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- MATERIALS AND METHODS
Summary: Purpose: Hamartomas of the hypothalamus (HH) cause an uncommon and unusual epilepsy syndrome. The condition is recognized to affect children, but the presentation in adults is not well understood. We present 19 children and adult patients with HH, including three patients whose epilepsy began in adult life. The patterns of clinical presentation, evolution of the epilepsy from childhood to adult life, and electroclinical diagnostic features are presented.
Methods: Nineteen patients, both children and adults with HH and epilepsy, were evaluated clinically, with EEG, video-EEG, and magnetic resonance imaging (MRI) scanning. Seven patients underwent surgical resection of the hamartoma. Stereotactic thermocoagulation of the hamartoma was performed in two patients.
Results: Gelastic seizures occurred at onset of epilepsy in 15 of 16 early-onset cases. Subsequently, multiple seizures types occurred, which then evolved to mainly partial epilepsy with tonic or complex partial seizures (five of eight adults), or became entrenched symptomatic generalized epilepsy with atypical absences, drop attacks, and secondarily generalized seizures, and cognitive impairment (three of eight adults). In the adult-onset patients, gelastic seizures were not prominent, the epilepsy was milder, and they functioned normally. Stereotactic thermocoagulation of the hamartoma resulted in improvement in seizure control in two patients.
Conclusions: Gelastic seizures are not a prominent feature of epilepsy in adult patients with HH. The epilepsy associated with HH, although severe at onset, can evolve into a milder syndrome in later life. For less severely affected patients, minimally invasive alternatives to the traditionally difficult open surgical treatment should be considered.
Hamartomas of the hypothalamus (HHs) cause an epilepsy syndrome associated with gelastic seizures, precocious puberty (PP), and multiple seizure types (1,2). It is generally recognized to begin in childhood. The hamartomas are intrinsically epileptogenic (3,4), and ablation of the hamartoma by surgical and other means has been shown to cause seizure remission (5,6).
The pathophysiology of the epilepsy associated with the hamartoma is yet to be elucidated. It has been demonstrated by depth electrode studies that the gelastic seizures arise from the hamartoma (3,7). Ictal single-photon emission computed tomography (SPECT) studies have shown increased blood flow in the hamartoma during gelastic seizures (4). The origin of the other seizure types that occur is less clear. However, because all seizure types are reduced by the ablation of the lesion, the hamartoma clearly also has a fundamental role in the genesis of all the seizures.
In children, HHs can be associated with a devastating epilepsy syndrome, often compounded by additional severe behavioral problems and cognitive impairment. PP occurs in up to a third of patients (2). This is, however, only one end of a spectrum. The onset in adults is not well studied, and the milder presentation has been only recently recognized (8,9). We present the clinical and electroencephalographic features of 19 patients, both children and adults with HHs, who demonstrated a wider spectrum of disease, and we emphasize the clinical features noted in adult patients.
MATERIALS AND METHODS
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- MATERIALS AND METHODS
Nineteen patients were assessed at King's College and the Maudsley Hospital, London between 1991 and 2001. Their clinical data, scalp EEG recordings, and where available, video-EEG and depth electrode EEG recordings were reviewed. Magnetic resonance imaging (MRI) scans were evaluated for signal characteristics, size, location, and the nature of the attachment of the hamartoma to the hypothalamus. The relation of the hamartoma to the hypothalamus was classified as pedunculated (when the hamartoma was attached to the hypothalamus by a stalk) and sessile (broad attachment to hypothalamus) (10). Further they also were classified along the lines suggested by Arita et al. (11) as “parahypothalamic type” and “intrahypothalamic type.” Clinical correlation between the HH types and the epilepsy features was performed by using the Arita classification. Seven patients underwent surgical removal of the hamartoma, and these specimens were evaluated histopathologically. Two patients underwent stereotactic thermocoagulation of the HHs.