Neuro path Flashcards
0
Q
What is anterior cord syndrome?
A
Dorsal columns are spared
UMN paralysis and loss of pain / temp below lesion
1
Q
What is Brown-Sequard and what are its symptoms?
A
Hemisection of the spinal cord
- UMN paralysis: ipsilateral below level of lession
- Ipsilateral pain / temp sensory loss below level of lesion
- CONTRALATERAL pain / temp sensory loss below level of lesion
2
Q
What are the symptoms of central cord syndrome?
A
Bilateral loss of spinothalamic tracts below lesion
UMN paralysis of upper limbs more than lower limbs
Assoc. w/ cervical injury, often -> bladder dysfunction
3
Q
Cauda Equina syndrome
A
Saddle distribution of sensory loss
LMN paralysis below lesion
4
Q
What causes superior quadrantopia?
A
lesion of Meyer’s loop: ventral projection from LGN. contains fibers representing superior visual field
5
Q
Why is there macular sparing in an infarct of PCA?
A
Macular area of visual cortex receives dual blood supply from PCA and MCA
6
Q
What is Weber’s syndrome (superior alternating hemiplegia)?
A
Lesion of rostral midbrain affecting crus cerebri and CNIII
Contralateral UMN syndrome
Ipsi CNIII palsy
Loss of consensual response when light shone in contra eye
7
Q
What is Foville’s syndrome? cause?
A
Lesion of caudal pons
CN VI and VII affected: Ipsi loss of lateral eye movement, facial expression
MLF: internuclear opthalmoplesia
Pyramidal tract: contralateral hemiparesis
Medial lemniscus: contralateral fine touch, conscious proprio, deep pressure
thrombosis of basillar artry, pontine tumor
8
Q
What is Millard-Gubler?
A
Lesion of CN VI, VII and corticospinal tract (pons)
thrombosis of paramedian branches of basillar artery
9
Q
What is Wallenberg’s syndrome?
A
Occlusion of PICA - mid medulla
Ipsi: loss of pain / temp in face (CN V)
Ipsi: Horner’s (sympathetic damage)
Ipsi: Soft palate, phraygeal paralysis, dysphagia (nucleus ambiguous of CN X)
Contra: loss of pain / temp in body (spinothalamic)
spinocerebellar tract: ataxia
10
Q
The following are indications of damage to what brain regions? Large fixed pupils Unilateral dilated pupil Mid position fixed pupil Pinpoint pupil Small pupil with ptosis and anhydrosis
A
Large fixed pupils : tectum (dorsal midbrain)
Unilateral dilated pupil: CN III paralysis
Mid position fixed pupil: midbrain
Pinpoint pupil : pons
Small pupil with ptosis and anhydrosis : sympathetic lesion (Horner’s syndrome)
11
Q
What functions are intact in a persistent vegetative state?
A
Sleep-wake
brainstem function
12
Q
When should a neurologic exam to determine brain death be performed?
A
More than 24-48 hrs. post MI or severe brain injury
24 hrs after withdrawal of sedative drugs or those that could contribute to comatose state
13
Q
What are the 2 main types of astrocytoma?
A
- Diffuse
- astrocytoma (WHO II)
- anaplastic astrocytoma (WHO III)
- glioblastoma multiforme (WHO IV)
- Pilocytic (WHO I)
14
Q
Distinguishing feature of pilocytic astrocytoma
A
Occurs in children
Macroscopic cysts
Rosenthall fibers in tumor cells (composed of alpha B crystallin)
15
Q
What is PNET? Most common form?
A
Primitive Neuroectodermal tumors
Medulloblastoma (WHO IV) is most common, usually cerebellar tumor in children.
16
Q
From what cells do mengiomas typically arise?
A
Cells of arachnoid layer - may become attached to dura
17
Q
What is the viral association with primary CNS lymphoma?
A
EBV in patients with HIV / AIDS
18
Q
Example of germ cell tumors and common locations
A
Generally arise in pineal or hypothalamus Teratoma - benign Germinoma Embryonal carcinoma Yolk sac tumor (AFP) Choriocarcinoma (HCG)
19
Q
Genetic factors associated w/ the following: Astrocytoma Oligodendroglioma Medulloblastoma Meningioma
A
Astrocytoma: TP53 ; IDH 1
Oligodendroglioma: 1p and 19q
Medulloblastoma: 17p loss ; PTCH 1
Meningioma: 22 mutation
20
Q
What is the timeframe for maximal post-infarct cerebral edema?
A
4-7 days
21
Q
What is encephalomalacia?
A
liquefaction of brain tissue following infarct: “brain softening”
22
Q
Where do lacunar infarcts most commonly occur?
A
Basal ganglia, thalamus, white matter
23
Q
What area of the hippocampus is particularly vulnerable to ischemic damage?
A
CA1: Sommer’s sector
24
possible CNS effects of chronic HTN
1. lacunar infarcts: usually basal ganglia, <1cm
2. Charcot-Buchard aneurisms: small vessel aneurisms, often in BG
3. Etat-Crible: loss of tissue w/o infarction around small BVs
* **chronic hypertensive encephalopathy / multi-infarct dementia***
25
In diffuse hypoxic / ischemic injury what cell populations are injured first?
1. Hippocampus (CA1)
2. Cerebral cortex (laminar necrosis - middle cortical layers 3-4)
3. Watershed zones
4. Purkinje cells of cerebellum
26
What is the most common type of head injury?
Blunt trauma
27
What is a diastatic fracture?
Separation along a suture line
28
What is a commuted skull fracture?
One w/ many small fragments
29
What is pneumocephalus?
Ingress of air into brain enclosure following skull fracture
30
What are symptoms of diffuse axonal injury?
LOC
Concussion
Coma, PVS, severe disability (long term)
31
What neuronal protein is upregulated following injury (DAI)?
B-APP (beta-amyloid precursor protein)
| Believed to be involved in synaptic reformation / repair
32
What is a microscopic marker of DAI?
Axonal spheroids: Spherical enlargements of disrupted axons
33
What is the prototypical cause of epidural hematoma?
Middle meningeal artery rupture w/ skull fracture
34
3 classifications of missile head injury
Depressed: Depressed fracture w/o penetration
Penetrating: missile enters cranial cavity
Perforating: In and out
35
What is the cause of post-traumatic hydrocephalus?
Blockage of arachnoid granulations
36
What is ABCD2 criteria?
Used to identify TIA patients with elevated risk of stroke
A: Age: 1 pt if 60+
B: BP: 1pt. for HTN (>140/90)
C: Clinical: 2 pts. for weakness; 1pt. for speech disturbance w/o weakness
D: Duration: 1 pt. for 10-59 min; 2pt. for 60+
D: Diabetes: 1pt. if pos
Score of 4+: justify 24-48 hr. admission
37
Signs/ Symptoms of stroke
```
Sudden (10 seconds) onset of:
Weakness
Numbness
Confusion
Speech
Vision
Headache
```
38
What is the time target for treatment of a patient presenting w/ stroke?
w/in 60 mins of arrival
39
What is the time frame goal for a patient presenting w/ stroke to see a doctor and get a CT?
Door - doctor: 10 mins
Door - CT: 25 mins
Door - CT read: 45 mins
40
basic criteria for T-PA consideration
```
18+
Ischemic stroke w/ measurable deficit
80
taking oral anticoagulants
baseline stroke scale >25
Hx of previous stroke AND diabetes
```
41
In what patient population is prophylactic anticoagulant therapy preferred to aspirin?
Afib
42
What is the INR goal for patients taking anticoagulant?
2.0-3.0
43
What patients has the FDA approved for carotid angioplasty and stenting?
High risk patients with symptomatic high-grade carotid stenosis.
Stenting carries 2x greater risk for in-hospital stroke in non-symptomatic patients copared to endarterectomy
44
What patients are candidates for CEA or CAS?
Asymptomatic: if >80% occlusion
Symptomatic: If >69% occlusion (possibly if >50%)
45
What is leptomeningitis?
Inflammation of subarachnoid space
46
What is Waterhouse - Friderichsen syndrome?
Associated with N. meningitidis meningitis
| Adrenal hemmorhage and insufficiency, purpura, septic shock (hypotension)
47
What are some causes of chronic meningitis? where is the inflammation usually concentrated?
TB, syphilis, sarcoidosis, low-grade tumor, foreign bodies
*usually Basal Meningitis - base areas of brain more than hemispheres
48
What is a serious complication of chronic meningitis?
Brain Stem infarction due to stenosis / thrombosis of basilar artery branches
49
How does HSV gain access to the CNS and what tissue tropism does it display?
access via olfactory tract
Tropism for temporal lobe (hemorrhagic necrosis of medial temporal lobes)
50
What are Cowdry type A inclusions?
Nuclear inclusions of HSV particles
51
What are 4 types of chronic viral encephalitis and causative agents?
HIV encephalopathy: HIV
Progressive Multifocal Leukoencephalopathy: JC papovirus
Subacute Sclerosing Panencephalitis: Measles
Tropical Spastic Paraparesis: HTLV-1
52
What characterizes primary HIV encephalitis?
Perivascular monocytic inflammation -> white matter damage and myelin loss
Formation of multinucleated giant cells common, though in AIDS dementia may be brain atrophy and demyelination w/o inflammatory cells
53
CSF findings in acute leptomeningitis
Opening pressure: 200-500 mm H2O (50-180 N)
Elevated protien: >50 mg/dL (15-45 N)
Low glucose: <40 mg/dL (40-85 N)
Leukocytosis (PMN)
54
When in the course of movement execution is the Basal Ganglia active?
active in preparation and execution - even in imagined movements
Act to "filter" motor program - integration of sensory and other input
have no bearing on motor decisions or basic parameters of movement
55
What are the relative roles of the Putamen and Caudate nuclei of the basal ganglia?
Putamen is motor center: innervated by somatosensory and motor cortex (clinical correlate: degenerates in Parkinson's)
Caudated is innervated by PFC: planning, memory based, psychological (early degeneration in Huntington's: cognitive and eye movement abnormalities
56
What are striosomes and matrisomes?
```
Cell groupings in striatum of BG.
Striosome: emotional and behavioral over movement (caudate)
-proj to SNc
-Substance P and Dynorphin
-GABAergic w/ D1 and D3 receptors
Matrisome: movement (putamen)
-project to direct and indirect pathways
-Enkephalin
-GABAergic w/ D2 receptors
```
57
What are the main neuron type involved in striatal output? Subtypes?
Medium Spiny Neurons - GABAergic, silent at rest.
Classified by DA receptor type:
D1: subs. P and dynorphin. to SNr and GPi. mostly striosomal
D2: Enkephalin. To GPe. Mostly matrosomal
D3: function ???
58
What are the D1 and D2 receptor families?
D1 family: D1, D5: DA is excitatory, pos. coupling to cAMP
| D2 family: D2,3,4: DA is inhibitory. neg. coupling to cAMP
59
What nucleus is disrupted in hemibalism? Huntington's?
Hemibalism: Subthalamic nucleus
Huntington's: connection from striatum -> GPe
-> decreased inhibitory input to motor cortex: HYPERKINETIC
60
Is Huntington's Disease AD or AR? What is the genetic change?
AD
CAG repeat (>30) on chromosome 4
-> caudate nucleus atrophy
61
What is Sydenham's chorea?
hypokinetic disorder associated with rheumatic fever (GAS infection)
62
Name 3 genetic dystonias
DYT1: Early onset generalized torsion dystonia 9q34, AD. Torsin-A.
DYT5 / 14: DOPA sensitive (AD: 14q22); segawa (AR: 11p15). DA deficiency.
DYT8: Paroxysmal nonkinesigenic dyskinesia 2q35 (AD) MR1
63
What is blepharospasm?
dystonic eye closure - idiopathic
64
3 features in classifying a tremor
1. Rhythm: must be regular, rate: fast / slow
2. Morphology: flex, extend, pill-roll
3. Circumstance: rest, w/ movement, postural
65
What kind of tremor is essential tremor? Genetics?
Postural tremor, 8-12 Hz
| Often AD
66
What are some treatments for essential tremor?
```
Primidone
B-blocker
Topiramate
Alprazolam
Gabapentin
DBS
```
67
What gene is associated with Wilson's disease?
13q14.3 - q21.1
Autosomal Recessive
Enccodes ATP7B: hepatic B-type ATPase
68
How do Ceruloplasmin levels correspond to Wilson's disease?
Low in 73% of cases
| Not always reduced and reduction does not correlate to disease severity
69
What other disorders are linked to Tourettes?
OCD: genetic link
ADHD: often co-occurrance
70
With what conditions is myoclonus associated?
Toxic and metabolic encephalopathy
71
What are the cardinal motor signs of Parkinsons?
```
Must display 2 for diagnosis:
cog-wheel rigidity
bradykinesia
hypokinesia
resting tremor (4-6 Hz, pill-rolling)
postural instability: flexed posture, festination and retropulsion
```
72
What cells are lost in Parkinson's and how many must be lost before symptoms manifest?
DA producing cells of SNc
| 50% loss -> motor symptoms
73
What nuclei other than SNc are affected in Parkinson's? (6 locations of Lewy Body formation)
1. SNc: DA
2. Nucleus Paranigralis: DA
3. Vagal Dorsal Motor Nucleus: NE
4. Locus Ceruleus: NE
5. Nucleus Basalis: Ach
6. Nucleus Accumbens: Serotonin
74
What are the first areas of the brain affected in Parkinson's? According to Braak staging, when do symptoms appear?
a-synuclein changes first affect medullary structures: Dorsal motor nuclei of CN IX and X and anterior olfactory nucleus with destruction ascending to meso and neocorteces
Midbrain DA symptoms at Braak stage 3 (anosmia, constipation, depression))
75
Where is the familial Parkinson's gene located?
chromosome 4
| atypical Parkinson's disease
76
What is the major component of Lewy Bodies? what is its function?
alpha-synuclein (chr. 4): 2 mutations noted. AD inheritence.
Associated with early onset (40s) and rapid progression
Complexes w/ presynaptic DA transporter enhancing DA uptake.
Overexpression may -> increased transporters
77
What protein is associated with early onset of Parkinson's and a slow disease progression?
Parkin: disease onset in 20's w/ slow progression
AR inheritence, chr 6. (E3 ubiquitin ligase, protosome regulator)
No Lewy Bodies
78
What gene is the most common cause of inherited Parkinson's Disease?
LRRK-2 (Leucine Rich Repeat Kinase-2)
AD pattern, but only 30-40% penetrance in some mutations
Mutations of GTPase and Kinase regions of protein
Indistinguishable from idiopathic PD
79
What is the MOA of Levodopa? What is it given with?
```
Crosses BBB (DA does not)
Converted to DA by Dopa Decarboxylase (DDC) in dopaminergic nerve terminals
* Given w/ Carbidopa: inhibits peripheral DDC*
```
80
What is the levodopa + carbidopa combination drug?
Sinemet
81
What is a dietary concern for people taking Sinemet?
Protein hinders absorption
82
How does the effect of levodopa change with progression of PD?
Therapeutic window narrows -> increased incidence of dyskenesias and shorter period of drug effectiveness
83
What transporter allows levodopa to cross the BBB?
Large neutral amino acid transporter (LAAN)
84
3 dopaminergic side effects associated with PD therapy (levodopa)
Dyskinesia
Hallucination (treat with clozapine or quetiapine - atypical antipsychotics)
Hedonistic Homeostatic Dysregulation: gambling, hypersexual, long walks, shopping, etc. (more in young men (early onset))
85
What is "on-off" effect seen in levodopa therapy for PD and how is it handled?
Unpredictable fluctuations in mobility and parkinsonian symptoms. not related to dose timing.
Treat: DA agonist (Apomorphine) - rapid relief
-increase frequency of doses
86
What are 2 DA antagonists that are contraindicated in PD therapy?
Metoclopramide (Reglan)
| Phenothiazine
87
Disadvantages of DA agonists compared to levodopa
```
More cognitive (hallucinations) and adverse events than l-dopa
Contraindicated w/ angina or recent MI
CYP450 interactions
```
88
What should be administered w/ apomorphine?
antiemetic
| very high incidence of N/V
89
What drugs can be given to PD patients that enable lowering L-dopa dose?
COMTi
| MAO-Bi
90
Possible advantages of MAO-Bi therapy for PD?
Lower L-dopa dose
delay starting l-dopa
may reduce oxidative stress - neuroprotective? not proven
91
What is Gerstmann's Syndrome?
Tetrad of dominant parietal lobe lesion:
1) L - R disorientation
2) Finger agnosia (difficulty naming fingers)
3) Acalcula / Anarithmetria
4) Agraphia
92
What is Anton's syndrome?
Cortical blindness w/ anosagnosia.
| May resolve via Balint's syndrome (oculomotor apraxia)
93
What is Balint's syndrome?
Lesion of occipital - parietal connection ->
occulomotor apraxia, visual ataxia, visual inattention, and sometimes facial recognition problems. Color info better preserved.
Anton may -> Balint
94
What part of the brain is affected in achromatopsia?
Inferior parietal / occipital lobe lesion
| Loss of color vision
95
What part of the brain is damaged in alexia w/o agraphia?
posterior dominant hemisphere - occipital and splenium of corpus callosum.
Associated with homonymous hemianopsia, color anomia, achromatopsia
96
What is Amnestic Syndrome?
Bilateral limbic system lesion (medial temporal and thalamus)-> mixed anterograde / retrograde amnesia
97
What is a tool that can be used to differentiate vascular from other dementias?
Modified Hachinski Ischemic score
| 7: probably vascular
98
Requirements for a diagnosis of dementia
Memory impairment plus one of:
| language, judgement, abstract thought, praxis, constructional ability, visual recognition
99
How would early Alzheimer's and Diffuse Lewy Body disease appear different on a PET scan?
AD: decreased glucose utilization in posterior cingulate gyrus and parietal cortex
DLD: decreased glucose utilization in anterior cingulate gyrus
100
Key microscopic findings in Alzheimer's disease
1. Neurofibrillary tangles: intracellular. Tau, neurofillament, B amyloid
2. Senile plaques: extracellular - disrupted neuropil and distended axons. B-amyloid core
101
What is Khachaturian criteria for diagnosis of AD?
Count number of plaques in areas of brain most affected by AD (entorhinal, parietal, insular cortices and amygdala)
55: 15+
102
What brain areas are first affected in the Cholinergic theory of AD?
Nucleus Basalis
| Locus Cerulius
103
What fragments of APP can form amyloid?
I-40 and I-42
104
Major genes involved in Alzheimer's pathology
```
B-APP: 21: early onset
APO E4: 19: assoc.
APO E2: 19: protective
PS1: 14 ; PS2: 1: GOF -> increased amyloid production
MAPT: 17: NFT
```
105
4 possible protective therapies against Alzheimers
Smoking and moderate alcohol use
NSAIDs
Estrogen replacement
Statins
106
Average survival in CJD after onset
8mos
107
What are the characteristic features of Crutzfeldt Jakob Disease?
Myoclonus, ataxia, visual disturbances
EEG: periodic sharp waves
MRI: signal abnormalities in Basal Ganglia
CSF: 14-3-3 protein (not specific)
108
What protein is involved in prion disease, what gene codes it and where is it found?
Chromosome 20
PRNP gene
PrP protein: PrP(c) is normal PrP(Sc) or (Res) is seen in disease
109
Using ATPase staining, how do Type I and II muscle fibers stain?
Type I: (non-fatigable, low glycogen, high lipid) light staining
Type II: (fatigable, high glycogen, low lipid) dark staining
110
Upon what muscular structure is the myotactic reflex arc dependent?
Muscle spindle (intrafusal fibers): encapsulated group of fibers with sensory and motor innervation. rapids stretch -> reflex contraction
111
What are the effects of strength training and aerobic training on muscle composition?
Strength: Type 2 (fatigable) fiber hypertrophy
Aerobic: Increased oxidative capacity of muscle
Disuse -> Type 2 atrophy
112
3 neurogenic muscle disorders that affect Anterior Horn Cells
1. poliomyelitis
2. amyotrophic lateral sclerosis
3. hereditary spinal muscle atrophies
113
What are the basic mechanisms of polymyositis and dermatomyositis?
PM: CD8+ cells attack muscle cells
DM: antibody or immune complex mediated microangiopathy -> muscle damage
114
What is the mechanism of steroid induced myopathy?
Probably insulin intolerance and protein catabolism -> atrophy of type 2 fibers
115
Nerve fiber classifications
a: extrafusal muscle fibers
Aa: vibration, proprioception, soft touch
gamma: intrafusal fibers
AB, Ad: sharp pain, temperature, pressure
C: pain, autonomic
116
What do increased or reduced reflexes indicate in a case of muscle weakness
Increased reflex: central lesion
| Decreased reflex: neuropathy or problem at NMJ
117
How is a demyelinating disease differentiated from an axonal disorder?
Nerve conduction studies or biopsy
118
With what disease is connexin-32 involved and how does it present?
Charcot-Marie-Tooth X
presents differently in men vs. women
Male: demyelinating neuropathy w/ intermediate conduction
Female: axonal neuropathy w/ near normal conduction
119
What is P0 associated with?
mutation may -> either demyelinating or axonal neuropathies
120
What diseases is GDA-P1 associated with?
Demyelinating: CMT4A
Axonal: CMT w/ hoarsness
121
2 examples of periodic paralysis disorders and cause of each.
Periodic paralysis: results from voltage-gated ion channel disorders
1. Hyperkalemic periodic paralysis: Na+ channel mutation
2. Hypokalemic periodic paralysis: Ca++ channel mutation
122
Infectious causes of myositis
Viral: Flu A and B, parainfluenza, coxsackie, echo, adeno
Bacterial: S. aureus, S. pyogenes (GAS)
Parasitic: toxoplasmosis, cysticercosis (taenia solium), trichinosis
123
What are some drugs known for causing myositis?
```
D-Penicillamine
Procainamide
Cimetidine
Ranitidine
Statins
Fibrates
```
124
What gene is affected in muscular dystrophy?
Xp21: dystrophin gene (X-linked)
Duchene: dystrophin is absent or severely reduced (<3% normal)
-onset in 2nd year, wheelchair by 12, death in 3rd decade.
Becker: reduced dystrophin, less severe, generally no contractures
125
What is the most common muscular dystrophy in adults?
Myotonic dystrophy (AD)
CTG repeat on 19 and another form w/ mutation on 3q
myotonia, muscular dystrophy, cataracts, frontal balding, EKG changes
Reduction in IQ
126
What is one mechanism by which corticosteroid therapy helps Myasthenia Gravis?
Increases expression of Ach receptors
127
What is neonatal myasthenia?
Transfer of maternal anti-Ach R antibodies to infant -> myasthenia gravis symptoms
128
What are 2 bedside tests that can be done to aid in diagnosis of Myasthenia Gravis?
1) Arm abduction: if held < 5 minutes, demonstrates fatigability
2) Edrophonium: anti-cholinesterase - alleviates symptoms
- have Atropine on hand in case of CV effects
129
2 antibodies involved in Myasthenia Gravis
1) anti-AchR (specific: 80-90% of pts)
| 2) anti- Muscle specific Tyrosine Kinase (40% of those w/o anti-AchR)
130
Two EMG findings in myasthenia gravis
1) : CMAP: progressive decrement w/ repeat stim due to decreased Ach release. decrease of 10% between 1st and 5th at 3Hz
2) SFEMG: Jitter: variable synaptic transmission
131
2 causes of myasthenia gravis
Thymoma
Penicllamine
no identified bacterial or viral causes
132
4 treatments for myasthenia gravis
1) Pyridostygmine: enhanced cholinergic transmission
2) prednisone / prednisolone: alternate day dosing reduces side effects
3) thymectomy
4) plasmaphoresis
133
What is Lambert Eaton?
Autoimmune disorder affecting Ach transmission
Antibodies against voltage gated Ca++ channel (VGCC)
Gait affected, autonomic dysfunciton
60% assoc. w/ small cell lung cancer
134
What occurs in lambert eaton w/ EMG?
repetitive stim -> increased response due to increased [Ca++]
135
What illnesses have been associated with Guillan-Barre
Campylobacter jejuni, Mycoplasma pneumoniae, CMV
136
What is Fisher syndrome?
Variant of Guillain-Barre
Ataxia, areflexia, opthalmoplegia
Anti-GQ1b ganglioside : found on oculomotor fibers and sensory ganglia
137
What is multifocal motor neuropathy (MMN)?
Autoimmune motor neuron disease
Asymmetric, slowly progressive weakness, begins in arms
anti GM1 ganglioside Ab
similar to ALS, but no UMN symptoms - also more treatable
Treatment: IVIg - not plasmaphoresis or steroids
138
Name 3 paraneoplastic neuromuscular syndromes
1) Paraneoplastic Cerebellar Degeneration: anti-Yo. Breast, ovarian, uterine cancers.
2) Paraneoplastic Opsoclonus - myoclonus: dancing eyes and dancing feet. anti - Ri. Childhood neuroblastoma, multiple adult tumors.
3) Paraneoplastic encephalopathy and sensory neuronopathy: anti - Hu. Small cell carcinoma
139
How is motor nerve conduction velocity calculated?
```
Using CMAP (compound motor nerve action potential)
2 stimulus points along motor nerve - timed from stimulus to muscle reaction.
Distance between 2 sites divided by difference between the 2 latencies = nerve conduction velocity
```
140
How is sensory nerve conduction velocity measured?
Distance between stim and recording site divided by latency
141
What is the H-response and what nerve is used?
H-response evaluates reflex pathway
| Only tibial nerve is used - ankle jerk reflex
142
What is F-response?
Motor nerve stimulated - antidromic conduction -> motor nucleus
~5% of motor neurons re-stimulated to send AP back down nerve -> muscle.
Delay in addition to conduction velocity / distal latency is attributed to activity in / out of spinal cord.
143
What is a test that can be done for Benign Paroxysmal Positional Vertigo?
Hallpike-Dix maneuver
turn 45 deg. in one direction, extend neck, then quickly go to lying position
If vertigo -> nystagmus
144
Differential for vertigo lasting 1 hour or less
TIA
Migraine
Panic attack
145
What is a concern in long lasting (hours to days) vertigo?
Mentrier's Syndrome: increased endolymphatic pressure
| Untreated -> low frequency hearing loss
146
How is Multiple Sclerosis diagnosed?
History - multiple lesions in space and time
CSF: pleocytosis during acute attack, increased protein (IgG), oligoclonal bands
MRI: multiple lesions
147
How does MS risk correlate with location?
Risk correlates with geographic location of residence prior to age 15.
Risk increases with increasing Northern Latitude
148
What is the genetic association with Multiple Sclerosis?
```
MHC locus on chr. 6
class II HLA-DR2, DR5, DQ6
```
149
What is Neuromyelitis Optica?
Severe form of MS that selectively affects optic nerves and spinal cord
Marker: NMO IgG : binds aquaporin 4 in astrocytic foot processes forming BBB
150
What is central pontine myelinolysis?
Myelin destruction in central pons due to overly rapid correction of hyponatremia
Avoidable!
Marked by rapid onset of quadriplegia due to bilateral damage to corticospinal tract myelin
151
What is prevention for post-herpetic neuralgia?
Preventative: Zostavax vaccine (also varivax, but not studied)
Steroids and early antivirals w/ incidence of shingles may decrease severity
152
1st and 2nd line treatments for trigeminal nerve pain
1st: Carbamazepine: VGNaC blocker. P450 inducer. induces own metabolism.
2nd: Gabapentin, Pregabalin, Tramadol, Opioids (all +/- carbamazepine)
153
What is the pathogenesis of Diabetic neuropathy?
Elevated blood glucose -> increased sorbitol production via aldose reductase -> oxidative stress -> ion channel damage and axonal shrinkage
abnormal sensory function and pain
154
What is the tiered approach to treatment of neuropathic pain?
1: Gabapentin, pregabalin, lidocaine patch
2: TCA, venlafaxine, opioids
3: other: capsaicin, topiramate, lamotrigine, valproic acid
155
List risk factors for failure of ventral induction of CNS
Trisomies 13 and 18
Maternal diabetes
ETOH
Maternal infections (toxoplasmosis, rubella, syphillis)
156
Drug of choice for absence seizures
Ethosuximide
Alternative: Clonazepam
157
Drug of choice / alterantives for partial seizures
DOC: Carbamazepine or Levetiracetam or Phenytoin
Alt: Valproic acid, Phenobarbital
158
Drug of choice for generalized seizures
Valproic acid
| Levetiracetam
