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. Author manuscript; available in PMC: 2015 Sep 10.
Published in final edited form as: Lancet Neurol. 2013 Mar;12(3):310–322. doi: 10.1016/S1474-4422(13)70036-X

Panel 1.

Diagnostic criteria for amyotrophic lateral sclerosis (ALS) derived from El Escorial13 and modified Airlie House criteria14

Diagnosis of ALS requires:
(1) The presence of: (a) evidence of lower motor neuron degeneration by clinical, electrophysiological, or neuropathological examination; (b) evidence of upper motor neuron degeneration by clinical examination; and (c) progression of the motor syndrome within a region or to other regions, as determined by history or examination; and
(2) The absence of: (a) electrophysiological and pathological evidence of other disease processes that might explain the signs of lower or upper motor neuron degeneration; and (b) neuroimaging evidence of other disease processes that might explain the observed clinical and electrophysiological signs.
El Escorial criteria
Definite ALS: upper and lower motor neuron signs in three regions.
Probable ALS: upper and lower motor neuron signs in at least two regions with upper motor neuron signs rostral to lower motor neuron signs.
Possible ALS: upper and lower motor neuron signs in one region, upper motor neuron signs alone in two or more regions, or lower motor neuron signs above upper motor neuron signs.
Suspected ALS: lower motor neuron signs only in two or more regions.
Airlie House (modified) criteria
Clinically definite ALS: clinical evidence alone of upper and lower motor neuron signs in three regions.
Clinically probable ALS: clinical evidence alone of upper and lower motor neuron signs in at least two regions with some upper motor neuron signs rostral to (above) the lower motor neuron signs.
Clinically probable–laboratory-supported ALS: clinical signs of upper and lower motor neuron dysfunction are in only one region, or upper motor neuron signs alone in one region with lower motor neuron signs defined by electromyography criteria in at least two limbs, together with proper application of neuroimaging and clinical laboratory protocols to exclude other causes.
Possible ALS: clinical signs of upper and lower motor neuron dysfunction in only one region, or upper motor neuron signs alone in two or more regions; or lower motor neuron signs rostral to upper motor neuron signs and the diagnosis of clinically probable-laboratory-supported ALS cannot be proven.
Suspected ALS: this category has been deleted from the revised El Escorial criteria.