Chapter 18 - Seizures

Question 1

Describe the pathophysiology of seizures:

Answer 1

Seizures are a pathological excess of neuronal activity that disrupt normal cortical or deep limbic systemic functioning

Question 2

What are the 6 factors that define an ictal event?

Answer 2

1. abrupt onset
2. brief duration (20-30 sec)
3. LOC
4. purposeless activity
5. unprovoked
6. post-ictal state

Note: tongue bitting and incontinence not sensitive

Question 3

Define status epilepticus

Answer 3

New definition: 5 or more minutes of persistent seizures OR a series of recurrent seizures without return of FULL consciousness in between (i.e. still post-ictal)

Question 4

Doses of medications for status epilepticus

Answer 4

1) First line 
BZ's
a) lorazepam: 0.1mg/kg IV
-preferred IV agent 
-give 2 full doses of 4 mg 5 min apart before moving on to second line agents 
b) midazolam -0.2mg/kg/IV IM or IN 
-preferred IM or buccal 
-give 2 full doses of 10mg q5 min before moving on 
c) diazepam 0.15mg/kg IV
- can also be given rectally 

Second line:

1) Phenytoin -20mg/kg IV infusion
- over 10 min
2) phenobarbital
3) valproic acid

Question 5

List 10 differential diagnoses for seizures

Answer 5

1) Drugs of abuse (intoxication or withdrawal)
- ETOH
- stimulants
- LSD, PCP, NMDA
- Herbal products

2) Medications
- antibiotics
- antiarrhythmic agents
- pain medications
- antidepressants
- antipsychotics

3) Metabolic
- hypo or hyperglycemia
- hyponatr or hypernatrem
- hypoxia
- hypocalcemia
- hypomagnesemia

4) Infectious
- Meningitis
- cerebritis
- encephalitis
- cerebral abscess
- non-CNS infections

5) Structural lesions
- tumour
- intracranial hemorrhage
- subarachnoid hemorrhage
- ischemic CVA

5) Systemic
- eclampsia
- extreme fever
- thyrotoxicosis

Question 6

Whats the treatment for refractory status epilepticus:

Answer 6

1) BZ x2 (midazolam/BZ)
2) second line agent (propofol)
3) third line agent (isoflurane anesthesia)

4) non-depolarizing neuromuscular blockade
5) continuous EEG monitoring

Question 7

List 10 indications for head CT in new onset seizure?

Answer 7

1) First seizure
2) Acute intracranial process suspected
3) history of acute head trauma
4) history of malignancy
5) Immunocompromised status
6) Fever
7) Persistent headache
8) History of anticoagulation
9) New focal neurological examination
10) age older than 40 years without epilepsy history
11) focal onset before generalization
12) persistently altered mental status

Question 8

What is the treatment for hypoglycemia caused seizures?

Answer 8

1) D50W in adults >2 years old

2) D10-25W for kids <2 yrs old. Rule of 50s i.e. D10W at 5cc/kg/hr or D25W at 2cc/kg/hr

Question 9

What is the treatment for isoniazid overdose caused seizures?

Answer 9

-pyridoxine 0.5 g/min IV until seizure stops (max dose 70 mg/kg or 5 g)

Question 10

What is the treatment for eclampsia caused seizures?

Answer 10

• seizing woman of childbearing age
• GA 20 weeks up to 6 weeks post-partum
• Treat: Magnesium 6g IV over 15 min

Question 11

What is the treatment for water intoxication/hyponatremia caused seizures?

Answer 11

children, psych patients, athletes

1) Treat with hypertonic saline
- 3% 4-6ml/kg over 1 hour
- 5% hypertonic 50CC

Question 12

What are the most common causes of status epilepticus?

Answer 12

1) antiepileptic drug associated - withdrawal or under dose
2) ETOH related
3) drug toxicity
4) post-stroke
5) CVA
6) metabolic/lytes
7) hypoxia