LABS FOR NEURO DISEASES Flashcards

1
Q

If the pressure proves to be very high-over____________—one should
obtain the smallest necessary sample of fluid and then,
according to the suspected disease and patient’s condition, administer mannitol or another hyperosmolar agent

A

400 mm HG

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2
Q

Dexamethasone or an equivalent corticosteroid may
generally also be given in an ___________ in order
to produce a sustained reduction in intracranial pressure

A

initial intravenous dose of

10 mg, followed by doses of 4 to 6 mg every 6 h

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3
Q

When in cisternal puncture indicated?

A

spinal block requiring a sample of

cisternal fluid or for myelography above the lesion.

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4
Q

Warming of the analgesic
by rolling the vial between the palms seems to diminish
the _______

A

burning sensation that accompanies cutaneous

infiltration.

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5
Q

The puncture is usually
easiest to perform at the L3-L4 interspace, which corresponds
in many individuals to the________

A

axial plane of the

iliac crests, or at the interspace above or below

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6
Q

______ during the insertion of

the needle indicates that it is placed too far laterally

A

Sciatic pain

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7
Q

L P has few serious complications . The most common
is _______, estimated to occur in one-third of
patients, but in severe form in far fewer.

A

headache

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8
Q

The pain is presumably the result of a _____________ from leakage of fluid at the puncture site and _____________as the patient assumes the erect posture.

A

reduction of CSF pressure

tugging on cerebral and dural vessels

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9
Q

Bleeding into the spinal meningeal or epidural
spaces after lumbar puncture can occur in patients who
are taking anticoagulants (generally with an international
normalized ratio _________, or impaired platelet function (alcoholism,
uremia) .

A

[INR] > 1 .4), have low platelet counts

<50,000/mm3

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10
Q

In the normal adult,

the opening pressure varies from ________

A

100 to 180 mm Hp, or

8 to 14 mm Hg

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11
Q

In an adult, a pressure of
________ indicates intracranial hypotension,
generally caused by leakage of spinal fluid or systemic
dehydration.

A

50 mm H20 or below

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12
Q

The presence of a spinal subarachnoid block was
in the past confirmed by jugular venous compression
_____________

A

(Queckenstedt test, which tests for a rapid rise in CSF pressure within a few seconds after application of the pressure on the vein).

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13
Q

The presence of red blood
cells imparts a hazy or ground-glass appearance; at least
________
must be present to detect this change.

The presence of
______________, depending on the amount of blood;
centrifugation of the fluid or allowing it to stand causes
sedimentation of the RBCs

A

200 red blood cells (RBCs) per cubic millimeter (mm3)

1,000 to 6,000 RBCs per cubic millimeter imparts a hazy
pink to red color

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14
Q

In subarachnoid hemorrhage, the
RBCs begin to hemolyze within a few hours, imparting
a pink-red discoloration _______

A

(erythrochromia) to the

supernatant fluid;

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15
Q

only with large amounts of venous
blood (RBC more than 100,000/mm3) will the supernatant
fluid be faintly xanthochromic due to__________

A

contamination

with serum bilirubin and lipochromes

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16
Q

The pigments that discolor the CSF following subarachnoid

hemorrhage are __________

A

oxyhemoglobin, bilirubin,

and methemoglobin

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17
Q

Oxyhemoglobin
appears within several hours of hemorrhage, becomes
maximal in approximately ________, and diminishes over
a _______

A

36 h

7- to 9-day period.

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18
Q

Bilirubin begins to appear in___________ and increases in amount as the oxyhemoglobin
decreases.

A

2 to

3 days

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19
Q

___________
(through hemoglobin breakdown products, particularly
oxyhemoglobin) also impart a yellow tint to the CSF, as
do blood clots in the subdural or epidural space of the
cranium or spinal column

A

Hypercarotenemia and hemoglobinemia

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20
Q

_________does not enter the
CSF because a low renal threshold for this pigment permits
rapid clearing from the blood

A

Myoglobin

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21
Q

During the first month of life, the CSF may contain a s mall

number of _________

A

mononuclear cells

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22
Q

The protein content of CSF from the basal cisterns is _______and that from the ventricles is ______

A

10 to 25 mg/ dL

5 to 15 mg/ dL.

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23
Q

In children, the protein concentration is somewhat

lower at each level ______

A

( <20 mg/ dL in the lumbar subarachnoid space).

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24
Q

If the serum protein concentrations
are normal, the CSF protein should increase by about __________RBCs provided that the same tube of CSF is
used in determining the cell count and protein content

A

1mg per 1,000

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25
Q

Values in the lumbar CSF of 1,000 mg/ dL or
more usually indicate a block to CSF flow; the fluid is then
deeply yellow and clots readily because of the presence of fibrinogen; a combination called _______

A

Froin syndrome

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26
Q

The gamma globulin fraction

in CSF is approximately _______ of that in serum.

A

70 percent

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27
Q

There are other notable differences between the protein
fractions of CSF and plasma. The CSF always contains a
________ and the plasma does not

A

prealbumin fraction

28
Q

The concentration of tau
protein and in particular the ratio of _________
has found use in the diagnosis of Alzheimer disease

A

tau to beta-amyloid,

29
Q

The most important
is IgG, which may exceed 12 percent of the total CSF
protein in diseases such as multiple sclerosis, ________

A

neurosyphilis,

subacute sclerosing panencephalitis and other chronic viral meningoencephalitides

30
Q

Certain enzymes that originate in the
brain, especially the brain-derived fraction of creatine
kinase (CK-BB) but also __________ are found
in the CSF after stroke, global ischemic hypoxia, or
trauma, and have been used as markers of brain damage

A

enolase and neopterin,

31
Q

Other special markers such as elevation
of the 14-3-3 protein, which has some diagnostic
significance in __________, B-microglobulin in ______________, __________ in traumatic
and other severe brain injuries, and alpha fetoprotein in
embryonal tumors of the brain

A

prion disease
meningeal lymphomatosis
neuron specific enolase

32
Q

abnormal. After
the intravenous injection of glucose, ________ are required
to reach equilibrium with the CSF; a similar delay follows
the lowering of blood glucose.

A

2 to 4 h

33
Q

Low values of CSF glucose (hypoglycorrhachia) in the presence of pleocytosis usually indicate _________

A

bacterial, tuberculous, or fungal

meningitis,

34
Q

As a rule, viral infections of the meninges and brain do not lower the CSF glucose, although low glucose values have been reported in a small number of patients with ___________

A

mumps meningoencephalitis, and rarely in patients with herpes simplex and zoster infections.

35
Q

false positive for CALAS

A

false-positive reaction is
obtained in the presence of high titers of rheumatoid factor
or antitreponemal antibodies,

36
Q

false positive for Venereal Disease Research Laboratories
(VORL) slide flocculation test and rapid plasma reagin
(RPR) agglutination tes

A

false-positive reactions may occur
with collagen diseases, malaria, and yaws, or with contamination
of the CSF by seropositive blood

37
Q

timing of highest sensitivity for PCR tests

A

These tests are most useful in the first week
of infection, when the virus is being reproduced and its
genomic material is most

38
Q

Normally, the
pH of the CSF is approximately ________somewhat lower
than that of arterial blood, which is 7.41 .

A

7.31

39
Q

The ammonia content of the CSF is __________
that of the arterial blood; it is increased in hepatic
encephalopathy, the inherited hyperammonemias, and
the Reye syndrome;

the concentration corresponds
roughly with the severity of the encephalopathy

A

one-third to onehalf

40
Q

Elevations of _________are found in all of the portosystemic
encephalopathies including hepatic coma and the
Reye syndrome.

A

glutamine

41
Q

lactic dehydrogenase,

especially isoenzymes 4 and 5, are elevated in

A

Bact Men

42
Q

___________
is also elevated in cases of meningeal tumor infiltration,
particularly lymphoma,

A

Lactic dehydrogenase

43
Q

IN CT With contrast, Intravenous contrast in generally withheld
if the glomerular filtration rate (GFR) is less than _____

A

30 mL/

min/ 1 . 73 m2;

44
Q

MRI also provides images in any plane, but i t has the

great advantage over CT in using _____

A

nonionizing energy

and providing higher resolution views

45
Q
Gradient-echo (GRE), or susceptibility
weighted imaging (SWI), is especially sensitive to blood
and its breakdown products that appear \_\_\_\_\_\_\_\_
A

hypointense

46
Q

Preferential movement of water molecules
along a particular direction, for example, parallel to white
matter tracts, is referred to as _______

A

anisotropy

47
Q

Pus-filled abscesses and hypercellular tumors
can also show DWI _________, reflecting the limitation
of free diffusion of water in these lesions

A

hyperintensity

48
Q

_______has provided a means of
detecting regions of ischemic tissue, and to monitor the
elevated blood volume in certain brain tumors

A

Perfusion imaging

49
Q

____________is a marker of neuronal integrity;
and is decreased in both destructive lesions and in
circumstances in which there is a reduction in the density
of neurons (e.g., edema or glioma that increases the
distance between neurons)

A

N-acetyl aspartate (NAA)

50
Q

_________a marker of
membrane turnover, is elevated in some rapidly dividing
tumors.

A

Choline (Cho),

51
Q

________ can be extracted from MRI
data and used as a surrogate for local cerebral metabolic
activity.

A

This blood oxygen leveldependent

(BOLD) signal

52
Q

________ a technique which has evolved from PET, uses

isotopes that do not require a cyclotron for their production

A

Single-photon emission computed tomography

(SPECT),

53
Q

Complication rate from angiography

A

Overall morbidity from
the procedure is approximately 2.5 percent, mainly in the
form of worsening of a preexistent vascular lesion or from
complications at the site of artery puncture

54
Q

___________can be performed without

contrast, using the “time-of-flight” technique.

A

MR angiography

55
Q

they allow an accurate localization of
the locus of maximal stenosis as reflected by the highest
rates of flow and turbulence

A

carotid duplex

56
Q

The transcranial Doppler uses a_______
signal that is able to pass through the calvarial bone in
adults and then receives a frequency-shifted signal from
the blood flowing in the lumen of the basal vessels

A

2-MHz pulsed

57
Q

One of the
most remarkable properties of evoked potentials is their
resistance to________, and-in comparison
with EEG activity-even damage of the cerebral
hemispheres.

A

anesthesia, sedative drugs

58
Q

The interpretation of evoked potentials (visual, auditory,

and somatosensory) is based on the ________

A

prolongation of
the latencies of the waveforms after the stimulus, the
interwave latencies, and asymmetries in timing

59
Q

light stimulus

flashing on the retina evokes a discernible waveform in the occipital lobes

A

occipital driving

response

60
Q

BAEPs are a particularly sensitive means of detecting

lesions of the _______

A

eighth cranial nerve (vestibular
schwannoma and other tumors of the cerebellopontine
angle) and of the auditory pathways of the brainstem

61
Q

___________consists of applying 5-per-second painless
transcutaneous electrical stimuli to the median, peroneal,
or tibial nerves and recording the evoked potentials (for
the upper limb) sequentially

A

SSEP

62
Q

passage points of evoked potentials

A

Erb point above the clavicle,
over the C2 vertebra,
and over the opposite parietal cortex,
and(for the lower limb) over the lumbar roots of the cauda equina, the nuclei over the cervical spine, and the opposite parietal cortex

63
Q

Delay between the stimulus site and the Erb point or the lumbar spine indicates _________

A

peripheral nerve disease

64
Q
delay from the
Erb point (or lumbar spine) to C2 implies an abnormality
in the appropriate\_\_\_\_\_\_\_\_\_
A

nerve roots or, more frequently,

in the posterior columns;

65
Q

The normal waveforms are

designated by the symbols _________

A

P (positive) and N (negative