Paediatrics: Epilepsies: mid to late childhood (2)

2021-03-02 12:00 AM

The term idiopathic focal epilepsy, or benign focal epilepsy, is used less frequently due to the severity of the seizures in some children.

Epilepsies: mid to late childhood (2)

Idiopathic focal epilepsies

The term idiopathic focal epilepsy, or benign focal epilepsy, is used less frequently due to the severity of the seizures in some children. 

Benign childhood epilepsy with centrotemporal spikes—Rolandic Epilepsy’

The classic presentation of this condition is:

  • Predominantly nocturnal sensorimotor seizures.
  •  Onset in one side of the face or a hand, then spreading down one side and may generalize.
  •  EEG may be relatively normal whilst awake.
  •  EEG in slow-wave sleep or drowsiness will develop frequent centrotemporal spike and wave discharges with an easily recognizable shape and distribution.

The majority of children with this condition have infrequent, short seizures and the decision of whether to treat or not is taken after discussion with the parents and child. Some clinicians feel strongly that therapy should be the same as in idiopathic generalized epilepsy, but others will consider using carbamazepine.

 

Benign childhood occipital seizure syndrome (Panayiotopoulos syndrome)

  •  Young children (aged 1–7yrs).
  •  Bizarre seizures: prolonged (<30min), stereotyped episodes of encephalopathy often associated with ictal vomiting, headache, and eye deviation.
  •  Often misdiagnosed.
  •  Heterogeneous EEG abnormalities.
  •  Good prognosis.
  •  Treatment is rarely indicated.

Landau–Kleffner syndrome (LKS) and electrical status in slow-wave sleep

These conditions are considered to be an extreme variant, marked by the following:

  • Intellectual regression with relatively few seizures.
  •  Striking language impairment—epileptic aphasia in LKS.
  •  EEG may show non-specific abnormalities in the waking state, but once drowsy or in slow-wave sleep the EEG develops electrical status.

 They are difficult to treat and normally refractory to first-line drugs.

 Steroids are advocated and have been shown to be of temporary benefit.

They may even improve long-term outcome.

Focal epilepsies

These epilepsies are symptomatic of a focal area of dysfunction, but the electrical discharges may generalize (i.e. secondary generalization).

  • While the electrical discharges are focal, consciousness may be maintained (previously known as simple partial seizures).
  • When the discharges become more widespread consciousness will be impaired or lost (previously known as complex partial seizures).
  • They all may develop into a secondarily generalized seizure. At that point, it is not possible to classify them if the onset has not been witnessed.
  • Their expression will depend on the principally affected area of the brain.

Frontal lobe epilepsies

These children tend to have short, but frequent seizures—particularly arising out of sleep. They are often associated with asymmetric dystonic posturing and brought on by loud noises. Recovery can be quick and they may be difficult to assess on the EEG.

Temporal lobe epilepsies

The seizures affect memory and emotion with disturbances such as ‘déjà vu’, fear, abdominal discomfort, and automatisms.

Occipital lobe epilepsies

These episodes are associated with simple multicoloured blobs of light in one side of a visual field. They often produce headache and vomiting.

Management of focal epilepsies

Investigation

MRI is always indicated. Children rarely have malignant brain tumours. However, they can have dysplasias, gliosis, and benign tumours. The temporal lobe may show hippocampal sclerosis.

Treatment

  •  First-line: carbamazepine is generally recommended.

Second-line: therapy is widely debated. There are few good studies comparing anti-epileptic drugs against each other. However, sodium valproate is a logical choice amongst the older anticonvulsants (but not in girls >9yrs of age). Of the newer anticonvulsants, lamotrigine, topiramate, and levetiracetam could be used, but licensing conditions should be noted.