Seizures vs. Muscle Jerk vs. Startle Reflex
From Holoprosencephaly
Seizures vs. Muscle Jerk vs. Startle Reflex
Brain cells called neurons communicate through electrical messages. When the neurons in the brain are working correctly, they send messages from the brain to the rest of the body and respond to messages received from the body through a controlled flow of electrical activity. In contrast, a seizure starts when one or more cells create and send electrical messages that cause inappropriate burst of electrical activity. Sometimes this surge of excessive electrical activity spreads throughout the entire brain. During a seizure, a child may feel, move, or act differently. The seizure will temporarily disturb many of the brain's functions including consciousness, personality, mood, memory, behavior, sensations, and movement. The form of seizures depends on where the unusual electrical activity in the brain begins and how far it spreads. Seizures are diagnosed by a procedure called an electroencephalogram (EEG). This test is used to evaluate the brain's electrical activity. The EEG will often show an abnormal pattern in children that have seizures.
Almost half of children with HPE have seizures. In children with HPE, certain abnormal brain structures can make a child at risk for seizures. There are many potential triggers for seizures; infection, fever, illness, stress, lack of sleep, and flashing lights.
The most common type of seizure is called partial seizure or focal onset seizure. This type of seizure may arise from a specific small area of the brain called the temporal lobe. During a simple partial seizure, the child remains awake and aware throughout the episode whereas a child having a complex partial seizure cannot interact normally with other people.
Seizures involve jerking of the limbs, head, or body. Children with generalized tonic clonic seizures lose consciousness, stiffen, and fall. This is followed by jerking movements of the limbs. There may be loss of bladder and bowel control and the seizure is usually followed by confusion or sleepiness.
Myoclonic seizures are sudden, brief, massive muscle jerks. They can involve just certain parts of the body or the entire body. There is no apparent loss of consciousness although the EEG will be abnormal during the seizure.
Infantile spasms are clusters of quick sudden movement. If seated, the child's head will fall forward and the arms will flex forward. If lying down, the knees may draw up and the arms and head flex forward. Infantile spasms usually start between 3 months and 2 years of age. The EEG will show a specific abnormal pattern of electrical activity. In almost all cases, even untreated, infantile spasms stop by the age of 5 years. However many children will later develop other types of seizures.
An uncomplicated seizure does not seem to cause permanent harm to the brain. Children who have had many uncomplicated seizures show no changes in mental functioning.
Muscle Jerks are also common in children. These jerks are not seizures. Very often, as children fall asleep, their bodies suddenly jerk. This is normal. Additionally, many children with neurological problems have an exaggerated startle reflex and will jerk suddenly if there is a loud noise or movement. These jerks are not seizures. On EEG, there is no change in the electrical activity of the brain suggestive of a seizure.
Nancy J. Clegg, RN, CNS, PhD National Holoprosencephaly Project Director, The Carter Centers for Brain Research in HPE (original submission to HPE Family Newsletter)
Sources:
Epilepsy: A Guide to Living Well (1997) by Celeste Cafiero
Epilepsy: Patient & Family Guide (1994) by Orin Devinsky
If you have any concerns, please don't hesitate to discuss your concerns with your child's doctor(s).
For information about dealing with other potential health problems, treatments and medications, please visit our Miscellaneous Health Information category.
Click here to read what specialists have to say about caring for children with Holoprosencephaly: Doctor Q&A
