Download PDF
Semin Neurol 2023; 43(01): 106-122
DOI: 10.1055/s-0043-1763505
Review Article

Moving Beyond Movement: Diagnosing Functional Movement Disorder

Gabriela S. Gilmour
1   Edmond J. Safra Program in Parkinson's Disease and the Morton and Gloria Shulman Movement Disorders Clinic, University Health Network, Toronto, Ontario, Canada
,
Sarah C. Lidstone 
1   Edmond J. Safra Program in Parkinson's Disease and the Morton and Gloria Shulman Movement Disorders Clinic, University Health Network, Toronto, Ontario, Canada
2   Integrated Movement Disorders Program, Toronto Rehabilitation Institute, University Health Network, Toronto, Ontario, Canada
3   KITE Research Institute, Toronto Rehabilitation Institute, University Health Network, Toronto, Canada
› Author Affiliations Funding This work was supported by an anonymous donation to the Toronto Western Hospital Movement Disorders Clinic.
› Further Information
    Permissions and Reprints

Abstract

Functional movement disorder (FMD) is a complex neuropsychiatric syndrome, encompassing abnormal movements and weakness, and is a common cause of potentially disabling neurological symptoms. It is vital to recognize that FMD is a syndrome, with nonmotor manifestations negatively affecting a patient's quality of life. This review highlights a diagnostic algorithm, where a history suggestive of FMD is combined with the presence of positive signs on examination and appropriate investigations to make the diagnosis. Positive signs indicate internal inconsistency such as variability and distractibility, and clinical findings that are incongruent with other known neurological disease. Importantly, the clinical assessment acts as the first opportunity to allow patients to understand FMD as the cause for their symptoms. Accurate and early diagnosis of FMD is necessary given that it is a treatable and potentially reversible cause of disability, with significant risk of iatrogenic harm associated with misdiagnosis.

Keywords

functional neurological disorder - functional movement disorder - diagnosis - pathophysiology - positive signs

Note

This manuscript complies with all instructions to authors.


This manuscript is an original work and has not been published elsewhere and is not under consideration by another journal. This article does not contain clinical studies or patient data.


Ethical Standards

This article does not contain clinical studies or patient data.


Author Contributions

G.S.G.: Conceptualization; investigation; writing—original draft. S.C.L.: Conceptualization; writing—review and editing.




Publication History

Article published online:
09 March 2023

© 2023. Thieme. All rights reserved.

Thieme Medical Publishers, Inc.
333 Seventh Avenue, 18th Floor, New York, NY 10001, USA

 

  • References

  • 1 Lidstone SC, Costa-Parke M, Robinson EJ, Ercoli T, Stone J. FMD GAP Study Group. Functional movement disorder gender, age and phenotype study: a systematic review and individual patient meta-analysis of 4905 cases. J Neurol Neurosurg Psychiatry 2022; 93 (06) 609-616
    CrossrefPubMedGoogle Scholar
  • 2 Hallett M. Psychogenic movement disorders: a crisis for neurology. Curr Neurol Neurosci Rep 2006; 6 (04) 269-271
    CrossrefPubMedGoogle Scholar
  • 3 Gilmour GS, Nielsen G, Teodoro T. et al. Management of functional neurological disorder. J Neurol 2020; 267 (07) 2164-2172
    CrossrefPubMedGoogle Scholar
  • 4 Goldstein LH, Mellers JDC. Psychologic treatment of functional neurologic disorders. Handb Clin Neurol 2016; 139: 571-583
    CrossrefPubMedGoogle Scholar
  • 5 Nielsen G. Physical treatment of functional neurologic disorders. In: Hallett M, Stone J, Carson A. eds. Functional Neurologic Disorders. Vol 139. Amsterdam: Elsevier; 2016: 555-569
    CrossrefGoogle Scholar
  • 6 Nielsen G, Stone J, Matthews A. et al. Physiotherapy for functional motor disorders: a consensus recommendation. J Neurol Neurosurg Psychiatry 2015; 86 (10) 1113-1119
    CrossrefPubMedGoogle Scholar
  • 7 Nicholson C, Edwards MJ, Carson AJ. et al. Occupational therapy consensus recommendations for functional neurological disorder. J Neurol Neurosurg Psychiatry 2020; 91 (10) 1037-1045
    CrossrefPubMedGoogle Scholar
  • 8 Baker J, Barnett C, Cavalli L. et al. Management of functional communication, swallowing, cough and related disorders: consensus recommendations for speech and language therapy. J Neurol Neurosurg Psychiatry 2021; 92 (10) 1112-1125
    CrossrefPubMedGoogle Scholar
  • 9 Butler M, Shipston-Sharman O, Seynaeve M. et al. International online survey of 1048 individuals with functional neurological disorder. Eur J Neurol 2021; 28 (11) 3591-3602
    CrossrefPubMedGoogle Scholar
  • 10 Forejtová Z, Serranová T, Sieger T. et al. The complex syndrome of functional neurological disorder. Psychol Med 2022; 7: 1-11
    CrossrefPubMedGoogle Scholar
  • 11 Aybek S, Lidstone SC, Nielsen G. et al. What is the role of a specialist assessment clinic for FND? Lessons from three national referral centers. J Neuropsychiatry Clin Neurosci 2020; 32 (01) 79-84
    CrossrefPubMedGoogle Scholar
  • 12 Tinazzi M, Morgante F, Marcuzzo E. et al. Clinical correlates of functional motor disorders: an Italian multicenter study. Mov Disord Clin Pract (Hoboken) 2020; 7 (08) 920-929
    CrossrefPubMedGoogle Scholar
  • 13 Věchetová G, Slovák M, Kemlink D. et al. The impact of non-motor symptoms on the health-related quality of life in patients with functional movement disorders. J Psychosom Res 2018; 115 (September): 32-37
    CrossrefPubMedGoogle Scholar
  • 14 Tinazzi M, Geroin C, Marcuzzo E. et al. Functional motor phenotypes: to lump or to split?. J Neurol 2021; 268 (12) 4737-4743
    CrossrefPubMedGoogle Scholar
  • 15 Carson A, Lehn A. Epidemiology. Handb Clin Neurol 2016; 139: 47-60
    CrossrefPubMedGoogle Scholar
  • 16 Carson AJ, Ringbauer B, Stone J, McKenzie L, Warlow C, Sharpe M. Do medically unexplained symptoms matter? A prospective cohort study of 300 new referrals to neurology outpatient clinics. J Neurol Neurosurg Psychiatry 2000; 68 (02) 207-210
    CrossrefPubMedGoogle Scholar
  • 17 Popkirov S, Nicholson TR, Bloem BR. et al. Hiding in plain sight: functional neurological disorders in the news. J Neuropsychiatry Clin Neurosci 2019; 31 (04) 361-367
    CrossrefPubMedGoogle Scholar
  • 18 Stone J, Warlow C, Sharpe M. The symptom of functional weakness: a controlled study of 107 patients. Brain 2010; 133 (Pt 5): 1537-1551
    CrossrefPubMedGoogle Scholar
  • 19 Binzer M, Andersen PM, Kullgren G. Clinical characteristics of patients with motor disability due to conversion disorder: a prospective control group study. J Neurol Neurosurg Psychiatry 1997; 63 (01) 83-88
    CrossrefPubMedGoogle Scholar
  • 20 Stefánsson JG, Messina JA, Meyerowitz S. Hysterical neurosis, conversion type: clinical and epidemiological considerations. Acta Psychiatr Scand 1976; 53 (02) 119-138
    CrossrefPubMedGoogle Scholar
  • 21 Stevens DL. Neurology in Gloucestershire: the clinical workload of an English neurologist. J Neurol Neurosurg Psychiatry 1989; 52 (04) 439-446
    CrossrefPubMedGoogle Scholar
  • 22 Stone J, Carson A, Duncan R. et al. Who is referred to neurology clinics?–the diagnoses made in 3781 new patients. Clin Neurol Neurosurg 2010; 112 (09) 747-751
    CrossrefPubMedGoogle Scholar
  • 23 Stone J, Carson A, Duncan R. et al. Symptoms ‘unexplained by organic disease’ in 1144 new neurology out-patients: how often does the diagnosis change at follow-up?. Brain 2009; 132 (Pt 10): 2878-2888
    CrossrefPubMedGoogle Scholar
  • 24 Carson A, Stone J, Hibberd C. et al. Disability, distress and unemployment in neurology outpatients with symptoms ‘unexplained by organic disease’. J Neurol Neurosurg Psychiatry 2011; 82 (07) 810-813
    CrossrefPubMedGoogle Scholar
  • 25 Stephen CD, Fung V, Lungu CI, Espay AJ. Assessment of emergency department and inpatient use and costs in adult and pediatric functional neurological disorders. JAMA Neurol 2021; 78 (01) 88-101
    CrossrefPubMedGoogle Scholar
  • 26 Tinazzi M, Gandolfi M, Landi S, Leardini C. Economic costs of delayed diagnosis of functional motor disorders: preliminary results from a cohort of patients of a specialized clinic. Front Neurol 2021; 12 (December): 786126
    CrossrefPubMedGoogle Scholar
  • 27 Perez DL, Aybek S, Popkirov S. et al; (On behalf of the American Neuropsychiatric Association Committee for Research. A review and expert opinion on the neuropsychiatric assessment of motor functional neurological disorders. J Neuropsychiatry Clin Neurosci 2021; 33 (01) 14-26
    CrossrefPubMedGoogle Scholar
  • 28 American Psychiatric Association; Diagnostic and Statistical Manual of Mental Disorders. 5th ed.;. 2013
    Google Scholar
  • 29 American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders. 5th ed. TR.; 2022. Available at: https://doi.org/10.1176/appi.books.9780890425787
    CrossrefGoogle Scholar
  • 30 Ludwig L, Pasman JA, Nicholson T. et al. Stressful life events and maltreatment in conversion (functional neurological) disorder: systematic review and meta-analysis of case-control studies. Lancet Psychiatry 2018; 5 (04) 307-320
    CrossrefPubMedGoogle Scholar
  • 31 Roelofs K, Keijsers GPJ, Hoogduin KAL, Näring GWB, Moene FC. Childhood abuse in patients with conversion disorder. Am J Psychiatry 2002; 159 (11) 1908-1913
    CrossrefPubMedGoogle Scholar
  • 32 Kletenik I, Holden SK, Sillau SH. et al. Gender disparity and abuse in functional movement disorders: a multi-center case-control study. J Neurol 2022; 269 (06) 3258-3263
    CrossrefPubMedGoogle Scholar
  • 33 Kletenik I, Sillau SH, Isfahani SA, LaFaver K, Hallett M, Berman BD. Gender as a risk factor for functional movement disorders: the role of sexual abuse. Mov Disord Clin Pract (Hoboken) 2019; 7 (02) 177-181
    CrossrefPubMedGoogle Scholar
  • 34 Hallett M, Aybek S, Dworetzky BA, McWhirter L, Staab JP, Stone J. Functional neurological disorder: new subtypes and shared mechanisms. Lancet Neurol 2022; 21 (06) 537-550
    CrossrefPubMedGoogle Scholar
  • 35 Kranick S, Ekanayake V, Martinez V, Ameli R, Hallett M, Voon V. Psychopathology and psychogenic movement disorders. Mov Disord 2011; 26 (10) 1844-1850
    CrossrefPubMedGoogle Scholar
  • 36 Spagnolo PA, Norato G, Maurer CW. et al. Effects of TPH2 gene variation and childhood trauma on the clinical and circuit-level phenotype of functional movement disorders. J Neurol Neurosurg Psychiatry 2020; 91 (08) 814-821
    CrossrefPubMedGoogle Scholar
  • 37 Tinazzi M, Geroin C, Erro R. et al. Functional motor disorders associated with other neurological diseases: beyond the boundaries of “organic” neurology. Eur J Neurol 2021; 28 (05) 1752-1758
    CrossrefPubMedGoogle Scholar
  • 38 Voon V, Gallea C, Hattori N, Bruno M, Ekanayake V, Hallett M. The involuntary nature of conversion disorder. Neurology 2010; 74 (03) 223-228
    CrossrefPubMedGoogle Scholar
  • 39 Edwards MJ, Adams RA, Brown H, Pareés I, Friston KJ. A Bayesian account of ‘hysteria’. Brain 2012; 135 (Pt 11): 3495-3512
    CrossrefPubMedGoogle Scholar
  • 40 Huys AML, Haggard P, Bhatia KP, Edwards MJ. Misdirected attentional focus in functional tremor. Brain 2021; 144 (11) 3436-3450
    CrossrefPubMedGoogle Scholar
  • 41 Pareés I, Saifee TA, Kassavetis P. et al. Believing is perceiving: mismatch between self-report and actigraphy in psychogenic tremor. Brain 2012; 135 (Pt 1): 117-123
    CrossrefPubMedGoogle Scholar
  • 42 Lidstone SC, Araújo R, Stone J, Bloem BR. Ten myths about functional neurological disorder. Eur J Neurol 2020; 27 (11) e62-e64
    CrossrefPubMedGoogle Scholar
  • 43 Lidstone SC, Nassif W, Juncos J, Factor SA, Lang AE. Diagnosing functional neurological disorder: seeing the whole picture. CNS Spectr 2020; 9: 1-8
    PubMedGoogle Scholar
  • 44 Carson A, Hallett M, Stone J. Assessment of patients with functional neurologic disorders. Handb Clin Neurol 2016; 139: 169-188
    CrossrefPubMedGoogle Scholar
  • 45 Gilmour GS, Lidstone SC, Lang AE. The diagnosis of functional movement disorder. Pract Neurol 2022; (March/April): 40-53
    PubMedGoogle Scholar
  • 46 Gupta A, Lang AE. Psychogenic movement disorders. Curr Opin Neurol 2009; 22 (04) 430-436
    CrossrefPubMedGoogle Scholar
  • 47 Aybek S, Perez DL. Diagnosis and management of functional neurological disorder. BMJ 2022; 376: o64
    CrossrefPubMedGoogle Scholar
  • 48 Espay AJ, Aybek S, Carson A. et al. Current concepts in diagnosis and treatment of functional neurological disorders. JAMA Neurol 2018; 75 (09) 1132-1141
    CrossrefPubMedGoogle Scholar
  • 49 Baizabal-Carvallo JF, Jankovic J. Distinguishing features of psychogenic (functional) versus organic hemifacial spasm. J Neurol 2017; 264 (02) 359-363
    CrossrefPubMedGoogle Scholar
  • 50 Laub HN, Dwivedi AK, Revilla FJ, Duker AP, Pecina-Jacob C, Espay AJ. Diagnostic performance of the “Huffing and Puffing” sign in functional (psychogenic) movement disorders. Mov Disord Clin Pract (Hoboken) 2015; 2 (01) 29-32
    CrossrefPubMedGoogle Scholar
  • 51 Daum C, Gheorghita F, Spatola M. et al. Interobserver agreement and validity of bedside ‘positive signs’ for functional weakness, sensory and gait disorders in conversion disorder: a pilot study. J Neurol Neurosurg Psychiatry 2015; 86 (04) 425-430
    CrossrefPubMedGoogle Scholar
  • 52 Baizabal-Carvallo JF, Jankovic J. Functional (psychogenic) stereotypies. J Neurol 2017; 264 (07) 1482-1487
    CrossrefPubMedGoogle Scholar
  • 53 Aboud O, Al-Salaimeh A, Kumar Raina S, Sahaya K, Hinduja A. Positive clinical signs in neurological diseases - an observational study. J Clin Neurosci 2019; 59: 141-145
    CrossrefPubMedGoogle Scholar
  • 54 Hallett M. Neurophysiologic studies of functional neurologic disorders. Handb Clin Neurol 2016; 139: 61-71
    CrossrefPubMedGoogle Scholar
  • 55 Lang AE. Phenomenology of psychogenic movement disorders. In: Hallet M, Lang AE, Jankovic J. et al., eds. Psychogenic Movement Disorders and Other Coversion Disorders. Cambridge, UK: Cambridge University Press; 2011: 6-13
    Google Scholar
  • 56 van der Salm SMA, Erro R, Cordivari C. et al. Propriospinal myoclonus: clinical reappraisal and review of literature. Neurology 2014; 83 (20) 1862-1870
    CrossrefPubMedGoogle Scholar
  • 57 Ambar Akkaoui M, Geoffroy PA, Roze E, Degos B, Garcin B. Functional motor symptoms in parkinson's disease and functional parkinsonism: a systematic review. J Neuropsychiatry Clin Neurosci 2020; 32 (01) 4-13
    CrossrefPubMedGoogle Scholar
  • 58 Ganos C, Edwards MJ, Bhatia KP. The phenomenology of functional (psychogenic) dystonia. Mov Disord Clin Pract (Hoboken) 2014; 1 (01) 36-44
    CrossrefPubMedGoogle Scholar
  • 59 Schrag A, Trimble M, Quinn N, Bhatia K. The syndrome of fixed dystonia: an evaluation of 103 patients. Brain 2004; 127 (Pt 10): 2360-2372
    CrossrefPubMedGoogle Scholar
  • 60 Stamey W, Jankovic J. The other Babinski sign in hemifacial spasm. Neurology 2007; 69 (04) 402-404
    CrossrefPubMedGoogle Scholar
  • 61 Fasano A, Valadas A, Bhatia KP. et al. Psychogenic facial movement disorders: clinical features and associated conditions. Mov Disord 2012; 27 (12) 1544-1551
    CrossrefPubMedGoogle Scholar
  • 62 Mishra A, Pandey S. Cranial functional movement disorders: a case series with literature review. Tremor Other Hyperkinet Mov (N Y) 2020; 10 (01) 33
    CrossrefPubMedGoogle Scholar
  • 63 Ganos C, Aguirregomozcorta M, Batla A. et al. Psychogenic paroxysmal movement disorders–clinical features and diagnostic clues. Parkinsonism Relat Disord 2014; 20 (01) 41-46
    CrossrefPubMedGoogle Scholar
  • 64 Demartini B, Ricciardi L, Parees I, Ganos C, Bhatia KP, Edwards MJ. A positive diagnosis of functional (psychogenic) tics. Eur J Neurol 2015; 22 (03) 527-e36
    CrossrefPubMedGoogle Scholar
  • 65 Bhatia KP, Bhatt MH, Marsden CD. The causalgia-dystonia syndrome. Brain 1993; 116 (Pt 4): 843-851
    CrossrefPubMedGoogle Scholar
  • 66 Fasano A, Tinazzi M. Functional facial and tongue movement disorders. Handb Clin Neurol 2016; 139: 353-365
    CrossrefPubMedGoogle Scholar
  • 67 Roper LS, Saifee TA, Parees I, Rickards H, Edwards MJ. How to use the entrainment test in the diagnosis of functional tremor. Pract Neurol 2013; 13 (06) 396-398
    CrossrefPubMedGoogle Scholar
  • 68 Fahn S, Williams DT. Psychogenic dystonia. Adv Neurol 1988; 50: 431-455
    PubMedGoogle Scholar
  • 69 Walzl D, Solomon AJ, Stone J. Functional neurological disorder and multiple sclerosis: a systematic review of misdiagnosis and clinical overlap. J Neurol 2022; 269 (02) 654-663
    CrossrefPubMedGoogle Scholar
  • 70 Wangaryattawanich P, Rutman AM, Petcharunpaisan S, Mossa-Basha M. Incidental findings on brain magnetic resonance imaging (MRI) in adults: a review of imaging spectrum, clinical significance, and management. Br J Radiol 2022; (January): 1-13
    PubMedGoogle Scholar
  • 71 Katzman GL, Dagher AP, Patrona NJ. Incidental findings on brain magnetic resonance imaging from 1,000 asymptomatic volunteers. Evid Based Eye Care 2000; 1 (02) 114-115
    CrossrefPubMedGoogle Scholar
  • 72 Li Y, Thompson WK, Reuter C. et al; ABCD Consortium. Rates of incidental findings in brain magnetic resonance imaging in children. JAMA Neurol 2021; 78 (05) 578-587
    CrossrefPubMedGoogle Scholar
  • 73 Kerr WT, Lee JK, Karimi AH. et al. A minority of patients with functional seizures have abnormalities on neuroimaging. J Neurol Sci 2021; 427 (June): 117548
    CrossrefPubMedGoogle Scholar
  • 74 Schwingenschuh P, Saifee TA, Katschnig-Winter P. et al. Validation of “laboratory-supported” criteria for functional (psychogenic) tremor. Mov Disord 2016; 31 (04) 555-562
    CrossrefPubMedGoogle Scholar
  • 75 Saranza G, Vargas-Mendez D, Lang AE, Chen R. Suggestibility as a valuable criterion for laboratory-supported definite functional movement disorders. Clin Neurophysiol Pract 2021; 6: 103-108
    CrossrefPubMedGoogle Scholar
  • 76 Chen KS, Chen R. Principles of electrophysiological assessments for movement disorders. J Mov Disord 2020; 13 (01) 27-38
    CrossrefPubMedGoogle Scholar
  • 77 Gaig C, Martí MJ, Tolosa E. et al. 123I-Ioflupane SPECT in the diagnosis of suspected psychogenic Parkinsonism. Mov Disord 2006; 21 (11) 1994-1998
    CrossrefPubMedGoogle Scholar
  • 78 Walzl D, Carson AJ, Stone J. The misdiagnosis of functional disorders as other neurological conditions. J Neurol 2019; 266 (08) 2018-2026
    CrossrefPubMedGoogle Scholar
  • 79 Gelauff JM, Carson A, Ludwig L, Tijssen MAJ, Stone J. The prognosis of functional limb weakness: a 14-year case-control study. Brain 2019; 142 (07) 2137-2148
    CrossrefPubMedGoogle Scholar
  • 80 Stone J, Smyth R, Carson A. et al. Systematic review of misdiagnosis of conversion symptoms and “hysteria”. BMJ 2005; 331 (7523): 989-991
    CrossrefPubMedGoogle Scholar
  • 81 Coebergh JA, Wren DR, Mumford CJ. ‘Undiagnosing’ neurological disease: how to do it, and when not to. Pract Neurol 2014; 14 (06) 436-439
    CrossrefPubMedGoogle Scholar
  • 82 Shill H, Gerber P. Evaluation of clinical diagnostic criteria for psychogenic movement disorders. Mov Disord 2006; 21 (08) 1163-1168
    CrossrefPubMedGoogle Scholar
  • 83 Thomas M, Vuong KD, Jankovic J. Long-term prognosis of patients with psychogenic movement disorders. Parkinsonism Relat Disord 2006; 12 (06) 382-387
    CrossrefPubMedGoogle Scholar
  • 84 Jankovic J, Vuong KD, Thomas M. Psychogenic tremor: long-term outcome. CNS Spectr 2006; 11 (07) 501-508
    CrossrefPubMedGoogle Scholar
  • 85 Ettinger AB, Dhoon A, Weisbrot DM, Devinsky O. Predictive factors for outcome of nonepileptic seizures after diagnosis. J Neuropsychiatry Clin Neurosci 1999; 11 (04) 458-463
    CrossrefPubMedGoogle Scholar
  • 86 Stone J. Functional neurological disorders: the neurological assessment as treatment. Pract Neurol 2016; 16 (01) 7-17
    CrossrefPubMedGoogle Scholar
  • 87 Stone J, Carson A, Hallett M. Explanation as treatment for functional neurologic disorders. Handb Clin Neurol 2016; 139: 543-553
    CrossrefPubMedGoogle Scholar
  • 88 Stone J, Edwards M. Trick or treat? Showing patients with functional (psychogenic) motor symptoms their physical signs. Neurology 2012; 79 (03) 282-284
    CrossrefPubMedGoogle Scholar
  • 89 MacDuffie KE, Grubbs L, Best T. et al. Stigma and functional neurological disorder: a research agenda targeting the clinical encounter. CNS Spectr 2020; 26 (06) 1-6
    PubMedGoogle Scholar
  • 90 Gelauff JM, Rosmalen JGM, Carson A. et al. Internet-based self-help randomized trial for motor functional neurologic disorder (SHIFT). Neurology 2020; 95 (13) e1883-e1896
    CrossrefPubMedGoogle Scholar
  • 91 Lidstone SC, MacGillivray L, Lang AE. Integrated therapy for functional movement disorders: time for a change. Mov Disord Clin Pract (Hoboken) 2020; 7 (02) 169-174
    CrossrefPubMedGoogle Scholar
  • 92 Edwards MJ. Functional neurological disorder: lighting the way to a new paradigm for medicine. Brain 2021; 144 (11) 3279-3282
    CrossrefPubMedGoogle Scholar
  • 93 NHS Scotland. Stepped care for functional neurological symptoms. Healthc Improv Scotl 2012. Accessed February 6, 2023 at: https://www.healthcareimprovementscotland.org/idoc.ashx?docid=6d302668-ff12-4f53-b547-72c19531e37a&version=-1
    PubMedGoogle Scholar
  • 94 Stone J, Sharpe M, Rothwell PM, Warlow CP. The 12 year prognosis of unilateral functional weakness and sensory disturbance. J Neurol Neurosurg Psychiatry 2003; 74 (05) 591-596
    CrossrefPubMedGoogle Scholar
  • 95 Duncan R, Horwood J, Razvi S, Mulhern S. Psychogenic nonepileptic seizures that remit when the diagnosis is given: Just good luck?. Epilepsy Behav 2020; 102: 106667
    CrossrefPubMedGoogle Scholar
  • 96 MacGillivray L, Lidstone SC. The biopsychosocial formulation for functional movement disorder. In: LaFaver K, Maurer CW, Nicholson TR, Perez DL. eds. Functional Movement Disorder: An Interdisciplinary Case-Based Approach. Totowa, NJ: Humana Press; 2022
    CrossrefGoogle Scholar