Benign Epilepsy with Centrotemporal Spikes Case File

Benign Epilepsy with Centrotemporal Spikes Case File

Eugene C. Toy, MD, Ericka Simpson, MD, Pedro Mancias, MD, Erin E. Furr-Stimming, MD

CASE 49

A right hand–dominant 7-year-old boy is brought to the emergency room (ER) after having had an unusual spell at night. He came into his parent’s room looking very frightened, making gurgling noises but unable to speak, with twitching noted over the right side of his face. After approximately 30 seconds, he fell to the ground and had a 2-minute generalized tonic-clonic event. Immediately afterward he was drowsy and confused but now is completely back to his normal baseline. His vital signs are within the range of normal for his age, and his physical examination, including a detailed neurologic examination, is normal. He has never experienced any similar events, and there is no history of febrile seizures, central nervous system (CNS) infections, significant head trauma, headaches, developmental or behavioral problems, or changes in personality. He was born at 38 weeks of gestation after an uneventful pregnancy and went home on the second day of life. He has not been febrile nor had any recent illnesses. The child’s father states that he had similar episodes as a child.

▶ What is the most likely diagnosis?

▶ What is the next diagnostic step?

▶ What is the next step in therapy?

ANSWERS TO CASE 49:

Benign Epilepsy with Centrotemporal Spikes                                         

Summary: This is a 7-year-old boy, full term, with no significant past medical history and normal development who is brought to the ER after a nocturnal spell involving speech arrest and hemifacial spasms, followed by an apparent secondarily generalized tonic-clonic seizure. He had brief postictal confusion, and quickly returned to his normal baseline. His examination is unremarkable. The family history is significant for similar episodes in his father when he was a child.

• Most likely diagnosis: Benign epilepsy with centrotemporal spikes (BECTS).
• Next diagnostic step: Perform an electroencephalograph (EEG) as an outpatient.
• Next step in therapy: Reassurance as well as monitoring for subsequent events.

ANALYSIS

Objectives

1. Understand the difference between partial, generalized, and secondarily generalized seizures.
2. Know the clinical characteristics of BECTS.
3. Be aware of long-term prognosis of BECTS and considerations in deciding on treatment.
4. Know when a focal seizure in childhood requires further workup and how to proceed with such an evaluation.

Considerations

This 7-year-old boy experienced a nocturnal seizure with secondary generalization and was not associated with any obvious provocation. The most likely diagnosis is BECTS, also known as benign rolandic epilepsy (BRE). BECTS accounts for 6% to 10% of all childhood epilepsies, making it the most common focal epilepsy of childhood. Typically, it has its onset between 3 and 10 years with a peak onset of 7 to 8 years, resolving by age 18. BECTS has no known etiology, but because of positive family history in about one-fourth of patients, there is a presumed genetic basis that still remains to be unclear. This type of epilepsy is more common in boys. About two-thirds of patients will have only one or very few seizures. The typical seizure presentation with BECTS includes clonic or tonic activity of one side of the lower face; paresthesia of the tongue, lips, gum, and cheek; and drooling and arrest of speech or dysarthria. Hemiconvulsions are more common in young children, and evolution to bilateral convulsive activity is more frequent in sleep. Most of the seizure activity is at night, related to falling asleep or awakening from sleep. The EEG is particularly helpful in making the diagnosis of BECTS; as the name implies, patients will have epileptiform discharges in the central and temporal regions. The seizure description, the age of the patient, the onset during sleep, and the family history of similar episodes in his father are together highly suggestive of BECTS (see also Case 44).

APPROACH TO:

Benign Epilepsy with Centrotemporal Spikes                                              

TERMINOLOGY

Understanding of the terminology used to describe seizures is essential to the discussion of any specific type of epilepsy. According to the 2010 International League Against Epilepsy (ILAE) classification, the term generalized is used if the seizure onset involves both cerebral hemispheres. The term focal, also referred to previously as partial or as localization-related, is used if the seizures begins in one part of one hemisphere.

Focal seizures can be further categorized into those that do not impair consciousness—simple focal seizures—and those that do impair consciousness, complex partial seizures. It is not uncommon for focal seizures to spread and involve a greater cortical region as the seizure progresses. If this abnormal activity spreads to the contralateral hemisphere, the seizure is said to be secondarily generalized. This would appear to be what happened in the case under consideration because the child initially had focal manifestations (speech arrest and right hemifacial spasm), followed by generalized motor activity (a generalized tonic-clonic seizure).

A focal seizure is by definition a manifestation of a focal physiologic abnormality in the cortex. Sometimes this will be associated with an anatomic abnormality seen with a magnetic resonance imaging (MRI) scan, and sometimes the MRI will not show the lesion. Examples of common causes of such a lesion would be trauma, stroke, infection, tumor, or a congenital malformation of cortical development. If an anatomic substrate is seen in association with the region of seizure onset (the seizure focus), the disorder is classified as structural. If the patient has a metabolic condition that predisposes them to have seizures, the disorder is classified as metabolic. Alternatively, a seizure focus can exist without any obvious finding on neuroimaging. In this case, the disorder would be considered unknown (previously referred to as cryptogenic, indicating that the cause remains hidden). The final category of epilepsies is genetic, which refers to conditions in which there is a known or presumed genetic etiology. The most common focal epilepsy of childhood, BECTS, is an example of a (presumed) genetic epilepsy which is highly heritable, although the mode of that inheritance remains unclear.

CLINICAL PRESENTATION

The clinical manifestations, or semiology, of focal seizures reflect the normal function of the region of the brain from which they arise. For example, an occipital lobe focus can produce visual manifestations, whereas a focus in the primary motor cortex can generate contralateral tonic and/or clonic activity. In this patient, speech arrest and right hemifacial spasm suggest a seizure focus near the facial aspect of the left motor strip as well as the nearby regions responsible for expressive language. This would be consistent with a perirolandic location involving the lateral aspect of the left hemisphere near the central sulcus (formerly referred to as the rolandic fissure). Information about seizure presentation is combined with the findings of MRI and electroencephalography (EEG) in an attempt to localize the focal abnormality.

BECTS is labeled benign because this type of epilepsy is not typically associated with any neurocognitive or behavioral abnormalities. It resolves before reaching adulthood, in most patients it is associated with infrequent seizures, and it is typically easily treated or so mild that treatment is not necessary. Frequent seizures are seen in only 6% of the cases, while 13% to 21% will have only one single event. The number of seizures the patient experiences will play an important factor when considering whether to begin anticonvulsant therapy.

Obtaining an EEG is particularly helpful in making the diagnosis of BECTS because characteristic features can be seen interictally. Typically, the interictal EEG will show centrotemporal (perirolandic) spikes, which may be bilateral or unilateral. If a period of sleep is captured during the recording session, approximately 30% of patients with BECTS will have sharp waves seen arising from the centrotemporal region. If both the history and the EEG are consistent with BECTS, and there is a normal neurologic examination without significant neurocognitive or behavioral changes, no further diagnostic workup needs to be undertaken. If the history is consistent but the EEG is unrevealing, then it can be worth obtaining a prolonged EEG to see if diagnostic abnormal activity can be captured. Certainly, if there are focal features on neurologic examination, concerning aspects to the history (such as developmental regression), or abnormalities on EEG that are inconsistent with BECTS, then neuroimaging with an MRI should be strongly considered.

TREATMENT

Once the diagnosis is made, consideration must turn to treatment. Most patients experience only one or very few seizures, and all patients eventually outgrow BECTS. Also, although this is a matter of some debate, there is no evidence whether treatment should be started right away. Some studies recommend withholding treatment unless there were multiple seizures, cognitive changes, quality-of-life changes, and generalized tonic-clonic seizures. Clearly this is a decision that must be tailored to the individual patient in careful consultation with the child and the child’s parents.

PROGNOSIS

Remission occurs in essentially all children: 50% by age 6, 92% by age 12, and 99.8% by age 18. The diagnosis of BECTS must be reconsidered in patients who do not respond to treatment, whose seizures persist into adulthood, or who have very frequent or otherwise atypical seizures or neurocognitive/behavioral deficits which persist or are severe.

CASE CORRELATION

• See also Case 44 (New-Onset Seizure, Child)

COMPREHENSION QUESTIONS

49.1 A third-year medical student observes a seizure occurring in one of the neurology intensive care unit (ICU) patients which involved isolated twitching of one hand and no impairment of consciousness. The patient’s computed tomography (CT) of the brain showed a stroke in the hemisphere contralateral to the hand twitching. Which of the following is the most appropriate description?

A. Generalized seizure

B. Focal, genetic seizure

C. Focal, structural seizure

D. Focal, metabolic seizure

E. Focal seizure with secondary generalization

49.2 Which of the following is typical of seizures seen in patients with BECTS?

A. Seizures occur mostly during the daytime.

B. Seizures are generalized from the outset.

C. Seizures primarily involve the lower extremities.

D. Seizures recur frequently.

E. Seizures often begin in the face or mouth.

49.3 A 9-year-old girl is brought to the clinic with a history entirely consistent with the diagnosis of BECTS. An EEG is obtained that reveals the centrotemporal sharp waves characteristic of this disorder. The patient has had one witnessed seizure 2 weeks ago and had one unwitnessed event 1 year ago, which may have been a seizure. The child’s parents are not very interested in beginning daily anticonvulsant medication. Which of the following would be the best course of treatment for this patient?

A. Strongly encourage the parents to begin a low dose of daily valproic acid.

B. Prescribe prophylactic diazepam in case of febrile illness.

C. Reassure the family and encourage “watchful waiting” to see if further seizures occur.

D. Obtain an MRI prior to making any treatment recommendations.

E. Recommend twice-daily dosing of oxcarbazepine.

ANSWERS

49.1 C. Because the patient had motor activity only in one hand, this would be focal. A focal seizure with a stroke in the region of the brain related to the observed clinical event would be considered to have a structural etiology.

49.2 E. The seizures of BECTS are usually nocturnal, infrequent, begin with orofacial involvement, and can secondarily generalize.

49.3 C. In the context of typical BECTS with infrequent seizures, “watchful waiting” is the most prudent approach. An MRI is unnecessary in this patient at this time.

    CLINICAL PEARLS    

▶ Although BECTS is the most common focal epilepsy of childhood, the most common focal epilepsy in adults is temporal lobe epilepsy. ▶ A small subset of patients has been described with malignant rolandic epilepsy, in which the seizures look similar to those of BECTS but are frequent, difficult to treat, and do not remit by 16 years. It is likely that these patients have a different syndrome rather than a severe form of BECTS. ▶ Approximately 50% of patients with BRE are not treated with anticonvulsants because the seizures are infrequent.

REFERENCES

Berg AT, Berkovic SF, Brodie MJ, et al. Revised terminology and concepts for organization of seizures and epilepsies: report of the ILAE Commission on Classification and Terminology, 2005–2009. Epilepsia. 2010;51(4):676-685. 

Camfield P, Camfield C. Epileptic syndromes in childhood: clinical features, outcomes, and treatment. Epilepsia. 2002;43(suppl 3):27-32. 

Camfield P, Camfield C. Rolandic epilepsy has little effect on adult life 30 years later. Neurology. 2014;82:1162-1166. 

Guerrini R, Pellacani S. Benign childhood focal epilepsies. Epilepsia. 2012;53(suppl 4):9-18. 

Hughes JR. Benign epilepsy of childhood with centrotemporal spikes (BECTS): to treat or not to treat, that is the question. Epilepsy Behav. 2010;19:197-203. 

Loiseau P. Idiopathic and benign partial epilepsies. In: Wyllie E, ed. The treatment of epilepsy: principles and practice. Philadelphia, PA: Lippincott Williams and Wilkins; 2001:475-484. 

Panayiotopoulos CP. Atlas of Epilepsies. London, UK: Springer Science & Business Media; 2010. 

Willer E. Infantile, childhood, and adolescent epilepsies. Continuum (Minneap Minn). 2016;22:60-93. 

Willmore LJ. Treatment of benign epilepsy syndromes throughout life. Epilepsia. 2001;42(suppl 8):6-9.

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