Paroxysmal Dyskinesias


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Paroxysmal Dyskinesias

  1. 1. PGR 2008.9.2 Pediatric Neurology Seoul National University Children’s Hospital Seoul, Korea
  2. 2. • Frontal lobe epilepsies (FLE) manifest with seizures originating from a primary epileptic focus anywhere within the frontal lobe • Demographic data  Start at any age and both sexes equally affected  1-2% of all epilepsies  Second (20-30%) after TLE in neurosurgical series
  3. 3.  Supplementary motor area (SMA) seizures  Cingulate seizures  Anterior frontopolar seizures  Orbitofrontal seizures  Dorsolateral seizures  Opercular seizures  Motor cortex seizures
  4. 4. • Prominence of motor manifestations-automatisms as well as tonic-clonic activity • Rapid secondary generalization-little or no evidence of focal onset • Focal clonic motor activity with or without march • Prominent asymmetric tonic posturing • Complex, bizarre motor automatisms • Explosive onset and sudden ending with minimal postictal confusion • Frequent, brief seizures often in clusters
  5. 5. • Mainly simple motor seizures • Simple focal motor clonic or tonic-clonic seizures with or without jacksonian march  Localized, rhythmic or arrhythmic, clonic movements contralateral to the focus  Distal > proximal  Hand (thumb) and face (lips) preferentially affected (homunculus of Penfield)  Remain highly localized or march to neighboring motor regions (jacksonian march) • Myoclonic seizures: predominantly facial or distal in the limbs • Tonic postural motor seizures
  6. 6. • Frequent, brief episodes occurring in clusters • Explosive onset and offset with no postictal confusion • Nocturnal preponderance • Prominent tonic posturing, usually of the contralateral upper extremity • Contraversive head and eye deviation • Fencing or M2e posture • Preservation of consciousness in some • Postictal Todd’s paresis (mild)
  7. 7. • Frequent, brief seizures occurring in clusters • Sudden onset and offset with little or no postictal confusion: consciousness partially retained but commonly amnesic for episodes • Nocturnal preponderance • Complex motor automatisms-semipurposeful motor activity often in combination with tonic-clonic motor manifestations • Vocalization from simple humming to shouted expletives • Prominent mood changes • Sexual automatisms • Overall bizarre hysterical appearance “pseudovoluntary nature” • Commonly misdiagnosed as psychogenic attacks
  8. 8.  Frontal lobe seizures: generally thought to be brief, motor phenomena, cluster in sleep  But, variable among the cases  Distinguishing features of temporal lobe seizures  Presence of epigastric auras and hand automatism  rarely seen in FLE  Longer post-ictal periods of drowsiness or confusion
  9. 9.  Have failed to attain adequate seizure control with adequate trials of anticonvulsant drugs (drug- resistant epilepsy)  Suffer from surgically remediable syndromes  Have a reasonable chance of benefiting from surgery
  10. 10.  Absolute contraindication  Underlying degenerative or metabolic disorders  Supervening medical illness  Benign epilepsy syndromes: benign rolandic epilepsy, benign focal epilepsy of childhood with occipital spikes  Relative contraindication  Medication noncompliance  Interictal psychosis  Severely dysfunctional family dynamic
  11. 11. Correct seizure type and epilepsy syndrome diagnosed Optimal use of at least two AEDs appropriate for seizure type Good compliance with the medications Absence of major medical or psychosocial disturbance that interferes with seizure control Seizure control or improvement is likely to reverse disability or improve quality of life
  12. 12.  Concept introduced to promote early surgical intervention for certain forms of epilepsy with well-defined pathophysiological substrates that are known to have a poor prognosis after failure of a few AEDs and an excellent surgical prognosis  Mesial temporal lobe epilepsy with hippocampal sclerosis (hippocampal epilepsy)  Certain temporal or extratemporal neocortical symptomatic focal syndromes with discrete easily resectable structural lesions  Epilepsies of infants and small children that can be treated with hemispherectomy  Lesional vs. Non-lesional
  13. 13.  Hippocampal sclerosis  Neoplastic lesions  Neuronal and glial neoplasm: Ganglioglioma, DNET  Glial neoplasm: Pilocytic astrocytoma, Low-grade astrocytomas, Pleomorphic xanthoastro cytoma, Oligodendroglioma, Oligoastrocytoma  Developmental lesions  Malformations of cortical development  Focal malformations of cortical development  Periventricular heterotopia  Polymicrogyria and schizencephaly  Tuberous sclerosis complex  Hypothalamic hamartoma  Vascular lesions: Arteriovenous malformations, Cavernous angioma  Chronic inflammatory focal lesions: Tuberculoma, Cysticercosis  Focal encephalomalacias  Large hemispheric lesions  Rasmussen encephalitis  Hemimegalencephaly/hemi-hemimegalencephaly  Hemiconvulsion-hemiplegia-epilepsy syndrome  Sturge-Weber syndrome
  14. 14.  Nonlesional epilepsy syndromes: recurrent seizure disorder not due to a structural tissue lesion that replaces the volume of the normal brain anatomy  Lesion: structural alterations that can be visually identified by imaging studies before the surgery  Does not preclude that the tissue may possess microscopic or histologic abnormalities  Presurgical evaluation: more complex, due to the lack of any anatomical evidence for the origin of the seizures  Operative outcome less favorable than those with MRI- identified epileptogenic lesions
  15. 15. Well-circumscribed structural lesion on MRI Well-localized interictal epileptiform discharges on EEG Clinical features of habitual seizures indicating frontal onset Absence of discordance between the above features The focus suggested by above features is surgically accessible and involves little or no eloquent cortex Absence of other potentially epileptogenic abnormalities
  16. 16. Area Definition Mode of definition Epileptogenic lesion Structural brain abnormality that is the dire ct cause of seizures Structural imaging, tissue path ology Irritative (spiking) zone Area that generates interictal spikes EEG and MEG Ictal onset zone Area of cortex that generates seizures EEG and MEG Symptomatogenic zone Area that produces the initial clinical symptomatology History, observation during vid eo-EEG monitoring Functional deficit zone Cortical area with functional abnormalities Neurologic examination, neuro psychological testing, EEG, M EG, PET, SPECT Epileptogenic zone Area of brain that is necessary for generating seizures and whose removal or disconnection abolishes seizures Theoretical concept
  17. 17. • Zone resected at surgery, ideally it should be identical to epileptogenic zone but is often larger due to uncertainty in completely localizing the epileptogenic zone and at times may exclude some areas of the epileptogenic zone to avoid resection of eloquent areas
  18. 18.  Prognostic factor to show good surgical outcome  Potentially epileptogenic lesion in neuroimaging  Absence of febrile seizures, generalized or bilateral epileptiform activity on surface EEG widespread epileptiform activity in ECoG  Neoplasm as etiology  Strong predictor for poor outcome  Residual epileptogenic tissue as assessed by seizures/frequent spikes ECoG or MRI
  19. 19.  Immediate complication: Intracranial or scalp/skull infections, hemorrhage, edema, neurological deficits and seizures in up to 20-25% ~ 40-50%  Permanent neurological deficits in 2-3% of the patients