Download Case for LU#4. Mysterious paralysis

Case for LU#4.
Mysterious paralysis
“Like a polio ward from the 1950s” is how Guy McKhann, MD, neurologist, describes a section
of Beijing Hospital that he visited on a trip to China in 1986. Dozens of paralyzed children –
some attached to respirators to assist their breathing – filled the ward to overflowing. The
Chinese doctors thought the children had Guillain-Barre syndrome (GBS), an unusually rare
paralytic condition. But Dr. McKhann wasn’t as convinced. There were simply too many stricken
children for the illness to be the rare Guillain-Barre syndrome. Was it polio – as some of the
Beijing staff feared? Or was it another illness, perhaps one that not yet been discovered?
Insightful info:
Guillain-Barre syndrome is a rare paralytic condition that strikes after a viral infection or
immunization. There is nor cure, but usually the paralysis and lost sensation slowly disappear.
In classic Guillain-Barre syndrome, patients can neither feel sensations or move their muscles.
Q#1. Which division of the nervous system may be involved in Guillain-Barre syndrome?
In classic Guillain-Barre syndrome, the disease affects both sensory and somatic motor neurons.
Dr. McKhann observed that, although the Beijing children could not move their muscles, they
could feel a pin prick.
Q#2. Do you think that the paralysis found in the Chinese children affect both sensory and
somatic motor neurons? Why or why not?
Like multiple sclerosis, Guillain-Barre syndrome is an illness in which myelin that insulates axons
is destroyed. One way that multiple sclerosis and other demyelinating illnesses are diagnosed is
through the use of a nerve conduction test. This test measures the combined strength of action
potentials and the rate at which they are conducted as they travel down neurons.
Q#3. In Guillain-Barre syndrome, what would you expect the results of a nerve conduction
test to be?
Dr. McKhann decided to perform nerve conduction tests on some of the paralyzed children. He
found that, although the rate of conduction along the children’s neurons was normal, the
action potentials were greatly diminished.
Q#4. Is the paralytic illness that affected the Chinese children a demyelinating condition? Why
or why not?
Dr. McKhann then asked to see autopsy records on some of the children who had died of their
paralysis at Beijing Hospital. In the reports, pathologists noticed that the patients had normal
myelin but damaged axons. In some cases, the axon had been completely destroyed, leaving
only a hollow shell of myelin.
Q#5. Do the results of Dr. McKhann’s investigation and autopsy suggest that the Chinese
children had Guillain-Barre syndrome? Why or why not?
Currently, Dr. McKhann believes that the disease afflicting the Chinese ch9ildren – which he has
named acute axonal polyneuropathy (AMAN) – may be caused by bacterial infection. He also
believes that the disease initiates its damage of axons at neuromuscular junctions.
Q#6. Based on information provided and your study materials, can you name another disease
that alters synaptic transmission?
In this case, you learned about a paralytic illness that appears to be a new disease.
Although it bears some resemblance to Guillain-Barre syndrome, upon closer investigation it, it
actually has some significantly different features.
Note: Dr. McKhann’s Original Report is available at Lancet 338 8767): 593-597, 1991 Sept 7.
Case adapted from Silvertborn. Human Physiology, Third ed. Pearson. 2004.