When a seizure is not a seizure (pseudoseizures)

When a seizure is not a seizure (pseudoseizures)

Nitin K Sethi, MD

Assistant Professor of Neurology

New York-Presbyterian Hospital

Weill Cornell Medical Center

New York, NY 10065

The month of Feb finds me in New Delhi, India. I have been invited to present a talk on psychogenic non-epileptic seizures (PNES). You may now be wondering what does that mean. Well that is what I plan to discuss in this post of mine. Let us look at the term again:

P–stands for psychogenic  meaning the event has a psychological basis to its existence.

NES–stands for non-epileptic seizure meaning the event is not a epileptic seizure.

So let me put it all together in simple language.  Let us assume our character for this short story is Michelle. Now Michelle is a 25-year-old young lady who is married to John. All looks great from outside. Michelle has a good job, a fun life in Manhattan and a good circle of friends. But all is not hunky dory. Michelle and John have been having some problems. John is verbally and lately physically abusive to her. Michelle feels trapped in a loveless marriage but sees no way out.

So one day Michelle and John are at a dinner party.  Seated at their table are few close friends as well as some strangers. As the main course is served, Michelle suddenly leans back, she utters a cry. Then her eyes are noticed to roll up.  John and Michelle’s friends quickly ease her to the ground. She is then noted to have vigorous side to side shaking movements of her head, asynchronous out of phase thrashing movements of her arms and legs. All this time her eyes are open and she is muttering help me, help me.

Michelle is rushed to the hospital where a doctor like me is called to consult on her.  What happened to Michelle?  Seizure or not a seizure, is the question. To help determine the etiology, her doctor orders a video-EEG study.  Michelle is admitted to the hospital and electrodes are pasted on the top of her head to record her brain waves (encephalogram). The encephalogram is time locked to the video camera mounted on the ceiling which records Michelle’s movements. Hence the name VIDEO-EEG.

So imagine Michelle. Sitting in bed, wires attached to her head, surrounded by friends, family and most importantly an extremely concerned John by her bedside. And then it happens again. A dramatic event where she yells a bone chilling cry and then shakes all over.  Now everyone wants to know what is plaguing Michelle.

So what did the video-EEG record?  Was it a seizure or not? Surprisingly when the EEG data is analysed, at the time when Michelle is having her “seizure” the EEG shows no change in the brain waves.  Meaning than Michelle is not having a true seizure, the event is non-epileptic.

Events such as the above are called PNES. They are psychogenic since they have a psychological basis to them. In Michelle’s case they likely reflect her struggles in her marriage and may be a sign for help. Some patients have psychogenic seizures/ pseudoseizures voluntary.  Meaning they might malinger a “seizure” for a secondary gain such as to get social security payments, to escape school and so forth.

PNES  are common and difficult to diagnose and treat.  As you may imagine patients are frequently misdiagnosed. Some are misdiagnosed as true seizures/ epilepsy and started on anti-convulsant drugs which have their own side-effects.  When one drug fails to stop the “seizure”, new drugs are tried.  So frequently these patients are on multiple anti-convulsants and their “seizures” still continue.

PNES do not stop till the underlying psychological issues are tackled. In Michelle’s case simply telling her that she does not have true seizures is not the end of the road. She needs to be referred to a psychiatrist and a therapist. Only then she may be cured.

Persistent vegetative state and minimally conscious state

In this post I thought I would talk a little about persistent vegetative state (PVS) and minimally conscious state (MCS). Though this topic may not concern many of you, I feel it should be discussed as the question of PVS is raised frequently by family members of patients who are in coma.

Doctor is he brain dead? Would he wake up? If yes when? Is he going to be a “vegetable” for the rest of his life?

So what is PVS and how does it differ from brain death. I shall try to make this simple and explain with the aid of a crude example. Let us assume a person suffers major head trauma in a motor vehicle accident. He is brought to the hospital and CT scan shows extensive bleeding in the brain. He is in the intensive care unit on a mechanical ventilator while his blood pressure is been supported with the help of medications (we call such medications vasopressors). Now a neurologist is called to see him regarding prognosis. On examining him the neurologist notices that his pupils are dilated and fixed (do not react to light) and the rest of his brain stem reflexes are also not elicitable (please see my previous post on brain death). An EEG is ordered to confirm the diagnosis of brain death. The EEG shows no cortical (brain) activity above 2 microvolts (meaning it is essentially a flat line) and is thus consistent with electrocerebral inactivity (ECI). SUCH A PERSON IS BRAIN DEAD AND CAN THUS BE REMOVED FROM THE VENTILATOR (OF COURSE WE TAKE THE FAMILY’S WISHES INTO CONSIDERATION). BUT FOR TECHNICAL PURPOSES HE IS DEAD. Remember what I said earlier one cannot die twice, once when the brain stops and once when the heart stops.

Now lets take the second scenario. The neurologist examines the patient and notices that he does not respond to verbal commands, does not respond to a painful stimuli such as a pinch but the brain stem reflexes are intact. His pupils react to light, he gags when the back of his throat is touched, he takes a gasp on his own when he is temporarily disconnected from the ventilator. THE NEUROLOGIST RIGHLY SAYS” PATIENT IS NOT BRAIN DEAD BUT HIS PROGNOSIS FOR RECOVERY IS GUARDED“. Time goes by say about a week. The patient is now still in the intensive care unit but at times responds when he is stimulated, does not open his eyes or talk but moves his arm if he is pinched. More time goes by say about 2 weeks. The patient is now opening his eyes. He now has a tracheostomy and slowly is been weaned off the ventilator. He is still not able to talk and does not interact with any of his nursing staff or his family. More time goes by, the patient has been weaned off the ventilator. He is now out of the intensive care unit and is transferred to the hospital floor. A neurologist’s opinion is asked for as “the patient does not respond”. The neurologist examines the same patient whom he had seen in the aftermath of the trauma. 10 weeks have gone by since the injury. The neurologist finds that the patient open his eyes spontaneously, at times even yawns, he is told by the family at bedside that the patient has sleep wake cycles (meaning he sleeps at night and then wakes up after some time just like any other “normal” person).  As the patient’s mother walks into the patient’s room, the neurologist notices that the patient tracks her with his eyes for a short time when she enters. But there is no meaningful interaction of the patient with his environment. It is as if the patient is there but not there. He does not make purposeful eye-contact with anyone. There is nothing in his actions to suggest that he is truly responding to those around him or interacting with them. The tracking movements of the eyes are semipurposeful and so is the yawning behavior–more like a reflex if not anything else.

A person like the one above may be labelled as one who is heading into the persistent vegetative state (PVS) category. You can imagine the delimma for the family members if you tell them that though the patient may remain “alive” for years, he shall never have any meaningful neurological interaction and hence it is better to let him go. “BUT DOCTOR HE IS ALIVE, HE YAWNED TODAY, HE LOOKED AT ME WHEN I WALKED INTO HIS ROOM”: they will say.

Patients who are truly in the PVS shall never recover any meaningful neurological interaction with the environment–this is by defination. But as is true in medicine, everything is not black and white. there are shades of grey. Patients who meet the criteria for PVS but then who later on start showing “some” recovery. Some purposeful goal directed behavior starts emerging. So a new category of minimally conscious state has not come into the literature. There have been some studies done to show that the brains of these patients do actually respond and they are far from a PVS. A lot of research is now been carried out to determine how we can benefit these patients.

If the right procedure is followed and the neurological examination and relevant investigations are carried out and repeated if required after an interval of time, most of these patients can be rightly categorised into the brain dead, PVS or MCS category thus avoiding confusion and anguish to the family members.

Nitin Sethi, MD

Coma and other altered states of awareness

In this post, I thought i shall talk about coma and other altered states of awareness. What do we mean when we say a patient is in coma? Just what does coma mean?

Coma has been defined differently in different medical and neurology textbooks. In simple terms it means a patient who has decreased conciousness to the extent he is not aware of his surroundings and does not respond when stimulated by the external means even when the stimulus is noxious or painful like a pinch applied to the skin of the nipple. These patients are usually seriously ill and are in the intensive care unit of the hospital. As they are unaware of their external surroundings they need to be supported, meaning that their diet has to be maintained, their fluid status, making sure they are not constipated etc.

There can be numerous causes for coma. some of them are related to the brain itself and some of them are systemic, that is they affect the body.

1) Neurotrauma: head injuries frequently can lead to a coma with loss of consciousness sometimes for prolonged periods of time. Intracranial hemorrhage or bleeding into the brain is one cause of this. This bleeding raises the intracranial pressure and this compresses the brainstem and hence leads to coma.

2) Large stroke: a large stroke can lead to loss of consciousness and coma. Again a large stroke frequently leads to an increase in intracranial pressure and this leads to a depression in the state of awareness and coma.

3) Infections of the brain like meningitis and encephalitis may also lead to a state of coma.

4) Large tumors of the brain can also present with depression in sensorium (decreased consciousness) and coma.

5) Frequent seizures one after the other (this condition is referred to as status epilepticus): patients may be unresponsive even though they are not visibly  “shaking” (that is there are no convulsive movements but patients are unresponsive because their brain is still having seizures).

6) Anoxic hypoxic injuries to the brain: anoxia is lack of blood flow and oxygen to the brain. This kind of coma is frequently irreversible.

7) Systemic causes of coma: metabolic conditions like low sodium (hyponatremia), low blood glucose (hypoglycemia), metabolic acidosis ( as seen in diabetic ketoacidosis), liver dysfunction (cirrhosis), renal dysfunction and renal failure, congestive heart failure, hypercapnia (where there is too much carbon dioxide in the blood) all are common causes of coma.

8) Toxins: ingestion of toxins like drugs of abuse, heavy metals, insecticides, overdose of antidepressants, pain killers, sedatives can all lead to coma.

 

As the causes of coma are protean, when patients present to the hospital in a comatosed state, we do a rapid triage and try to localize the etiology of the coma. Blood is drawn to check for sodium, potassium, liver and renal functions and glucose. If there is some evidence that an infectious etiology is the cause of coma we may draw blood for culture and do a spinal tap to examine the spinal fluid to rule out meningitis. Depending upon the history and examination findings other investigations may be carried out like CT scan brain, MRI brain, Chest X-ray, EEG and so on.

The treatment of “coma” depends upon the cause of coma. Frequently as I stated above these patients need to be admitted to the intensive care unit and need respiratory and circulatory support. Depending upon the cause of the coma, they may or may not need neurosurgical intervention. If there is a big bleed in the brain and the intracranial pressure is too high, the blood may need to be removed (evacuated). These patients may need broad spectrum antibiotic coverage if they have an infection or an antiepileptic drug if they are having seizures. If toxin or drug ingestion is the cause, then we try to remove the toxin or drug from the blood stream with the aid of an antidote.

Nitin Sethi, MD

Absence seizures and staring spells

Let us talk about another kind of childhood seizures called Absence seizures or at times Petit Mal seizures. Childhood absence epilepsy as the name suggests starts off in childhood. The seizures are subtle and thus may escape detection from even doting parents. Most of the time, it is the teachers in school who first report that the child at times is noted to “stare” or “daydream”. At times the school grades start falling and this brings the child to medical attention.

Absence seizures as the name suggests are short duration seizures where-in the child is “absent”. By that I mean that for the short time (few seconds to a minute)  during which the child is having a seizure, he or she is not aware of the immediate surroundings. This is because even though an Absence seizure is brief, it is a generalized seizure (meaning the whole brain has a seizure and thus malfunctions for that few seconds). It is different from a generalized convulsion in that you do not seek the violent shaking movements of the arms and legs. Thus it is subtle and may escape detection in the earlier years.

Absence seizures need to be treated. The reason for this is that the seizures are frequent, at time hundreds in a day and these frequent seizures impair the cognitive development of the child. The diagnosis is relatively straight forward and your physician might make it on the basis of a good history. An electroencephalogram (EEG) study may shown the characteristic EEG pattern of Absence epilepsy confirming the diagnosis. An imaging study is usually not needed unless there are some atypical features in the presentation.

Once the diagnosis is made, Absence seizures can be readily controlled with anti-epileptic drugs. Two drugs are commonly used for this kind of epilepsy: ethosuximide and valproate. Children usually do not need to be on anti-epileptic drugs for prolonged length of time and they usually outgrow these seizures by the time they reach the age of 17.

Dr. Sethi