Functional Movement Disorder 

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Functional Movement Disorder

Description

  • functional movement disorders characterized by abnormal, involuntary movements (including tremor, dystonia, myoclonus, tics, and/or abnormal gait and speech patterns) that are not caused by damage or structural disease of the nervous system(1,2,3)

Also Called

  • psychogenic movement disorder
  • motor functional neurological disorder
  • functional motor disorder
  • nonorganic movement disorder
  • FMD

Definitions

  • organic neurologic disorder – neurologic disease caused by an underlying physiologic pathology such as structural damage to the nervous system

Epidemiology

Who Is Most Affected

  • women; however, functional myoclonus and functional parkinsonism reported to occur with similar or greater frequency in men(1,3)
  • reported mean age of onset 40-50 years (Rev Neurol (Paris) 2020 May;176(4):244)

Incidence/Prevalence

Risk Factors

  • psychological stressors – may increase risk of or trigger onset of functional movement disorder but are no longer considered causative or necessary for diagnosis(1,2,3)
  • family history of similar functional disorders or chronic neurologic disorders(3)
  • risk factors for functional neurologic disorders include
    • female sex
    • coexisting health problems, including neurologic disease with physiologic pathology
    • difficulties in interpersonal relationships
    • traumatic life events, including childhood abuse
    • exposure to movement disorders (functional or with physiologic pathology) in friends or family
    • Reference – Handb Clin Neurol 2016;139:47
  • physical injury, infection, drug reaction, and pain exacerbation reported to precede onset of functional symptoms in approximately 80% of patients with functional movement disorder (Neurobiol Dis 2019 Jul;127:32)
  • several measures of childhood trauma may be associated with functional movement disorder in adults
    •  based on case-control study
    • 64 adults with functional movement disorder (mean age 45 years, 72% women) were compared to 39 adults with focal hand dystonia (mean age 48 years, 74% women) and 39 healthy volunteers (mean age 48 years, 74% women)
      • adults excluded if major current psychiatric disorder or history of neurologic disorder or traumatic brain injury
      • all adults had psychological evaluations and completed several assessments of childhood stressors, including
        • Trauma Life Events Questionnaire (TLEQ) assessing how many of several different types of events ever experienced (total score range 0-23); if fear, helplessness, and/or horror associated with the event (0-23); and total number of events of any type (0-115) (with higher scores indicating worse trauma)
        • Childhood Trauma Questionnaire (CTQ, each subscale total score range 5-25 points, with higher scores indicating greater childhood abuse/neglect)
    • statistical analyses adjusted for depression score
    • comparing mean scores for functional movement disorder vs. focal hand dystonia vs. healthy volunteers
      • event fear TLEQ score 3.1 vs. 1.6 vs. 1.4 (p = 0.02)
      • total number of traumatic events on TLEQ 13.4 vs. 7.6 vs. 6.9 (p = 0.04)
      • emotional abuse CTQ score 10.4 vs. 7.5 vs. 6.9 (p = 0.007)
      • physical neglect CTQ score 11.8 vs. 6.6 vs. 8.2 (p < 0.0001)
    • no significant differences in TLEQ number of different types of events ever experienced and CTQ physical abuse, sexual abuse, emotional neglect, and minimization/denial subscales
    • Reference – Mov Disord 2011 Aug 15;26(10):1844full-text
    • similar results reported in systematic review of 34 case-control studies evaluating association of stressors with any functional neurologic symptom disorder (including nonepileptic seizures, functional movement disorders, or functional sensory disorder) in 1,405 persons (Lancet Psychiatry 2018 Apr;5(4):307)

Associated Conditions

  • anxiety and depression(3)
  • functional neurologic disorder associated with
    • comorbid neurologic disorder with physiologic pathology (reported in about 10% of cases)
    • increased risk of other symptoms, including pain, fatigue, and mixed functional weakness and sensory disorder
    • Reference – Handb Clin Neurol 2016;139:47
  • one-third of patients with idiopathic Parkinson disease reported onset of functional neurologic symptoms before or in tandem with onset of Parkinson disease in retrospective cohort of 106 adults (J Neurol Neurosurg Psychiatry 2018 Jun;89(6):566)

Etiology and Pathogenesis

Causes

  • cause of functional movement disorder has not been identified, but genetic, biological, environmental, and psychological factors are thought to contribute to onset and perpetuation(1,2)

Pathogenesis

  • precise pathogenesis for functional movement disorder not known; proposed mechanisms based on limited evidence(1,3)
  • proposed mechanisms related to psychological and brain imaging findings associated with functional movement disorder(1,3)
    • reduced sense of control over voluntary movements
      • may help explain why movements that appear to be generated through mechanisms associated with voluntary movements are perceived as involuntary
      • functional movement disorder associated with reduced connectivity on functional magnetic resonance imaging between
        • temporoparietal junction and sensorimotor areas
        • supplementary motor area and prefrontal cortex (which helps select and inhibit movements)
    • difficulty regulating attention, including abnormal body-focused attention leading to abnormal movements
    • increased influence of emotional states
      • increased activity of limbic areas in response to emotion-eliciting stimuli
      • increased connectivity between amygdala and motor preparatory systems during emotional arousal
      • reduced resting parasympathetic activity resulting in lower vagal tone and increased vulnerability to stressful events
    • difficulty identifying and describing one’s emotions
      • may help explain lack of self-reported association between stress and movement symptoms
      • functional movement disorder associated with reduced activation in sensory and motor areas in response to emotional stimuli
  • stressful events may increase risk of functional neurologic disorders (FNDs) but cannot by themselves account for the disorder(1)
    • lack of potentially pathogenic stressful events in many patients with FNDs
    • long latency between possible event and symptom onset
    • large variability of symptoms among patients with similar possible events
    • lack of a physiologic mechanism

History and Physical

Clinical Presentation

  • abnormal movement, muscle function, gait, and/or speech, usually variable in severity and characteristics, without apparent physiologic cause, such as(1,2)
    • tremor
    • slowness without fatigue
    • uncontrolled muscle contractions (dystonia)
    • gait abnormalities
    • difficulties standing and walking (astasia-abasia)
    • jerking movements
    • speech difficulties
  • clinical features raising suspicion of functional movement disorder include(1,3)
    • sudden onset
    • variability and inconsistency – changing patterns and characteristics such as in frequency, direction of movement, type of movement disorder, and affected body part
    • entrainability – involuntary movement that adopts the same frequency or a harmonic of the frequency of voluntary repetitive movements performed with an unaffected body part
    • suggestibility – increase or decrease of involuntary movement after a “suggestion” such as application of vibrating tuning fork or suggesting that different stimuli may alter movements
    • distractibility – decrease or cessation of movements when focusing on mental tasks or motor tasks with unaffected body parts, such as slowly tapping each finger on 1 hand in sequence
    • exacerbation with attention
    • overt demonstration of effort or excessive fatigue
    • spontaneous remission
    • characteristics that are inconsistent with characteristics of organic motor disorders with physiologic pathology
  • additional motor or sensory symptoms developing within mean 3 years reported in 48 of 100 patients with functional movement disorder in prospective cohort study (Front Neurol 2020;11:582215full-text)
  • comorbid organic neurologic disease with physiologic pathology reported in about 10% of cases of functional neurologic symptom disorder (Handb Clin Neurol 2016;139:47)
  • when taking history and performing physical, also look for(3)
    • la belle indifference, such as smiling and giggling even while describing severe impairment
    • convergence spasm (dysconjugate gaze with miosis) while fixating on near object
    • giveway weakness – display of full strength initially but associated with tremulousness and followed by sudden loss of power
    • effort and pain during strength testing
    • nonanatomic neurologic signs such as impaired sensation and strength in legs but normal reflexes
    • excessive slowness
    • startle response

History

History of Present Illness (HPI)

  • ask if the movement abnormalities first appeared suddenly or if they gradually developed(1,3)
  • ask if the symptoms
    • come and go (are episodic)(1,3)
    • fluctuate or change in characteristics (such as tremor frequency or severity of weakness)(1,3)
    • lessen with distraction, but be aware that patients may be reluctant to disclose distractibility of motor symptoms due to fears of not being taken seriously (Neurology 2012 Jul 17;79(3):282)
  • ask about alleviating and exacerbating factors(3)
  • obtain collateral information from family members or friends regarding their observations if possible(3)
  • if dystonia, ask about concomitant pain, which may be suggestive of functional disorder(1)

Past Medical History (PMH)

  • ask about any psychiatric conditions, especially anxiety or major depressive disorder, which may co-occur with functional movement disorder and require management(1)
  • ask about prior diagnosis of conversion disorder, psychogenic disorder, functional neurologic disorder, or psychogenic nonepileptic seizure, and assess patient understanding of diagnosis(1,2)
  • ask about possible precipitating factors prior to symptom onset, including injury, illness, or drug reaction (J Neurol Sci 2014 Mar 15;338(1-2):174)
  • ask about previous diagnoses and any surgical procedures(3)

Family History (FH)

Social History (SH)

  • ask about previous potential stressors such as physical trauma, medical illness, and psychosocial events (not necessary for diagnosis but may predispose some patients to developing functional movement disorder and/or trigger functional symptoms in some patients)(1,2)

Neurologic Exam

Functional Tremor

  • tremors are involuntary, rhythmic, oscillatory movements of a body part around 1 or more joints; see Tremor – Approach to the Patient for details on tremor in general
  • clinical features suggestive of functional tremor(1,3)
    • variability in tremor frequency, amplitude, body location, and/or direction, such as pronation/supination vs. flexion/extension
    • entrainment – tremor adopts frequency or harmonic of frequency of voluntary repetitive movement performed with less affected body part
    • full suppressibility – tremor ceases with externally cued rhythmic movement
    • persistence while at rest, when maintaining posture, and during kinetic movements
    • whole body tremor, including bobbing of head and trunk
    • whack-a-mole sign – emergence or worsening of tremor in another body part after the initially affected body part is suppressed
    • tonic coactivation of antagonistic muscles at onset
    • temporary disruption of tremor (pause or reduction in amplitude) during contralateral ballistic movement
    • dual task interference – difficulty with voluntary movements of unaffected limb while tremor occurring in affected limb

Functional Parkinsonism

  • typical signs and symptoms of parkinsonism include tremor at rest, rigidity, akinesia, and postural instability; see Parkinsonism for details on parkinsonism in general
  • clinical features suggestive of functional parkinsonism(1,3)
    • excessive slowness without decrement or fatigue
    • lack of speed or amplitude decrement on repetitive tapping (sequence effect)
    • variable resistance during passive manipulation (inconsistent rigidity)
    • normal speed for spontaneous movements
    • hand tremor
      • usually affects dominant hand
      • persists while at rest, maintaining posture, and performing kinetic movements
      • disappears when walking
    • effortful gait
    • exaggerated response to the pull test
    • may co-occur with Parkinson disease

Functional Tics

  • tics are involuntary movements that are similar to rapid voluntary movements (as opposed to tremors, dystonia, or myoclonus) (Neurology 2019 Oct 22;93(17):750)
  • clinical features suggestive of functional tics(1,3)
    • not completely stereotypical
    • interference with speech or other voluntary actions (“blocking tics”)
    • lack of premonitory urge/sensation
    • inability to voluntarily suppress tics

Functional Myoclonus

  • myoclonus is a “shock-like” movement caused by either sudden muscle contraction or muscle tone lapse; see Myoclonus – Approach to the Patient for details on myoclonus in general
  • clinical features suggestive of functional myoclonus(1,3)
    • “jerking” movements of limbs, head, or trunk that may be associated with facial grimacing and forceful eyelid closure
    • entrainment or full suppressibility (temporary improvement or cessation during externally cued movement)
    • variable duration, latency after stimulus (if stimulus-sensitive), or distribution of jerks
    • arrhythmic
    • occurs in episodes as opposed to randomly
    • does not persist during sleep
  • functional palatal myoclonus (rhythmic contraction of soft palate)(3)
    • has variable frequency and magnitude
    • can be entrainable
    • may be associated with involuntary head and face movements

Functional Gait and Posture Disorders

  • clinical features suggestive of functional gait disorder(1,3)
    • intermittent buckling of knees
    • lurching without falling
    • attraction to walls
    • dragging forefoot on ground
    • excessive demonstration of effort while walking (“huffing and puffing sign”)
    • excessive slowness
    • gait similar to walking on slippery surface
    • walking with arms outstretched (“tightrope walking”)
    • astasia-abasia – body contortions while tandem walking
    • no associated spasticity, neuropathy, or cerebellar dysfunction
  • functional gait disorder can occur in isolation but is most commonly seen in combination with other functional movement disorders(3)
  • clinical features suggestive of functional posture disorders(1,3)
    • may need assistance while standing
    • variability of postures
    • inconsistent and uneconomic posture
    • myoclonic jerks affecting the trunk
    • exaggerated response to pull test
  • clinical features indicative of functional balance disorders reported to include(1)
    • controlled falls or lack of falls despite excessive swaying during ambulation
    • reduction in balance deficits with dual tasks or distraction

Functional Speech Disorder

  • types of speech abnormalities include(1,3)
    • stuttering
    • speech arrests
    • effortful speech
    • foreign accent
    • hypophonia
    • dysphonia (alteration of voice quality/phonation)
  • clinical features suggestive of functional speech disorder(1,3)
    • sudden onset
    • episodic, with episodes lasting for minutes to days

Functional Stereotypy

  • stereotypies such as those seen in tardive dyskinesia are intermittent, uncontrolled, spontaneous, nonpurposeful movements such as
    • orofacial movements including chewing, lip smacking, tongue twisting and protrusion, and facial grimacing
    • flexion and extension of thighs
    • foot tapping
    • “piano playing” movements in fingers and toes
    • hand rubbing
    • repetitive rocking and body swaying
  • functional stereotypy may have features similar to tardive dyskinesia but without exposure to antipsychotic medications(3)
    • associated orolingual dyskinesia, limb and trunk stereotypies, and respiratory dyskinesia
    • sudden onset
    • prominent distractibility
    • spontaneous remissions

Functional Paroxysmal Dyskinesia

  • paroxysmal dyskinesia – recurrent attacks of abnormal movements (such as dystonia and/or chorea), often following a trigger, without loss of consciousness (Neurol Clin 2020 May;38(2):433, J Neurol Neurosurg Psychiatry 2019 Feb;90(2):227)
  • clinical features suggestive of functional paroxysmal dyskinesia(3)
    • variable duration and patterns
    • atypical triggers such as stress, alcohol, and loud noises
    • poor or no response to medications
    • other functional movement disorders in some patients

Diagnosis

Making the Diagnosis

Diagnostic Criteria

  • Diagnostic and Statistical Manual of Mental Disorders, 5th ed. (DSM-5) criteria for functional neurologic symptom disorder include
    • ≥ 1 symptom of altered voluntary motor or sensory function
    • clinical evidence of discordance between symptom(s) and recognized neurologic or medical conditions
    • clinically significant distress or impaired social, occupational, or other functioning that warrants medical evaluation
    • symptom(s) not better explained by other medical or mental disorder
    • Reference – Curr Pain Headache Rep 2017 Jun;21(6):29
  • DSM-5 criteria no longer require identification of precipitating stressors for diagnosis of functional neurologic symptom disorder(1)

Differential Diagnosis

  • recognized medical conditions with identified or presumed physiologic pathology, including
    • essential tremor and other types of tremor
    • Parkinson disease
    • parkinsonism
    • cervical dystonia
    • Wilson disease
    • multiple system atrophy
    • stiff person syndrome
    • multiple sclerosis
    • myasthenia gravis
    • other types of myoclonus
    • Huntington disease
    • spinocerebellar ataxia
    • levodopa-induced or paroxysmal dyskinesia(3)
    • neurologic deficits following stroke
  • factitious disorder or malingering (rare)(1)

Testing Overview

Imaging Studies

  • structural neuroimaging such as computed tomography and magnetic resonance imaging may be used to rule out organic neurologic disorders if diagnostic uncertainty regarding functional disorder
    • clinical exam typically sufficient
    • imaging may be useful to evaluate for physiologic pathology, especially considering that functional movement disorder may co-occur with organic neurologic disorders
    • Reference – Curr Neurol Neurosci Rep 2019 Feb 12;19(3):12full-text
  • if parkinsonian signs and symptoms, dopamine transporter single photon emission computed tomography (DAT-SPECT or DaTScan) can demonstrate absence of nigrostriatal denervation characteristic of neurodegenerative parkinsonism in patients with functional parkinsonism (Int Rev Neurobiol 2018;143:163)
  • if diaphragmatic myoclonus suspected, ultrasound may be used to document evidence of distractibility and entrainment (Curr Opin Neurol 2017 Aug;30(4):427PDF)

Electroencephalogram (EEG)

  • EEG methods may have limited utility in patients with infrequent movements due to time limitations (Neurophysiol Clin 2014 Oct;44(4):417)
  • functional myoclonus may demonstrate Bereitschaftspotential (BP) on EEG

Electromyography (EMG) and Accelerometry

Functional Tremor

  • EMG and accelerometry (quantifying tremor movements, frequency, and amplitude) can be used to look for muscle activation and movement characteristics associated with functional tremor (Curr Opin Neurol 2017 Aug;30(4):427PDF)
  • record limb demonstrating tremor and contralateral limb while
    • at rest
    • with limbs outstretched (with and without weight loading)
    • performing tapping tasks (at 1, 3, and 5 hertz [Hz])
    • performing repetitive movements in response to external signals such as from a metronome
    • performing ballistic movements with less affected limb
    • Reference – Curr Opin Neurol 2017 Aug;30(4):427PDF
  • positive signs of functional tremor on EMG and/or accelerometry
    • frequency usually between 4 and 10 Hz
    • frequency varies spontaneously and during mental movement tasks
    • entrainment (tremor frequency changing to match another frequency or harmonic) during
      • contralateral limb rhythmic tasks
      • external rhythmic stimuli such as a metronome
    •  pause of tremor during contralateral rhythmic task or contralateral ballistic movement
    • tremor characteristics changing during mass loading
      • paradoxical increase in frequency and amplitude
      • direction of tremor such as from flexion/extension to pronation/supination
      • location of tremor (for example, from proximal to distal limb)
    • on EMG
      • coactivation of antagonist muscles (cocontraction) preceding tremor onset
      •  high interlimb EMG coherency during tremor
    • Reference – Neurophysiol Clin 2014 Oct;44(4):417
  • EMG and accelerometer test battery may help distinguish functional tremor from organic tremor (level 2 [mid-level] evidence)
    •  based on diagnostic case-control study
    • 38 patients with functional tremor (mean age 37 years) and 73 patients with organic tremor (mean age 55 years) were assessed with accelerometer and surface EMG
    • reference standard was standardized clinical diagnosis including evaluation of tremor entrainment and suppressibility
    • patients performed electrophysiologic test battery; results analyzed by outcome assessor blinded to standardized clinical diagnosis who assigned up to 3 points for each test (for maximum total score of 10 points)
      • increase in total power > 130% after weight loading (1 point)
      • pause or decrease in amplitude ≥ 50% of tremor during contralateral ballistic movement in ≥ 7 of 10 trials (1 point)
      • in patients with bilateral tremor, significant coherence between both affected arms (based on analysis of power spectra and coherence plots from EMG) (1 point)
      • tonic coactivation at tremor onset (tonic discharge of antagonist muscles on EMG about 300 milliseconds before onset of tremor on accelerometry) (1 point)
      • tests with less affected hand tapping at 1, 3, and 5 Hz while more tremulous hand at position of maximal tremor
        • abnormal tapping with less affected hand (1 point each for tapping ± 0.5 Hz outside target frequency)
        • tremor entrainment, suppression, or pathologic frequency shift of more tremulous hand (1 point for each target frequency)
    • mean total test battery score 3.6 points for functional tremor group vs. 1 point for organic tremor group (p < 0.001)
    • diagnostic performance of electrophysiologic test battery with total score ≥ 3 points indicating functional tremor
      • sensitivity 89.5%
      • specificity 95.9%
    • Reference – Mov Disord 2016 Apr;31(4):555

Functional Myoclonus

  • associated EMG findings include(3)
    • burst muscle contraction > 70 milliseconds
    • triphasic wave (demonstrating agonist and antagonist muscle activations)
    • variable reflex latency in response to sounds, pinprick, or tendon tap, usually > 100 milliseconds
  • EMG may be combined with electroencephalogram to document Bereitschaftspotential (BP); BP seen in voluntary movements and associated with negative cortical potential and maximal amplitude over central areas starting 1,000-2,000 milliseconds before jerk (Curr Opin Neurol 2017 Aug;30(4):427PDF)

Management

Management Overview

  • initial management of functional movement disorder involves careful explanation of diagnosis by experienced neurologist
    • give a clear and positive diagnosis (do not deny the patient a diagnosis by stating there is “no neurologic disease” or by emphasizing normal test results)
    • note that functional disorders are not merely a “diagnosis of exclusion,” but demonstrate the positive clinical features of the functional disorder, such as entrainment, that are incongruent with organic neurologic disease with physiologic pathology
    • emphasize potential reversibility of symptoms with treatment
    • focus on developing patient trust by demonstrating sincere belief in seriousness of symptoms and associated disability
    • avoid terminology such as psychogenic, hysteria, and stress-induced, which may carry negative connotations
  • evidence for specific treatment modalities is limited, but individualized and multidisciplinary treatment is common approach
    • psychotherapy, particularly cognitive behavioral therapy, might reduce symptom severity in adults with functional movement disorders
    • physical therapy suggested to help patients regain voluntary control through diverted attention techniques
    • medications not indicated for functional motor symptoms, but medical management of comorbid anxiety and depression may be considered

Patient Education and Explanation of Diagnosis

  • considerations when explaining diagnosis of functional movement disorder
    • demonstrate sincere belief in seriousness of symptoms and any associated disability
    • emphasize that there is an accepted diagnostic condition with some explanation for how the clinical features may manifest
      • give a clear and positive diagnosis (do not deny the patient a diagnosis by stating there is “no neurologic disease” or by emphasizing normal test results)
      • note that functional disorders are not merely a “diagnosis of exclusion” when no other explanation can be found
      • demonstrate positive clinical features of functional disorder, such as tremor entrainment, that are incongruent with organic neurologic disease
    • do not focus on identifying possible psychiatric comorbidity or stressors at outset, which can be discussed at later consultations; discuss possible mechanisms rather than speculating on possible etiologies
    • emphasize that treatment can potentially reduce symptoms; also offer referral and follow-up as appropriate (including for psychological or physical therapies, depending on the patient)
    • provide written information, such as clinic letter with individualized information and sources of further information (for example, www.neurosymptoms.org or www.FNDhope.org), to enhance recall and improve treatment adherence
    • Reference – Pract Neurol 2016 Feb;16(1):56
  • prior to initiating management, ensure patient understanding and acceptance of diagnosis(2)
    • assess patient’s readiness to change and motivation for therapy
    • establish treatment goals and expectations for functional and movement-specific outcomes
    • identify possible treatment barriers, including insufficient financial or psychosocial support

Cognitive Behavioral Therapy and Other Counseling

  • behavioral and psychological therapies for functional movement disorder has limited evidence; therapies being investigated include(2)
    • cognitive behavioral therapy (CBT) aiming to reduce cognitive distortions in order to improve emotions and behaviors
    • psychodynamic therapy focusing on interpersonal relationships and emotional processing
    • acceptance and commitment therapy focusing on mindfulness and psychological flexibility
    • mindfulness therapy
  • CBT might reduce symptom severity immediately after treatment in patients with functional movement disorder (level 2 [mid-level] evidence)
    •  based on quasi-randomized trial
    • 37 patients with functional movement disorder who had CBT, CBT plus physical activity, or standard care were assessed
      • 29 patients were randomized to either
        • CBT with 90-minute sessions once weekly for 12 weeks
        • CBT plus physical activity with 60-minute sessions twice weekly for 12 weeks
      • 8 patients receiving standard care were enrolled as control group; these patients were not randomized, and standard care was not described
    • 8 patients (27.6%) lost to follow-up (none from standard care group) and excluded from analysis
    • severity assessment
      • with Psychogenic Movement Disorders Rating Scale (PMDRS) (total score range 0-128 points, with higher scores indicating worse motor symptoms)
      • via video by outcome assessor blinded to aims of study, but unclear if blinded to allocated treatment
      • at baseline and posttreatment (12 weeks for both CBT groups; mean 9.2 weeks for standard care group)
    • comparing mean PMDRS score at baseline vs. posttreatment
      • 71.5 vs. 33.2 points with CBT alone (p < 0.001)
      • 76.7 vs. 38.8 points with CBT plus physical activity (p < 0.001)
      • 72.4 vs. 69.8 with standard care (not significant)
    • mean PMDRS score at posttreatment lower for each CBT group vs. standard care (p < 0.001); difference between CBT groups not significant
    • consistent results for motor severity and functional impairment PMDRS subscores, depression and anxiety scores, and quality-of-life score
    • Reference – Psychother Psychosom 2016;85(6):381
  • CBT for 12 weeks reported to reduce tremor severity in adults with functional tremor (level 3 [lacking direct] evidence)
    •  based on case series
    • 15 adults (mean age 50 years, 80% women) with unilateral functional tremor had 1-hour CBT sessions (including homework assignment) once weekly for 12 weeks
    • PMDRS used to assess tremor severity, duration, and incapacitation (total score range 0-128 points, with higher scores indicating worse tremor)
    • at end of CBT treatment
      • 60% had complete resolution of tremor
      • 13% had near-complete (> 75%) resolution of tremor
      • 13% had partial response (not defined)
      • mean PMDRS score reduced from 34.3 points at baseline to 7.4 points (p < 0.001)
    • compared to age ≥ 50 years, age < 50 years associated with greater improvement in tremor severity (mean PMDRS score 35.4 vs. 17.1, p = 0.05)
    • other baseline characteristics including symptom duration, anxiety scores, and depression scores not associated with PMDRS score change after CBT
    • Reference – Neurology 2019 Nov 5;93(19):e1787full-text, corrections can be found in Neurology 2020 Mar 10;94(10):459, Neurology 2020 Nov 10;95(19):890

Physical Therapy

  • physical therapy(2)
    • generally focuses on motor retraining to allow patients to regain voluntary control
    • also can address secondary injuries related to abnormal movements
  • consensus recommendations on physical therapy for functional movement disorder and related considerations
    • patients more likely to benefit from physical therapy for functional movement disorder if they
      • have an unambiguous diagnosis of functional movement disorder
      • have some confidence in and openness to the diagnosis of functional movement disorder
      • desire improvement and can identify treatment goals
    • physical therapy should be a part of a multidisciplinary approach
      • other components may include education, psychotherapy, occupational therapy, speech and language therapy, medication, and vocational rehabilitation
      • encourage open and consistent communication between multidisciplinary team and patient
    • when teaching patient about functional movement disorder, acknowledge that symptoms are real and are commonly seen and that movement can improve; see Patient Education and Explanation of Diagnosis for details
    • discuss how physical therapy “retrains” the nervous system to help regain control over movement
    • retraining can be partly accomplished by using diverted attention techniques to devise situations that increase the likelihood of generating normal movements
      • reducing self-focused attention may reduce cognitive control of movement (which may be more likely to be disordered) and stimulate “automatic” generation of movement (which may be less likely to be disordered)
      • general diverted attention techniques include
        • thinking about a different part of the movement
        • attempting unfamiliar or unpredictable movements
        • cognitive distraction such as with conversation, music, or mental tasks
      • diverted attention examples for specific functional movement disorders
        • if upper-limb tremor, have patient
          • perform ballistic or rhythmic movements with contralateral unaffected limb, during which tremor in affected limb should reduce, disappear, or “entrain” to match the rhythmic frequency
          • make the movement “voluntary” by actively doing the tremor, increasing the magnitude, reducing the frequency, and then slowing the movement to stillness
          • actively contract muscle for a few seconds
        • if lower-limb tremor, have patient
          • perform side-to-side or back-to-front weight shifts; when tremor has reduced, slow weight shifts to stillness
          • perform toe-tapping as a competing movement
          • change habitual postures related to symptoms, such as reducing forefoot weight-bearing
        • if fixed dystonia, have patient
          • change sitting and standing postures to promote good alignment
          • perform normalized movements such as sit-to-stand, transfer from bed to standing, and walking while focusing attention on an external stimulus rather than dystonic limb
        • if gait disturbance, have patient
          • change walking speeds (note that increasing speed may exacerbate disturbance in some patients)
          • walk by sliding feet forward and gradually progress toward normal walking
    • for functional myoclonus, which may not respond to motor retraining
      • identify premonitory symptoms or self-focused attention prior to jerk that can be addressed with redirected attention
      • address pain, muscle overactivity, or altered patterns of movement preceding jerks, if present
    • additional considerations for physical therapy
      • develop trust with patients before challenging them
      • create an expectation that movements will improve
      • involve family and carers with therapy
      • limit “hands-on” treatment by facilitating movement rather than providing physical support
      • encourage early weight-bearing
      • encourage independence and self-management
      • focus on improving function and “automatic” movements, such as walking, rather than impairments or activities that require large amounts of attention, such as strengthening exercises
      • discourage maladaptive movement patterns and postures
      • discourage adaptive equipment and mobility aids (unless they are necessary), especially if acute presentation
        • if necessary to ensure safety, introduce equipment with plan to wean usage and discuss potential harms associated with long-term reliance
        • if patient does not improve with other treatments, consider adaptive equipment to promote independence and improve quality of life
      • avoid splints and devices that immobilize joints
      • discourage unhelpful thoughts and behaviors
      • collaborate with patient to develop self-management and relapse-prevention plans
      • encourage use of diary to track goals, outcome measures, and activity plans
    • Reference – J Neurol Neurosurg Psychiatry 2015 Oct;86(10):1113full-text
  • physical therapy with additional educational or cognitive components might improve some aspects of quality of life in patients with functional movement disorder, but evidence is limited (level 2 [mid-level] evidence)
    • based on systematic review limited by clinical heterogeneity
    • systematic review of 4 randomized trials evaluating physical therapy in 188 patients with functional movement disorder
      • trials published before 2013 were not included
      • physical therapy included education-based physical therapy (including movement retraining and self-management plans) in 2 trials and combination physical therapy and cognitive behavioral therapy in 2 trials
      • also see evidence summary of 1 of the trials
    • all trials had ≥ 1 limitation including small size or inadequate or unclear randomization or blinding of outcome assessors
    • meta-analysis not conducted due to clinical heterogeneity in interventions and outcome measures
    • physical therapy was associated with improvements in some aspects of quality of life in all 4 studies
    • Reference – Neurologia (Engl Ed) 2023 Apr 27
  • 5-day inpatient physical therapy intervention may improve physical function in adults with functional movement disorder (level 2 [mid-level] evidence)
    •  based on randomized trial without blinding of outcome assessors
    • 60 adults (mean age 43 years, 72% women) with functional movement disorder for ≥ 6 months were randomized to 5-day inpatient physical therapy intervention vs. usual care
      • inpatient physical therapy intervention consisted of 8 sessions of 45-90 minutes over 5 consecutive days and included education on etiology of functional movement disorder, movement retraining with redirection of attention, and development of self-management plan
      • usual care involved referral to neurophysiotherapy service; specific regimen not standardized
      • exclusion criteria included clinically evident anxiety or depression and predominant pain or fatigue
    • outcome assessors not blinded to treatment allocation; patients and treating clinicians also not blinded to other group’s intervention
    • functional movement disorders included mixed movement disorder (in 40%), gait disorder (27%), weakness (12%), upper-limb tremor (10%), head tremor (5%), myoclonus (5%), and fixed dystonia (2%); mean symptom duration 5.9 years
    • outcome assessments included
      • 36-Item Short Form Health Survey (SF-36); each domain with total score range 0 (poor health) to 100 (good)
      • Berg Balance Scale; total score range 0 (poor balance) to 56 (good)
      • 10-meter timed walk
    • comparing inpatient physical therapy vs. usual care at 6 months
      • mean SF-36 physical function score 52 vs. 23 points (p < 0.001)
      • mean SF-36 physical role score 47 vs. 27 points (p = 0.037)
      • mean SF-36 social function score 57 vs. 37 points (p = 0.007)
      • mean 10-meter walk time 9.6 vs. 19 seconds (p = 0.001)
      • mean Berg Balance Scale score 48 vs. 37 points (p = 0.003)
      • “improved” or “much improved” on Clinical Global Impression Scale in 72% vs. 18% (no p value reported)
    • Reference – J Neurol Neurosurg Psychiatry 2017 Jun;88(6):484
  • physical therapy may reduce motor symptoms in patients with functional movement disorder (level 2 [mid-level] evidence)
    • based on systematic review of mostly observational studies
    • systematic review of 29 studies (1 retrospective cohort study and 28 case series) evaluating physical therapy in 373 patients (mean age 40 years, 70% women) with functional movement disorder
      • common treatment principles included behavior shaping with positive reinforcement while ignoring maladaptive patterns, effective interdisciplinary communication, agreed-upon treatment contract, allowance for face-saving, and family involvement in rehabilitation
      • physical therapy interventions varied across studies, most frequently involving motor learning and behavioral approaches in multidisciplinary context
    • all studies reported some improvement in motor symptoms immediately following treatment; higher prevalence in studies with larger sample sizes
    • 20 studies with 251 patients reported improvement beyond treatment duration (follow-up ranging from 10 months to 7 years)
    • 12 studies with 51 children and adolescents (age range 7-18 years) reported complete recovery in 80%, partial recovery in 16%, and no change in 4% at completion of treatment with physical therapy intervention
    • 1 retrospective cohort study with 60 patients who received physical and occupational therapy reported a good outcome (defined as marked improvement or remission) in 68.8% on self-reported global impression scale immediately following therapy and 60.4% at mean follow-up of 2 years
    • Reference – J Psychosom Res 2013 Aug;75(2):93

Medications

  • medications may be considered to reduce comorbid anxiety, depression, or pain based on clinical judgment(2)
  • antidepressants alone have not been shown to reduce movement-related symptoms, but evidence is limited(2)
  • if patient currently taking medication to directly address movement-related symptoms(2)
    • begin tapering any medications not indicated for functional movement disorder such as carbidopa/levodopa or antiseizure medications
    • may be helpful to delay taper until after initiation of other treatment modalities and patient has developed strategies to cope with motor symptoms
  • botulinum neurotoxin (BoNT) type A injections do not appear to reduce motor symptoms in adults with functional myoclonus or tremor (level 2 [mid-level] evidence)
    •  based on small randomized trial
    • 48 adults (median age about 52 years, 42% women) with severe functional myoclonus or tremor were randomized to BoNT type A injections vs. placebo at baseline and 3 months and were assessed at 4 months
      • all patients completed electromyography assessments to support diagnosis of functional movement disorder and select muscles for BoNT injections
      • specific injection regimens based on patient; median BoNT dose 240 units at baseline and 440 units at 3 months
      • trial protocol amendment extended inclusion criteria to patients with functional tremor to improve recruitment
    • comparing BoNT vs. placebo at 4 months
      • 64% vs. 56.5% had clinician-rated improvement on Clinical Global Impression-Improvement Scale (not significant)
      • no significant differences in any other measure of symptom severity or clinical improvement by either patients or clinicians
    • adverse events
      • serious adverse events in 2 patients: 1 with BoNT who needed ketamine for chronic pain and 1 with placebo who had cardiac syncope
      • pain at injection site in 36% with BoNT injection and 8.7% with placebo (no p value reported)
      • 3 patients discontinued BoNT due to worsening symptoms or pain
    • Reference – J Neurol Neurosurg Psychiatry 2019 Nov;90(11):1244full-text

Consultation and Referral

  • diagnosing neurologist should consider
    • follow-up visits to continue discussing and reinforcing diagnosis, monitor treatment, and address treatment barriers and/or new symptoms (Pract Neurol 2016 Feb;16(1):56)
    • referral to physical therapist for motor retraining and, if indicated, management of deconditioning and/or injuries secondary to functional movement disorder(2)
    •  referral to psychological therapy and/or other specialists (Pract Neurol 2016 Feb;16(1):56)
  • for long-term care of patients with functional movement disorders
    • optimal care may involve individualized management by multidisciplinary team that includes a neurologist, psychologist, psychiatrist, physical therapist, occupational therapist, speech therapist, and/or social worker (Parkinsonism Relat Disord 2018 Jan;46 Suppl 1:S80full-text)
    • unclear if neurologists or psychiatrists/psychologists should play primary role
      • arguments in favor of neurologists having primary role include
        • importance of neurologic features in diagnosing disorder and assessing improvement
        • improved patient acceptance of diagnosis and treatment compliance, particularly in patients who deny psychiatric diagnosis
        • identification of perpetuating factors, such as maladaptive avoidance maneuvers, during neurologic follow-up visits
        • ability to assess any new neurologic symptoms that subsequently develop and to discern if new symptoms are related to functional neurologic disorder or organic condition
        • assessing treatment response and addressing treatment barriers
      • arguments in favor of psychiatrists/psychologists having primary role include
        • use of Diagnostic and Statistical Manual of Mental Disorders, 5th ed. to define disorder
        • lack of neurologic etiology (although neuroimaging abnormalities are observed in some patients, similar abnormalities can be found in patients with psychiatric conditions such as major depression or posttraumatic stress disorder)
        • importance of psychiatric treatments such as cognitive behavioral therapy that are time-intensive and in which neurologists are not trained
      • Reference – Neurol Clin Pract 2019 Apr;9(2):165full-text

Other Management

  • occupational therapy (OT)(2)
    • OT aims to increase functional ability to perform activities related to daily living, work, and leisure
    • treatment may focus on relearning normal movement patterns and suppressing abnormal movements
    • no randomized trials specifically evaluating OT for functional movement disorders have been reported
    • OT often a part of multidisciplinary management strategies
  • transcranial magnetic stimulation (TMS)
    • has been studied in patients with functional movement disorders, but evidence suggests efficacy may be driven primarily by a behavioral or placebo response rather than neuromodulatory changes(2)
    •  TMS may not meaningfully improve motor symptoms in adults with functional tremor (level 2 [mid-level] evidence)
      •  based on small randomized trial
      • 18 adults (mean age 49 years, 55% women) with functional tremor were randomized to repetitive TMS (rTMS) at 1 hertz (Hz) vs. sham stimulation once daily for 5 consecutive days
      • severity of functional tremor assessed by 3 neurologists blinded to group allocation using
        • Psychogenic Movement Disorders Rating Scale (PMDRS) (total score range 0-128 points, with higher scores indicating worse motor symptoms)
        • Clinical Global Impression Severity Scale (CGI-S) (total score range 1-7 points, with higher scores indicating greater severity)
      • all patients completed 12-month follow-up; 1 patient in rTMS group excluded from final analysis after abnormal dopamine transporter scan (DaTscan), suggesting physiologic pathology as cause of movement symptoms
      • mean PMDRS score at baseline 29 points
      • comparing rTMS vs. sham at 1 month
        • mean improvement in PMDRS score 11.7 vs. 4.9 points (no p value reported; improvement from baseline significant with rTMS but not sham group); difference may not be clinically meaningful
        • mean PMDRS score 17.7 vs. 23.3 points (no p value reported)
        • mean CGI-S score 3.2 vs. 3.6 points (no p value reported)
      • Reference – Mov Disord 2019 Aug;34(8):1210
    • lower-frequency repetitive TMS may not reduce motor symptoms compared to spinal root magnetic stimulation (RMS) in adults with functional movement disorders (level 2 [mid-level] evidence)
      •  based on randomized crossover trial without assessment of statistical power
      • 33 adults (median age 45 years, 82% women) with functional movement disorder for median 2.9 years were randomized to repetitive TMS vs. RMS for 1 session and then crossed over to other treatment on following day (≥ 18 hours later)
        • low-frequency (0.25 Hz) TMS targeted cortex contralateral to motor symptoms, and RMS targeted spinal roots homolateral to symptoms
        • patients were video recorded at baseline, after first stimulation, and after second stimulation; a clinician blinded to treatment allocation graded patient’s motor symptoms on scale of 7 (normal) to 41 (severe) points
      • statistical power assessment to explain sample size and methodology not conducted
      • functional movement disorders included tremor (in 39%), dystonia (33%), mixed myoclonus and dystonia (12%), myoclonus (6%), stereotypies (6%), and parkinsonism (3%); 60.6% of adults had comorbid anxiety disorder
      • median improvement after first session 37.5% with TMS as first session and 23.6% with RMS as first session (not significant)
      • consistent results when stimulation type assessed with multifactorial analysis of variance over both sessions
      • Reference – Front Neurol 2017;8:338full-text
      • CLINICIANS’ PRACTICE POINT: The authors suggest that the lack of significant differences in symptom improvement between TMS and RMS indicate that any benefit of TMS procedures are not through cortical neuromodulation but may be due to the placebo effect.

Complications

  • functional movement disorders associated with substantial symptom burden and physical disability (Handb Clin Neurol 2016;139:47)
  • functional movement disorders have similar severity to that experienced by patients with neurologic disorders with physiologic pathology (Handb Clin Neurol 2016;139:47)

Prognosis

  • same or worse outcome reported by about 40% of patients with functional movement disorder, complete remission in about 20%, and some improvement in about 40% at mean 7.4-year follow-up (Handb Clin Neurol 2016;139:523)
  • there is hope that improved recognition of functional movement disorders can promote earlier diagnosis and increased access to treatment, potentially leading to improved prognosis(2)
  • short symptom duration, early diagnosis, and patient confidence in care appear associated with more favorable prognosis in adults with functional movement disorders
    • based on systematic review of mostly observational studies
    • systematic review of 24 studies evaluating prognostic factors in 1,134 adults with functional movement disorders and followed for mean 7.4 years
    • studies varied in size (range 8-517 adults), duration of follow-up (range 0.5-19 years), completeness of follow-up (range 14%-100%), movement disorder, and symptom outcome (range 10%-90% better to complete recovery at follow-up)
    • > 33% had same or worse symptoms at follow-up in analysis of 15 studies with 668 adults (weighted by number of included adults)
    • 21.5% had complete remission at follow-up in analysis of 15 studies with 559 adults
    • prognostic factors investigated varied across studies, including age, IQ, educational status, marital status, comorbid anxiety and depression, and pending litigation
    • factors associated with more favorable prognosis
      • shorter duration of symptoms in analysis of 9 studies with 451 adults
      • early diagnosis in analysis of 8 studies with 879 adults
      • patient confidence in clinician and care in analysis of 2 studies with 728 adults
    • presence of personality disorder associated with unfavorable prognosis in analysis of 3 studies with 442 adults
    • pooled frequency of symptoms staying the same or worsening over time
      • tremor in 44%-90% in analysis of 5 studies with 191 adults
      • dystonia in 73%-83% in analysis of 2 studies with 103 adults
      • weakness or paralysis in 4%-69% in analysis of 5 studies with 25-60 adults
    • Reference – J Neurol Neurosurg Psychiatry 2014 Feb;85(2):220

Prevention and Screening

  • not applicable

Guidelines and Resources

Guidelines

United Kingdom Guidelines

Review Articles

General Reviews

Phenotype-specific Reviews

  • to search MEDLINE for (Functional Movement Disorder) with targeted search (Clinical Queries), click therapy, diagnosis, or prognosis

Patient Information

  • handout on functional neurological disorder from Patient UK
  • handout on tremors (shaking) from Patient UK

References

General References Used

The references listed below are used in this DynaMed topic primarily to support background information and for guidance where evidence summaries are not felt to be necessary. Most references are incorporated within the text along with the evidence summaries.

  1. Espay AJ, Aybek S, Carson A, et al. Current Concepts in Diagnosis and Treatment of Functional Neurological Disorders. JAMA Neurol. 2018 Sep 1;75(9):1132-1141full-text.
  2. LaFaver K. Treatment of Functional Movement Disorders. Neurol Clin. 2020 May;38(2):469-480.
  3. Thenganatt MA, Jankovic J. Psychogenic (Functional) Movement Disorders. Continuum (Minneap Minn). 2019 Aug;25(4):1121-1140.

 

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