Epilepsy, Periodic Paralyses And Strokes Most Common Neurological Comorbidities Of Migraine Headaches In Children
Migraines in children and adolescents occur jointly with other neurological, psychiatric or somatic diseases with above-average frequency. Epilepsy, various disorders caused by cellular ion channels malfunction (channelopathies) and multiple sclerosis deserve special mention in this regard in the field of neurology. In addition, strokes occur in children with migraines twice as often as in conjunction with smoking, adiposity, use of oral contraceptives or other risk factors. Only limited research has been done on the frequency of these comorbidities thus far yet it indicates patterns of origin. Dr Ana Potic (University of Belgrade, Serbia) reported on these patterns at the 23rd Meeting of the European Neurological Society (ENS) in Barcelona. More than 3,000 experts are discussing current developments in their field at this congress.
The team headed up by Dr Potic examined 40 children simultaneously suffering from migraines and one or more other neurological disorders. Findings were analysed over a period of ten years for a total of 22 girls and 18 boys. The children averaged eleven years old at the time of their first examination. A primary focal or generalised form of epilepsy was detected in 20 of the children, i.e. in one out of every two children. This condition was followed in frequency by periodic paralyses with involuntary prolonged muscle contraction (myotonia), which occurred in six of the young patients. Five subjects were diagnosed as having ischaemic strokes while three children each were found to suffer from movement disorders such as paroxysmal dystonia and periodic ataxias. Multiple sclerosis was detected as an accompanying disorder in two of the young patients and one patient was found to have a mitochondrial disorder.
Possible causes of migraines
Dr Potic: “Larger studies confirm the findings and also point to possible factors that could influence the cause, origin and development of migraines and the diseases that accompany them.” In the case of migraines and epilepsy, for example, plausible causes are changes in ion transport in the neuronal cell membranes that interfere with the excitability of the nerve cells. Although scant thus far, the evidence for migraines and strokes indicates that possible triggers might be the processes that change the flow of blood in the brain. If migraines are accompanied by mitochondrial encephalopathy, however, this state might be attributable to changes in the excitability of nerve cells connected, for example, with malfunctions in cellular metabolism and neuronal tissue damage.
For multiple sclerosis, some studies say that the lack of myelin in lesions in the cerebral cortex caused by MS is what triggers the processes responsible for the start of a migraine attack, Dr Potic said. Other studies view the trigger of migraines to be in the structural lesions that MS can initiate in certain regions of the mid-brain, specifically the nucleus ruber, the substantia nigra and the substantia grisea periaquaeductalis. Previous research has yielded little evidence that holds up to scrutiny in this regard and with regard to the processes for the other neurological disorders accompanying migraines.
“In the still open question as to how migraine attacks are triggered, the current study findings support the thesis of so-called cortical spreading depression”, Dr Potic said. This phenomenon can be observed by means of functional magnetic resonance tomography. An electrical hyperactivity of the cells in the cerebral cortex spreads from its initial point of origin. In the process, the blood vessels contract, thereby forming a blockade and activating the trigeminal vascular system. The neurotransmitters noradrenaline and serotonin generated in the brain stem ensure that the process continues and that the trigeminal nerve remains hypersensitive. This hypersensitivity is subsequently perceived as a headache.
Precise diagnosis important
Migraines in children often take highly complex forms. Precise and correct diagnosis of this disorder is crucial for preventing co-morbidities and consequential morbidities to the greatest possible extent. Dr Potic: “It is important to distinguish between the individual types of migraines and other neurological disorders which can often strongly resemble each other in clinical appearance.” Once the migraine is confirmed and is able to be clearly distinguished from any accompanying disorder, caution should also be applied in the treatment. The child neurologist went on to say: “The rule of thumb is not to select a migraine drug that could have an adverse effect on an accompanying disease and vice versa. In addition, you have to watch out for possible interactions whenever multiple active ingredients affecting both migraine and accompanying disorder are involved.” Drugs treating both conditions are always the means of choice.
ENS Abstract P949: Neurological comorbidities in children and adolescents with migraine headache
European Neurological Society