9.19 Epilepsy and Seizures and the EEG

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19. Epilepsy & Convulsive Seizures - Scroll down for electroencephalogram, or EEG - Update 13 Septr 2021

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Epilepsy Is

What to do for a Seizure?
Source of Seizures

Brain Surgery for Epilepsy

Anti Convulsion Medication

Other Advices

The Ketogenic Diet

Best Reading on Epilepsy

Electroencephalogram (EEG)

Epilepsy is sudden loss of consciousness with Seizure/Convulsion/Fit. The seizure shows an electrical outburst on the EEG brain wave. The location of the outburst shows source and type of seizure.

In grand mal the victim suddenly falls unconscious with muscle contractions of limbs that cause arms and legs initially to stiffen and then bend and unbend in recurring pattern. Head muscles also are involved at times resulting in biting the tongue.  Sleep and awakening are at particular high risk for starting a grand mal epileptic fit but almost always in a person with past history of fits. Their importance is that the fit may be missed because patient is asleep. Usually, an observer will note the unusual, so called "fencing" movements or note blood from a bitten tongue or soreness. If any question, an EEG should show abnormal waves or a blood test should show high CPK (muscle enzyme). The full-night sleep EEG is a good test for spotting an epileptic who has not yet been observed to have fits.

Another type fit has origin in Brain's frontal cortex and starts on one side of body in hands and moves across to other side with loss of consciousness as it crosses sides.

During a seizure the victim may soil pants.
Types of fit depend on where in brain the electric outburst. Petit mal is a difficult-to-detect temporary loss of contact with the here and now that to observers appears to be a so called “brown study” (Lost in thought). Another type, temporal lobe epilepsy, does not seem to be loss of consciousness; the person having the fit engages in slightly strange behavior (walks up and down, smacks lips repeatedly).

  The fit is due to lowered threshold in the brain's cerebral cortex for irritating stimuli to trigger the electrical outburst and, for essential epilepsy, is probably inherited; in many cases it is caused by an inherited chanellopathy in the neuron synapse involving the cations Na+, K. or Ca++.  The focal types and variants are due to brain scar and local damage from brain tumor and infection; while a third type – the fever or electric shock induced fit – is due to body conditions that excite even normal neurons to electrical outbursts. A fourth type is from medications, toxins and lack of oxygen or due to low blood glucose (hypoglycemia, insulin shock); also faints or heart block.

  Period of life is useful: Classic (essential) epilepsy starts from childhood with no obvious cause. Another set of seizure patients suffer a first fit as adult. It is due to brain tumor or other irritating new lesion in brain and should get an MRI brain imaging. Infants and toddlers get one or a few fits from high body temperature, so called febrile convulsion, or from various infections on surface (meningitis) and in cortex (encephalitis) of brain. First seizures after drug or lack of oxygen are obvious from the preceding circumstance and past history. A first seizure in an adult suggests brain tumor.

What to do for a seizure? Call for help while standing by to protect patient from self injury due to falling down. Most seizures will pass after a minute or two.

   It is important to limit the person's frequency of seizures because each seizure increases the tendency for more seizures (Known as “kindling”, the seizure producing small damage that lowers threshold for another seizure). With any seizure, an emergency ought to be called since one can't be sure of cause or outcome. A first-ever seizure, a seizure after a long period of no seizures or a seizure that lasts more than a minute or repeats needs examinations with EEG, MRI of brain, blood tests, cardiovascular and renal checks and neurological consultation. Diagnosis will be brain tumor or, less commonly, stroke.
   Source of Seizures: Most grand mal seizures are coming from frontal lobe. But seizures that involve emotion or petit mal type are coming from temporal lobe and often produce a particular type of personality: hyposexual, hyper religious or philosophical and with a very so-called viscous (not,”vicious”) manner of speaking or writing (very circumstantial and boring). Temporal lobe epileptics are often good candidates for epilepsy surgery (Temporal lobectomies).
   Anti-convulsion medication should be used by all (Exception is simple febrile convulsion in young child) who have had more than one unexplained convulsions and should be continued for an expert's set period of time seizure free. Go to hospital or top experience clinic like the Mayo Clinic and get your epilepsy checked and set on right road. 
  Brain surgery for epilepsy is increasingly being used. It is reserved for cases that are resistant to usual anti-convulsion medications, and to special types of seizure disorders where MRI and special neuroimaging reveals a surgically removable lesion. Results have been good with low side effects but one should go for top neurosurgery and get careful preliminary check up with advanced EEG and MRI. 

Other Advices: Pyridoxine (vit. B6) deficiency has caused seizures so check blood test and if low or borderline, take vitamin B6. Also alcohol-, barbiturate- and diazepam-withdrawals cause seizures so moderation without sudden stopping is best. Stimulants like Ritalin or amphets or cocaine and also psychedelics like LSD and even marijuana are a No-No for an epileptic. Also prolonged sleeplessness not good
   Self Psychoanalysis (Click 9.33 Psychoanalysis - Secret of Do It Yourself) is important to determine the direction of your life and its limitations especially if you have epilepsy.
  The ketogennic diet (achieved by initial 24- to 48-hour fast and then high vegetable oil diet; it causes an acidosis of the blood and strikingly reduces the incidence of seizures).  The good affect of acidosis suggests high vitamin C daily dose 6 grams.
  Best reading on epilepsy even for a non medical person, is Adams and Victor's Principles of Neurology, the latest 11th ed, by Ropper, Samuels, Klein and Prasad, chapter 15, (Chapter 16 in 10th ed.) Epilepsy and other Seizure Disorders. For a person or family or seminar group that suffers or studies epilepsy.

Electroencephalogram (EEG),discoverer by German psychiatrist Hans Berger in 1924, gives graphic tracing of electrical activity over scalp which comes from the neural electrical activity in the near brain surface cerebral cortex neurons and is also influenced by deeper anatomic brain structures like the thalamus and the brainstem reticular formation. The EEG is useful in diagnosing an epileptic fit, or tendency to get one by showing the electrical outburst spikes, and also to establish a diagnosis of brain death in comatose patient so that family may make decision to terminate medical treatment. It can be useful to the older person as a routine yearly check for abnormality—-a repeated yearly normal EEG should be used to reduce worry about Alzheimer Disease or other dementia or tumor. Although less sensitive than MRI, it is non invasive, much less expensive and easy to get; so it can be repeated much more frequently than MRI. Note that older persons have a high incidence of minor EEG abnormalities, mainly slight slowing of the normal frequencies but these are only worrisome if they progress yearly or give clinical symptoms.  Old age EEG slowing should always be compared to the person's clinical condition, i.e., not to worry in case of mildly abnormal EEG in aging when memory remains good.

   In doing an EEG, many silver electrodes 0.5 cm (<1/4 inch) diameter are pasted in rows on regions of the scalp. (The hair does not need to be shaved.) The electrodes record several wave forms, which are caused by electrical potential differences between the underlying cerebral cortex and a neutral ground electrode (each wave amplitude measured in millivolts, mV). The various EEG wave rhythms are categorized by the frequency of wave peaks, or cycles per second (called “Hertz”, or Hz) and the height or amplitude of the waves from each region, and the EEG waves are recorded on a TV monitor and stored in computer or printed out on a sheet. The wave frequencies in an EEG are from 0.5 to 50 Hz. The record from the right side of brain is compared to equivalent regions left side. Patient is examined initially relaxed in chair or bed with eyes closed and minimal activity. The EEG runs for 30 or so minutes, but continuous 24-hour, sleep/wake recordings during a person’s daily life can be made with portable equipment.

   The result of EEG as normal or abnormal is based on location of typical EEG rhythms from rows of scalp leads, also on left/right symmetry/asymmetry, and on the wave frequencies and amplitudes.
   The wave frequencies are: 1) The normal default condition with eyes closed is between 7.5 to 12.5 Hz waves, and amplitude 50 mV (alpha waves) in both occipital and parietal regions and are suppressed completely with eye opening or mental activity. Recently, alpha is divided into alpha-1, 7.5 to 10Hz and alpha-2, 10 to 12.5 Hz; 2), then, 12.5 to 25 Hz with lower height amplitude waves 10 to 20 mV (beta waves), normal from frontal region and should be symmetrical.  3) A slower wave type 3.5 to 7.5 Hz (theta waves) may normally be seen over the temporal regions more so over age 60; 4) More isolated wave spikes 0.5 to 3.5 Hz (called delta activity), normal during deep sleep but if seen while awake may be a sign of epilepsy, drug use, or dementia; and 5) the fastest frequency 25 to 50 Hz, (the gamma) is always abnormal.
  After a run in the default (relaxed, supine, eyes closed) condition, recordings are done with eyes open, with strong mental activity and then a flashing light. The frequency of the flash will be mirrored by the EEG wave, changing to the same frequency. Especially in an epileptic, this may stimulate an epileptic electrical outburst so this is used to test for epilepsy where seizures have not been observed but the condition is suspect. Also, 3 minutes of instructed hyperventilation (deep, rapid breathing) is done. It may bring on an epileptic outburst but does not usually cause a seizure.

   The Quantitative EEG (QEEG) uses computer assist and is on the cutting edge of neuropsychiatric research. It is not usually available, being done only for research. (See Sadock Comprehensive Text. Psychiatry, IV, section on QEEG from Index)
  EEG is being used in research on "What is consciousness?"
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