Seizures: Pathology review
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Seizures: Pathology review
Pathology
Central and peripheral nervous system disorders
Amyotrophic lateral sclerosis
Neurofibromatosis
Sturge-Weber syndrome
Tuberous sclerosis
von Hippel-Lindau disease
Central nervous system disorders
Brain herniation
Broca aphasia
Kluver-Bucy syndrome
Wernicke aphasia
Wernicke-Korsakoff syndrome
Acoustic neuroma (schwannoma)
Adult brain tumors
Pediatric brain tumors
Pituitary adenoma
Ischemic stroke
Transient ischemic attack
Brain abscess
Cavernous sinus thrombosis
Creutzfeldt-Jakob disease
Encephalitis
Epidural abscess
Meningitis
Neonatal meningitis
Aqueductal stenosis
Cerebral palsy
Chiari malformation
Dandy-Walker malformation
Septo-optic dysplasia
Spina bifida
Spinocerebellar ataxia (NORD)
Syringomyelia
Tethered spinal cord syndrome
Alzheimer disease
Creutzfeldt-Jakob disease
Delirium
Frontotemporal dementia
Lewy body dementia
Normal pressure hydrocephalus
Vascular dementia
Acute disseminated encephalomyelitis
Central pontine myelinolysis
JC virus (Progressive multifocal leukoencephalopathy)
Multiple sclerosis
Transverse myelitis
Cavernous sinus thrombosis
Cluster headache
Idiopathic intracranial hypertension
Migraine
Tension headache
Trigeminal neuralgia
Arteriovenous malformation
Epidural hematoma
Intracerebral hemorrhage
Saccular aneurysm
Subarachnoid hemorrhage
Subdural hematoma
Essential tremor
Huntington disease
Opsoclonus myoclonus syndrome (NORD)
Parkinson disease
Restless legs syndrome
Torticollis
Early infantile epileptic encephalopathy (NORD)
Epilepsy
Febrile seizure
Brown-Sequard Syndrome
Cauda equina syndrome
Friedreich ataxia
Neurogenic bladder
Syringomyelia
Treponema pallidum (Syphilis)
Vitamin B12 deficiency
Concussion and traumatic brain injury
Peripheral nervous system disorders
Poliovirus
Spinal muscular atrophy
Charcot-Marie-Tooth disease
Guillain-Barre syndrome
Bell palsy
Trigeminal neuralgia
Carpal tunnel syndrome
Erb-Duchenne palsy
Klumpke paralysis
Sciatica
Thoracic outlet syndrome
Ulnar claw
Winged scapula
Lambert-Eaton myasthenic syndrome
Myasthenia gravis
Nervous system pathology review
Adult brain tumors: Pathology review
Central nervous system infections: Pathology review
Cerebral vascular disease: Pathology review
Congenital neurological disorders: Pathology review
Dementia: Pathology review
Demyelinating disorders: Pathology review
Headaches: Pathology review
Movement disorders: Pathology review
Neurocutaneous disorders: Pathology review
Neuromuscular junction disorders: Pathology review
Pediatric brain tumors: Pathology review
Seizures: Pathology review
Spinal cord disorders: Pathology review
Traumatic brain injury: Pathology review
Assessments
Seizures: Pathology review
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Transcript
Content Reviewers
On the neurology ward, a 7-year old male, called Stefan, is brought by his mother. His mother is worried because he has several episodes every day where he loses consciousness for a few seconds. His teacher also complains that she often catches him daydreaming during the lesson. Next to Stefan, there’s a 17-year old male, called Jacob, who seems sluggish and tired. His friends brought him because he suddenly started “shaking and jerking” and he lost consciousness for about two minutes. His medical history is otherwise insignificant. Now, there’s also an 11-year old female, called Megan, who also seems lethargic. Her father is very upset because he witnessed an episode of twitching of her left foot that lasted a few minutes. Megan was unconscious and has no memory of the event. Finally, there’s a 19-year old female, called Joanna, that has had repetitive episodes of sudden and rapid jerking movements with loss of consciousness for the past few months. They usually occur when she wakes up in the morning and especially during periods of sleep deprivation.
Okay, so all of them had a seizure episode. A seizure is a paroxysmal motor, sensory or autonomic event that occurs due to abnormal, excessive and synchronous electrical discharges from neurons in the brain. Seizures usually last less than 5 minutes. If it lasts more than 5 minutes, it’s called status epilepticus. Epilepsy is a chronic disease of the brain that predisposes an individual to having recurrent unprovoked seizures; that is seizures without a clear triggering cause. Epilepsy is typically diagnosed when an individual has two or more unprovoked seizures separated by at least twenty-four hours.
Okay, now seizures are broadly classified into two types, generalized and focal seizures. Generalized seizures arise from both cerebral hemispheres at the same time, while focal seizures arise from specific areas in one cerebral hemisphere. However, focal seizures can spread to both cerebral hemispheres, causing a generalized seizure. When this happens, it’s appropriately called secondary generalization of a focal seizure.
Summary
A seizure is a paroxysmal event due to abnormal electrical activity in the brain that can cause changes in behavior, consciousness, or movement. A seizure shouldn't be confused with epilepsy, which is said when two or more unprovoked seizures occur. Epilepsy is a chronic disorder that predisposes the individual to have recurrent seizures, and can't be diagnosed based on a single episode of seizures alone.
Seizures can be classified into generalized and focal seizures. Generalized seizures arise from both cerebral hemispheres at the same time, and almost always cause a sudden impairment of consciousness; whereas focal seizures arise from specific areas in one cerebral hemisphere, and present as a dysfunction of the part of the body controlled by the affected part of the brain.
When evaluating an individual with seizures, it's first important to identify the possible trigger. Diagnostic tests such as a CBC (complete blood count), electrolytes, liver function tests, and glucose levels, must be done to reveal potential causes. An EEG (electroencephalography) can also be done to assess the type of seizure. Treatment for seizures may involve supportive therapy, treating the underlying causes when possible, and antiseizure medications to manage convulsions.
Sources
- "Robbins Basic Pathology" Elsevier (2017)
- "Harrison's Principles of Internal Medicine, Twentieth Edition (Vol.1 & Vol.2)" McGraw-Hill Education / Medical (2018)
- "CURRENT Medical Diagnosis and Treatment 2020" McGraw-Hill Education / Medical (2019)
- "DeGowin's Diagnostic Examination, Tenth Edition" McGraw-Hill Education / Medical (2014)
- "Epilepsy" Lippincott Williams & Wilkins (2007)
- "Cochrane Database of Systematic Reviews" undefined (undefined)
- "Ion Channel Genes and Epilepsy: Functional Alteration, Pathogenic Potential, and Mechanism of Epilepsy" Neuroscience Bulletin (2017)
- "The Blood?Brain Barrier and Epilepsy" Epilepsia (2006)
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