Content on this page:
Content on this page:
Clinical Presentation
Clinical Symptoms (During Seizure)
Epilepsy_Initial Assesment 1The clinical symptoms of epilepsy during seizure are aura, cyanosis, sudden falls, motor symptoms (involuntary stiffening or jerky movements of limbs in an awake, unaware or asleep patient), cognitive symptoms (blank spells, speech arrest with or without automatisms), sensory symptoms (paresthesia or numbness, auditory, olfactory or visual hallucination), autonomic symptoms (urinary incontinence or tongue biting with loss of awareness, or during sleep), and alteration of mental status (episodes of confused behavior with lack or loss of awareness and/or recollection).
History
The history should include but is not limited to age of onset, description of attack from patient and witness, family history, social history, alcohol and drug use, past medical history including head injury, febrile convulsions and diseases in other organ systems. A clear history from the patient and a witness to the attack is the most important diagnostic information and should be the mainstay of diagnosis.
Physical Examination
Physical examination is done to detect signs of disorder associated with epileptic seizures (eg sign of head trauma, ear or sinus infection, congenital abnormalities, focal or diffuse neurologic abnormalities, or diseases in other organ systems).
Diagnosis or Diagnostic Criteria
Seizure Description
The patient should describe in detail the frequency of attacks, triggering factors, symptoms before, during and after the attacks, duration of symptoms, injury incurred and incontinence. Witnesses should describe in detail: The frequency of attacks, detailed observations before and during the attacks (eg physical symptoms, psychic symptoms and level of consciousness) and the symptoms following the attacks.
It is recommended that all patients having a first seizure be referred as soon as possible to a specialist to ensure accurate and early diagnosis and the initiation of treatment appropriate to the needs of the patients.
Investigate Triggering Factors
Triggering factors of seizures are visual stimulation (eg photic stimulation), sleep deprivation, hyperventilation, fatigue, stress, hypoxia, and alcohol intake/withdrawal.
Levels of Diagnosing Epilepsy
The levels of diagnosing epilepsy depend on the seizure type, epilepsy type, and epilepsy syndrome wherein a specific syndromic diagnosis can be made.
Seizure Types
Focal Onset
In focal onset, only one portion of the brain, typically part of one lobe of one hemisphere, is involved. This can be subcategorized to aware and impaired awareness and can also be subgrouped to motor and non-motor signs and symptoms. Retained awareness is when the patient is aware, even if immobile, of self and environment during the seizure. Impaired awareness is having any significant impairment of awareness during the course of the seizure. Focal aware seizure replaced the previous term simple partial seizure. Focal impaired awareness seizure replaced the previous term complex partial seizure. Seizure classification should be based on the earliest prominent motor onset or non-motor onset feature. New focal onset seizure types include automatisms, autonomic, behavior arrest, cognitive, emotional, hyperkinetic, sensory and focal bilateral tonic-clonic seizures. Focal to bilateral tonic-clonic is a special type of seizure that was previously termed partial onset with secondary generalization.
Epilepsy_Initial Assesment 2Generalized Onset
In generalized onset, nearly always consciousness is lost except in myoclonic seizures and clinical features together with electroencephalographic changes indicate involvement of bilateral hemispheres of the brain at the onset of seizure. Motor seizures are subdivided into myoclonic (single or multiple jerks, often upper limbs), tonic, tonic-clonic, clonic, atonic (sudden loss of muscle tone of the head, limbs and/or body), myoclonic-atonic, myoclonic-tonic-clonic, and epileptic spasms. Non-motor (absence) seizures are subdivided to typical, atypical, tonic-clonic, myoclonic, and eyelid myoclonia.
Unknown Onset
An unknown onset is an onset of seizure that may be missed or obscured. Motor unknown onset seizures can be subgrouped as epileptic spasms (includes infantile spasm) and tonic-clonic. Non-motor unknown onset seizure subgroup is behavior arrest.
Epilepsy Types
Generalized Epilepsy
Electroencephalogram shows generalized spike-wave activity in generalized epilepsy. This may have a range of seizure types that include absence, myoclonic, atonic, tonic and tonic-clonic seizures.
Idiopathic/Genetic Generalized Epilepsy
Idiopathic epilepsy is a well-recognized and common subgroup of generalized epilepsy. It encompasses well-established epilepsy syndromes: Childhood absence epilepsy, juvenile absence epilepsy, juvenile myoclonic epilepsy and generalized tonic-clonic seizures alone.
Focal Epilepsy
The diagnosis of focal epilepsy is made on clinical findings together with electroencephalogram findings of focal epileptiform discharges. This includes unifocal and multifocal disorders as well as seizures involving one hemisphere. The range of seizure types that can be seen include focal aware seizures, focal impaired awareness seizures, focal motor seizures, focal non-motor seizures, focal to bilateral tonic-clonic seizures.
Combined Generalized and Focal Epilepsy
Patients are characterized as having both generalized and focal seizures. The diagnosis is based on clinical findings with electroencephalogram findings of both generalized spike-wave and focal epileptiform discharges but epileptiform activity is not required for diagnosis.
Unknown Epilepsy
Unknown epilepsy are patients who have epilepsy, but the clinician is unable to determine if the epilepsy type is focal or generalized due to insufficient information available.
Epilepsy Syndrome
Epilepsy syndrome is a cluster of features that incorporate seizure types, electroencephalography findings, and imaging features that tend to occur together. Age-dependent features that are commonly found are age at onset and remission, seizure triggers, diurnal variation and sometimes prognosis. It serves as a guide to management as it does not have a one-to-one correlation with an etiologic diagnosis. Well-recognized syndromes are childhood absence epilepsy, West syndrome, Dravet syndrome and Lennox- Gastaut syndrome. Dravet syndrome is a rare genetic ерilepѕу syndrome characterized by refractory ерileрѕy and neurodevelopmental problems that begins during infancy. Lennox-Gastaut syndrome is a lifelong condition associated with the onset of severe ѕеizurеs in chilldhоοd, treatment-resistant ерileрѕy and intellectual disability.
Determine Etiology
From the moment that the patient presents with a first epileptic seizure, the clinician should aim to determine the etiology of the patient’s epilepsy. Determine the disease associated with the epileptic seizure or syndrome (eg neurocutaneous diseases, malformations, tumors, chromosomal anomalies, monogenic Mendelian diseases, etc). Often the first investigation carried out involves neuroimaging, ideally MRI if available. This enables the clinician to decide if there is a structural etiology for the patient’s epilepsy. Other etiologies include genetic, infectious, metabolic, immune and unknown.
Electroclinical Syndromes and Other Epilepsies
Electroclinical Syndrome
Electroclinical syndrome is a complex of clinical features, symptoms and signs defined by a group of electroclinical characteristics. This is classified based on typical age of onset, EEG findings, type of seizure, and other characteristics which allow for a specific diagnosis. One example is electroclinical syndromes arranged by age of onset: Neonatal period (eg early myoclonic encephalopathy (EME), benign familial neonatal epilepsy [BFNE]); infancy (eg West syndrome, benign infantile epilepsy, epilepsy of infancy with migrating focal seizures, myoclonic epilepsy in infancy [MEI]); childhood (eg epilepsy with myoclonic atonic seizures, epilepsy with myoclonic absences, febrile seizures plus [FS+], electrical status epilepticus during slow sleep [ESES]); adolescence to adulthood (eg juvenile myoclonic epilepsy [JME], juvenile absence epilepsy [JAE], epilepsy with generalized tonic-clonic seizures alone, progressive myoclonus epilepsies [PME]); and less specific age relationship (eg reflex epilepsies, familial focal epilepsy with variable foci [childhood to adult]).
Distinctive Constellations
Examples of distinctive constellations are Rasmussen syndrome, mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE with HS), hemiconvulsion-hemiplegia-epilepsy, and gelastic seizures with hypothalamic hamartoma. These represent clinically distinct groupings or constellations based on specific lesions or other causes. The age at presentation is not a defining feature. Epilepsies that do not fall into any of these groups can be identified by the presence or absence of a known metabolic or structural condition and the primary means of seizure onset (focal versus generalized).