Functional Neurological Disorders

Question 1

Hoover’s sign

• what does it test
• how can you explain this to a patient

Answer 1

FND affecting hip extension

• inability to extend hip in isolation
• can flex hip inconsciously when other leg is flexed against resistance

Issue with voluntary muscle movement

Question 2

Epidemiology of FND and persistent physical symptoms

Answer 2

Occur in all specialities
-IBS, fibromyalgia, chronic pelvic pain, atypical chest pain, dysfunctional breathing

FND - 1/3d of neurology OP
-can present with any neurological symptom (seizure, paralysis, movement disorder, cognition)

Question 3

What is vital to emphasise to the patient

Answer 3

FNDs are not
-imagined
-put on
-not real
We do believe them, their experiences are real
Assume that they are being honest, unless you have evidence to suggest factitious disorder or malingering (but this is very rare

A problem with how people access or control their body normally
Not due to disease that damages the brain or nerves

Question 4

Things to ask about in a history

Examination findings

Answer 4

It is not a diagnosis of exclusion

Let the patient list all their symptoms
ICE
Ask about their experiences with other doctors
Ask whether their symptoms have impacted their mood?

Multiple episodes of the PC
Past persistent symptoms
Life events, trauma
Dissociation, derealisation?
Psych history

BUT YOU DO NOT NEED TO HAVE EXPERIENCED TRAUMA OR STRESS TO HAVE FND

Decreased conscious vs uncoonscious function

• observed strength, balance, vision is more evident than on examination - due to the attention given to the action
• Hoovers

Question 5

Presentation of dissociative seizures vs epileptic seizures

Answer 5

Key differences
-more likely to be motor (thrashing instead of lying still)
-long duration - 5mins+
-gradual onset
fluctuating course
-eyes closed that resist opening
-partially retained awareness
-tongue biting rare
-side to side head movement

Question 6

How to communicate the diagnosis to the patient

Answer 6

Start by offering a clear diagnosis of what they DO HAVE
Explain that there are no problems in your muscle or nerve functions because of your ability to move them unconsciously.
But there is a problem with how your brain controls voluntary movement

There is a brain mechanism called dissociation which can be experienced by all people but in individuals with dissociative seizures, it happens at inappropriate times

We don’t always know the cause, life trama and stresses may contribute but its not the case for many people

There are treatments and support we can provide to help you recover fully but they may not be effective in everyone

Question 7

Causes of FNS

Answer 7

Mechnisms

• role of attention and expectation
• dissociation

Causes
Predisposing factors
-trauma
-personality
-experience of illness
Precipitating factors
-life events
-physical illness
Maintaining factors
-secondary gain
-pain
-medication

Question 8

How do life events relate to functional symptoms

Answer 8

Half of individuals with FND has stressful life events in the month before symptoms

Half of individuals had an event to escape from the stressor before their FND

Sexual abuse is more common

But the majority of life events and stressors are not brought up in clinical interviews

Question 9

Management of functional disorders

Answer 9

Start with supportive management in primary + secondary care

• avoid extra tests
• reduce analgesia
• discuss coping strategies
• manage comorbid anxiety and depression
• provide sources of info online and leaflets, peer support groups

OP CBT, physio, SALT

Intensive OP or IP treatment with MDT