Presentation on theme: "Seizures Diagnosis and Management"— Presentation transcript:
1Seizures Diagnosis and Management Nisha Kanani, David Cherney2004
2ResourcesPrimary Care: Epilepsy. Browne T. R., Holmes G. L. NEJM; 344: , Apr 12, 2001.Current Concepts: Patients with refractory seizures. Devinsky O. NEJM; 340: , May 20, 1999Consensus statements: Medical management of epilepsy. Neurology; 51(5 suppl4): S39-43, NovTextbook of clinical neurology. GreenbergCanadian Driving Guidelines Online
3Objectives First seizure evaluation in adults Seizure classification 3. Management options
4Case32 y/o male taxi-driver is referred for evaluation of a “spell” while walking to the corner store, after which he was found on the ground.Brought in by EMS to the ERSubsequently sent homeWhat are you going to do and tell the patient?
5DefinitionsSeizure: transient disturbance in cerebral function caused by abnormal neuronal dischargeEpilepsy: group of disorders represented by recurrent seizures (3% lifetime prevalence)
6Evaluating seizures: Is this a seizure? What type of seizure is this? (implications on treatment)Is there an underlying cause?
7Is this a Seizure? Seizure Mimics: Classic migrainesinclude transient neurologic symptoms (as in partial seizures).epilepsy patients twice as likely to have migraines.SyncopePostural, flaccid paralysis, pre-syncope symptoms, no post-ictal stateMay have fasiculations (convulsive syncope)TIAUsually no LOC unless basilar stroke, usually negative findings not positive. Sometimes confusing if post-ictal Todd’s paralysisPseudo-seizures10-45% of patients with refractory epilepsy. Look for history of abuse. Patients can have both.5) Movement disorders
9Is there an underlying cause? (rule out secondary causes of seizures)1o neurologic disorderSystemic disorderHead traumaCancerHemorrageStrokeVascular malformationsMeningitis/encephalitisHypoglycemiaHyponatremiaHypocalcemiaUremiaHepatic encephalopathyDrug OD/withdrawalHyperosmolar statesHyperthermia
10History Witness testimony is key! Triggers, ictal behaviors, LOC, behaviour during seizure and the postictal state.Seizure precipitants or triggers:strong emotions, intense exercise, flashing lights, and loud music (often immediately before the seizure)fever, menstruation, lack of sleep, and stress
11HistoryAsk about . . .Drugs, alcohol, constitutional symptoms, HIV risk factors, fever, head trauma.Family History (absence and myoclonic seizures may be inherited)
12Physical examination Generally unrevealing Look for signs of disorders associated with seizures.Head trauma, meningismus, sinus infection.Focal or diffuse neurological abnormalities.Mental status abnormalities suggest lesions in the anterior frontal, parietal, or temporal lobes.Evaluate for lateralizing abnormalities: weakness, hyperreflexia, positive Babinski sign
13Laboratory evaluation Glucose, calcium, magnesium, hematology studies, renal function tests, lytes toxicology screens.Acute postictal changes: metabolic acidosis and leukocytosis, high CKLP if risk factors for infection (fever, HIV positive).
14Electroencephalography Information provided:Presence of abnormal electrical activityInformation of type of seizure disorderLocation of seizure focusPerform study >48hrs after seizureInclude recordings during sleep, photic stimulation, hyperventilation.50% of patients with epilepsy have normal single EEG
15Electroencephalography If normal and high suspicion, repeat study after sleep deprivation10% of persons with true seizure with have normal multiple EEG studies+EEG likelihood of second seizure over two years
16Neuroimaging in adults with 1st seizure Retrospective review of 148 patients studied within 30 days of the seizureStructural lesion was identified by CT in 55 (37 percent); 16 (11 percent) had metabolic seizuresCT findings agreed with the results of neurological examination in 82 percent of cases.Ramirez-Lassepas, et al. Value of computed tomographic scan in the evaluation of adult patients after their first seizure. Ann Neurol 1984; 15:536.
17Neuroimaging All patients should receive neuroimaging. MRI preferred over CT to identify small lesions such as cortical dysplasias, infarcts, or tumors.CT scan is suitable in emergency situations to exclude a mass lesion, hemorrhage, or large stroke.
18When to initiate Antiepileptic drug therapy Two or more seizuresSingle seizure secondary to identified CNS lesion with an epileptogenic focusConsider if significant occupational risk if patient suffers a second event.Consider if single seizure event with one or more risk factors for recurrent seizuresConsider in the elderly patient with increased risk of seizure related morbidity (age, prolonged post-ictal state)
19Risk of seizure recurrence in a patient with an apparently unprovoked or idiopathic seizure 31 to 71% risk in the first 12 months after the initial seizure.Risk factors associated with recurrent seizures include the following:(1) evidence of a structural lesion(2) EEG abnormalities(3) partial type seizure(4) family history of seizures(5) focal abnormalities on examMost patients with one or more of these risk factors should be treated
21Principles of Treatment Start with an average dose of a first line drugPoor control? Address compliance, maximize drug dose, confirm right diagnosis (partial complex v.s generalized)Majority of patients are controlled with single antiepileptic drug.This drug can be gradually withdrawn if seizure free for two years.Seizures recur in 25% of patients without risk factors and 50% of patients without risk factors.The drug can be reduced by 25% every two to four weeks.
22Principles of Treatment 20-35% of patients with epilepsy have persistent seizures despite medical therapy.If poor control with maximal dose, monotherapy with second drug.Continue to administer first drug until a full dose of second drug reached, then gradually withdraw first drug.If monotherapy with two drugs fail, patient may need re-evaluation (repeat MRI/EEG) before polytherapy commenced (1998 guidelines).
23Side effects Idiosyncratic toxicity: rash, bone marrow suppression, or hepatotoxicity.Require laboratory tests (e.g., complete blood count and liver function tests)baselineduring initial dosing and titration
24Other management issues: Impact on independence, self-esteem, employment.Driving regulations:Private drivers cannot drive for 3 months after a single seizure.Private drivers can resume driving after being seizure free for 12 months on medication.
26Neurologic Consultation (NEJM 2001) Change in the type of seizureUncertain diagnosis (e.g. normal EEG)Lack of seizure control in 3 monthsFailure of two monotherapiesPatient is considering pregnancyProlonged post-ictal stateHistory of status epilepticus
27SummaryManagement after 1st seizure involves lots of discussion with patient about risks/benefitsRemember impact on driving: tell the ministry!When in doubt about management (especially medications), get a neurologist involved