http://www.neurology.org/cgi/content/abstract/57/7/1248
Neurology 2001;57:1248-1252
Axonal loss in normal-appearing white
matter in a patient with acute MS
Address correspondence and reprint
requests to Dr. Bruce D. Trapp, Department of Neurosciences, Lerner Research
Institute, Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland,
OH 44195; e-mail: trappb@ccf.org
Background:
Brain imaging studies detect abnormalities
in normal-appearing white matter in patients with MS.
Objective:
To investigate the histopathologic
basis for these changes in autopsy tissue from a patient with MS with 9
months’ disease duration and a terminal brain stem lesion.
Methods:
The brain stem and spinal cord were
analyzed ultrastructurally and immunocytochemically for axons, myelin,
and activated microglia/macrophages.
Results:
Pathologic findings were consistent
with a terminal inflammatory demyelinated lesion at the cervicomedullary
junction. The ventral spinal cord column, containing descending tracts,
exhibited 22% axonal loss at segment C7, but grossly normal immunostaining
for myelin. Confocal and electron microscopy revealed myelin sheaths without
axonal content and initial stages of myelin degradation by activated microglia/macrophages
among intact myelinated axons. Axonal number and appearance was normal
in ascending sensory tracts.
Conclusions:
These studies confirm axonal degeneration
in the absence of myelin loss as one histopathologic correlate to abnormal
MR findings in patients with MS.
© 2001 American Academy of Neurology
C. Bjartmar, MD PhD;, R. P. Kinkel,
MD, G. Kidd, PhD, R. A. Rudick, MD and B. D. Trapp, PhD
From the Department of Neurosciences,
Lerner Research Institute (Drs. Bjartmar, Kidd, Rudick, and Trapp), Department
of Neurology (Mellen Center) (Drs. Kinkel and Rudick), and the Center for
Clinical Research (Dr. Rudick), Cleveland Clinic Foundation, OH.