General Flashcards
- Which of the following is FALSE regarding myasthenia gravis?
A. The fi rst presentation is usually weakness of the extraocular muscles.
B. Weakness fl uctuates and fatigues over the course of the day.
C. Speech may be hypernasal or hoarse in some patients.
D. It may present with a head drop.
E. Dysphagia is worst at breakfast and improves during the course of the day
11.E. Dysphagia in myasthenia gravis is fatigable, and the patient often relates a history of little difficulty with breakfast, moderate difficulty with lunch, and inability to eat in the evening.
- All of the following are true of polymyositis EXCEPT:
A. It involves a symmetric weakness of proximal limb and trunk muscles.
B. Its onset is insidious.
C. Ocular muscles are usually spared.
D. Muscles are not tender to palpation.
E. Skin changes typically occur before muscle abnormalities.
12.E. Skin changes precede muscle abnormalities in dermatomyositis (DM). Polymyositis (PM) is diagnosed by fibrillation potentials on electromyography
(EMG) and elevated creatine phosphokinase (CPK) levels (higher than those for DM). In polymyositis, there is widespread single-fi ber necrosis, and T cells
with macrophages may be found in the muscle fibers. PM is the most frequent inflammatory myopathy
- Protein 14-3-3 is elevated in the CSF in which of the following conditions?
A. Creutzfeldt-Jakob disease B. Demyelinating disease C. Head trauma D. Meningoencephalitis E. All of the above
13.E. Protein 14-3-3 is elevated in the cerebrospinal fluid (CSF) with destructive diseases of the central nervous system (CNS). This protein is sensitive for
Creutzfeldt-Jakob disease, but not specific.
- Which of the following is FALSE regarding the sonic hedgehog (SHH) gene?
A. SHH has been found to have the critical roles in development of the limb
and midline structures in the brain and spinal cord.
B. Mutations in the human SHH gene, cause holoprosencephaly type 3 as a
result of the loss of the ventral midline.
C. The SHH transcription pathway has been linked to the formation of embryonic cerebellar tumors such as medulloblastoma.
D. SHH has been shown to act as an axonal guidance cue: SHH attracts retinal ganglion cell axons at high concentrations and repels them at lower
concentrations.
E. SHH plays a critical role in the induction of the floor plate and diverse ventral cell types within the neural tube.
16.D. SHH has been found to have the critical roles in development of the limb and
midline structures in the brain and spinal cord. Mutations in the human SHH
gene cause holoprosencephaly type 3 as a result of the loss of the ventral midline. SHH is secreted at the zone of polarizing activity located on the posterior
side of a limb bud in an embryo. The SHH transcription pathway has also been
linked to the formation of embryonic cerebellar tumors such as medulloblastoma. SHH has been shown to act as an axonal guidance cue: SHH attracts retinal
ganglion cell axons at low concentrations and repels them at higher concentrations. SHH plays a critical role in the induction of the floor plate and diverse
ventral cell types within the neural tube.
- All the following are potential contraindications for vagal nerve stimulation
placement EXCEPT:
A. Upper cranial nerve defi cits B. Presence of a single vagus nerve only C. Cardiac arrhythmias D. Lung disease E. Ulcers
19.A. While lower cranial nerve dysfunction may be a relative contraindication for
vagal nerve stimulation, upper cranial nerve deficits do not represent such a
contraindication.
