PNES (previously termed pseudoseizures) may be the manifestation of conversion disorders or malingering. Additionally, children with genuine epilepsy may, consciously or subconsciously, exhibit concurrent nonepileptic spells. Although the clinical differentiation can be difficult, PNES often differ from epileptic seizures in that the patient’s eyes are often closed (typically eyes are open during epileptic seizures) and the movement is tremulousness or thrashing rather than true tonic-clonic activity. Verbalization and pelvic thrusting are seen more commonly in PNES, urinary and fecal continence is usually preserved, and injury does not occur. If the tongue is bitten, more often the tip of the tongue is injured (as opposed to the sides of the tongue in epileptic seizures). PNES can often be initiated or terminated by suggestion. An EEG performed during PNES does not show epileptiform patterns. The diagnosis is critical, because appropriate mental health care, and not anticonvulsant medications, is the crux of treatment.
The epilepsy syndromes represent clinical entities in which age,pattern of clinical events, EEG features, natural history, andprognosis are distinctive (see Table 181-3).
Benign childhood epilepsy with centrotemporal spikes, also known as benign Rolandic epilepsy, is among the most common epilepsy syndromes and usually begins between ages 5 and 10 years. The seizures typically occur only during sleep or on awakening in more than half of patients. Affected children usually have focal motor seizures involving the face and arm (abnormal movement or sensation around the face and mouth, drooling, rhythmic guttural sound). Speech and swallowing may be impaired. Seizures sometimes secondarily generalize. The interictal EEG demonstrates independent bilateral centrotemporal sharp waves but is otherwise normal. With a classic history and EEG, and a normal neurological examination, the diagnosis can be made with confidence and neuroimaging is not required. Seizures usually respond promptly to anticonvulsant therapy. Intellectual outcome is normal, and the epilepsy resolves after puberty. Comorbid learning difficulties and attention deficit/hyperactivity disorder (ADHD) are common.
Childhood absence epilepsy is another common syndrome. Absence seizures typically begin in the early school years and usually resolve by late childhood or adolescence. If absence does not remit, 44% will go on to develop juvenile myoclonic epilepsy (see later discussion). Ethosuximide is the first-choice therapy. A subset of patients also has generalized tonic-clonic seizures. For these children, valproic acid is the first choice as it can prevent both absence and convulsive seizures. Comorbid learning disabilities and ADHD are common. There is no contraindication to treating these children’s ADHD with stimulant medication.
Juvenile myoclonic epilepsy (of Janz) is the most common generalized epilepsy among adolescents and young adults. Onset is typically in early adolescence with myoclonic jerks (exacerbated in the morning, often causing the patient to drop objects), generalized tonic-clonic seizures, and absence seizures. Seizures usually resolve promptly with anticonvulsant medication (classically valproic acid, but several medications have been shown to be efficacious), but therapy must be maintained for life.