Panayiotopoulos syndrome (named after C. P. Panayiotopoulos) is a common idiopathic childhood-related seizure disorder that occurs exclusively in otherwise normal children (idiopathic epilepsy) and manifests mainly with autonomic epileptic seizures and autonomic status epilepticus. An expert consensus has defined Panayiotopoulos syndrome as "a benign age-related focal seizure disorder occurring in early and mid-childhood. It is characterized by seizures, often prolonged, with predominantly autonomic symptoms, and by an EEG [electroencephalogram] that shows shifting and/or multiple foci, often with occipital predominance."
Signs and symptoms Panayiotopoulos syndrome occurs exclusively in otherwise normal children and manifests mainly with infrequent autonomic epileptic seizures and autonomic status epilepticus. Onset of seizures is from age 1 to 14 years with 76% starting between 3–6 years. Autonomic seizures consist of episodes of disturbed autonomic function with nausea, retching and vomiting as predominant symptoms. Other autonomic manifestations include pallor (or, less often, flushing or cyanosis), mydriasis (or, less often, miosis), cardiorespiratory and thermoregulatory alterations, incontinence of urine and/or feces, hypersalivation, and modifications of intestinal motility. In approximately one fifth of the seizures the child becomes unresponsive and flaccid (syncope-like epileptic seizures or ictal syncope) before or often without convulsions. Syncope-like epileptic seizures (ictal syncope) with the child becoming "completely unresponsive and flaccid like a rag doll" occur in one fifth of the seizures. More-conventional seizure symptoms often appear after the onset of autonomic manifestations. The child, who was initially fully conscious, becomes confused and unresponsive. Eyes turn to one side or gaze widely open. Only half of the seizures end with brief hemiconvulsions or generalized convulsions. Autonomic symptoms may be the only features of the seizures. None of the above symptoms alone is a prerequisite for diagnosis. Recurrent seizures may not be stereotyped. The same child may have brief or prolonged seizures and autonomic manifestations may be severe or inconspicuous. The full emetic triad (nausea, retching, vomiting) culminates in vomiting in 74% of the seizures; in others only nausea or retching occur, and in a few, none of the emetic symptoms are apparent. Most of the seizures are prolonged and half of them last more than 30 minutes thus constituting autonomic status epilepticus, which is the more common nonconvulsive status epilepticus in normal children. Characteristically, even after the most severe seizures and autonomic status epilepticus, the child is normal after a few hours of sleep, which is both diagnostic and reassuring. However, it has been recently reported that sometime after status epilepticus in children with Panayiotopoulos syndrome the growth of the frontal and prefrontal lobes is slightly decreased and the scores on neuropsychological tests is decreased. Focal onset hemiconvulsions or generalised convulsions occur in nearly half of the seizures. These are usually shorter than the preceding autonomic manifestations but in a few cases they may be prolonged constituting convulsive status epilepticus or the preceding autonomic manifestations are brief and not apparent Seizures can occur at any time but they are more common during sleep.
Cause Panayiotopoulos syndrome is probably genetically determined, though conventional genetic influences may be less important than other mechanisms. Usually, there is no family history of similar seizures, although siblings with Panayiotopoulos syndrome or Panayiotopoulos syndrome and rolandic epilepsy or, less common, Panayiotopoulos syndrome and idiopathic childhood occipital epilepsy of Gastaut have been reported. There is a high prevalence of febrile seizures (about 17%). SCN1A mutations have been reported in a child and in 2 siblings with relatively early onset of seizures, prolonged time over which many seizures have occurred, and strong association of seizures with febrile precipitants even after the age of 5 years. However, no such mutations were found in another couple of siblings and many other cases with typical Panayiotopoulos syndrome. These data indicate that SCN1A mutations when found contribute to a more severe clinical phenotype of Panayiotopoulos syndrome.
Pathophysiology In Panayiotopoulos syndrome there is a diffuse multifocal cortical hyperexcitability, which is age (maturation)-related. This diffuse epileptogenicity may be unequally distributed, predominating in one area, which is often posterior. Epileptic discharges in Panayiotopoulos syndrome, irrespective of their location at onset, activate emetic and autonomic centers prior to any other conventional neocortical seizure manifestations. An explanation for this is that children are susceptible to autonomic disorders as illustrated by the cyclic vomiting syndrome, which is a nonepileptic condition specific to childhood. Panayiotopoulos syndrome and all other benign childhood focal seizures, with rolandic epilepsy as their main representative, are probably linked due to a common, genetically determined, mild, and reversible functional derangement of the brain cortical maturational process that Panayiotopoulos proposed as "benign childhood seizure susceptibility syndrome". The various EEG and seizure manifestations often follow an age- (maturation-) related localization. Panayiotopoulos syndrome is probably the early onset phenotype of the benign childhood seizure susceptibility syndrome. During a recorded autonomic seizure, there was a small increase in blood pressure (+5/4 mm Hg, systolic/diastolic), pronounced increases in heart rate (+59 bpm) and plasma concentrations of norepinephrine (+242 pg/mL), epinephrine (+175 pg/mL), and vasopressin (+22.1 pg/mL); serum glucose was also elevated (206 mg/dL). The significant increase in plasma vasopressin may explain the emetic autonomic symptoms.
Diagnosis
Diagnostic tests
… excerpt ends here. Continue reading the full article.
