Miguel A. Hernández-Hernández

Nonconvulsive status epilepticus in adults: Electroclinical differences between proper and comatose forms☆

OBJECTIVE Nonconvulsive status epilepticus (NCSE) represents an important percentage of status epilepticus in adults, but detailed studies of both NCSE proper and comatose NCSE are lacking. We retrospectively analyzed a prospectively collected series of 50 adult patients with a diagnosis of NCSE whose electroencephalograms (EEGs) have been interpreted for a period of 10 years by the same investigator. METHODS Two groups, NCSE proper and comatose NCSE were considered. All clinical, EEGs, neuroimaging data, antiepileptic treatment and outcome were analyzed. RESULTS Thirty-two patients (64%) had NCSE proper and 18 patients (36%) comatose NCSE. The mean age was 56 years (range 19-89 years). Fourteen (44%) were diagnosed with absence status epilepticus (ASE), one had simple partial status epilepticus (SPSE) and 17 (53%) had complex partial status epilepticus (CPSE). The mean episode duration (33.2±13.9 versus 60.6±34.0), mean number of antiepileptic drugs (AEDs) (1.46±0.5 versus 2.77±1.39) and neuroimaging anomalies (50% versus 16%) was significantly greater in the partial/focal NCSE proper subgroup than in the ASE subgroup. The mean age (56.0±19.9 versus 69.4±12.1), number of elderly individuals (46% versus 77%), mean duration of the episode (49.1±30.4 versus 153.3±142.6), mortality rate (6% versus 61%) and admission at ICU (18% versus 83%) was significantly higher in the comatose NCSE group than in the NCSE proper group (p<.05). Conversely, a previous history of chronic epilepsy was significantly more frequent (62% versus 5.6%) in the NCSE proper group. The mean duration of comatose NCSE was significantly greater in the surviving subgroup (102.5±29.1 versus 233.1±65.3; p<.05). CONCLUSIONS Our study demonstrates that there are sufficient differences regarding age of onset, history of previous epilepsy, episode duration, mortality rate and clinical presentation between NCSE proper and comatose NCSE to recommend adoption in clinical practice. These results should be taken into account when developing future classifications and therapeutic trials on NCSE. SIGNIFICANCE A distinction between NCSE proper (ambulatory forms of NCSE) and comatose NCSE is useful in the clinical practice and, therefore, it should taken in account in the design of future investigations on this heterogeneous epileptic condition.

Utility of bilateral Bispectral index (BIS) monitoring in a comatose patient with focal nonconvulsive status epilepticus.

We report the case of a patient with an extensive right cerebral hematoma complicated by focal nonconvulsive status epilepticus (NCSE) in whom the use of the new bilateral BIS-Vista™ monitor was helpful in managing profound sedation and antiepileptic treatment in the absence of continuous EEG monitoring (CEEG). The analysis of color density spectral array (CDSA) showed stereotyped changes indicative of recurrent focal nonconvulsive seizures (NCSz) and NCSE. We noted a close correlation between NCSz and BIS value changes. EEGs during working hours always confirmed the persistence of focal NCSE. After several days of sedation, CDSA disclosed a gradual resolution of NCSE that was also confirmed by electroencephalography. The patient died of cardiorespiratory complications a few days later.

New understanding of nonconvulsive status epilepticus in adults: treatments and challenges.

Nonconvulsive status epilepticus (NCSE) in adults represents a constellation of conditions producing ongoing ictal impairment with myriad clinical presentations. These may vary from minimal obtundation, to psychosis to coma for which electroencephalography is essential to diagnosis. Treatment is highly variable and is tailored to the level of consciousness, probable outcome and underlying etiology. There is a new and emerging understanding of the nature of NCSE, its classification and the challenges in treatment. The aim of this article is to review the classic and most recent literature on NCSE in adults focusing attention on the clinical settings in which NCSE frequently occurs, in order to improve awareness of the issues involved in electroclinical diagnosis, treatment and prognostication.

Non confirmatory electroencephalography in patients meeting clinical criteria for brain death: Scenario and impact on organ donation

OBJECTIVE To describe the causes and outcome of adult patients with preserved electroencephalographic activity despite clinical findings suggesting brain death (BD), and its impact on organ donation. METHODS Retrospective study of the clinical and electroencephalography (EEG) data of all adult patients admitted to our hospital between January 2001 and December 2011 in whom a comprehensive clinical diagnosis of BD was reached following absence of brainstem reflexes and confirmatory apnea tests, were obtained. All patients with clinical findings suggesting BD and an EEG showing brain activity were selected for the analysis. We calculated the brain death interval (BDI) as the time between the first complete clinical examination and confirmatory ancillary test, or the time between the first and second complete clinical examination for BD, in order to analyze the impact on family consent for organ donation. RESULTS A complete clinical examination and EEG were diagnostic in 289 patients. In 279 (96.5%), the first EEG showed electrocerebral inactivity corroborating the clinical findings of BD. The mean BDI in this group was 4.2 ± 5.8h (median; 1.8[1.0-3.5]). This value was significantly lower than in the group in which only two full clinical evaluations were performed (p<0.0001). In 10 out 289 (3.5%), the first EEG showed at least some brain activity. The mean BDI in this group was 27.2 ± 13.8h (median; 22.9 [19.1-31.2]). In two cases, a third EEG was necessary before obtaining electrocerebral inactivity. A BDI>6h, was positively associated with a family refusal for organ donation (p=0.02). CONCLUSIONS The rate of EEGs with electrocerebral activity despite clinical findings suggesting BD was only 3.5%. It occurred most frequently with severe brainstem damage. Although in this small percentage of patients, BD diagnosis was notably delayed, in the great majority of cases the use of EEG shortened the BDI. In our series, a BD diagnosis delay >6h negatively affected consent for organ donation. SIGNIFICANCE The use of EEG can decrease the time interval for brain death diagnosis.

Usefulness of bilateral bispectral index (BIS) monitoring in a comatose patient with myoclonic status epilepticus secondary to cefepime

BackgroundStatus epilepticus, particularly non-convulsive status epilepticus (NCSE), is a frequent complication in patients with altered renal function receiving treatment with intravenous cefepime. To the best of our knowledge, we report the first case, illustrated by video-EEG, of a critically ill patient receiving treatment with cefepime who developed an episode of confirmed symptomatic myoclonic status epilepticus (MSE).MethodsCase report and video-EEG.ResultsA 60-year-old man, who had received a liver transplant due to alcoholic cirrhosis one year ago, was admitted to our intensive care unit due to septic shock. Computed tomography revealed a prostatic abscess as cause of his sepsis. On Day 27, a respiratory infection due to Pseudomona aeruginosa was diagnosed, and treatment with intravenous cefepime (2 g/8 hours) was initiated. On Day 32, his mental status deteriorated and he developed inattention, a reduced level of consciousness, and multifocal and generalised continuous myoclonic jerks. A video-EEG study was compatible with the diagnosis of symptomatic MSE. On Day 35, cefepime was stopped and general anaesthesia with midazolam was started in order to achieve a faster clinical improvement. We used the BIS-Vista™ monitor to guide general anaesthesia and detect potential episodes of NCSE. On Day 40, an EEG confirmed the existence of moderate diffuse encephalopathy. Finally, the patient died as a consequence of severe heart failure.ConclusionsCefepime may be a cause of MSE in non-anoxic comatose patients. Clinicians should be aware of this possibility when evaluating comatose patients on cephalosporin therapy in order to establish a correct diagnostic approach and accurate prognosis.

Ambulatory non-convulsive status epilepticus evolving into a malignant form

We retrospectively analysed the clinical characteristics, electroencephalogram (EEG) records, brain magnetic resonance imaging (MRI) scans, antiepileptic therapy and prognosis of a case series with ambulatory non-convulsive status epilepticus (NCSE) which evolved into a malignant form (mNCSE). mNCSE was defined as NCSE that continues or recurs five days or more after the onset of general anaesthesia, including those cases where NCSE recurs upon reduction or withdrawal of anaesthetic therapy. Four women and two men were studied. The mean age was 42.8 years (range: 19–63 years). Two of six patients had a previous diagnosis of epilepsy. Four patients died. Two patients had a good outcome with return to consciousness and activities of daily life, and one of these subjects developed temporal lobe epilepsy. In four patients, the cause of mNCSE was encephalitis. Clinical presentation was complex partial status epilepticus (CPSE) in three patients and generalised NCSE (GNCSE) in the other three. Two of the latter had encephalitis and one was diagnosed with progressive myoclonus epilepsy (PME) of Lafora type. The mean duration of the NCSE episodewas 47.5 days (range: 9–139 days; SD: 53.1). In three patients, continuous or rhythmic focal epileptiform discharges were the EEG pattern at onset. In the other three, continuous rhythmic generalised spike-wave, polyspikewave or sharp slow-wave complexes were observed. Antiepileptic treatment was heterogeneous and patients were treated with an average of 6.0 AEDs (range: 3–10; SD: 3.0). In summary, mNCSE is a severe epileptic condition that occurs often in the context of encephalitis or pre-existing epilepsy. Both CPSE and GNCSE may occur. Although high mortality is associated with mNCSE, some patients may survive with normal or good recovery.

Color density spectral array of bilateral bispectral index system: Electroencephalographic correlate in comatose patients with nonconvulsive status epilepticus

PURPOSE to describe the characteristics of the color density spectral array (CDSA) of bilateral bispectral index (b-BIS) monitoring system in patients with comatose nonconvulsive status epilepticus (NCSE). We hypothesized that CDSA could be helpful for monitoring NCSE in critically subjects if continuous EEG (cEEG) is not available. METHODS we retrospectively analyzed comatose patients admitted to our neurological intensive care unit (NICU) from 2011 to 2014 with a diagnosis of definitive NCSE that underwent b-BIS monitoring for at least 24h to guide anesthetic sedation. Clinical, electroencephalography and neuroimaging findings were analyzed. Moreover, all parameters from the b-BIS data including the CDSA were reviewed during periods of NCSE (NCSE pattern) and profound sedation (sedation pattern). RESULTS 15 NCSE patients were included. The delay from the diagnosis of NCSE to the onset of b-BIS monitoring was 8 (0.5-31)h and total time of b-BIS monitoring 7.8±6.5 days. CDSA during NCSE pattern was characterized by continuous or intermittent red and dark red tones, spectral edge frequency (SEF) in the delta-theta range, with or without asymmetry and BIS number trend with significant variability. In contrast, CDSA during sedation revealed predominance of orange, yellow, green and occasionally blue tones, SEF in the alpha-beta range, absence of asymmetry and stability of BIS number. CONCLUSIONS b-BIS monitoring system and, in particular, CDSA used by nonexpert NICU personnel may be helpful to follow-up episodes of NCSE, to detect recurrences of nonconvulsive seizures (NCSzs), and to monitor profound anesthetic therapy in comatose patients when cEEG is not available.

Subclinical focal seizures as a sign of progression in gliomas

BACKGROUND Subclinical seizures are ictal electrographic discharges lacking signs of clinical seizures, behavioural alteration or subjective symptoms. The diagnosis and detection of this type of non-convulsive seizures remain challenging, and information is scarce regarding this electroclinical picture in subjects with gliomas. The aim of this report is to describe two patients with gliomas who, after treatment with surgery and radiotherapy, exhibited subclinical seizures on video-EEG monitoring, as a manifestation of recurrence or progression of their brain tumour. METHODS Case report and video-EEG monitoring analysis. RESULTS Two patients with gliomas were admitted to our neurosurgical unit after a generalized tonic-clonic seizure. Brain MRI revealed a recurrence of their tumour. The use of video-EEG monitoring allowed the detection and characterization of subclinical seizures in both patients that otherwise would have gone undetected. In both cases, subclinical seizures arose from the frontal lobe and were not associated with motor manifestations or subjective symptoms. CONCLUSIONS We emphasize that the existence of subclinical seizures in patients with gliomas is likely to be underestimated, and can occur in advanced progressive tumours. It is important to carry out continuous video-EEG monitoring in brain tumour patients who have had recent clinical seizures in order to be able to detect subclinical seizures and make appropriate diagnosis.

Acute Stimulus-Sensitive Postanoxic Myoclonus The Importance of Sensory Stimulation in Comatose Patients

We describe the case of a 69-year-old woman admitted to our intensive care unit (ICU) after 20 minutes of resuscitation from acute cardiopulmonary arrest. The patient developed a stimulus-sensitive postanoxic myoclonus in the following hours. The electroencephalogram (EEG) showed diffuse bursts of sharp activity against a completely suppressed background. This case report highlights the importance of carrying out a protocol of multiple and multimodal sensory stimulation when recording an EEG in comatose patients admitted to the ICU.

Postanoxic alpha, theta or alpha-theta coma: Clinical setting and neurological outcome

AIM The aim of this study was to determine the prognosis of 26 consecutive adults with alpha coma (AC), theta coma (TC) or alpha-theta coma (ATC) following CRA and to describe the clinical setting and EEG features of these patients. METHODS We retrospective analyzed a prospectively collected cohort of adult patients diagnosed as having AC, TC or ATC after CRA between January 2008 and June 2016. None of patients included in this analysis underwent therapeutic hypothermia (TH). Neurological outcome was expressed as the best score 6 months after CRA using the five-point Glasgow-Pisttsburgh Cerebral Performance Categories (CPC) RESULTS: Twenty-six patients were identified with a diagnosis of postanoxic AC, TC or ATC coma. There were 20 (77%) men and 6 (23%) women. The mean age was 63 ± 16 years. The most frequent EEG pattern was TC (21 patients, 80%), followed by AC (3 patients, 12%) and ATC (2 patients, 8%). The cardiac rhythm as primary origin of the CRA was ventricular fibrillation (VF) in 16 patients (61.5%), asystole in 8 patients (34.6%) and ventricular tachycardia (VT) in one patient (3.8%). The presence of EEG reactivity was present in 8 patients (30%). The mortality rate was 85%. Of the 4 surviving patients, two (3.8%) had moderate disability (CPC 2), one (3.8%) had severe disability (CPC 3) and one (3.8%) reached a good recovery. The age was significantly lower in survivors 46.2 ± 10.8 versus nonsurvivors 63.3 ± 15.5 (p = 0.04). There was increased association of EEG reactivity with survival (p = 0.07). CONCLUSION Hypoxic-ischemic AC, TC and ATC are associated with a poor prognosis and a high rate of mortality. In younger patients with AC, TC and ATC and incomplete forms showing reactivity on the EEG, there is a greater probability of clinical recovery.