SLU NEUROBOWL 2001

1
SLU NEURO-BOWL 2001
edited by Kitti Kaiboriboon, M.D., Laurence J.
Kinsella, M.D. and John B. Selhorst,
M.D. Department of Neurology Saint Louis
University St. Louis, MO
2
SLU NEURO-BOWL 2001
The Neuro-Bowl is an educational exercise of the
Department of Neurology at Saint Louis
University. The program is modeled after the
Neuro-Bowl of the American Academy of Neurology.
One team of faculty members challenges another
team of faculty. One resident and a neurologist
from the clinical faculty also are members on
each team. Questions are prepared by the
remaining resident staff. Items are taken from
contemporary literature and often favor physical
signs, neuroimaging, diagnostic syndromes or
studies, definitive treatments and complications
of therapeutic efforts. Hopefully, the topics
chosen will prepare us better to care for the
patients we all serve.
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SLU NEURO-BOWL 2001
December 20, 2001
Kinsellas Synaptic Clefts
Laurence J. Kinsella Thomas J. Geller
L. James Willmore Enrique C. Leira
Tonya M. DiTrapani vs. Mithens Association
Neurons Francis A. Mithen
Ghazala R. Hayat Salvador Cruz-Flores
R. Edward Hogan Gisele R. Oliveira
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Question 1
What is the inheritance pattern of this
16-year-old boys muscular disease?
5
Answer 1
Autosomal Dominant
Facioscapulohumeral dystrophy derives its name
from the muscle groups that are primarily
afflicted. Initially facial muscles and the
shoulder girdle are involved, and later foot
extensors and pelvic-girdle muscles become
affected. The heart is not implicated in most
cases, though arrhythmias and conduction defects
have been described. Mental impairment is not a
feature, but retinal vascular disease and hearing
loss occur. This autosomal dominant disorder is
associated with subtelomeric deletion of
chromosome 4q, with loss of 3.3 kb tandem-repeat
units. Loss of ten or fewer repeats results in
the disorder, and in general, the lower the
number of repeats the more clinically severe the
condition. However the function of the particular
gene that causes this disorder is not clear.
(Emery AE. The muscular dystrophies. Lancet
2002359687-695)
6
Question 2
A 75-year-old man was admitted with the sudden
onset of a right homonymous hemianopia. He also
had anosmia for 11 years. Identify the cause of
his presentation on the CT scan.
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Answer 2
Left occipital infarction
CT scanning shows an ill-formed hypodensity in
the distribution of the left posterior cerebral
artery which corresponds to his hemianopia and is
likely the result of a left occipital infarct.
There is an incidental giant aneurysm with
curvilinear calcifications of the anterior
cerebral artery. Unruptured aneurysms of the
anterior cerebral artery most frequently cause
visual symptoms, endocrine disorders, headache,
dementia and emotional lability. This case is
unusual in that the only apparent symptom was
worsening hyposmia.
(Manconi M et al. Anosmia in a giant ACA
aneurysm. Arch Neuro 2001581474-1475)
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Question 3
A 21-month-old boy had normal growth and
development until six months of age when he began
to fail to thrive. Weight was less than three
percentile, but length, head circumference and
cognitive ability were appropriate for his age.
His condition represents what syndrome?
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Answer 3
Russells diencephalic syndrome
Russells diencephalic syndrome is manifested by
progressive emaciation and failure to thrive in
an apparently alert infant. It is usually
associated with a low-grade hypothalamic
astrocytoma. Figure A shows the severe
emaciation of the whole body and the
characteristic thin facies, sometimes called
"pseudohydrocephalic" appearance. Figure B,
T1-weighted sagittal images after gadolinium
enhancement, demonstrates the presence of a large
tumor involving the hypothalamic region,
distorting the chiasm and brain stem, and
extending into the third ventricle.
(Zafeiriou D et al. Russell's diencephalic
syndrome. Neurology 200157932)
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Question 4
A 70-year-old man with Parkinson's disease
underwent bilateral quadripolar electrode
placement in the subthalamic nucleus. Several
years later he required extraction of all of his
maxillary teeth because of periodontal disease
with osteonecrosis. The following day diathermy
treatments were given to hasten soft tissue
healing. After one hour of treatment he was
found completely unarousable. Vital signs were
normal. Pupils were small. All limbs withdrew
to pain. MRI of the brain was obtained three
days later. What is the cause of his
neurological condition?
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Answer 4
Radiofrequency burn of the basal ganglia and
upper brainstem due to diathermal stimulation of
deep brain electrodes
An MRI scan 3three days after the diathermy
treatments showed a bilateral, symmetrical T2
lesion in the tegmentum of the pons and midbrain,
cerebral peduncles and posterior limbs of the
internal capsule (Upper panel). An MRI was
repeated 32 days after the diathermy treatment
and demonstrated a reduction of the T2 signal to
the immediate proximity of the electrodes (Lower
panel). The time course of the acute
deterioration and the sequence of MRI changes
indicate that the neurological event was caused
by tissue damage around the subthalamic nucleus
electrodes induced by diathermy. The mechanism by
which diathermy interacted with the implanted
leads or electrodes is believed to be by
induction of an radiofrequency current and
heating of the electrodes. Whether this was
induction in the electrode wires through passage
in the soft tissues of the neck or directly upon
the DBS electrodes in the brain stem is uncertain.
(Nutt JG et al. DBS and diathermy interaction
induces severe CNS damage. Neurology
2001561384-1386)
12
Question 5
A 53-year-old man presented with a very slow
progression over ten years of a left T-10
Brown-Sequard syndrome. Spinal MRI showed that
the chronic myelopathy was due to what process?
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Answer 5
Spinal cord herniation through an anterior
dural defect
T1-weighted MRI (A) revealed forward protrusion
of the spinal cord at the T45 level. A CT
myelogram (B to D) revealed ventral displacement
of the spinal cord without a subarachnoidal cyst.
The spinal cord herniated through an anterior
dural defect often a pseudomeningocoele lies
anterior to the dura.
(Kawachi I et al. Spontaneous spinal cord
herniation. Neurology 200156977) (Marchman LA
et al. Idiopathic spinal cord herniation.
Neurosugery 1999 441129-33)
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Question 6
A 19-year-old man was hit on the back by a large
door. Two days later, he developed transient arm
dysesthesias and then severe back pain and leg
weakness progressing to quadriplegia. He died of
pulmonary embolism two weeks later. Autopsy
revealed what explanation for his acute
myelopathy?
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Answer 6
"Disc embolism" or nuclear pulposus emboli
Sections from the superior (A) and inferior
margins of the lesion showed acute ischemic
infarction. The embolic fibrocartilaginous
material, present in numerous sections of spinal
arteries and arterioles (B), is periodic
acidSchiff positive and diastase resistant, is
mucicarmine positive, and contains chondrocytes
in lacunae. Embolism of nucleus pulposus
material may involve retrograde venous transport
and arteriovenous shunts. Predisposing factors
are mild trauma or exercise. Premortem diagnosis
is facilitated by a sudden, painful onset and a
"stroke-in-evolution" pattern of progression.
(Freyaldenhoven T et al. Fibrocartilaginous
embolization. Neurology 2001561354)
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Question 7
A 62-year-old woman complained of headaches,
blurred vision and spontaneous phosphenes that
developed over a two-month period. She presented
because in the supine, but not upright position,
her head became grotesquely hyperemic. What is
the cause of this physical finding?
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Answer 7
Venous Sinus Thrombosis
Positional caput medusae occurred after a venous
sinus thrombosis. This phenomenon may be
explained by obstructed venous outflow along the
internal jugular vein, the predominant means of
cerebrovenous drainage in the supine position.
The venous angiogram (supine position) revealed
drainage of the superior sagittal sinus mainly
along the superficial middle cerebral vein
(arrow) and along the emissary veins through the
diploe. In the upright position the spinal
epidural veins may open as an additional drainage
pathway and improve cerebral venous drainage.
(Meyer B et al. Caput medusae after sinus venous
thrombosis. Neurology 2001571376)
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Question 8
An 89-year-old man presented with neck pain and
fever. Examination disclosed resistance to neck
flexion. Erythrocyte sedimentation rate was 97
mm/hour, and C-reactive protein was 8.4 mg/dl.
Spinal fluid analysis and brain CT were normal.
CT of neck showed periodontoid calcification
(black arrows). What treatment led to rapid
resolution of this man's illness?
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Answer 8
Indomethacin
CT scan of the cervical-occipital hinge. Thin
curvilinear, double-band, periodontoid
calcifications are detected in coronal and
sagittal views (black arrows). Degenerative
changes can be found at the articular surfaces
(gray arrows).
Calcium pyrophosphate dihydrate (CPPD)
arthropathy may involve any joint. Cervical
localization is related to several clinical
presentations meningeal syndromes, compressive
myelopathy, or an association of feverish acute
cervical pain and calcifications in the
periodontoid space, described as the Crowned
Dens Syndrome. After 50 mg of indomethacin,
there was a rapid resolution of this man's
Crowned Dens Syndrome and its associated CCPD
arthropathy.
(Mula M et al. Crowned dens syndrome. Neurology
200156275)
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Question 9
A 26-year-old woman presented with weakness of
the right hand and dysarthria. Spinal fluid
analysis disclosed a normal cell count and
protein, but oligoclonal bands. MRI showed
extensive high intensities in the left cerebral
hemisphere. What procedure established the
correct diagnosis?
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Answer 9
Brain biopsy revealed primary cerebral
amyloidoma
Isolated cerebral amyloidomas are rare. Sometimes
called primary CNS amyloidomas, they are a
localized form of amyloid deposition. Clinically
and radiographically, it is similar to a
slow-growing neoplasm. The radiographic findings
of CNS amyloidoma are typically patchy lesions
with intense enhancement following contrast
administration. The lesions have been
predominantly described as heterogeneous on
T2-weighted images and isointense to slightly
hyperintense on T1-weighted images. The
heterogeneous signal is felt to represent
nonuniform deposits of amyloid protein. The
correct diagnosis is unlikely to be made without
a brain biopsy.
Brain biopsy (B) reveals amyloid deposition in
the white matter surrounded by lymphocytes,
plasma cells, epithelioid cells and
multinucleated giant cells. Apple- green
birefringence of amyloid upon polarization, Congo
red stain. Immunohistochemical stain for lambda
light chains (C) shows high content of lambda
light chain expressing plasma cells (brown
reaction product), but no immunoreactivity of the
amyloid.
(Blattler T et al. Primary cerebral amyloidoma.
Neurology 200156777) (Symko SC et al. Imaging
of cerebral and brain stem amyloidomas. AJNR
2001221353-1356)
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Question 10
These two middle-aged women presented with mild
dementia, dysarthria, rigidity and postural
instability. A predominant "Procerus sign" gives
a gloomy appearance to the facies of both
patients. In what neurological disease does this
sign occur?
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Answer 10
Progressive supranuclear palsy (PSP)
PSP is characterized by vertical supranuclear
gaze palsy, axial rigidity, akinesia, dysarthria,
fronto-limbic dementia and postural instability.
A typical facial expression, described as
"astonished," "worried," or "reptile-like," has
been described. The expression may be due to a
focal dystonia of the procerus muscle as well as
to a combination of very reduced blinking, lid
retraction and gaze palsy. Procerus is a facial
muscle that originates in the nasal bone and
inserts in the skin in the center of the forehead
between the eyebrows it acts forming vertical
wrinkles in the glabella region and bridge of the
nose. Both patients show this typical sign,
occurring without concomitant blepharospasm. The
wrinkling is present with open and closed eyes.
This sign could be called "the procerus sign."
(Romano S et al. Procerus sign in PSP. Neurology
2001571928)
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Question 11
A 36-year-old man presented with diplopia and
paresthesias. The high intensities in the MR
scan indicated by the open arrows are caused by
what underlying histopathological changes?
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Answer 11
Perivenular inflammation
These are areas of perivenular inflammation that
occur in multiple sclerosis. More than 85 of MS
patients have ovoid periventricular lesions that
are oriented perpendicularly to the long axis of
the brain and lateral ventricles. This
correlates well
with the histological localization of
demyelination around subependymal and deep white
matter medullary veins. The callososeptal
interface is a typical location. The
periventricular extension into the centrum
semiovale, sometimes called Dawson's fingers.
(Osborn A, ed. Diagnositic Neuroradiology
1994757)
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Question 12
What is the name of this structure indicated by
the arrows on the brain MRI scan of this
45-year-old man?
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Answer 12
Virchow-Robin's spaces
These are prominent vascular spaces or
Virchow-Robin's spaces (VRS) which are shown in
this autopsy specimen. Small VRSs are found in
patients of all ages and are a normal anatomical
variant. VRSs increase in size and frequency with
advancing age. Other factors such as
hypertension, dementia and incidental
white-matter lesions are also associated with
large VRSs, but are considered part of the aging
process and are not independent variables.
(Osborn A, ed. Diagnositic Neuroradiology
1994750-752)
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Question 13
A 57-year-old man presented with diplopia. This
progressed to complete ophthalmoplegia, facial
weakness and ataxia. Examination disclosed
hyporeflexia, too. A brain MRI with gadolinium
was obtained. What do the two arrows indicate?
29
Answer 13
Contrast enhancement of the oculomotor and
abducens nerves in a patient with Miller Fisher
Syndrome (MFS).
MFS is thought to be a clinical subtype of the
GuillianBarré syndrome and is characterized by
the neurological signs of ophthalmoplegia, gait
ataxia and areflexia. Facial paresis also
frequently occurs in MFS. Axial sections of brain
MRI after double-dose gadolinium administration
T1-weighted and fat-suppressed technique
demonstrates enhancement of 3rd (A), 6th (B), and
7th (not shown) cranial nerves bilaterally. MRI
of the brain with a double dose of gadolinium may
be a good confirmatory test for a diagnosis of
MFS in the correct clinical setting.
(Garcia-Rivera CA et al. Miller Fisher Syndrome.
Neurology 2001571755)
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Question 14
A 35-year-old man who sprayed pesticides in a
poorly ventilated basement developed a metallic
taste and a garlic-like odor to his breath.
Later that day, he developed drowsiness and
headache. His condition deteriorated to stupor
and profound hypotension. With supportive care,
he recovered, but has a residual distal
sensorimotor neuropathy. What is the cause of
his condition?
31
Answer 14
Arsenic poisoning Signs and symptoms of arsenic
intoxication include nausea, vomiting, colicky
abdominal pain and profuse, watery diarrhea.
Hypotension, fluid and electrolyte disturbances,
mental status changes, electrocardiographic
abnormalities, respiratory failure and death can
result. Quantitative measurement of 24-hour
urinary arsenic excretion is the only reliable
laboratory test to confirm arsenic poisoning.
Treatment includes gastric emesis or lavage,
chelation therapy, electrolyte and fluid
replacement, and cardiorespiratory
support. Arsenic-induced polyneuropathy is
traditionally classified as an axonal-loss type,
electrodiagnostically resulting in low amplitude
or absent sensory and motor responses, relatively
preserved proximal and distal motor conduction
rates, and distal denervation. Acute arsenic
toxicity must be suspected in patients with
clinical and electrodiagnostic features
supporting the Guillain-Barre syndrome.
(Donofrio PD et al. Acute arsenic intoxication as
GBS-like. Muscle Nerve 198710114-120)
32
Question 15
Some families have children with seizures
occurring only at birth. The genetic mutation
responsible for benign familial neonatal
convulsion results in a defect in what component
of the neuron?
33
Answer 15
Potassium channels Epilepsy affects gt0.5 of
the world's population and has a large genetic
component. The most common human genetic
epilepsies display a complex pattern of
inheritance, and the identity of the
susceptibility genes is largely unknown.
Mutations in KCNQ2 or KCNQ3 cause benign familial
neonatal convulsions (BFNC), a rare
autosomal-dominant generalized epilepsy of
newborns, by reducing the maximal current carried
by the M-channels without affecting ion
selectivity or gating properties.
(Berkovic SF et al. Genetics of the epilepsies.
Curr Opin Neurol 1999177-182)
34
Question 16
Name one of the two types of autosomal dominant
ataxias that feature downbeat nystagmus.
35
Answer 16
Spinocerebellar Atrophy type 6 or Episodic
Ataxia type 2 Spinocerebellar ataxia type 6
(SCA6) was identified as a form of autosomal
dominant cerebellar ataxia associated with small
expansions of the trinucleotide repeat (CAG)n in
the gene CACNL1A4 on chromosome 19p13. This gene
encodes the alpha1 subunit of a P/Q-type
voltage-gated calcium channel. Clinical and
quantitative measurement of extraocular movements
demonstrated a characteristic pattern of ocular
motor and vestibular abnormalities, including
horizontal and vertical nystagmus and an abnormal
vestibulo-ocular reflex. The SCA6 mutation is
allelic with episodic ataxia type 2 (EA-2), but
the two differ clinically because of the presence
of progressive, rather than episodic, ataxia in
SCA6.
(Gomez CM et al. Spinocerebellar ataxia type 6
gaze-evoked and vertical nystagmus, Purkinje cell
degeneration, and variable age of onset. Ann
Neurol 199742933-950)
36
Question 17
Name an ancillary diagnostic study that would
indicate the cause of the six-month dementia
occurring in the patient with this MR scan?
37
Answer 17
CSF analysis for 14-3-3 protein
CSF analysis for 14-3-3 protein occurs in 96
patients with Creuzfeldt-Jacob disease (CJD). The
protein is not specific for CJD because it occurs
in patients with herpes simplex encephalitis and
acute cerebral infarction. However, in the
appropriate setting the finding of the 14-3-3
protein in the spinal fluid is highly supportive
of CJD. Findings in MRI have been reported in
several cases of pathologically established CJD.
Brain MRI might be normal or show either brain
atrophy or symmetric, hyperintense signals of the
basal ganglia in T2 weighted images as shown
above.
(Hsich G et al. The 14-3-3 as a marker for CJD. N
Eng Med 1996335924-930)
38
Question 18
What is the recommended treatment for this
24-year-old man who has seizures and this MR scan?
39
Answer 18
Albendazole or Praziquantel
Taenia solium neurocysticercosis is a common
cause of epileptic seizures and other
neurological morbidity in most developing
countries. It is also an increasingly common
diagnosis in industrialized countries because of
immigration from areas where it is endemic. Its
clinical manifestations are highly variable and
depend upon the number, stage and size of the
lesions as well as the host's immune response.
Multiple cystic lesions, some with calcium, edema
and contrast-enhancement are characteristic of
cysticercosis. Treatment of choice is
albendazole or, if allergic, praziquantel.
(Del Brutto OH et al. Therapy for
neurocysticercosis. Clin Infect Dis
199317730-735)
40
Question 19
What is the case of this pathological finding?
41
Answer 19
Rabies
These are intracytoplasmic inclusions or Negri
bodies that are pathognomonic of rabies. Negri
bodies are well-defined, often oval or elongated,
eosinophilic cytoplasmic inclusions in neurons,
which represent accumulations of viral particles.
Negri bodies are most common in cerebellar
Purkinje cells, hippocampal pyramidal cells and
neocortical neurons. Smaller, less well-defined
inclusion bodies, previously termed "lyssa
bodies," are often more numerous than Negri
bodies and also represent accumulations of virus.
These findings are therefore as pathognomonic as
Negri bodies.
(Basgoz N et al. Case 21-1998. N Eng Med
1998339105-112)
42
Question 20
This is the MR scan of a 24-year-old woman who
had measles encephalitis at five years of age and
a subsequent poorly controlled seizure disorder.
Examination was normal except for hyperactive
tendon reflexes on the right. The MR scan is
illustrative of what unique process?
43
Answer 20
Transynaptic retrograde degeneration
The MR scan shows crossed cerebellar atrophy. In
a 1985 article in Brain, Dr. HD Chung described
four patients in which unilateral cerebral
atrophy was associated with contralateral
cerebellar atrophy. He proposed that this
occurred due to transynaptic retrograde
degeneration of frontal and thalamic pathways.
(Chung HD. Retrograde crossed cerebellar atrophy.
Brain 1985108881-895)
44
Question 21
A 35-year-old man developed a right lateral
medullary syndrome while aiming his arrow on his
inaugural bow hunt. What dynamic activity during
angiography was required to demonstrate the cause
of his "Bow Hunter's stroke?"
45
Answer 21
Twenty-degree head turn
Anatomically, the vertebral artery courses
through six foramina transversaria of the
cervical vertebrae, passing through the groove on
the surface of the arch of the atlas and then
penetrating the dura mater. Bow hunter's stroke
is a consequence of vertebrobasilar insufficiency
as a result of mechanical occlusion or stenosis
of the vertebral artery at the C1-C2 level by
head rotation. In most cases, a dominant
vertebral artery is involved. Twenty-degree head
turning during vertebral angiography is the
dynamic maneuver required to clearly show the
vertebral artery occlusion occurring with
alantoaxial rotation.
(Matsuyama T et al. Bow Hunters stroke.
Neurosurgery 1997411393-1395)
46
Question 22
These skin lesions appeared over the buttocks in
a young man who complained of intermittent
burning and numbness of the fingers and toes.
What is the diagnosis of his complaints and the
findings that led to a favorable treatment?
47
Answer 22
Fabrys disease
Fabrys disease is an X-linked recessive disorder
caused by a deficiency of alpha-galactosidease A
and storage of globotriaoxylceramide in lysosomes
of blood vessels and nerves. This pathological
deposition results in characteristic skin
lesions, neuropathy, renal failure and stroke.
Men are predominantly affected, but many female
carriers have similar clinical involvement,
including increased risk of stroke. Physical
stigmata, such as angiokeratomas in skin and
mucous membranes and characteristic benign
corneal abnormalities, facilitate identification
of Fabrys disease. The finding of a marked
decreased activity of alpha-galactosidase A in
white blood cells or cultured skin fibroblasts
confirms the diagnosis. Treatment thus far has
been symptomatic only. Recently intravenous
infusions of alpha-galactosidase A in patients
with Fabrys disease demonstrates the safety and
efficacy of this treatment.
(Brady RO et al. Clinical features of and recent
advances in Fabry disease. JAMA
20022842772-2775)
48
Question 23
Number 1 in the diagram depicts Wernicke's area
in the left temporal lobe. A lesion in number 5
results in what specific neurological deficit?
49
Answer 23
Callosal apraxia
A callosal apraxia occurs with lesions of the
anterior corpus callosum. This is demonstrated
by the ability to perform purposeful movements of
the right hand and the inability to perform them
in a dexterous and strong left hand.
(Brazis PW, Masdeu JC, Biller J, eds.
Localization in Clinical Neurology 2001504)
50
Question 24

• In the care of debilitated patients, it is
  important to realize that muscle protein turnover
  occurs at the following rate
•  
• 50 in 14 days
• 100 in 14 days
• 50 in one month
• 100 in one month
• 50 in 90 days

51
Answer 24
(B) 100 in 14 days
Although skeletal muscle has a primary function
of providing locomotion, it is a major depository
of protein and free amino acids that are used for
gluconeogenesis, wound healing and synthesis of
antibodies and acute phase proteins
during catabolic diseases. Loss of lean body mass
is associated with loss of strength and immune
function with an increased disability and
mortality. Muscle protein turnover, the balance
between protein synthesis and protein
breakdown, is affected by various physiological
states such as fasting, feeding, disease and
aging resulting in a net increase or decrease in
protein deposition. In the care of debilitated
patients, it is important to realize that muscle
protein turnover occurs at 100 in 14 days (B)
52
Question 25
CANOMAD is a recently described disorder the
includes Chronic Ataxic Neuropathy,
Ophthalmoplegia, M-protein, Agglutination and
Disialsoyl antibodies. The condition resembles a
"chronic Miller Fisher syndrome." The IgM
protein is an antibody directed to disialyated
gangliosides. Interestingly, what other antibody
is frequently elevated in CANOMAD?
53
Answer 25
GQ1b Antibody The clinical picture of CANOMAD
consists of a chronic neuropathy with marked
sensory ataxia and areflexia with relatively
preserved motor function in the limbs. In
addition, motor weakness affecting oculomotor and
bulbar muscles as fixed or as relapsing-remitting
features are observed. This distribution of
clinical features is reminiscent of Miller Fisher
syndrome, in which acute-phase anti-disialylated
ganglioside IgG antibodies are found. Clinical
electrophysiology and nerve biopsy show both
demyelinating and axonal features. A partial
response to intravenous immunoglobulin and other
treatments is reported in some cases.
(Willison HG et al. The clinical and laboratory
features of chronic sensory ataxic neuropathy
with anti-disialosyl IgM antibodies. Brain
20011241968-1977)
54
Question 26
In women with menstrual migraine, the time of
highest risk of headache is   A. First two
days of menses B. Last two days of
menses C. During the entire menstrual
period D. Time of ovulation
55
Answer 26
(A) The first two days of menses
The term "menstrual migraine" (MM) refers to
migraine attacks that occur perimenstrually,
although precise definitions vary. The
International Headache Society suggests that
migraine without aura is the predominant variant
associated with the menstrual
cycle and requires that 90 of attacks should
occur between two days before menses and the last
day of menses. The population base study
demonstrated that attacks of migraine without
aura, but not migraine with aura, were more
likely to occur two days before onset of menses
and on the first two days of menses.
(Stewart WF et al. Menstrual cycle and headache
in a population sample of migraineurs. Neurology
2000551517-1523)
56
Question 27
A 32-year-old, former equipment operator avulsed
a cervical root when his crane tipped over. He
presented 10 years later because of an
insidiously progressive gait ataxia. Examination
was remarkable for bilateral deafness,
generalized hyper-reflexia, extensor plantar
signs and a wide-based gait. MR scanning was
additionally remarkable. What is his diagnosis?
57
Answer 27
Superficial siderosis (SS) of the CNS
The triad of progressive bilateral deafness,
cerebellar ataxia and myelopathy allow a bedside
diagnosis of SS. MR scanning shows a distinctive
black rim of characteristic hypointensities
overlying the vermis and adjacent cerebellum,
brain stem, basal cisterns, spinal cord and
eighth nerve on T-2 images. The usual sources of
subarachnoid bleeding in SS are dural
abnormalities, vascular lesions and tumors. Dural
abnormalities including CSF-containing cavities
(meningoceles and arachnoid cysts and
posthemispherectomy), cervical nerve root lesions
(avulsions and epidural cysts), and chronic
subdural hematomas account for
almost half of the patients with an identifiable
source of bleeding. Vascular lesions associated
with SS include arteriovenous malformations,
unruptured aneurysms and cavernous angiomas. SS
also can be caused by chronic bleeding from a
brain or spinal cord tumormost commonly an
ependymoma. In some patients a source of
subarachnoid bleeding is not found.
(Fishman RA. Superficial siderosis. Ann Neurol
199334635-636)
58
Question 28
With the advent of HAART (highly active
antiretroviral treatment) being prescribed for
AIDS patients, what common focal brain lesion has
declined?
59
Answer 28
Primary CNS lymphoma
During the HAART era, AIDS-related primary CNS
lymphoma (PCNSL) showed a strong decline,
toxoplasmic encephalitis remained stable, and
progressive multifocal leukoencephalopathy showed
a slight increase. Focal white matter lesions
without mass effect or contrast enhancement
became the most frequently seen focal brain
lesion. These observations were consistent with
the fact that PCNSL is a manifestation of the
advanced immunosuppression phase of AIDS, and its
onset may be influenced by the immune
reconstitution observed with HAART. In contrast,
systemic non-Hodgkins lymphoma, which relates
differently to immunosuppression, did not seem to
decline during the HAART era. The hypothesis that
the reduced occurrence of PCNSL is directly
related to the effect of HAART on immune recovery
was further supported by the beneficial effect of
antiretroviral and immune therapy on prognosis in
AIDS-related PCNSL.

(Ammassari A et al. AIDS-related focal brain
lesions in the era of highly active
antiretroviral therapy. Neurology
2000551194-1200)
60
Question 29
A 48-year-old man ingested an unknown chemical
compound. Several hours later he was found
comatose. CT and a latter MR scan implicated
what intoxicant?
61
Answer 29
Methanol
Non-enhanced CT brain showed low attenuation,
primarily in the subcortical white matter of both
cerebral hemispheres, as well as abnormal
hypodensity of the putamen. Additional focus of
hemorrhage involved the right putamen (A). MRI
flair sequence demonstrated an increased signal,
especially in the subcortical white matter of
both cerebral hemispheres. The brighter signal
involving the putamen represents edema, as well
as coexistent blood products on the right (B).
This was consistent with primarily subcortical
white matter infarction and bilateral putamenal
necrosis with right-sided hemorrhage, documented
on postmortem examination (C). The presence of
subcortical white matter (with relative sparing
of centrum semiovale) and putamenal injury are
typical of severe methanol toxicity. This is
likely related to methanol metabolism to
formates, hypoxemia, severe acidosis and
coexistent circulatory depression.
(Feris CS et al. Severe brain injury in methanol
ingestion. Neurology 2000541239)
62
Question 30
What is the most common pathogen responsible for
brain abscess?
63
Answer 30
Anaerobic and microaerophilic streptococi
A brain abscess consists of localized free or
encapsulated pus within the brain substance.
Predisposing conditions are always present.
Pyogenic organisms gain access to the brain
substance by one of three routes. The first is
through the blood stream either from a remote
infection or in association with a
cardiopulmonary malfunction, most commonly
cyanotic congenital heart disease with a
right-to-left shunt. The second is by extension
of contiguous infections such as leptomeningitis,
infections of the middle ear or infections of the
paranasal sinuses, either directly or a result of
septic thrombophelebitis of bridging veins. The
third is a complication of a penetrating wound.
The most common causative organisms in order of
frequency are anaerobic and microaerophilic
streptococi (60-70), Fusobacterium species,
Beta-hemolytic streptococci, S. aureus and
pneumococci. Anaerobic organisms alone cause
approximately 56 of brain abscesses, aerobic
bacteria 18, and mixed aerobic and anaerobic
bacteria 26. Treatment should include a diligent
search for the source of infection. Initial
therapy should include coverage for anaerobic as
well as aerobic organisms. The antibiotics of
choice are generally IV penicillin G,
chloramphenicol or metronidazole. Oxacillin or
methicillin also should be started until it is
established that a Beta-lactamase-producing
organism is not involved. It is continued for a
minimum of three weeks, and often for 4-6 weeks.
Sugical therapy is indicated when the patient
does not improve after 24 hours of antibiotic
therapy, when clinical status deteriorates, or
when there is life-threatening displacement of
cerebral structures. Sinusitis or mastoiditis
contiguous to a brain abscess should be treated
vigorously, usually with prompt surgery. A short
couse of corticosteroids to reduce
life-threatening edema can be used safely.
(Weil ML et al. Infections of the nervous system.
Menkes JH, Sarnat HB, eds. Child Neurology, 6th
ed 467-626)
64
Question 31
A healthy 52-year-old woman began to decline
intellectually. She made mistakes in her job as
a bookkeeper and had difficulty taking phone
messages. She also began to stumble with
occasional falls and became depressed. MR scan
of the brain revealed a convexity meningioma that
was successfully removed. She did not, however,
improve. Why?
65
Answer 31
MRI shows markedly shrunken caudate nucleus, the
pathognomonic sign for Huntingtons disease.
Genetic analysis of this patient showed 44 CAG
repeats that established a diagnosis of HD.
Chorea can be absent in the early stages of the
dementia. Abnormalities are limited to the brain.
The caudate nucleus, particularly its
paraventricular portion, is the most affected.
Cell death within the striatum does not affect
all neurons equally. The medium-sized GABA-ergic
spiny projection neurons are the first to be
affected. The mechanism for this selective
vulnerability is still unclear. The gene for HD
is mapped to the telomere (tip) of the short arm
of chromosome 4.
(Reich SG. Neurovignette. The Neurologist
20017308)