Post traumatic epilepsy: a question and an answer

One of the readers of my blog asked me a question regarding her son. I am reproducing her question here. My answer to it follows.

V

my son was involved in a car crash 3 years ago aged 17 years and required brain surgery to remove a bloodclot. He recovered well with no ill effects. He had his first fit in November 2009. He had another 2 that same month. CT and MRI scans clear but eeg showed slight abnomal waves over area of surgery. Neuroligist said our choice if wanted to be on medication. Last fit was 27th November 2009 but he has just had another on 8th February whilst flying to holiday Do you thnk meds should be started to prevent further fits.

Dear V,

                    thank you for writing in to me. Your son’s condition is consistent with what is called post traumatic epilepsy. Let me attempt to explain this a little further. Your son obviously was not born with a seizure disorder (epilepsy). He was apparently well till he was involved in a motor vehicle accident (MVA). As a result of the MVA, he suffered head injury and from what you decribe an intracranial hematoma (blood clot) which required evacuation (removal of the blood clot surgically). He had an uneventful recovery but soon there-after had his first convulsion (you do not mention the time interval between the head trauma and the first convulsion).

As the name suggests post traumatic epilepsy refers to epilepsy/ seizure disorder which occurs after head trauma. Usually for post traumatic epilepsy to occur, the head trauma has to be significant such as a motor vehicle accident with significant intracranial hemorrhage or head injuries sustained in the battle field. Many of our soldiers returning from the battlefields of Afghanistan and Iraq suffer bullet shot injuries to the head (these as you can imagine are penetrating head injuries and cause significant brain damage as the high velocity bullet traverses through the skull). IED (improvised explosive devices) related blast injuries cause closed but still significant head trauma and are the signature injury of these two wars. Many of these brave men and women later develop post traumatic seizure disorder/ epilepsy. In other words minor bumps to the head (example you walk into a door) do not cause post-traumatic epilepsy.

There are three types of post traumatic epilepsy. Immediate, early and delayed. Let me explain this at length. Let us assume you are involved in an accident. Your head strikes the ground or steering wheel hard. You have a seizure soon after the impact. This is called immediate or impact seizure. This type of seizure does not lead to seizures later in life and hence such a patient does not warrant to be on long term anti-convulsant therapy.

Early post traumatic seizures are those which occur within 6 months of injury while late post traumatic seizures are those which occur after 6 months. Remember you can have your first post traumatic seizure as long as 5 years after the head injury. In other words if 18 months go by and the person has not had a seizure then likely he shall not have seizures as a result of head trauma. Patients who have early and late post traumatic epilepsy may warrant treatment with anti-convulsants. This is because the brain has suffered a scar (as a result of the head injury) and it is this scar tissue (consisting of damaged brain tissue) which then misfires and acts as a seizure focus (point in the brain where the seizure originates from).

In the case of your son, since he has suffered multiple convulsions since his head injury, he likely needs to be on an anti-convulsant. This decision though shall be made by his neurologist after consideration of factors which I mentioned earlier in my post. EEG may or may not be helpful in this regard (a normal EEG does not rule out seizure disorder and vice versa not every patient with a seizure disorder has an abnormal EEG).

I hope this is helpful to you. I wish him my very best.

Personal Regards,

Nitin Sethi, MD

Seizures, convulsion, fit, epilepsy

 

 

 

  • Seizures/ Convulsions/ Fits/ Epilepsy

      

    Let us now talk a little about seizures. Seizures are among the most common neurological conditions encountered by physicians.  What is a seizure? Simply put it is a short-circuit of your brain. Brain cells also called neurons communicate with each other via electrical charges.  This communication process is highly organized and smooth most of the times. Rarely for various reasons ,which I shall elaborate later on in the article, things go awry and the result is a seizure ( lots of brain cells firing at the same time in a disorganized manner). So seizure is nothing but a hypersynchronous discharge of brain cells.

    Is there any difference between a seizure and a convulsion?  Well the answer is yes and no. The terms can be used interchangeably and essentially  mean the same thing. But usually as neurologists when we use the term convulsion we mean the patient was “shaking” visibly. The type of seizure you see in a movie–lot of thrashing around, person losing consciousness, falling down, drooling, biting his tongue or lips, losing control of his bladder ( many people may pee on themselves during a big convulsion) and then is confused and disoriented as help arrives. Pretty dramatic, you cannot miss it. You see someone doing that and you know he is having a convulsion and you call for help.

    Seizures though can be very subtle, so subtle that even an attentive and doting parent might miss it.  Short arrest of behavior ( staring spells), losing train of thought in the middle of a sentence, sudden speech arrest, short rapid jerks of the arms and legs on waking up in the morning, a strange smell ( the classical smell described is that of burning rubber), abnormal behavior at night while sleeping: these may all represent seizures.

    It is important to recognize these myriad manifestations of seizures. Sometimes these may be missed and people continue to suffer from seizures for years.

    So that brings me to the next point I want to discuss with you. HOW DO WE DIAGNOSE SEIZURES??  Easy, most of the time it is by a good history. A thorough history taken by a physician ( need not be a neurologist or an epileptologist) can usually give the physician a pretty good idea if you indeed did have a seizure. So when asked try to give as thorough a history as possible: how did the episode start? what were you doing at that time? did it occur during sleep? did you smell something strange? did you lose consciousness and completely black out or were you just confused and disoriented? could you understand people around you at that time? did you shake? if yes did the whole body shake or one side shook? did you bit your tongue or pee on yourself? were you confused after the episode and if yes how long did it take for you to come back to normal?

    As you can see lots and lots of questions. Sometimes you may not know the answer to all of them by yourself ( you were passed out, how can you know!!!!) well in that case we try to get information from family and friends, a bystander who saw the episode, the emergency medical service people who were called to help you.

    Once your physician feels that you may have had a seizure, then come the questions:

    1) Why did you have a seizure and what was the cause of the seizure.

    2) what kind of seizure was it ?( I shall come to this later)

    3) was the seizure a one time event or can it occur again?

    4) Does it need to be treated?

    5) if it warrants treatment what medication is required?

    6) will the medication ensure that you do not have a seizure again?

    7) how long do you need to take this medication?

    8) can you drive? does the seizure place any restriction on your lifestyle?

    9) if the medication does not work: what do you do then?

    I shall tackle these questions one by one. Enough information for now, I need a break!!!

    Personal Regards,

    Dr. S

      

    Seizures/ convulsions/fits/Epilepsy

      

    So we take off from where we left and discuss about the different types of seizures. Broadly there are two types of seizures: generalized and partial.

     

    1) Generalized seizures as the name suggests come from the whole brain, that is the whole brain malfunctions and misfires. As the whole brain is malfunctioning it is but natural that the person shall lose consciousness and is amnestic for the event and for some period of time afterwards. These are the classical big seizures you see in movies with the falling, frailing arms and legs and tongue biting. What many people do not know is that generalized seizures can be more subtle: staring spells seen in children are a type of generalized seizures called Absence Seizures.

     

    2) Partial seizures or focal seizures as the name suggests come from one part of the brain i.e. only a part of the brain has the seizure. As a result consciousness is usually retained albeit it may be impaired. The patient may have his or her eyes open and one part of his body the arm or leg may be shaking but he is not able to respond adequately if you call out to him. Focal seizures are further subdivided depending upon whether the manifestations are primarily motor, sensory, autonomic or psychic.

     

    3) Partial seizure with secondary generalization: the name is self explainatory. The seizure starts off from a focal area in the brain and then spreads and soon the whole brain is involved. Most of the seizures are partial with secondary generalization but patients and even attentive bystanders might not volunteer the history that initial symptoms were focal. It is very important you tell your doctor exactly what happened right at seizure onset: did you smell something strange? did you have a funny taste in your mouth or a strange sensation in your belly? did one part of the body shake first and then the seizure spread to other body parts.  The strange feelings noted at seizure onset are called auras and they help us in localizing where in your brain did the seizure come from. It is very very important that you give a good history about this because the medications used to treat generalized seizures are at times different from the ones effective against partial seizures. I shall come back to the medications at a later date.

     

    Numerous other types of seizures have been described especially in children and there quite a few epileptic syndromes seen in the pediatric age-groups. I shall comment on these briefly as we go along.

    Enough typing for now. Its freezing outside here in New York City and I think I need a cup of coffee to jump start my brain.

     

    Dr. S

     

    Seizures/ Convulsions/ Fits/Epilepsy

    Now that we know a little something about seizures in general, lets turn to managment of seizures and epilepsy. As a work-up of why one had a seizure and to determine its cause, your physician may order a few tests. The mostly commonly ordered tests include something called an electroencephalogram or EEG in short and an imaging test of the brain either a CT scan also called a CAT scan or more commonly a MRI scan (MRI stands for magnetic resonance imaging).

    Let us talk a little about these tests. An EEG is actually very similar to an EKG (electrocardiogram). Basically electrodes are placed on the surface of your head (completely painless procedure) and then one looks at the brain waves for about 30 mins and tries to find out if and where does the brain misfire. An imaging study like a CT scan or MRI scan is done to rule out the presence of anything structural inside the brain that might be the cause of the seizure like a brain tumor or a vascular anomaly. It is important to rule out a structural cause for a seizure as its presence guides the managment.

    You have something inside the brain which does not belong there, you may need a neurosurgical opinion to get it out. Most of the times in people who have epilepsy no structural cause is found on neuroimaging and then the treatment turns to how to manage/control/prevent further seizures. It is thought in these patients the problem is at the cellular level, something which we cannot see on imaging studies. If there is nothing to be seen, there is nothing to be taken out.

    Let me lay down some basic tenents of treatment:

    1. A single provoked seizure may not warrant treatment. What does that mean? Well basically if you had a seizure which was  because of something you did like used a drug of abuse (cocaine etc), alcohol  in excess ( a drinking binge with the buddies may cause what we doctors call “rum fit”), did not sleep for a couple of nights, some antibiotics and anti-depressants have been known to cause a seizure: then you may not need to be treated. Just do not abuse the drug again and you shall be fine. No more seizures no need to be on long term anti-seizure medications.

    2. A single unprovoked seizure may not warrant treatment. Sometimes a person may have a single seizure for which no provoking cause can be found inspite of a thorough search for one. Your EEG and scan is normal.Your doctor may decide just to observe you and not start any drug treatment. Why you may ask we do this? Well the reason is simple. Studies have shown that as many as 70% of single unprovoked seizures may not recur ever. So why treat someone with anti-seizure medications with their risk of side-effects. It is better at times to just watch. If seizures recur your doctor at that time might decide to treat you.

     

    We shall stop now, the sun is out, central park is calling, I am going to head out for a run.

     

    Personal Regards,

    Dr. S

     

    Seizures/fits/convulsions/ epilepsy

     Management/ treatment of seizures: let us now turn to the treatment of seizures. I shall discuss this broadly under two headings:

    1) acute management of seizures: what do you do and what happens in the hospital setting if one has a seizure?

    2) management of seizures over the longer term or rather I should say ongoing treatment of someone who has epilepsy.

     

    Let us start with acute management of seizures. Some of us have seen people around us have a seizure either at home, outside or in the workplace. What do you do? Whom do you call? Is the person who is having a seizure going to die if we do not do something? Crude as it may sound here, the seizure itself never kills a patient it is the circumstances surrounding the seizure which may prove lethal. Let me explain further. Most of the seizures stop by themselves in a few minutes (though it may seem hours to the person witnessing the seizure). More often than not, the seizure has already stopped by the time  EMS (emergency medical services) arrive on the scene. The patient has stopped shaking and is just confused or may have even fallen asleep. So more often than not there is no active intervention needed on the part of the EMS. All they may do is check the patient’s vitals, maybe give him some supplemental oxygen and then transport him to the nearest hospital for further evaluation. There that was simple wasn’t it? However let me paint another scenario. Person is standing by the side of the subway track waiting for the train. Has a seizure and falls onto the tracks. Cracks his skull open, may get run over by the train if not pulled out by someone. There-in lies the problem with seizures and epilepsy and which patients find the most unsettling. The uncertainity, the possibility of having a seizure at the wrong place and at the wrong time. Deaths have occurred when people have had a seizure while driving, swimming or even while taking a bath in the tub.

     

    So if you see someone having a seizure, do not panic and follow some simple guidelines. I shall list them out for you.

    1. Do not try to physically restrain the patient. You try to hold down his arms or legs you may cause more harm than good like a dislocated shoulder.

    2. Just try to ensure that the patient is not hurting himself: like if he is hitting his head on the hard floor while having a seizure you may try to gently hold his head or put a cushion under it.

    3. Remove anything from the surroundings which has the potential for causing injury: things like a hot stove, sharps,

    4. Do not put anything like a spoon or your finger into the patient’s mouth to prevent it from shaking. The patient may bite your finger off or may choke.

    5. If possible gently turn the patient’s head to the side, this causes the tongue to fall away opening the airway and lets the oral secretions (saliva) drip out from the side of the mouth and prevents aspiration.

    6. I have encountered people with certain misconceptions like having the patient smell something pungent (smelling salts, a stinking shoe) aborts the seizure. These things do not work, you are wasting your time and not helping the patient.

    7. Once you have made certain the patient is safe, better to utilize the time to call EMS. Tell them clearly what you saw and did. Give a good history. Usually once the seizure stops the patient is not immediately responsive, you may hear sonorous respirations as if he is in a deep sleep.

    Time for a break!!! This took longer than I thought.

    Dr. S

    So lets pick up from where we left off a couple of days ago. Lets talk about the acute managment of a seizure in the hospital setting. A person is brought to the hospital by the EMS and is still having a convulsion as he is wheeled into the ER. We call this Status Epilepticus ( a potentially life threatening condition when a patient has been having a seizure for greater than 30 mins or has had multiple seizures in near about the same amount of time without regaining consciousness inbetween).

    There are a couple of things which doctors do in this setting. I shall list them out.

    1) Protect the airway, check the vitals, maintain the circulation and oxygenation/breathing (ABC). We make sure that the patient is breathing and oxygenating well ( no obstruction to his airways), sometimes when the patient is not breathing well on his own, the doctors might put a tube down the throat into the trachea and put the patient on a ventilator ( a machine which does the work of breathing for the patient until he/she can breathe on his own). If the blood pressure is low, intravenous fluids may be administered.

    2) A quick search is made for the cause/etiology of seizures. Blood is checked for the blood sugar level, electrolytes ( sodium, calcium, magnesium etc). One of the common causes of seizures especially in people with diabetes is low blood sugar. Either the patient takes too much of his diabetic pills/ insulin or the patient may have missed a meal letting his blood sugar fall to a dangerously low level.

    In such a case intravenous dextrose ( a form of sugar) stops the seizure immediately.

    3) To stop the seizure acutely certain medications may be administered. These commonly belong to the benzodiazepines group of medications with names like Diazepam (valium) or Lorazepam (ativan) followed by a longer acting anti-seizure medication like Dilantin (phenytoin).

    4) Once the seizure stops the work-up begins to find the etiology of the seizure ( remember the MRI and EEG I talked about before).

     

    Depending upon the cause of the seizure, its risk of recurrence, the type of seizure ( partial Vs generalized), the doctor may prescribe an anti-seizure medication ( we call them anti-epileptic drugs or AEDs).  There are many different AEDs in the market. Each drug has its own mechanism of action, the kind of seizures it is most effective in controlling, side-effect profile and recommended dosage for seizure control.

     

    Your doctor shall discuss this with you in detail. Please remember a number of AEDs can potentially interact with other medications which you may be taking for blood pressure etc. So remember to tell your doctor a complete list of your medications. Also some AEDs lower the efficacy of birth control pills, thus women with epilepsy may be advised to use alternate methods of contraception.

    An important point here especially for pregnant women with epilepsy. Some AEDs have been linked to cause major congenital malformations in babies like cleft lip, cleft palate and spinal column deformities (spina bifida). Pregnant women with epilepsy remain a high risk group-they need close supervision by a doctor well versed with the use of AEDs during pregnancy. Some AEDs are best avoided in pregnancy while others have a relatively safer track record when it comes to the incidence of major congenital malformations.

    I hope this small discourse on seizure is informative. I shall tackle brain tumors next.

    Personal Regards,

    Dr. S

      

Questions about epilepsy?

Ask Dr S:

neurologistnyc@yahoo.com

 

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