Anaesthesia and the development of functional neurological disorder: A systematic review and case series

Improvement of functional paralysis following unexpected comatose states

Instances of recovery from a functional neurological disorder (FND) can shine a light on the nature of the condition and its potential treatment. Unexpected recovery of FND symptoms can occur after a comatose state or an anaesthetic, or after various other scenarios. Two illustrative cases exemplify the phenomenon. A 59-year-old man had an 8-year history of functional paraparesis that had developed subacutely following a car crash. The paralysis recovered dramatically after an episode of medically induced coma, administered because of SARS-CoV-2 acute respiratory distress. A 40-year-old woman had complete recovery of FND-related arm paralysis and associated chronic pain after a deliberate overdose that led to a comatose state necessitating a brief period of ventilation. We compare these with similar recoveries in other scenarios, such as following hypnosis or extreme external stress. We discuss the potential mechanisms for recovery and the implications for FND treatment.

Joint hypermobility in functional neurological disorder: A cross-sectional study

BACKGROUND

Functional Neurological Disorder (FND) is associated with anxiety and depression, and perhaps with joint hypermobility, which is itself associated with anxiety and depression. We conducted a survey to explore the relationship between these.

METHODS

An online survey of people with FND was conducted, with participants asked to nominate healthy controls from their social group to join. Participants were asked about their anxiety (measured with GAD7), depression (measured with PHQ9) and joint hypermobility (measured with 5PQ). A regression analysis was conducted using a general linear model.

RESULTS

215 people with FND and 22 people without FND were included in the analysis. GAD7, PHQ9 and hypermobility scores were all higher in the group with FND, with 74% of people with FND meeting the common cut-off for a diagnosis of joint hypermobility syndrome, as compared with 45% of those without FND. Anxiety, depression and joint hypermobility scores all predicted FND status, with joint hypermobility the strongest. Hypermobility moderated the effect of anxiety, with the effect being stronger at lower levels of anxiety.

CONCLUSION

While anxiety, depression and hypermobility symptoms each appear to contribute to FND, the role of anxiety is moderated by hypermobility, particularly when anxiety is lower.

Could motor blocks be a therapeutic option for treatment-resistant functional dystonia? A case series of three patients

The diagnosis of functional dystonia is challenging because it is difficult to distinguish functional dystonia from other types of dystonia. After diagnostic explanation, multidisciplinary care is recommended, but some patients are resistant to treatments. We used motor blocks in three patients with severe resistant functional dystonia of the upper limbs to test (i) whether joint contracture was present and (ii) whether motor blocks have a therapeutic effect on functional dystonia. Patient 1 showed a good and sustained therapeutic response, Patient 2 experienced a resolution of the dystonic posture that lasted for 10 days, and Patient 3 experienced no effect. Motor blocks may be a useful therapeutic option in chronic treatment-resistant functional dystonia. The treatment effect might be achieved through the experience of normal positioning and functioning of the limb.

Functional seizures: Are they consistent over time?

BACKGROUND

Our previous study showed that functional seizures (FS) are consistent in the same patient during a single video EEG monitoring (VEEG). This study aimed to check whether FS remains consistent across VEEG sessions even after several years.

METHODS

The study evaluated the consistency of FS across different VEEG sessions using five criteria: FS type, the main anatomical region involved (specifically, the body part most affected during the seizure), other involved anatomical regions, frequency of movements, and duration of FS. Consistency levels were categorized as low (one consistent axis), moderate (two consistent axes), and high (three or more consistent axes).

RESULTS

Fourteen patients were included in the final analysis. The mean time between monitoring was 3.8 ± 2.5 years (0.5-8 year). In 13 of 14 patients, the first and second monitoring events were classified into the same FS category. There was consistency in the main anatomical region involved in 9 out of 12 patients with motor FS. In 9 out of 12 patients with motor FS, the other anatomical regions involved were consistent in both sessions. The mean duration of the FS between sessions was inconsistent in most of the patients. Ten patients were classified with high consistency, one patient with moderate consistency, two patients with low consistency, and in one patient, the events were classified as inconsistent.

CONCLUSIONS

Our results show that FS tends to remain consistent in a single patient even after several years, and there is probably no correlation between the degree of consistency and the time between VEEG sessions. These findings have implications for supporting the concept of FS as a consistent phenomenon. Additionally, they may suggest potential avenues for future research to elucidate the origins of FS. Subsequent studies are essential to validate and expand upon these preliminary observations.

Functional Neurological Symptom Disorder: A Continuing Conundrum for the Perioperative Physician

Functional neurological symptom disorder (FNSD) or functional neurological disorder (FND) or conversion disorder, is a syndrome of neurological complications unexplained by neuropathology. The term FNSD or FND is now preferred, as conversion disorder is not an etiologically neutral term and is thus falling from use by researchers and clinicians in the field. We report a case of new-onset postoperative neurological deficit in a patient who had undergone uneventful general anesthesia for a urology procedure. Postoperatively, in the post-anesthesia care unit, the patient was found to be unable to move her upper and lower limbs. Organic pathology was excluded and a diagnosis of FNSD was made. Four weeks after the surgery, the patient was only able to ambulate with the help of a mechanical walker device. It is now suggested that procedures involving anesthesia are relatively common triggers for the development of FNSD. The occurrence of FNSD in the postoperative period is increasingly being attributed to the effects of anesthesia, the hypothesis being that it arises from the abreactive or dissociative effects of anesthetic agents. Another theory is the vulnerability of the anesthetized state which may evoke previous traumatic experiences. Psychiatric co-morbidities such as anxiety and depression may be seen in these patients. Preoperative psychological assessment may help identify patients at risk for FNSD. If postoperative neurological deficit occurs, detailed neurological, metabolic, and psychiatric assessments should be done with FNSD being a diagnosis of exclusion. We present this case to increase awareness regarding this uncommon condition which can cause significant distress to the patient and healthcare team. Management should comprise honest disclosure, reassurance of recovery, and reinforcement of alternative coping strategies. The development of preoperative screening tools may help identify patients at risk for this disorder.