Understanding Epilepsy: Basics and Classification

• Prevalence of epilepsy in developing countries higher due to parasitic illnesses
• Epilepsy deaths in Oman (2018) reached 39, representing 0.38% of total deaths
• Age-adjusted Death Rate was 0.95 per 100,000 population, ranking Oman 144th in the world
• Trigger factors for seizures include drug overdose and withdrawal, brain hemorrhage, hypocalcemia, hypoglycemia, uremia, eclampsia, and febrile seizures
• Risk factors include sleep deprivation, physical and mental exhaustion, missed doses of anti-epileptic drugs, alcohol withdrawals, recreational drug misuse, flickering lights, and intercurrent infections
• Etiology of epilepsy includes inherited/genetic causes (single gene mutation, multiple genes, genetic disorders), acquired causes (head trauma, neurosurgery, cerebrovascular diseases, infections, metabolic disorders, intracranial neoplasm), congenital causes (inborn error of metabolism), and drugs that can induce seizures
• Neurotransmitters play a role in seizures; imbalance between inhibitory neurotransmitters (GABA) and excitatory neurotransmitters (aspartate and gulumate) leads to seizures
• Classification of seizures includes focal seizures (start on one side of the brain) and generalized seizures (start in a bilaterally distributed network)
• Focal seizures have manifestations such as simple partial seizures (without impairment of consciousness, associated with motor signs, sensory and somatosensory signs, autonomic signs, and behavioral manifestations) and complex partial seizures (with impairment of consciousness, involving impaired consciousness, purposeless behaviors, aimless walking, hallucination, and aggressive behavior)
• Generalized seizures have manifestations such as absence seizures (happens exclusively in children, associated with alterations of consciousness, staring, eye-blinking, enuresis), myoclonic seizures (involuntary, rhythmic jerking of facial, limb/trunk muscles), clonic seizures (rhythmic jerking movements of the arms and legs), tonic seizures (sustained muscle contractions), generalized tonic-clonic seizures (sudden loss of consciousness, rigid body, interrupted respirations, extended legs, rapid bilateral muscle jerking, heavy salivation, tongue biting, headache, confusion, lasts for one minute), and atonic seizures (sudden loss of postural tone, falling to the ground)
• Diagnosis of epilepsy involves neurological examination/neuropsychological test, medical history, genetic history and testing, electroencephalogram (tracks electrical signals from the brain), CT and MRI scan (detects abnormalities in the brain), positron emission tomography (PET) (visualizes active areas of the brain and detects abnormalities), and functional magnetic resonance imaging (fMRI) (measures small changes in blood flow that occur in the brain). SPECT (single photon emission computerized tomography) is used when MRI and EEG did not pinpoint the location in the brain where the seizures are originating.

Learn about the epidemiology, terminology, and basic pathophysiology of epilepsy. This quiz also covers the differentiation and classification of seizure types based on clinical presentation and electroencephalogram.