Failed to load latest commit information. View code. In this repo you will find resources to: Preprocessing of raw EEG data Extration time domain and frequency domain features from EEG data Implementation of five popular ML classification models selected to tackle nonlinear and imbalanced data MLP, KNN, Kernel SVM, Random Forest, AdaBoost Paper This study is based on course project paper titled ' Goal 1: Compare the performance of five popular nonlinear ML algorithms on patient-specific seizure classifications Goal 2: Compare patient-specific versus non-patient specific classification performance The complete study can be found in report.
About No description, website, or topics provided. Releases No releases published. Packages 0 No packages published. It also helps in identifying comorbidities and prognosis associated with a specific type of seizure [7]. The classification can be applied for both adult and pediatric seizures as well as epilepsies, except for neonatal seizures, classified separately [5].
Another advantage of classification includes merging both seizures and epilepsies in a single format, and the ability to classify seizures based on the available investigations in both Sarmast et al. Pharmacologically, this classification has great relevance as focal seizures, regardless of the part of the brain involved, were shown to respond to a specific set of anticonvulsants.
In contrast, drugs for generalized seizures depend on its specific type [9]. Newer Terminologies The older terminologies like convulsion, dyscognitive, simple-partial, complex-partial, psychic, and secondarily generalized were removed from the new classification due to serious criticism, as they were not completely understood by the patient or the public since these were the ones that watch the seizure event, not the physician in most of the cases [4].
Also, most of the older terminologies are not descriptive of the real seizure event; for example, the term partial means part of a seizure rather than anatomic location.
Therefore, it is replaced with a focal, which describes the locus of the seizure event localized to one cerebral hemisphere. In the same way, the term focal seizure with secondary generalization was replaced by focal to bilateral tonic-clonic terminology as it better describes the propagation pattern of the seizure [1]. Similarly, simple and complex terms are confusing to patients as simple might mean not serious to him, and complex might be taken as the only severe or difficult seizure.
Therefore, simple partial was replaced by focal aware; complex partial. Psychomotor and dyscognitive were replaced by a single term, focal impaired awareness. Grand mal was replaced by generalized tonic-clonic, focal to bilateral tonic-clonic, and unknown onset tonic-clonic; and infantile spasm replaced by epileptic spasm [1,10].
Other newer terminologies include emotional seizure, cognitive seizure, absence with eyelid myoclonia, myoclonic, atonic, focal myoclonic, focal tonic, focal epileptic spasms, behavior arrest, unaware, and unclassified seizures.
The term unconsciousness is avoided in this revised classification as it could be confusing as to whether the patient has really lost consciousness or is just not aware of what has happened around him during the event. Therefore, a new term aware was introduced because a person may be fully conscious but not aware of what happens around him [2]. Table 1 below shows the comparison between old and new terminologies. Framework of the Classification Broadly, four components are included in the new classification 1.
Seizures focal onset, generalized onset, unknown onset ; 2. Epilepsies focal, generalized, combined generalized, and focal, unknown ; 3. Epilepsy syndromes; and 4. Etiology structural, genetic, metabolic, infectious, immune, unknown. The new classification also encourages patient characterization based on the available resources like electroencephalography EEG findings, video recording, neuroimaging, or genetic workup [1].
During this revised publication, three studies were published in which two of the studies [7,11] highlighted the revised classification and the third study [10] was just a guide on how to use the revised terminology in the clinical practice [4]. A study done by Scheffer and colleagues [7] extensively discussed the revised classification of epilepsy and epilepsy syndromes, emphasizing etiology, and associated comorbidities from the point of presentation to the final stage of patient management.
Although it is mainly for epilepsy, the classification begins with classifying seizures because epilepsy is a progression of seizures [4]. A study done by Fisher et al. In this study, two categories of seizure classification have been made: basic and expanded classification. The basic classification is for general consumption by both health care professionals and the general public. In contrast, the expanded classification is meant for specialists such as neurologists, psychiatrists, neurosurgeons, or those with special expertise in epilepsy [5].
Seizure Classification and Definition of Terms In this revised classification, seizures are classified based on three features: 1. Origin of the seizure in the brain. Degree of awareness during the seizure. Level of body movement.
Based on the first feature, a seizure can be focal onset or generalized onset. The second feature implies either awareness knowledge of self and environment intact or awareness impaired while the last feature means that seizure can be motor or non-motor onset. Therefore, seizures are classified into three: Sarmast et al. However, classification based on awareness is fully optional and can be omitted, especially when it is difficult to establish the level of awareness impairment as in sudden, brief seizures [11].
The focal seizure may occur while the patient is fully aware of the events occurring around him during the seizure; this called focal aware seizures.
However, in the majority of the instances, the patient may lose awareness of some events during the seizure, and this is called focal impaired awareness.
There may be associated loss of memory amnesia during the seizure event. The term aura is commonly associated with focal seizures and can occur alone like an aura of deja vu, a strange taste or smell, or a rising sensation in the stomach, lip-smacking, and hand rubbing.
In this case, the aura is referred to as a focal aware seizure [4]. Focal seizures are named based on first signs or symptoms that appear at the beginning of the seizure, even if the later signs or symptoms are more remarkable than the first one.
The only exception is impairment of awareness, which always determines the type of the seizure even if the impairment occurs at the last phase of the seizure event. This is called the Rule of First, and clinically the first symptoms, although argued, determine the locus of the seizure [3,5]. Focal seizures occur when abnormal electrical activities originate from one side of the cerebral hemisphere, which can progress to the other side.
Awareness varies in focal seizure and can be present or absent. There may be associated jerking of a single limb arm or leg , which can progress to involve both sides of the limbs both arms and legs , where it is referred to as a focal to a bilateral tonic-clonic seizure. Generalized seizures mean that abnormal electrical activities started simultaneously from both rights and left cerebral hemispheres and then spread to the other brain neuronal networks evidenced by the patient clinical presentation or EEG features [4].
Figures below are the basic and expanded versions of the classification respectively. Table 2 below shows the types of focal motor seizures. It is repeated motor activity that usually occurs 1. Focal under impaired awareness and sometimes followed by amnesia and characterized by repeated action, Automatism such as saying something repeatedly, lip-smacking, rubbing, or wandering. It is a common feature of focal Seizure impaired awareness seizure.
Focal Seizures with loss of muscle tone that occurs suddenly and lasts for a few seconds,It can occur on one Atonic side of the body or in One limb. Awareness is usually retained. Seizures 3. Focal Seizures with a sustained increase in muscle contraction that lasts for a few seconds or minutes and Tonic present clinically as stiffening of a limb or the neck. Seizures 4. Focal Clonic Sustained rhythmical jerking of a group of muscles that occur either symmetrically or asymmetrically. Seizures Sudden uncontrolled and sometimes painful muscle contractions that commonly occur in children.
Focal Clinically present as sudden flexion of the waist and flexion or extension of the arms and legs, which may Epileptic occur in clusters and can be focal, generalized, or of unknown onset. It is usually diagnosed by video- Spasms EEG. When it occurs in infants, it is called Infantile Spasm. Focal Seizures associated with an exaggerated, and often uncontrolled muscles activities such as agitated Hyperkinetic kicking, thrashing, and peddling during the seizure.
Seizures 7. Focal It may be similar to clonic seizures but are usually brief, unsustained muscle contractions that occur Myoclonic suddenly and last for few seconds or even less than a second or just an irregular jerking in one part of the Seizures face or body. Table 3 below shows the types of focal nonmotor seizures. Focal Non-motor These are seizures affecting autonomic nervous system presenting with symptoms like rising Autonomic Seizures sensation in the stomach, hot and cold feelings, a strange taste or smell, etc 2.
Focal Non-motor These are seizures presenting with the cessation of all activities and unresponsiveness for the Behavior Arrest entire duration of the seizure event. Focal Non-motor When there are hallucinations, illusions, deja vu, or impaired speech during the seizure event, Cognitive Seizures the patient is said to have had cognitive seizures. Focal Non-motor These seizures refer to non-motor seizures that begin with panic, anxiety, fear, joy, crying, Emotional Seizures depression, or any other emotion.
Focal Non-motor These seizures present with abnormal sensations such as visual, olfactory, auditory, Sensory Seizures gustatory, somatic hallucination, or vertigo? The motor seizures include tonic-clonic, clonic, tonic, myoclonic, myoclonic-tonic-clonic, myoclonic-atonic, atonic, or epileptic spasms, whereas the non-motor are either typical or atypical absence seizures or seizures with myoclonic activity or eyelid myoclonia [3.
Most of the generalized seizures are associated with impairment of awareness, and therefore, the classification based on awareness is voluntarily omitted [6].
A Generalized motor seizure [3,4,10,11]. Table 4 below shows the types of generalized motor seizures. Seizure Types Meaning 1. Myoclonic- This seizure is usually observed in individuals with juvenile myoclonic epilepsy.
It is characterized by tonic-clonic arms jerking, then tonic stiffening, and lastly, clonic rhythmical jerking. Myoclonic- This seizure is commonly seen in patients with Doose syndrome and was previously referred to as atonic seizures myoclonic Astatic seizures. It is characterized by brief jerking of limbs or trunk, followed by a limp drop. Table 5 below shows types of generalized nonmotor seizure. Typical These seizures are characterized by interruption of activities that occur suddenly with a blank stare and Absence occasionally associated with deviation of the eyes that lasts for a few seconds to half a minute with Seizures subsequent rapid recovery.
May be associated with flicking of eyelids. Atypical It has a slow onset with significant changes in muscle tone that is more pronounced than in typical Absence absence. It has a slow spike-waves at EEG, usually less than three per second.
A myoclonic- This seizure starts with few rhythmical jerks, which is then followed by a staring spell. Eyelid In this seizure, there is sudden forceful upward jerking of eyelids, which may be associated with the staring myoclonia spell absence seizure.
It usually stimulated by the closure of the eyes. TABLE 5: Generalized Non-motor Seizures EEG: electroencephalogram Seizures of unknown onset are seizures that occur either in sleep or in a condition that cannot be described as the patient is alone or the witness cannot describe it.
After diagnosis of the seizure type, the next step is diagnosis of epilepsy type, including focal epilepsy, generalized epilepsy, combined generalized, and focal epilepsy, and also an unknown epilepsy group. The third level is that of epilepsy syndrome, where a specific syndromic diagnosis can be made. The new classification incorporates etiology along each stage, emphasizing the need to consider etiology at each step of diagnosis, as it often carries significant treatment implications.
ILAE Classification of the epilepsies
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