Faculty Bibliography

Despite advancements in the assessment and management of functional neurological disorder (FND), the feasibility of implementing a new standard of care remains unclear. Chart reviews were performed for 100 patients with motor FND to investigate factors related to treatment adherence and clinical improvement over an average follow-up of 7 months. Of 81 patients who returned for follow-up, a history of chronic pain disorder inversely correlated with improvement. Of the 50 individuals newly referred for treatment, adherence correlated with improvement, while having abnormal neuroimaging inversely correlated with improvement. This study supports the feasibility of applying a new standard of care for FND.

OBJECTIVE:Adverse early-life events are predisposing factors for functional neurological disorder (FND) and post-traumatic stress disorder (PTSD). Cingulo-insular regions are implicated in the biology of both conditions and are sites of stress-mediated neuroplasticity. We hypothesised that functional neurological symptoms and the magnitude of childhood abuse would be associated with overlapping anterior cingulate cortex (ACC) and insular volumetric reductions, and that FND and PTSD symptoms would map onto distinct cingulo-insular areas. METHODS:This within-group voxel-based morphometry study probes volumetric associations with self-report measures of functional neurological symptoms, adverse life events and PTSD symptoms in 23 mixed-gender FND patients. Separate secondary analyses were also performed in the subset of 18 women with FND to account for gender-specific effects. RESULTS:Across the entire cohort, there were no statistically significant volumetric associations with self-report measures of functional neurological symptom severity or childhood abuse. In women with FND, however, parallel inverse associations were observed between left anterior insular volume and functional neurological symptoms as measured by the Patient Health Questionnaire-15 and the Screening for Somatoform Symptoms Conversion Disorder subscale. Similar inverse relationships were also appreciated between childhood abuse burden and left anterior insular volume. Across all subjects, PTSD symptom severity was inversely associated with dorsal ACC volume, and the magnitude of lifetime adverse events was inversely associated with left hippocampal volume. CONCLUSIONS:This study reveals distinct cingulo-insular alterations for FND and PTSD symptoms and may advance our understanding of FND. Potential biological convergence between stress-related neuroplasticity, functional neurological symptoms and reduced insular volume was identified.

The assessment of functional neurological disorders (FND) requires an interdisciplinary approach. The authors retrospectively reviewed charts for 100 outpatients with FND and used univariate and regression analyses to investigate neuropsychiatric associations with gender, illness duration, and work disability; secondary analyses evaluated for differences across motor FND subtypes. Men reported higher rates of cognitive complaints and functional weakness, whereas women endorsed increased past physical/sexual trauma. Number of self-reported medication allergies/sensitivities positively correlated with illness duration. Individuals with functional weakness compared with other motor FND subtypes exhibited lower rates of past psychiatric hospitalization and head trauma. This study supports the feasibility of integrating FND research.

BACKGROUND AND OBJECTIVE/OBJECTIVE:Although many patients present with functional neurological symptoms (FNS), few US clinics offer specialized FNS care, and data on clinic attendees remain limited. We determined predictors of initial attendance, symptom burden, and FNS subtype in the first patients referred to our Functional Neurological Disorders Clinic for suspected FNS. METHODS:We reviewed the charts of 62 consecutive patients (46 women, 16 men). Regression analyses investigated predictors of keeping the first scheduled clinic appointment. For the 49 patients who did keep that appointment, regression analyses examined neuropsychiatric factors associated with symptom burden and motor FNS subtypes. RESULTS:The odds of not keeping the first appointment were 10.4 times greater for patients referred from the emergency department than from other sources. The patients who kept their appointment reported a symptom burden that was significantly associated with a past FNS-related emergency department visit and a diagnosis of another medically unexplained somatic syndrome. The number of FNS findings on neurological examination also correlated with a history of an FNS-related emergency department visit. Patients with psychogenic non-epileptic seizures reported cognitive complaints and prior psychiatric hospitalizations significantly more often than did patients with other FNS. One fourth of all patients had two or more motor FNS. CONCLUSIONS:In our FNS cohort, patients were less likely to keep an initial clinic appointment if they were referred from the emergency department than from other sources. Patients with psychogenic non-epileptic seizures were more likely to report cognitive symptoms and past psychiatric hospitalizations than patients with other FNS.

Proopiomelanocortin (POMC) is a multivalent prohormone that can be processed into at least 7 biologically active peptide hormones. Processing can begin in the trans-Golgi network (TGN) and continues in the secretory granules of the regulated secretory pathway (RSP). Sorting of POMC into these granules is a complex process. Previously, a membrane-associated form of carboxypeptidase E (CPE) was shown to bind to POMC and facilitate its trafficking into these granules. More recently, secretogranin III (SgIII) was also found to affect POMC trafficking. Here, we show by RNA silencing that CPE and SgIII play a synergistic role in the trafficking of POMC to granules of the RSP in AtT20 cells. Reduction of either protein resulted in increased constitutive secretion of POMC and chromogranin A, which was increased even further when both proteins were reduced together, indicative of missorting at the TGN. In SgIII-reduced cells, POMC accumulated in a compartment that cofractionated and colocalized with syntaxin 6, a marker of the TGN, on sucrose density gradients and in immunocytochemistry, respectively, indicating an accumulation of this protein in the presumed sorting compartment. Regulated secretion of ACTH, as a measure of sorting and processing of POMC in mature granules, was reduced in the SgIII down-regulated cells but was increased in the CPE down-regulated cells. These results suggest that multiple sorting systems exist, providing redundancy to ensure the important task of continuous and accurate trafficking of prohormones to the granules of the RSP for the production of peptide hormones.