Table 2 The 28-feature definition proposed by the Regression Working Group of the Down Syndrome Medical Interest Group: unexplained regression in Down syndrome (URDS) compared with age-matched controls with Down syndrome
From: Unexplained regression in Down syndrome: 35 cases from an international Down syndrome database
All | Medical evaluation negative | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
URDS (N = 35) | Control (N = 35) | p valuea | URDS (N = 11) | Control (N = 11) | p valuea | |||||
N | % | N | % | N | % | N | % | |||
Core feature (…with an onset of three months or greater) | ||||||||||
Adaptive function | ||||||||||
Social skills: withdrawal, avoidance, isolation; time spent alone | 33 | 94% | 1 | 3% | <0.001 | 10 | 91% | 1 | 9% | 0.004 |
Functional ADLs: loss of acquired skills; dependent | 31 | 91% | 1 | 3% | <0.001 | 11 | 100% | 1 | 9% | 0.002 |
Speech: reduced, infrequent; whisper, monosyllabic, or mute | 31 | 89% | 2 | 6% | <0.001 | 10 | 91% | 1 | 9% | 0.004 |
Cognitive–executive function | ||||||||||
Attention: atypical, odd; gaze aversion, poor eye contact, or impaired ocular control | 32 | 91% | 1 | 3% | <0.001 | 9 | 82% | 1 | 9% | 0.008 |
Functional skills: loss, confused, disorganized; unable to function at school/job | 30 | 86% | 0 | 0% | <0.001 | 11 | 100% | 0 | 0% | <0.001 |
Procedural memory: less able to perform or performs with assistance needed, with regard to ADL routines or favorite activities | 30 | 86% | 1 | 3% | <0.001 | 11 | 100% | 1 | 9% | 0.002 |
Learning memory: diminished working memory; not processing or learning | 28 | 80% | 0 | 0% | <0.001 | 10 | 91% | 0 | 0% | 0.002 |
Planning, organizing: not goal directed, disorganized | 27 | 77% | 0 | 0% | <0.001 | 10 | 91% | 0 | 0% | 0.002 |
Declarative memory: forgetful and confused with regard to people, places, and events | 20 | 59% | 0 | 0% | <0.001 | 8 | 73% | 0 | 0% | 0.008 |
Motor control | ||||||||||
Initiation–motivation: abulia, avolition, mutism | 28 | 80% | 0 | 0% | <0.001 | 9 | 82% | 0 | 0% | 0.004 |
Stereotyped movements: tics, stereotypies | 20 | 57% | 0 | 0% | <0.001 | 9 | 82% | 0 | 0% | 0.004 |
Catatonia | 19 | 56% | 0 | 0% | <0.001 | 5 | 45% | 0 | 0% | 0.063 |
Extrapyramidal: bradykinesia, freezing, cogwheel rigidity, tremor | 17 | 50% | 0 | 0% | <0.001 | 4 | 36% | 0 | 0% | 0.125 |
Common feature | ||||||||||
Behavior | ||||||||||
Internalizing: apathy, withdrawal, mood, stereotype, SIB | 32 | 91% | 1 | 3% | <0.001 | 9 | 82% | 0 | 0% | 0.004 |
Externalizing: hyperactivity, irritable, disruptive, agitated | 15 | 43% | 5 | 14% | 0.031 | 5 | 45% | 2 | 18% | 0.375 |
Mental health | ||||||||||
Mood, emotion, self-regulation: depression, compulsions, psychosis, PTSD, anxiety, panic, ASD/DSDD | 31 | 89% | 3 | 9% | <0.001 | 9 | 82% | 0 | 0% | 0.004 |
Sleep disturbance: Insomnia, circadian shift | 26 | 74% | 3 | 9% | <0.001 | 9 | 82% | 1 | 9% | 0.021 |
Transition/change causing emotional distress in past 1 year | 17 | 50% | 4 | 11% | <0.001 | 5 | 50% | 1 | 9% | 0.063 |
Appetite: anorexia, weight loss | 17 | 50% | 0 | 0% | <0.001 | 5 | 50% | 0 | 0% | 0.063 |
Incontinence: urine, feces | 12 | 35% | 1 | 3% | 0.003 | 5 | 45% | 0 | 0% | 0.063 |
Trauma/loss/grief, causing emotional distress in past 1 year | 10 | 29% | 3 | 9% | 0.065 | 2 | 18% | 0 | 0% | 0.500 |
Puberty, causing emotional distress in past 1 year | 8 | 23% | 1 | 3% | 0.039 | 3 | 27% | 0 | 0% | 0.250 |
Illness/hospitalization, causing emotional distress in past 1 year | 8 | 23% | 1 | 3% | 0.039 | 4 | 36% | 0 | 0% | 0.125 |
Sleep apnea, seizures: evidence on PSG, EEG | 5 | 15% | 10 | 29% | 0.388 | 1 | 10% | 3 | 27% | >0.99 |
Other inflammatory, autoimmune condition | 5 | 14% | 3 | 9% | 0.727 | 2 | 18% | 0 | 0% | 0.500 |
Systemic illness: pain, surgery | 5 | 14% | 2 | 6% | 0.625 | 2 | 18% | 1 | 10% | N/A |
Autonomic: syncope, pallor, sweating | 2 | 6% | 1 | 3% | >0.99 | 0 | 0% | 0 | 0% | – |
Vision, hearing: acute loss or deterioration | 1 | 3% | 1 | 3% | >0.99 | 0 | 0% | 0 | 0% | – |
