Neuro Flashcards
(293 cards)
1
Q
How to read a CT
A
2
Q
Why should we get a head CT?
A
To prevent unnecessary irradiation to orbits (especially lenses) and reduce artifact from dental fillings, slices are taken at an angle to the base of the skull.
3
Q
What are the indications for a non-contrast CT head?
A
Acute mental status changes, Stroke and stroke-like symptoms, Dementia, Trauma to brain, Suspected subarachnoid hemorrhage (SAH), Recurrent headaches/migraine, Seizures
4
Q
What appears hypodense (dark) on a non-contrast CT head?
A
Air (ie sinuses), water (CSF), Chronic SDK/Hygromas
5
Q
What appears isodense on a non-contrast CT head?
A
Normal brain. Gray matter (lighter gray), white matter (darker gray)
6
Q
What appears hyperdense (bright/white) on a non-contrast CT head?
A
Metal (ex: aneurysm clips), iodinated contrast, calcium, hemorrhage
7
Q
What appears white on a non-contrast CT head?
A
Bone, Pineal gland, Choroid plexus, Falx and tentorium
8
Q
What appears gray on a non-contrast CT head?
A
Gray matter (lighter), White matter (darker)
9
Q
What appears black on a non-contrast CT head?
A
CSF
10
Q
Non-contrast CT Head-Blood
A
11
Q
What is this pathology?
A
on left, subdural hemorrhage from a patient on warfarin and on the right is a subdural hemorrhage with drainage.
Abnormal head CT
White: New blood andMetal
Gray: Old blood
Black: Air
Findings:
- Midline shift
- Edema
- Mass
- Atrophy
12
Q
What is this pathology?
A
Epidural hemorrhage
Neurological damage related to mass effect
Biconvex and hyperdense
13
Q
What are the 4 types of brain bleeds?
A
Epidural hematoma, Subdural hematoma, Subarachnoid Hemorrhage, Intracerebral Hemorrhage
14
Q
What is the etiology of Epidural Hemorrhage/Hematoma?
A
High impact trauma. Usually with associated skull fracture.
15
Q
What age group is typically affected by Epidural Hemorrhage/Hematoma?
A
Typically, young adult.
16
Q
What are the common presentations of Epidural Hemorrhage/Hematoma?
A
Headache. Localizing signs related to mass effect. Loss of consciousness.
17
Q
What are the CT findings for Epidural Hemorrhage/Hematoma?
A
Hyperdense biconvex mass aka lentiform. Usually bright white but can have darker areas from active bleeding. Don’t tend to cross suture lines.
18
Q
What is this pathology?
A
Epidural hematoma
Biconvex and hyperdense
19
Q
What is this pathology?
A
Grayish indicates active bleeding
Biconvex and hyperdense
20
Q
What is this pathology?
A
Subdural hematoma with drainage
21
Q
What is this pathology?
A
Subdural hematoma with drainage placement and air bubble
On the right
22
Q
What is this pathology?
A
Traumatic subdural hematoma
Crescent on the left side from an acute bleed
23
Q
Subdural hemorrhage/hematoma (SDH) Etiology
A
Trauma. “Shaken baby syndrome”
24
Q
Subdural hemorrhage/hematoma (SDH) presentation
A
Difficult to assess in cases of pediatric abuse as pt generally cannot speak for themselves. Change in behavior
N/V. Abnormal movements. Seizure activity
25
What is this pathology?
Traumatic subarachnoid hemorrhage with contusion
Swelling on the outside of the skull
26
Subdural hemorrhage/hematoma (SDH) CT finding
Hyperdense crescent shape
27
What is this pathology?
Subarachnoid hemorrhage
28
What is this pathology?
White lines in the mid part of the brain
Aneurysm that seems to have ruptured leading to the subarachnoid hemorrhage
29
What is this pathology?
Intracerebral hemorrhage
30
Intracerebral hemorrhage etiology
**Primary
Chronic hypertension**
Amyloid angiopathy
Secondary
Vascular malformations
Neoplasms
Hemorrhagic conversion
Drug abuse: cocaine use and methamphetamines
31
Intracerebral hemorrhage age
More often > 55 years
32
Intracerebral hemorrhage presentation
Sudden onset focal neurologic deficit
33
Intracerebral hemorrhage CT finding
Hyperdensity within the parenchyma
34
What is this pathology?
Normal CT brain
35
What is this pathology?
Subdural hemorrhage (crescent shaped) - on warfarin
Midline shift from normal symmetry.
36
What is this pathology?
Metastatic renal cell carcinoma to brain
The darker area around the metastasis is edema associated with the mass
37
What is edema?
Collection of additional fluid within the white matter
Brain’s response to an insult.
38
Edema etiology
Tumor
Trauma
Hypoxia
Infection
Metabolic derangements
39
Edema CT findings
Increased low density
Darker gray areas where should be lighter gray
**Loss of gray/white matter differentiation**
40
What is atrophy?
Some brain volume decrease expected with increased age
Atrophy is decreased brain volume more than expected for age
**Common finding in neurocognitive disorders**
brain tissue is not touching the edge of the skull
41
What is this pathology?
Cerebral atrophy
42
What is this pathology?
Normal brain CT
43
What is this pathology?
Normal 50-year old female
44
What is this pathology?
Cerebral atrophy of 80 year old female
45
What is this pathology?
Glioblastoma NOS
46
What is this pathology?
Metastatic melanoma to brain
Much more common
Pineal gland right in the center
47
CT Head without contrast
Initial scan for CVa. Suspected bleed
48
CT Head with contrast
Suspected abscess or tumor. Suspected MS
49
What is the pathology?
Nocardia brain abscess
50
Most common causes of tumors
1. primary
2. metastatic disease
51
What is the etiology of primary tumors?
Primary tumors are tumors that originate in the tissue where they are found.
52
What is metastatic disease?
Metastatic disease refers to cancer that has spread from the original site to other parts of the body.
53
How does tumor incidence relate to age?
Tumor incidence increases with age.
54
What are common presentations of tumors?
Common presentations include headache, altered mental status (AMS), adult-onset seizures, and incidental findings.
55
What are the CT findings for tumors?
Tumors can have a variety of appearances on CT scans.
56
What is the etiology of abscesses?
Abscesses can arise from direct extension of cranial infections, penetrating head wounds, or hematogenous spread.
57
What are common presentations of abscesses?
Common presentations include headache, nausea/vomiting (N/V), altered mental status (AMS), seizures, and personality changes.
58
What are the CT findings for abscesses?
Abscesses typically appear as ring-enhancing lesions (often called double-ringed) and can be difficult to distinguish from some brain tumors; MRI may be needed for better clarification.
59
What are the indications for CTA of the head/neck?
Indications include when vascular abnormalities/issues are in the differential, stroke (looking for occlusion), aneurysm including dissection, AV malformations, and stenotic lesions.
60
What is this pathology?
Normal CTA of the head and neck - adult
61
What is this pathology?
Normal CT Head
62
What is this pathology?
Normal CT neck
63
What is this pathology?
Normal CT cerebral angiography
64
What is this pathology?
Critical carotid stenosis
65
What is this pathology?
Proximal right MCA M1 Segment embolic occlusion
66
What are the indications for MRI of the brain?
Confirmation of stroke, Suspected intracranial tumor/mass lesion, Concern for infection, Neurologic deficits, Chronic headache, Seizure disorder
67
What are the limitations for MRI of the brain?
Longer test (20-40 minutes), Less available, Claustrophobic pts can’t tolerate, Contraindicated for pts with metal/implanted devices
68
What are the planes for MRI of the brain?
Planes: Axial, Coronal, Sagittal
69
Sequences for brain MRI
Sequences: T1, T2, FLAIR, DWI
70
What does T1 weighted MRI of the brain show?
Bright: Fat (Bone Marrow), Contrast, Subacute hemorrhage (Slow flowing blood)
Gray: Gray matter darker, White matter lighter
Dark: Bone-cortex, Water (CSF, Edema), Chronic hemorrhage
71
What does T2 weighted MRI of the brain show?
Bright: Fat (Bone Marrow), Water (CSF, Edema), Hyperacute and chronic hemorrhage
Gray: Gray matter lighter, White matter darker, Subacute hemorrhage
72
What is this pathology?
Normal brain MRI
73
What is this pathology?
Normal brain MRI
74
What is this pathology?
Normal brain MRI
75
What is this pathology?
Primary CNS lymphoma (cerebellar)
76
What is this pathology?
Normal FLAIR brian MRI
77
What is this pathology?
Normal DWI brain MRI
78
What is this pathology?
Primary CNS lymphoma (cerebellar) on DWI view
79
FLAIR
Fluid Attenuation Inversion Recovery. **Same as T2, except fluid is darker. Useful in looking for edema or inflammation**
Also helps with identifying diseases of the white matter like MS
80
DWI
Diffusion Weighted Imaging. Shows how easily water moves around. Restricted diffusion noted in CVA, abscess, and cellular tumors—appear bright
81
What is this pathology?
Subacute Posterior Cerebral Artery Infarct
T2, FLAIR
82
What is this pathology?
Subacute Posterior Cerebral Artery Infarct
DWI
83
What is this pathology?
Nocardia Brain Abscess
T1
84
What is this pathology?
Subacute Posterior Cerebral Artery Infarct
85
What is this pathology?
Nocardia Brain Abscess
86
What is this pathology?
Nocardia Brain Abscess
DWI
87
What is this pathology?
Glioblastoma
T1
88
What is this pathology?
Glioblastoma
T2, FLAIR
89
What is this pathology?
Glioblastoma
DWI
90
What is this pathology?
Normal brain MRA
91
What are the indications for MRA?
When vascular abnormalities/issues are in the differential, stroke (looking for occlusion), aneurysm including dissection, AV malformations, stenotic lesions.
92
What are the indications for CT spine?
Acute trauma of spine, evaluation when MRI contraindicated, chronic back pain.
93
What is the purpose of non-contrast CT in spine evaluation?
Evaluate for fractures.
94
What is the purpose of contrast CT in spine evaluation?
Suspected abscess or tumor, suspected MS.
95
What is the purpose of a CT Myelogram?
Evaluate for spinal canal stenosis, tumors encroaching on spine.
96
What has largely supplanted CT Myelogram?
MRI.
97
What is the pathology?
CT without contrast
Burst fracture
98
What is the pathology?
CT with contrast
Vertebral osteoblastoma
99
What is the pathology?
CT myelogram
Severe lumbar spinal canal stenosis
100
What is the pathology?
T1
101
What is the pathology?
T2
102
What is the pathology?
STIR sequence
Bone: Dark
Bone Marrow: Intermediate/dark
Spinal Cord: Intermediate
Intervertebral Disc: Intermediate/bright
CSF: Bright
103
Indications for MRI of the spine
Back pain, Bilateral neurologic deficits, Degenerative disc disease, Spinal tumors, Incontinence, Suspected infection
104
CSF shows WBC 600,000 (mostly neutrophils), protein 450, high opening pressure, and low glucose
Bacterial meningitis
105
CSF has RBC 100,000 in tube 1 and RBC 1,000 in tube 4
Traumatic lumbar puncture
106
CSF shows elevated protein, few WBCs, and oligoclonal bands
Multiple sclerosis
107
CSF shows WBC 25,000 (mostly lymphocytes), protein 48, and elevated glucose
Viral meningitis
108
A patient with sudden onset of right face/arm weakness and speech issues
Left MCA stroke
109
A patient with blurred/painful right eye 6 months ago that resolved, and new onset left arm numbness/tingling
Multiple sclerosis
110
A patient with pain in multiple joints, worse in the morning. Joints are swollen and hot
Rheumatoid arthritis
111
A patient with sudden onset of a swollen, hot, very painful right knee. No other joints hurt
Septic arthritis (or gout)
112
A patient who complains of lower back pain and stiffness. States his father had the same thing at his age
Ankylosing spondylitis
113
A patient with a facial rash that developed at the beach, multiple joint aches, and fatigue
Systemic lupus erythematosus (SLE)
114
A patient with gradually worsening bilateral leg weakness who now has developed urinary incontinence
Spinal cord compression
115
A patient who presents with vomiting, headache, and fever. States she had a sinus infection 1 week ago
Bacterial meningitis
116
A patient who is unresponsive in the ER, and no family / friends are available, and no prior information in the chart
Initial approach: treat for hypoglycemia, overdose, or stroke
117
A patient who presents with a new onset seizure
New-onset seizure disorder (evaluate for epilepsy or secondary cause)
118
A patient who complains of a headache that is worse in the morning, and has woken him from sleep for the past 3 days
Brain tumor
119
A patient who complains of muscle weakness in the late afternoon and evening, and now is having trouble keeping her eyes open
Myasthenia gravis
120
A patient who presents with sudden onset left face/arm/leg paresis. CT head non-contrast shows no abnormalities
Early ischemic stroke
121
Where is CSF produced?
Choroid plexus
122
What is the purpose of CSF?
Circulates through intracranial ventricular system as well as cranial and spinal subarachnoid spaces
123
What is the normal volume of CSF?
Normal volume is 90-200 mL
124
At what rate is CSF produced?
Produced at a rate of 20 mL/hr. Secretion and reabsorption by arachnoid villi balance to keep CSF pressure < 15 cm H2O
125
What is CSF?
Water-like solution with similar substances as plasma (i.e. electrolytes, proteins, nutrients). Usually at equal or lower concentrations than plasma
126
What are the functions of CSF?
Provide nutrition, removes waste products, protect CNS
127
What regulates the composition of CSF?
Composition of CSF is regulated by blood brain barrier. Illness or infection can disrupt the blood brain barrier
128
What is the blood brain barrier?
Cellular structural system to separate brain cells from direct communication with blood stream. Protects the CNS from infection and maintains homeostasis by regulating what crosses from blood to CSF
129
What are the indications to look at the CSF?
Cerebral hemorrhage, infection (Meningitis, Encephalitis, Neurosyphilis), CNS autoimmune disease, demyelinating disorders, metastatic or primary brain or spinal cord neoplasm
130
How do we assess CSF?
Lumbar puncture - needle is introduced through the skin between vertebra of the lumbar spine to collect CSF from the spinal canal
131
What are the contraindications to doing a lumbar puncture?
Bleeding disorder/anticoagulated, high intracranial pressure. Consider CT prior to LP with: AMS, Papilledema, Seizure activity, Focal neurologic symptoms
132
How is CSF assessed?
Multiple tubes are collected as part of lumbar puncture. Additionally, can assess opening pressure at start of procedure
133
What does CSF look like?
Each tube is used for different tests as appropriate: Tube 1 - Chemistry (glucose, protein), Tube 2 - Hematology (cell count and differential), Tube 3 - Microbiology (Gram stain and culture), Tube 4 - Reserve or Cytology
134
How do we order CSF analysis?
Tubes must be labeled in order they are collected. You must be specific about what you want ordered. The exception is color of fluid, which is generally provided as part of the report.
135
What are the available tests for CSF analysis?
Cell count with differential, protein, glucose, Gram stain and culture, Enzyme Immunoassay (EIA)/PCR for specific organisms
136
Who collects CSF for analysis?
Emergency Department, Neurology, Interventional Radiology. If someone other than you is collecting, you need to specify if you want opening pressures obtained as this has to be done at the time of the puncture.
137
What are the normal values for CSF?
Opening pressure: 5-20 cm H2O (or 50-200 mm H2O), Color: Clear, colorless, Protein: 15-45 mg/dL, Glucose: 45-85 mg/dL (> 50% of plasma level), Cell Count: < 5 WBCs/mm3, < 3 granulocytes/mm3, < 5 RBCs/mm3, Differential: Predominantly lymphocytes
138
What is the accepted range for upper limit of normal CSF opening pressure?
Accepted range for upper limit of normal is 180-200 mm of H2O (18-20 cm of H2O). For ClinLab test use 200 mm of H2O
139
What would indicate a too high opening pressure?
Mass, infection, intracranial bleeding, blockages in circulation of CSF
140
What would indicate a too low opening pressure?
Dehydration, CSF leak
141
CSF- Appearance
Evaluation of color and clarity before and after centrifugation.
Xanthochromic is typically from old blood.
Red/Pink is typically from trauma like traumatic tap
142
How can we tell if a patient has a subarachnoid hemorrhage?
143
What does xanthochromic CSF look like?
144
What does Turbid CSF look like?
Pus type appearance
145
RBCs in CSF
Typically not present (0-5/mL)
> 5/mL indicative of intracranial/spinal hemorrhage or traumatic tap*
146
Normal CSF usually has how many cells in it?
It is typically free of cells
147
WBCs in CSF
0-5 mononuclear/mL, predominantly lymphocytes
> 3 granulocytes/mL is abnormal
148
CSF cells
149
What is the normal amount of protein in the CSF?
Normal: 15-45 mg/dL (< 1% of normal serum protein levels)
150
Why do protein molecules generally not cross the blood-brain barrier?
Protein molecules are too big to cross the blood-brain barrier.
151
What is the albumin/globulin ratio in CSF?
The albumin/globulin ratio is higher in CSF.
152
Can albumin cross the blood-brain barrier?
Yes, albumin is small enough to cross the blood-brain barrier.
153
What does elevated protein and elevated cell count in CSF indicate?
It indicates infection.
154
What does elevated protein without elevated cell count in CSF suggest?
It suggests a tumor or CNS degenerative disease.
155
What are oligoclonal bands and their significance in MS?
Oligoclonal bands are seen in 95% of MS patients but can be present in other disorders. Must order this specifically to look for it (because it is an ELISA).
156
What should be done in a traumatic spinal tap regarding RBCs and WBCs?
For every 1000 RBCs/mm3, subtract 1 WBC/mm3.
157
How should protein levels be corrected in a traumatic spinal tap?
For every 1000 RBCs/mm3, subtract 1 mg/dL from protein.
158
Normal protein levels in CSF (mg/dL)
50-300
## Footnote
Associated conditions include viral meningitis, SDH, cerebral tumor, multiple sclerosis, and neurosyphilis.
159
Elevated protein levels in CSF (> 300 mg/dL)
Bacterial meningitis, TB meningitis, spinal tumor, Guillen-Barre syndrome
## Footnote
These conditions are associated with significantly elevated protein levels.
160
Normal CSF glucose levels (mg/dL)
45-80
## Footnote
Considered normal if > 50% of serum blood glucose level is checked within 60 minutes of exam.
161
CSF glucose levels in bacterial and fungal infections
Generally decreased. Normal glucose does not rule out infeciton, but just makes it less likely
## Footnote
Bacteria consume glucose, leading to lower levels.
162
Direct smear staining of CSF - Gram stain
Used for detecting bacteria.
163
Direct smear staining of CSF - Acid fast stain
Used for detecting tuberculosis.
164
Direct smear staining of CSF - India ink
Used for detecting Cryptococcus, particularly in HIV/AIDS or immunocompromised patients.
165
Specimen collection for CSF analysis
Should be collected prior to initiating antibiotics if possible.
166
Culture of centrifuged sediment of CSF
Gold standard for meningitis diagnosis. PCR panels are being used more now
Fungal cultures are separate request
167
Sensitivity of culture for herpes simplex virus
80 to 90 percent
## Footnote
Can take five to seven days to become positive.
168
Fungal cultures positivity rate for Cryptococcus neoformans
More than 95 percent.
169
Fungal cultures positivity rate for candidal meningitis
66 percent.
170
Latex agglutination in CSF analysis
Rapid detection of bacterial antigens, low specificity, sensitivity varies.
171
PCR in CSF analysis
High sensitivity and specificity for certain organisms.
172
PCR sensitivity for herpes simplex virus type 1, Epstein-Barr virus, and enterovirus
100 percent.
173
Lactate levels in CSF
If lactate > 35 mg/dL, infection is likely bacterial.
## Footnote
Prior administration of antibiotics reduces clinical accuracy.
174
CSF cytology utility
Useful in evaluation of CNS/spinal tumors. Need at least 10 mLs of CSF.
175
CSF summary table
176
What are the most common pathogens by age in bacterial meningitis?
Neonates: Group B strep
Older Adults: Strep pneumo
177
What is the most common pathogen in neonates (<1 month)?
Group B Streptococcus (Streptococcus agalactiae)
178
What is the second most common pathogen in neonates (<1 month)?
Escherichia coli (especially K1 strain)
179
What is the most common pathogen in children (>1 month – 18 years)?
Streptococcus pneumoniae
180
What is the second most common pathogen in children (>1 month – 18 years)?
Neisseria meningitidis
181
What is the most common pathogen in adolescents (10–19 years)?
Neisseria meningitidis
182
What is the second most common pathogen in adolescents (10–19 years)?
Streptococcus pneumoniae
183
What is the most common pathogen in older adults (>50 years)?
Streptococcus pneumoniae
184
What is the second most common pathogen in older adults (>50 years)?
Listeria monocytogenes
185
What are the most common pathogens in viral meningitis?
Enteroviruses, Coxsackie, Echovirus, Herpes viruses, HSV-2, Varicella zoster, HIV, Arboviruses
## Footnote
Arboviruses are transmitted by mosquitoes, ticks, and sandflies.
186
What viral pathogens are most common in the summer and fall and in pediatrics in viral meningitis?
Enteroviruses, Coxsackie, Echovirus, Herpes viruses, HSV-2, Varicella zoster
## Footnote
Must have had infection previously to develop meningitis.
187
What are some common miscellaneous pathogens in viral meningitis?
Syphilis (T. pallidum), Lyme disease (B. burgdorferi), Cryptococcal meningitis, Coccidiomycosis
## Footnote
Cryptococcal meningitis is associated with HIV or immunosuppressed individuals, and Coccidiomycosis is endemic to the southwest US.
188
What is this pathology?
Normal EEG
189
What is this pathology?
Abnormal EEG
190
What is this pathology?
Tonic Clonic Seizure. The whole body is typically involved. Variable across all leads
191
What is this pathology?
Focal Seizure
192
What is this pathology?
Hepatic Encephalopathy
slowed background with triphasic waves
193
What are the indications for an EMG and Nerve conduction study?
Generally performed together. Indications include evaluation of weakness or paresthesias of extremities. NOT indicated for evaluation of neck pain or axial back pain. Neuromuscular monitoring under anesthesia. EMG only to guide botulinum toxin injections.
194
What is an EMG?
One or more small needles (aka electrodes) are inserted into muscle. Electrical activity is measured at rest, slight contraction, and forceful contraction. Activity at rest can indicate denervation of motor unit (i.e. ALS) or inflammation (polymyositis). Decreasing electrical activity during contraction can indicate myasthenia gravis.
195
What is a nerve conduction study (NCS)?
Electrodes are placed on skin. Speed of conduction of electrical impulse is measured. Loss of axons (i.e. diabetic neuropathy) tends to decrease amplitude. Demyelination (i.e. Guillan Barre) decreases conduction velocity of signal.
196
**What is electronystagmography (ENG)?**
Records electrical activity of eye muscles during activity, including gaze testing and tracking objects with and without moving head. Abnormal movements help localize affected area.
197
What are the contraindications to ENG?
Pacemaker.
198
What is a caloric test?
Warm water and cold water are delivered into the ear canal. Changes in temperature cause changes in the density of the endolymph fluid, which triggers the semicircular canal apparatus to send signals to the brain.
199
How can caloric testing cause nystagmus?
warm water causes eyes to deviation to contralateral side with nystagmus.
cold water causes eyes to deviate to ipsilateral side with nystagmus. Lack of nystagmus indicates brainstem lesion
200
What is Multiple Sclerosis?
Most common immune mediated inflammatory demyelinating disease of CNS
201
What is the age of onset for MS?
Relapsing-remitting type: 25-29 years old
Primary progressive type: 39-41 years old
202
What are the geographic variants of prevalence for MS?
More common in temperate climates
Less common in tropical locations
203
Are males or females more likely to get MS?
Female > Male
204
What are the risk factors for MS?
Low UV light exposure, Smoking, Obesity (especially during childhood and adolescence)
205
What is the pathophysiology of MS?
Exact cause remains unknown. Appears to be immune mediated as T cells and B cells have been found on pathologic studies of MS lesions
206
What are the pathologic features of MS?
Demyelination, axonal degeneration, and inflammation are most common findings that lead to symptomatology
207
What are the presenting symptoms for MS?
Most have focal symptoms but can range from: Limb weakness, Numbness, pins and needles, or other abnormal sensations, Urination or bowel movement problems, Vision problems-impaired vision, pain with eye movements, double vision, Gait impairment, Optic neuritis can be the presenting symptom
208
How is MS typically diagnosed?
Typically, a clinical diagnosis that can be confirmed with diagnostics
Requires involvement of >/= 2 areas of central nervous system (dissemination in space) at different time points (dissemination in time)
1. MRI will show lesions typical of MS (ovoid-oval and congregate around the ventricular areas and spaces)
2. CSF analysis will show oligoclonal bands (IgG)
209
What is the pathology?
MS
bright white ovoid lesions in the periventricular space of the brain
210
What is the pathology?
Multiple sclerosis Dawson's fingers
Lesions along the lateral ventricle
211
What is the pathology?
MS of the spine
212
How is MS diagnosed using oligoclonal bands?
Protein electrophoresis
IgG Immune response to inflammation in the CNS
Positive result is unique bands present in CSF that are not present in serum.
C= CSF S= serum
213
What is myasthenia gravis?
Autoimmune disorder affecting neuromuscular junction
214
Are males or females more likely to get myasthenia gravis?
In patients < 50 years old, female. In patients > 50 years old, slight male predominance.
215
What is the pathophysiology of myasthenia gravis?
Autoimmune attack on postsynaptic acetylcholine receptors which disrupts neuromuscular transmission. Thymus appears to play a role but uncertain exact mechanism. 15% of MG cases associated with thymoma.
216
What are the presenting symptoms for myasthenia gravis?
Ocular weakness, Diplopia, Asymmetric ptosis, Dysarthria, Change in voice, Trouble chewing, Dysphagia, Weakness and fatigue, Especially with repetitive motions.
217
What is the AChR antibody (AChR Ab) test?
Positive result is indicative of MG. In 10-20% of patients can have a negative test.
218
What is Single Fiber EMG?
Very precise testing and while most sensitive not as easy to perform as serologic testing. This is option #4 for testing for MG.
219
What two MG tests are the most sensitive?
1. AChR antibodies
2. Single-fiber EMG
3. Antibody is still the better initial choice diagnostically though.
220
Once we have a positive diagnosis for myasthenia gravis, what should we do?
Should screen for thymoma with CT Chest. Resection may be helpful in treatment.
221
Muscle-specific receptor tyrosine kinase antibody (Anti-MuSK Ab) test
Positive in a large percentage of AChR Ab negative MG patients
Clinical significance not yet defined
222
Electrodiagnostic Confirmation
Used when atypical presentation or seronegative/low positive serum titer of MG so this is step 3
NCS w/ repetitive nerve stimulation
Decreased amplitude/ impulse with each stimulation sent. This is classic for a patient with MG
223
What is this pathology?
Thymoma
224
What is dementia?
Several types. Mostly clinical diagnosis.
225
What should all patients with suspected dementia have as part of their workup?
Thyroid function tests, Vitamin levels (i.e. B12, folate, etc), CBC, CMP, CT or MRI.
226
What imaging may show atrophy in dementia patients?
CT or MRI.
227
What should be considered if there is a high suspicion for dementia?
Consider HIV or Syphilis.
228
What is the lab testing for Alzheimer's disease?
CSF analysis showing elevated phosphorylated tau proteins and decreased beta-amyloid levels.
229
What are the imaging abnormalities for Alzheimer's disease?
1. Positron emission tomography (PET) showing beta-amyloid plaques and tau protein deposits (neurofibrillary tangles).
2. MRI may show localized atrophy.
230
How do we evaluate Acute Mental Status (AMS)?
1. History is key!
2. Otherwise, initial evaluation should include CT or MRI brain
3. Routine labs: CBC, CMP, Urinalysis, ABG, Lactic Acid.
231
What routine tests are included in AMS workup?
EKG, CXR.
232
What are the steps in AMS workup?
1.Neuro imaging
2.Special tests
3.Broaden the differential
233
What special tests can be run for AMS evaluation?
Blood alcohol level, Toxicology screen, Serum osmolality and osmol gap, Ketones, Salicylate level, Ammonia.
234
What to consider if diagnosis after AMS evaluation is still unclear?
Consider Thyroid function tests, Vitamin levels, ESR and/or CRP, ANA, RPR or VRDL, CSF Analysis, Heavy metals.
235
Blood Alcohol Concentration and how to measure the amount of alcohol in the blood
236
What is the SC limit for BAC?
0.08%
237
What does a Urine Drug Screen (UDS) test for?
Screening tests for specific drugs. Each facility has its own standard. Can be blood or in some cases hair follicle.
238
What drugs does a UDS typically include?
Opiates, Benzodiazepines, Methamphetamine, Marijuana, Cocaine.
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What are the limitations of UDS regarding negative tests?
Negative tests don’t rule out other possible causes.
## Footnote
Examples of false negatives: Fentanyl, Methadone, Synthetic cannabinoids.
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What are the limitations of UDS regarding positive tests?
Positive tests can be positive for days, so not always indicative of cause of AMS. False-positives can occur from other drugs/medications.
241
What is osmolality?
Measure of number of particles in serum/plasma per unit volume. BMP/CMP usually include calculated osmolality. Measures are ordered separately.
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What is the osmalar gap?
Difference between measured and calculated serum osmolality.
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What do we know about measuring osmolality and osmolar gap?
Usually ≤ 10 mOsm/L. If > 10 mOsm/L, usually means patient ingested something that affects osmolality: Ethylene glycol, Methanol, Isopropyl alcohol, Ethanol, Toluene.
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What are the signs and symptoms of salicylate overdose?
Tinnitus, Lethargy, Confusion, Restlessness, Fever, Hyperreflexia, Seizures, Hallucinations, Stupor, Coma.
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What are the toxic levels of aspirin?
Ingestion of a total dose of 150 mg/kg in adults. Approx 7.5-10 g in adults, which equals between 30-100 aspirin tablets depending on the strength of pills and weight of the patient.
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How do we work up salicylate levels?
Call poison control if OD suspected. Tests performed immediately and if it is low or normal and toxicity is still suspected, do level again after 4 hours of ingestion. Then serial checks to document trend if needed.
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What are ketones?
From catabolism of fatty acids to form energy.
248
What is the test of choice for ketones?
Beta-hydroxybutyrate. Serum plasma levels. Elevated levels mean body is in ketosis.
249
What are the causes of high ketones?
Generally associated with DKA or starvation acidosis.
250
Can we use biomarkers for nervous system tumor diagnostics?
No definitive biomarkers. CSF would likely have elevated protein otherwise normal makeup/cells.
251
What is the imaging for nervous system tumor diagnostics?
Some have a typical appearance though can look very similar to others. Generally, we need multiple images/backgrounds to make a more educated guess. CT (non-contrasted) or MRI are usually first imaging tests performed.
252
What are the additional imaging studies for nervous system tumor diagnostics?
PET Scan, CT Myelogram, CT Chest/Abdomen/Pelvis with contrast.
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Indications for EEG
Classification and evaluation of seizures
Evaluation of brain activity during coma
Evaluation of organic causes of brain dysfunction (i.e. delirium, encephalopathy, etc.)
Evaluation of sleep disorders
Brain death determination
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Normal EEG Brain Waves
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CSF-protein
256
Structures you should be able to identify on CT:
Skull
Cerebrum
Including different lobes
Cerebellum
Pons
Lateral Ventricles
Falx cerebri
257
What is this pathology?
epidural hemorrhage
looks like a lemon. above the meniges or dura and doesnt cross the suture lines. caused by trauma
258
What is this pathology?
epidural hemorrhage
looks like a lemon. above the meniges or dura and doesnt cross the suture lines. caused by trauma
259
What is this pathology?
epidural hemorrhage
looks like a lemon. above the meniges or dura and doesnt cross the suture lines. caused by trauma
260
What is this pathology?
Subdural hematoma - with drainage
261
What is this pathology?
Subdural hematoma - with drainage
262
What is this pathology?
Traumatic subdural hematoma
263
What are the differences between the MRI sequences?
264
What is the first lab or diagnostic you wish to obtain for a 24-year-old male with loss of consciousness after a high-speed collision?
Non-contrasted CT head
265
What is the diagnosis for a 24-year-old male with loss of consciousness after a high-speed collision who underwent a non-contrasted CT head?
Epidural hematoma
266
The type of intracranial hemorrhage identified in this CT scan is often associated with what other finding?
Skull fracture
267
What other abnormality is noted on this head CT?
Midline Shift
268
What diagnostic test would be most helpful in determining the cause of the patient's symptoms in a 6-year-old boy with fever, headache, and vomiting?
Lumbar puncture
269
What is the most likely diagnosis for a 6-year-old boy with CSF results showing clear appearance, WBC count of 200/mm³ (mostly lymphocytes), protein of 60 mg/dL, and glucose of 60 mg/dL?
Viral meningitis
270
What is the most likely causative organism for viral meningitis in a 6-year-old boy?
Enterovirus
271
What is the next step for a 27-year-old obese female with changes in vision and double vision?
Refer the patient to ophthalmology for further evaluation.
272
What diagnosis would raise concern for an underlying neurologic disorder in a female with left arm weakness and a history of double vision?
Optic neuritis
273
What is your main concern for a 27-year-old female diagnosed with optic neuritis?
Multiple Sclerosis
274
What diagnostic study should be ordered first when concerned for multiple sclerosis?
MRI brain
275
Which MRI result would most likely confirm a diagnosis of multiple sclerosis?
White ovoid periventricular lesions on FLAIR sequence
276
What is the most appropriate initial imaging study for a 70-year-old male with sudden onset right-sided weakness and slurred speech?
Non contrast CT head
277
What is the next best imaging modality to confirm an acute ischemic stroke after a negative non-contrast CT?
MRI brain with DWI/FLAIR
278
Which study would best evaluate for a cardioembolic source in a patient with ischemic stroke in the left MCA territory?
Transthoracic echocardiogram (TTE)
279
Which imaging study best evaluates for large vessel occlusion amenable to thrombectomy?
CT angiography (CTA) of head and neck
280
What diagnostic test would be most useful next in identifying a potential paroxysmal source of embolism in a patient with ischemic stroke and no significant atherosclerosis or structural heart disease?
7-day event monitor
281
What is the most appropriate initial diagnostic step for a 65-year-old male with intermittent double vision and ptosis?
Acetylcholine receptor (AChR) antibody test
282
What test is appropriate to detect a rare antibody subtype if AChR antibodies are negative?
Anti-MuSK antibody testing
283
What is the next most appropriate test after a negative AChR antibody test?
Repetitive nerve stimulation
284
What additional study is essential for a patient diagnosed with myasthenia gravis to evaluate for a commonly associated condition?
CT chest
285
What is the most appropriate initial diagnostic test for a 36-year-old woman with a sudden onset of the worst headache of her life?
CT head without contrast
286
What is the most appropriate next diagnostic step if CT head shows no significant abnormality but subarachnoid hemorrhage is still suspected?
Lumbar puncture with CSF analysis
287
What finding on CSF analysis would be consistent with a subacute subarachnoid hemorrhage (SAH)?
Xanthochromia
288
What is the most appropriate initial diagnostic test for a 72-year-old male with confusion and lethargy?
Non-contrast CT head
289
What is the most appropriate next diagnostic step after an initial normal CT head?
Serum electrolytes, glucose, renal and liver function tests
290
Which test is most appropriate to rule out CNS infection in a febrile patient with altered mental status?
Lumbar puncture with CSF analysis
291
What is the best diagnostic test if a patient briefly jerks his arms and stares blankly, suggesting seizure activity?
Continuous EEG monitoring
292
What is the likely diagnosis if the EEG shows slow activity?
Metabolic encephalopathy
293
What lab test was not completed as part of the initial evaluation that you wish to obtain?
Measured serum osmolality
