This patient had febrile seizures as a child but experienced no further events until the recent episode on an airplane. How would you proceed?
EPILEPSY CASE OF THE MONTH
A 21-year-old man sees a neurologist after having a seizure on an airplane 1 week earlier. He has very little recollection of the episode.
He says that during a 3-hour flight home from college he watched part of a movie, ate a sandwich, and drank a beer. He recalls feeling dizzy and does not remember anything after that until he woke up in a hospital in his hometown. He was given intravenous phenytoin and sent home with a prescription for levetiracetam and a recommendation to see a neurologist.
He was told that he had lost control of his bladder at some point during the episode. His tongue and left shoulder were both sore for several days after the seizure, but he did not have any bruising or swelling.
The patient has not had any further seizures, and he has not filled his prescription for levetiracetam.
Past medical history
According to his parents, the patient had febrile seizures when he was a young child. He was not diagnosed with or treated for epilepsy at that time, and he did not have any seizures after the age of 10. The patient does not recall the seizures he had during childhood.
He has not been a good student but does not have cognitive or physical deficits. He explains that his academic performance is effort related.
The patient says that he drinks at least once or twice per week, typically consuming about 4 or 5 alcoholic beverages on each occasion. He has not had similar reactions to alcohol before. He has used recreational drugs, including marijuana and cocaine, a few times during high school and college. He did not become ill or have any adverse reactions after using drugs.
The patient’s mother has had about 5 seizures throughout her life. She had her first seizure during her early childhood, and she recalls having a few seizures during adolescence and adulthood. She was never treated with anticonvulsants. She does not recall any particular seizure trigger.
The patient’s older sister, aged 27 years, has been diagnosed with epilepsy. She had febrile seizures as a child and continued to have seizures (even afebrile) throughout adolescence and early adulthood. She currently takes an anticonvulsant, but the family does not know the name of the medication.
Physical and neurological examination
The patient is a slim young man in no acute distress. He is alert and oriented, cooperative, and able to give a clinical history. He does not have any involuntary tremors, jerking, or shaking movements during the examination.
The results of the physical and neurological examinations are normal.
A brain CT scan performed in the emergency department was normal. An electroencephalogram (EEG) showed occasional spikes corresponding to the left frontal lobe.
A brain MRI scan revealed a small (2 mm) arteriovenous malformation (AVM) in the right parietal lobe. The patient’s parents were asked whether he had any brain imaging at the time of his childhood seizures. They were unable to track down copies of the films, but an MRI report found in their records at home mentions the small AVM and states that it is not concerning. The patient’s sister and mother do not have any vascular or structural brain abnormalities.
What is your diagnosis-and how will you proceed?
DIAGNOSIS: AVM AND FAMILIAL EPILEPSY
The patient has potential reasons for a predisposition to seizures, including his family history of epilepsy and his history of febrile seizures. His medical team discussed the AVM and opted not to treat it at this time. His EEG abnormalities do not correspond to the AVM, which makes the vascular abnormality less likely to be related to his seizure tendency, although it is almost impossible to know for certain.
The patient does not want to take anticonvulsants because his sister, who regularly takes anti-seizure medication, says that the medication makes her feel foggy. The patient agrees to avoid seizure triggers, including lack of sleep. He also agrees to stop drinking and using recreational drugs.
This patient presents a challenging case. It is not clear what triggered his recent seizure. His infrequent seizures have not motivated him to take medication. And because epilepsy can produce infrequent seizures, it is possible that he may never experience another seizure, even without treatment. In fact, experts agree that infrequent childhood seizures can be untreated.1
The patient has a predisposition to seizures, as evidenced by his childhood febrile events. His lack of seizures throughout adolescence could be a good sign. However, it is not possible to predict whether he will have further seizures. His family history supports the fact that he has congenital epilepsy. Family members who have epilepsy tend to have similar ages of onset, which is true of this patient’s family.2
The patient’s AVM presents a confusing picture, and it should be monitored to see whether any changes occur over the years.
• People with a diagnosis of epilepsy can have infrequent seizures
• Vascular malformations can trigger seizures, but they can be present without causing any neurological deficits
• Family members who have epilepsy can have varied severity of the condition, with different seizure frequencies
1. Arts WF, Geerts AT, Brouwer OF, et al. Childhood epilepsy with a small number of seizures may be left untreated: an international prospective study. Epileptic Disord. 2019;21:141-153. doi: 10.1684/epd.2019.1040.
2. Ellis CA, Churilov L, Epstein MP, et al; Epi4K Consortium. Epilepsy in families: age at onset is a familial trait, independent of syndrome. Ann Neurol. 2019;86:91-98. doi: 10.1002/ana.25499. Epub 2019 May 20.