Lecture 4 - Seizures (Recorded) PDF

Seizure - definition ◼ A seizure is a sudden surge of electrical activity in the brain. ◼ Uncontrolledelectrical activity in the brain, which may produce a physical convulsion, minor physical signs, thought disturbances, or a combination of symptoms. Normal electrical activity of the brain...

Seizure - definition ◼ A seizure is a sudden surge of electrical activity in the brain. ◼ Uncontrolledelectrical activity in the brain, which may produce a physical convulsion, minor physical signs, thought disturbances, or a combination of symptoms. Normal electrical activity of the brain Measured by electroencephalogram EEG Normal electrical activity of the brain Measured by electroencephalogram EEG What is a seizure? A seizure is defined as a sudden, electrical discharge in the brain causing alterations in behaviour, sensation, or consciousness. ◼ In most brains, neuron interactions occur in a chaotic but balanced, orderly fashion with few disruptions. ◼ Occasionally, small disruptions may occur with little consequence (neuron misfires) ◼ When multiple cells misfire at the same time (depending on the severity and location in the brain) this may cause muscle twitches and spasms. Seizure triggers Any disorder that alters the neuronal environment may cause seizure activity (Craft et al., 2019). Aetiological factors in seizures generally include 1. Cerebral lesions 2. Biochemical disorders 3. Cerebral trauma. 4. Epilepsy which can result from the following conditions Metabolic deficits Congenital malformation Genetic predisposition Common triggers Postnatal trauma Medical events – head injury, CVA, tumour General anaesthetics Myoclonic syndromes Illnesses with a high fever Diarrhoea and vomiting Infection Loud noises and flashing lights Brain tumor Medications (missing medication dose) Fatigue and chronic loss of sleep Vascular disease Over-excitement High stress Fever Heavy usage of alcohol Using drugs and other toxic substances Drug or alcohol use Seizures versus Epilepsy Terms are often used interchangeably, however ◼ Seizure – single occurrence ◼ Epilepsy – two or more unprovoked seizures Videos What is seizure? (4:11 mins) What does a seizure look like? (4:23 mins) Why do seizures happen? (2:16 mins) Types of seizures ◼ Two major classifications of seizures (related to how the seizure begins). ◼ Partial - begin in one location of the brain ◼ Generalised - appear to begin everywhere in the brain at once Types of seizures ◼ Partial and generalised seizures are further broken down into Image: https://amoxicillinamoxilonline.info/29480/seizure-types-chart/types- seizure-types-chart Partial seizures ◼ Partialor focal seizures involve only one portion of the brain. Most common type. Seizures are normally caused because of some physical or psychological cause (head injury, CVA or tumor). ◼ These seizures are called 'partial’ because only one part of the brain is affected, which means the burst of electrical activity is usually limited to one side of the brain. ◼ This form of seizure generally originates in the temporal or the frontal lobe of the brain. Partial seizures ◼ The experience of the seizure is determined by the area of the brain affected. Image: Epilepsy (img :beaumont.edu) Image:http://amoamiamo.com/seizure-types-chart/seizure-types-chart-types-of- seizures-seizuretracker-within/ http://www.rayur.com/epilepsies-definition- causes-symptoms-prevent-and-treatment.html Simple partial seizures A simple partial seizure usually lasts just a few seconds or minutes. ◼ No loss of consciousness ◼ Emotions may be altered ◼ May experience something different and strange about how things feel, hear, look, smell or taste. ◼ May experience some sudden, involuntary jerking of a part of their body (arm or leg). Complex partial seizures ◼ Electrical disturbances affect the person’s awareness and consciousness (a few seconds to several minutes) ◼ Change in LOC - Dazed and confused ◼ Purposeless behavior - random walking, mumbling, lip-smacking, blinking, swallowing, repeated movements, clinging to other people, plucking clothes ◼ Altered emotional state – anxiety, exhilaration ◼ Unusual perceptions ◼ Distorted memory of the event ◼ Most common type of seizure Complex partial Seizures Image:http://www.medicocity.net/complex-partial-seizures Generalised seizures Absence seizures Previously called ‘petit mal’ seizures ◼ These seizures are characterised by staring, loss of facial expression, rolling of eyes, and constant blinking. ◼ During the seizure, the person might just blank out and look like they are daydreaming with their responsiveness/ awareness being affected. ◼ These seizures last only for a few seconds. Tonic-clonic seizures Previously called ‘grand mal’ seizures ◼ These seizures are the kind that most people think of when anyone mentions the word ‘seizure.’ ◼ This seizure usually begins with a loud cry and includes two phases, the tonic phase and the clonic phase. ◼ First, the body stiffens (tonic phase), they lose consciousness and fall down. ◼ Then the clonic phase takes over and their arms and legs will begin to jerk rapidly. ◼ Slowly, they will regain their consciousness and awareness, but they might feel very drowsy and tired. Tonic-clonic Seizures Tonic seizures During a tonic seizure, the body stiffens and if they are standing at the onset of the seizure, they will fall to the ground. ◼ Stiffening of the body. ◼ Arms flex. ◼ Legs, head, and neck extended. ◼ Jaws clamp shut. Myoclonic seizures These seizures are characterised by sudden, very brief muscle jerks in the arms and legs (lasting only a couple of seconds) ◼ Usually involves the upper body - can extend to the whole body. ◼ Arm jerks and twitches Atonic seizures ◼ During an Atonic seizure, the body muscles will suddenly lose strength (tone), and the person may collapse to the ground. ◼ No real loss of consciousness ◼ Collapse or fall may cause injury Diagnosis of a seizure ◼ Difficult to diagnose ◼ By observation of the seizure event (witnessed) ◼ Accurate history of the seizure event or events (not witnessed) ◼ EEG (may or may not be abnormal) ◼ Other investigations ◼ MRI, MRS, PET, fMRI ◼ Neuropsychology ◼ Speech and auditory processing evaluation Measuring seizure activity First Aid Management Image source http://www.epilepsyaustralia.net/seizure-first-aid/ Management Image: http://what-when-how.com/nursing/nervous- https://jamanetwork.com/journals/jama/fullarticle/1738896 system-disorders-adult-care-nursing-part-3/ Treatment - Pharmacological Treatment – non pharmacological ◼ Biofeedback ◼ Surgery ◼ Implanted devices (Vagus nerve stimulation therapy) Image: https://montereybayholistic.wordpress.com/tag/biofeedback/ ◼ Ketogenic diet Image: https://www.mayoclinic.org/tests- procedures/vagus-nerve-stimulation/about/pac- 20384565