Table 1.

Summary of Revised El Escorial Research Diagnostic Criteria for ALS (Brooks et al., 2000)

The diagnosis of ALS requires:
1 Evidence of LMN degeneration by clinical, electrophysiological or neuropathological examination;
2 Evidence of UMN degeneration by clinical examination, and
3 Progressive spread of symptoms or signs within a region or to other regions, as determined by history or examination,
Together with the absence of:
[1] Electrophysiological and pathological evidence of other disease that might explain the signs of LMN and/or UMN degeneration, and
[2] Neuroimaging evidence of other disease processes that might explain the observed clinical and electrophysiological signs
Categories of clinical diagnostic certainty on clinical criteria alone
Definite ALS
• UMN signs and LMN signs in 3 regions Probable ALS
• UMN signs and LMN signs in 2 regions with at least some UMN signs rostral to LMN signs
Probable ALS – Laboratory supported
• UMN signs in 1 or more regions and LMN signs defined by EMG in at least 2 regions
Possible ALS
• UMN signs and LMN signs in 1 region (together), or
• UMN signs in 2 or more regions
• UMN and LMN signs in 2 regions with no UMN signs rostral to LMN signs

UMN signs: clonus, Babinski sign, absent abdominal skin reflexes, hypertonia, loss of dexterity.

LMN signs: atrophy, weakness. If only fasciculation: search with EMG for active denervation.

Regions reflect neuronal pools: bulbar, cervical, thoracic and lumbosacral.