Diagnostic tests Illustrative samples of EEG from 14 children with<unk> . Note that spikes may be localized in any and usually multiple brain regions (multifocal spikes). Occipital spikes are common (cases 28 and 37) but these are not a prerequisite for diagnosis (cases 40, 43, 44). Cloned-like repetitive multifocal spike-wave complexes, repetitive spike or sharp and slow wave complexes that appear concurrently in different brain locations of one or both hemispheres, may be abundant (case 35). Spike location may be shifting in serial EEGs (case 44). Brief generalized discharges may occur alone or with focal spikes (case 42). The most important determinant of the neurodiagnostic procedures is the state of the child at the time of first medical attendance: (1) The child has a brief or lengthy seizure of<unk>  but fully recovers prior to arriving in the accident and emergency department or being seen by a physician. A child with the distinctive clinical features of<unk> , particularly ictus emeticus and lengthy seizures, may not need any investigations other than EEG. However, because approximately 10% to 20% of children with similar seizures may have brain pathology, an MRI may be needed. (2) The child with a typical lengthy seizure of<unk>  partially recovers while still in a postictal stage, tired, mildly confused, and drowsy on arrival to the accident and emergency department or when seen by a physician. The child should be kept under medical supervision until fully recovered, which usually occurs after a few hours of sleep. Then guidelines are the same as in (1) above. (3) The child is brought to the accident and emergency department or is seen by a physician while ictal symptoms continue. This is the most difficult and challenging situation. There may be dramatic symptoms accumulating in succession, which demand rigorous and experienced evaluation. The seizure may be very dramatic, with symptoms accumulating in succession, convulsions may occur and a child who becomes unresponsive and flaccid demands rigorous and experienced evaluation. The most prominent acute disorders in the differential diagnosis include encephalitis or an encephalopathic state from causes such as infections, metabolic derangement (either inborn error or others such as hypoglycaemia), raised intracranial pressure and so forth. A history of a previous similar seizure is reassuring and may prevent further procedures. Electroencephalography (EEG). EEG is the only investigation with abnormal results, usually showing multiple spikes in various brain locations (Figure). There is marked variability of interictal EEG findings from normal to multifocal spikes that also change significantly in serial EEGs. Occipital spikes are common but not necessary for diagnosis. Frontal or centrotemporal spikes may be the only abnormality. Generalised discharges may happen alone or together with focal spikes. A few children have consistently normal EEG, including sleep EEG. EEG abnormalities may persist for many years after clinical remission. Conversely, spikes may appear only once in successive EEGs. Series of EEGs of the same child may present with all of the above variations from normal to very abnormal. EEG abnormalities do not appear to determine clinical manifestations, duration, severity, and frequency of seizures or prognosis. There are now significant reports of ictal EEGs in 20 cases, which objectively document the seizures of<unk>  and their variable localisation at onset. All these recorded seizures occurred while the children were asleep. The onset of the electrical ictal discharge was mainly occipital (7 cases) or frontal (7 cases) and consisted of rhythmic monomorphic decelerating theta or delta activity with small spikes. The first clinical manifestation which appeared long (1–10 minutes) after the electrical onset, usually consisted of opening of the eyes as if the children were waking from sleep. At this stage, usually the children responded, often correctly, to simple questions. On many occasions, tachycardia was the first objective sign when ECG was recorded. Vomiting was a common ictal symptom occurring at any stage of the seizures but not as the first clinical manifestation. Seizures associated with ictal vomiting did not have any particular localization or lateralization. Vomiting occurred mainly when the ictal discharges were more diffuse than localized. Sometimes only retching without vomiting occurred, and on a few occasions, vomiting did not occur. Other autonomic manifestations included mydriasis, pallor, cyanosis, tachypnea, hypersalivation, and perspiration at various stages of the ictus. Of non-autonomic manifestations, deviation of eyes to the right or left occurred before or after vomiting without any apparent EEG localisation; it was present in seizures starting from the occipital or frontal regions. Magnetoencephalography (MEG). The multifocal nature of epileptogenicity in<unk>  has been also documented with MEG, which revealed that the main epileptogenic areas are along the parietal-occipital, the calcarine, or the central (rolandic) sulci. Patients with frontal spikes were significantly older than patients with spikes on rolandic, parieto-occipital, or calcarine sulci. Follow-up MEG demonstrated shifting localization or disappearance of MEG spikes. Illustrative cases In a typical presentation of<unk> , the child looks pale, vomits, and is fully conscious, able to speak, and understand but complains of “feeling sick.” Two thirds of the seizures start in sleep; the child may wake up with similar complaints while still conscious or else may be found vomiting, conscious, confused, or unresponsive. Case 1. A girl had 2 seizures in sleep at 6 years of age. In the first fit she was found vomiting vigorously, eyes turned to one side, pale, and unresponsive. Her condition remained unchanged for 3 hours before she developed generalized tonic-clonic convulsions. She gradually improved, and by the next morning was normal. The second seizure occurred 4 months later. She awoke and told her mother that she wanted to vomit, and then vomited. Within minutes her eyes turned to the right. Her mother, who was on her left, asked, "Where am I?" "There, there," the child replied, indicating to the right. Ten minutes later she closed her eyes and became unresponsive. Generalized convulsions occurred 1 hour from onset. Thereafter she recovered quickly. Her EEGs showed occipital paroxysms, but this normalized by the age of 10 years. The patient had in childhood infrequent vasovagal syncopes and/or syncope-like epileptic seizures. At last communication with her, she was 29 years of age and following a successful professional career. Case 2. This case illustrates autonomic status epilepticus with behavioral disturbances that would be difficult to attribute to seizure activity before the motor focal ictal events. A 6-year-old normal boy had a seizure at 4 years of age while traveling on a train with his parents who vividly described the event: “He was happily playing and asking questions when he started complaining that he was feeling sick, became very pale, and quiet. He did not want to drink or eat. Gradually, he was getting more and more pale, kept complaining that he felt sick, and became restless and frightened. Ten minutes from the onset, his head and eyes slowly turned to the left. The eyes were opened but fixed to the left upper corner. We called his name but he was unresponsive. He had completely gone. We tried to move his head but this was fixed to the left. There were no convulsions. This lasted for another 15 minutes, when his head and eyes returned to normal and he looked better, although he was droopy and really not there. At this stage he vomited once. In the ambulance, approximately 35 minutes from the onset, he was still not aware of what was going on, although he was able to answer simple questions with yes or no. In the hospital he slept for three quarters of an hour and gradually came around, but it took him another half to an hour before he became normal again”. EEG showed occipital paroxysms and MRI was normal. A similar prolonged episode, preceded by behavioral changes, occurred 8 months later at school. He received no medication. Since then he has been well. Case 3. This case illustrates autonomic status epilepticus with frequent vomiting witnessed from onset. An 8-year-old boy of mixed race had 2 prolonged seizures at the age of 5 years. The first seizure occurred during a brief nap. He woke up and walked with “shaking feet” to his mother, complaining that he felt sick. Within 2 to 3 minutes, his eyes and subsequently his head turned to the extreme right. His mother recalls: “I asked him to look at me, and he would not. If I moved his head to the front, it would go back to the right. Within a minute he vomited, and his eyes started blinking, and there were also tiny jerks of his body, legs, and arms that lasted for a minute. He became unresponsive to anything I said to him. He then was rigid, and he went to a deep sleep like in a coma. In the hospital he continued to be in this unconscious state, ever so often just getting up to be sick, and straight back down again. He did not start to regain consciousness or be aware of people around until about 3 hours later. He was well the
Panayiotopoulos syndrome
Fryns-Aftimos syndrome
Sotos syndrome
Cortes Lacassie syndrome
Patau syndrome
Lelis syndrome
Berk–Tabatznik syndrome
Tangier disease