What kind of seizures may occur in refractory epilepsy?
Refractory epilepsy has a variety of clinical seizure types, mostly generalized seizures and complex partial seizures, mainly manifested as frottage and generalized tonic convulsions, while a few are dominated by simple partial seizures, mostly in the form of simple partial seizure continuity, mainly manifested as a single hand or foot twitch.
What syndromes do refractory epilepsy often present as?
According to the etiology and performance of refractory epilepsy, it can be broadly divided into three major categories.
1. Refractory epilepsy syndromes.
Epileptic syndromes are different from common epilepsy in that they have a special etiology pathogenesis clinical manifestations treatment methods and evolutionary patterns
The International League Against Epilepsy identifies epileptic syndromes as epilepsies consisting of specific symptoms and signs. The main reported refractory epileptic syndromes are: early infantile epileptic encephalopathy, infantile spasms, Lennox-Gastaut syndrome, persistent partial epilepsy, Sturge-Weber syndrome, Rasmussen syndrome, Otahara syndrome, severe myoclonic epilepsy in infancy, tuberous sclerosis, medial temporal lobe epilepsy and certain types of myoclonic epilepsy syndromes, etc.
2. Special causes of symptomatic epilepsy.
Tumor trauma, vascular malformation cerebrovascular disease various metabolic diseases hypoxic developmental abnormalities infection parasites nutritional disorders endocrine disorders and certain drugs can cause seizures, these have a clear cause of epilepsy is called symptomatic epilepsy.
3. Idiopathic or cryptogenic epilepsy.
This type of intractable epilepsy is initially only common epilepsy, but in the process of diagnosis and treatment due to diagnostic errors improper drug selection non-compliance adverse drug reactions learning difficulties economic problems and insufficient social help for epileptic patients and many other reasons make seizures uncontrolled for a long time, and finally develop into intractable epilepsy, which is the result of poor treatment. A small number of patients are part of refractory epilepsy because of drug gene mutations or innate tolerance to drugs due to individual factors that make traditional drugs difficult to work.
What are the necessary tests needed to diagnose refractory epilepsy?
Often refractory epilepsy is difficult to determine the cause and location of the epileptic focus through general tests, so special tests are required.
1. PET.
Fully known as positron emission tomography, it is used to examine and localize the site of metabolic changes in the brain during intermittent or seizure periods to identify the epileptogenic focus, which is used to assess the feasibility of resective surgery.
2. MEG.
That is, magnetoencephalography, which is used to observe the location of abnormal discharges by capturing the magnetic field generated by spontaneous discharges in the brain to identify the epileptogenic focus, and is also used to assess whether resection surgery is feasible.
3. WADA experiment.
It is an invasive test to determine the dominant cerebral hemisphere before epilepsy surgery, and is used to determine the distribution of language and other important functions in the cerebral hemisphere before preparing for hemispherectomy, temporal lobectomy, and resection of epileptic foci, and to determine the surgical approach. The procedure is used to determine the surgical method by understanding the distribution of speech and other important functions in the cerebral hemisphere.
4. Intracranial electrode implantation Scalp EEG errors are large, making it difficult to accurately determine the location or even lateralization of epileptic foci, or when patients have multiple suspected epileptic foci, it is usually necessary to implant intracranial electrodes for detection to accurately locate the epileptic foci and improve the resection rate of the epileptogenic foci, as well as to determine the function of the corresponding regions via their stimulated cortex, thus avoiding resection complications.
How is a diagnosis of refractory epilepsy confirmed?
Clinically, refractory epilepsy is divided into two types: medically induced (pseudo) and truly refractory. In the former case, the seizures are not controlled due to incorrect diagnosis, incorrect seizure typing, failure to select the right antiepileptic drug or inadequate dose of the right drug, while in the latter case, the seizures are recurrent despite correct diagnosis, appropriate dose and blood concentration.
The latter refers to recurrent seizures despite correct diagnosis, appropriate dosage and blood levels. Seizure conditions are classified into 7 grades from 0 to 6: Grade 0: only 1 non-first-line drug is used independent of dose; Grade 1: first-line antiepileptic drug is used but the dose is lower than recommended; Grade 2: first-line drug but the dose is within the recommended range; Grade 3: first-line drug with blood drug concentration within the therapeutic range; Grade 4: first-line antiepileptic drug with maximum tolerated dose applied; Grade 5: more than 1 antiepileptic drug with maximum tolerated dose. Grade 6.
Maximum tolerated dose of more than one combination of drugs. Of these, grades 0 to 2 are medical in origin, caused by inadequate doses of non-first-line drugs or insufficient drug concentrations in plasma or inappropriate treatment, and grades 3 to 6 are considered refractory epilepsy.
Truly refractory epilepsy should exclude the following factors.
1. seizures that are not accurately typed and for which drug therapy may lack specificity.
2. doses used that do not reach the maximum tolerated limit, although the choice of medication is reasonable.
3. The efficacy of the treatment is compromised by the lack of compliance of the patient due to the excessive number of combination drugs, inappropriate dosage form and dosing regimen; 4. Non-epileptic seizures but other disorders such as motor disorders manifesting as epileptic seizures psychogenic convulsions sleep disorders, when the application of AEDs is ineffective and may also worsen the condition.