Ch. 21 - Epilepsy Flashcards

1
Q

Definition of epilepsy

A

Tendency to have recurrent seizures; transient derangement of nervous system 2/2 sudden, excessive, and disorderly discharge of cerebral neurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the 3 major seizure types?

A

Generalized

Partial

Unclassifiable

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Describe the electrical discharges in generalized seizures

A

Bilateral, synchronous and symmetrical, involving BOTH cerebral hemispheres

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Describe a tonic-clonic (grand mal) seizure

A

Tonic phase 10-15 sec (LOC, body stiffens, clench teeth, bite tongue, apnea, urinary incontinence)

Clonic phase 1-2 min (rhythmic muscle contractions)

Postictal phase (confusion and drowsiness)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the common types of generalized seizures?

A

Tonic-clonic (grand mal), absence (petit mal), myoclonic, tonic, atonic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the types of partial (focal) seizures?

A

Simple partial, complex partial

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Describe an absence (petit mal) seizure

A

Brief LOC 5-10 sec with starring or blinking but only minimal motor involvement; consciousness regained with amnesia of event

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

EEG appearance of absence seizure

A

Bilateral synchronous 3-Hz spike and wave activity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What can provoke an absence seizure or its EEG abnormality?

A

Hyperventilation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Describe a myoclonic seizure

A

Brief, usually single, jerking of trunk +/- limbs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

EEG appearance of myoclonic seizure

A

Bilateral synchronized spike and wave activity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What differentiates partial from generalized seizures?

A

Electrical activity of partial seizures starts in defined focus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Define simple partial vs. complex partial seizures

A

Simple partial - w/o impairment of consciousness

Complex partial - with impairment of consciousness

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Where do most complex partial seizures arise from?

A

Temporal lobe (often begin with an aura - taste, smell, deja vu, fear)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are automatisms?

A

Lip smacking, chewing movements, repetitive swallowing, upper limb movements

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What happens when electrical discharge of a partial seizure generalizes?

A

Can have secondarily generalized tonic-clonic seizure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are the 3 types of post-traumatic seizures?

A

Immediate, early, and late epilepsy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Describe immediate post-traumatic epilepsy

A

Occurs at the time of, or within minutes, of head injury; usually does not recur; good prognosis; does not predispose to late post-traumatic epilepsy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Describe early post-traumatic epilepsy

A

Occurs within 1 week of head injury; complicates injuries (e.g. intracranial hemorrhage, prolonged amnesia); predisposes to late post-traumatic seizures

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Describe late post-traumatic epilepsy

A

Occurs after 1 week following head trauma (can be years later)

21
Q

Factors predisposing to late post-traumatic epilepsy

A

Post-traumatic amnesia >24 hrs, intracranial hemorrhage, early seizures, depressed skull fracture

22
Q

Tx of post-traumatic epilepsy

A

Phenytoin or carbamazepine

23
Q

What is the incidence of seizures following craniotomy?

A

18%

24
Q

What is the drug of choice for postoperative seizure prophylaxis?

A

Phenytoin for 6 months

25
Q

What is the relationship between the grade of malignancy of a glioma and the seizure risk?

A

Inverse! Lower grade a/w higher risk of seizure

26
Q

DDx for seizures

A

Syncope (emotional, cardiac, postural, vasovagal), migraine (aura vs. partial seizure), pseudoseizures, movement disorders (Tourette’s vs. myoclonic seizure)

27
Q

What hormone is often elevated after seizures?

A

Prolactin

28
Q

What is the chance of recurrence in a patient with first seizure?

A

78% in 3 years

29
Q

Should you start an antiepileptic after 1st seizure?

A

Controversial; randomized studies say yes (esp. if structural lesion and early life onset)

30
Q

AED after head injuries?

A

Decreases risk of early seizures (first 7 days) but not thereafter

Use phenytoin or carbamazepine

31
Q

AED after craniotomy?

A

Not shown to make a difference but we use them anyway

32
Q

AED ppx after febrile seizure?

A

Not shown to make a difference

33
Q

AED in patients with glioma?

A

Use valproate (1st line); levetiracetam if not controlled

34
Q

AEDs in pregnancy?

A

Increase risk of fetal abnormalities to 4-8% (vs. 2-3%); risk fo child and mother is greater if mother has uncontrolled seizures

AVOID valproate (neural tube defects)

35
Q

What drugs are used for emergent initial therapy in status epilepticus?

A

Lorazepam IV; can also use midazolam IM or rectal diazepam

36
Q

What therapy is used to maintain control in status epilepticus?

A

IV phenytoin, valproate, or levetiracetam

37
Q

What should you do if seizure don’t stop in status epilepticus?

A

Intubate, continuous EEG monitoring, general anesthesia (often with propofol to burst suppression)

38
Q

Phenytoin

A

For partial and generalized motor seizures

Tox: Steven-Johnson syndrome

Metabolized in liver

Half-life 24 hrs + saturation pharmokinetics (“S” shaped)

CHEAP

39
Q

Carbamazepine

A

2 or 3x daily dosage

Tox: bonw marrow, rash, lower WBC, hyponatremia

Liver metabolism

40
Q

Topiramate

A

2x daily dosing

Tox: major cognitive slowing (esp. speech)

Renal clearance

41
Q

Lamotrigine

A

2x daily dosing

Tox: rash, major drug intercation with valproate (doubles VPA levels)

Liver metabolism

42
Q

Valproate

A

For partial and generalized seizures

Rapid turnover in brain

Tox: weight gain, hair loss, liver, NEURAL TUBE DEFECTS

Liver metabolism

2-3x daily dosing

EXPENSIVE

43
Q

Levetiracetam

A

For partial and generalized seizures

Well-tolerated with few drug interactions (useful in ELDERLY)

Tox: behavioral (hostility, paranoia)

2x daily dosing

Kidney clearance

44
Q

Indications for surgery in epilepsy

A

Seizures persist despite AED therapy

Seizure onset in FOCAL area of brain (and area can be removed with low risk of functional deficit)

45
Q

Outcome after temporal lobe resection for epilepsy

A

75-80% become seizure-free

46
Q

Complications after temporal lobe resection for epilepsy

A

Often unrecognized ‘pie in the sky’ visual defect

Verbal memory deficit after dominant hemisphere resection (‘subtle naming changes’)

47
Q

Other surgical therapies available for epilepsy

A

Vagal nerve stimulator, deep brain stimulation (anterior thalamic nuclei), gamma knife radiosurgery

48
Q

What is medical tx of choice for absence seizures?

A

Ethosuximide