Epilepsy and Loss of Consciousness

Question 1

Describe the classical features of a generalised seizure?

Answer 1

May be tonic (increased tone), clonic (involuntary jerks), tonic clonic, myoclonic or absent.

It is associated with impairment of consciousness and distortion of the electrical activity of the whole or a large part of both sides of the brain.

Generalised tonic clonic are the most common in adults, classical features include:

• Loss of consciousness
• Increased muscular tone
• Clonic movements of the arms and legs
• Tongue biting
• Loss of continence

Question 2

Describe the diagnostic criteria of epilepsy?

Answer 2

2 or more unprovoked* seizures.

*no other likely cause

Question 3

Outline the different classifications of epilepsy?

Answer 3

Generalised or Focal

A: Simple focal (no loss of consciousness)
B: Focal dyscognitive seizures
C: Focal seizure evolving to generalised tonic clonic seizures

II: Generalised seizures
A: Absence
B: Myoclonic
C: Clonic
D: Tonic
E: Tonic-clonic
F: Atonic

Question 4

Describe the symptoms of focal seizures arising in different areas of the brain?

Answer 4

Focal (partial):

• Frontal: involves the motor or premotor cortex and leads to clonic movements which may become full tonic-clonic or tonic seizures. (Jacksonian march)
• Temporal: Auditory, olfactory or gustatory aura. Automatisations such as lip-smacking and pulling at clothing are seen along with déjà-vu.
• Occipital: causes visual distortion. (+ve or -ve phenomenon)
• Parietal: causes contralateral dysaesthesias (altered sensation) or distorted body image

Question 5

Which medication should be given for tonic clonic seizures?

Answer 5

1st line: Sodium Valporate

2nd line: Lamotrigine (safest in preganancy)

Can use both together. Other adjuvants are available.

Question 6

Which medication should be given in absence seizures?

Answer 6

1st line: Ethosuximide or Sodium Valporate

2nd line: Lamotrigine

Question 7

Which medication should be given in myoclonic seizures?

Answer 7

1st line: Sodium Valporate

2nd line: Levetiracetam

Question 8

Which medication should be given in tonic or atonic seizures?

Answer 8

1st line: Sodium Valporate

Adjuvant: Lamotrigine

Question 9

Describe the management of status epilepticus?

Answer 9

Status epilepticus a tonic clonic seizure lasting greater than 5 mins

0-5 mins: time the seizure. Remove any objects which may be a danger to the patient. Attempt to take BM and correct it if abnormal.

5-10 mins: benzodiazepine: buccal/IM midazolam OR IV lorazepam/diazepam

10-15 mins: second dose of a benzodiazepine: IV lorazepam or diazepam. Prepare for phenytoin infusion.

20 mins: Give phenytoin infusion over 20 mins. If phenytoin is not available give valporic acid or levetiracetam also 1st line. Contact and anaethetist.

40 mins: Intubate patient giving anaesthetic medication (propofol/thiopental/midazolam/pentobarbitol) + continuous EEG monitoring.

After a period of status epilepticus it is important to monitor myoglobin levels and CK as can cause myoglobin induced renal failure.

Question 10

Describe the potential differential diagnoses of epilepsy?

Answer 10

• Seizures due to focal neurology.
• Syncope
• TIA
• Non epileptic seizures (includes physiological causes as well as psychogenic causes formerly known as pseudoseizures)

Question 11

Describe the driving laws with relation to seizures and epilepsy?

Answer 11

Any person that has an unprovoked seizure must inform the DVLA and surrender their license.

To meet the driving requirements for a group 1 driving license (normal license) a person must be seizure free for 12months with or without medication.

To meet the driving requirements for a group 2 driving license (large goods vehicles including mini buses) a person must be seizure free for 10 years WITHOUT medication.

Question 12

Define syncope?

Answer 12

A transient loss of consciousness with a loss of postural tone usually lasting less than 5 mins, caused by transient cerebral hypoperfusion.

Question 13

What are the different types of syncope?

Answer 13

Neuromediated (increased vagal tone)

• Vasovagal
• Situational (emotion/pain)
• Carotid sinus hypersensitivity

Cardiac: (reduced output)

• Structural (AS, HOCM aka hypertrophic cardiomyopathy)
• Arrhythmia (Long QT, bradycardia, WPW, ARVD, brugada syndrome)

Orthostatic hypotension (postural)

• Autonomic failure (diabetes/parkinsons/age)
• Medication induced (antihypertensives)
• Hypovolaemia

*Arrythmogenic Right Ventricular Dysplasia

Question 14

Describe clinical features which distinguish seizures and syncope?

Answer 14

Seizures:
Before: May have an aura
During: Tongue biting, loss of continence, tonic and clonic or other forms etc
After: Post ictal phase for greater than 10mins

Syncope:
Before: may feel faint
During: May lose continence, may have some minor jerks but less pronounced
After: Usually rapid recovery no post ictal phase

Question 15

Which features in a syncope history will suggest a cardiac cause?

Answer 15

Palpitations preceding the event.

Sudden onset, short duration. May occur whilst seated/lying down, or on exertion.

PMH: heart conditions.
FH: heart arrhythmias or sudden death.

Question 16

Describe how you would initially investigate syncope?

Answer 16

Collateral history.

Observations including lying standing BP (a drop of 20mmhg being significant). Get patient to lie down for 5 minutes then get them to stand up and measure BP after one minute

ECG: Tachycardia/bradycardia, QT prolongation, WFW, brugada syndrome)

BM

Bloods:
FBC (anaemia)

Question 17

What secondary testing can be done in syncope?

Answer 17

Ambulatory ECG/24hr

Exercise testing

Tilt testing (patient lies flat on a table which gradually tilts to standing whilst attached to an ECG)