CASE REPORT Stereotactic disconnection of hypothalamic hamartoma to control seizure and behavior disturbance: case report and literature review Antonio Nogueira de Almeida & Erich Talamoni Fonoff & Gerson Ballester & Manoel Jacobsen Teixeira & Raul Marino Jr Received: 18 July 2007 / Revised: 2 January 2008 / Accepted: 11 March 2008 / Published online: 29 April 2008 # Springer-Verlag 2008 Abstract An 18-year-old boy with refractory epilepsy and aggressiveness associated to a hypothalamic hamartoma was submitted to a stereotactically guided lesion by thermocoagulation. The target was based on magnetic resonance (MR) images merged with computed tomogra- phy scan images taken on the day of surgery while patient was on a stereotactic frame. In order to reveal structures not discernible in MR images, the Schaltenbrand digital brain atlas was merged onto the patient’ s images. Target and trajectory of the depth electrode were chosen based on three-dimensional imaging reconstructions. A surgical plan was devised to disconnect the hypothalamic hamartoma from the hypothalamus, medial forebrain bundle, fasciculus princeps, and dorsal longitudinal fasciculus. Our target was placed at the inferior portion of the posterolateral compo- nent of the hamartoma, bordering the normal hypothala- mus. The patient evolved with marked lessening of aggressiveness. Seizure frequency was reduced from several seizures per day to less than one tonic-clonic seizure during sleep per month and only two episodes suggestive of partial complex seizures during daytime. These results have remained consistent over a 24-month postoperative follow-up. Functional neuroanatomy of hy- pothalamic connections involved in seizure propagation and aggressive behavior was reviewed. Keywords Epilepsy . Gelastic seizure . Hypothalamic hamartoma . Radiofrequency lesion . Stereotactic surgery Introduction Hypothalamic hamartomas (HHs) are developmental malfor- mations frequently associated with epileptic and endocrine disorders. Predominant clinical features seem particularly influenced by shape and location of the lesion [2]. Sessile hamartomas displacing the mammillary bodies are usually related to refractory seizures, while pedunculated lesions are more typically found in patients with precocious puberty [16]. The epileptic syndrome related to HHs is characterized by onset in infancy, multiple seizure types, progressive mental deterioration, and aggressive behavior. Medical treatment with antiepileptic drugs is acknowledged as ineffective in halting either seizures or neuropsychological decline. In the 1990s, studies confirming intrinsic epileptogenic activity of HHs formed the rationale for surgical treatment [17, 21]. Although frontotemporal and transcallosal approaches were able to remove HHs, some patients who underwent these procedures later presented deep-seated ischemic injuries and short-term memory disturbances [15, 24,]. Given the risks involved in surgical approaches to the third ventricle by craniotomy, less invasive modalities of treatment have been proposed. Among the most cited alternatives in the literature include destruction of the lesion by thermocoagulation [14, 20, 25], radiosurgery Neurosurg Rev (2008) 31:343–349 DOI 10.1007/s10143-008-0142-8 A. N. de Almeida : E. T. Fonoff : G. Ballester : M. J. Teixeira : R. Marino Jr Departamento de Neurologia, Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil A. N. de Almeida (*) Instituto Neurológico de São Paulo, Rua Maestro Cardim, 808 Liberdade, São Paulo, SP 01323-001, Brazil e-mail: almeidaan@globo.com