What disorders may produce manifestations that resemble seizures but are not epileptic?
• Stroke/transient ischemic attacks (TIA): strokes and TIAs happen due to low or no blood flow to the brain which could result in brain cells (neurons) dying. If the stroke is transitory and brief, it could be mistaken for a seizure. As an example, in the case of a patient reporting numbness of the left hand lasting for few minutes, this could possibly be a few things: 1) the manifestation of a transitory ischemic attack (TIA) or 2) a simple partial seizure. In both cases, the same part of the brain is involved (remember that the Parietal lobe controls sensation). In the case of the stroke, there is less blood flow to the parietal lobe. In the case of an epileptic seizure, there is increase electrical activity in the parietal lobe causing irritation of the center that controls the sensation of the left hand.
• Migraine: sometimes migraines are accompanied by neurological changes (complicated migraines). Among the most common symptoms associated with migraines a change in the vision (patients see lights), weakness, speech difficulties or problems with sensations (numbness). For example, like in our previous example, numbness of the left hand would also have to include a rule out of 1) a complication of a migraine, 2) a TIA or 3) a simple partial seizure. In the case of migraines, there are temporary changes in the amount of blood that goes to the brain.
• Movement disorders: some movements could be confused with seizures. A common example is a tic disorder in which a stereotyped (always similar) movement is seen. An example, left eye twitching could represent a tic disorder or a simple partial seizure with a motor component. Remember that any movement is controlled by the Frontal lobe. So in case of a seizure causing left eye twitching the right frontal lobe will have an increase in the level of electrical activity.
• Sleep disorder: some disorders of sleep could be mistaken with seizures. For example, sleep talking or sleep walking (called parasomnias) are common entities that usually run in the same family. To witness these events can be scary and can easily be mistaken with complex partial seizures. Many people have brief jerking when they fall asleep and they do not have epilepsy. This could be confused with “myoclonic seizures” (a type of generalized seizures-see part 3 of this chapter). In older patients, a disorder called “REM behavior disorder” could be seen which mainly consist in responding to dreams like if they were real. In many occasions, the patient could become violent since he/she does not realize that is experiencing a dream. This could be confused with complex partial seizures during sleep in which patients wake up in the middle of the night and could stare, look confused and have automatic behavior, however rarely aggressive like in “REM behavior disorder”.
• Anxiety/panic disorder: anxiety disorders can have many different presentations. Panic attacks, a type of anxiety episode in which the person feels as if he/she is dying due to intense autonomic reactivity, can be confused with partial seizures that are associated with intense fear.
• Vertigo: these episodes of dizziness may be observed in some disorders that affect the ear. If they are brief and sudden, they could be mistaken with simple partial seizures that have vertigo as part of their manifestation.
• Cardiac disorder: changes in the heart rhythm (arrhythmias) could lead to decreased blood flow and near-fainting or full blown fainting. Both entities, could be mistaken with seizures since if they are prolonged, they could result into a seizure, which most of the times has a clonic component (jerking) followed by a tonic component (stiffening).