Nonconvulsive Status Epilepticus Research Articles

Ceftazidime-Induced Non-Convulsive Status Epilepticus (NCSE) in a Pediatric Patient with Literature Review.

Cephalosporins are a class of antibiotics routinely prescribed for a variety of pediatric infections. Among uncommon adverse effects, cephalosporins can be neurotoxic and epileptogenic, particularly in patients with reduced renal function. Neurotoxic effects are most frequently observed in adults with impaired renal function, and they have rarely been recorded in children. An 11-year-old boy with chronic renal failure experienced non-convulsive status epilepticus two days after initiating intravenous cefazolin and ceftazidime with a pre-diagnosis of peritonitis. The patient's mental condition reverted to baseline within hours after intravenous antibiotic treatment was discontinued and appropriate antiepileptic and anticonvulsive therapy was started. Providers should investigate cephalosporin-induced non-convulsive status epilepticus clinically and electrophysiologically in any child with renal impairment who demonstrates acute changes in mental status or decreased awareness after initiating intravenous cephalosporins.

Clinical and diagnostic characteristics of Hashimoto’s encephalopathy: a single-center, retrospective study

Abstract Background and purpose Diagnosing Hashimoto’s encephalopathy (HE) is challenging. In contrast to other types of autoimmune encephalitis, HE shows an excellent response to steroid treatment. We aimed to investigate the rates of antithyroid antibodies (ATAs) and probable HE in patients with unexplained mental dysfunction and compare the clinical characteristics between the good- and poor-outcome groups. Methods We retrospectively reviewed the medical records and electroencephalography (EEG) and neuroimaging findings of patients admitted to the Department of Neurology of our hospital from March 1, 2006, to February 28, 2023. Using our proposed diagnostic criteria for probable HE, we compared the clinical characteristics between the good- and poor-outcome groups. We also investigated the rates of ATA positivity and probable HE. Results In total, 198 patients exhibited altered mentation, rapidly progressive cognitive decline, or myoclonus. ATA tests were performed on 86 patients, and the detection rates of ATAs and probable HE were 29.1% and 25.6%, respectively. Of the 22 patients enrolled, the good- and poor-outcome groups comprised 19 and 3 patients, respectively. Clinical seizures occurred in seven patients. Nonconvulsive status epilepticus on EEG was observed in six patients, all of whom were intractable to antiepileptic drugs. Nineteen of 21 patients (90.5%) treated with immunosuppressants showed good outcomes. Conclusions HE is a rare clinical disorder, but not as rare as previously thought. When HE is suspected, steroids should be considered the first-line treatment. Early diagnosis and adequate treatment are critical to achieve good outcomes in HE.

The therapeutic effect of vagus nerve stimulation on super-refractory nonconvulsive status epilepticus

Super refractory status epilepticus (SRSE) is a condition in which status epilepticus persists despite 48 hours of anesthetic treatment. Nonconvulsive status epilepticus (NCSE) is characterized by seizures lasting more than 30 min on an electroencephalogram, with accompanying changes in behavior or consciousness without convulsions. Prompt treatment of NCSE is crucial, as delayed treatment may lead to additional brain damage and progression to convulsive status epilepticus. Although vagus nerve stimulation (VNS) has been approved as an adjunct treatment for drug-resistant epilepsy, it is rarely used to treat refractory status epilepticus. To the best of our knowledge, only two cases of NCSE treated with VNS have been reported to date, and these patients were successfully treated with VNS for NCSE caused by anti-NMDAR encephalitis. We report the case of a patient with posttraumatic epilepsy who developed super refractory-NCSE after convulsive status epilepticus and was successfully treated with VNS.

Enteral Ketamine for Status Epilepticus in Children with Epilepsy

BackgroundApproximately 10% to 20% of children with epilepsy experience status epilepticus (SE), and children with seizure clustering are at higher risk. Ketamine is growing in use for SE. This study examines the efficacy and safety of enteral ketamine in the treatment of convulsive status epilepticus (CSE) characterized by refractory seizure clusters and nonconvulsive status epilepticus (NCSE) in children with epilepsy. MethodsPatient charts were reviewed retrospectively. Children with epilepsy aged one to 21 years presenting in SE and treated with enteral ketamine between September 1, 2021 and September 1, 2022 at a pediatric tertiary care center were identified. Resolution or reduction in seizure frequency within 48 hours, clinical presentation, endotracheal intubation, hospitalization duration, side effects, and readmission were assessed. ResultsNine patients aged two to 21 years were identified. Six patients presented in CSE characterized by recurrent seizures, and three patients presented in NCSE. Five patients had genetic epilepsies, including PCDH19- and MECP2-related epilepsy. Seven patients had resolution or reduction in seizures within 48 hours of ketamine initiation. Two patients were intubated. Hospitalization duration ranged from one to 34 days. Three patients reported side effects. Three patient readmissions with early ketamine treatment had equal or shorter hospitalizations. ConclusionsEnteral ketamine may prove an effective, well-tolerated option for treatment of convulsive and nonconvulsive SE in children with epilepsy, including genetic epilepsies, and may prevent intubation and shorten hospitalization time.

Significance of thalamic hyperperfusion patterns in computed tomography perfusion in patients with nonconvulsive status epilepticus: possible utility in predicting antiseizure medication resistance

Background: This study aimed to determine the characteristics of computed tomography perfusion (CTP) patterns and their utility in predicting antiseizure medication (ASM) resistance in patients with nonconvulsive status epilepticus (NCSE).Methods: We retrospectively reviewed patients diagnosed with NCSE at Inje University Haeundae Paik Hospital Epilepsy Center between March 2015 and March 2022. CTP patterns were analyzed for those patients. A hyperperfusion pattern (HPP) in CTP was defined as a region of both increased cerebral blood flow and cerebral blood volume that did not necessarily follow the vascular territories. The primary endpoint was the responses to ASMs according to CTP patterns.Results: Fourteen (74%) of the 19 included patients met the criteria for definite NCSE, with the remaining 26% showing nonepileptiform activities with fluctuating quasirhythmic delta activities at >0.5 Hz on electroencephalogram. Three of the four patients who had HPPs with thalamic involvement were refractory to ASMs, whereas all eight patients who had HPPs without thalamic involvement were responsive to ASMs (<i>p</i> = 0.018). Although HPPs themselves were not associated with ASM responses, HPPs with thalamic involvement were associated with resistance to ASMs.Conclusions: HPP with thalamic involvement in CTP might be associated with ASM resistance. Therefore, CTP may be useful for predicting ASM resistance in NCSE patients.

Ictal Cotard delusion as a manifestation of nonconvulsive status epilepticus: A case report and commentary.

Psychosis of epileptic origin can present a wide range of cognitive and affective symptoms and is often underrecognized. Usually occurring in the inter- and postictal phase, epileptic psychosis is mostly related to temporal lobe epilepsy. Here, we describe the clinical presentation and diagnostic workup including routine EEG recording and brain MRI of a 63-year-old woman expressing isolated nihilistic delusions comprising belief of being dead and denial of self-existence. EEG showed an ictal pattern fulfilling the Salzburg criteria of nonconvulsive status epilepticus and brain MRI revealed extensive peri-ictal hyperperfusion. Delusional symptoms and EEG abnormalities subsided after acute antiseizure treatment. Our case illustrates how nihilistic delusions can occur as a direct clinical correlate of seizure activity, thereby expanding the spectrum of ictal neuropsychiatric phenomena in temporal lobe epilepsy and highlighting the need to consider an epileptic origin in patients presenting with psychotic symptoms.

Hypocretin-1/orexin-A, sleep and excessive daytime sleepiness in patients with nonconvulsive status epilepticus: A cross-sectional cohort study

Background and objectivesNonconvulsive status epilepticus (NCSE) manifests as a change in mental status without a coma (NCSE proper) or comatose NCSE. Hypocretin-1/orexin-A (H/O) is involved in alertness and sleep maintenance. Sleep impairment and excessive daytime sleepiness (EDS) have a negative impact on cognitive functions and activities of daily living (ADL). MethodsPatients meeting the NCSE criteria underwent cerebrospinal fluid and brain magnetic resonance imaging examinations, polysomnographies (PSG), multiple latency sleep tests (MSLT), and completed Epworth Sleepiness Scale (ESS). Montreal Cognitive Assessment was used to evaluate cognitive functions, and the Barthel Index was used to assess ADL in the acute phase (V1) and three months follow-up (V2). ResultsFrom May 2020 to May 2023, we enrolled 15 patients, eight (53.3 %) women, with a median age of 69 (14) years. The median H/O CSF concentration was 250 (63.6) pg/ml; however, only three CSF samples (20 %) decreased below the borderline concentration of 200 pg/ml. Fourteen out of 15 patients (93.3 %) completed the PSG study. The median of wakefulness after sleep onset was 167 (173.5) min, sleep efficiency (SE) was 62.9 (63) %, sleep latency (SL) was 6 (32) min, REM sleep was 2.85 (7.2) %, and REM first episode latency was 210.5 (196.5) minutes. The medians of the stages N1 NREM were 4.65 (15) %, N2 NREM 68.4 (29.9) %, and N3 NREM 21.8 (35.5) %. MSLT mean latency was 7.7 (12.6) minutes. A significant negative correlation exists between H/O CSF concentrations and the stage N1 NREM (rs = −0.612, p = 0.02), and the proportion of cumulative sleep time with oxygen saturation below 90 % in total sleep time (TST) t90 (rs = −0.57, p = 0.03). MSLT had significant negative correlation with TST (rs = −0.5369, p = 0.0478), with SE (rs = −0.5897, p = 0.0265), with apnea-hypopnea index (rs = −0.7631, p = 0.0002) and with deoxygenation index (rs = −0.8009, p = 0.0006). A positive correlation exists between MSLT and SL (rs = 0.6284, p = 0.0161) and between ESS and t90 (rs = 0.9014, p = 0.0004). The correlation between H/O CSF concentrations and EDS, cognitive performance, and ADL was not proved. ConclusionsPatients after NCSE exhibited sleep impairment and excessive daytime sleepiness. Hypocretin-1/orexin-A concentrations decreased only in 20 % of these cases.

Stimulus-induced arousal with transient electroencephalographic improvement distinguishes nonictal from ictal generalized periodic discharges.

In the case of suspicion of nonconvulsive status epilepticus (NCSE), reactivity on electroencephalograms (EEGs) can provide valuable diagnostic information. Reactivity refers to responses to auditory or somatosensory stimulation, with changes in amplitude and frequency of background activity. Because of self-perpetuating processes and the failure of self-terminating mechanisms, status epilepticus is unlikely to cease when patients spontaneously move, and it cannot typically be stopped by external stimulation (i.e., auditory and tactile stimuli). The defining EEG characteristic of absence status epilepticus is the presence of bilateral, synchronous, symmetric, rhythmic paroxysmal activity that shows little or no reactivity to sensory stimulation. On the other hand, in metabolic/toxic or multifactorial encephalopathies, triphasic waves (TWs) are influenced by the level of vigilance. TWs may be transiently abolished when patients increase their level of alertness from a drowsy/lethargic state to a state of wakefulness. This reactivity is only observed when patients can be aroused by a somatosensory or auditory stimulus. This reactivity tends to disappear with increasing severity of the disease and in comatose patients. In patients without preexisting developmental and epileptic encephalopathy, this pattern of stimulus-induced wakefulness with transient improvement of the EEG is a major criterion in determining that the EEG patterns are not ictal. This criterion of reactivity on EEGs, beyond the classical clinical/EEG criteria of NCSE (Salzburg criteria), should now be systematically added.

Case Series: Risk and Clinical Manifestation of Non-Convulsive Status Epilepticus After Traumatic Brain Injury

Case Series: Risk and Clinical Manifestation of Non-Convulsive Status Epilepticus After Traumatic Brain Injury

Non-convulsive Status Epilepticus due to LGI-1 Encephalitis Presenting as Intermittent Confusion (P6-14.014)

Non-convulsive Status Epilepticus due to LGI-1 Encephalitis Presenting as Intermittent Confusion (P6-14.014)

EEG and acute confusional state at the emergency department

ObjectivesAcute confusional state (ACS) is a common cause of admission to the emergency department (ED). It can be related to numerous etiologies. Electroencephalography (EEG) can show specific abnormalities in cases of non-convulsive status epilepticus (NCSE), or metabolic or toxic encephalopathy. However, up to 80% of patients with a final diagnosis of NCSE have an ACS initially attributed to another cause. The exact place of EEG in the diagnostic work-up remains unclear. MethodsData of consecutive patients admitted to the ED for an ACS in a two-year period and who were referred for an EEG were collected. The initial working diagnosis was based on medical history, clinical, biological and imaging investigations allowing classification into four diagnostic categories. Comparison to the final diagnosis was performed after EEG recordings (and sometimes additional tests) were performed, which allowed the reclassification of some patients from one category to another. ResultsSeventy-five patients (mean age: 71.1 years) were included with the following suspected diagnoses: seizures for 8 (11%), encephalopathy for 14 (19%), other cause for 34 (45%) and unknown for 19 (25%). EEG was recorded after a mean of 1.5 days after symptom onset, and resulted in the reclassification of patients as follows: seizure for 15 (20%), encephalopathy for 15 (20%), other cause for 29 (39%) and unknown cause for 16 (21%). Moreover, ongoing epileptic activity (NCSE or seizure) and interictal epileptiform activity were found in eight (11%) patients initially diagnosed in another category. DiscussionIn our cohort, EEG was a key examination in the management strategy of ACS in 11% of patients admitted to the ED. It resulted in a diagnosis of epilepsy in these patients admitted with unusual confounding presentations.

Cerebral malaria presenting as nonconvulsive status epilepticus: a case report

BackgroundMalaria is an infectious malady caused by Plasmodium parasites, cerebral malaria standing out as one of its most severe complications. Clinical manifestation include elevated body temperature, loss of consciousness, and seizures. However, reports of cerebral malaria presenting as nonconvulsive status epilepticus are extremely rare. The case presented involves psychiatric symptoms, with the electroencephalogram indicated nonconvulsive status epilepticus associated with cerebral malaria.Case presentationA 53-year-old male, was urgently admitted, due to confusion and abnormal behaviour for 10 h. The patient returned to China after developing a fever while working in Tanzania two months ago. The blood smear revealed Plasmodium vivax and Plasmodium falciparum, and he was diagnosed with malaria. He recovered following anti-malarial treatment. After admission, the patient was confused, unable to communicate normally, and unwilling to cooperate with the physical examination. Plasmodium was not found in the blood smear, but the DNA sequence of P. falciparum was discovered using metagenomic next-generation sequencing of cerebrospinal fluid. Brain MRI revealed no significant abnormalities. Continuous electroencephalogram monitoring revealed that the patient had non-convulsive status epilepticus, which was treated with diazepam and levetiracetam. The patient had normal consciousness and behaviour. He received anti-malarial treatment for two weeks and fully recovered.ConclusionsThis case demonstrates that nonconvulsive status epilepticus can be a manifestation of cerebral malaria. It is imperative for attending physicians to heighten vigilance when encountering patients with a history of travel to malaria-endemic regions or a prior malaria infection, especially in the presence of unusual clinical presentations.

Status Epilepticus after mechanical thrombectomy: The role of early EEG assessment in Stroke Unit, clinical and radiological prognostication

BackgroundConvulsive (CSE) and non-convulsive (NCSE) Status Epilepticus are a complication in 0.2–0.3% ischemic strokes. Large stroke and cortical involvement are the main risk factors for developing SE. This study evaluates the prevalence of SE in patients treated with endovascular thrombectomy (EVT) through EEG recording within 72- h from admission. Moreover, we compared clinical, radiological, and outcome measures in SE and no-SE patients. Materials and MethodsWe collected retrospectively demographical and clinical characteristics of acute ischemic stroke patients who underwent EVT, admitted in the Stroke Unit (SU) of the University Hospital of Trieste between January 2018 and March 2020 who underwent EEG recording within 72- h from the symptoms’ onset. ResultsOut of 247 EVT patients, 138 met the inclusion criteria, of whom 9 (6.5%) showed SE with median onset time of 1 day (IQR 1–2). No difference was found between the two groups as for age, sex, risk factors, grade of recanalization, etiology of stroke, and closed vessel. The no-SE group presented higher NIHSS improvement rate (p=0.025) compared to the SE group. The sum of the lobes involved in the ischemic lesion was significantly higher in SE group (p=0.048). ConclusionSE after EVT in large strokes is a non-rare complication, with most being NCSE. Performing a rapid EEG assessment in a Stroke Unit setting may allow for a prompt recognition and treatment of SE in the acute/hyper-acute phase. SE may be correlated with worse clinical outcomes in patients with large vessel occlusion.

The diagnostic yield of a 2-h versus a 30-min electroencephalogram for patients with altered mental status in neurological intensive care unit

BackgroundThe continuous electroencephalogram (cEEG) monitoring is recommended for critical ill patients with altered mental status, The cEEG detects seizure activity and nonconvulsive status epilepticus (NCSE) more efficiently than routine electroencephalogram (rEEG). Yet, cEEG is not widely available in many neurological intensive care units (NICU) in limited resource countries. Ideal study duration, and whether cEEG is useful and cost-effective in terms of patient outcome compared to (rEEG), is still questions under research. The main objective in our study was the relative diagnostic yield of the 2 h, prolonged EEG recording, compared to the 30-min rEEG recording in the NICU.ResultsThere was no significant diagnostic yield for the 2-h electroencephalogram (EEG) over the 30-min EEG for patient with altered mental status in the NICU. Being with altered mental state in an NICU carries a poor outcome, we found that death occurred in 68.9% of patients. Acute ischemic stroke is the most common cause of altered mental status in NICU by about 53.3% of patients. Less than half of the patients (42.2%) were receiving anti-seizure medications (ASM).ConclusionsAs long as the cEEG is not available in the NICU, the 30-min EEG has a good diagnostic yield and it is almost equivalent to the prolonged 2-h EEG, and if the EEG is recommended for a longer duration, we recommend a long-term EEG more than 2 h.

The risk of unprovoked seizure occurrence after status epilepticus in adults.

Status epilepticus (SE) may lead to long-term consequences. This study evaluated the risk and predictors of seizure occurrence after SE, with a focus on SE due to acute symptomatic etiologies. Prospectively collected data about adults surviving a first non-hypoxic SE were reviewed. The outcome was the occurrence of unprovoked seizures during the follow-up. Kaplan-Meier survival curve analysis and log-rank test were used to analyze the time to seizure occurrence and determine the statistical significance between etiological groups. Three subcategories within acute etiology were considered according to the presence of the following: (1) structural lesion (acute-primary); (2) brain involvement during systemic disorders (acute-secondary); and (3) drug or alcohol intoxication/withdrawal (acute-toxic). Cox proportional hazards model was adopted to estimate hazard ratios (HRs) with the 95% confidence intervals (CIs). Two hundreds fifty-seven individuals were included. Fifty-four subjects (21.0%) developed seizures after a median of 9.9 (interquartile range 4.3-21.7) months after SE. The estimated 1-, 2-, and 5-year rates of seizure occurrence according to acute SE etiologies were 19.4%, 23.4%, and 30.1%, respectively, for acute-primary central nervous system (CNS) pathology; 2.2%, 2.2%, and 8.7%, respectively, for acute-secondary CNS pathology; and 0%, 9.1%, and 9.1%, respectively, for acute-toxic causes. Five-year rates of seizure occurrence for non-acute SE causes were 33.9% for remote, 65.7% for progressive, and 25.9% for unknown etiologies. In multivariate Cox regression model, progressive etiology (adjusted HR [adjHR] 2.27, 95% CI 1.12-4.58), SE with prominent motor phenomena evolving in non-convulsive SE (adjHR 3.17, 95% CI 1.38-7.25), and non-convulsive SE (adjHR 2.38, 95% CI 1.16-4.90) were independently associated with higher hazards of unprovoked seizures. Older people (adjHR .98, 95% CI .96-.99) and people with SE due to acute-secondary CNS pathology (adjHR .18, 95% CI .04-.82) were at decreased risk of seizure occurrence. SE carries a risk of subsequent seizures. Both the underlying cause and epileptogenic effects of SE are likely to contribute.

Non-hepatic Hyperammonemia with Loading Dose of Perampanel in a Case of CNS Lupus Presenting with Non-Convulsive Status Epilepticus

Non-hepatic Hyperammonemia with Loading Dose of Perampanel in a Case of CNS Lupus Presenting with Non-Convulsive Status Epilepticus

Cefepime-induced non-convulsive status epilepticus

Cefepime-induced non-convulsive status epilepticus

Remote seizures and drug-resistant epilepsy after a first status epilepticus in adults.

Long-term consequences after status epilepticus (SE) represent an unsettled issue. We investigated the incidence of remote unprovoked seizures (RS) and drug-resistant epilepsy (DRE) in a cohort of first-ever SE survivors. A retrospective, observational, and monocentric study was conducted on adult patients (age ≥ 14 years) with first SE who were consecutively admitted to the Modena Academic Hospital, Italy (September 2013-March 2022). Kaplan-Meier survival analyses were used to calculate the probability of seizure freedom following the index event, whereas Cox proportional hazard regression models were used to identify outcome predictors. A total of 279 patients were included, 57 of whom (20.4%) developed RS (mean follow-up = 32.4 months). Cumulative probability of seizure freedom was 85%, 78%, and 68% respectively at 12 months, 2 years, and 5 years. In 45 of 57 patients (81%), the first relapse occurred within 2 years after SE. The risk of RS was higher in the case of structural brain damage (hazard ratio [HR] = 2.1, 95% confidence interval [CI] = 1.06-4.01), progressive symptomatic etiology (HR = 2.7, 95% CI = 1.44-5.16), and occurrence of nonconvulsive evolution in the semiological sequence of SE (HR = 2.9, 95% CI = 1.37-6.37). Eighteen of 57 patients (32%) developed DRE; the risk was higher in the case of super-refractory (p = 0.006) and non-convulsive SE evolution (p = 0.008). The overall risk of RS was moderate, temporally confined within 2 years after the index event, and driven by specific etiologies and SE semiology. Treatment super-refractoriness and non-convulsive SE evolution were associated with DRE development.

Sustained effort network for treatment of status epilepticus/European academy of neurology registry on adult refractory status epilepticus (SENSE-II/AROUSE)

BackgroundStatus Epilepticus (SE) is a common neurological emergency associated with a high rate of functional decline and mortality. Large randomized trials have addressed the early phases of treatment for convulsive SE. However, evidence regarding third-line anesthetic treatment and the treatment of nonconvulsive status epilepticus (NCSE) is scarce. One trial addressing management of refractory SE with deep general anesthesia was terminated early due to insufficient recruitment. Multicenter prospective registries, including the Sustained Effort Network for treatment of Status Epilepticus (SENSE), have shed some light on these questions, but many answers are still lacking, such as the influence exerted by distinct EEG patterns in NCSE on the outcome. We therefore initiated a new prospective multicenter observational registry to collect clinical and EEG data that combined may further help in clinical decision-making and defining SE.MethodsSustained effort network for treatment of status epilepticus/European Academy of Neurology Registry on refractory Status Epilepticus (SENSE-II/AROUSE) is a prospective, multicenter registry for patients treated for SE. The primary objectives are to document patient and SE characteristics, treatment modalities, EEG, neuroimaging data, and outcome of consecutive adults admitted for SE treatment in each of the participating centers and to identify factors associated with outcome and refractoriness. To reach sufficient statistical power for multivariate analysis, a cohort size of 3000 patients is targeted.DiscussionThe data collected for the registry will provide both valuable EEG data and information about specific treatment steps in different patient groups with SE. Eventually, the data will support clinical decision-making and may further guide the planning of clinical trials. Finally, it could help to redefine NCSE and its management.Trial registrationNCT number: NCT05839418.

Nonconvulsive status epilepticus in patients with acute subarachnoid hemorrhage is associated with negative arterial spin labeling on peri-ictal magnetic resonance images

PurposeNon-convulsive status epilepticus (NCSE) is characterized by repetitive or continuous seizures without convulsions. Arterial spin labeling (ASL) is useful for assessing hyperperfusion due to neurovascular unit coupling in patients with NCSE; subarachnoid hemorrhage (SAH) impairs the neurovascular unit. We hypothesized that the sensitivity of ASL in detecting NCSE is low in patients with SAH during the acute phase. MethodsBased on ASL findings obtained within 48 h after the clinical suspicion of focal-onset NCSE, we divided 34 patients into ASL-negative (no hyperperfusion; n = 10) and ASL-positive (confirmed hyperperfusion; n = 24) groups. We further divided the two groups according to the NCSE etiology: patients who were diagnosed with NCSE within 14 days after SAH onset (acute SAH, n = 11) and patients with NCSE due to factors other acute SAH (n = 23) and compared their characteristics. ResultsIn 10 of the 34 patients (29.4 %) the ASL findings were normal. The rate of acute SAH was significantly higher in ASL-negative- (n = 8, 80.0 %) than ASL-positive patients (n = 3, 12.5 %). The rate of patients in aphasic status was significantly lower in ASL-negative patients (n = 1, 10 %) than in ASL-positive patients (n = 12, 50.0 %). ConclusionNormal ASL findings alone should not be used to exclude a diagnosis of NCSE particularly in patients in the acute phase of SAH with deterioration or no improvement in consciousness.