiple sclerosis disease course
Most often affects women in their 20s and 30s; more common in Caucasians living farther from equator; HLA-DR2
Relapsing and remitting
143
MS sx
Optic neuritis (sudden loss of vision resulting in Marcus Gunn pupils), INO, hemiparesis, hemisensory symptoms, bladder/bowel dysfunction
144
Charcot triad of MS
Scanning speech
Intention tremor (also Incontinence and Internuclear ophthalmoplegia)
Nystagmus
145
MS histology and labs
Increased IgG and MBP in CSF
Oligoclonal bands
Periventricular plaques
146
Treatment of MS
Disease-modifying therapies (β-interferon, glatiramer, natalizumab)
Acute: IV steroids
147
Treatment for acute inflammatory demyelinating plyradiculopathy
(Guillain-Barre most common subtype)
| plasmapheresis and IV ig
148
Charcot-Marie-Tooth disease cause
Also known as hereditary motor and sensory neuropathy (HMSN)
| defective production of proteins involved in the structure and function of peripheral nerves or the myelin sheath
149
Charcot-Marie-Tooth disease sx
Foot deformities (pes cavus, hammer toe), lower extremity weakness (foot drop) and sensory deficits
150
Krabbe disease cause
AR lysosomal storage disease due to deficiency of galactocerebrosidase: destruction of myelin sheath; galatocerebrosidase build up in macrophages
151
Krabbe disease sx
Peripheral neuropathy, developmental delay, optic atrophy, globoid cells
152
Metachromatic leukodystrophy
AR lysosomal storage disease: arylsulfatase deficiency; build up of myelin
153
Progressive multifocal leukoencephalopathy
Demyelination of CNS due to destruction of oligodendrocytes
| Assoc w/JC virus
154
Adrenoleukodystrophy
X-linked
Disrupts metabolism of very-long-chain fatty acids d/t impaired addition of coenzyme A
FA accumulates and damages adrenal glands and white matter
155
Sturge-Weber syndrome (encephalotrigeminal angiomatosis) cause
Congenital, noninherited, developmental anomaly of neural crest derivatives due to somatic mosaicism for an activating mutation in one copy of the GNAQ gene
156
Sturge-Weber syndrome (encephalotrigeminal angiomatosis) sx
- port-wine stain of the face
- ipsilateral leptomeningeal angioma: seizures/ epilepsy; intellectual disability
- episcleral hemangioma: increased IOP -> early glaucoma
157
Tuberous sclerosis cause
TSC1/TSC2 mutation on chromosome 16. Autosomal dominant, variable expression
158
Tuberous sclerosis sx
```
HAMARTOMAS: Hamartomas in CNS and skin
Angio fibromas
Mitral regurgitation
Ash-leaf spots
cardiac Rhabdomyoma (Tuberous sclerosis)
autosomal dOminant
Mental retardation (intellectual disability)
renal Angiomyolipoma
Seizures
Shagreen patches
Increased subependymal giant cell astrocytomas and ungual fibromas
```
159
Neurofibromatosis type I (von Recklinghausen disease) cause
Mutation in NF1 tumor suppressor gene on chromosome 17: codes for neuro bromin, a negative regulator of RAS
Autosomal dominant, 100% penetrance
160
Neurofibromatosis type I (von Recklinghausen disease) sx
Café-au-lait spots, cutaneous neurofibromas, optic gliomas, pheochromocytomas, Lisch nodules (pigmented iris hamartomas)
161
Neurofibromatosis type II cause
Mutation in NF2 tumor suppressor gene on chromosome 22
| Autosomal dominant
162
Neurofibromatosis type II sx
bilateral acoustic schwannomas, juvenile cataracts, meningiomas, and ependymomas
163
von Hippel-Lindau disease cause
Deletion of VHL gene on chromosome 3p
| Autosomal dominant
164
von Hippel-Lindau disease sx
HARP: Hemangioblastomas (high vascularity with hyperchromatic nuclei) in retina, brain stem, cerebellum, spine
Angiomatosis (cavernous hemangiomas in skin, mucosa, organs)
bilateral Renal cell carcinomas
Pheochromocytomas
165
Glioblastoma multiforme
```
Adult primary brain tumor
grade IV astrocytoma
highly malignant, cerebral hemispheres, butterfly
Astrocyte origin, GFAP ⊕
"Pseudopalisading”
```
166
Oligodendroglioma
```
Adult primary brain tumor
Rare, slow growing
Frontal lobes; “Chicken-wire” capillary pattern
“Fried egg” cells
Often calcified
```
167
Meningioma
Adult primary brain tumor
occurs near surfaces of brain and in parasagittal region; dural attachment
may present with seizures or focal neurologic signs
Arachnoid cell origin; whorled; psammoma
168
Hemangioblastoma
Adult primary brain tumor
Cerebellar; assoc w/ VHL
Can produce erythropoietin: 2° polycythemia
Blood vessel origin
169
Schwannoma
Adult primary brain tumor
Classically at cerebellopontine angle
Localized to CN VIII in internal acoustic meatus → vestibular schwannoma
Schwann cell origin: S-100 ⊕
170
Pilocytic (low-grade) astrocytoma
Childhood 1° brain tumor
Well circumscribed, found in posterior fossa
Glial cell origin, GFAP ⊕ Rosenthal fibers- eosinophilic, corkscrew fibers
171
Medulloblastoma
Childhood 1° brain tumor
Most common malignant brain tumor in childhood
Involves cerebellum
Can compress 4th ventricle, causing noncommunicating hydrocephalus; drop metastases
Homer-Wright rosettes, small blue cells
172
Ependymoma
Childhood 1° brain tumor
Found in 4th ventricle; hydrocephalus
Ependymal cell origin; perivascular rosettes
173
Craniopharyngioma
Childhood 1° brain tumor
Most common childhood supratentorial tumor
Derived from remnants of Rathke pouch
Calcification is common
Cholesterol crystals found in “motor oil”—like fluid within tumor
174
Pinealoma
Childhood 1° brain tumor
Tumor of pineal gland
Parinaud syndrome (compression of tectum → vertical gaze palsy)
Precocious puberty in males
175
Sx of CN V motor lesion
Jaw deviates toward side of lesion due to unopposed force from the opposite pterygoid muscle
176
Sx of CN X lesion
Uvula deviates away from side of lesion
| Weak side collapses and uvula points away
177
Sx of CN XI lesion
Weakness turning head to contralateral side of lesion (SCM)
| Shoulder droop on side of lesion (trapezius)
178
Sx of CN XII lesion
LMN lesion
| Tongue deviates toward side of lesion
179
Facial nerve LMN lesion
paralysis of upper and lower muscles of facial expression, hyperacusis, loss of taste sensation to anterior tongue
180
Middle ear bones name and function
Ossicles (malleus, incus, stapes); conduct and amplify sound from eardrum to inner ear
181
Conductive hearing loss
```
Abnormal Rinne (bone > air)
Weber to affected ear
```
182
Sensorineural hearing loss
```
Normal Rinne (air > bone)
Weber to unaffected ear
```
183
Noise-induced hearing loss
Damage to stereociliated cells in organ of Corti
| Loss of high-frequency hearing first
184
Presbycusis
Aging-related sensorineural hearing loss (higher frequencies) due to destruction of hair cells at cochlear base
185
Cholesteatoma
Overgrowth of desquamated keratin debris within middle ear space
erode ossicles, mastoid air cells -> conductive hearing loss
186
Conjunctivitis
Inflammation of the conjunctiva; redeye
187
Hyperopia
“farsightedness”
Eye too short for refractive power of cornea and lens -> light focused behind retina
Correct with convex (converging) lenses
188
Myopia
“nearsightedness”
Eye too long for refractive power of cornea and lens -> light focused in front of retina
Correct with concave (diverging) lens
189
Astigmatism
Abnormal curvature of cornea: different refractive power at different axes
Correct with cylindrical lens
190
Presbyopia
Aging-related impaired accommodation
191
Cataract
opacification of lens
192
Glaucoma
Optic disc atrophy with characteristic cupping
| Elevated IOP
193
Uveitis
Innflammation of uvea
194
Age-related macular degeneration
Causes distortion (metamorphopsia) and eventual loss of central vision (scotomas)
195
Miosis
Constriction, PSNS:
1st neuron: Edinger-Westphal nucleus to ciliary ganglion via CN III
2nd neuron: short ciliary nerves to sphincter pupillae muscles
196
Mydriasis
Dilation, sympathetic
197
Marcus Gunn pupil
Afferent pupillary defect: optic nerve damage or severe retinal injury.
Decreased bilateral pupillary constriction when light is shone in affected eye relative to unaffected eye
198
CN III damage: motor
ptosis, “down and out” gaze
199
CN III damage: PSNS
diminished or absent pupillary light reflex, “blown pupil” often with “down-and-out” gaze
200
CN IV damage
Eye moves upward, particularly with contralateral gaze
201
CN VI damage
Medially directed eye that cannot abduct
202
Cavernous sinus syndrome
variable ophthalmoplegia, decreased corneal sensation, Horner syndrome and occasional decreased maxillary sensation
CN VI is most susceptible to injury
203
Internuclear ophthalmoplegia
Lesion in medial longitudinal fasciculus: conjugate horizontal gaze palsy
When CN VI nucleus activates ipsilateral lateral rectus, contralateral CN III nucleus does not stimulate medial rectus to contract
Seen in MS
204
Suvorexant
Orexin (hypocretin) receptor antagonist
| For insomnia
205
Ramelteon
Melatonin receptor agonist, binds MT1 and MT2 in suprachiasmatic nucleus
For insomnia
206
Drugs used in Huntington disease
Tetrabenazine and reserpine: inhibit VMAT
| Haloperidol: D2 receptor antagonist
207
Riluzole
Treatment for ALS that modestly increases survival by decreasing glutamate excitotoxicity via an unclear mechanism
208
Memantine
NMDA-r antagonist
| For Alzheimer
209
MOA of local anesthetics
Block Na+ channels by binding to specific receptors on inner portion of channel
210
Baclofen
Activates GABAb receptors at spinal cord level, inducing skeletal muscle relaxation.
211
Cyclobenzaprine
Centrally acting skeletal muscle relaxant
| Structurally related to TCAs, similar anticholinergic side effects
212
Pentazocine
κ-opioid receptor agonist and μ-opioid receptor weak antagonist or partial agonist
Analgesia for moderate to severe pain
213
Butorphanol
κ-opioid receptor agonist and μ-opioid receptor partial agonist; produces analgesia
214
Tramadol
Very weak opioid agonist; also inhibits 5-HT and norepinephrine reuptake
215
Frog-like appearance of a fetus
anencephaly
216
What is impaired in anencephaly?
Amniotic fluid swallowing: polyhydraminos
217
Cerebral aquaduct stenosis
Stenosis of channel that drains CSF from 3rd into 4th ventricle; accumulates in ventricular space
218
Most common cause of hydrocephalus in a newborn
Cerebral aquaduct stenosis
219
Histology of acute neuronal injury
Red neurons; 12-24hrs
| Cell body shrinkage, pyknosis, loss of Nissle bodies, eosinophilia
220
Axonal reaction
Increased protein synthesis, axonal sprouting, peripheral displacement of nucleus
221
Astrocyte injury
Gliosis; nuclei prominent and vesicular with expansion into cytoplasm
222
Alzheimer type II astrocyte
Gray matter cell with large nucleus and pale chromatin
| Seen in longstanding hyper-ammonia: liver dz, Wilson's, urea cycle disorder
223
Werdnig-Hoffman Disease
AR; Degeneration of AMH
224
Amyotrophic Lateral Sclerosis
Degenertive disorder with UMN (lateral corticospinal tract) and LMN (AMH)
Atrophy and b/l hand weakness - early signs
NO sensory loss
SOD mutation in familial cases (most are spontaneous)
225
Friedreich Ataxia
Degeneration of cerebellum and spinal cord
Loss of vibration and proprioception, LE weakness, ↓ DTRs
GAA repeat; frataxin gene regulates iron in mitochondria
Assoc w/ hypertrophic cardiomyopathy
226
Most common cause of meningitis in adults and elderly
S. pneumo
227
Infarct of pyramidal neurons in the cerebral cortex leads to what
(layer 3, 5, 6)
| Laminar necrosis
228
Lacunar stroke
2° to hyaline arteriolosclerosis
| Involved lentriculstriae vessels (from the MCA)
229
Pure motor stroke
Internal capsule
230
Pure sensory stroke
thalamus
231
What kind of stroke leads to liquefactive necrosis?
Ischemic
232
When do red neurons appear in a stroke
12-24 hours
233
Intracerebral hemorrhage
Into brain parenchyma; usually basal ganglia
Rupture of Charcot-Bouchard of lentriculstriae vessels
2° to HTN
234
Subarachnoid hemorrhage
Bleed into subarachnoid space; only cause of blood on bottom of brain
Xanthochromia on LP
Berry aneurysm, usually at branch points of ACA
235
Subacute Sclerosing Panencephalitis
D/t measles
| Viral inclusion in neurons and oligodendrocytes
236
Excessive correction of hypernatremia
Cerebral edeama or herniation (from high to low, your brain will blow)
