Neurology and Dementia Quiz

Seizure Overview

• Seizures are sudden alterations in behavior caused by transient brain pathology.
• Symptoms vary, ranging from mild (loss of awareness) to severe (tonic-clonic).
• Some seizures are "provoked" (e.g., fever, lack of sleep, drugs, alcohol, hypoglycemia).
• Others are unprovoked, indicating more serious issues (e.g., tumors, strokes).
• Epilepsy is a medical condition defined as multiple, unprovoked seizures.

Seizure Causes by Age Group

• Children: Genetic, fever, trauma, congenital, metabolic, or infection. Juvenile myoclonic epilepsy, hyponatremia, hypernatremia, hypomagnesemia, and hypocalcemia are examples.
• Adults: Trauma, stroke, infection, or metabolic issues are common causes.
• Elderly: Stroke, tumors, metabolic issues, or infection are common causes.

Seizure Workup

• Bloodwork is often part of the evaluation; EKG for possible cardiac syncope and EEG to evaluate brain activity are also used.
• Brain imaging (CT or MRI) can pinpoint the source of the seizure.
• Lumbar puncture (LP) is sometimes necessary.

EEG (Electroencephalogram)

• Records voltage changes in the brain.
• Different leads (e.g., frontal, parietal, occipital) capture electrical activity from various brain regions.
• Characteristic patterns can reveal the presence of seizures.
• Electroencephalogram is typically normal in dementia but is abnormal with delirium.

Seizure Types

• Partial Seizures: Affect a single area of the brain.
• Simple partial: no impaired consciousness.
• Complex partial: impaired consciousness.
• Generalized Seizures: Affect all areas of the brain.
• Absence (petit mal): brief loss of awareness
• Tonic-clonic (grand mal): convulsions
• Atonic (drop seizure): loss of muscle tone
• Myotonic: muscle spasms

Psychic Symptoms

• Possible symptoms experienced during partial seizures; higher cortical areas are affected.
• Dysphasia (language problems), feelings of familiarity (déjà vu), distortions of time, fear, or hallucinations.

Autonomic Symptoms

• Epigastric "rising" sensation, common with medial temporal lobe epilepsy; sweating, piloerection, or pupillary changes.

Auras

• Warnings before major seizures, which are often simple or partial seizures.
• The aura's symptoms often correlate with the area of the brain affected (e.g., flashing lights in occipital lobe).
• Often not severe enough to disrupt consciousness.

Post-Ictal State

• Period after a seizure, where the brain recovers to its normal state
• Possible symptoms: confusion, lack of alertness, which typically resolve in minutes to hours.
• Focal neurological deficits may emerge.

Partial Seizures (continued)

• Temporal lobe is the most common seizure location.
• Mesial temporal sclerosis (also called hippocampal sclerosis) is common. It is identified neurologically due to neuronal loss in the hippocampus.
• Often bilateral, but one side may be more affected.
• Can be diagnosed with MRI scans.

Juvenile Myoclonic Epilepsy

• Absence, myoclonic, and grand mal seizures common in children.
• Absence seizures first (around 5 years), followed by myoclonic (around 15 years) eventually progressing to grand mal seizures, though often appearing together.
• Triggered by sudden awakening from sleep.
• Characterized by shock-like, irregular movements in both arms.

Childhood Absence Epilepsy

• Sudden loss of consciousness is the most prominent symptom.
• No significant change in body/motor tone is experienced.
• The occurrence is short-lived—lasting a few seconds typically—and episodic.
• Usually stops at puberty.
• Classic EEG finding; 2.5–5 Hertz spike-wave activity superimposed on normal EEG.
• No post-ictal confusion is observed.
• Ethosuximide is typically the first-line treatment but different from other epilepsy types.

Febrile Seizures

• Common in children under 5 years old (2-4% prevalence).
• Characterized by losing consciousness and jerking movements triggered by fever.
• Children at higher risk for more febrile seizures.
• Generally have a positive prognosis.
• Not considered a type of epilepsy; considered an occurrence due to an external trigger.

Eclampsia

• Pregnancy-related condition.
• Occurs from 20 weeks to 6 weeks post-partum.
• Preeclampsia (high blood pressure, proteinuria, and edema) is an indicator.
• Eclampsia features preeclampsia symptoms plus seizures.
• Treated with magnesium sulfate (MgSO4).

Seizure Treatment Principles

• Breaking seizures: Status epilepticus (continuous seizure for more than 30 minutes), or repetitive seizures within 30 minutes requires immediate medical attention.
  • Benzodiazepines (e.g., Lorazepam) are the first-line treatment.
  • Phenytoin/fosphenytoin is frequently used to prevent reoccurrence.
  • Phenobarbital can be used if seizures continue. Often require general anesthesia and intubation.
• Preventing seizures: Medication is administered to lessen the likelihood of recurrent seizures. Different classes of drugs are classified according to the mechanism they affect, including, sodium channel blockers, and GABA activators, along with other mechanisms.

Niche Drugs

• Status epilepticus: Most commonly benzodiazepines.
• Absence seizures: Ethosuximide.

Teratogenicity

• All antiepileptic drugs (AEDs) pose a risk during pregnancy.
• Valproic acid is the most teratogenic AED.
• Neural tube defects have a high risk (1-3 %).

Carbamazepine

• Inactivates sodium channels.
• Effective for partial and generalized seizures.
• Associated with many side effects(e.g., diplopia, ataxia, low blood counts, agranulocytosis, aplastic anemia, Stevens-Johnson syndrome).
• Blood levels should be monitored; can cause bone marrow suppression and liver toxicity.

Ethosuximide

• Blocks thalamic T-type calcium channels.
• Common choice for childhood absence seizures.
• Side effects include nausea, vomiting, sleep disruption, fatigue, and hyperactivity. May cause Stevens Johnson Syndrome.

Phenobarbital

• Barbiturate, binding to GABA receptors, increasing channel opening duration.
• Associated with less firing and less myocardial/respiratory depression compared to other treatment.
• Less side effects but may have excessive CNS depression if combined with alcohol. Caution in use in patients with porphyria. Induces the P450 enzyme system.

Cytochrome P450

• Important intracellular enzymes metabolizing many drugs.
• Inhibition of CYP450 leads to increased drug levels, while induction leads to decreased levels.
• AEDs can induce CYP450. Inhibitors of CYP450 can be dangerous as increased drug levels cause several complications.

P450 Drugs (examples)

• Inducers: Chronic alcohol, rifampin, phenobarbital, carbamazepine, and griseofulvin and phenytoin.
• Inhibitors: Isoniazid, erythromycin, cimetidine, azoles, grapefruit juice, and ritonavir.

Phenytoin

• Inactivates sodium channels.
• Useful for tonic-clonic seizures.
• Can lead to gingival hyperplasia, hair growth and rash.
• Folic acid supplementation and folic acid depletion are sometimes needed due to its side effects.
• Long-term use is associated with nystagmus, diplopia, and ataxia.
• Is considered teratogenic, and blood levels are important to follow. Dose-dependent hepatic metabolism is also relevant.

Valproic Acid

• Sodium and GABA effects.
• Often a mood stabilizer for bipolar disorder or acute mania.
• Not recommended for women who are pregnant; may associate with spina bifida.
• Hepatotoxicity and need for liver function monitoring (LFTS).
• Associated with tremor and weight gain.

Levetiracetam

• Exact mechanism unknown.
• Effective for many types of seizures.
• Blood levels can be monitored during treatment.
• Well tolerated; few important/serious side effects are noted.

Lamotrigine

• Sodium channel drug that can cause Stevens-Johnson Syndrome or SJS, especially in children.
• Discontinuation if rash presents.
• Affects calcium channels and has side effects such as sedation and ataxia.

Topiramate

• Affects both sodium and GABA effects. Causes mental dulling, sedation, reduced weight and kidney stones.
• Leads to more calcium in the urine, may increase the risk of kidney stones, and requires hydration to lessen the risk.

Primidone

• Mechanism of action is less understood compared to other drugs.
• Metabolized to phenobarbital.
• Can also be used for essential tremor.

Neuroembryology and other sections remain unchanged.