Chapter 16
Acute Symptomatic Seizures
CQ 16-1

What is the definition of acute symptomatic seizure?
Summary
Acute symptomatic seizures are seizures that occur in close temporal association with acute central nervous systemdisorders, which include metabolic, toxic, structural, infectious, or inflammatory disorders.

CommentThe Commission on Epidemiology and Prognosis of the ILAE defined acute symptomatic seizures as “seizures occurringin close temporal association with an acute systemic, metabolic, or toxic encephalopathy or in association with an acutecentral nervous system disorder (infection, stroke, head injury, or acute alcohol intoxication or withdrawal)”1). This definition
was also adopted by Beghi et al.2).
Among acute symptomatic seizures, convulsive seizures mostly occur only once, but may be repeated or even develop tostatus epilepticus. Convulsive seizures may recur when the above disorders relapse.
Acute symptomatic seizure is clearly distinguished from epileptic seizure unprovoked by organic disorders (see CQ 1-1 onpage 2).

▪ References1) Guidelines for epidemiologic studies on epilepsy. Commission on Epidemiology and Prognosis, International League Against Epilepsy. Epilepsia.
1993; 34(4): 592-596.
2) Beghi E, Carpio A, Forsgren L, et al. Recommendation for a definition of acute symptomatic seizure. Epilepsia. 2010; 51(4): 671-675.

▪ Search formula and secondary reference sources
PubMed search: November 28, 2008
Acute symptomatic seizure = 222
Additional PubMed search: May 7, 2015
Acute symptomatic seizure (Filters: Clinical Trial; Multicenter Study; Randomized Controlled Trial; Systematic Reviews; Meta-Analysis;)= 28
No references that could serve as evidence were found in Ichushi Web.

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CQ 16-2

What are the causes of acute symptomatic seizures?
Summary
The etiologies of acute symptomatic seizures include cerebrovascular disease, central nervous system infection,acute immune-mediated encephalopathies, head injury, metabolic or systemic disease, intoxication, withdrawal,
post-neurosurgical operation, demyelinating disease, post-radiation therapy, and overlap of several etiologies.

Comment
The major etiologies for acute symptomatic seizures are shown in Table 11-4).
Acute symptomatic seizures differ from epilepsy in having clearly identifiable etiologies, having high mortality rates dueto the acute diseases, and requiring short-term treatment with antiepileptic drugs4, 5). Acute symptomatic seizures often occur
in the neonates and the elderly, similarly to epilepsy.

▪ References
1) Annegers JF, Hauser WA, Lee JR, et al. Incidence of acute symptomatic seizures in Rochester, Minnesota, 1935-1984. Epilepsia. 1995; 36(4): 327-333.
2) Huang CC, Chang YC, Wang ST. Acute symptomatic seizure disorders in young children—a population study in southern Taiwan. Epilepsia. 1998;
39(9): 960-964.
3) Murthy JM, Yangala R. Acute symptomatic seizures-incidence and etiological spectrum: a hospital-based study from South India. Seizure. 1999;
8(3): 162-165.
4) Leung H, Man CB, Hui AC, et al. Prognosticating acute symptomatic seizures using two different seizure outcomes. Epilepsia. 2010; 51(8): 1570-1579.
5) Beghi E, Carpio A, Forsgren L, et al. Recommendation for a definition of acute symptomatic seizure. Epilepsia. 2010; 51(4): 671-675.

▪ Search formula and secondary reference sources
PubMed search: November 28, 2008
Acute symptomatic seizure = 222
Additional PubMed search: May 7, 2015
Acute symptomatic seizure (Filters: Clinical Trial; Multicenter Study; Randomized Controlled Trial; Systematic Reviews; Meta-Analysis;)= 28
No references that could serve as evidence were found in Ichushi Web.

Table 1. Major acute symptomatic seizures.
Cerebrovascular disease
CNS infection
Immune-mediatedencephalopathies
Head injury
Metabolic or systemic disorders

Intoxication

Withdrawal
Post-neurosurgical operation
Demyelinating disease
Post-radiotherapy
Multiple etiologies

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Seizure occurring within 7 days of cerebrovascular attack
Seizure occurring in the acute phase of CNS infection
See CQ16-6 (page 161)
Seizure occurring within 7 days of head trauma
Seizure occurring in association with systemic diseases including electrolyte imbalance,
hypoglycemia, non-ketotic hyperglycemia, uremia, hypoxic encephalopathy, hepaticencephalopathy, hypertensive encephalopathy, eclampsia, posterior reversible encephalopathy
syndrome (PRES), systemic lupus erythematosus (SLE), and mitochondrial encephalopathy
Seizure occurring when taking narcotics (such as cocaine), prescribed drugs (such asaminophylline and imipramine), dangerous drugs, drug overdose, environmental pollution(such as carbon monoxide, lead, camphor, and organophosphorus), and alcohol (such as acutealcohol intoxication).
Seizure occurring within 1‒3 days after discontinuation of alcohol and drugs (such as barbiturate
and benzodiazepines) in patients who are addicted to those agents
Seizure occurring immediately after intracranial surgery
Seizure occurring in the acute phase of acute disseminated encephalomyelitis or multiple sclerosis
Seizures occurring within 24 hours after radiation exposure
Seizure related to several concomitant conditions

The Clinical Practice Guidelines for Epilepsy 2018

CQ 16-3

How to manage patients with acute symptomatic seizures?
SummaryIn patients with acute symptomatic seizures, we promptly measure vital signs including consciousness level, takehistory, perform general and neurological examinations, and continue to perform these procedures.

CommentFigures 1 and 2 show the flow chart of clinical investigation of patients suspected of acute symptomatic seizures.
In patients with convulsion, we first perform procedures to prevent injury or aspiration. Check vital signs and consciousness
level, and perform respiratory and circulatory management if needed. Suspect inflammatory disease if the patient has afever; and consider hypertensive encephalopathy, posterior reversible encephalopathy syndrome (PRES), or eclampsia if thepatient has severe hypertension. In the case of status epilepticus, start treatment for status epilepticus (see Chapter 8).
For history taking, we should obtain information about symptoms at seizure attack, history of trauma, diseases undertreatment (for example, hypoglycemia if receiving insulin injection for diabetes), current medications (for example, drugintoxication if taking massive dose of drug), alcohol drinking history (alcohol dependence, acute alcohol intoxication orwithdrawal), and possibility of pregnancy.
For general physical examination, check for injury, incontinence, bite wound, skin conditions (color, rash, cyanosis, etc.),
breath odor, and tachypnea. If arrhythmia, cardiac murmur, or cyanosis is present, consider the possibility of syncope,
cerebral embolism or heart failure1).
For neurological examinations, first check the level of consciousness, then suspect meningitis or encephalitis if meningeal
irritation signs are present, brain tumor or cerebrovascular disease if focal neurological signs are present, and hypocalcemia
if Trousseau signs or Chvostek signs are present.

▪ References
1) National Collaborating Centre for Primary Care. The diagnosis and management of the epilepsies in adults and children in primary and secondarycare. 2004.

▪ Search formula and secondary reference sources
PubMed search: November 28, 2008
Acute symptomatic seizure = 222
Additional PubMed search: May 7, 2015
Acute symptomatic seizure (Filters: Clinical Trial; Multicenter Study; Randomized Controlled Trial; Systematic Reviews; Meta-Analysis;)= 28
No references that could serve as evidence were found in Ichushi Web.

Chapter 16133

Figure 1. Procedures of investigation for patients suspected of acute symptomatic seizures, and examples.
Convulsive seizure, seizure with lossof consciousness
Vital sign (conscious state)evaluation

Respiratory and circulatory management as necessary, treatment for status epilepticus

Medical history

Situation of seizure, past history including trauma, diseases being treated, drugs being
used, drinking history, pregnancy, etc.

General physical examination

Injury, incontinence, bite, skin color, breath odor, tachypnea, etc.
Arrythmia, heart murmur, cyanosis

Neurological examinations

Level of impaired consciousness, meningeal irritation sign, focal neurological signs,
Trousseau signs, Chvostek signs

Other examinations

Blood tests, head CT or MRI, EEG, ECG, chest X ray, etc.
If necessary, cerebrospinal fluid examination

Treatment

Treatment of underlying disease
Antiepileptic drugs in case of high probability of relapse

Figure 2. Flowchart for diagnosis of acute symptomatic seizures.

Situation-related seizure: seizure induced only in the presence of inducing factor.
Isolated seizure: unprovoked seizure occurring once in the lifetime.
Broken line in figure suggests the possibility of transition in some cases.
Note: “Epileptiform” in the figure signifies symptoms caused by a state of excessive activationin the brain, and does not necessarily mean seizure symptoms of epilepsy as a chronic disease.
(Modified from: Ikeda A, Shibazaki H. Convulsion; differentiation between syncope andepilepsy. In: Sugimoto T, Omata M (ed.) Differential Diagnosis in Internal Medicine, 2ndedition. Tokyo: Asakura Publishing Co. Ltd. 2003. p.87‒96)

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Part IThe Clinical Practice Guidelines for Epilepsy 2018

CQ 16-4

What kinds of examination are needed for acute symptomaticseizures?
Summary
Conduct blood test, brain CT or MRI, EEG, electrocardiogram, and chest X-ray, and perform cerebrospinal fluid
examination if necessary.

CommentCheck for hypoglycemia, hypocalcemia, hyponatremia, high creatinine (uremic encephalopathy), high ammonia (hepaticencephalopathy), antinuclear antibody [systemic lupus erythematosus (SLE) and vasculitis], and antibodies of immunemediated encephalopaties1). Brain CT or MRI is critical for the diagnosis of brain tumor, brain abscess, brain granuloma,
and cerebrovascular disease2, 3). Perform cerebrospinal fluid examination if meningitis or encephalitis is suspected in febrilepatients with headache or impaired consciousness.

▪ References
1) National Collaborating Centre for Primary Care. The diagnosis and management of the epilepsies in adults and children in primary and secondarycare. 2004.
2) Harden CL, Huff JS, Schwartz TH, et al. Reassessment: neuroimaging in the emergency patient presenting with seizure (an evidence-based review):
report of the Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology. Neurology. 2007; 69(18): 1772-1780.
3) Krumholz A, Wiebe S, Gronseth G, et al. Practice parameter: evaluating an apparent unprovoked first seizure in adults (an evidence-based review):
report of the Quality Standards Subcommittee of the American Academy of Neurology and the American Epilepsy Society. Neurology. 2007;
69(21): 1966-2007.

▪ Search formula and secondary reference sources
PubMed search: November 28, 2008Acute symptomatic seizure = 222
Additional PubMed search: May 7, 2015
Acute symptomatic seizure (Filters: Clinical Trial; Multicenter Study; Randomized Controlled Trial; Systematic Reviews; Meta-Analysis;)= 28
No references that could serve as evidence were found in Ichushi Web.

Chapter 16

135

CQ 16-5

How to treat acute symptomatic seizures?
Summary
For acute symptomatic seizures, treat the underlying disease and start antiepileptic drugs if there is a highprobability of seizure recurrence.

CommentIf seizure persists, treat as for status epilepticus (see Chapter 8). In the case of a highly probable seizure recurrence in theacute phase, intravenous injection of fosphenytoin, phenytoin, levetiracetam or phenobarbital is useful for patients who havedifficulties in taking oral antiepileptic drugs1, 2). Conventional oral antiepileptic drugs are useful for patients capable of oral
intake3-5).
Avoid chronic prophylactic use of antiepileptic drugs and stop their administration after a short period, because continuous
administration does not prevent transition to epilepsy2).

▪ References1) Minicucci F, Muscas G, Perucca E, et al. Treatment of status epilepticus in adults: guidelines of the Italian League against Epilepsy. Epilepsia. 2006;
47(Suppl 5): 9-15.
2) Koppel BS. Treatment of acute and remote symptomatic seizures. Curr Treat Options Neurol. 2009; 11(4): 231-241.
3) Temkin NR. Antiepileptogenesis and seizure prevention trials with antiepileptic drugs: meta-analysis of controlled trials. Epilepsia. 2001; 42(4):515-524.
4) Marson AG, Williamson PR, Clough H, et al. Carbamazepine versus valproate monotherapy for epilepsy: a meta-analysis. Epilepsia. 2002; 43(5):505-513.
5) Glauser T, Ben-Menachem E, Bourgeois B, et al. ILAE treatment guidelines: evidence-based analysis of antiepileptic drug efficacy and effectivenessas initial monotherapy for epileptic seizures and syndromes. Epilepsia. 2006; 47(7): 1094-1120.

▪ Search formula and secondary reference sources
PubMed search: November 28, 2008
Acute symptomatic seizure = 222
Additional PubMed search: May 7, 2015
Acute symptomatic seizure (Filters: Clinical Trial; Multicenter Study; Randomized Controlled Trial; Systematic Reviews; Meta-Analysis;)= 28
No references that could serve as evidence were found in Ichushi Web.

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Part IThe Clinical Practice Guidelines for Epilepsy 2018

CQ 16-6

How to diagnose and treat anti-NMDA receptor encephalitis?
Summary(1) If acute symptomatic seizures are suspected to be caused by anti-NMDA receptor encephalitis, perform brain
MRI and cerebrospinal fluid examination and consider to measure anti-NMDA receptor antibody. Perform asystemic search for the presence of neoplastic disorders including ovarian teratoma.
(2) A fter starting appropriate circulatory and respiratory management, consider surgical resection of the tumor
in the early stage if paraneoplastic syndrome is suspected. Also consider steroid pulse therapy, high-dose
intravenous immunoglobulin therapy, plasmapheresis, and immunosuppressants (currently not covered by
medical insurance).

Comment
Anti-N-methyl-D-aspartate (NMDA) receptor encephalitis is more prevalent in young women. It initially manifests
diverse psychiatric symptoms such as emotional disorder, memory impairment, hallucination, and delusion; and later shows
convulsive seizures and involuntary movements such as dyskinesia, respiratory failure, and autonomic nervous systemsymptoms1, 2). Convulsive seizures may be the initial symptom3).
Brain MRI shows high signal intensity regions in mesial temporal lobe, cerebral cortex, and cerebellum on T2-weighted
images. Cells and proteins increase in cerebrospinal fluid. However, these abnormal findings are absent in some cases1, 2).
Measurement of autoantibodies including anti-NMDA receptor antibody in blood and cerebrospinal fluid specimens isrequisite for the diagnosis1, 2). However, these tests can be done only in a limited number of facilities. Systemic search formalignancies is recommended because tumors such as ovarian teratoma may be involved in the pathophysiology1, 2, 4).
We should consider early surgical resection of a tumor when its involvement is suspected1, 2). When acute anti-NMDA
receptor antibody encephalitis is strongly suspected, consider steroid pulse therapy, high-dose immunoglobulin therapy,
plasmapheresis, and immunosuppressants1, 3, 4). There is no high level evidence for the choice of treatment method.

▪ References1) Dalmau J, Gleichman AJ, Hughes EG, et al. Anti-NMDA-receptor encephalitis: case series and analysis of the effects of antibodies. Lancet Neurol.
2008; 7(12): 1091-1098.
2) Titulaer MJ, McCracken L, Gabilondo I, et al. Treatment and prognostic factors for long-term outcome in patients with anti-NMDA receptor
encephalitis: an observational cohort study. Lancet Neurol. 2013; 12(2): 157-165.
3) Viaccoz A, Desestret V, Ducray F, et al. Clinical specificities of adult male patients with NMDA receptor antibodies encephalitis. Neurology. 2014;82(7): 556-63.
4) Iizuka T, Sakai F, Ide T, et al. Anti-NMDA receptor encephalitis in Japan: long-term outcome without tumor removal. Neurology. 2008; 70(7):504-511.

▪ Search formula and secondary reference sources
PubMed search: December 11, 2014
“anti-n-methyl-d-aspartate receptor encephalitis” [MeSH Terms] OR (“anti-n-methyl-d-aspartate” [All Fields] AND “receptor” [All Fields] AND“encephalitis” [All Fields]) OR “anti-n-methyl-d-aspartate receptor encephalitis” [All Fields] OR (“anti” [All Fields] AND “nmdar” [All Fields]AND “encephalitis” [All Fields]) OR “anti nmdar encephalitis” [All Fields] = 399 Among the 399 papers, the above references were reviewed.
No references that could serve as evidence were found in Ichushi Web.

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