at the spinal tap. One would not want to give TPA to a patient with a hem-
orrhagic stroke because it would probably make conditions worse. The CT
was normal because the blood vessel had spontaneously stopped bleeding
and the amount of blood was too small to detect radiographically. Subdural
hematoma(answer c),while common in the elderly, would notresult in a
bloody spinal tap. Epidural hematoma (answer d)wouldnotresult in a
bloody spinal tap. Alzheimer’s dementia (answer e)has nothing to do with
this case.
303.The answer is c.(Moore and Dalley, p 1154.)Atrophy of the intrinsic
musculature of the tongue on one side is due to a lesion of the ipsilateral
hypoglossal nerve. Deviation of the tongue to the right on protrusion
results from the unopposed action of the left genioglossus muscle, which is
innervated by the left hypoglossal nerve. The hypoglossal nerve also inner-
vates numerous other tongue muscles involved in deglutition. The ques-
tion only asks about the cause of the tongue deviation so the other answers
(answers a, b, d, e)are irrelevant.
304.The answer is e.(Moore and Dalley, p 1142.)The abducent nerve
(CN VI) innervates the lateral rectus muscle. Remember, the “formula”
LR 6 SO 4. Lateral rectus is innervated by CN VI, superior oblique by CN IV
and the remainder of the extrinsic eye muscles by CN III. Loss of innerva-
tion to the lateral rectus results in unopposed tension by the medial rectus,
which produces internal strabismus. The oculomotor nerve (CN III) inner-
vates the medial, superior, and inferior recti, the inferior oblique, and the
levator palpebrae superioris muscles. Paralysis of this nerve (answer b)
would result in lateral deviation of the eye (external strabismus) accompa-
nied by ptosis (drooping eyelid). In addition, mydriasis (dilated pupil)
results from loss of function of the parasympathetic component of the ocu-
lomotor nerve. Damage to the trochlear nerve (CN IV) results in paralysis
of the superior oblique muscle with impaired ability to direct the eye
downward and outward (answer c).The optic nerve (answer a)is respon-
sible for receiving the special sense of sight. The trigeminal cranial nerve
(answer d)carries pain information from the eye.
305.The answer is a.(Moore and Dalley, p 1069.)The stylohyoid mus-
cle inserts onto the lesser horn of the hyoid bone (both derivatives of the
Head and Neck Answers 447