The symptom of functional weakness: a controlled study of 107 patients

Abstract

Functional weakness describes weakness which is both internally inconsistent and incongruent with any recognizable neurological disease. It may be diagnosed as a manifestation of conversion disorder or dissociative motor disorder. Other names include psychogenic or 'non-organic' paralysis. We aimed to describe the incidence, demographic and clinical characteristics of cases with functional weakness of less than 2 years duration, and to compare these with controls with weakness attributable to neurological disease. Both cases and controls were recruited from consultant neurologists in South East Scotland. Participating patients underwent detailed assessments which included: physical examination, structured psychiatric interview (Structured Clinical Interview for the Diagnostic and Statistical Manual of Mental Disorders), measures of symptoms, disability and distress [Short Form (36) Health Survey, Hospital and Anxiety Depression Scale], and assessment of their illness beliefs using an augmented version of the Illness Perception Questionnaire. In total, 107 cases (79% female, mean age 39 years, median duration of illness 9 months) were recruited. This number suggests a minimum annual incidence of 3.9/100 000. Forty-six controls (83% female, median age 39 years, duration 11 months) were also recruited. Compared to controls, cases had similar levels of disability but more physical symptoms, especially pain. They had a higher frequency of psychiatric disorders, especially current major depression (32 versus 7%, P < 0.0001), generalized anxiety disorder (21 versus 2%, P < 0.005), panic disorder (36 versus 13%, P < 0.001) and somatization disorder (27 versus 0%, P < 0001). There was no difference in median self-rated anxiety and depression scores. Paradoxically, they were less likely than controls to agree that stress was a possible cause of their illness (24 versus 56%, P < 0.001). Cases were twice as likely as controls to report that they were not working because of their symptoms (65 versus 33%, P < 0.0005). Functional weakness is a commonly encountered clinical problem. Patients with this symptom are as disabled as patients with weakness of similar duration due to neurological disease. There is a paradox between the frequency of depression and anxiety diagnoses and the patient's willingness to accept these as potentially relevant to their symptoms. We discuss the theoretical and practical implications of these findings for the concept of conversion disorder.

Distinctive neuropsychological profiles differentiate patients with functional memory disorder from patients with amnestic-mild cognitive impairment

“…A possible route for treatment would be to investigate psychosocial risk factors (39) and explore beliefs about memory failures. We noted in clinical communications between the neuropsychologist and the patient, that only one person admitted that mood (in this case, anxiety) could be the cause of their subjective memory concerns, which supports research in functional weakness patients (13). Memory complaints in FMD are similar to those experienced by many healthy ageing people (e.g., forgetting PIN numbers, getting lost mid-conversation, forgetting the reason for walking into a room).…”

Brain circuits implicated in psychogenic paralysis in conversion disorders and hypnosis

“…Thus, while we nowadays have a much better knowledge of brain circuits implicated in complex neurological movement deficits, such as Parkinson or Huntington disease, or those affected in complex mental disturbances such as obsessive-compulsive disorders or depression, our conceptual approach to psychogenic deficits is still very much based on ideas initially formulated by Charcot or Freud, and our mechanistic understanding of their putative neural substrates in the brain is still rudimentary. This state of affairs is even more striking when considering that conversion disorders are among the most common diagnosis in neurology, thought to represent at least 4% of all admissions on a general clinical wards and thus equal in frequency to multiple sclerosis or epilepsy [93,96].…”

A General Pediatrics and Integrative Medicine Approach to Pervasive Refusal Syndrome: A Case Report

“…Although she had illness gains in the form of paternal attention, her condition fit less with conversion disorder, which more typically affects one organ system at a time; additionally, neurologic inconsistencies that are diagnostic of conversion muscle weakness were missing. 9 A psychotic disorder with predominantly negative symptoms was ruled out because she was always adequate in visual contact and her sense of reality was intact. Although mutism can be part of catatonia, she had none of the motor signs of this condition.…”