Table 1

 Revised diagnostic criteria for classical and variant RS. Derived from tables 3 and 4 in the paper by Hagberg et al.8

Necessary criteriaSupportive criteriaExclusion criteria
Classical RSApparently normal prenatal and perinatal historyBreathing disturbances while awake BruxismOrganomegaly or other evidence of a storage disorder
Psychomotor development normal during the first 6 months (may be delayed from birth)Impaired sleeping pattern from early infancy Abnormal muscle tone accompaniedRetinopathy, cataract, or optic atrophy History of perinatal or postnatal brain damage
Normal head circumference at birthby muscle wasting and dystoniaIdentifiable inborn error of metabolism
Postnatal deceleration of head growth (most individuals)Abnormal muscle tone accompanied by muscle wasting and dystoniaor neurodegenerative disorder Acquired neurological disorder due to
Loss of purposeful hand skills between 0.5–2.5 yearsPeripheral vasomotor disturbances Progressive scoliosis or kyphosissevere infection or head trauma
Stereotypic hand movementsGrowth retardation
Evolving social withdrawal, communication dysfunction, loss of acquired speech, cognitive impairmentHypotrophic small and cold feet and/or hands
Impaired or deteriorating locomotion
Variant RSAt least 3 of the 6 main criteriaBreathing irregularities
At least 5 of the 11 supportive criteriaAir swallowing or abdominal bloating
Main criteriaBruxism
 Absence or reduction of hand skillsAbnormal locomotion
 Reduction or loss of speech (including babble)Scoliosis or kyphosis
 Hand stereotypiesLower limb amyotrophy
 Reduction or loss of communication skillsCold, discoloured feet, usually hypotrophic
 Deceleration of head growth from early childhoodSleep disturbances, including night time screaming
 Regression followed by recovery of interactionInexplicable episodes of laughing or screaming
Apparently diminished pain sensitivity
Intense eye contact and/or eye pointing