(17) Nervous System Reds Flashcards
1
Q
cherry red color suggests ?
A
carbon monoxide poisoning
2
Q
Diabetic patients with small-fiber
neuropathy report
whereas those with large-fiber neuropathy experience
A
sharp, burning, or shooting foot pain
numbness and tingling or even
no sensation at all.
3
Q
Primary headaches include
secondary headaches arise from
A
migraine, tension, cluster, and trigeminal autonomic cephalagias
underlying structural, systemic, or infectious causes and may be life threatening
4
Q
Subarachnoid hemorrhage classically
presents as
Severe headache and stiff neck accompany
Dull headache increased by coughing and sneezing, especially when recurring in the same location, occurs in
A
“the worst headache of my
life” with instantaneous onset
meningitis
mass lesions from brain tumors or abscess
5
Q
Migraine headache is often preceded by
an aura or prodrome, and is highly likely
if three of the five “POUND” features are
present: Pulsatile or throbbing; Oneday
duration, or lasts 4 to 72 hours if
untreated; Unilateral; Nausea or vomiting;
Disabling or intensity causing interruption
of daily activity
A
a
6
Q
Feeling light-headed, weak in the legs, or about to faint points to presyncope from vasovagal stimulation, orthostatic hypotension, arrhythmia, or side effects from blood pressure and other medications
A
a
7
Q
Vertigo often reflects vestibular disease,
usually from peripheral causes
in the inner ear such as benign positional
vertigo, labyrinthitis, or Ménière
disease
A
a
8
Q
Ataxia, diplopia, and dysarthria are suspicious for vertebrobasilar TIA or stroke.25–30 Also consider posterior fossa tumor and migraine with brainstem aura.
A
a
9
Q
Abrupt onset of motor and sensory deficits occurs in TIA and stroke.25–30 Progressive subacute onset of lower extremity weakness suggests Guillain–Barré syndrome.31 Chronic, more gradual, onset of lower extremity weakness occurs in primary and metastatic spinal cord tumors
A
a
10
Q
Focal or asymmetric weakness has both central (ischemic, thrombotic, or mass lesions) and peripheral causes ranging from nerve injury to the neuromuscular junction disorders to myopathies
A
a
11
Q
Proximal limb weakness, when symmetric with intact sensation, occurs in myopathies from alcohol, drugs like glucocorticoids, and inflammatory muscle disorders like polymyositis and dermatomyositis. In the neuromuscular junction disorder myasthenia gravis, there is proximal typically asymmetric weakness that gets worse with effort (fatigability), often with associated bulbar symptoms such as diplopia, ptosis, dysarthria, and dysphagia
A
a
12
Q
Bilateral predominantly distal weakness,
often with sensory loss, suggests
a polyneuropathy, as in diabetes.
A
a
13
Q
Sensory changes can arise at several levels: local nerve compression or “entrapment,” seen in hand numbness in distributions specific to the median, ulnar, or radial nerve; nerve root compression with dermatomal sensory loss from vertebral bone spurs or herniated discs; or central lesions from stroke or multiple sclerosis.
A
a
14
Q
Burning pain occurs in painful sensory
neuropathies from conditions like
diabetes
A
a
15
Q
A pattern of stocking, then glove, sensory
loss occurs in polyneuropathies,
especially from diabetes; multiple
patchy areas of sensory loss in different
limbs suggest mononeuritis multiplex,
seen in diabetes and rheumatoid
arthritis
A
a
16
Q
Causes include seizures, “neurocardiogenic”
conditions such as vasovagal
syncope, postural tachycardia syndrome,
carotid sinus syncope, and
orthostatic hypotension, and cardiac
disease causing arrhythmias, especially
ventricular tachycardia and
bradyarrhythmias.37 Stroke or subarachnoid
hemorrhage are unlikely
causes of syncope unless both hemispheres
are affected
A
a
17
Q
In vasovagal syncope, the most common cause of syncope, look for the prodrome of nausea, diaphoresis, and pallor triggered by a fearful or unpleasant event, then vagally mediated hypotension, often with slow onset and offset. In syncope from arrhythmias, onset and offset are often sudden, reflecting loss and recovery of cerebral perfusion
A
a
18
Q
Common causes of acute symptomatic seizures include: head trauma; alcohol, cocaine, and other drugs; withdrawal from alcohol, benzodiazepines, and barbiturates; metabolic insults from low or high glucose or low calcium or sodium; acute stroke; and meningitis or encephalitis
A
a
19
Q
Tonic–clonic motor activity, bladder or bowel incontinence, and postictal state characterize generalized seizures. Unlike syncope, tongue biting or bruising of limbs may occur
A
a
20
Q
Epilepsy is more common in infants and
older adults. The baseline neurologic
examination is frequently normal
A
a
21
Q
Generalized epilepsy syndromes usually
begin in childhood or adolescence;
adult-onset seizures are
usually partial
A
a
22
Q
Low-frequency unilateral resting tremor, rigidity, and bradykinesia typify Parkinson disease.43,44 Essential tremors are high-frequency, bilateral, upper extremity tremors that occur with both limb movement and sustained posture and subside when the limb is relaxed; head, voice, and leg tremor may also be present
A
a
23
Q
Reversible causes of restless legs
syndrome include pregnancy, renal
disease, and iron deficiency
A
a
24
Q
The AHA/ASA report cites the wellvalidated ABCD2 scoring system for predicting ischemic stroke within 2, 7, and 90 days after TIA: Age ≥60 years, initial Blood pressure ≥140/90 mm Hg, Clinical features of focal weakness or impaired speech without focal weakness, Duration 10 to 59 minutes or ≥60 minutes, and Diabetes
A
a
25
```
Cardiovascular causes of death,
including stroke, are the greatest contributors
to the 5-year disparity in life
expectancy for African American men
compared to white men and the
4-year racial disparity for women.49
However, the racial gap in life expectancy
has recently been declining
```
a
26
```
History and careful neurologic examination
to assess level of consciousness
and focal findings are essential
for diagnosing stroke, followed by
neuroimaging to distinguish ischemic
from hemorrhagic stroke
```
a
27
```
Stroke subtypes include: TIA; ischemic—
cardioembolic, large artery atherosclerotic,
lacunar, or cryptogenic;
hemorrhagic—intracerebral, subarachnoid;
and other—dural sinus venous
thrombosis, carotid and vertebral artery
dissection, or asymptomatic aneurysm
```
a
28
The Mini-Mental State Examination,
which takes 7 to 10 minutes to administer,
is the best studied, and at a score
cutpoint of 23 to 24, has a median
likelihood ratio (LR) of 6.3 for a positive
test and 0.19 for a negative test
a
29
Loss of smell occurs in sinus conditions,
head trauma, smoking, aging,
use of cocaine, and Parkinson disease
a
30
Inspect each disc carefully for bulging
and blurred margins (papilledema);
pallor (optic atrophy); and cup
enlargement (glaucoma
a
31
```
Look for prechiasmal, or anterior,
defects seen in glaucoma, retinal
emboli, optic neuritis (visual acuity
poor); bitemporal hemianopsias from
defects at the optic chiasm, usually
from pituitary tumor; and homonymous
hemianopsias or quadrantanopsias
in postchiasmal lesions,
usually in the occipital or parietal lobe,
with associated findings of stroke
(visual acuity normal).84
```
a
32
```
If the large pupil reacts
poorly to light or anisocoria worsens
in light, the large pupil has abnormal
pupillary constriction, seen in CN III
palsy. If ptosis and ophthalmoplegia
are also present, consider intracranial
aneurysm if the patient is awake, and
transtentorial herniation if the patient
is comatose.
```
a
33
```
If both pupils react to light and anisocoria
worsens in darkness, the small
pupil has abnormal pupillary dilation,
seen in Horner syndrome and simple
anisocoria
```
a
34
```
Monocular diplopia is seen in
local problems with glasses or contact
lenses, cataracts, astigmatism, or ptosis.
Binocular diplopia occurs in CN III, IV,
and VI neuropathy (40% of patients),
and eye muscle disorders from myasthenia
gravis, trauma, thyroid ophthalmopathy,
and internuclear
ophthalmoplegia.86
```
a
35
```
Nystagmus is seen in cerebellar disease,
especially with gait ataxia and
dysarthria (increases with retinal fixation),
and vestibular disorders
(decreases with retinal fixation); and
in internuclear ophthalmoplegia
```
a
36
Ptosis is seen in 3rd nerve palsy (CN III),
Horner syndrome (ptosis, miosis,
forehead anhidrosis), or myasthenia
gravis.
a
37
```
Difficulty clenching the jaw or moving
it to the opposite side suggests masseter
and lateral pterygoid weakness,
respectively. Jaw deviation during
opening points to weakness on the
deviating side
```
a
38
Look for unilateral weakness:
bilateral weakness in:
(neuro)
CN V pontine lesions
bilateral hemispheric disease
39
CNS patterns from stroke include ipsilateral
facial and body sensory loss
from contralateral cortical or thalamic
lesions; ipsilateral face, but contralateral
body sensory loss in brainstem
lesions.
a
40
Isolated sensory loss occurs in peripheral
nerve disorders, including lesions
of the trigeminal nerve (CN V).
a
41
Blinking is absent in both eyes in
Absent blinking and sensorineural hearing loss occur in
CN V lesions and on the side of weakness in lesions of CN VII
acoustic neuroma
42
Flattening of the nasolabial fold and
| drooping of the lower eyelid suggest
facial weakness
43
```
A peripheral injury to CN VII, as seen
in Bell palsy, affects both the upper
and lower face; a central lesion affects
mainly the lower face. Loss of taste,
hyperacusis, and increased or
decreased tearing also occur in Bell
palsy.8
```
a
44
In unilateral facial paralysis, the
mouth droops on the paralyzed side
when the patient smiles or grimaces.
a
45
The whispered voice test is both sensitive
(>90%) and specific (>80%)
when assessing presence or absence
of hearing loss
a
46
Excess cerumen, otosclerosis, and otitis
media cause conductive hearing
loss; presbyacusis from aging is usually
from sensorineural hearing loss
a
47
Vertigo with hearing loss and nystagmus
| typifies Ménière disease
a
48
Hoarseness occurs in vocal cord
paralysis; nasal voice in paralysis of
the palate
a
49
Difficulty swallowing suggests pharyngeal
| or palatal weakness.
a
50
The palate fails to rise with a bilateral
lesion of CN X. In unilateral paralysis,
one side of the palate fails to rise and,
together with the uvula, is pulled
toward the normal side
a
51
Unilateral absence of this reflex suggests
a lesion of CN IX, and perhaps
CN X
a
52
```
Trapezius weakness with atrophy and
fasciculations points to a peripheral
nerve disorder. In trapezius muscle
paralysis, the shoulder droops, and
the scapula is displaced downward
and laterally
```
a
53
A supine patient with bilateral weakness
of the SCM muscles has difficulty
raising the head off the pillow
a
54
Tongue atrophy and fasciculations
are present in amyotrophic
lateral sclerosis and past polio
a
55
In a unilateral cortical lesion, the protruded
tongue deviates away from
the side of the cortical lesion. In CN XII
lesions, the tongue deviates to the
weak side.
a
56
Abnormal positions alert you to conditions
such as mono- or hemiparesis
from stroke
a
57
```
Atrophy results from PNS disorders
such as diabetic neuropathy and diseases
of the muscles themselves.
Hypertrophy is an increase in bulk
with normal or increased strength;
increased bulk with diminished
strength is called pseudohypertrophy,
seen in the Duchenne form of muscular
dystrophy. Corticospinal tract injury
can cause mild atrophy due to
decreased muscle use
```
a
58
```
Furrowing between the metacarpals,
and flattening of the thenar and
hypothenar eminences (also seen in
median and ulnar nerve damage
respectively), suggest atrophy
```
a
59
```
Other causes of muscular atrophy
include motor neuron diseases, diseases
affecting the peripheral motor
system projecting from the spinal cord,
and protein–calorie malnutrition
```
a
60
Fasciculations with atrophy and muscle
weakness suggest peripheral motor
neuron disease.
a
61
Decreased resistance suggests disease
of the PNS or cerebellum, or the
acute stages of spinal cord injury.
a
62
Marked floppiness indicates
muscle hypotonia or flaccidity, usually from a peripheral motor system disorder
63
```
Spasticity is velocity-dependent
increased tone that worsens at the
extremes of range. Spasticity, seen in
central corticospinal tract diseases, is
rate-dependent, increasing with rapid
movement. Rigidity is increased resistance
throughout the range of movement
and in both directions; it is not
rate-dependent
```
a
64
```
Impaired strength or weakness is
called paresis. Absent strength is
paralysis, or plegia. Hemiparesis refers
to weakness of one half of the body;
hemiplegia refers to paralysis of one
half of the body. Paraplegia means
paralysis of the legs; quadriplegia
means paralysis of all four limbs
```
a
65
Extensor weakness is seen in peripheral
radial nerve damage, and in the
hemiplegia of CNS disease seen in
stroke or multiple sclerosis
a
66
```
A weak grip is seen in cervical radiculopathy,
median or ulnar peripheral
nerve disease, and pain from de Quervain
tenosynovitis, carpal tunnel syndrome,
arthritis, and epicondylitis
```
a
67
Weak finger abduction occurs in ulnar
| nerve disorders.
a
68
Inspect for weak opposition of the
thumb in median nerve disorders
such as carpal tunnel syndrome
a
69
```
Symmetric weakness of the proximal
muscles suggests myopathy; symmetric
weakness of distal muscles suggests
polyneuropathy, or disorders of
peripheral nerves.
```
a
70
In cerebellar disease, look for nystagmus,
| dysarthria, hypotonia, and ataxia
a
71
```
In cerebellar disease, instead of alternating
quickly, these movements are
slow, irregular, and clumsy, an abnormality
called dysdiadochokinesis.
Upper motor neuron weakness and
basal ganglia disease can also impair
these movements, but not in the same
manner.
```
a
72
Dysdiadochokinesis points to ?
cerebellar disease
73
```
In cerebellar disease, movements are
clumsy, unsteady, and inappropriately
variable in their speed, force, and
direction. In dysmetria the patient’s finger
may initially overshoot the mark,
but then reach it fairly well. An intention
tremor may appear toward the end
of the movement
```
a
74
```
In cerebellar disease, incoordination
modestly worsens with eyes closed,
indicating loss of position sense. Consistent
deviation to one side which
worsens with the eyes closed, referred
to as past pointing, suggests cerebellar
or vestibular disease
```
a
75
```
In cerebellar disease, the heel may
overshoot the knee, then oscillate
from side to side down the shin. If
position sense is absent, the heel lifts
too high and the patient tries to look.
With eyes closed, performance is poor.
```
a
76
Gait abnormalities increase risk of
| falls.
a
77
A uncoordinated gait with reeling and
instability is ataxic. Ataxia is seen in cerebellar
disease, loss of position sense,
and intoxication
a
78
Tandem walking may reveal ataxia
| that is not otherwise obvious.
a
79
Walking on toes and heels may reveal
distal leg weakness. Inability to heelwalk
is a sensitive test for corticospinal
tract damage
a
80
Difficulty hopping points to
weakness, lack of position sense,
or cerebellar dysfunction
a
81
Difficulty doing shallow knee bends
| suggests
proximal weakness
(extensors of the hip)
weakness of the quadriceps
(extensor of the knee)
or both
82
Proximal muscle weakness in the pelvic
girdle and legs causes difficulty
with both of these activities.
a
83
```
In ataxia from dorsal column disease
and loss of position sense, vision
compensates for the sensory loss.
The patient stands fairly well with
eyes open but loses balance when
they are closed, a positive Romberg
sign. In cerebellar ataxia, the patient
has difficulty standing with feet
together whether the eyes are open
or closed
```
a
84
```
Pronator drift occurs when one
forearm and palm turn inward and
down (Fig. 17-36) and is both sensitive
and specific for a corticospinal tract
lesion in the contralateral hemisphere.
Downward drift of the arm with
flexion of fingers and elbow is also
seen.89
```
a
85
```
In loss of position sense the arms drift
sideward or upward, sometimes with
writhing movements of the hands; the
patient may not recognize the displacement
and when asked, corrects
it poorly. In cerebellar incoordination,
the arm returns to its original position
but overshoots and bounces
```
a
86
Refer to specialty textbooks for discussion
of spinal cord syndromes with
crossed sensory findings, both ipsilateral
and contralateral to the spinal
cord injury
a
87
```
Meticulous sensory mapping helps
establish the level of a spinal cord
lesion and whether a more peripheral
lesion is in a nerve root, a major
peripheral nerve, or one of its
branches
```
a
88
```
A hemisensory loss pattern suggests a
lesion in the contralateral cerebral
hemisphere; a sensory level (when one
or more sensory modalities are reduced
below a dermatome on one or both
sides) suggests a spinal cord lesion
```
a
89
Symmetric distal sensory loss suggests
a diabetic polyneuropathy. You
may miss this finding unless you compare
distal and proximal sensation
a
90
```
Here, all sensation in the hand is lost.
Repetitive testing in a proximal direction
reveals a gradual return to normal
sensation at the wrist. This
pattern does not fit either peripheral
nerve damage or dermatomal loss
(see pp. 756–757). If bilateral, it suggests
the “glove” of the “stockingglove”
sensory loss of polyneuropathy,
often seen in alcoholism and diabetes
```
a
91
```
Analgesia refers to absence of pain
sensation, hypalgesia refers to
decreased sensitivity to pain, and
hyperalgesia refers to increased pain
sensitivity
```
a
92
Anesthesia is absence of touch sensation,
hypesthesia is decreased sensitivity
to touch, and hyperesthesia is
increased sensitivity
a
93
```
Vibration sense is often the first
sensation lost in a peripheral
neuropathy and increases the
likelihood of peripheral neuropathy
16-fold.8 Causes include diabetes,
alcoholism, and posterior column
disease, seen in tertiary syphilis or
vitamin B12 deficiency
```
a
94
Testing vibration sense in the trunk is
useful when identifying the level of a
cord lesion
a
95
```
Loss of position sense, like loss of
vibration sense, is seen in tabes dorsalis,
multiple sclerosis, or B12 deficiency
from posterior column disease, and in
diabetic neuropathy
```
a
96
```
If touch and position sense are normal,
decreased or absent discriminative
sensation indicates a lesion in the
sensory cortex. Stereognosis, number
identification, and two-point discrimination
are also impaired in posterior
column disease
```
a
97
Astereognosis refers to the inability to
| recognize objects placed in the hand
a
98
The inability to recognize numbers, or
graphanesthesia, indicates a lesion in
the sensory cortex
a
99
Lesions of the sensory cortex increase
the distance between two recognizable
points
a
100
Lesions of the sensory cortex impair
| the ability to localize points accurately
a
101
With lesions of the sensory cortex,
only one stimulus may be recognized.
The stimulus to the side opposite the
damaged cortex is extinguished.
a
102
```
In spinal cord injury, the sensory level
may be several segments lower than
the spinal lesion, for reasons that are
not well understood. Percussing for
the level of vertebral pain may be
helpful
```
a
103
Hyperactive reflexes (hyperreflexia) are seen in
CNS lesions of the descending corticospinal tract
- Look for associated upper motor neuron findings of weakness, spasticity, or a positive Babinski sign
104
Hypoactive or absent reflexes (hyporeflexia)
occur in lesions of the spinal
nerve roots, spinal nerves, plexuses,
or peripheral nerves. Look for associated
findings of lower motor unit disease,
namely weakness, atrophy, and
fasciculations
a
105
The slowed relaxation phase of
reflexes in hypothyroidism is often
best detected during the ankle reflex
a
106
```
Sustained clonus points to CNS disease.
The ankle plantar flexes and dorsiflexes
repetitively and rhythmically.
Clonus must be present for a reflex to
be graded
```
a
107
Abdominal reflexes may be absent in
both central and peripheral nerve
disorders
a
108
Dorsiflexion of the big toe is a positive
Babinski response (Fig. 17-61), arising
from a CNS lesion affecting the corticospinal
tract (sensitivity ∼50%; specificity
99%).96 The Babinski response
can be transiently positive in unconscious
states from drug or alcohol
intoxication and during the postictal
period following a seizure
a
109
A marked Babinski response is occasionally
accompanied by reflex flexion
at hip and knee
a
110
Loss of the anal reflex suggests a
lesion in the S2–3–4 reflex arc, seen
in cauda equina lesions
a
111
```
Inflammation in the subarachnoid
space causes resistance to movement
that stretches the spinal nerves (neck
flexion), the femoral nerve (Brudzinski
sign), and the sciatic nerve (Kernig
sign).
```
a
112
```
Neck stiffness with resistance to flexion
is found in ∼84% of patients with
acute bacterial meningitis and 21% to
86% of patients with subarachnoid
hemorrhage.97 It is most reliably present
in severe meningeal inflammation
but its overall diagnostic accuracy is
low.
```
a
113
Flexion of both the hips and knees is a
| positive Brudzinski sign
a
114
Pain and increased resistance to knee
| extension are a positive Kernig sign
a
115
```
The mechanism of this sign is similar
to the positive straight leg raise test.
Irritation or compression of a lumbar
or sacral nerve root or the sciatic
nerve causes radicular or sciatic pain
radiating into the leg when the nerve
is stretched by extending the leg
```
a
116
```
The frequency of Brudzinski and
Kernig signs in patients with meningitis
has a reported range of 5% to
60%.97 Sensitivity and specificity for
Brudzinski and Kernig signs are
reported as ∼5% and 95% in limited
study sets but are used in emerging
scoring systems and merit more systematic
investigation
```
A
117
```
Compression of the spinal nerve root
as it passes through the vertebral
foramen causes a painful radiculopathy
with associated muscle weakness
and dermatomal sensory loss, usually
from a herniated disc. More than 95%
of disc herniations occur at L4–L5 or
L5–S1, where the spine angles sharply
posterior. Look for confirming ipsilateral
leg wasting or weak ankle dorsiflexion,
which make the diagnosis of
sciatica five times more likely
```
a
118
Pain radiating into the ipsilateral leg
is a positive straight leg test for lumbosacral
radiculopathy. Foot dorsiflexion
can further increase leg pain in lumbosacral
radiculopathy, sciatic neuropathy,
or both. Increased pain when the
contralateral healthy leg is raised is a
positive crossed straight-leg raise sign.
These maneuvers stretch the affected
nerve roots and sciatic nerve
a
119
```
Sensitivity and specificity of positive
ipsilateral straight leg raise for lumbosacral
radiculopathy in patients
with sciatica are relatively low, with
an LR of only 1.5. For the crossed
straight-leg raise the LR is higher,
```
a
120
Sudden, brief, nonrhythmic flexion of
the hands and fingers followed by
recovery indicates asterixis, seen in
liver disease, uremia, and hypercapnia
a
121
```
In winging, the medial border of the
scapula juts backward (Fig. 17-66),
suspicious for weakness of the trapezius
or serratus anterior muscle (seen
in muscular dystrophy), or injury to
the long thoracic nerve.
```
a
122
```
Determining prognosis after coma is
complex and is complicated by use of
therapeutic hypothermia. Research
targets include clinical examination,
EEG patterns, serum biomarkers, and
imaging. Careful neurologic examination
remains a mainstay of prognosis,
especially after 72 hours
```
a
123
Structural lesions from stroke,
abscess, or tumor mass may lead to
asymmetrical pupils and loss of the
light reaction
a
124
In structural hemispheric lesions, the
eyes “look at the lesion” in the affected
hemisphere
a
125
In irritative lesions from epilepsy or a
unilateral pontine lesion, the eyes “look
away” from the affected hemisphere
a
126
```
In a comatose patient with absent
doll’s eye movements, the ability to
move both eyes to one side is lost,
suspicious for a lesion of the midbrain
or pons
```
a
127
No response to stimulation indicates
| brainstem injury
a
128
Two stereotypic
responses predominate: decorticate
rigidity and decerebrate rigidity
a
129
No response on one side suggests a
| corticospinal tract lesion
a
130
The hemiplegia of acute cerebral
infarction is usually flaccid at first. The
limp hand drops to form a right angle
with the wrist
a
131
A flaccid arm drops rapidly, like a rock
a
132
In acute hemiplegia, the flaccid leg
| falls more rapidly
a
133
In acute hemiplegia, the weak leg falls
rapidly into extension, with external
rotation at the hip
a
134
Meningeal signs are suspicious for
| meningitis or subarachnoid hemorrhage
a
135
Consider alcohol, liver failure, or uremia.
Note any jaundice, cyanosis, or the
cherry red color of carbon monoxide
poisoning.
Look for bruises, lacerations, or swelling.
Examine closely for hypertensive retinopathy
and papilledema, an important sign
of elevated intracranial pressure.
Corneal reflex loss occurs in coma and
lesions affecting CN V or CN VII.
Blood or cerebrospinal fluid in the nose
or the ears suggests a skull fracture; otitis
media suggests a possible brain abscess.
Tongue injury suggests a seizure.
772
