Cauda equina syndrome.

Aims: Patients with cauda equina syndrome (CES) require emergency imaging and surgical decompression. The severity and type of symptoms may influence the timing of imaging and surgery, and help predict the patient's prognosis. Categories of CES attempt to group patients for management and prognostication purposes. We aimed in this study to assess the inter-rater reliability of dividing patients with CES into categories to assess whether they can be reliably applied in clinical practice and in research. Methods: A literature review was undertaken to identify published descriptions of categories of CES. A total of 100 real anonymized clinical vignettes of patients diagnosed with CES from the Understanding Cauda Equina Syndrome (UCES) study were reviewed by consultant spinal surgeons, neurosurgical registrars, and medical students. All were provided with published category definitions and asked to decide whether each patient had 'suspected CES'; 'early CES'; 'incomplete CES'; or 'CES with urinary retention'. Inter-rater agreement was assessed for all categories, for all raters, and for each group of raters using Fleiss's kappa. Results: Each of the 100 participants were rated by four medical students, five neurosurgical registrars, and four consultant spinal surgeons. No groups achieved reasonable inter-rater agreement for any of the categories. CES with retention versus all other categories had the highest inter-rater agreement (kappa 0.34 (95% confidence interval 0.27 to 0.31); minimal agreement). There was no improvement in inter-rater agreement with clinical experience. Across all categories, registrars agreed with each other most often (kappa 0.41), followed by medical students (kappa 0.39). Consultant spinal surgeons had the lowest inter-rater agreement (kappa 0.17). Conclusion: Inter-rater agreement for categorizing CES is low among clinicians who regularly manage these patients. CES categories should be used with caution in clinical practice and research studies, as groups may be heterogenous and not comparable.

Testing the 'seizure scaffold': What can experimental simulation tell us about functional seizures?

INTRODUCTION: It has been suggested for over 100 years that patterns of neurological symptoms and signs in functional neurological disorders may be shaped at a neural level by underlying ideas or preconceptions how neurological symptoms present. This study used experimental simulation to probe ideas about seizures in healthy volunteers, with a view to compare with features commonly observed in functional and epileptic seizure disorders. METHODS: Sixty healthy volunteers were instructed to simulate an epileptic seizure. The episodes were video-recorded and assessed by three qualified markers for the presence of clinical features commonly observed in functional seizures (FS), epileptic seizures, and syncope. RESULTS: Simulated seizures were hyperkinetic (83%), hypokinetic (7%), or staring (10%). Fifty-two percent had their eyes open and 45% eyes closed. Tremor was observed in 70%, while clonic jerking was only present in 17%. The majority of volunteers maintained a normal or floppy body posture. Head shaking side-to-side was observed in 38%, while guttural cries, stertorous breathing, tearfulness, and hyperventilation were absent in all volunteers. DISCUSSION: Our results suggest that simulated seizures not only resemble FS more closely than epileptic seizures but also show some important differences. Subjective seizure experiences in people with FS, not captured by this experimental simulation, remain a core determinant of semiology.