Hypothalamic hamartomas (HH) are rare (1:200,000), nonneoplastic heterotopic congenital malformations formed by neurons and glial cells located close to the posterior hypothalamus, tuber cinereum, or mammillary bodies [1]. The condition was first described in 1873 as a seizure presenting with laughter [2]. Later, Daly and Mulder named this condition ‘‘gelastic epilepsy’’ [3]. Gelastic seizures, central precocious puberty, and cognitive impairment are the predominant manifestations of HH in infancy [4]. The typical MRI features of HH are isoor hypo-intensity on T1weighted images and isoor slight hyper-intensity on T2-weighted images. A lack of contrast enhancement in the tuber cinereum region is valuable for radiological diagnosis to distinguish tumors from other lesions in this field, such as third-ventricular ependymomas, hypothalamic astrocytomas, germ cell tumors, Langerhans cell histiocytosis, and papillomas. Our patient was diagnosed with HH due to the similarity with previous case reports. The electroencephalogram showed interictal focal (mostly right frontal and temporal) paroxysmal activity (more frequently slow spike-andwave complexes) consistent with HH lateralization. Recent reports have demonstrated the intrinsic epileptogenicity of HH. The mechanism of gelastic epilepsy may be the spontaneous firing of gamma-aminobutyric acid (GABA)-ergic small HH neurons, which project synaptic connections onto the larger adjacent pyramidal-like HH neurons. The combination of these neurons acts as a pacemaker that synchronizes the numerous output neurons to mediate seizure activity in the brain, and this action results in the observed clinical symptoms. This groupof lesionshas been classifiedbyDelalandeas I through IV, based onmorphology onMRI [5]. Type I has a horizontal orientation and may be lateralized to one side. Type II has a vertical orientation and an intraventricular location. Type III is a combination of types I and IIwith a vertical plane of attachmentwithin the ventricle and a horizontal plane of attachment on the underside of the hypothalamus. Type IV is a giant hamartoma. In our patient, the lesion was located in its entirety in the third ventricle (Fig. 2 of Images in Neuroscience: Question) and was thus classified as type II. Due to the insufficient number of clinical reports, there is no consensus regarding the various therapeutic options. Despite the use of higher doses and several combinations of antiepileptic drugs, freedom from seizures or good seizure control is rarely achieved in HH patients [6]. At present, surgical resection, stereotactic endoscopic disconnection, Gamma Knife radiosurgery (Elekta AB, Stockholm, Sweden), and radiofrequency thermocoagulation appear to be useful and safe approaches, particularly for the treatment of small HH [7–9]. In our patient, numerous antiepileptic drugs were utilized in various combinations for approximately 4 years; however, none of these treatments exhibited any efficacy. Subsequently, the patient underwent Gamma Knife radiosurgery and long-term follow-up. Further studies are needed to assess the prognosis.