Transcript Neurology QOD review

Neurology QOD review
• A 14-year-old boy presents to your office because the side of his
face is drooping. His mother states that he complained yesterday of
decreased food taste. Today, while at school, he could not use the
microscope in science class because he couldn't close his left eye,
and his teacher noted that his smile was crooked. Physical
examination reveals no abnormalities and no vesicles in his ears.
Mental status on neurologic examination is normal, pupil responses
are normal, extraocular movements are full, and there is no
nystagmus or reported double vision. He is unable to close his left
eye or raise his left eyebrow, has decreased left-side nasolabial
folds, and cannot close his mouth to puff out his cheeks. His palate
and tongue movements are normal. Motor examination reveals
normal proximal and distal strength in both arms and normal regular
and tandem gait.
Of the following, the MOST appropriate initial diagnostic
procedure is
1. blood test for antistreptococcal
antibodies
2. brain magnetic resonance imaging
3. edrophonium (Tensilon®) test
4. no further testing
5. noncontrast head CT
Answer D
•
Acute focal or generalized weakness is a medical emergency requiring a systematic
history and neurologic examination to localize the problem. For acute focal weakness,
the problem can localize to the brain, brainstem, spinal cord, anterior horn cell, root,
nerve, junction, or muscle. Often, the physical examination can localize the problem
to one of these levels. In the case of acute unilateral facial weakness, as described
for the boy in the vignette, the typical differential diagnosis is acute facial nerve palsy
(ie, Bell palsy) or a more rostral disease process of the brainstem or brain (cerebrum,
motor cortex) such as a stroke. The key diagnostic point for facial weakness is
whether the weakness involves the entire side of the face or the face below the
forehead. A 7th nerve palsy affects all the innervated muscles, weakening or
paralyzing the entire hemi-face from forehead to chin. A lesion above the facial nerve
nucleus typically weakens the face below the forehead.
The boy described in the vignette has full left-sided facial weakness, including the
muscles in his forehead. Such findings localize to the facial nerve, and in this clinical
setting, neuroimaging is not revealing. Accordingly, no further testing is required.
When the examination localizes a problem involving facial weakness to the brain or
brainstem, brain magnetic resonance imaging (MRI) or, if MRI is not available quickly,
noncontrast head computed tomography should be obtained.
•
Facial weakness due to an acute brain process, such as a left middle cerebral artery
stroke, usually presents with involvement of both the contralateral right face and the
right hand. The brainstem, specifically the pons, is the source of the facial nerve, and
brainstem diseases can produce full hemi-facial weakness. However, due to the close
proximity of other brainstem nuclei, a brainstem lesion affecting the left face also
should affect other functions, including the left 6th nerve, which abducts the left eye.
Often, sensory and motor findings on the opposite side of the body, the so-called
"crossed signs," indicate brainstem disease.
The edrophonium/Tensilon® test involves administration of this acetylcholinesterase
inhibitor to increase acetylcholine at the neuromuscular junction and reverse
weakness. The test is used for diagnosis of myasthenia gravis. Myasthenia gravis
typically produces bilateral fatiguing weakness, particularly ptosis, as well as
weakness in other cranial nerves or generalized weakness.
Facial nerve palsy can be caused by a variety of infectious agents, but no specific
diagnostic testing is indicated in most cases. Assessment of antistreptococcal
antibodies is not helpful because streptococci do not cause facial nerve palsy.
However, in regions where Lyme disease is endemic or exposure is possible, testing
for Lyme disease may be indicated.
The American Academy of Neurology practice parameter states that oral steroids
probably are beneficial and acyclovir possibly is beneficial for treatment of facial
nerve palsy. Pediatric studies and reviews have concluded that evidence is
insufficient to recommend steroids for children. However, many clinicians recommend
administering a short course of oral prednisone for Bell palsy.
During the health supervision visit for a healthy 4-month-old boy, you
note that his head circumference is 46 cm (>98th percentile) and his
length and weight are at the 50th percentile. He has mild frontal
bossing and widely split cranial sutures. The fontanelle is flat. Arm and
leg movements, tone, and reflexes are normal. In reviewing prior
growth parameters, you note that his head circumference was at the
75th percentile at birth and the 90th percentile at 2 months.
Of the following, the MOST helpful next diagnostic procedure is
1.
2.
3.
4.
5.
electroencephalography
head ultrasonography
lumbar puncture with manometry
plain radiography of the skull
three-dimensional head CT scan
Answer B
•
The boy described in the vignette is healthy, with no abnormalities of
neurodevelopment, and his neurologic examination reveals no changes in mental
status or evidence of focal brain abnormalities or increased intracranial pressure.
However, assuming measurements are accurate, he has steadily crossed head
circumference percentiles since birth. Neuroimaging is important to determine the
reason for his crossing of percentiles. The differential diagnosis includes
hydrocephalus, arachnoid cyst, parenchymal brain lesions, subdural hematomas, and
neurodegenerative diseases. Although the most helpful high-resolution image in this
case is brain magnetic resonance imaging, sedation usually is required for such
imaging in a child of this age. In contrast, head ultrasonography through the
fontanelle can be performed quickly and with less risk and cost because sedation is
not needed. The results can be used in planning referral to neurosurgery or
neurology. Some conditions, such as an arachnoid cyst, may not require urgent
intervention, and observation suffices, with magnetic resonance imaging scheduled
for a later date.
Because the child does not have seizures, electroencephalography is not indicated.
Lumbar puncture to rule out elevated intracranial pressure is not needed because the
sutures are open. Therefore, in a chronic process, pressure will not rise to a level that
is dangerous or requires measurement. Studies of bone are not helpful. Radiography
of the skull will not provide information that affects management. Three-dimensional
computed tomography scan is helpful for assessing craniosynostosis if the child's
head shape is abnormal and fused ridges at the cranial sutures are palpable.
• A 4-year-old boy presents to the emergency department with
balance problems. He had been previously healthy, but his
walking has worsened progressively for the past 2 days, with
staggering and lurching. On physical examination, the boy is
cooperative and alert. His muscles are not tender, and his
joints are not red, swollen, or tender. His vision seems
functionally normal, but there is end-gaze nystagmus in all
directions. When sitting independently, his head and trunk
bob. His strength appears normal, and his reflexes are
normal. When asked to stand with his hands outstretched, a
symmetric tremor is evident and worsens as he approaches
the target on finger-to-nose testing. His gait is broad-based. A
urine toxicology screen reveals normal results. Brain magnetic
resonance imaging shows no tumors or other gray or white
matter lesions. Lumbar puncture shows 3 white blood cells, 2
red blood cells, protein of 20.0 g/dL, and glucose of 50.0
mg/dL (2.8 mmol/L).
Of the following, you are MOST likely to advise the child's
mother that
1. IV steroids significantly reduce recurrence
risk
2. neuroblastoma is a common cause of these
symptoms
3. repeat lumbar puncture is needed in 2 days
4. symptoms may resolve in weeks to months
5. symptoms usually resolve after antibiotics
Answer D
•
A child who experiences subacute-onset gait or balance problems should be
evaluated thoroughly in the emergency department based initially on localization
obtained through careful examination. The differential diagnosis includes structural
and immunologically mediated diseases that can be life-threatening or cause
permanent neurologic injury. The bilateral symptoms with completely normal mental
status and no somnolence described for the boy in the vignette makes a cerebral
cause less likely. The lateral end-gaze nystagmus, tremor on hand activation and
finger-to-nose testing, trunk bobbing (titubation), and broad-based gait localize the
problem to the cerebellum (Item C118). The subacute onset of such symptoms
strongly suggests acute cerebellar ataxia, which usually is acquired after infection or
immunization. Because this is a self-limited, monophasic illness, the mother can be
advised that the symptoms should resolve in weeks to months.
A repeat lumbar puncture in a few days is not likely to clarify the diagnosis. Otitis
media does not cause nystagmus and ataxia, and antibiotics are not indicated (unless
there is a concurrent bacterial infection). The recurrence risk for acute cerebellar
ataxia is low, and it is unknown whether steroids reduce the risk further. Although
clinical trials are not available to guide management, due in part to the low incidence
of this condition, many clinicians empirically treat with a short course of high-dose
steroids to reduce the duration of illness.
•
Although the time course makes a structural cerebellar or brainstem lesion unlikely
for this patient, ordering the magnetic resonance imaging is reasonable because
children in this age group may present with cerebellar and brainstem neoplasms such
as astrocytomas, pontine gliomas, primitive neuroectodermal tumors
(medulloblastomas), or ependymomas. Rarely, such a presentation may be
associated with Guillain-Barré syndrome. Therefore, specialty consultation is advised.
For children presenting with acute ataxia, the clinician should be especially vigilant for
the possibility of neuroblastoma presenting as opsoclonus myoclonus ataxia
syndrome. Case series have shown that children who have opsoclonus myoclonus
often are misdiagnosed initially as having acute cerebellar ataxia. Because
distinguishing these diagnoses clinically is challenging, specialty consultation is
advisable.
American Board of Pediatrics Content Specification:
Know the prognosis of childhood cerebellar ataxia
• A 2-year-old boy is brought to the emergency
department because he has been having episodes in
which his arms and legs become stiff, his head turns to
the side, and his jaw becomes clenched. The episodes,
which occurred in the past hour, last for 30 seconds and
resolve spontaneously. After the episodes, he is fussy
but awake and alert. His mother reports that earlier today
he had fallen off the bed but subsequently acted
normally. He is otherwise healthy and takes no
medications. His maternal grandmother has type 2
diabetes and gastroesophageal reflux, and his mother
suffers from an anxiety disorder. On physical
examination, his heart rate is 140 beats/min, respiratory
rate is 24 breaths/min, blood pressure is 100/60 mm Hg,
and oxygen saturation is 98%. All of his other physical
findings are within normal parameters.
Of the following, the MOST likely cause of this child's signs
and symptoms is
1.
2.
3.
4.
5.
epidural hematoma
glyburide ingestion
lorazepam ingestion
metoclopramide ingestion
new-onset seizure disorder
Answer D
•
The child described in the vignette is exhibiting signs of an acute dystonic reaction,
one of many neurologic manifestations that can result from toxic ingestions. Acute
dystonia is a well-recognized adverse effect of metoclopramide as well as typical and
atypical antipsychotic medications. Glyburide, an oral hypoglycemic agent, may
cause sedation and seizures related to hypoglycemia, and lorazepam, a
benzodiazepine, causes sedation and coma in overdose. An epidural hematoma is
likely to cause sedation and focal motor deficits. Finally, although differentiating an
acute dystonic reaction from a seizure may be challenging, the stereotypical
muscular activity and lack of unresponsiveness during the episodes reported for this
boy are hallmarks of acute dystonia.
•
More than 50% of all poisonings reported to the American Association of Poison
Control Centers involve children younger than 5 years of age, and although most of
these exposures are not serious, those that result in neurologic toxicity frequently
require medical intervention. Common neurologic signs and symptoms following
significant toxic exposures include seizures, coma, acute dystonia, ataxia, and
muscular abnormalities (Item C16). These neurologic effects may be related to a
direct effect on the central or peripheral nervous system or to resultant metabolic
abnormalities (eg, hypoglycemia, acidosis).
• A 10-year-old boy presents to the emergency
department with a 2-day history of progressive difficulty
with speech and coordination. On physical examination,
the restless but otherwise quiet child has a normal
mental status and eye movements. His speech is
slurred, and he cannot maintain tongue protrusion
without an in-and-out darting movement. Continuous
flowing and jerky movements occur when he holds his
hands outstretched or overhead (Item Q134). Although
his grip is strong, he cannot maintain it well because of
irregular hand and arm movements. He had a sore throat
and fever 2 months ago. You diagnose chorea.
Of the following, the MOST effective treatment for
suppressing the chorea for this boy is
1.
2.
3.
4.
5.
carbamazepine
clonazepam
haloperidol
penicillin
trihexyphenidyl
Answer C
•
The restless, continuous, involuntary movements that are irregular in direction and amplitude
described for the boy in the vignette represent classic chorea. He also has the classic "milk-maid's
grip" and "darting tongue" signs, in which a simple motor command cannot be maintained due to
choreic intrusions or involuntary relaxations (Item C134). The most common form is
poststreptococcal, immune-mediated chorea, that is, Sydenham chorea. The prior sore throat and
fever reported for the boy may have been an undiagnosed group A beta-hemolytic streptococcal
infection. This possibility should be evaluated with blood testing for two antistreptococcal
antibodies: antistreptolysin O and anti-DNAse B. Other diagnostic possibilities include chorea
associated with systemic lupus erythematosus, antiphospholipid antibody syndrome, or
hyperthyroidism.
Haloperidol is a dopamine receptor-blocking agent that also is referred to as a neuroleptic. This
high-potency antipsychotic can suppress chorea effectively, but the incidence of adverse effects is
high. Fortunately, Sydenham chorea usually is self-limited and a low dose is generally helpful.
Other antipsychotics (fluphenazine or risperidone) or dopamine-depleting agents (tetrabenazine)
also may be used. Because of the diagnostic complexity and therapeutic considerations, the boy
should receive prompt specialty consultation with a neurologist or a movement disorder specialist.
Carbamazepine is an anticonvulsant. It does not treat chorea and occasionally may induce it.
Valproic acid, another anticonvulsant, sometimes is used to suppress chorea but probably is less
effective than haloperidol. Penicillin is indicated for secondary prevention among patients who
have rheumatic fever, even with chorea as the sole manifestation. However, penicillin does not
treat the chorea. Clonazepam is a benzodiazepine that may be helpful, but sedating doses often
are required for efficacy. Trihexyphenidyl is an anticholinergic medication that may reduce
dystonia, but it tends to worsen the symptoms of Sydenham chorea.
• During the health supervision visit for a 6-weekold boy, his father expresses concern that his
son "doesn't look like" his other children. Growth
parameters are normal except for a head
circumference of 35.5 cm (less than the 5th
percentile). On physical examination, you note
that the infant does not appear to fixate or track
your face visually. There is "slip through" on
vertical suspension and "draping over" on
horizontal suspension. Deep tendon reflexes are
brisk. Moro reflex is present and brisk.
Of the following, the MOST likely cause of this infant's
hypotonia is
1.
2.
3.
4.
5.
anterior horn cell disease
congenital brain malformation
congenital myasthenic syndrome
congenital myopathy
spinal cord disease
Answer B
•
The diagnostic process for a "floppy" infant involves the same thinking process as for acute
weakness, with the primary difference being the urgency. Chronic generalized hypotonia at a
health supervision visit does not require emergency evaluation unless there is difficulty breathing.
The first step is to try to determine the responsible neurologic level, based on history and physical
examination. The brain, brainstem, spinal cord, anterior horn cell, root, nerve, junction, and
muscle should be considered systematically in each case.
Three findings for the child described in the vignette localize his problem, at least in part, to the
cerebrum. First, and most importantly, the head circumference of this 6-week-old is essentially
that of a newborn. It is important to determine by reviewing prior measurements whether head
growth has arrested or the microcephaly was present at birth. Second, the infant is not tracking
visually. Because this could be an eyeball or brainstem problem, it is important to assess the red
reflex, pupil reactions, and vestibular ocular reflex (manually move the head briskly but gently to
each side and determine if the eyes move the expected, opposite direction). In the presence of
microcephaly, cortical visual processing problems are more likely than eye or brainstem problems.
Finally, the infant's reflexes are brisk, which is usually indicative of brain pathology. Absent
reflexes point to a peripheral nervous system problem. The compilation of these findings suggests
that the most likely cause is a congenital brain malformation.
Spinal cord lesions can cause weakness and hypotonia caudal to the level of the lesion, but they
do not result in a small head or poor visual tracking. Similarly, spinal muscular atrophy/anterior
horn cell disease, congenital myasthenia (neuromuscular junction dysfunction), or congenital
myopathies would not account for this symptom complex.
• A 17-year-old girl presents with complaints of recurring
headaches that are becoming more frequent. She was
diagnosed with migraine headaches 2 years ago.
Previously she had an average of one migraine per
month, but she now has one per week. She has no
double vision, vomiting, or awakening from sleep with
headaches. Headaches can occur at any time of day, are
throbbing and bifrontal, and are associated with nausea
and phonophobia. They are relieved by nonsteroidal
anti-inflammatory drugs and by lying down in the dark.
They rarely last more than 4 hours. The adolescent and
her mother are concerned that the increased headache
frequency could be due to a brain tumor or aneurysm.
Of the following, the MOST appropriate next step is
1.
2.
3.
4.
5.
brain MRA to rule out aneurysm
brain MRI to rule out brain tumor
head CT with contrast to rule out brain tumor
LP with manometry to rule out elevated ICP
perform no diagnostic testing at this time
Answer E
•
When evaluating a child who has a headache, the first decision point is whether to
perform medical diagnostic testing, particularly neuroimaging such as head computed
tomography (CT) scan or brain magnetic resonance imaging (MRI). This decision is
based on an assessment of the likelihood of a primary headache (eg, migraine,
tension, cluster) or a secondary headache (due to disease). Primary headaches are
painful paroxysmal events occurring in isolation or, more commonly, as part of a
chronic, recurring pain disorder. No underlying lesion is causing the pain. Most
children, adolescents, and adults presenting to the primary care physician with
headache, including the girl described in the vignette, have primary headaches, and
no medical diagnostic testing is needed as part of validated standard of care. The
advantages and disadvantages of neurodiagnostic tests for a variety of conditions are
noted in (Item C6).
A family history of aneurysms may increase the risk for aneurysms (and anxiety), but
it is not an indication for neuroimaging testing for aneurysms in a patient younger
than age 30 years. However, because cigarette smoking increases the risk for
aneurysmal rupture, this is a good opportunity to remind families about the dangers of
smoking.
Most brain tumors are sporadic primary tumors or metastatic, not familial, and,
therefore, a family history of brain tumors is not an indication for neuroimaging in
most cases. In the absence of symptoms and signs of elevated intracranial pressure
or meningitis, lumbar puncture is not needed.
•
Imaging studies (CT scan, MRI, and occasionally magnetic resonance angiography),
sometimes followed by lumbar puncture with manometry, are indicated when there is
suspicion of intracranial disease (eg, tumor, aneurysm) or other medical processes,
particularly processes that increase intracranial pressure. Symptoms that may herald
the presence of secondary headache include pain awakening from sleep, pain
relieved by vomiting, and pain increased by the Valsalva maneuver. Additional
symptoms such as new binocular double vision, any focal numbness or weakness, or
loss of coordination should prompt an investigation. Secondary headaches are more
likely in the presence of abnormal signs such as papilledema, acquired (new) ocular
malalignment with double vision, stiff neck, limb weakness, or ataxia.
American Board of Pediatrics Content Specification(s): Know the values and
limitations of ancillary neurodiagnostic tests in the evaluation of a headache
• A 14-year-old boy who was diagnosed with
migraines at age 11 presents to the emergency
department with a severe migraine. For the past
2 months, he has had two to three such
headaches per week. His mother asks about
using stronger pain medications. You are
concerned about the possible complications of
medication overuse.
Of the following, the class of abortive medications that is
MOST likely to induce chronic headaches is
1.
2.
3.
4.
5.
caffeine-containing medications
isometheptene compounds
nonsteroidal anti-inflammatory drugs
opiates
triptans
Answer D
•
Opiates and barbiturates are more likely than caffeine-containing medications,
isometheptene compounds, nonsteroidal anti-inflammatory drugs (NSAIDs), or
triptans to cause chronic headaches due to overuse of medications. Medication
overuse headache is the third most common type of chronic headache after migraine
and tension headache. Most often, it results from NSAID use because NSAIDs are
the most widely used agents for headaches. However, the probability of medication
overuse headache is higher with opiates.
Medication withdrawal headache is a huge public health problem and a factor
involved in chronic daily headache for many adolescents. The only effective treatment
is withdrawal of the medication. Although less common than with opiates, medication
overuse headache may occur with over-the-counter analgesics, triptans,
ergotamines, and combination analgesics with caffeine.
Other well-known complications of medications used to treat headache include
constipation with opiates, tolerance with benzodiazepines, and gastrointestinal
distress with NSAIDs.
• A 12-year-old girl presents to the emergency
department with back pain. She had been
practicing flips on her backyard trampoline with
parental supervision and landed awkwardly.
Within 1 hour of presentation, she complains of
an inability to move her legs and numbness in
both legs. On physical examination, she has
normal upper limb strength but reduced strength
of both legs. You suspect a spinal cord injury.
Of the following, the additional clinical finding that is most
suggestive of an acute spinal cord injury in this girl is
1. ankle clonus
2. dermatomal band of sensory loss in
the trunk
3. hyperalgesia of the soles of the feet
4. hyporeflexia at the knees
5. positive Romberg sign
Answer D
•
The girl described in the vignette has sustained a spinal cord contusion from the fall.
The back pain and combination of numbness and weakness in both legs but not arms
localizes the problem to the spinal cord. In the short term after the injury, reflexes
typically are diminished, even though this is an "upper motor neuron" lesion, above
the anterior horn cell/motor neurons exiting the cord. Therefore, hyporeflexia at the
knees would be expected. Upper motor neuron signs of a positive Babinski response
(upgoing toes), ankle clonus, hyperreflexia, and spasticity all may occur in days or
weeks if there has been permanent damage to the spinal cord, but these would not
be present acutely.
Sensory symptoms and physical examination findings may be helpful in this setting to
localize the lesion along sensory pathways: skin, nerve, root, spinal cord, thalamus,
and cortex. Among the potential positive findings are tingling or shooting pains, and
negative findings may include loss of pain/temperature or vibration/proprioception in
predictable body distributions. A complete spinal cord lesion results in loss of
sensation of all modalities, from the toes up to a dermatomal level in the trunk 1 to 2
roots below the level of top of the cord lesion.
A dermatomal band of sensory loss would be expected for injury of a single nerve
exiting the cord, not a problem intrinsic to the cord. Hyperalgesia, or increased
sensitivity to pain, results from damage to peripheral nerves.
•
A Romberg test is performed by having a patient stand with feet together, touching
each other, and the examiner standing next to the patient. With eyes open, vision,
proprioception, and vestibular systems combine to allow the patient to maintain
balance. The visual system allows a patient to compensate for a mild proprioceptive
or vestibular deficit. When the eyes close, characteristic swaying and loss of balance
may occur. This positive Romberg sign may occur in spinal cord lesions when there is
a loss of posterior column/proprioceptive pathways. This test cannot be performed or
interpreted accurately when there is leg weakness, as in the girl in the vignette.
American Board of Pediatrics Content Specification(s): Recognize the clinical
manifestations of an acute spinal cord lesion
A 13-year-old girl has had 5 days of unremitting
headache that is relieved by vomiting but not sleep and 1
day of double vision. She was previously healthy and
has no history of migraine headaches, but she was
treated for otitis media 6 weeks ago. Findings on
physical examination are normal except for some
tenderness over her left mastoid. On neurologic
examination, you note normal mental status and
normally reactive pupils and vision but florid
papilledema. She cannot abduct her right eye fully and
has subjective double vision with both eyes open looking
to the right but not looking to the left or with either eye
covered. Facial sensation and movements are normally
symmetric, and the rest of the findings are normal. Head
computed tomography scan yields normal results.
Of the following, the diagnostic test or procedure that is
MOST likely to be helpful is
1.
2.
3.
4.
5.
brain magnetic resonance imaging
cerebral angiography
lumbar puncture with manometry
ocular nerve sheath fenestration
serum vitamin A measurement
Answer C
•
The girl described in the vignette has unremitting head pain that improves transiently
after vomiting but not sleep. In addition, she has a new symptom of double vision
when looking to the right, not left, an acquired ocular malalignment consistent with a
right 6th nerve palsy. The lack of facial weakness or facial sensory loss suggests that
this symptom comes from outside of the brainstem. Funduscopic examination reveals
bilateral papilledema. This complex of symptoms is characteristic of raised
intracranial pressure due to pseudotumor cerebri. Diagnosis and treatment are
needed to reduce pain and prevent visual loss.
An urgent head computed tomography (CT) scan in the emergency department
showed normal findings. This rules out hydrocephalus or a mass lesion but does not
rule out elevated intracranial pressure. The most helpful procedure to determine this
finding is a lumbar puncture with manometry. Manometry pressure measurement
should be obtained with the child in the lateral decubitus position, with legs relaxed. A
pressure greater than 20 cm H2O confirms the clinical impression of elevated
intracranial pressure and relieves the pressure. The pressure often remains low for
several days because cerebrospinal fluid drains into the soft tissues around the
lumbar puncture site. Cerebrospinal fluid studies should include assessment of
protein, glucose, and cell count. Bacterial, fungal, and Mycobacterium tuberculosis
studies as well as cytology for malignancy may be indicated in some cases.
•
The differential diagnosis of pseudotumor cerebri includes complications of obesity;
adverse effects of medications such as minocycline, isotretinoin, or steroids;
hypervitaminosis A; venous sinus thrombosis; anemia; renal failure; and
hypercalcemia.
The recent history of otitis media and current pain over the mastoid described for the
girl are consistent with mastoiditis. The cause for her pseudotumor was venous sinus
thrombosis. This may be apparent on head CT scan, but magnetic resonance
imaging (MRI) with contrast and with venography is more sensitive for detection than
head CT or routine MRI.
Cerebral angiography typically is used to characterize arterial vascular pathology.
However, this invasive procedure is undertaken infrequently because of
improvements in magnetic resonance angiography. Ocular nerve sheath fenestration
is performed occasionally as a longer term treatment for refractory pseudotumor
cerebri to reduce pressure on the eyes and preserve vision. Serum vitamin A
measurement is reasonable after lumbar puncture as part of the evaluation for
causes of intracranial hypertension.
American Board of Pediatrics Content Specification(s): Recognize the physical
characteristics of a headache due to increased intracranial pressure
•
A 10-year-old previously healthy girl
presents with subacute low back pain. In the
past 24 hours, she had "pins and needles"
tingling in her left leg and subsequently her right
leg. Six hours after the onset of the tingling, she
was unable to void urine. On physical
examination, the girl is not somnolent or
confused, but she has flaccid weakness in the
legs, absent reflexes in the legs, a sensory level
in the lower back at T9-10, diminished sensation
in the feet to pinprick and vibration, and reduced
rectal tone.
Of the following, the MOST appropriate next diagnostic test
is
1. brain MRI with contrast
2. computed tomography scan of the
spine
3. electroencephalography
4. lumbar puncture
5. spinal MRI with contrast
•
•
Answer E
The symptom complex of escalating back pain, leg numbness, leg weakness, and
urinary retention described for the girl in the vignette mandates urgent evaluation.
The loss of leg strength and rectal tone as well as a sensory level documented on the
physical examination are pathognomonic for a spinal cord lesion. Emergency imaging
of the spine with magnetic resonance imaging (MRI) is warranted
Computed tomography scan of the spine is appropriate for detecting lesions in bone,
but it is less sensitive than MRI, particularly for intramedullary (intracord) processes.
MRI is the preferred imaging modality for inflammatory conditions such as
infectious/postinfectious/inflammatory myopathies; vascular conditions such as
strokes, hematomas, vascular malformations; neoplasms; and trauma. If an
inflammatory lesion is seen, brain MRI with contrast should be obtained to look for
demyelination in brain, cerebellum, brainstem, and optic nerves.
A problem in the brain, specifically hydrocephalus, can cause leg weakness, but it
would not cause a sensory loss at and below a dermatomal level. Therefore, imaging
of the head is not needed initially and likely would be helpful only if a demyelinating
spinal lesion is identified on MRI. Lumbar puncture is not indicated initially and could
cause problems for this child. Because the problem clearly localizes to the spine, it is
necessary to identify a structural problem in the spine first. If there is a mass lesion in
the spinal cord, shifting of the cord could cause more extensive problems.
Electroencephalography would not be helpful for this patient because the symptoms
and signs are not consistent with a seizure disorder.
•
An 8-year-old girl who has intellectual disability and
dysmorphic facial features presents to the emergency
department with reduced alertness of 24 hours' duration.
For the past hour, she has been crying inconsolably and
holding her head. At triage she makes poor eye contact
and is banging her head. Physical examination of the
irritable child reveals dysmorphic features and abnormal
head shape. On eye examination, her pupils are equally
reactive and appear normally aligned. It is unclear
whether her neck is supple, due to a lack of cooperation,
but she has a subcutaneous tube connected to a shunt
bulb over her right parietal skull.
Of the following, the MOST appropriate next step is to
1.
2.
3.
4.
5.
insert a needle into the shunt bulb
order brain MRI with contrast
order head CT without contrast
order stat electroencephalography
perform a lumbar puncture
•
•
Answer C
The girl described in the vignette is manifesting symptoms of elevated intracranial
pressure, including head pain and, ominously, mental status changes. The most likely
cause for her problems is a malfunction of her ventriculoperitoneal shunt, resulting in
acute hydrocephalus. The diagnostic modality of choice is head computed
tomography (CT) scan, which should be obtained emergently, along with a routine
radiographic shunt series to assess for disconnections in tubing.
Brain magnetic resonance imaging is less available than CT scan, requires more time
for study completion, and involves a greater need for sedation in an agitated patient.
Moreover, in this clinical setting, if there is hydrocephalus, it should be readily
apparent on CT scan.
Electroencephalography is not necessary emergently. Although nonconvulsive status
epilepticus could explain mental status changes, this condition typically would not
produce the pain syndrome this child is experiencing.
In the setting of elevated intracranial pressure, it is important to determine initially if
an intracranial mass lesion is present. Such a lesion may be a contraindication to the
use of lumbar puncture. Withdrawing fluid through the shunt generally is not
performed as an initial intervention before obtaining radiologic confirmation of the
shunt malfunction.
American Board of Pediatrics Content Specification(s): Recognize the signs and
symptoms of shunt malfunction in hydrocephalus
•
A 14-year-old girl has had 3 days of new,
unremitting headache associated with vomiting
and awakening from sleep and 1 day of double
vision. Physical examination reveals normal
visual acuity in each eye, normal pupillary
responses in each eye, subjective diplopia when
looking to the left, and incomplete abduction of
the left eye. Funduscopic examination reveals
bilateral papilledema (Item Q166). Noncontrast
head computed tomography scan yields normal
results.
Of the following, the MOST likely diagnosis is
1.
2.
3.
4.
5.
brain tumor in the posterior fossa
communicating hydrocephalus
complicated migraine
optic neuritis
pseudotumor cerebri
•
•
•
•
•
Answer E
The girl described in the vignette has a headache due to elevated intracranial
pressure. The most likely diagnoses when the history strongly supports elevated
intracranial pressure and the neurologic examination shows bilateral papilledema and
a 6th nerve palsy are either a space-occupying process such as a brain tumor or
hydrocephalus or pseudotumor cerebri. Normal findings on head computed
tomography scan generally exclude space-occupying processes sufficient to cause
such signs and symptoms, including hydrocephalus and a posterior fossa
(cerebellum, brainstem) tumor. Accordingly, the most likely diagnosis is pseudotumor
cerebri.
Complicated migraines are diagnoses of exclusion. Essentially, these are migraines
accompanied by strokelike symptoms that may present with visual complaints, but
more commonly they present with loss of strength on one side of the body or even
aphasia. They do not present with papilledema.
Optic neuritis, or inflammation of the optic nerve, typically is painful, especially with
eye movement; is unilateral; and causes loss of central visual acuity. The girl in the
vignette has normal visual acuity, which is often the case in pseudotumor. In optic
neuritis, papillitis, which can look like papilledema, may be seen
The first goal in assessing a new complaint of headache is to determine whether the
headache is due to an intracranial disease process, also known as a secondary
headache, or is a paroxysmal event related to an idiopathic headache disorder such
as migraine or tension headache, also known as a primary headache.
•
•
•
•
•
•
•
•
•
Because many secondary headaches produce pain related to elevations in
intracranial pressure, symptoms in the history that are consistent with this should be
elicited, including:
1. Pain worse when recumbent
2. Pain awakening from sleep or noted prominently on morning awakening
3. Pain resulting in vomiting, with subsequent temporary relief of pain
4. Pain worse with Valsalva maneuvers such as bowel movements or coughing
5. Pain unlike prior headache pains
6. Pain that has been unremitting/gradually increasing as opposed to typical waxing
and waning in chronic, nonprogressive primary headache disorders
The constellation of symptoms described for this girl raises these concerns and
should prompt a careful general and neurologic examination.
Two eye signs also should be sought carefully in the presence of a new headache.
The first is oculomotor paralysis. The subjective double vision looking laterally
indicates a new acquired ocular malalignment. This can localize to the brainstem, but
this patient has no other neighboring brainstem findings, such as facial weakness,
suggesting that the brainstem is not involved. In the setting of high intracranial
pressure headache, this can be a "false localizing sign"; that is, the brainstem is not
involved, although the finding does indicate brain pathology: raised intracranial
pressure. The second sign is the funduscopic examination finding of papilledema.
The funduscopic examination finding of blurred margins of the optic disc (ie,
papilledema) provides important confirmation of this clinical impression and warrants
urgent neuroimaging.
•
For this girl, head computed tomography (CT) scan should be performed in the
emergency department. Although head CT scan is less sensitive than magnetic
resonance imaging for some important intracranial lesions, including posterior fossa
tumors, it can exclude hydrocephalus or any posterior fossa lesions sufficiently large
to produce headache by inducing hydrocephalus. Head CT scan in pseudotumor
cerebri or idiopathic intracranial hypertension yields normal results. The diagnosis is
confirmed by lumbar puncture showing elevated pressure, greater than 20 cm, on
manometry.
•
When pseudotumor has been diagnosed, a thorough search should be undertaken
for the cause. Two common causes are obesity and use of oral acne medications
such as minocycline. Neurology referral is recommended. The major long-term risk is
permanent visual loss. At the time of presentation, subjective visual acuity may be
normal, as might be results of bedside testing. However, careful perimetry testing by
the ophthalmologist may show an enlarged blind spot. Left untreated, these may
enlarge further and become permanent.
•
•
•
American Board of Pediatrics Content Specification(s):
Know the importance of decreased vision in papilledema
Recognize the significance of papilledema
• A 22-month-old boy presents with irritability and
broad-based gait. In addition, he has mild tremor
of the trunk and jerky movements of his limbs,
particularly when excited or upset. His mother
noted some "funny" movements of his eyes
yesterday that she described as "bobbing."
Notable findings on neurologic examination
include irritability, poor cooperation, full
extraocular movements with no nystagmus,
normal face and tongue movements, general
tremulousness, jerky limb and trunk movements,
and broad-based, lurching gait. Brain magnetic
resonance imaging and cerebrospinal fluid
studies yield normal results.
Of the following, the test that is MOST likely to be useful in
establishing the diagnosis is
1.
2.
3.
4.
5.
alpha-fetoprotein measurement
electroencephalography
frataxin gene testing
serum ceruloplasmin & urinary copper levels
urinary vanillylmandelic acid & homovanillic
acid
•
•
Answer E
The diagnostic key for the boy described in the vignette is clinical recognition that he
has opsoclonus myoclonus ataxia syndrome. One possible cause is neuroblastoma,
a tumor that can trigger an autoimmune response, leading to the paraneoplastic
opsoclonus myoclonus syndrome. There is no characteristic antibody test for this
diagnosis, but the tumor may produce high quantities of catecholamines, which can
be identified in urine. Therefore, measurement of vanillylmandelic acid and
homovanillic acid in the urine is the most useful test for helping to establish the
diagnosis.
The symptoms of encephalopathy, with irritability and changes in motor control
affecting hands (tremor), gait, and balance, are ominous, and the differential
diagnosis is relatively broad. Anatomic localization of the gait problems and tremor
with behavioral change could be localized to the central nervous system above the
spinal cord, possibly the cerebellum and brainstem. The appropriate initial test, brain
magnetic resonance imaging, was obtained, and findings were normal/nondiagnostic.
Therefore, cerebrospinal fluid studies for infection/inflammation were appropriately
obtained.
The differential diagnosis of this clinical presentation includes two inflammatory
conditions: opsoclonus myoclonus ataxia syndrome and acute cerebellar ataxia.
These can be very difficult diagnoses to distinguish, particularly because opsoclonus
can be transient and clinicians may not recognize opsoclonus versus nystagmus.
Moreover, the multifocal and truncal myoclonus of opsoclonus myoclonus ataxia
syndrome visually resembles truncal ataxia of acute cerebellar ataxia. Urgent
neurology consultation is advisable.
•
Alpha-fetoprotein (AFP) is an important blood test to consider for a young child who
has chronic progressive choreoathetosis or ataxia. Elevated AFP values are present
in toddlers presenting with ataxia due to ataxia telangiectasia (AT), a condition in
which neurologic symptoms are present several years before telangiectasias emerge.
The extreme irritability exhibited by the child in the vignette is not characteristic of AT.
Moreover, the time course of his symptoms is subacute, over days, whereas AT and
other degenerative diseases typically progress over months or years.
Electroencephalography (EEG) provides information about the physiology of the
cerebral cortex that usually aids in epilepsy syndrome diagnosis and occasionally to
diagnose the cause of an encephalopathy or to help determine if myoclonus has a
cerebral cortical origin. It is unlikely to be helpful in this case because there are no
paroxysmal events under consideration, and EEG is not useful for diagnosing causes
of ataxic gait.
Frataxin gene testing is used to confirm the diagnosis of Friedreich ataxia, a
degenerative disease that presents after age 5 years with progressive gait ataxia,
distal sensory loss, and muscle wasting. Serum ceruloplasmin and urinary copper
testing are used in diagnosing Wilson disease. Neurologic manifestations of Wilson
disease, including dysarthria, dystonia, tremor, and mood disorder, do not present
until after the age of 5 years.
American Board of Pediatrics Content Specification(s): Understand that urinary
catecholamine excretion is increased in most patients with a neuroblastoma and that
tests of urine for VMA and VHA are appropriate screening tests for the tumor
A 15-year-old boy presents to the emergency
department after an apparent seizure. He had a
sudden arrest of normal activity at school, with
posturing on the left side, eye deviation, and loss
of consciousness for about 1 minute, followed by
confusion. On physical examination, he is fully
oriented and answers questions appropriately.
He is afebrile. Results of cranial nerve
examination, motor examination, and gait
evaluation are normal.
Of the following, the procedure that is MOST likely to
establish the cause of the seizure is
1.
2.
3.
4.
5.
brain MRI with contrast
electroencephalography
lumbar puncture
noncontrast head CT
urine toxicology screen
Answer: A
•
The boy described in the vignette has had a first unprovoked seizure. The semiology of the
seizure included some focality, with posturing on the left side, indicating that this was likely a focal,
or partial, seizure. In the emergency department, after resolution of the postictal confusion, his
mental status and neurologic examination results are normal.
The most important diagnostic test for determining the cause of one or more focal-onset seizures
is a brain magnetic resonance imaging (MRI) with contrast. Although head computed tomography
(CT) scan often is the initial neuroimaging performed in the emergency department, MRI is more
sensitive to lesions that can be missed on CT scan (Item C70). Rather than duplicating costly
neuroimaging studies, if the child is clinically healthy and the parents are reliable, the clinician
may safely defer an emergent head CT scan and schedule the more sensitive brain MRI as a
follow-up test.
Urine toxicology screening should be considered in the emergency department after a first
unprovoked seizure, but the lack of confusion or encephalopathy reported for the boy combined
with his rapid return to a normal mental status argues against a drug-induced seizure.
A lumbar puncture should be obtained in a child who has a partial seizure, fever, and confusion to
evaluate for encephalitides, particularly herpes encephalitis. Because this adolescent is afebrile
and has a clear sensorium, cerebrospinal fluid studies and urgent neuroimaging need not be
obtained.
Electroencephalography (EEG) can be helpful for determining an epilepsy syndrome diagnosis.
For example, juvenile myoclonic epilepsy can present at this age and is characterized by
myoclonus, generalized tonic-clonic seizures, and sometimes absence seizures, with generalized
epileptiform discharges on EEG. However, epilepsy is a clinical diagnosis made after two
unprovoked seizures. In the setting of a single focal seizure, the initial emphasis should be on
determining whether a treatable focal lesion caused the seizure, for which EEG is unlikely to be
helpful.
Item C70
•
Illustration of the enhanced diagnostic sensitivity of MRI scan compared with CT
scan. Noncontrast CT (left) and MRI (right) for the boy described in the vignette.
Although the CT scan shows no abnormality, MRI demonstrates a signal change in
the right cerebral hemisphere consistent with a low-grade glioma.