Neurology: Seizures

Broad Categories

The following broad classifications and subsequent subclassifications of seizures used in this document are consistent with medical literature and international professional society classification schemes current as of mid-
2014.1 (See Appendix A for definition and classification of seizure disorders.)

Provoked Seizures
Provoked seizures are ones for which a transient precipitating factor can be identified and removed.

Provoked Seizures with Low Risk of Recurrence

For the following situations, once the underlying cause has resolved and/or is being appropriately treated, restriction as related solely to the seizure is not recommended. The underlying cause needs to be evaluated regarding possible effect on safe and effective essential task performance. Additionally, the nature of the underlying cause for the seizure should be assessed for possible re-occurrence while performing job functions as this may necessitate restriction of job activities. If the treating physician prescribes anti-epileptic drugs, the LEO should be evaluated according to Provoked Seizure with High Risk of Recurrence (see below).

Examples of provoked seizures with a low risk of recurrence include:

• Medication-associated
• Transient toxin-exposure-associated
• Transient metabolic abnormality-associated
• Eclampsia-associated
• Drug or alcohol withdrawal-associated
• Immediately at the time of or less than seven (7) days following head trauma with no intracranial hemorrhage

Provoked Seizures with High Risk of Recurrence
Persons who have had a single seizure “provoked by” one of the following conditions have a risk of recurrent seizure equivalent to that found for persons with epilepsy.1 Thus, they should be assessed by the same guidelines as persons with a formal diagnosis of epilepsy.

Examples of provoked seizures with a high risk of recurrence include those occurring in the context of:

• More than seven (7) days following head trauma2
• Intracerebral or intracranial hemorrhage
• Brain infection – encephalitis, bacterial meningitis, abscess, cysticercosis
• Stroke – ischemic or hemorrhagic
• Brain surgery
• Structural brain lesion such as brain tumor
• Occurrence during an active phase of an autoimmune disease

Single Unprovoked Seizure
Unprovoked seizures are defined as having no identifiable precipitant following evaluation including lab studies, brain MRI, EEG, and evaluation by a neurologist with expertise in seizure evaluation and management.

Normal EEG, Labs, and Brain MRI
Persons who have been seizure-free for 5 years on or off anti-epileptic drugs approach the risk of seizure for persons who have never had a seizure. Persons with single unprovoked seizure may be able to safely and effectively perform essential LEO job functions if they having been seizure-free for the most recent consecutive 5 years.

Abnormal EEG and/or Brain MRI
Persons who have had an unprovoked seizure and an abnormal EEG (consistent with an eliptogenic pattern) or abnormal brain MRI should be considered as having epilepsy (see below).

Epilepsy
Epilepsy is defined as a “disease of the brain”1 (see also Appendix A) and is characterized by any of the following:

• Two or more unprovoked seizures more than 24 hours apart; OR
• One unprovoked seizure and a probability of further seizures similar to the general recurrence risk (at least 60%) after two unprovoked seizures, occurring over the next 10 years; OR
• Diagnosis of epilepsy syndrome.

Controlled Epilepsy
Persons with epilepsy may be able to safely and effectively perform essential LEO job functions if they:

• have been seizure-free for the most recent consecutive 10 years; AND
• take an ongoing regimen of seizure medications; AND
• are not having any side effects from the anticonvulsant medication that would adversely affect safe and effective performance of essential LEO job functions as noted in the Medications chapter. (Note: A neuropsychology assessment may be used to evaluate any cognitive impairment caused by the medications or associated with the seizure disorder.3,4,5,6)

Resolved Epilepsy
A person’s epilepsy is considered resolved1 if they:

• are past the applicable age of an age-dependent epilepsy syndrome; OR
• have not had a seizure for the most recent 10 consecutive years; AND
• are not taking any seizure medications for at least the most recent 5 consecutive years.

Seizures Associated with Withdrawal of Anti-Epileptic Drugs in Persons with a Diagnosis of Epilepsy
Persons who have stopped anti-epileptic drugs (AEDs) either under medical management or on their own and have a recurrent seizure prompting recommencing medications may be able to safely and effectively perform essential LEO job functions if they either:

1) have been seizure-free for the most recent consecutive 10 years; AND

• are taking an on-going regimen of seizure medications; AND
• are not having any side effects from the anticonvulsant medication that would adversely affect safe and effective performance of essential LEO job functions as noted in the Medications chapter;
  OR

2) have not had a seizure for the most recent 10 consecutive years; AND

• are not taking any seizure medications for at least the most recent 5 consecutive years.7,8

Seizures in Association with Surgical Treatment Epilepsy
Although many people who have undergone surgical treatment for refractory temporal lobe epilepsy achieve high rates of seizure freedom, the risk of recurrent seizures is high with or without anticonvulsant therapy. Persons who had surgical treatment for epilepsy may be able to safely and effectively perform essential LEO job functions if they either:

1) have been seizure-free for the most recent consecutive 10 years following surgery; AND

• are taking an on-going regimen of seizure medications; AND
• are not having any side effects from the anticonvulsant medication that would adversely affect safe and effective performance of essential LEO job functions as noted in the Medications chapter;
  OR

2) have not had a seizure for the most recent 10 consecutive years following surgery; AND

• are not taking any seizure medications for at least the most recent 5 consecutive years.9,10