A 39-year-old man is brought to the
emergency department (ED)
after his car struck a tree. He experienced
a transient loss of consciousness
with a 3-minute episode of retrograde
amnesia at the scene of the accident,
despite wearing a seat belt and
shoulder harness. He was disoriented
to date and place.
Now, in the ED, his pulse rate is
98 beats per minute; respiration rate,
20 breaths per minute; and blood
pressure, 140/90 mm Hg. Temperature
is not recorded. He complains of
occipital headache and numbness
and tingling in his left arm. He has a
3-cm tender area in the occipital
scalp; there is no swelling or bony depression.
Grip in the left hand and
flexion and extension of the left forearm
are weak. His left arm demonstrates
a mild pronator drift; sensory
testing reveals diminished sensation
in the arm. His speech is slow, and
he is unable to relate the history of
the crash. Heart, lungs, and abdomen
He began having problems
with his left arm 2 weeks earlier. He
also had difficulty in walking and
seemed confused. He was examined
in the ED and told he might have had a stroke; however, a
head CT scan was normal.
He has a history of coronary artery disease and
hypercholesterolemia and takes atenolol, 25 mg/d, and
lisinopril, 10 mg/d, for hypertension. He smokes 1 pack of
cigarettes daily and was a heavy drinker in the past. No
history of seizures or neurologic disease.
A noncontrast head CT scan and cervical spine x-ray
series are ordered.
What clues to the cause of this patient's symptoms
are evident in the scan?