Decerebrate posturing misinterpreted as seizure activity

Bilateral tonic seizures vs. bilateral tonic events in critically ill patients: differences in semiology

PURPOSE

Our primary aim was to analyze bilateral epileptic tonic seizures (ETS) and bilateral non-epileptic tonic events (NTE) in critically ill patients. Our secondary aim was to analyze ETS per their epileptogenic zone.

METHODS

We performed a retrospective analysis of clinical signs in patients with bilateral ETS and NTE. Two authors independently reviewed 34 videos of ETS in 34 patients and 15 videos of NTEs in 15 patients. Initial screening and review was performed in an unblinded manner. Subsequently, the semiology was characterized independently and blindly by a co-author. Statistical analysis was conducted using Bonferroni correction and two-tailed Fischer exact test. Positive predictive value (PPV) was calculated for all signs. Cluster analysis of signs with a PPV >80% was performed to evaluate co-occurring semiological features in the two groups.

RESULTS

Compared to patients with ETS, those with NTEs more frequently had predominant involvement of proximal upper extremities (UE) (67% vs. 21%), internal rotation of UE (67% vs. 3%), adduction of UE (80% vs. 6%) and bilateral elbow extension (80% vs. 6%). In contrast, those with ETS more frequently had abduction of UE (82% vs 0%), elevation of UE (91% vs. 33%), open eyelids (74% vs. 20%), and involvement of both proximal and distal UE (79% vs. 27%). In addition, seizures that remained symmetrical throughout were more likely to have a generalized onset than focal (38% vs. 6%), p = 0.032, PPV 86%.

CONCLUSIONS

A careful analysis of semiology can often help differentiate between ETS and NTE in the ICU. The combination of eyelids open, upper extremity abduction, and elevation reached a PPV of 100% for ETS. The combination of bilateral arms extension, internal rotation, and adduction reached a PPV of 90.9% for NTE.

Tumor-related epilepsy: epidemiology, pathogenesis and management

INTRODUCTION

Seizure is a common comorbidity in patients with brain tumor. It may be the presenting symptom or develop after the tumor diagnosis. The underlying pathophysiology of brain tumor-related epilepsy remains poorly understood.

METHODS

A comprehensive literature review of Pubmed English articles from 1980-2017 was performed to summarize current knowledge and treatment options of brain tumor-related epilepsy.

RESULTS

Multiple factors have been found to contribute to tumor-related epilepsy, including tumor type, speed of tumor growth, location, and tumor burden. The underlying pathogenesis of epilepsy is not clear but perturbations in the peri-tumoral regions, both structural and cellular communications, have been implicated.

CONCLUSIONS

Surgical and medical treatments of tumor-related epilepsy remain challenging as additional factors such as the extent of surgical resection, interactions with tumor-related oncological treatments and anti-epileptic medication related side effects need to be considered.

Seizures and Choice of Antiepileptic Drugs Following Subarachnoid Hemorrhage: A Review

Seizures are important complications following a subarachnoid hemorrhage (SAH). The evidence for the use of antiepileptic drugs (AEDs) in treatment and prevention of those seizures is conflicting. The purpose of this review is to provide an up-to-date evidence summary of the incidence and outcomes of seizures following an SAH as well as the use of different AEDs post-SAH in order to evaluate the need for seizure prophylaxis, the choice of AEDs, and their dosing considerations in SAH patients. A literature search of PubMed, Medline, Embase, and the Cochrane Library was performed. A total of 37 studies were reviewed, mostly observational. Definitions of seizures in temporal relation to initial hemorrhage were variable. Similarly, the rates of seizures varied in the literature, ranging from 0 to 31%. Given the reported adverse outcomes associated with AED usage, seizure prophylaxis is not warranted. Levetiracetam appears to be better tolerated than phenytoin in SAH patients, though further research is needed. Higher initial dosing of levetiracetam might be required due to its enhanced clearance in SAH patients. In conclusion, there is a lack of quality evidence to definitively recommend the use of one AED over another. Further prospective research comparing the use of different AEDs in patients with an SAH is needed.

Seizures and the neurosurgical intensive care unit

The cause of seizures in the neurosurgical intensive care unit (NICU) can be categorized as emanating from either a primary brain pathology or from physiologic derangements of critical care illness. Patients are typically treated with parenteral antiepileptic drugs. For early onset ICU seizures that are easily controlled, data support limited treatment. Late seizures have a more ominous risk for subsequent epilepsy and should be treated for extended periods of time or indefinitely. This review ends by examining the treatment algorithms for simple seizures and status epilepticus and the role newer antiepileptic use can play in the NICU.

Treatment of seizures in the neurologic intensive care unit

Seizures occur more often in the neurologic intensive care unit (NICU) than in general or other specialty ICUs, in part because of the patient population, but also due to the enhanced neurologic monitoring undertaken in such units. Especially important for the detection of seizures is the use of specialty trained personnel and the use of continuous electroencephalographic monitoring. The etiology of seizures often can be categorized either by primary brain pathology, at macro- or microscopic level, or by physiologic derangements of critical care illness, such as toxic or metabolic abnormalities. Particular etiologies at risk for seizures include hemorrhagic stroke and traumatic brain injury. The use of prophylactic antiepileptic drug administration remains controversial. If seizures occur, patients are typically treated with parenteral antiepileptic drugs. The duration of treatment is unclear in most situations, but data support limited treatment for early-onset ICU seizures that are easily controlled, with treatment not extending beyond a few weeks or a month. Late seizures, which occur more than 2 weeks after the insult, have a more ominous correlative risk for subsequent epilepsy and should be treated for extended periods of time or indefinitely. Electrolyte and glucose abnormalities, when corrected, usually lead to seizure control. This review concludes by examining the treatment algorithms for simple seizures and status epilepticus and the role newer antiepileptic use can play in the NICU.

Seizures and status epilepticus in the critically ill

Seizures represent stereotypic electroencephalographic (EEG) and behavioral paroxysms as a consequence of electrical neurologic derangement. Seizures are usually described as focal or generalized motor convulsions; however, nonconvulsive seizures that occur in the absence of motor activity may escape clinical detection. Because of the admission diagnoses and dramatic physiologic and metabolic derangements common to critically ill patients, the entire spectrum of seizure disorders may be encountered in the ICU. Seizures in the ICU are attributable to primary neurologic pathology or secondary to critical illness and clinical management. For optimal treatment, early diagnosis of the seizure type and its cause is important to ensure appropriate therapy. Convulsive status epilepticus requires emergent treatment before irreversible brain injury and severe metabolic disturbances occur.

Management of Seizures in the Critically Ill

Seizures in a critically ill patient are not infrequent phenomena. Physicians are perplexed by the wide range of possible cranial or extracranial etiologies, alerted by the risk for further crucial organ compromise if seizures recur, and confused about the treatment options in an environment rich in complex drug interactions and multiple organ dysfunction. The advent of an armamentarium containing multiple new antiepileptic medications complicates the situation further, since several of them have less known mechanisms of action, side effects, or interactions with other intensive care unit (ICU) medications. This review contains useful information regarding the most common etiologies and treatment options for intensivists, consulting neurologists, neurosurgeons, or other specialized physicians treating ICU patients with seizures.

Refractory status epilepticus in adults

The management of status epilepticus has improved over the past 20 years, resulting in a substantial decrease in the associated morbidity and mortality. Patients who have seizures that are refractory to initial pharmacologic interventions tend to have significant underlying toxic, metabolic, structural, or infectious disorders, and therefore management of refractory status epilepticus must focus on stabilization and on identification and correction of seizure etiology. Regardless of etiology, the faster the seizures are brought under control, the better the prognosis. Risk of central nervous system injury increases after 30 minutes of seizure activity, and therefore efforts should focus on controlling the abnormal electrical discharges at the earliest time possible, preferably within one hour. Benzodiazepines, phenytoin, and phenobarbital remain the most commonly used first- and second-line anticonvulsants, have proven effective in cases of status epilepticus, and should be administered within the first 45 minutes of management. For refractory status epilepticus, pentobarbital anesthesia is evolving as an effective and recommended treatment modality and should be instituted immediately after phenytoin and phenobarbital loading. The role of other anticonvulsants remains to be investigated in controlled clinical trials.