Postictal serum creatine kinase for the differential diagnosis of epileptic seizures and psychogenic non-epileptic seizures: a systematic review.

The aim of this review was to evaluate the sensitivity and specificity of postictal creatine kinase (CK) levels in the differential diagnosis of epileptic seizures (ES) and psychogenic non-epileptic seizures (PNES). A systematic search was conducted for studies that evaluated postictal CK levels in patients with ES (all types) and PNES. Sensitivity and specificity with 95 % confidence intervals were determined for each study, taking into account: (a) the upper limits adopted; and (b) the 95.7th percentile values, which are recently proposed practical upper reference limits for CK activity. Four studies, comprising a total of 343 events (248 ES and 95 PNES), were available for analysis. Most patients (47/78, 60 %) with ES considered had primarily or secondarily generalized tonic–clonic seizures. The sensitivity of increased postictal CK levels for ES ranged from 14.6 to 87.5, whereas specificity ranged from 85.0 to 100.0. At the 95.7th percentile threshold, sensitivity ranged from 14.6 to 62.5 and specificity was 100.0. The limited number of studies available, their small sample size, and lack of individual event data prevented further stratification analysis by seizure type. Despite the clinical heterogeneity and the limitations of the included studies, increased postictal CK levels are highly specific for the diagnosis of ES, although no definite conclusion on its role in differentiating between convulsive and non-convulsive ES can be drawn. Postictal serum CK levels can provide valuable retrospective information at the later stages of the differential diagnosis of ES and PNES. Due to low sensitivity, normal postictal CK levels do not exclude ES

Spectral analysis of cardiovascular responses in POTS

The inability to remain upright without orthostatic hypotension is the typical disabling symptom of Postural Orthostatic Tachycardia Syndrome (POTS), attributed either to the central hyperadrenergic outflow or to the compensatory mechanism after legs and splanchnic blood vessels denervation. To verify this second hypothesis we analyzed the neural autonomic responses to different conditions. 10 patients with POTS and 10 controls were investigated with power spectral analysis of the blood pressure and heart rate variability, in resting condition and during a period of 30 min of head \u2013 up tilt test to 60\ub0. The difference between the two conditions was tested using the Wilcoxon signed rank test. No evidence of sympathetic cholinergic and adrenergic failure was found. The most significant and common finding of patients with POTS was a marked increase of the LF/HF ratio in the power spectrum of the R\u2013R interval in the head \u2013 up tilt compared to the reduced values in supine. We did not find an exaggerated pressure response to the Valsalva manoeuvre, but a redistribution of blood flow, due to regional autonomic denervation, was excluded by the preserved increase of blood pressure response during the same test

Heart rate variability in patients with spinal cord injuries

In spinal cord injury both the level and the extension of the lesions have been related to different response to tilting in Low Frequency (LF) and High Frequency (HF) oscillations of heart rate. To understand the role of sympatho\u2013vagal interaction in such patients, we tried to evaluate, using the LF/HF ratio, the residual possibility in maintaining the cardiovascular homeostasis. 9 subjects with different outcome of traumatic (4) and inflammatory (5) spinal cord involvement, with lesion between C6 and T10, were investigated with power spectral analysis of the blood pressure and heart rate variability in resting condition and during a period of head \u2013 up tilt test. The difference between the two conditions was tested using the Wilcoxon signed rank test. In patients with complete ASIA A lesion, the relatively preserved LF activity in resting condition did not increase during tilting, with a parallel decrease of LF/HF ratio. In patients with incomplete lesion (ASIA B, C, D), the LF power of R\u2013R interval showed an inverse relation with the level of the lesion. The LF/HF ratio was partially maintained due to the concomitant adapting HF activity permitting an efficient sympatho\u2013vagal balance

Continuous EEG-fMRI in pre-surgical evaluation of a patient with symptomatic seizures: bold activation linked to interictal epileptic discharges caused by cavernoma

10We used continuous electroencephalography-functional magnetic resonance imaging (EEG-fMRI) to identify the linkage between the “epileptogenic” and the “irritative” area in a patient with symptomatic epilepsy (cavernoma, previously diagnosed and surgically treated), i.e. a patient with a well known “epileptogenic area”, and to increase the possibility of a non invasive pre-surgical evaluation of drug-resistant epilepsies. A compatible MRI system was used (EEG with 29 scalp electrodes and two electrodes for ECG and EMG) and signals were recorded with a 1.5 Tesla MRI scanner. After the recording session and MRI artifact removal, EEG data were analyzed offline and used as paradigms in fMRI study. Activation (EEG sequences with interictal slow-spiked-wave activity) and rest (sequences of normal EEG) conditions were compared to identify the potential resulting focal increase in BOLD signal and to consider if this is spatially linked to the interictal focus used as a paradigm and to the lesion. We noted an increase in the BOLD signal in the left neocortical temporal region, laterally and posteriorly to the poro-encephalic cavity (residual of cavernoma previously removed), that is around the “epileptogenic area”. In our study “epileptogenic” and “irritative” areas were connected with each other. Combined EEG-fMRI may become routine in clinical practice for a better identification of an irritative and lesional focus in patients with symptomatic drug-resistant epilepsy.nonenoneAvesani M; Formaggio E; Milanese F; Baraldo A; Gasparini A; Cerini R; Bongiovanni LG; Pozzi Mucelli R; Fiaschi A; Manganotti PAvesani, M; Formaggio, E; Milanese, F; Baraldo, A; Gasparini, A; Cerini, R; Bongiovanni, Lg; POZZI MUCELLI, Roberto; Fiaschi, A; Manganotti, Paol

CEREBRAL PERFUSION ALTERATIONS IN EPILEPTIC PATIENTS DURING PERI-ICTAL AND POST-ICTAL PHASE: PASL VS DSC-MRI.

Non-invasive pulsed arterial spin labeling (PASL) MRI is a method to study brain perfusion that does not require the administration of a contrast agent, which makes it a valuable diagnostic tool as it reduces cost and side effects. The purpose of the present study was to establish the viability of PASL as an alternative to dynamic susceptibility contrast (DSC-MRI) and other perfusion imaging methods in characterizing changes in perfusion patterns caused by seizures in epileptic patients. We evaluated 19 patients with PASL. Of these, the 9 affected by high-frequency seizures were observed during the peri-ictal period (within 5hours since the last seizure), while the 10 patients affected by low-frequency seizures were observed in the post-ictal period. For comparison, 17/19 patients were also evaluated with DSC-MRI and CBF/CBV. PASL imaging showed focal vascular changes, which allowed the classification of patients in three categories: 8 patients characterized by increased perfusion, 4 patients with normal perfusion and 7 patients with decreased perfusion. PASL perfusion imaging findings were comparable to those obtained by DSC-MRI. Since PASL is a) sensitive to vascular alterations induced by epileptic seizures, b) comparable to DSC-MRI for detecting perfusion asymmetries, c) potentially capable of detecting time-related perfusion changes, it can be recommended for repeated evaluations, to identify the epileptic focus, and in follow-up and/or therapy-response assessment

Cerbral perfusion alterations in epileptic patients during peri-ictal and post-ictal phase: PASL vs DSC-MRI.

10noneFrancesca B. Pizzini; Paolo Farace; Paolo Manganotti; Giada Zoccatelli; Luig G. bongiovanni; Xavier Golay; Alberto Beltramenllo; Antonio Osculati; Giuseppe Bertini; Paolo F. Fabene.Francesca B., Pizzini; Paolo, Farace; Paolo, Manganotti; Giada, Zoccatelli; Luig G., Bongiovanni; Xavier, Golay; Alberto, Beltramenllo; Osculati, ANTONIO MARCO MARIA; Giuseppe, Bertini; Paolo F., Faben