CNS nontumor
Motor neuron disorders
Amyotrophic lateral sclerosis (ALS)


Topic Completed: 1 September 2016

Revised: 20 August 2019

Copyright: (c) 2002-2019, PathologyOutlines.com, Inc.

PubMed Search: Amyotrophic lateral sclerosis CNS [title]

Margaret E. Flanagan, M.D.
Thomas J. Montine, M.D., Ph.D.
Page views in 2018: 2,301
Page views in 2019 to date: 2,267
Cite this page: Flanagan ME, Montine TJ, Plowey E. Amytrophic lateral sclerosis (ALS). PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/cnsals.html. Accessed September 22nd, 2019.
Definition / general
Essential features
  • Spinal cord and anterior spinal root atrophy
  • Upper and motor neuron loss with associated loss of myelinated axons
  • Neuronal inclusions:
    • Skein-like inclusions
    • Hyaline (Lewy-like) inclusions
    • Bunina bodies
Terminology
  • Popularly known as Lou Gehrig disease (Wikipedia: Lou Gehrig)
  • Progressive bulbar palsy (PBP) and progressive muscular atrophy (PMA) are generally considered to be variants of a single clinicopathologic syndrome (Ellison: Neuropathology - A Reference Text of CNS Pathology, Third Edition, 2013)
    • PBP: syndrome of progressive dysarthria and dysphagia
      • ~25% of patients who develop other features of ALS initially present with PBP
    • PMA: condition where lower motor neuron signs correlating with loss of anterior horn cells occur in absence of upper motor neuron signs
      • Upper motor neurons are preserved
  • Primary lateral sclerosis (PLS) is usually regarded as a distinct entity because of the lack of lower motor neuron (LMN) involvement (Ellison: Neuropathology - A Reference Text of CNS Pathology, Third Edition, 2013)
    • PLS: upper motor neuron signs occur in the absence of lower neuron signs
      • Pathologic changes are confined to motor cortex and cortical spinal tracts
Epidemiology
Sites
  • Anterior spinal roots
  • Spinal cord
  • Hypoglossal nucleus
  • Primary motor cortex
  • Brain stem motor nuclei
Pathophysiology
Genetic factors
Clinical features
Diagnosis
  • Diagnosis of ALS requires (Ellison: Neuropathology - A Reference Text of CNS Pathology, Third Edition, 2013):
    • Presence of:
      • Evidence of lower motor neuron (LMN) degeneration by clinical, electrophysiological or neuropathological examination
      • Evidence of upper motor neuron (UMN) degeneration by clinical examination
      • Progression of the motor syndrome within a region or to other region, as determined by history or examination
    • Absence of:
      • Electrophysiological and pathological evidence of other disease processes that might explain the signs of LMN or UMN degeneration
      • Neuroimaging evidence of other disease processes that might explain the observed clinical and electrophysiological signs
Radiology description
Prognostic factors
Gross description
Gross images

Contributed by Hannes Vogel, M.D.
Missing Image

ALS

Microscopic (histologic) description
Microscopic (histologic) images

Contributed by Hannes Vogel, M.D.
Missing Image

Missing Image

Various images

Positive stains
Negative stains
Back to top