Basic Human Neuroanatomy
A Clinically Oriented Atlas 

Case History #6

Date of Consultation: 5-24-1987


This 76-year-old white male retired truck driver was admitted to the hospital on 5-24-87 for weakness of his right upper and lower limbs.  The patient was well until 2 days prior to admission.  At that time, while driving his car, he noted that it seemed to be pulling to the right.  This resolved, but the following day he observed some transient difficulties with loss of balance and disequilibrium.  On the day of admission, he awakened to discover a mild to moderate weakness of the right upper and lower limbs.  In the course of the day, his right-sided weakness progressed, and he was hospitalized for further observation.  After hospitalization, his symptoms remained stable, and he experienced no other neurologic symptoms. 


There was no prior history of neurologic disease.  However, the patient had a longstanding history of atrial fibrillation, and he was taking medication for that condition.  He did not have a history of hypertension or diabetes.


Mental Status Exam:  The patient was alert and oriented to person, place, and time.  His vocabulary was excellent, and he had no difficulties with language functions.  His memory and other higher intellectual functions were entirely intact. 

Cranial Nerves:  Sensation of smell was not tested.  Visual field, visual acuity, and funduscopic examinations were normal.  External ocular movements were full without nystagmus or diplopia.  Pupils were equal, round, and reactive to light.  Sensory and motor functions of the Vth cranial nerve were normal.  Weakness of the lower facial muscles on the right was appreciated.  However, the patient was able to wrinkle his forehead, elevate his eyebrows, and close his eyes tightly.  Hearing was intact bilaterally.  XIth cranial nerve functions were normal.  Tongue and palate appeared normal.

Motor System:  There were no areas of focal muscular atrophy.  There were no fasciculations.  Muscle tone was normal in all 4 limbs.  Muscle power was normal on the left side.  On the right side, there was a diffuse, mild to moderate weakness graded at 4/5 in essentially all muscle groups of the right upper and lower limbs.

Reflexes:  Deep tendon reflexes were equal and symmetric bilaterally.  The plantar reflexes were flexor on the left and extensor on the right. 

Sensory System:  The patient perceived all modalities of sensation, including cortical sensations, normally bilaterally.

Cerebellar Function:  Cerebellar tests were performed normally, when allowing for his right-sided weakness. 

Gait and Stance:  The patient's gait was somewhat wide-based with slight circumduction of the right lower limb.  When turning to his right, he tended to stagger.  Tandem gait was not attempted.  The Romberg test was negative.


1.  Considering this patient’s history and physical examination, how precisely can the neurologic lesion be localized in this case?

2.  Indicate the level of the neurologic lesion in this case as precisely as possible and the structures involved by the pathologic process.  If precise localization is not possible, list as many levels and/or structures as you can that might produce the same clinical picture, if involved by the pathologic process.

3.  The findings in this case represent a classic neurologic syndrome.  What is the name of that syndrome, and what is its usual cause?

4.  In general, what type of pathologic process do you think is involved in this case?

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


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