Seizure types Flashcards
What are some of the typical features of seizures emanating from the mesial temporal lobes?
Features of mesial temporal lobe epilepsy: 1. “aura” - rising epigastric sensation - psychic or experiential phenomena (deja vu, fear) - gustatory or olfactory hallucination Auras can occur in isolation or can precede a focal seizure with impairment of consciousness 2. Focal seizures with impairment of consciousness or awareness - usually manifest with a behavioral arrest and staring and last between 30 and 120 seconds. 3. Automatisms - repetitive, stereotyped, purposeless movements. - ie hands (picking, fidgeting, fumbling) and mouth (chewing, lip smacking). 4. Lateralizing features can occur - Unilateral automatisms are usually ipsilateral to the seizure focus, - dystonic posturing almost invariably occurs on the contralateral side. - Head deviation at seizure onset is usually ipsilateral to the seizure; when it occurs later, it is contralateral 5. Postictal confusion usually resolves within minutes. Nose-wiping, performed by the hand ipsilateral to the focus of seizure onset, is a common postictal event in mesial TLE. 6. Heart rate changes commonly accompany temporal lobe seizures.
What are good and bad prognostic factors after temporal lobectomy? What is overall control like?
Good prognostic features after temporal lobectomy include presence of: - mesial temporal sclerosis on MRI of the brain (unilateraly), or presence of localized temporal lobe PET even if brain is NAD - a history of febrile seizures, - unilateral ictal and interictal EEG abnormalities. - presence of a focal brain lesion on MRI - shorter preoperative seizure duration ●Shorter preoperative seizure duration Comorbid psychiatric disease,has been associated with worse postsurgical seizure outcomes. Postoperatively, strongest predictor of long-term seizure control is freedom from seizures in the first year after surgery. The presence of interictal epileptiform discharges on an EEG performed within the first few years after surgery has been associated with an approximately threefold higher risk of recurrent seizures MRI scan mesial temporal sclerosis with temporal lobectomy for intractable epilepsy have 65-75% seizure free for up to 10 years post.
A patient has a complex partial seizures with normal neurological examination. What is the most likely etiology?
With a complex partial seizures with a normal examination, the most likely etiology is mesial temporal sclerosis.
What are some of the features of psychogenic seizures? What is the best step to investigate suspected psychogenic seizures?
(table from up to date) Psychogenic seizures usually: - last longer than 2 minutes - eyes closed (forced close suggests PNES) - forward pelvic thrusting, back arching (opisthotonus), rolling side to side, - activity waxes and wains, is irregular and asynchronous - vocalisation may occur - stuttering, weeping - incontinence less common - autonomic signs less common - may rapidly awaken and reorientate - headache rare The diagnostic procedure that is most likely to be beneficial in differentiating between epilepsy and psychogenic seizures is capturing an episode during video-EEG monitoring
What are the features of juvenile myoclonic epilepsy?
- JME is a generalized epilepsy that typically presents during adolescence or early adulthood. - Patients typically describe a history of morning myoclonic jerks, and generalized seizures. Absence seizures are present in 20 - 40 % beginning up to five years before other seizure types. - Both seizures and the myoclonic jerks commonly are precipitated by sleep deprivation and alcohol. - The classic interictal electroencephalography (EEG) pattern in JME is 4 to 6 Hz bilateral polyspike and slow wave discharges with frontal predominance over a normal background activity. Sensitivity of the EEG rises to nearly 100 percent with overnight recording.
What should be quickly excluded in status?
hypoglycemia. If serum glucose is not immediately available, 50 cc of 50% dextrose should be administered intravenously concurrently with 100 mg of intravenous thiamine
What are the features of frontal lobe epilepsy?
Frontal lobe seizures can be diverse. They are commonly nocturnal and have prominent motor manifestations and automatisms. There may be no postictal confusion.” Common characteristics: - short duration - predilection to occur during sleep - seizure clusters and status epilepticus are more common than with TLE - post ictal state may be brief or absent Types: Focal seizures with impairment of consciousness - hypermotor behaviors (proximal limbs, tonic) - often bizarre looking - bicycling, automatisms (pelvic thrusting and sexual automatisms) - Tonic posturing and head and eye deviation (version), usually contralateral to the side of the seizure focus, - Vocalizations are also very common. seizure auras - common but less ubiquitous than TLE, ill described feeling, fear and anxiety Focal motor seizures involving the primary motor cortex will produce hemiclonic activity in the contralateral face, arm, or leg. Seizures may be quite focal (isolated to one limb or face) or may spread (or march) to adjacent areas (ie, Jacksonian seizure). Supplementary motor area seizures typically produce stereotyped asymmetric tonic movements. - fencing posture, (head deviates contralaterally) Speech arrest may accompany seizures arising from the dominant hemisphere. So-called frontal absence seizures manifest with staring, trance-like states.
What are the most common causes of seizures by decade?
Trauma in 2nd and 3rd decades Brain tumours in 4th decade Stroke in the elderly. - Acute cerebrovascular disease (including hemorrhagic and ischemic events) accounts for 60% of all cases of status epilepticus (SE) in the elderly.
Where to gustatory hallucinations typically arise from?
usually arising from a lesion of the parietal operculum.
After a first seizure - what factors increase risk of another?
After a first unprovoked seizure approx 1/3 will have a recurrent seizure in 5 years. The risk is higher if (2-2.5 fold higher) - Epileptiform abnormalities on interictal EEG - Remote symptomatic cause, as identified by clinical history or neuroimaging (eg, brain tumor, brain malformation, prior central nervous system infection) - Abnormal neurologic examination, including focal findings and intellectual disability - A first seizure that occurs during sleep With the above, risk approaches or exceeds 60% over 10 years, thereby meeting criteria for epilepsy according to the current International League Against Epilepsy (ILAE) definition.
What is SUDEP? What are the RFs for it?
Sudden unexplained death in epilepsy (SUDEP). Remains poorly understood. Most significant risk factors include 1. - uncontrolled generalized tonic-clonic convulsions - higher frequency of seizures - the need for multiple AEDs. - poor medical compliance - use of carbamazepine - mentally handicapped Absence seizures, nonconvulsive seizures, and etiology of the epilepsy, have no known bearing on the risk of SUDEP.
How do you manage drug resistant epilepsy?
Most patients who will respond to medical therapy will do so with the initial anticonvulsant. Medically refractory epilepsy. - traditionally failure of 3 AEDs = medically refractory epilepsy- although evidence that if fail 2 = medically refractory. In a patient who has failed to achieve good seizure control with monotherapy of two appropriate AEDs, or a combination of 2 drugs, the likelihood of response to a third drug is only 5% to 10%. After a trial of 2 x AED patients should be evaluated for alternative forms of therapy, including epilepsy surgery.
How can you monitor an intubated, sedated patient for status? (without EEG)
Intubation and general anesthesia interfere with observation of further seizure activity. pupillary dilatation and hypertension can be signs of ongoing seizure activity. Hypotension, poikilothermia (inability to regulate temp) and hypoventilation are likely secondary to sedative and anesthetic agents.
What is the definition of a late post-traumatic seizure?
“A late posttraumatic seizure is defined as a seizure that occurs more than 1 week after a head injury. Patients with a late posttraumatic seizure are at high risk for recurrent episodes and require long-term treatment with an AED, even after presentation of their first seizure.
Is prolactin level helpful for differentiating pseudoseizures?
For the assessment of true seizure versus pseudoseizure, EEG is indicated in the peri-ictal evaluation. Elevated serum prolactin assay, when measured in the appropriate clinical setting at 10 to 20 minutes after a suspected event, is a useful adjunct for the differentiation of generalized tonic–clonic or complex partial seizure from psychogenic nonepileptic seizure among adults and older children. However, the use of serum prolactin assay has not been established in the evaluation of status epilepticus, repetitive seizures, and neonatal seizures.”
What does this sleep study show? What disease is likely to develop?
This patient has a REM parasomnia, specifically REM sleep behavior disorder (RBD).
Normally, there is atonia (loss of muscle tone) during REM sleep. RBD is characterized by at least intermittent loss of this normal REM atonia as is shown in Figure 5.14B (blue arrow) and by the appearance of complex motor activity during which the patient acts out dreams. Dream content is usually violent with associated movements (e.g., punching, kicking, and running). This can cause injuries to the patient or to the bed partner. The prevalence of RBD increases with increasing age. Over half of patients with RBD go on to develop a neurodegenerative disorder, most often α-synucleinopathies such as Parkinson’s disease, multisystem atrophy, or dementia with Lewy bodies. Of all the disorders listed in question 92, only Parkinson’s disease is an α- synucleopathy. Treatment of RBD includes interventions to minimize risk of injury (such as padding the headboard and bedside table) as well as pharmacologic agents such as melatonin and clonazepam.
