Conversion Disorder has had a name recently with the update of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) – Functional Neurological Symptom Disorder (FNSD).

The prevalence of FNSD is estimated to have a 1-3% occurrence rate in general population. In neurological outpatient clinics, the incident is thought to be as high as 25-30%.

“medically unexplained, neurological symptoms that are believed to develop
unintentionally in reaction to psychological and environmental factors
such as trauma or daily stressors.”

In previous years FNSD aetiology was believed to be anxiety/stress related. Sigmund Freud a 19th Century Austrian neurologist and founder of psychoanalysis theorised that anxiety is “converted” into physical symptoms.

More recent work in this area now suggests it has many interrelated and complex variables with or without an anxiolytic or stressful preceding event which makes treatment less than simple or a “one size fits all” scenario.

Diagnosing FNSD

Diagnosis of FNSD is considered clinically when all diagnostic testing is not compatible with presenting signs and symptoms. Misdiagnosis does occur although is less likely today due to significant advancements in diagnostics and research.

The DSM-5 diagnostic criteria for FNSD (conversion disorder) are as follows:

• One or more symptoms of altered voluntary motor or sensory function.
• Clinical findings provide evidence of incompatibility between the symptom and recognised neurological or medical conditions.
• The symptom or deficit is not better explained by another medical or mental disorder.
• The symptom or deficit causes clinically significant distress or impairment in social, occupational, or other important areas of functioning or warrants medical evaluation.

PNSD is more prevalent in women than men, rarely found in children or the elderly and has an increased rate in people aged the mid to late 30s. Patient populations considered more at risk are those with a personality disorder or dissociative identity disorder.

Hoover’s sign is a test available to clinicians when assessing limb weakness which with a positive result “simply suggests that the majority of the weakness you are observing is not due to disease”.

  Breaking the news

”The doctor just told me my stroke is all in my head”.
”I can’t move my bloody arm”.
“I’m not making it up”.
“I’m not crazy”.

A diagnosis of FNSD can elicit strong emotional reactions from the patient and family if not handled sensitively. Mental health illness still has a stigma very much attached. Commonly families and staff don’t know what to say or how to care for the patient which can isolate the patient more with feelings of stigmatisation.

Use of a standardised non-judgmental script and having confidence in responding to emotive and challenging questions “you don’t believe me?” is necessary for the diagnosis disclosure.

The information provided is just as important as the delivery in explaining the diagnosis to your patient. While the initial conversation is not necessarily a nurses role, the ongoing reinforcement and provision of information related to the diagnosis certainly are.

Communicating that PNSD is a significant health condition requiring a whole of team effort for the condition to improve and symptoms resolve and as per below:
• the emphasis that symptoms are genuine and potentially reversible;
• explanation of the positive nature of the diagnosis (i.e., not a diagnosis of exclusion);
• simple advice about distraction techniques, self-help techniques and sources of information;
• referral on to appropriate physiotherapy and psychological services; and
• offering an outpatient review

Treatment options available

• The treatment plan found to be most effective is one with a motor learning program and a behavioural approach which is individualised within a multidisciplinary team environment.
• Person-centred goal setting with the patient/family is recommended.
• Behavior-oriented treatment strategies include unlearning maladaptive responses to eliminate example for the patients’ belief the limb is paralysed by informing them 1. that all tests indicate the muscles and nerves are functioning normally 2. the brain is communicating with the nerves and muscles, and 3. this apparently lost ability is recoverable.
• Pharmacological treatment includes prescribing of antidepressants and anxiolytics if indicated.

Clinical Take Home Message

• FNSD is a significant health condition requiring a multidisciplinary treatment plan based on a motor learning and behavioural approach.
• FNSD has many interrelated and complex variables with or without an anxiolytic or stressful preceding event.
• Motor learning program with a behavioural approach which is individualised within a multidisciplinary team environment is most effective.
• Sensitivity is required when disclosing diagnosis and with ongoing communication due to stigma and spoken or unspoken sense of not being believed.
• Treatment options available include individualised motor learning and behavioural approach programs, anti-depressants, anxiolytics, education, and suggestive therapy.

Reference:
Carson A, Lehn A, Ludwig L, Stone J, 2016 Explaining functional disorders
in the neurology clinic: a photo story Pract Neurol;16:56–61. 
http://dx.doi.org/10.1136/ practneurol-2015-001241

Boeckle M, Liegl F, Jank R, Pieh C 2016 Neural correlates of conversion 
disorder: overview and meta-analysis of neuroimaging studies on motor
conversion disorder BMC Psychiatry,16:195 DOI 10.1186/s12888-016-0890-x