Corticospinal tract degeneration in the progressive muscular atrophy variant of ALS.
OBJECTIVE
Examining the unresolved relationship between the lower motor neuron disorder progressive muscular atrophy (PMA) and ALS is important in clinical practice because of emerging therapies.


METHODS
Spinal and brainstem tissues donated from patients with ALS/motor neuron disorder (n = 81) were examined. Using retrospective case note review, the authors assigned patients into three categories: PMA (12), PMA progressing to ALS (6), and ALS ab initio (63). Conventional stains for long tract degeneration and immunocytochemistry for ubiquitin and the macrophage marker CD68 were examined.


RESULTS
Rapid progression and typical ubiquitinated inclusions in lower motor neurons were present in 77 (95%) of the cases. Immunocytochemistry for CD68 was a more sensitive marker of long tract pathology in comparison with conventional stains. Half of the cases with PMA showed corticospinal tract degeneration by CD68.


CONCLUSIONS
Patients with PMA frequently have undetected long tract pathology and most have ubiquitinated inclusions typical of ALS. A patient presenting with PMA with rapid clinical evolution likely has the pathology and pathophysiology of ALS whether or not upper motor neuron signs evolve.
Ince
P G
PG
Neuropathology, Academic Unit of Pathology, Division of Genomic Medicine, Sheffield University, UK. p.g.ince@shef.ac.uk
Evans
J
J
Knopp
M
M
Forster
G
G
Hamdalla
H H M
HH
Wharton
S B
SB
Shaw
P J
PJ
D000368:Aged; D000690:Amyotrophic Lateral Sclerosis / Q000145:classification / Q000473:pathology*; D015703:Antigens, CD / Q000032:analysis; D015214:Antigens, Differentiation, Myelomonocytic / Q000032:analysis; D018450:Disease Progression; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009134:Muscular Atrophy, Spinal / Q000473:pathology*; D020671:Posterior Horn Cells / Q000473:pathology; D011712:Pyramidal Tracts / Q000737:chemistry / Q000473:pathology*; D025801:Ubiquitin / Q000032:analysis; D000097382:CD68 Molecule
D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic; D025801:Ubiquitin; C067980:CD68 antigen, human; D000097382:CD68 Molecule