Nutritional and Metabolic Disorders

Question 1

191. In Tay-Sachs disease, the enzymatic abnormality responsible for the
neurologic deficits is deficiency of
a. Hexosaminidase A
b. Glucocerebrosidase
c. Phosphofructokinase
d. Glucose phosphorylase
e. Sphingomyelinase

Answer 1

a. Hexosaminidase A

Question 2

192. With β-glucosidase deficiency, the affected child is likely to exhibit
     abnormal accumulations of which of the following?
     a. Glucosylceramide
     b. Gganglioside
     c. Galactosyl sulfatides
     d. Sphingomyelin
     e. Trihexosylceramide

Answer 2

a. Glucosylceramide

Question 3

Items 193–194
193. A 53-year-old left-handed man presents with asterixis, esophageal
varices, splenomegaly, and abdominal ascites. He is likely to exhibit altered
consciousness on the basis of which of the following?
a. Renal tubular acidosis
b. Impaired hepatic detoxification of portal blood
c. Splenomegaly-induced anemia
d. Copper intoxication
e. Vitamin B12deficiency

Answer 3

b. Impaired hepatic detoxification of portal blood

Question 4

194. This patient survives with his disorder for 2 years. At the time of
     death, he would be expected to exhibit changes in which type of brain cells?
     a. Oligodendrocytes
     b. Striatal neurons
     c. Pigmented cells of the substantia nigra
     d. Astrocytes
     e. Inferior olivary neurons

Answer 4

d. Astrocytes

Question 5

195. The cerebrospinal fluid (CSF) protein content with either uremic
     encephalopathy or hypertensive encephalopathy is likely to be
     a. Abnormally low
     b. Normal
     c. Elevated to less than 100 mg /dL
     d. Elevated to between 500 and 1000 mg /dL
     e. Greater than 2000 mg /dL

Answer 5

c. Elevated to less than 100 mg /dL

Question 6

Items 196–198
A 65-year-old man has had many years of deteriorating kidney func-
tion due to diabetes. At age 59, dialysis was begun because of electrolyte
abnormalities.
196. The most common neurologic complication of chronic renal failure is
a. Peripheral neuropathy
b. Delirium
c. Seizures
d. Dementia
e. Labile affect

Answer 6

a. Peripheral neuropathy

Question 7

197. As the patient becomes uremic, he tends to develop the restless legs
     syndrome. This may be controlled with
     a. Haloperidol
     b. Clonazepam
     c. Caffeine
     d. Nifedipine
     e. Rifampin

Answer 7

e. Rifampin

Question 8

198. The most reliable treatment for the peripheral neuropathy of chronic
renal failure is
a. Thiamine supplements
b. Clonazepam
c. Phenytoin
d. Minoxidil
e. Renal transplant

Answer 8

b. Clonazepam

Question 9

Items 199–202
A 68-year-old man presents with acroparesthesia, sensory ataxia, mem-
ory loss, and impotence. On exam, there are upper motor neuron signs in all
four extremities. He also has anemia and a sore tongue. Eventually vitaminB12 deficiency is diagnosed.
199. For vitamin B12 to be absorbed, it must bind to
a. A cyanide atom and form cyanocobalamin
b. An intrinsic factor
c. The parietal cells of the stomach
d. The ileal mucosa
e. The jejunal mucosa

Answer 9

b. An intrinsic factor

Question 10

200. With vitamin B
deficiency, which of the following accumulates in
the blood?
a. Cysteine
b. Methylmalonic acid
c. Methionine
d. Succinic acid
e. Propionic acid

Answer 10

e. Propionic acid

Question 11

201. The patient with impaired vitamin B
absorption is likely to develop
a positive Romberg test because of damage to which of the following?
a. Cerebellar vermis
b. Cerebellar hemispheres
c. Spinal cord lateral columns
d. Basal ganglia
e. Spinal cord posterior columns

Answer 11

e. Spinal cord posterior columns

Question 12

202. The type of visual field cut most often seen with vitamin B
deficiency
is a
a. Centrocecal scotoma
b. Homonymous hemianopsia
c. Bitemporal hemianopsia
d. Binasal hemianopsia
e. Hemianopsia with central sparing

Answer 12

a. Centrocecal scotoma

Question 13

203. A 42-year-old woman is being treated with methotrexate for Wegener’s
     granulomatosis. She is at risk for megaloblastic anemia and peripheral neuropathy
     because methotrexate
     disturbs the metabolism of
     a. Cobalamin
     b. Iron
     c. Copper
     d. Pyridoxine
     e. Folate

Answer 13

e. Folate

Question 14

Items 204–206
A 37-year-old woman develops cholecystitis and requires cholecystec-
tomy. Her family advises the physicians involved that she has a long history
of alcoholism and benzodiazepine use, including diazepam (Valium),
lorazepam (Ativan), and clonazepam (Klonopin). Approximately 7 days
after the surgery, the patient becomes increasingly agitated, delusional, and
suspicious. Routine investigations reveal no evidence of focal or systemic
infection. Hepatic, renal, and hematologic parameters are largely normal.
Within 24 h of these cognitive and affective changes, the patient has a generalized
tonic-clonic seizure.Magnetic resonance
imaging (MRI) and computed tomography
(CT) studies of the brain are normal, and her CSF is unremarkable.
204. In consideration of the abuse history provided by the family, medication orders prior to the surgery should have included
a. Haloperidol
b. Chlorpromazine
c. Trihexyphenidyl
d. Prochlorperazine
e. Thiamine

Answer 14

e. Thiamine

Question 15

205. The patient’s neurologic deterioration was most probably caused by
     a. A delayed anesthetic reaction
     b. Benzodiazepine withdrawal
     c. Alcohol withdrawal
     d. Unreported cocaine use
     e. Idiopathic epilepsy

Answer 15

b. Benzodiazepine withdrawal

Question 16

206. In anticipation of the seizures and cognitive deterioration that might
     occur postoperatively, the physician involved would have been wise to
     a. Consult a psychiatrist and neurologist prior to surgery
     b. Provide intravenous alcohol supplements postoperatively to blunt the alcohol withdrawal
     c. Provide intramuscular or oral chlordiazepoxide several times daily at a dose dictated by the patient’s level of agitation
     d. Start phenytoin as a single dose nightly
     e. Delay surgery until the risk of neurologic problems abated

Answer 16

c. Provide intramuscular or oral chlordiazepoxide several times daily at a dose
dictated by the patient’s level of agitation

Question 17

DIRECTIONS: Each group of questions below consists of lettered options
followed by a set of numbered items.
For each numbered item, select the one
lettered option with which it is most closely associated. Each lettered option may be used once, more than once, or not at all.
Items 207–213
For each clinical scenario, select the nutritional deficiency that is most
likely responsible.
a. Deficiency amblyopia
b. Vitamin B deficiency
c. Pyridoxine (vitamin B12) deficiency
d. α tocopherol (vitamin E) deficiency
e. Vitamin D deficiency
f. Thiamine (vitamin B1) deficiency
g. Nicotinic acid deficiency
h. Kwashiorkor
i. Vitamin C deficiency
207. A 26-year-old man develops hemoptysis and dyspnea over the
course of 3 months. His physician suspects tuberculosis and starts him on
triple therapy with isoniazid (isonicotinic acid hydrazide), rifampin, and
ethambutol. After 1 month of treatment, the patient’s liver enzymes show
slight elevations, but the treatment is continued. The hemoptysis stops by
2 months, but the patient complains of pins-and-needles sensations in his
feet. Neurologic examination reveals hypoactive deep tendon reflexes in
the legs and slightly impaired position sense. Strength is good in all limbs.

Answer 17

c. Pyridoxine (vitamin B12) deficiency

Question 18

208. A 50-year-old woman is found wandering in the street and is brought
     to the emergency room by the police. She is disoriented to time, place, and
     person, but has no evidence of head trauma. She staggers when she tries to
     walk, but she has no detectable alcohol in her blood. Eye movements are
     abnormal with paresis of conjugate gaze, and horizontal nystagmus is
     apparent. Relatives are contacted, and they report that this woman has a
     long history of alcohol abuse. (SELECT 1 DEFICIENCY)
     a. Deficiency amblyopia
     b. Vitamin B deficiency
     c. Pyridoxine (vitamin B12) deficiency
     d. α tocopherol (vitamin E) deficiency
     e. Vitamin D deficiency
     f. Thiamine (vitamin B1) deficiency
     g. Nicotinic acid deficiency
     h. Kwashiorkor
     i. Vitamin C deficiency

Answer 18

f. Thiamine (vitamin B1) deficiency

Question 19

209. A 46-year-old man complains of progressive visual problems. He
     notices problems with discriminating objects both up close and far away.
     His deficits have progressed over the course of 3 months. He has a 12-year
     history of pipe smoking, a 14-year history of daily aspirin use, and a 20year history of alcohol intake. He usually drinks 4oz of gin daily. Examination reveals enlargement
     of the physiologic blind spot to the point where it extends into central vision. (SELECT
     1 DEFICIENCY)
     a. Deficiency amblyopia
     b. Vitamin B deficiency
     c. Pyridoxine (vitamin B12) deficiency
     d. α tocopherol (vitamin E) deficiency
     e. Vitamin D deficiency
     f. Thiamine (vitamin B1) deficiency
     g. Nicotinic acid deficiency
     h. Kwashiorkor
     i. Vitamin C deficiency

Answer 19

g. Nicotinic acid deficiency

Question 20

210. A 32-year-old South African woman develops irritability, sleeplessness,
and fatigue. Her family believes that she is depressed, but neurologic assessment establishes prominent short- and long-term memory problems.
She has anemia and an obvious dermatitis on her face. Her diet is strictly vegetarian and limited almost entirely to grains, such as corn. (SELECT 1 DEFICIENCY)
a. Deficiency amblyopia
b. Vitamin B deficiency
c. Pyridoxine (vitamin B12) deficiency
d. α tocopherol (vitamin E) deficiency
e. Vitamin D deficiency
f. Thiamine (vitamin B1) deficiency
g. Nicotinic acid deficiency
h. Kwashiorkor
i. Vitamin C deficiency

Answer 20

a. Deficiency amblyopia

Question 21

211. A 61-year-old man develops progressive cramping of his legs and a
     pins-and-needles sensation in his feet over the course of 1 year. He consults
     a physician when he notices paresthesias in his hands and unsteadiness of
     his gait. His family reports that he has had some urinary incontinence, but
     was too embarrassed to report it. On examination, he has a spastic paraparesis
     with severe disturbance of position and vibration sense in his legs.
     Despite obvious spasticity in the legs, the deep tendon reflexes are absent atthe knees and ankles. Peripheral blood smear reveals hypersegmented
     polymorphonuclear leukocytes. (SELECT 1 DEFICIENCY)
     a. Deficiency amblyopia
     b. Vitamin B deficiency
     c. Pyridoxine (vitamin B12) deficiency
     d. α tocopherol (vitamin E) deficiency
     e. Vitamin D deficiency
     f. Thiamine (vitamin B1) deficiency
     g. Nicotinic acid deficiency
     h. Kwashiorkor
     i. Vitamin C deficiency

Answer 21

b. Vitamin B deficiency

Question 22

212. A 4-year-old boy develops progressive gait ataxia and limb weakness
     over the course of 3 months. Neurologic assessment reveals diffusely absent
     deep tendon reflexes, proximal muscle weakness, ophthalmoparesis, and
     poor pain perception in the feet. Blood tests reveal elevated creatine phosphokinase
     (CK) levels and abnormally high serum bilirubin levels.
     Further investigations of hepatic function reveal that the child has a cholestatic hepatobiliary disorder, but there is no evidence of hepatic dysfunction sufficient to cause an encephalopathy.
     (SELECT 1 DEFICIENCY)
     a. Deficiency amblyopia
     b. Vitamin B deficiency
     c. Pyridoxine (vitamin B12) deficiency
     d. α tocopherol (vitamin E) deficiency
     e. Vitamin D deficiency
     f. Thiamine (vitamin B1) deficiency
     g. Nicotinic acid deficiency
     h. Kwashiorkor
     i. Vitamin C deficiency

Answer 22

d. α tocopherol (vitamin E) deficiency

Question 23

213. A 9-month-old girl from famine-stricken Ethiopia exhibits profound
     apathy and indifference to her environment. She is afebrile and appears to
     have no significant infections at the time of her initial evaluation. Her hair
     is sparse, and slight edema is evident about her ankles. She is well below
     the fifth percentile for height in her age group. With handling she becomes
     irritable, but throughout her examination she exhibits little spontaneous
     movement. Her mother reports having seen transient tremors in the girl’s
     hands a few weeks earlier, but these abated after a few days. (SELECT 1
     DEFICIENCY)
     a. Deficiency amblyopia
     b. Vitamin B deficiency
     c. Pyridoxine (vitamin B12) deficiency
     d. α tocopherol (vitamin E) deficiency
     e. Vitamin D deficiency
     f. Thiamine (vitamin B1) deficiency
     g. Nicotinic acid deficiency
     h. Kwashiorkor
     i. Vitamin C deficiency

Answer 23

h. Kwashiorkor

Question 24

Items 214–220
For each clinical scenario, select the most likely diagnosis.
a. Postictal state
b. Hypothyroidism
c. Uremic encephalopathy
d. Wernicke’s encephalopathy
e. Herpes encephalitis
f. Progressive multifocal leukoencephalopathy (PML)
g. Meningeal carcinomatosis
h. Central nervous system (CNS) toxoplasmosis
i. Multiple sclerosis
j. Hepatic encephalopathy
k. Subacute combined systems disease
l. Meningococcal meningitis
m. Subacute sclerosing panencephalitis (SSPE)
n. AIDS encephalopathy
o. Pickwickian syndrome
214. A 23-year-old woman with a history of hemophilia notices progressive
memory difficulty.
She has required little hematologic support,
but she did receive transfusion of factor
VIII at least five times over the past 7 years.
Neurologic examination reveals word-finding difficulty, poor recent and remote memory, gait ataxia, mild dysarthria, and a labile affect. Her right plantar response is extensor and her left brachioradialis reflex is hyperactive with transient clonus.
An MRI of the brain is unrevealing.
(SELECT 1 DIAGNOSIS)

Answer 24

n. AIDS encephalopathy

Question 25

215. A 35-year-old businessman complains of sleep attacks. He runs a chain of dry cleaning stores, but does not usually work with the cleaning fluids. He reports falling asleep several times during the workday, even at business meetings and during interviews. He has developed the sleep
     attacks only after gaining over 100 lb. His weight at the time of the examination
     is 324 lb. (SELECT 1 DIAGNOSIS)
     a. Postictal state
     b. Hypothyroidism
     c. Uremic encephalopathy
     d. Wernicke’s encephalopathy
     e. Herpes encephalitis
     f. Progressive multifocal leukoencephalopathy (PML)
     g. Meningeal carcinomatosis
     h. Central nervous system (CNS) toxoplasmosis
     i. Multiple sclerosis
     j. Hepatic encephalopathy
     k. Subacute combined systems disease
     l. Meningococcal meningitis
     m. Subacute sclerosing panencephalitis (SSPE)
     n. AIDS encephalopathy
     o. Pickwickian syndrome

Answer 25

o. Pickwickian syndrome

Question 26

216. A 19-year-old man develops obvious personality changes over the course of 2 weeks. He becomes agitated with little provocation and abuses his wife both verbally and physically. His behavior is sufficiently atypical for it to prompt his relatives to seek psychiatric assistance for him. While being interviewed by a psychiatrist, he becomes unresponsive and develops generalized convulsions with opisthotonic posturing, tonic-clonic limb movements, and urinary incontinence. He is hospitalized for investigation of his seizure disorder. On initial examination, he is noted to have a lowgrade fever and a mild left hemiparesis.
     His CSF opening pressure is 210 mmH2O. His CSF cultures yield no growth, and his EEG reveals polyspikeand-wave discharges originating in the right temporal lobe. A CT of his brain reveals focal swelling of the right temporal lobe. (SELECT 1 DIAGNOSIS)
     a. Postictal state
     b. Hypothyroidism
     c. Uremic encephalopathy
     d. Wernicke’s encephalopathy
     e. Herpes encephalitis
     f. Progressive multifocal leukoencephalopathy (PML)
     g. Meningeal carcinomatosis
     h. Central nervous system (CNS) toxoplasmosis
     i. Multiple sclerosis
     j. Hepatic encephalopathy
     k. Subacute combined systems disease
     l. Meningococcal meningitis
     m. Subacute sclerosing panencephalitis (SSPE)
     n. AIDS encephalopathy
     o. Pickwickian syndrome

Answer 26

e. Herpes encephalitis

Question 27

217. A previously healthy 25-year-old woman develops acute loss of vision in her left eye. She awakens with pain in the eye and reduction of her acuity to perception of light and dark. She delays seeing a physician for 1 week, during which time her acuity gradually improves sufficiently to
     allow her to read. On examination, the physician discovers she has slurred
     speech and poor rapid alternating movements with the left hand. Ocular
     dysmetria is evident in both eyes. Her tandem gait is grossly impaired. The
     physician obtains an EEG, which is normal. (SELECT 1 DIAGNOSIS)
     a. Postictal state
     b. Hypothyroidism
     c. Uremic encephalopathy
     d. Wernicke’s encephalopathy
     e. Herpes encephalitis
     f. Progressive multifocal leukoencephalopathy (PML)
     g. Meningeal carcinomatosis
     h. Central nervous system (CNS) toxoplasmosis
     i. Multiple sclerosis
     j. Hepatic encephalopathy
     k. Subacute combined systems disease
     l. Meningococcal meningitis
     m. Subacute sclerosing panencephalitis (SSPE)
     n. AIDS encephalopathy
     o. Pickwickian syndrome

Answer 27

i. Multiple sclerosis

Question 28

218. A 17-year-old man complains of headache and photophobia on awakening. His physician discovers a low-grade fever and resistance to neck flexion. The physician advises the patient to take acetaminophen and remain in bed for the next 24 h. Within 12 h, the patient develops
     nausea and more intense headache. He seems disoriented and inappropriately lethargic. His family brings him to an emergency room. The emergency room physician notes a petechial rash on the legs and marked neck stiffness. CSF examination reveals a glucose content of 5 mg/dL, protein content of 87 mg/dL, and cell count of 112 leukocytes, with 70%
     polymorphonuclear cells. (SELECT 1 DIAGNOSIS)
     a. Postictal state
     b. Hypothyroidism
     c. Uremic encephalopathy
     d. Wernicke’s encephalopathy
     e. Herpes encephalitis
     f. Progressive multifocal leukoencephalopathy (PML)
     g. Meningeal carcinomatosis
     h. Central nervous system (CNS) toxoplasmosis
     i. Multiple sclerosis
     j. Hepatic encephalopathy
     k. Subacute combined systems disease
     l. Meningococcal meningitis
     m. Subacute sclerosing panencephalitis (SSPE)
     n. AIDS encephalopathy
     o. Pickwickian syndrome

Answer 28

l. Meningococcal meningitis

Question 29

219. A 56-year-old man is struck over the parietal area of the head during
     a robbery. He loses consciousness for 35 min but has no focal weakness or
     numbness on recovering consciousness. Within 2 days of the incident, his
     wife finds him unresponsive in bed early in the morning. She calls for an
     ambulance, but before it arrives her husband becomes more alert and asks
     for something to eat, saying he wants to have some supper before he goes
     to bed for the night. The ambulance attendant first on the scene notes that
     the patient is disoriented to place and time and has weakness of his right
     arm and leg. (SELECT 1 DIAGNOSIS)
     a. Postictal state
     b. Hypothyroidism
     c. Uremic encephalopathy
     d. Wernicke’s encephalopathy
     e. Herpes encephalitis
     f. Progressive multifocal leukoencephalopathy (PML)
     g. Meningeal carcinomatosis
     h. Central nervous system (CNS) toxoplasmosis
     i. Multiple sclerosis
     j. Hepatic encephalopathy
     k. Subacute combined systems disease
     l. Meningococcal meningitis
     m. Subacute sclerosing panencephalitis (SSPE)
     n. AIDS encephalopathy
     o. Pickwickian syndrome

Answer 29

a. Postictal state

Question 30

220. A 35-year-old woman is found unconscious on the floor of her
     apartment. A bottle of cleaning fluid is found on a table near her. One of
     the contents indicated in the fluid is carbon tetrachloride. The ambulance
     crew notes that the patient is breathing independently, but her breath has
     a distinctly fetid odor unlike that associated with the cleaning fluid. Her
     limbs are flaccid, and she groans when she is moved. She responds to
     no inquiries and is poorly responsive to pain. A serum ammonia level
     obtained at the emergency room is 250 mg/dL, triple the normal level.
     EEG reveals triphasic waves, most prominently over the front of the head.
     (SELECT 1 DIAGNOSIS)
     a. Postictal state
     b. Hypothyroidism
     c. Uremic encephalopathy
     d. Wernicke’s encephalopathy
     e. Herpes encephalitis
     f. Progressive multifocal leukoencephalopathy (PML)
     g. Meningeal carcinomatosis
     h. Central nervous system (CNS) toxoplasmosis
     i. Multiple sclerosis
     j. Hepatic encephalopathy
     k. Subacute combined systems disease
     l. Meningococcal meningitis
     m. Subacute sclerosing panencephalitis (SSPE)
     n. AIDS encephalopathy
     o. Pickwickian syndrome

Answer 30

j. Hepatic encephalopathy