052 diagnosis and classication of seizure and epilepsy
TRANSCRIPT
Diagnosis and Classification of Seizures and Epilepsy
Youmans chapter 52
Outline
• Seizure and Epilepsy Classification• Diagnosis of Epilepsy
Seizure and Epilepsy Classification
• Partial seizure• Generalized seizure• Cause of epilepsy
Partial seizure• Those in which the first clinical and electrographic
changes indicate initial activation of a system of neurons in one hemisphere and are subclassified based on the presence or absence of impairment of consciousness
• Simple partial seizures are associated with minimal change in awareness, as indicated clinically by the patient’s complete recollection of the event
• Complex partial seizures are characterized by alteration of awareness and amnesia for at least a portion of the seizure
Partial seizure• Motor, autonomic, somatosensory, special sensory, or
psychic• Both simple and complex partial seizures can propagate
throughout the brain to become secondarily generalized seizures
Generalized seizure• those in which the first clinical changes indicate initial
involvement of both hemispheres• Subclassification : absence, myoclonic, clonic, tonic,
tonic-clonic, and atonic seizures.
Absence(petit-mal seizuire)
• Impair consciousness with mild or no motor involvement
• Typical absence • Atypical absence : more heterogenous with
more variable EEG pattern then typical absence,seizure may be longer
Cause of epilepsy
• Cerebrovascular disease,most frequently, senior adults
• Developmental disorders, neonates and young children
• Head trauma, adolescents and adults• Brain tumor, adolescents and adults• Infection, neonates and young children• Degenerative disorders
Diagnosis of Epilepsy• two unprovoked seizures occurring more than 24 hours
apart• ILAE recently proposed that
– “epilepsy is a disorder of the brain characterized by an enduring predisposition to generate epileptic seizures and by the neurobiologic, cognitive, psychological, and social consequences of this condition. The definition of epilepsy requires the occurrence of at least one epileptic seizure”
Diagnosis of Epilepsy
• History of the experience of the seizure (especially the aura, or initial symptoms), description by a reliable witness
• Physical examination• Electroencephalogram (EEG)• Structural neuroimaging
Approach to the First Seizure Acute evaluation
• If mental status and the neurological examination have not normalized within minutes after the event appears to end– First, is there an underlying medical or neurological
condition that requires immediate treatment? – Second, has the seizure ended?
• Serum glucose, sodium, urea nitrogen, creatinine, and calcium and hepatic enzyme concentrations
• Arterial blood pH, oxygen, and carbon dioxide are important to measure
Approach to the First Seizure Acute evaluation
• Toxicology : ethyl alcohol, cocaine, amphetamines, benzodiazepines, opioids, phencyclidine, tricyclic antidepressants, and antipsychotic drugs
• Hypothyroidism with myxedema coma in rare case• CT Brain : to exclude a structural cerebral abnormality
such as hemorrhage, tumor, abscess, or contusion• If significant temperature elevation, nuchal rigidity,
leukocytosis, or other signs of possible central nervous system inflammation are present, a lumbar puncture : to exclude infection or subarachnoid hemorrhage.
Approach to the First Seizure Acute evaluation
• If the patient has a possible history of seizures, anticonvulsant medications should be identified and serum concentrations determined.
• EEG : recommended for any patient whose mentation does not begin to normalize within minutes after a witnessed seizure or any patient without clearly defined cause of the mental status change
Approach to the First Seizure Seizure in the ambulatory setting
• The subsequent evaluation aims at answering four questions– Was the paroxysmal change in behavior or symptom
a seizure?– What is the classification of the seizure?– Is there a cause that requires specific treatment?– What is the probability of another seizure?
• cardiac syncope, dysautonomia, conversion disorder, or panic attacks.
Approach to the First Seizure Seizure in the ambulatory setting
• EEG– for every patient in whom a seizure is a reasonable
diagnosis• Magnetic resonance imaging (MRI)
– recommended for these patients unless the clinical history, family history, and EEG strongly indicate a primary generalized epilepsy or a definite nontraumatic provocation such as transient hypoglycemia is known
Component of the seizure experience
• Aura : patient is often aware of the initial evolution of seizure
• Visceral/abdominal– Ascending sense of constriction or warm in the
abdominal region epigastric sensation– “I feel like I am dropping quickly in an elevator” or “it
feels like the drop on a rollercoaster ride.
Component of the seizure experience
• Psychic– déjà vu– sense of dissociation from the environment– Depersonalization– sense of never being in a familiar place (jamais vu)
• Special sensory– Olfactory– Less frequently gustatory
• Somatosensory auras– tingling or electrical sensation– contralateral to a parietal epileptogenic region
Component of the seizure experience
• Visual– formed or unformed hallucinations– visual distortion such as change in size or apparent
speed of motion– It is important to understand that seizures arising from
the region of the visual cortex my not have visual auras and that visual auras can occur with seizures beginning in areas other than the occipital lobe
Clinical Semiology
• Mesial temporal lobe– Ipsilateral motor automatisms(tapping, patting, or
rubbing movements)– contralateral dystonic flexor posturing of the wrist and
hand• Temporal lobe
– Oral automatisms such as lip smacking, licking, or repetitive swallowing
– Complete behavior arrest
Clinical Semiology
• Lateral premotor seizures– Focal tonic or clonic motor seizures
• orbitofrontal or frontopolar seizures– hypermotor/frenetic (“motor agitation”) behavior
Lateralizing and localizing semiology
• Lateralizing = side of cerebral hemisphere• Localizing = location• Ictal symptomatogenic zone,these may be ictal onset
zone or ictal propagation• It should be consider with EEG and imaging
• วทิยาการโรคลมชกั, ชยัชน โลวเ์จรญิกลู
Highly reliable lateralizing semiology
• Dystonic limb posturing– contralateral hemispheric lateralization– 100% in temporal lobe epilepsy(TLE)– Electric from contralateral basal ganglion– Not use in tonic limb posturing and unilateral immobile limb
because not accurate
• Unilateral limb automatism– Ipsilateral hemispheric lateralization– 80%, more accuracy with dystonic limb posturing – Contralateral dystonic posturing with ipsilateral automatism can
distinguish mesial temporal lobe epilepsy from neocortical temporal lobe epilepsy
• วทิยาการโรคลมชกั, ชยัชน โลวเ์จรญิกลู
Highly reliable lateralizing semiology
• Version– contralateral hemispheric lateralization– TLE, symptom develop after seizure 30 s then secondary GTC
following : 100%– FLE,symptom develop initial seizure : 91% , with clonic
seizure ,twitching of facial expression contralateral, mouth deviation to contralateral
– Early head turning : not accuracy in lateralization– Late ipsiversion : ipsilateral direction, develop in late GTC
• วทิยาการโรคลมชกั, ชยัชน โลวเ์จรญิกลู
Highly reliable lateralizing semiology
• Unilateral clonic– Contralateral lateralization motor cortex– FTL or neocortical TLE
• Automatism with preserve responsiness(AVR)– Non-speech dominant in TLE
• Asymmetrical tonic limb posturing(ATLP) or figure 4 sign– 66% in focal epilepsy(53% in extra temporal epilepsy and 75% in
TLE)– Contralateral lateralization to tonic limb, 91% TLE, 88% ETE
• วทิยาการโรคลมชกั, ชยัชน โลวเ์จรญิกลู
Highly reliable lateralizing semiology
• Asymmetrical clonic ending of secondarily GTC• 43% in MTLE• Ipsilateral hemispheric lateralization to upper limb that stop seizure
later
• Postictal nose wiping(PINW) or rubbing• TLE > ETE• Temporal lobe ipsilateral to hand that rub nose• More accuracy in rubbing more than one time
• Postictal(Todd’s) paralysis• 13.4%, irritating contralateral motor cortex• Contralateral hemispheric lateralization• 100%-77% have motor seizure(unilateral clonic seizure,dystonic
posturing)
• วทิยาการโรคลมชกั, ชยัชน โลวเ์จรญิกลู
Highly reliable lateralizing semiology
• Postictal aphasia– TLE, ipsilateral lateralization to speech dominant
• Postictal heminnopsia– Contralateral lateralization– Occipital lobe
• Ictal speech– 90% TLE, non-speech dominat
• Olfactory aura– 10% in focal epilepsy– Mesial temporal lobe, amygdala
Highly reliable lateralizing semiology
contralateral ipsilateral1.Dystonic limb posturing2.Version3.Unilateral clonic4.Asymmetrical tonic limb posturing(ATLP)5.Postictal(Todd’s) paralysis6.Postictal heminnopsia
1.Unilateral limb automatism2.Asymmetrical clonic ending of secondarily GTC3.Postictal nose wiping(PINW) or rubbing
• วทิยาการโรคลมชกั, ชยัชน โลวเ์จรญิกลู
Rarely reported and less reliable lateralizing semiology
• Ictus emeticus(ictal vomiting) 9/31– Rt.cerebral hemisphere,100%– Postictal vomiting, no significant
• Unilateral blinking 14/930– ipsilateral lateralization– TLE,ELE
• Ictal smile 5%– Rt.cerebral hemisphere, posterior cortex
• Somatosensory aura 11%– Contralateral temporal lobe(80%)
• วทิยาการโรคลมชกั, ชยัชน โลวเ์จรญิกลู
Rarely reported and less reliable lateralizing semiology
• Ictal/postictal coughing 11%– Lt.cerebral hemisphere– TLE, ETE
• Preictal headache– TLE, ipsilateral lateralization 9/10– TLE FLE,contralateral lateralization 1
• Gyratory seizure 5%– Contralateral to side that turn– TLE, FLE
• วทิยาการโรคลมชกั, ชยัชน โลวเ์จรญิกลู
Rarely reported and less reliable lateralizing semiology
• Ictal urinary urge 2/12– Nondominant temporal lobe, insular cortex
• Peri-ictal water drinking– Nondominant temporal hemispere
• Orgasmic aura– Rt.cerebral hemisphere
• Ictal splitting 2%– Lt.temporal lobe
• วทิยาการโรคลมชกั, ชยัชน โลวเ์จรญิกลู
Rarely reported and less reliable lateralizing semiology
• Ictal lateral tongue biting– Ipsilateral lateralization to tongue biting
• Lateral bradycardia– Temporal lobe,no lateralization
• Prolong post-ictal confusion– Amygdala, TLE
• Unilateral piloerection 0.4%– Ipsilateral lateralization to piloerection– TLE
• วทิยาการโรคลมชกั, ชยัชน โลวเ์จรญิกลู
Physical examinationPhy• Commonly normal• Some neurological syndromes are often associated with
seizures and specific physical abnormalities• tuberous sclerosis complex : facial angiofibromas,
hypomelanotic macules, shagreen patches, ungual fibromas, and retinal hamartomas
• neurofibromatosis type 1 : café au lait spots, axillary freckling, cutaneous neurofibromas, and iris hamartomas (Lisch nodules)
• Temporal lobe epilepsy : frequenly but overlooked– Asymmetrical facial movement with spontaneous smiling
Physical examinationPhy
Electroencephalography• Indispensible• Various type• Single EEG sensitivity 50%, third record > 90 %• Interictal sharp wave : mesial temporal origin
Neuroimaging• First Goal : exclude a progressive od dangerous lesion
such as tumour or AVM• MRI to be superior to CT in identifying small
– T1-weighted scans with short repetition time/echo time (TR/TE) : anatomic relationships with superior resolution
– T2-weighted long TR/TE : more sensitive for focal pathology– New strategies such as “short flip angle” scans have been
suggested to identify small calcifications or hemorrhages.
Thank you
• The anatomic location of the wound has also been shown to have an impact on the incidence of infection, with head and scalp wounds exhibiting the lowest rate of infection and the foot the highest rate. This is probably due to the inherent colonization of bacteria and difference in tissue vascularity that characterizes the foot and the face