Functional Neurological Symptom Disorder

Question 1

Define A functional Neurological Disorder

Answer 1

Patients experience neuro symptoms such as weakness, movement disorders, sensory symptoms and blackouts
Their brain is structurally normal, but functions incorrectly
“functional symptoms, also called ‘medically unexplained,’ ‘psychogenic,’ or ‘hysterical,’ are symptoms that are clinically recognizable as not being caused by a definable organic disease

Question 2

How would you approach the history of someone potentially with an FND?

Answer 2

• You want to know the symptoms and any disability.
• Their beliefs about their illness
• If they have any work, money, law or relationship issues (caused by or potentially causing the symptoms)
• History of Abuse
• Investigate their old notes (will typically have a big binder of unexplained symptoms)

Question 3

How would an FND show up on a neuro exam?

Answer 3

• inconsitencies
• Notable absence of specific disease signs
• Tremors that disappear on distraction
• Fixed Dystonia
• Give way Weakness
• Inverted Pyramidal Weakness
• Leg dragging paralysis with a rotated hip

Question 4

What is give way weakness?

Answer 4

Patients limb puts up resistance then suddenly gives way completely, not found in organic neuro disorders

Question 5

What is inverted pyramidal weakness?

Answer 5

UMN lesions cause pyramidal weakness which is weakness in upper limb extensors and lower limb flexors so the patient takes on the appearance of a pyramid (flexed arms and extended legs)

Question 6

What is a fixed dystonia?

Answer 6

A fixed abnormal limb posture after a minor peripheral injury
This is a sign of an FND as it has no organic cause

Question 7

What are +ve functional signs?

Answer 7

Signs of neuro symptoms that are clearly functional:

• Hoovers sign
• Functional sensory disturbance (sensory loss straight down entire midline)

Question 8

What is hoovers sign?

Answer 8

Example of a +ve functional sign

One hip’s extension is weak but when you ask them to flex the other hip the first one extends strongly (a physiological reflex that should also be reduced if there’s an organic cause for the weakness)

Question 9

What tests can be done for FNDs?

Answer 9

• MRI
• Video EEG (Can show patients thier brain is normal during their “epileptic” attacks)
• Functional MRI

Question 10

How should we give the diagnosis of an FND?

Answer 10

Important to give a +ve diagnosis rather than telling them they're fine
Impress that:
- Its common
- It will improve
- You believe them
- And self-help is vital

You can explain it through the software/hardware metaphor

Be sure to educate their friends/family/carers

Question 11

How can depression relate to FNDs?

Answer 11

Depression or anxiety to any number of causes can result from or cause FNDs.
Treating with antidepressants may help their symptoms

Question 12

How do we manage an FND?

Answer 12

• Most remain in primary care
• In many cases diagnosis and advice from a neurologist is enough
• Can refer to physiotherapists, psychiatry, psychology (CBT), physical rehab and/or counselling

Question 13

What should you be aware of post-diagnosis in FND patients?

Answer 13

• Misdiagnosis is actually the same as for all neuro disorders (5%)
• Litigation is possible
• Need of or fraud for benefits, aids and appliances