Epilepsy Flashcards
- A 23 year old woman with complex partial seizures was Initially treated with phenytoin, then switched to carbamazepine, and is currently on levetiracetam after failing the first two therapies. After a seizure-free period of six months upon starting levetiracetam, she now has recurrence of 2-3 seizures/month. What is the most appropriate next step in her management?
A. Evaluation for vagus nerve stimulation.
B. Add-on therapy with oxcarbazepine.
C. Switch to therapy with oxcarbazepine.
D Evaluation for resective epilepsy surgery
D Evaluation for resective epilepsy surgery
The patient meets the criteria for drug resistant epilepsy (Kwan et al., 201 0), and is unlikely to become seizurefree with further medication trials. The most appropriate next step In her management is evaluation for resective epilepsy surgery.
In a single-institution, prospective, cohort study of 780 adolescents and adults prescribed their first AED from 1982-2001, 50.4%, 10.7%, and 2.7% percent of patients became seizure free for at least one year with the first, second and third treatment schedules, respectively (Mohanraj and Brodie 2006). Some studies show rates of seizure freedom in chronic epilepsy as high as approximately 15%, depending on trial design, how an adequate trial of AED is defined, or use of newer AEDs. However, this is still significantly lower than chances of seizure freedom if she is a candidate for resective epilepsy surgery. Therefore, mono therapy or add-on therapy with drug A is not the best next step, though either of these may be tried in parallel with surgical evaluation.
- A 32 yr old male with intractable seizures and a normal MRI scan undergoes a non Invasive evaluation. Based on scalp EEG and seu:ure semiology, he had subdural electrodes placed and seizures were localized to the left language-dommant supplementary motor area Following surgical resectioo the patient will MOST likely exhibit :
A. Temporary paresis on the left.
B. Left inferior quadrantopsia
C. Temporary Mutism
D. Anosmia and Finger agnosia
C. Temporary Mutism
Resections m the language-dominant SMA often result in post-operative muteness, paresis (on the CONTRALATERAL side - in this case right), and neglect The paresis may be contralateral but can affect bilateral extremities as well The hallmark of these deficits is U1at they are trans~enl They largely resolve within 3-4 weeks of surgery. Therefore if seizures are severe and debilitating, surgical resection may well be medicated after thoroughly counseling the patient about temporary post-operative defiats. Anomia and finger agnosia are characteristic of Gerstmann’s Syndrome, resulting from dominant parietal damage. Inferior
quadrantopsia Is characteristic of damage to the superior component of the optic radiations. in the parietooccipital lobe.
- Patients with subcortical band heterotopia are characterized by:
A. Male predominance.
B. Subependymal giant cell astrocytomas.
C. Infantile spasms.
D. X-linked migrational disorder
D. X-linked migrational disorder
Subcortical band heterotopia is an X-linked migrational disorder that results in a second layer of subcortical gray matter in females. In males, it produces diffuse lissencephaly. Infantile spasms are characteristic of West Syndrome. Subependymal giant cell astrocytomas are characteristic of Tuberous Sclerosis.
- The MOST common clinical feature of medl al temporal lobe seizures is:
A. Visual aura.
B. Ictal Oral Automatism
C. Ictal bicycling movements
D. Ipsilateral dystonic posturing
B. Ictal Oral Automatism
Oral automatisms are a very common ictal behavior during medial temporal lobe seizures and may consist of lip smacking, chewing, swallowing or tooth-grinding. Bicycling movement of the lower extremities are more commonly seen In complex partial seizures that originate In the frontal lobe, particularly supplementary motor area. Gustatory or olfactory aurus, not visual auras, are commonly seen in medial temporal lobe seizures.
Dystonic posturing, while common in mesial temporal seizures, is reliably contralateral. Mesial temporal seizures may be historically related to febrile convulsions most commonly found In early childhood in up to 67% of people with documented medial temporal lobe epilepsy. Epigastric sensations are frequently reported as auras as well.
- West’s syndrome is BEST characterized by which of the following seizure type :
A. Primary and secondarily generalized
B. Generalized tonic clonic
C. Complex partial
D. Infantile Spasm
E. Atonic
D. Infantile Spasm
West’s syndrome produces seizures n early chilhood and consist of infantile spasm, mental retardation, and hypsarrhytmia (complete disorganization) on EEG. With maturity however, these patients can subsequently develop other seizure types. Classically, west’s syndrome is treated with ACTH rather than antiepileptics. Vigatrabine is one AED with improved control of infantile spasps – results compared to ACTH are mixed.
- Which of the following structures is BEST described as lateral to the hippocampal complex (hippocampus,
subiculum and parahlppccampal gyrus)?
A. Brain stem.
B. Ambient cistern.
C. Posterior cerebral artery.
D. Fusiform gyrus
E. Occulomotor nerve
D. Fusiform gyrus
The fusiform gyrus Is late•al to the hippocampal complex. The fusiform gyrus has a functional role In color processing, face and body recognition, word and number recognition, and within-category linguistic processing.
The brain stem, oculomotor nerve, ambient cistern, and posterior cerebral artery are all In close proximity and are medial to the hippocampal complex. The anatomy of these structures is best described in relationship to the brainstem, specifically the midbrain. The oculomotor nerve exits the brain stem in the interpeduncular cistern and therefore lies anterior and medial to the hippocampal complex. The posterior cerebral arteries arise from the terminal division of the basilar artery above the level of CNIII and can be visualized on the lateral surface of the midbrain as it traverses towards and through the ambient cistern.
