LEMON SEED for Functional Neurological Disorders

Mar 04, 2022


No! I am not suggesting you eat lemon seeds if you have a Functional Neurological Disorder (FND). L.E.M.O.N. S.E.E.D is the ordinary acronym that arose from one of our recent professional development sessions at Advanced Neuro Rehab.  I know it’s not great, but it stuck! Anyway, ordinary acronyms seem to be all the rage in research these days, so why not join in?

There seems to be a promising paradigm shift in the world of Functional Neurological Disorders. A glimmer of hope that a more supportive and structured rehabilitation model can help people with what is likely to be the most common neurological disorder out there in the community. Yes, I referred to FND as a ‘neurological’ disorder, because that is where I feel progress can commence.

The history of FND is deeply routed in the field of psychiatry, which helped move away from previous theories that linked FND with the uterus (‘hysteria’) (1) and with demonic possession! FND also helped propel Sigmund Freud into stardom, with the idea of the brain converting psychic stressors into physical signs. More recently FNDs have found themselves at the intersection of psychiatry and neurology, where it has remained classified as a ‘conversion’ disorder (2). The good news is, this will change in March 2022.

More recently the term ‘Functional Neurological Symptom Disorder  ’ has taken over from ‘conversion’ and sometimes ‘non-organic’ symptoms, with a clearer diagnostic approach, and directions for a more multidisciplinary rehabilitation direction for care and treatment (3). It is no longer a diagnosis of exclusion but rather a condition with its own criteria of unique signs and symptoms, ranging from seizures, to weakness, to blindness, to difficulty walking. The more we learn about the brain and its various networks and functions, the more we recognise the limitations of previous classifications that separated out the physical, cognitive, and behavioural functions of the brain. From a neurological physiotherapist point of view, it becomes clear that movement or motor control is not immune to the influences of unconscious cognitive and emotional stressors. We must also realise the limitations in our understanding of brain networks, but we hope that in the future, neuroscience will help us understand why people develop FND in the first place. This includes up to 50% of people with FND who have no identifiable stressor or trauma that may have triggered these neurobiological changes.

While progress continues to be made in our understanding of the psychological and pathophysiological factors relevant to FND, it is important that rehabilitation health professionals consider how we can now best educate, support, and coach people with FND utilising current knowledge. For health professionals who work with functional movement disorders, I recommend reviewing the 10 Movement Training Principles and joining one of our discussions about these principles in the context of FND.

Anyway, back to LEMON SEED. Here are some important things you might consider when working with people with FND.


I know, I know what many of you are thinking. Here is another ‘captain obvious’ academic telling us to listen to our patients – so I apologise in advance. Its’ just that actively listening to people with FND has taught me a great deal over the years. The themes are not unfamiliar to us who work in neuro rehab – anxiety, fear, frustration with a lack of clear diagnosis, scepticism about therapy, prognosis, and general disappointment with the medical profession. Then underneath these understandable emotions can be determination, fight, and a preparedness to accept help and try something. Finally, you can uncover the person, their identity and the world they live in. While I know goal setting is important, this early moment of listening is not necessarily a time to pinpoint any specific rehab goals, because I find this is not the time to limit the discussion in order to fit into a little rehab toolbox. Listening should remain an open house, and the beginning of the most important step – trust.


Again, let’s not be patronising here. We know education is probably the most important part of the diagnostic period of FND (4). And in 2022, there is more good information available to people on the internet than ever before. That is why I like to ask questions like,

‘How much do you know about FND?’

‘Does the information you have received about FND make sense to you?’

‘Do you have any questions you would like to ask me about FND?’

Here we can be honest in explaining that FND is common. If you are like our clinic, we explain that we see many people with FND. The popular ‘hardware’ and ‘software’ analogies for FND are pretty good, but still leave some confused. This explains that the ‘hardware’ of the brain is intact, but the ‘software’ is not functioning properly. This explanation can be less effective for those that are not very computer savvy, and we may soon run into trouble when future research is likely to find structural ‘hardware’ problems!

Personally, with functional movement disorders, I talk about motor control, and what we know about how the brain plans, prepares, and executes movement. Any of these steps can be interrupted, and many of our objective neurological tests struggle to capture abnormal brain networks, particularly those networks involved in movement planning. I explain that in neurology we see may instances where the brain knows exactly what to do yet can’t access the correct plans. This may result in dyspraxia movements after stroke, freezing of gait in Parkinson’s and involuntary muscle spasms in dystonia. For each of these conditions there are different causes for the disruption to movement planning networks. In people with FND, it seems that these brain networks may be more vulnerable to corruption (5). Physical or emotional stressors may contribute to the network corruption in some, while for others the network might short-circuit for other unknown reasons – remembering the field of neurology is full of ‘unknown reasons’.

It is not unreasonable to provide hope at this stage. The reality is that many people with FND do well with rehabilitation. The brain does need the environment and opportunity to re-learn, and this is well worth a try!

Monitor other conditions

Don’t put all your eggs into one FND basket. Many signs and symptoms may be due to other conditions. Conditions that may well influence FND symptoms, but they may also be conditions that need to be treated in their own right. Ligament sprains, rheumatoid arthritis, anxiety, spasticity, neuralgia, migraine, or diabetes. You cannot engage in optimal rehabilitation unless all your medical conditions are carefully considered. Many people develop FND as an ‘overlay’ on top of these other conditions. For example, epileptic and non-epileptic seizures, functional gait disorders and chronic pain, concussion injury and functional somatic symptoms, and vestibular neuronitis and persistent postural-perceptual dizziness. It is surprisingly common to encounter a functional movement disorder that overlays with common neurological conditions.

It can be confusing to other professionals when they learn that our NeuroPhysiotherapists have spent time assessing and managing a focal issues like hip pain, positional vertigo or neck range of movement in a person with a functional movement disorder. Why would we focus on these specific areas, when excessive hypervigilant internal focus may already be maladaptive neural process in people with FND? (See later section on External Focus). The reason is because a well-designed rehabilitation plan may have recognised that the best way to manage a multifactorial problem, is to address multiple factors that are limiting the rehabilitation progress.

Ownership of program

If possible, hand over the keys of responsibility as early as day 1. The person with FND owns the rehab program, makes decisions, makes choices and will seek advice from you in a more coaching role.  Your advice will help provide a framework of prioritising the content, frequency and intensity of a home exercise program. When reviewing progress, I find it is a balance between providing support and understanding, giving praise for positive behaviour especially around adherence, and expressing satisfaction and pride in any new progress.

Never dismiss or deceive

This comes back to trust. Most of the setbacks we see with FND rehab stem from stigma, misinformation, and derogatory gossip. Many people, including health professionals, struggle to grasp the ideas behind FND, and remain convinced they are dealing with a malingerer, or a person who is deliberately being difficult, or even focussing too much on psychological factors.

We find most people with FND have had some adverse experiences. Open communication and keeping clear and regular communication with all other relevant health professionals is even more critical for FND rehab. It’s also useful to expect and prepare for more stigma, but it is not useful for these bad experiences to become a major focus. Acknowledge it, prepare for it, and move on.

Slow progress

Making positive progress is the aim, and fast progress can be exciting. However, the more I read and learn about neuroplastic processes that underlie much of our therapy – slow, incremental progress makes sense. Small and slow steps provide more time for adaptation to new sensorimotor experiences, and the accompanying emotions that often arise. Slow progress reduces the intense internal or external pressure around expectation, hope and desires. Progress will change rehab goals, but are people ready for what that entails for their life? These individual physical and psychological experiences can make goal directed rehab complex but planning to go slowly can at least make it less complicated.

External Focus

It seems that for people with functional movement disorders, there are interruptions in the predictive sensorimotor control pathways that alter the sense of agency and control with specific movements. This may well be what contributes to common dissociative symptoms and a deviation to a maladaptive motor control strategy that can use too much internal attentional focus. If people move while attention is focussed more externally, we often see noticable improvements, and more normal movement performance (6). Historically the term ‘distraction’ is used, but this has its problems. Distraction can infer some kind of conscious deception, and when see it in diagnostic tests, it can sometimes seem like we are trying to ‘catch them out’. Trust is still paramount, so we prefer to use the term external focus, like we do with other movement planning disorders. Practicing movement with different degrees of external attentional focus in training can range from visual targets, feedback of results and dual tasks. When movement is improved as a result, it is an important discovery that should be welcomed with enthusiasm and optimism – even if it is only fleeting. Video feedback can be very useful in this circumstance. Attentional focus, like the other training principles (7), can become a target for slow progress.

Expect setbacks

It’s pretty unusual not to have setbacks. Infact, I cannot recall anyone who has had a linear path toward recovery, even in those with the best outcomes. Setbacks are a normal part of the journey, and each setback and subsequent improvement, may be the ideal long-term pathway for rehabilitation. Some setbacks can be explained by external or internal stressors and should be acknowledged. But some setbacks occur with no rhyme or reason, and in this situation can be acknowledged as one of the brains many mysteries. I find that as I get to know many people with FND a little more, it becomes clearer that they are pretty hard on themselves, so it’s best not to get too hung up on setbacks.

Design in aspirational goals

Goals should remain part of a continuing conversation. I am not a fan of SMART goals which somehow spread across into the rehabilitation field from the business sector, and this may be a situation where attempting SMART goals could be detrimental (8). A person with FND can set some goals, revisit, change, add new goals and keep thinking about them. Don’t be afraid to be aspirational. If progress is slow, it is good to plan a discuss how a road to recovery might look. From my experience that road is at least 6 months long. Experience is invaluable here, so support and advice from experienced colleague can really help. For the person with FND, walking out of a therapy session with a 6-month plan is powerful step that prompts some healthy contemplation.

It will be interesting to look back on LEMON SEED in 5-10 years to see how our approach changes with evidence and more experience. In the meantime, it is a nice place to start, while we support people with FND today. Our staff are considering putting together an FND toolbox course, so that may be our next goal!

Associate Professor James McLoughlin


  1. Trimble M, Reynolds EH. A brief history of hysteria: from the ancient to the modern. In: Handbook of clinical neurology. Elsevier; 2016. p. 3–10.
  2. American Psychiatric Association DS, Association AP, Others. Diagnostic and statistical manual of mental disorders: DSM-5. Vol. 5. American psychiatric association Washington, DC; 2013.
  3. Aybek S, Perez DL. Diagnosis and management of functional neurological disorder. BMJ. 2022 Jan 24;376:o64.
  4. Stone J, Burton C, Carson A. Recognising and explaining functional neurological disorder. BMJ. 2020 Oct 21;371:m3745.
  5. Drane DL, Fani N, Hallett M, Khalsa SS, Perez DL, Roberts NA. A framework for understanding the pathophysiology of functional neurological disorder. CNS Spectr. 2020 Sep 4;1–7.
  6. Nielsen G, Stone J, Matthews A, Brown M, Sparkes C, Farmer R, et al. Physiotherapy for functional motor disorders: a consensus recommendation. J Neurol Neurosurg Psychiatry. 2015 Oct;86(10):1113–9.
  7. McLoughlin J. OpenPhysio| Journal. [Internet]. Available from:
  8. Swann C, Jackman PC, Lawrence A, Hawkins RM, Goddard SG, Williamson O, et al. The (over)use of SMART goals for physical activity promotion: A narrative review and critique. Health Psychol Rev. 2022 Jan 31;1–16.

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