clinical neurology soal 37-70

Question 36

Which of the following is not a characteristic of Adie’s syndrome?
A. degeneration of the ciliary ganglia and postganglionic parasympathetics
B. more common in women than in men
C. no reaction to 0.1% pilocarpine solution
D. paralysis of segments of the pupillary sphincter
E. Pupil responds better to near than to light.

Answer 36

C. no reaction to 0.1% pilocarpine solutionV&A p. 297. An Adie’s pupil is unusually sensitive to 0.1% pilocarpine (dener- ation hypersensitivity).

Question 37

Characteristics of  infantile seizures include 
I.  lip smacking 
11.  hypsarrythmia 
111.  generalized tonic-clonic activity 
IV.  myoclonic head jerks 
A.  I.  11,  111 
B.  I,  111 
C.  11,  IV 
D.  IV 
E.  all of  the  above

Answer 37

C. II, IV V&A p. 352. Infantile seizures or spasms usually begin before 6 months of age and are characterized by sudden flexor or extensor spasms of the head, trunk. and limbs and an electroencephalogram (EEG) picture of bilateral high- voltage, slow-wave activity (hypsarrythmia). Lip smacking and generalized onic-clonic activity are not features.

Question 38

Muscles of the trunk and lower extremities are more frequently involved than the extraocular muscles
A. myasthenia gravis
B. myasthenic syndrome of Eaton-Lambert
C. both
D. neither

Answer 38

B. myasthenic syndrome of Eaton-Lambert For questions 39-42 see V&A pp. 1547-1548. These are all features of the Eaton-Lambert syndrome.

Question 39

Poor response to anticholinesterase drugs
A. myasthenia gravis
B. myasthenic syndrome of Eaton-Lambert
C. both
D. neither

Answer 39

B. myasthenic syndrome of Eaton-Lambert

Question 40

An incrementing response (marked increase in the amplitude of the action potential with,,fast rates of nerve stimulation) is typical.
A. myasthenia gravis
B. myasthenic syndrome of Eaton-Lambert
C. both
D. neither

Answer 40

B. myasthenic syndrome of Eaton-Lambert

Question 41

associated with antibodies to the presynaptic voltage-dependent calcium channel
A. myasthenia gravis
B. myasthenic syndrome of Eaton-Lambert
C. both
D. neither

Answer 41

B. myasthenic syndrome of Eaton-Lambert

Question 42

The  dorsal scapular nerve innervates the 
I.  supraspinatus 
11.  rhomboids 
111.  subscapularis 
IV.  levator  scapulae 
A.  I,  11,111 
B.  I, 111 
C  11,  IV 
D.  IV 
E.  all of  the  above

Answer 42

C. 11. rhomboids , IV. levator scapulae

Question 43

teres major

A.  axillary nerve 
B.  dorsal scapular nerve 
C.  subscapular  nerve 
D.  suprascapular nerve 
E.  none of  the  above

Answer 43

C. subscapular nerve

Question 44

teres minor

A.  axillary nerve 
B.  dorsal scapular nerve 
C.  subscapular  nerve 
D.  suprascapular nerve 
E.  none of  the  above

Answer 44

A. axillary nerve

Question 45

subscapularis 
A.  axillary nerve 
B.  dorsal scapular nerve 
C.  subscapular  nerve 
D.  suprascapular nerve 
E.  none of  the  above

Answer 45

C. subscapular nerve

Question 46

levator  scapulae 
A.  axillary nerve 
B.  dorsal scapular nerve 
C.  subscapular  nerve 
D.  suprascapular nerve 
E.  none of  the  above

Answer 46

B. dorsal scapular nerve

Question 47

supraspinatus 
A.  axillary nerve 
B.  dorsal scapular nerve 
C.  subscapular  nerve 
D.  suprascapular nerve 
E.  none of  the  above

Answer 47

D. suprascapular nerve

Question 48

infraspinatus 
A.  axillary nerve 
B.  dorsal scapular nerve 
C.  subscapular  nerve 
D.  suprascapular nerve 
E.  none of  the  above

Answer 48

D. suprascapular nerve

Question 49

rhomboids
 A.  axillary nerve 
B.  dorsal scapular nerve 
C.  subscapular  nerve 
D.  suprascapular nerve 
E.  none of  the  above

Answer 49

B. dorsal scapular nerve

Question 50

The motor unit potential in myopathy is of
A. decreased voltage and decreased duration
B. decreased voltage and increased duration
C. decreased voltage and normal duration
D. normal voltage and decreased duration
E. normal voltage and increased duration

Answer 50

A. decreased voltage and decreased duration

Question 51

Which is true of myotonic dystrophy?
A. Frontal balding occurs only in men.
B. Lens abnormalities are rare.
C The congenital form is inherited only from the maternal line.
D. The inheritance is autosomal recessive.
E. Weakness always predates the myotonia.

Answer 51

C The congenital form is inherited only from the maternal line. V&A pp. 1503-1504. Frontal balding occurs in both men and women afflicted with myotonic dystrophy. Lens opacities are found by slit lamp in 90% of patients. The inheritance is autosomal dominant, and the defective gene segregates on chromosone 19. Myotonia may precede weakness by several years. Answer C is correct.

Question 52

Subacute  combined degeneration of  the  spinal  cord is  caused  by a  deficiency of 
A.  cobalamin 
B.  folic acid 
C.  nicotinic  acid 
D.  pyridoxine 
E.  thiamine

Answer 52

A. cobalamin V&A p. 1218. Subacute combined deficiency of the cord occurs from failure totransfer cobalamin (vitamin BIZ) across the interstitial mucosa because of lackof intrinsic factor.

Question 53

The  marker linked  to the  Huntington  gene is  localized  to the  short  arm  of chromosome
A.  4 
B.  11 
C.  17 
D.  22 
E.  none of  the  above

Answer 53

A.4

Question 54

Alexia without agraphia is most likely to occur with a lesion involving the
A. left geniculocalcarine tract and corpus callosum
B. left geniculocalcarine tract and Wernicke’s area
C. left geniculocalcarine tract, corpus callosum, and Wernicke’s area
D. right geniculocalcarine tract and corpus callosum
E. right geniculocalcarine tract and Wernicke’s area

Answer 54

A. left geniculocalcarine tract and corpus callosum V&A pp. 494,511. The lesion described in A would render the patient blind in the right half of the visual field. Visual information reaches only the right occipital lobe but cannot be transferred to Wernicke’s area across the callo- sum. Thus the ability to read aloud and to understand the written word is lost, but the ability to understand the spoken language, speak, write, dictate, and converse is retained.

Question 55

Deviation of the eyes to the right is most likely to occur with occlusion of the A. calcarine artery bilaterally
B. calcarine artery on the contralateral side
C. contralateral paramedian branch of the basilar artery
D. ipsilateral superior cerebellar artery
E. superior division of the contralateral middle cerebral artery

Answer 55

C. contralateral paramedian branch of the basilar artery V&A p. 849. Deviation of the eyes away from the lesion occurs in brainstem syndromes, for example, the medial midpontine syndrome (occlusion of the paramedian branch of the midbasilar artery). Answers B, D, and E would cause deviation of the eyes to the left.

Question 56

Which of  the  following antiepileptic drugs has the  shortest half-life? 
A.  carbamazepine 
B.  ethosuximide 
C.  phenobarbital 
D.  phenytoin 
E.  valproate

Answer 56

E. valproate Of the antiepileptic drugs listed, phenobarbital has the longest half-life of 96 k 12 hours, followed by ethosuximide, 40 k 6 hours; phenytoin 24 k 12 hours; carbamazepine 12 k 4 hours; and valproate 8 f 2 hours.

Question 57

weakness and atrophy  of  the  hands 
A.  amyotrophic lateral  sclerosis 
B.  syringomyelia 
C.  both 
D.  neither

Answer 57

C. both
Despite the atrophy of the hands and forearms in amyotrophic lateral sclerosis (ALS), diffuse hyperreflexia is seen, with absence of sensory change.

Question 58

hypo- or areflexia
A.  amyotrophic lateral  sclerosis 
B.  syringomyelia
C.  both
D.  neither

Answer 58

B . syringomyelia
Despite the atrophy of the hands and forearms in amyotrophic lateral sclerosis (ALS), diffuse hyperreflexia is seen, with absence of sensory change.

Question 59

absence of  sensory changes 
A.  amyotrophic lateral  sclerosis 
B.  syringomyelia 
C.  both 
D.  neither

Answer 59

A amyotrophic lateral sclerosis
Despite the atrophy of the hands and forearms in amyotrophic lateral sclerosis (ALS), diffuse hyperreflexia is seen, with absence of sensory change.

Question 60

Biochemical studies of neurons from a seizure focus have shown all of the ollowing except A. increased levels of extracellular potassium in glial scars near seizure foci . B. decreased rate of binding and removing acetylcholine in the foci . C. deficiency of y-aminobutyric acid (GABA) D. decreased glycine levels . E. decreased taurine levels

Answer 60

D. decreased glycine levels . | V&A p. 345. Increased glycine levels have been found in neurons in seizure foci.

Question 61

The most reliable indicator of an intracellular cobalamin (vitamin B12deficiency is A. low vitamin B12 on a microbiologic assay B. low vitamin B12 on a radioisotope dilution assay C. low vitamin Biz on a Schilling test D. the finding of hypersegmented polymorphonuclear neutrophil leukocytes (PMN) in bone marrow smears E. the finding of increased serum concentration of methylmalonic acid and homocysteine

Answer 61

E. the finding of increased serum concentration of methylmalonic acid and homocysteine V&A p. 1222. Although microbiologic assay is the most accurate way to mea- sure serum cobalamin levels, the serum level is not a measure of total body cobalamin. High serum concentrations of cobalamin metabolites (methyl- malonic acid and homocysteine) are the most reliable indicators of an intra- cellular cobalamin deficiency.

Question 62

Each of the following is true of radiation myelopathy (delayed progressive type) except A. Absence of pain is typical early in the course. B. It occurs 12 to 15 months after radiation. C. Magnetic resonance imaging (MRI) shows abnormal signal intensity; decreased on TI and increased on T2. D. Sensory changes usually develop after motor changes. E. The most severe parenchymal changes are typical of infarction.

Answer 62

D. Sensory changes usually develop after motor changes. | V&A p. 1302. In radiation myelopathy, sensory changes usually precede theweakness.

Question 63

``` Fasciculation potentials indicate A. motor nerve fiber irritability B. motor nerve fiber destruction C motor unit denervation D. muscle atrophy E. reinnervation of muscle units ```

Answer 63

A. motor nerve fiber irritability

Question 64

``` di- or triphasic pattern A. fasciculation potential B. fibrillation potential C. both D. neither ```

Answer 64

B. fibrillation potential

Question 65

``` 5 to 15 ms in duration A. fasciculation potential B. fibrillation potential C. both D. neither ```

Answer 65

A. fasciculation potential

Question 66

``` may take the form of positive sharp waves A. fasciculation potential B. fibrillation potential C. both D. neither ```

Answer 66

B. fibrillation potential

Question 67

``` seen in poliomyelitis A. fasciculation potential B. fibrillation potential C. both D. neither ```

Answer 67

C. both

Question 68

``` usually develops 24 to 36 hours after the death of an axon A. fasciculation potential B. fibrillation potential C. both D. neither ```

Answer 68

D. neither

Question 69

``` may be visible through the skin A. fasciculation potential B. fibrillation potential C. both D. neither ```

Answer 69

A. fasciculation potential For questions 65-70 see V&A pp. 1361-1362. Fibrillation potentials last from 1 to 5 ms, may take the form of positive sharp waves, and are seen 10 to 25 days after the death of an axon. Fasciculation potentials have three to five phases. Both can be seen in poliomyelitis.