Gelastic epilepsy gelastic seizures are frequently

This preview shows page 4 - 6 out of 14 pages.

Gelastic epilepsy Gelastic seizures are frequently caused by hypo- thalamic hamartomas (Engelborghs et al. , 2000). In a series of 9 patients with gelastic seizures, 4 had hypothalamic hamartoma (Striano et al. , 1999). Hypothalamic hamartomas are rare congenital mal- formations and often present as a clinical syn- drome, characterized by pubertas praecox, mental retardation, and gelastic seizures. Later, refractory epilepsy with multiple seizure types develops. Patients with hypothalamic hamartoma may as well have focal epileptiform discharges in the anterior temporal or frontal lobe on ictal electrocortico- graphic recordings but focal cortical resection was shown not to affect seizure frequency (Cascino et al. , 1993). According to depth electrode data show- ing ictal onset from the lesion, seizures seem to
Image of page 4

Subscribe to view the full document.

204 S . ENGELBORGHS ET AL . begin in the intrinsically epileptogenic hamartoma (Munari et al. , 1995 ; Kuzniecky et al. , 1997). Ictal single-photon emission computed tomography per- formed during typical gelastic seizures demonstrat- ed hyperperfusion in the hamartoma and the hypo- thalamic region (Kuzniecky et al. , 1997). More- over, complete surgical extirpation or a gamma knife radiosurgical treatment of the hypothalamic hamartoma results in seizure remission (Kuzniecky et al. , 1997 ; Georgakoulias et al. , 1998 ; Unger et al. , 2000). It therefore seems probable that epilep- tic discharges arise in the hypothalamus and spread via hypothalamic-amygdala connections to pro- duce focal temporal lobe ictal discharges (Saper, 1990 ; Berkovic et al. , 1997b). Rasmussen encephalitis Rasmussen encephalitis is a rare, progressive, neurodegenerative illness of unknown cause that typically affects children in the first decade of life (Rasmussen et al. , 1958). Severe seizures that are refractory to anti-epileptic medication, hemispher- ic atrophy, and dementia are cardinal features of this disease. Rabbits immunized with glutamate receptor subunit 3 (GluR3) protein developed epilepsy and cerebral histopathological changes characteristic of Rasmussen encephalitis (Rogers et al. , 1994). This led to the discovery of anti-GluR3 antibodies in serum of patients with Rasmussen encephalitis (Rogers et al. , 1994). Effectiveness of plasma exchanges or intravenous immunoglobin therapy as treatment of Rasmussen encephalitis was demonstrated in a series of patients (Andrews et al. , 1996 ; Topcu et al. , 1999), which further proves the auto-immune pathogenesis of Ras- mussen encephalitis. Insights gained from the study of Rasmussen encephalitis may help to increase our knowledge about more common forms of epilepsy. Some patients undergoing temporal lobectomy for refrac- tory epilepsy show localized inflammatory histo- pathological changes and increased auto-antibodies in serum (Dambinova et al. , 1997 ; Peltola et al. , 2000) ; whether or not this is caused by an auto- immune pathogenesis remains to be elucidated (McNamara, 1999).
Image of page 5
Image of page 6

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern