ALGORITHM​
1. PERIODS OF RESOLUTION AND RECURRENCE ?
YES: LOOK AT SPECIFIC FEATURES ON EXAM [LINK]
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NO: STEP 2
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2. ABRUPT ONSET
YES: LOOK AT SPECIFIC FEATURES ON EXAM [LINK]
NO: STEP 3
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3.RISK SCORE # > =3
YES: LOOK AT SPECIFIC FEATURES ON EXAM [LINK]
NO: LESS LIKELY FUNCTIONAL; LOOK AT OTHER GENERAL FEATURES GIVEN BELOW %
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RISK SCORE CALCULATION #
E (Suspected FD) =
2.5 x [Presence of a comorbid FSD @ ] +
1.5 x [On or pursuing disability benefits] +
1.5 x [Presence of cognitive symptoms ] +
1.5 x [Lifetime history of mood or anxiety disorder].
Cut off score of ≥3 (indicating the presence of two or more risk score factors), has a cumulative total sensitivity of 88.9% for FD.
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Comorbid functional somatic disorder (FSD) @
Fibromyalgia
CRPS type 1
Irritable bowel syndrome [IBS]
Chronic fatigue syndrome (30%)
Autonomic symptoms
Gastroparesis (10%)
POTS (7%)
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Cognitive complaints
Can be seen in 25% patients
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Atypical sensory tricks
Stroking and flexing an arm, leading to rapid resolution and sometimes resulting in the abnormal posture transferring to the opposite limb, touching a side of the face causing facial spasm to move to the other side, head shaking suddenly halting
blepharospasm, and facial spasms and lip pulling completely resolving with speech but also resolving when closing the mouth.
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GENERAL FEATURES. %
Pain at presentation
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Physical precipitating event
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No family history of movement disorders
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≥3 medication class allergies meeting criteria for multiple drug intolerance syndrome
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Dystonia at rest at onset
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Onset of paroxysmal dystonia in adulthood > 20yrs
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Movement not patterned and is inconsistent and incongruent with other forms of dystonia
Multiple different and varying semiologies
Foot dystonia in an adult
Dystonia at rest at onset
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Lack of overflow dystonia
Reduced or absent co-contraction of antagonistic muscles compared to other forms of dystonia
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Distractibility
Atypical sensory tricks eg. improvement with tuning fork.
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Immediate response to botulinum toxin injections
Functional neurological signs like give-way weakness, midline-splitting sensory loss
“Whack-a-mole” sign, where moving out of one abnormal posture can result in spread to the contralateral side or into another abnormal posture
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Fixed neck postures in early stages
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