CHPR: Please begin by giving us an overview of functional neurological disorder.

Dr. Gilmour: Functional neurological disorder, or FND, is a condition in which patients experience neurologic symptoms that result from, essentially, malfunctioning brain networks. The problem seems to lie with how signals are relayed from the brain to control movement and with how signals are integrated to interpret information coming from the body. I find the hardware/software analogy quite useful: If we think of the brain as a computer, FND represents a malfunctioning of the software. Patients with FND experience a wide variety of neurologic symptoms, ranging from weakness and movement problems to seizure-like episodes and cognitive symptoms. 

CHPR: And these symptoms are often quite disabling, right? 

Dr. Gilmour: Absolutely. And it’s important to emphasize that this diagnosis is separate from factitious disorder and malingering. In FND, the symptoms are real, they are involuntary, and they are disabling.

CHPR: For readers who are familiar with the term “conversion disorder,” it’s worth pointing out that when the DSM-5-TR came out in 2022, the terminology was changed to “functional neurological symptom disorder.”

Dr. Gilmour: Many people still use older terminology, like “conversion disorder,” “psychogenic nonepileptic seizures,” or “nonepileptic attacks,” so the nomenclature is a work in progress. I would recommend using the term “functional,” which can be combined into “functional neurological disorder,” “functional seizures,” and “functional movement disorder,” for example.

CHPR: What are the most common presentations of FND?

Dr. Gilmour: FND can present with essentially any neurological symptom, but the most common are functional seizures and functional movement disorder. In functional seizures, patients experience episodes that resemble epileptic seizures or syncope with altered responsiveness. With functional movement disorder, patients present with abnormal movements, like tremor, dystonia, jerky or myoclonic-like movements, gait disorders, or weakness. Around half of patients have multiple motor phenomenologies (Gilmour GS et al, CNS Spectr 2023;28(6):747–755). Another common manifestation is persistent postural-perceptual dizziness, or PPPD, where patients experience chronic dizziness and unsteadiness. There are also functional cognitive disorder, functional somatosensory or visual symptoms, and functional speech or swallowing disorders. 

CHPR: It’s interesting to hear that patients often present with multiple and varied symptoms.

Dr. Gilmour: Right. Many patients with FND have more than one of these subtypes, and the subtypes often shift over time. In my functional movement disorder clinic, I focus my assessment on the most bothersome symptoms at the present time, knowing they might shift the next time I see the patient. And our patients often report other symptoms like pain, fatigue, cognitive fog, and sleep disturbances, which can be even more disabling than their primary neurological symptoms. So, we think of FND as a multisystem syndrome. 

CHPR: Some years ago, I encountered a patient with functional blindness. Have you encountered such patients?

Dr. Gilmour: Absolutely, yes. I say “never say never” in FND—there is such a wide spectrum of possible presentations. With functional blindness, patients will display an optokinetic nystagmus response, indicating that light perception is happening, despite the patient’s experience of blindness. There isn’t much literature on this condition or on treatment strategies, but occipital transcranial magnetic stimulation has been successful in some cases (Ramsay N et al, Eye (Lond) 2024;38:2257–2266). 

CHPR: What risk factors have been identified for FND?

Dr. Gilmour: Given that FND is a complex neuropsychiatric condition, there isn’t a single unifying etiology. It’s best conceptualized using a biopsychosocial framework. One important risk factor is stressful life events and maltreatment, and in particular emotional neglect. Patients with FND are 3.5 times more likely to have experienced adverse life events compared to control subjects (Ludwig L et al, Lancet Psychiatry 2018;5(4):307–320). Female gender is sometimes considered to be a risk factor, but this may also partially be attributable to higher rates of childhood adverse events in women (Kletenik I et al, Mov Disord Clin Pract 2019;7(2):177–181). And psychiatric comorbidities like posttraumatic stress disorder, depression, and anxiety appear to be risk factors. Also, patients with certain neurological disorders like migraine, multiple sclerosis, and Parkinsonism have higher rates of FND (Walzl D et al, J Neurol 2022;269(2):654–663). 

CHPR: Please describe the workup of FND.

Dr. Gilmour: I’ll start by saying that FND is no longer considered a diagnosis of exclusion or medically unexplained. We assess for positive signs, both on history and physical examination, that allow us to rule in this diagnosis. Patients often describe a sudden or explosive onset of symptoms followed by a rapid accumulation of individual symptoms that lead to disability. It’s different from other neurological illnesses, which often have an insidious onset with a progressive worsening. Inconsistency in symptoms is common; patients describe good and bad days, waxing and waning of symptoms, and even spontaneous remissions. On exam, we look for evidence of symptomatic inconsistency, like variability of neurological signs, distractibility, and worsening of signs with attention. Variability manifests as changing patterns of neurological deficits throughout the assessment, such as a functional tremor changing frequency, direction, or body location. We observe the effects of distractibility when a patient’s abnormal signs cease as they stop paying attention to the affected body region. Conversely, signs will worsen in the context of attention, for example when we formally examine an affected limb. By following these steps, we can rule in the diagnosis, in many cases without requiring further investigation. 

CHPR: And for functional seizures, you’d also want to get an EEG, right?

Dr. Gilmour: Right. There are some FND presentations where we typically need to do more investigations, including functional seizures. There, a video EEG is the gold standard, ideally capturing one of the events in question.

CHPR: Once you’ve made your diagnosis, what do you do next?

Dr. Gilmour: The most important next step, which is often overlooked, is to give patients a clear diagnostic explanation. It’s hard for people with FND to get better if they don’t understand why they have their symptoms. I start by saying, “You have functional neurological disorder,” then I explain how the symptoms arise, showing patients the positive signs on their examination. I also emphasize that the condition is common and disabling, and I provide patients with the website www.neurosymptoms.org so that they can continue to educate themselves about FND after our consultation. A fantastic resource to help patients understand their diagnosis is Jon Stone’s article in Practical Neurology, “Functional Neurological Disorders: The Neurological Assessment as Treatment” (Stone J, Pract Neurol 2016;16(1):7–17). 

CHPR: It must be very reassuring for patients to hear that their symptoms are real. 

Dr. Gilmour: Absolutely. When I tell a patient with FND, “I don’t think you’re crazy,” I see their shoulders relax. It’s very important for them to hear that their symptoms and experiences are real and valid. 

CHPR: And what does treatment entail?

Dr. Gilmour: Rehabilitation for FND varies based on the most disabling symptoms. So, for functional movement disorder, we can help patients improve their motor symptoms with FND-specific physiotherapy techniques that aim to minimize self-focused attention, instead using distraction (such as with a cognitive task, like counting backwards by sevens) or tapping into automatically generated movements (like tossing a ball between the hands). It’s important for rehabilitation to focus on function, using specific activities as goals. It’s helpful to have patients use visualization to imagine normal movement prior to performing the movement, and I also like to use mirrors and video as they provide both distraction and feedback about patients’ movements. For functional seizures, various forms of psychotherapy are helpful, with cognitive behavioral therapy having the most evidence (Goldstein LH et al, Lancet Psychiatry 2020;7(6):491–505). Mindfulness-based psychotherapy, psychodynamic psychotherapy, and prolonged exposure therapy also appear effective at reducing symptoms. 

CHPR: Do you have any other tips for us to keep in mind when we treat these patients?

Dr. Gilmour: Before initiating a rehabilitation program, I ensure that patients understand and agree with their FND diagnosis. This is necessary for the therapeutic techniques we offer, which can be quite intensive and challenging. Are they ready and motivated to improve their symptoms? Are there barriers that first need to be addressed, like severe pain or fatigue? Have we identified their most bothersome symptoms so that we can select the most appropriate rehabilitation modality? So, we take an opt-in approach to rehabilitation.

CHPR: And what is the prognosis for patients with FND?

Dr. Gilmour: Without treatment, the prognosis is quite poor. A large systematic review of patients with functional movement disorder found that after about a mean duration of seven years, 40% of patients were unchanged or worse, and only about 20% had gone into remission (Gelauff J et al, J Neurol Neurosurg Psychiatry 2014;85(2):220–226). For functional seizures, the remission rate is a little bit higher, around 40%–50%. The mortality rate of patients with functional seizures is higher than the general population, so this isn’t a benign condition (Nightscales R et al, Neurology 2020;95(6):e643–e652). But with treatment, about two-thirds of FND patients get better and experience improvement in their quality of life. It’s important to think of FND as a chronic condition that will involve relapses over time, and the goal with rehabilitation is to support a patient’s self-management strategies so that they can recognize and manage their exacerbations when they occur. 

CHPR: What medications, if any, are used to treat FND?

Dr. Gilmour: Generally speaking, there is minimal evidence for the use of medications in the treatment of FND symptoms. If there is a psychiatric comorbidity, like depression, anxiety, or posttraumatic stress disorder, I often use psychiatric medications like antidepressants as appropriate for these symptoms. And for PPPD, there is some evidence for the use of selective serotonin reuptake inhibitors or serotonin/norepinephrine reuptake inhibitors in reducing dizziness (Staab JP, Semin Neurol 2020;40(1):130–137).

CHPR: Do you find yourself discontinuing medications that patients might not actually need, like antiepileptic drugs for patients with functional seizures? 

Dr. Gilmour: Yes. Patients with FND face so much iatrogenic harm, so not only is it important to take away medications that are not indicated, but it’s also important to communicate the diagnosis and treatment modalities to other providers involved in the patient’s care so we can prevent ongoing risks of harm. But about 20% of patients with functional seizures also have comorbid epileptic seizures, so we must be very careful about not discontinuing antiepileptic medications until we are certain there haven’t been any epileptic events in the past (Kutlubaev MA et al, Epilepsy Behav 2018;89:70–78). 

CHPR: In my experience, colleagues in neurology have often been reluctant to taper and discontinue antiepileptic drugs in patients with functional seizures even when the evidence of prior epileptic events is very slim. However, once we get a multidisciplinary dialogue going and have sufficient evidence for everyone to feel confident that it’s the right thing to do, then we have been able to successfully discontinue these medications, though this process can take some time.

Dr. Gilmour: Right. It’s not a risk-free decision, so it must be done with caution. Collaboration among team members is vital to achieve the best possible outcomes for our patients. 

CHPR: What advice do you have for psychiatrists who treat patients with FND?

Dr. Gilmour: Start by helping patients understand their illness, and consider using bedside ­techniques that can be helpful even in a short visit, like sensory grounding techniques, mindfulness, and relaxation and breathing techniques. We often see autonomic hyperarousal in patients, and these techniques are helpful not only for addressing those symptoms, but also for reducing FND symptoms. Other helpful interventions include screening for and managing comorbid psychiatric conditions, assessing for contributing psychosocial factors, and providing or facilitating psychotherapy.

CHPR: Please elaborate on those sensory grounding techniques.

Dr. Gilmour: Sensory grounding techniques can help for episodic symptoms or in moments of symptom escalation. The technique I often use is “5, 4, 3, 2, 1”: having the patient identify five things in the environment that they can see, four they can hear, three they can feel, two they can smell, and one they can taste, for example. Many of my patients carry something in their pocket, like a smooth stone, to help them ground in moments when symptoms escalate. They might also carry sour candies. I’m from Canada, where it gets really cold in the winter, so my patients will use their cold hands to touch their face as a seizure is coming on, and this helps prevent the seizure from occurring. 

CHPR: Thank you for talking with us about FND. It’s one of the most fascinating conditions we encounter.

Dr. Gilmour: Maybe I’m biased, but I totally agree.

CHPR: Thank you for your time, Dr. Gilmour.