Status Epilepticus: Classification, Clinical Features, and Diagnosis

Primary Category

Neurocritical Care

P-Category

Secondary Category

Epilepsy

S-Category

Authors:

Rizwan Raheem MD,
Filzah Faheem MD,
Junaid Kalia MD

Introduction

A medical and neurological emergency condition

✨

The International League Against Epilepsy (ILAE) defines as

A single epileptic seizure for >30 min duration

A series of epileptic seizures without regaining function for> >30 min period

Operational definition in adults and children >5 years old

≥5 minutes of continuous seizures, or
≥2 discrete seizures between which there is incomplete recovery of consciousness

Operational dimensions

Time point t1

time during which the treatment should be started

Time point t2

time during which long-term complications can occur.

Condition results from

failure of the seizure termination mechanisms
initiation of mechanisms leading to seizure (after time point t1)

Long-term consequences include

neuronal death
neuronal injury
neuronal networks alteration

Consequences depend upon

type of seizure
duration of seizures
occur after time point t2

Rapid management

reduces morbidity
Decreases mortality

Delayed management results in

poor prognosis
poor refractory seizure control

Epidemiology

Bimodal distribution

children <1 year
older adults >60 years

Generalized convulsive status epilepticus

Most frequent type
Fatal type of status epilepticus
Incidence rate: 7 out of100,000
20% death rate
Death rate is higher in the elder people about 30-70%

Etiology

Common cause of Status epilepticus in patients

With prior history of epilepsy

Withdrawal of anticonvulsant drugs
Non-adherence to anticonvulsant drugs

With or without prior history of epilepsy

Stroke
Hypoxia
Alcohol intoxication or withdrawal
Metabolic disturbances

Less common causes

Brain trauma
Brain tumor

Specific causes of Status Epilepticus

CNS Infections

Acute Encephalitis
Acute Meningitis
Cerebral abscess

Cerebrovascular causes

Stroke
Arteriovenous malformations
Subarachnoid haemorrhage

History of epilepsy

Non-adherence to anti-epileptic drugs
Discontinuation of anti-epileptic drugs

Metabolic causes

Hypoglycaemia
Hyperglycaemia
Hepatic encephalopathy
Hyponatremia
Hypocalcemia
hypomagnesemia
Uremia

Tumor

Brain tumors

Alcohol related/toxic causes

Heroine
Tetramine

Trauma

Head trauma

Hypoxic conditions

Cerebral anoxia
Cerebral hypoxia

Withdrawal syndromes

Alcohol withdrawal
Barbiturates withdrawal
Benzodiazepines withdrawal

Drug overdose

use of drugs that lower seizure threshold

lithium
Theophylline
Imipenem
Cefepime
Quinolone antibiotics
Tricyclic antidepressants
Bupropion

Classification

Classifying the type of status epilepticus is important in determining

Morbidity

Aggressiveness of treatment required

It is classified into Convulsive status epilepticus and non-convulsive status epilepticus

Table 1: ILAE Task Force Status Epilepticus Classification

Title

SEMIOLOGY AXES

ETIOLOGY AXES

EEG AXES

AGE AXES

1-With prominent motor symptoms (Convulsive status epilepticus) It is associated with or without loss of consciousness Accounts for 37-70 % of Status epilepticus patients a- Generalized Primary generalized convulsive Secondary generalized convulsive (focal evolve into bilateral generalized) Myoclonic Tonic Clonic Atonic b-Focal Jacksonian status epilepticus Epilepsia partialis continua- preserved awareness Oculoclonic seizures Ictal paresis 2-Without prominent motor symptoms It includes non-convulsive status epilepticus a-NCSE with coma - life threatening condition b- NCSE without coma i-Generalized non-convulsive status epilepticus Absence status epilepticus (Typical, atypical or myoclonic) ii-Focal non convulsive status epilepticus Associated with or without loss of consciousness Intact consciousness- auditory, sensory, gustatory, visual, autonomic or emotional symptoms. Aphasic status epilepticus

1-Known etiology Status epilepticus resulting from known conditions Acute: infections, alcohol or drug intoxication, electrolyte imbalance or stroke Remote: Post- traumatic status epilepticus or post-stroke patients Progressive: Structural lesions in the brain such a tumor, dementia Idiopathic and genetic are not included 2-Unknown etiology

Though evidence-based data is not available to classify. Following criteria can be used 1-Location Generalized pattern Localized pattern Multifocal pattern Bilateral/unilateral 2-Type of pattern Periodic Rhythmic delta wave Spike and wave discharges 3-Morphologic features Sharpness of waves Amplitude that can be absolute or relative Phases: triphasic or diphasic morphology Polarity 4-Time related Frequency Duration Onset Prevalence Dynamic: static, evolving, fluctuations 5-Modulation Stimulus induced epilepticus or spontaneous status epilepticus 6-Effect of medication, if given, on EEG

0-30 days: Neonates- Neonatal epilepsy syndromes 1month- 2 years: Infants- Infantile epilepsy syndromes 2-12 years: Childhood- Autonomic status epilepticus, NCSE in childhood syndromes 12-59: Adolescence and adulthood- Juvenile myoclonic or absence status epilepticus ≥59 Elder population-De novo status epilepticus or myoclonic in Alzheimer's

Clinical features

Variable presentation

Convulsive status epilepticus patients can present with

contraction of muscles/ jerky movements
stool or urinary incontinence
appearance of foam in the mouth
eye deviation
confusion
altered sensorium
memory changes
personality changes
Non convulsive status epilepticus patients can present with

Altered state of consciousness
Eye movements such as nystagmus, eye deviation etc.
Hiccups
Twitching of muscles of extremity or face
Absence of prominent motor symptoms
Urgent EEG should be done to exclude NCSE.

Clinical manifestations depending upon the type of seizure

Generalized convulsive status epilepticus

Altered consciousness
Bilateral tonic stiffness followed by clonic motor stiffness
Usually symmetric motor activity
Associated with very high morbidity and mortality

Focal motor status epilepticus

Motor activity limited to one region of the body
Can be easily seen
Motor activity can be focal or widespread
Consciousness may or may not be lost

Myoclonic status epilepticus

Usually generalized
Recurrent rhythmic or arrhythmic myoclonic motor activity
Mostly seen in children
Late onset myoclonic SE seen in

Down syndrome
Alzheimer disease

Diagnosis

Diagnosis is made clinically

Detailed neurological examination and baseline investigations required to rule out or to make alternate diagnosis

In order to diagnose non-convulsive status epilepticus, EEG serves as diagnostic tool.

Lab Investigations

FIRST LINE INVESTIGATIONS

Should be performed in every patient as this helps to decide the treatment strategy and to prevent complications

Full blood count

Abnormal FBC may be a sign of sepsis

Sodium, potassium, calcium and magnesium

Dyselectrolytemia can provoke seizures

Renal function tests

Impaired urea and creatinine can precipitate seizure

Liver function tests

Abnormal LFTs may be a sign of systemic disease or alcohol intoxication

Glucose

may be normal/hypoglycemic/hyperglycemic
Abnormal blood glucose level can precipitate/cause seizure

Infectious workup

Urine Analysis
X-ray Chest
Blood Culture

OPTIONAL INVESTIGATIONS

Decision should be made by physician according to the history of the patient

Coagulation screen

Helps to identify coagulopathy

Arterial blood gas (ABG)

Severe transient changes seen in patients with long standing seizures

Anticonvulsant drug levels

Subtherapeutic anti-epileptic drug level causes status epilepticus

Toxicology screen

Blood alcohol screening can be used to know recent alcohol levels in the blood
Urine toxicology screen helps to screen the level of illicit drugs in urine

Ammonia levels
Lactate level
Pregnancy test (in child bearing age)
Lumbar puncture

To rule out meningeal inflammation and infection (lymphocytic pleocytosis, increased protein)

Neurophysiological Studies

Electroencephalography (EEG)

Not needed in clinically evident status epilepticus

Helpful in diagnosing non-convulsive status epilepticus and excluding dissociative seizures

Helps to access effectiveness of treatment after confirmation of diagnosis

Continuous EEG should be performed for 24 hours to exclude non-convulsive seizures in patients who

do not show clinical improvement within 10 min
remain unconscious for > 30 min

Essential in differentiating myoclonic SE from nonepileptic myoclonic seizures

Myoclonic status epilepticus resulting from anoxia reveals

Disrupted flat background EEG changes
Associated with a poor outcome

EEG findings in non-convulsive status epilepticus

Periodic discharges for > 2.5/s (per ACNA 2021)
Repeated spike and waves for > 10s
Rhythmic delta activity

Neuroimaging

A STAT CT is recommended in ALL patients presenting with Status Epilepticus to rule out intracerebral hemorrhage

CT head other Indications

In patients with focal neurological deficits
No prior history of epilepsy
In a patient with refractory status epilepticus
To rule out any brain pathology

Peri-ictical MRI findings

Peri-ictal imaging changes occur in

region of the epileptic discharge (local) or

in distant structures (remote)

Local

Unilateral/bilateral diencephalic lesions
Pulvinar sign (Figure 1b)
Cerebellar diaschisis (Figure1c)
Splenium abnormalities
Posterior leukoencephalopathy
Hippocampal swelling

Remote

Mass effect
Sulcal effacement
Focal cortical lesions
Increased T2 signal
Diffusion changes (Figure 1a)
Blood brain barrier breakdown
Contrast enhancement
Increased vessel caliber/flow
Increased perfusion of inflammatory lesions

Knowledge of these findings is important because

Elucidate the pathophysiology of epileptic seizures

May be confused with focal pathology

brain tumor
stroke
encephalitis

May be helpful in surgical planning

Figure 1A: MR Finding of Status Epilepticus (DWI)

i) Seizure related restricted diffusion: shows seizure related right hippocampal and thalamus diffusion restriction

ii) Pulvinar sign: Bilateral restricted diffusion of both thalamus

Source: Di Muzio, B., Saber, M. Status epilepticus. Reference article, Radiopaedia.org. (accessed on 23 Sep 2021) https://radiopaedia.org/articles/33415

Figure 1B: MR Finding of Status Epilepticus (T2)

C) Crossed Cerebellar Diaschisis: Hypointensity in left corona radiata and insula along with right cerebellar hemisphera atrophy.

Source: Macagnan, M. Crossed cerebellar diaschisis. Case study, Radiopaedia.org. (accessed on 23 Sep 2021) https://radiopaedia.org/cases/47317

Differential diagnosis

Psychogenic status epilepticus

Delirium

Vasovagal syncope

Cardiac syncope

Coma

Management

Bibliography

Craig, D. P., Mitchell, T. N., & Thomas, R. H. (2020). A tiered strategy for investigating status epilepticus. Seizure, 75(April), 165–173. https://doi.org/10.1016/j.seizure.2019.10.004

Guidelines for epidemiologic studies on epilepsy. Commission on Epidemiology and Prognosis, International League Against Epilepsy. Epilepsia 1993; 34:592.

Trinka E, Cock H, Hesdorffer D, et al. A definition and classification of status epilepticus--Report of the ILAE Task Force on Classification of Status Epilepticus. Epilepsia 2015; 56:1515.

R.F.M. Chin, B.G.R. Neville, R.C. ScottA systematic review of the epidemiology of status epilepticus Eur J Neurol, 11 (December (12)) (2004), pp. 800-810

R.J. DeLorenzo, W.A. Hauser, A.R. Towne, J.G.Boggs, J.M. Pellock, L. Penberthy, et al.A prospective, population-based epidemiologic study of status epilepticus in Richmond, Virginia Neurology, 46 (April (4)) (1996), pp. 1029-1035

G. Logroscino, D.C. Hesdorffer, G. Cascino, J.F. Annegers, W.A. HauserShort-term mortality after a first episode of status epilepticus Epilepsia, 38 (December (12)) (1997), pp. 1344-1349

G. Logroscino, D.C. Hesdorffer, G. Cascino, W.A. Hauser, A. Coeytaux, B. Galobardes, et al.Mortality after a first episode of status epilepticus in the United States and Europe Epilepsia (2005), pp. 46-48

Sheth RD, Gidal BE. Intravenous valproic acid for myoclonic status epilepticus. Neurology. 2000 Mar 14;54(5):1201. doi: 10.1212/wnl.54.5.1201. PMID: 10720302.

Shaner, D M et al. “Treatment of status epilepticus: a prospective comparison of diazepam and phenytoin versus phenobarbital and optional phenytoin.” Neurology vol. 38,2 (1988): 202-7. doi:10.1212/wnl.38.2.202

Barry E, Hauser WA. Status epilepticus: the interaction of epilepsy and acute brain disease. Neurology 1993; 43:1473.

Bellante, Flavio et al. “Midazolam and thiopental for the treatment of refractory status epilepticus: a retrospective comparison of efficacy and safety.” Journal of neurology vol. 263,4 (2016): 799-806. doi:10.1007/s00415-016-8074-7

Ulvi H, Yoldas T, Müngen B, Yigiter R. Continuous infusion of midazolam in the treatment of refractory generalized convulsive status epilepticus. Neurol Sci. 2002 Oct;23(4):177-82. doi: 10.1007/s100720200058. PMID: 12536286.

Lv, R.-J., Wang, Q., Cui, T., Zhu, F., & Shao, X.-Q. (2017). Status epilepticus-related etiology, incidence and mortality: A meta-analysis. Epilepsy Research, 136, 12–17.doi:10.1016/j.eplepsyres.2017.07.006

Rossetti AO, Logroscino G, Bromfield EB. Refractory status epilepticus: effect of treatment aggressiveness on prognosis. Arch Neurol. 2005 Nov;62(11):1698-702. doi: 10.1001/archneur.62.11.1698. Erratum in: Arch Neurol. 2006 Oct;63(10):1482. PMID: 16286542.

Trinka E, Höfler J, Zerbs A. Causes of status epilepticus.Epilepsia. 2012 Sep;53 Suppl 4:127-38.

Walker M. Status epilepticus: an evidence based guide. BMJ. 2005 Sep 24;331(7518):673-7.

Von Oertzen J, Cock HR. Testing blood and CSF in people with epilepsy: a practical guide. Epileptic Disord. 2020; In press.

Egawa, S., Hifumi, T., Nakamoto, H., Kuroda, Y., & Kubota, Y. (2020). Diagnostic Reliability of Headset-Type Continuous Video EEG Monitoring for Detection of ICU Patterns and NCSE in Patients with Altered Mental Status with Unknown Etiology. Neurocritical Care, 32(1), 217–225. https://doi.org/10.1007/s12028-019-00863-9

Van Putten, M. J. A. M., & Hofmeijer, J. (2016). EEG monitoring in cerebral ischemia: Basic concepts and clinical applications. Journal of Clinical Neurophysiology, 33(3), 203–210.

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