Seizures Flashcards
Paracentral seizures
Originate on mesial surface of parietal lobe, CL genital sensations & postural motor activity, frequently seconarily generative
Risk factors for psychogenic seizures
H/o sexual abuse, epilepsy, psych disorder, head injury/PCS, model for seizure disorder, traumatic life course, family discord/academic stress
Common etiologies of perinatal seizures
Toxemia, infection, congenital defects, difficult birth
Possible distinguishing semiology for pseudoseizures
Acute emotional disturbance may initiate, rare when sleeping or alone, gradual onset, crying during ictus, occasional talking, asynchronous mvmts, react to avoidance testing, personal injury rare, infrequent micturition & defecation, no ictal epileptiform EEG abnormality
Seizures in the frontal opercular region
Epigastric aura, fear, salivation, repetitive chewing mvmts, repetitive swallowing, speech arrest, autonomic symptoms
Todd’s paresis
Focal loss of function in whatever region just experience a seizure; loss of motor function is most common, can range from weakness to full paralysis
What is the most common type of seizure?
Complex partial
Factors that increase risk of cognitive deficits in seizure disorders
AED toxicity, symptomatic epilepsy, seizure type & frequency, younger age at onset, poor control, temporal lobe epilepsy surgery
Tonic seizures
Sudden onset of bilateral tonic extension or flexion of the head, trunk, or extremities for several seconds; typically occur during drowsiness or just after falling asleep/waking up
Early signs of mesial temporal lobe seizure
Staring, behavioral arrest, automatisms, motor restlessness, nonforced head deviation
Orbitofrontal lobe seizures
Usu. complex partial seizures that being with motor or gestural automatisms, peri-ictal urination is typical, may see vocalizations, intense fear, complex motor acts
Cognitive effects of Tegretol
May improve processing speed, psychomotor speed, problem-solving & decrease aggression & emotional lability
Neurological & demographic variables that are predictive of post-surgical seizure freedom
Unilateral EEG abnormalities, presence of exclusively IL temporal inter-ictal epileptiform discharges, presence of structural abnormalities, younger age at time of surgery, shorter duration of pre-operative epilepsy
Variables improving quality of life among epilepsy patients
Reducing seizure frequency, reducing AEDs, promote cognitive reserve/activity, decrease psychiatric symptomatology, reduce family/social/cultural stigma/discrimination
Jacksonian motor seizure
Simple partial seizure in which motor symptoms progress or ‘march’ from fingers to arm to face
Supplementary motor area seizures
Brief, typically include postural symptoms, often refractory to AEDs
Absence seizures (petit mal)
Brief episodes of impairment of consciousness with no warning & short duration no aura or post-ictal fatigue
Late signs of mesial temporal lobe seizure
Arrest reaction, restlessness, staring, dystonic posturing of arms
EEG alpha waves
8-13 CPS/hz Normal dominant/background activity, reflects an anxiety-free state Lost with eye opening, falling asleep, meds that affect mental function, slows in elderly & in nearly ever brain-based neuro illness
Most common underlying pathology of mesial temporal lobe epilepsy
Mesial temporal lobe sclerosis
Cognitive side effects of Dilantin
Psychomotor speed, memory & problem solving; may result in progressive encephalopathy w/ accompanying deterioration in intellectual fx
Which anticonvulsant has the worst cognitive side effects?
Topamax
Simple partial seizures
Involve at least 1 focal area of the brain, do not impair consciousness
Corpus callostomy is limited to pts with what types of seizures
Unknown seizure focus or multiple seizure foci with debilitating seizures that are frequently atonic/clonic in nature
Childhood absence epilepsy
Onset 4-8 years old, may remit in adulthood Seizures are brief staring spells w/ loss of awareness Increased rates of LDs, ADHD, anxiety d/o, mild deficits in attention/exec, delayed & immediate memory, visuospatial
EEG beta waves
>13 hz; prominent with concentration, anxiety, under effects of minor tranquilizers
The majority of refractory epilepsies have focal seizures that arise from where?
Temporal lobe
Lennox-Gastaut syndrome
Onset ages 2-8 yrs Triad: atonic, atypical absence, tonic seizures MR, autistic features, bx problems common, developmental delay can predate onset of seizures or become apparent later Common to have multiple seizures daily, status epilepticus is common
Risk factors for complex febrile seizures evolving into later seizures
Family hx of afebrile seizures, some kind of neuro involvement prior to febrile seizures, abnormal EEG
Occipital lobe epilepsy
Elementary visual hallucinations usually in periphery of CL visual field Amaurosis, scotomas, hemianopsias, quadrantanopsias Tonic/clonic eye deviation, head deviation, blinking, sensation of eye mvmt, nystagmoid eye mvmts Typically spread to temporal, frontal, supplementary motor, or parietal areas
Complex partial seizure
Involve at least 1 focal area of the brain, impair awareness/responses to environmental stimuli Typically starts as simple partial (aura), lasts 30 sec-2 mins
Cryptogenic seizure disorder
Related to a structural abnormality that is not identifiable with current available methods
Common etiologies of seizures in young adults
Trauma, ETOH, neoplasm, drug-related, AVM, AIDS
Common etiologies of seizures in middle aged adults
Neoplasm, ETOH, vascular disorder, trauma
Atonic seizures
Brief loss of muscle tone of the postural muscles
Autosomal dominant nocturnal frontal lobe epilepsy
-Begins in childhood/adolescence -Spells occur in clusters during sleep -Typically begin w/ aura, evolve into prominent motor phenomena
Juvenile myoclonic epilepsy
-Cardinal feature: myoclonus w/ preserved awareness -Triad of seizure types: myoclonus, generalized tonic-clonic, absence -NP deficits: generally mild, processing speed, attention/wm, lang, mem, visuospatial, & exec fx reported -Most consistent deficit is exec fx, typically not present in adulthood
Post-ictally, EEGs show
Low voltage activity (postictal depression) followed by diffuse high voltage slowing
Vagus nerve stimulator
Chronic stimulation of the L vagal nerve by electrode implantation & programmable signal generator placed subdermally under the clavicle
Most important predictors of quality of life among epilepsy patients
perceived seizure frequency, perceived adverse effects of AEDs, perceived cognitive problems due to epilepsy and/or AEDs, limitations in independence
Which anticonvulsant drug has been linked to hyperactivity, irritability, & sleep deprivation?
Phenobarbital
Up to what percentage of individuals with known epileptic disorders will not show abnormalities on the typical in-office brief EEG?
60%
Multiple subpial transaction
Horizontal axonal fiber tracts in the brain are transected while preserving the vertical oriented axonal fiber tracts; offered to pts w/ seizure focus in eloquent cortex
Risk factors for epilepsy surgery failure
Presence of B EEG abnormalities, presence of secondarily generalized tonic-clonic seizures with TLE, no structural pathology w/ high resolution MRI, CL memory function intact on Wada (TLE only)
Juvenile absence epilepsy
Typically begin around puberty, frequency less than childhood variety, consciousness less affected, tonic-clonic seizures more frequent (these tend to persist, while absence decrease/disappear with age)
Common etiologies of seizures in late life
Vascular disorder, neoplasm, degenerative, cysticercosis, CVA most common after age 65
Idiopathic seizure disorder
Presumed genetic; thought to reflect molecular dysfx
Precentral frontal lobe seizures
Begin in primary motor cortex, may consist of simple partial or myoclonic jerks w/ or w/o secondary generalized tonic-clonic convulsions; postictal paralysis of affected body part is common
Ictal EEGs show
Paroxysmal activity consisting of spikes, slow waves, or complexes of spikes & waves or poly-spikes & waves
Automatism
Simple & repetitive actions that are not mediated by conscious intention; common ones seen in complex partial seizures include lip smacking or repetitive hand movements
What percent of the population has nonspecific EEG changes?
15%
Symptomatic seizure disorder
Related to a known structural abnormality
Postcentral gyrus seizures
Almost always assoc. w/ aura of positive (or negative) sensations, many objective signs depend on where seizure spreads outside of parietal lobe
Premotor frontal lobe seizures
Originate in lateral/medial premotor frontal regions, characterized by tonic & postural motor phenomena most common in UEs
Most common neurocognitive effects of AEDs
Sustained attention, secondary learning & memory effects
Familial seizure disorder
Demonstrated to be genetic; typically autosomal dominant
Benign rolandic epilepsy
-Age limited (often remit by 16 yrs old) -Onset 3-13 -Seizures arise from centrotemporal region -Tonic-clonic in nature (most frequently facial twitching); can have UL parathesias & speech arrest
Inferior parietal seizures
May give rise to sexual sensations, severe vertigo, abdominal sensations, gustatory hallucinations, apraxias, disturbances of body image, spatial disorientation
Frontal lobe epilepsy
Rapid secondary generalization, focal clonic motor activity, prominent asymmetric tonic posturing, explosive onset & sudden ending, minimal post-ictal confusion, frequent & brief seizures that occur in clusters
Good prognostic features of neuropsychological outcome following epilepsy surgery
Presence of lesion IL to seizure focus, unilateral EEG abnormalities, presurgical lateralizing NP data in which memory impaired for IL temporal lobe, longer duration of epilepsy, higher presurgical cognitive ability, asymmetric fx neuroimaging findings, memory good on Wada IL injection
Dorsolateral frontal lobe seizures
Forced thinking, loss of contact w/ & awareness of surroundings, CL adverse deviation of head & eyes, tonic movements, speech arrest
Focal (partial) seizures
Begin in a focal area of the cortex & are usually associated with underlying structural abnormality
Primary generalized tonic-clonic seizures (grand mal)
Tonic extension of extremities for about 20 secs followed by clonic synchronous rhythmic muscle mvmts generally lasting about 45 secs
Secondary generalized seizures
From simple or complex, spreads across CC to entire cortex
Clonic seizures
Brief rhythmic jerking mvmts of the muscles frequently affecting both UEs & LEs during which consciousness is impaired
Predicting confrontation naming outcomes following epilepsy surgery
Reliable decline in naming more likely for patients w/ resection of language dominant temporal lobe & intact naming score and/or shorter duration of epilepsy Reliable decline less likely w/ presurgical naming deficits & longer duration of epilepsy
Which types of seizures carry an increased risk of cognitive deficits?
Tonic/clonic, atypical absence, mixed
Seizures in the anterior cingulate gyrus
Usu. complex partial seizures with complex motor & gestural automatisms; autonomic hyperarousal signs & changes in mood/affect common
Common etiologies of seizures in young children
Congenital abnormality, neonatal meningitis, neurocutaneous disorders
West’s syndrome (infantile spasms)
Onset b/t 6-18 mos of age, usu. cease by 2-4, 25-60% give rise to other types of seizures Clinical triad: infantile spasms, developmental arrest, hypsarhthmia EEG pattern MR, autistic features, behavioral problems common
The most consistent neuropsychological deficit seen in childhood absence epilepsy is
Visual memory deficits
Myoclonic seizures
Sudden, shock-like muscle contractions lasting only a fraction of a second
Generalized seizures
No aura, no focal semiology, no lateralized findings, no focal EEG abnormalities; immediate LOC
Anterior temporal lobectomy
Surgical resection in which the anterior temporal lobe is resected en bloc
Risk factors for post-op decline in verbal memory following anterior temporal lobectomy
Dominant hemisphere resection, intact pre-op NP memory testing, intact pre-op Wada memory testing, absence of mesial temporal sclerosis on imaging
What percentage of patients experience seizure freedom with surgical resection?
70%
Landau-Kleffner syndrome
Gradual or sudden onset of auditory agnosia that may involve total unresponsiveness to language or progressive deterioration of expressive speech Language decline may precede presentation of seizures, recovery of lang fx strongly related to age of onset (
Common etiologies of seizures in adolescents
Idiopathic, trauma, drug-related
EEG theta & delta waves
Theta = 4-7 hz Delta = 1-3 hz Detected in children & everyone entering deep sleep; generally absent in healthy, alert adults May indicate a degenerative illness or metabolic derangement, focal presence may suggest lesion in that region
Which anticonvulsants have the least side effects?
Keppra, neurontin, Lamictal
Other conditions that mimic seizures
Episodic dyscontrol syndrome, cerebrovascular disturbance, panic disorder, breath-holding spells in infants, sleep disorders, migraine, metabolic disturbances
Multiple subpial transaction
Horizontal axonal fiber tracts in the brain are transected while preserving the vertical oriented axonal fiber tracts; offered to patients the seizure focus in eloquent cortex
Posterior parietal seizures
Primarily involve BA 5&7 Prominent staring & relative immobility, visual phenomena may occur
