Basic Human Neuroanatomy
A Clinically Oriented Atlas 


Case History #178

Date of Consultation: 12-14-1989


HISTORY OF PRESENT ILLNESS:

This 43-year-old right-handed white female tax auditor was referred for neurologic evaluation due to her headache problem.  The patient states her headache problem began 9 months ago (March 1989), at approximately the same time that she developed an episode of impaired vision in her right eye.  She knows of no other specific circumstances surrounding the onset of the problem.  She denies any prior difficulties with headaches.  Since their onset, her headaches have been present constantly, 24 hours a day, although they have fluctuated in intensity.  No specific neurologic signs or symptoms occur either before, during, or in between headache attacks.  She describes the pain as being in the right frontal, temporal, and parietal regions, and she indicates that the pain is a steady, aching, pressure-like sensation.  She is experiencing no autonomic or systemic signs or symptoms associated with the headache except for occasional nausea. 

In March of 1989, the patient had the acute onset of flashing lights, eye pain, and pain on eye movement in the right eye.  Her visual acuity gradually diminished over a two to three week period of time until it reached the point of her being able to perceive hand motion only in the right eye.  The patient was seen by a neuro-ophthalmologist who placed her on prednisone.  Her visual acuity gradually recovered from that point up to the present time.  Her last recorded visual acuity on 12-12-89 was 20/40 in the right eye, and her visual field examination was vastly improved.
 
In addition to the headache and the episode of right visual impairment, the only other item in her past neurologic history is that of bilateral numbness and tingling involving both upper limbs.  These symptoms came on initially after a motor vehicle accident in 1987 and have persisted to the present.  The symptoms are particularly severe at night and will often awaken her from sleep.  She does not complain of a Lhermitte’s phenomenon.

NEUROLOGICAL EXAMINATION:

Mental Status Exam:  Intact.

Cranial Nerves:  Sensation of smell was intact bilaterally.  Visual acuity was J3 in the right eye and J1 in the left eye without her glasses.  Visual fields were full to confrontation.  Funduscopic examination was normal on the left but revealed optic pallor on the right.  There was a 1+ afferent pupillary defect on the right and about 50 per cent color desaturation in the right eye.  Otherwise, pupils were equal and reactive normally to light and accommodation, except for the afferent pupillary defect.  External ocular movements were full without nystagmus or diplopia.  Sensory and motor functions of the Vth cranial nerve were normal.  There was no facial weakness.  Hearing was intact bilaterally.  XIth cranial nerve functions were normal.  Tongue and palate appeared normal.

Motor System:  There was no evidence of focal or generalized muscular atrophy.  There were no fasciculations.  Muscle tone and power were normal in all 4 limbs. 

Reflexes:  Deep tendon reflexes were equal and symmetric, and the plantar reflexes were flexor bilaterally. 

Sensory System:  All modalities of sensation, including cortical sensations, were normal, except for decreased appreciation to pinprick involving the right thumb and skin over the first dorsal interosseous space of the right hand.

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 (APD, Marcus Gunn pupil), what is its anatomical basis, and what localizing significance does it have?

3.  What specific structure(s) is involved by the pathologic process in this case?
 
4.  How would you describe or characterize this patient’s visual problems in the right eye?

5.  How would you characterize or classify this patient’s headache problem?  Do you think that the patient’s headache problem and visual problem are related?

6.  In general, what type of pathologic process was involved in this case?

7.  What is your tentative diagnosis or diagnoses in this case?  What other considerations would be in this patient’s differential diagnosis? 

8.  What diagnostic procedure(s) would you undertake at this point?

Answers
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