Case History #47
Date of Consultation: 6-1-1979
HISTORY OF PRESENT ILLNESS:
This 61-year-old right-handed white male shop owner was referred for
neurologic consultation for evaluation of a visual problem in the left
eye. On 5-24-79, the patient noted the acute onset of decreased
vision in the inferior aspect of the visual field of his left
eye. He described this as a gray, hazy blank area occupying both
inferior quadrants of his left eye only. He did close the left
eye and noted that the vision out of his right eye was entirely
normal. When he closed the right eye, the inferior visual field
defect was present. He denied any other symptoms in the eye
including eye pain, foreign body sensation, pain on extraocular
movements, diplopia, or other visual field changes. An
ophthalmologist saw the patient and felt that there was papilledema of
the optic disc in the left eye.
NEUROLOGICAL EXAMINATION:
Mental Status Exam: Intact.
Cranial Nerves:
Cranial nerve examination was normal except for the following.
Funduscopic examination revealed moderate disc swelling in the left eye
with no spontaneous venous pulsations seen. In the right eye,
there was no papilledema present. Visual field testing revealed
full visual fields in the right eye. In the left eye, there was
an inability to perceive objects in the medial (nasal) and lateral
(temporal) inferior quadrants. There was a 2+ afferent pupillary
defect (APD) on the left. Visual acuity was 20/20 in both
eyes. There was no abnormality of external ocular movements or
pupillary responses except for the APD.
Motor System: Intact.
Reflexes:
Intact.
Sensory System: Intact.
Cerebellar Function: Intact.
Gait and Stance: Intact.
Questions
1. Where in the visual
pathway would you localize the lesion in this case (optic nerve, optic
chiasma, optic tract, optic radiations, or occipital cortex)?
2. What is an afferent pupillary defect (Marcus Gunn pupil), what
is its anatomical basis, and what localizing significance does it have?
3. What side of the nervous system is involved in this
case? What specific structure(s) is involved by the pathologic
process?
4. In general, what type of pathologic process was involved in
this case?
5. What diagnostic procedure(s) would you undertake at this point?
