Comprehensive review of status gelasticus: Diagnostic challenges and therapeutic insights

Status gelasticus is a rare form of status epilepticus characterized by prolonged and/or clustered gelastic seizures. The review encompasses an analysis of cases reported in the literature, focusing on causes, clinical-electroencephalographic features, and therapeutic interventions. The study reveals the challenges in defining and understanding status gelasticus due to its diverse etiologies and limited reported cases. The association with hypothalamic hamartomas and other brain abnormalities underscores the importance of thorough evaluations. The review also discusses new treatments, including medications and less invasive surgeries. While progress has been made, the study points out challenges in diagnosing and managing this complex condition, highlighting the importance of ongoing research.

Multimodal Approach for the Treatment of Complex Hypothalamic Hamartomas

Hypothalamic hamartomas (HHs) are rare congenital lesions formed by heterotopic neuronal and glial cells attached to the mammillary bodies, tuber cinereum, and hypothalamus.They often present with an intractable epilepsy typically characterized by gelastic seizures but commonly associated with other types of refractory seizures. The clinical course is progressive in most of the cases, starting with gelastic seizures in infancy and deteriorating into complex seizure disorders that result in catastrophic epilepsy associated with cognitive decline and behavioral disturbances.Hamartomas are known to be intrinsically epileptogenic and the site of origin for the gelastic seizures. As antiepileptic drugs are typically ineffective in controlling HH-related epilepsy, different surgical options have been proposed as a treatment to achieve seizure control. Resection or complete disconnection of the hamartoma from the mammillothalamic tract has proved to achieve a long-lasting control of the epileptic syndrome.Usually, symptoms and their severity are typically related to the size, localization, and type of attachment. Precocious puberty appears mostly in the pedunculated type, while epileptic syndrome and behavioral decline are frequently related to the sessile type. For this reason, different classifications of HHs have been developed based on their size, extension, and type of attachment to the hypothalamus.The bigger and more complex hypothalamic hamartomas typically present with severe refractory epilepsy, behavioral disturbances, and progressive cognitive decline posing a formidable challenge for the control of these symptoms.We present here our experience with the multimodal treatment for complex hypothalamic hamartomas. After an in-depth review of the literature, we systematize our approach for the different types of hypothalamic hamartomas.

Ictal semiology of gelastic seizures

Gelastic seizures are rare epileptic manifestations characterized by laughter or a smile. The main etiology is represented by hypothalamic hamartoma, but also focal localization of the epileptogenic zone is described. We reviewed a group of patients with gelastic seizures to describe the semiology and to establish any difference related to diverse epilepsy etiologies. Thirty-five seizures from 16 patients (6 females) were reviewed. The study confirms that hypothalamic hamartoma is the more frequent etiology associated with gelastic seizures. Laughter represented the majority of gelastic ictal signs, while the ictal smile was less frequent. In 87.5% of patients, the manifestation of laughter or smile was the only ictal phenomenon, or the first and the most important clinical sign. Interestingly, it has been observed that patients with a lesion localized in the hypothalamic region had more frequently laughter with emotional involvement and that laughter was the only manifestation of the seizure. On the contrary, patients with lesions localized outside the hypothalamic region had more often seizures with laugh without emotional involvement, resembling a more mechanical action, and associated with other semeiological signs. It, therefore, seems possible to assume that the emotional involvement and the expression of mirth during the seizure, especially in children, are more frequently associated with hypothalamic hamartoma. On the contrary, when the semiology includes less conveyed emotion similar to a mechanical action and other symptoms, an extra hypothalamic localization should be considered.

MR imaging of hypothalamic hamartoma in a patient with gelastic seizures

Hypothalamic hamartomas (HHs) are non-neoplastic malformations that occur in the region of the hypothalamus. HH is the leading cause of gelastic seizures in children and adolescents, where laughing is characteristically manifested. However, these patients can also experience different forms of complex or generalized tonic-clonic seizures that can obscure the diagnosis of HHs. We present a case of a 10 year-old boy that experienced several seizure types, but was subsequently diagnosed with HH after MR imaging was performed. This case highlights the complementary role of MR imaging in ascertaining seizure etiololgy when the clinical history and EEG findings are non-specific. The importance of early diagnosis with MR imaging is further underscored by the fact that patients diagnosed with HH usually develop drug resistance towards antiepileptic drugs, mandating neurosurgical assessment and intervention.

Gelastic seizures and the hypothalamic hamartoma syndrome: Epileptogenesis beyond the lesion?

The clinicoradiologic syndrome of hypothalamic hamartoma (HH) manifests with a variety of symptoms, including pharmacoresistant epilepsy with multiple seizure types, precocious puberty, behavioral disturbances, and cognitive impairment. Gelastic seizures are an early marker of epilepsy with HH in most of the cases. Despite a high variability, two major epilepsy phenotypes can be distinguished, based on electroclinical features: (i) focal seizures with epigastric or déjà-vu aura, loss of consciousness, and oroalimentary or gestural automatisms suggestive of temporal lobe involvement; and (ii) motor seizures with tonic, atonic, myoclonic, or versive phenomena, suggesting frontoparietal network involvement, with possible evolution toward an epileptic encephalopathy. The underlying physiopathologic mechanisms are not completely elucidated. The well-known intrinsic epileptogenicity of the HH represents the rationale for direct HH-aiming surgical procedures, with variable success in achieving seizure freedom. The concept of kindling-like secondary epileptogenesis has been suggested as a possible putative mechanism since the very beginnings of the hamartocentric era. Accordingly, a cortical area with enhanced epileptogenic properties due to an independent stage of secondary epileptogenesis would be responsible for seizures persisting after hamartoma ablation. However, recent intracerebral stereotactic EEG (SEEG) explorations demonstrated more complex, both reciprocal and hierarchical, relationships within the hypothalamo-cortical epileptogenic networks. Network formation may be due to either secondary epileptogenesis or widespread epileptogenicity present at the outset. A short time window from epilepsy onset to surgery seems to be crucial to cure epilepsy by direct surgery addressing a hamartoma. SEEG exploration may be reasonably proposed in cases where clinical data suggest an extension of the epileptogenic zone outside the limits of the HH, especially in focal seizures with impaired awareness and absence of gelastic seizures, or after a failure of the direct HH-aiming procedure.

Staged Magnetic Resonance-Guided Laser Interstitial Thermal Therapy for Hypothalamic Hamartoma: Analysis of Ablation Volumes and Morphological Considerations

BACKGROUND

Hypothalamic hamartomas (HH) are a challenging pathology that cause gelastic seizures. Magnetic Resonance Imaging-guided Laser Interstitial Thermal Therapy (MRgLITT) offers a safe and effective treatment for HHs via a minimally invasive technique.

OBJECTIVE

To determine how clinical outcome correlates to residual tumor volume and surgical strategy by analyzing radiographic data and reconstructing volumetric imaging.

METHODS

Clinical and radiographic information of 58 pediatric patients who underwent MRgLITT for HH with at least 6 mo of follow-up were retrospectively reviewed. MR imaging was volumetrically reconstructed to analyze the impact of hamartoma and ablation volumes on outcome. Primary outcome measure was freedom from gelastic seizures.

RESULTS

Eighty-one percent of patients were completely free of gelastic seizures at last follow-up; of 22 patients with secondary nongelastic epilepsy, 15 were free of additional seizures. Postoperative complication rate was low. There was no significant difference in gelastic seizure outcome related to pre- or postoperative hamartoma size. Residual hamartoma percentage in those free of gelastic seizures was 43% compared to 71% in those with continued seizures (P = .021). Larger hamartomas required multiple ablations to achieve seizure freedom.

CONCLUSION

This large series of patients confirms the safety and efficacy of MRgLITT for pediatric HH and describes morphological considerations that predict success. Our data suggest that complete ablation of the lesion is not necessary, and that the focus should be on appropriate disconnection of the epileptogenic network. We have found that a staged approach to hamartoma ablation allows adequate disconnection of the hamartoma while mitigating risk to surrounding structures.

Ecstatic and gelastic seizures related to the hypothalamus

Ecstatic seizures constitute a rare form of epilepsy, and the semiology is diverse. Previously, brain areas including the temporal lobe and the insula have been identified to be involved in clinical expression. The aim of this report is to review changes in ecstatic seizures in a patient before and after operation for a hypothalamic hamartoma, and to scrutinize the relation to gelastic seizures. In this case, the ecstatic seizures disappeared after surgery of the hamartoma but reappeared eleven years later. Clinical information was retrospectively obtained from medical records, interviews, and a questionnaire covering seizure semiology that pertained to ecstatic and gelastic seizures. Our findings imply a possible connection between gelastic and ecstatic seizures, originating from a hypothalamic hamartoma. To our knowledge, this location has not previously been described in ecstatic seizures. Gelastic seizures may in this case be associated with ecstatic seizures. We speculate that patients with ecstatic seizures may have an ictal activation of neuronal networks that involve the insula. Our case may add information to the knowledge concerning ecstatic seizures.

A Simple Technique for Endoscopic Hypothalamic Hamartoma Disconnection in Refractory Epilepsy: 2-Dimensional Operative Video

Hypothalamic hamartomas often cause refractory epilepsy, best controlled with surgery. A transcallosal interforniceal approach provides good outcomes although it has resulted in some complications including fornix lesions with transitory and permanent memory losses.1-2 Endoscopic disconnection is less invasive, avoids interhemispheric approach, callosotomy and fornix as well as propagation of epileptic discharges.3,4 Laser disconnection does not allow objective measurement of the vaporized tissue and can cause significant hypothalamic edema. We demonstrate a simple hypothalamic disconnection endoscopy technique using the VarioGuide frameless stereotactic system (Brainlab, Germany), bipolar coagulation electrode (Karl Storz, Germany), and 3-French Fogarty catheter (Edwards Lifesciences, USA).  We present a 12-yr-old right-handed girl who developed normally until 4 yr old when gelastic seizures began. Antiepileptic drugs and gamma knife radiosurgery did not control the seizures. Magnetic resonance imaging showed a nodular 13 mm left hypothalamic mass protruding into the third ventricle. The patient consented to surgery.  We used a rigid 30° 6-mm neuroendoscope (Aesculap, Germany) with VarioGuide to reach the ventricle. After visualizing the foramen of Monro, the bipolar coagulation electrode perforated holes along the hamartoma/hypothalamus interface. The Fogarty balloon catheter was inserted into each hole and gently inflated to connect the holes and disconnect the mass from the hypothalamus.  The patient's postsurgical recovery was excellent, presenting intact short- and long-term memory without neurological deficit or endocrine complications. She continues seizure-free 2 yr after surgery. We have successfully used this technique in 4 more cases and, if results continue to be good, will consider it a useful tool for these infrequent malformations.

Hypothalamic hamartomas: A comprehensive review of the literature - Part 1: Neurobiological features, clinical presentations and advancements in diagnostic tools

Hypothalamic hamartomas (HH) are rare, non-neoplastic heterotopic tissues which contains normal neurons and glia including oligodendrocytes and fibrillary astrocytes but in an abnormal distribution. They arise from the floor of the third ventricle, tuber cinereum, or mammillary bodies. Estimated incidence ranges from 1 in 50,000-1 in 1,000,000. Hypothalamic hamartomas are associated with different clinical presentations including various types of seizures, most characteristically; the gelastic seizures, precocious puberty, cognitive impairment, and behavioral changes. In this review, the authors discuss advancements in different diagnostic elements of hypothalamic hamartoma; including clinical features, EEG findings, and neuroimaging techniques. Moreover, different classifications described in the literature will be discussed.

Ecstatic and gelastic seizures relate to the hypothalamus

Ecstatic seizures constitute a rare form of epilepsy, and the semiology is diverse. Previously, brain areas including the temporal lobe and the insula have been identified to be involved in clinical expression. The aim of this report is to review changes in ecstatic seizures in a patient before and after operation of a hypothalamic hamartoma, and to scrutinize the relation to gelastic seizures. In this case, the ecstatic seizures disappeared after surgery of the hamartoma but reappeared eleven years later. Clinical information was retrospectively obtained from medical records, interviews, and a questionnaire covering seizure semiology that pertained to ecstatic and gelastic seizures. Our findings imply a possible connection between gelastic and ecstatic seizures, originating from a hypothalamic hamartoma. To our knowledge, this location has not previously been described in ecstatic seizures. Gelastic seizures may in this case were associated with ecstatic seizures. We speclate patients with ecstatic seizures may have an ictal activation of neuronal networks that involves the insula. Our case may add information to the growing knowledge concerning ecstatic seizures.

Gelastic seizures not associated with hypothalamic hamartoma: A long-term follow-up study

OBJECTIVE

The objective of the study was to describe the electroclinical features, seizure semiology, and the long-term evolution of gelastic seizures (GS) not associated with hypothalamic hamartoma (HH).

METHODS

We reviewed video-electroencephalogram (video-EEG) recordings from pediatric patients with GS without HH admitted to 14 Italian epilepsy centers from 1994 to 2013. We collected information about age at onset, seizures semiology, EEG and magnetic resonance imaging (MRI) findings, treatment, and clinical outcome in terms of seizure control after a long-term follow-up.

RESULTS

A total of 30 pediatric patients were stratified into two groups according to neuroimaging findings: group 1 including 19 children (63.3%) with unremarkable neuroimaging and group 2 including 11 children with structural brain abnormalities (36.7%). At the follow-up, patients of group 1 showed better clinical outcome both in terms of seizure control and use of AED polytherapy. Our patients showed remarkable clinical heterogeneity, including seizure semiology and epilepsy severity. Electroencephalogram recordings showed abnormalities mainly in the frontal, temporal, and frontotemporal regions without relevant differences between the two groups. Overall, carbamazepine showed good efficacy to control GS.

CONCLUSIONS

Patients with nonlesional GS have a more favorable outcome with better drug response, less need of polytherapy, and good long-term prognosis, both in terms of seizure control and EEG findings.

Hypothalamic hamartoma presenting with infantile spasms

BACKGROUND

Hypothalamic hamartomas (HH) generally present with gelastic seizures. It is very unusual for a pediatric patient with HH to present with infantile spasms (IS).

CASE PRESENTATION

Here we present a 6-month-old boy diagnosed with IS whose brain magnetic resonance imaging (MRI) showed an 18 × 18 × 16 mm mass in the hypothalamus. His seizures did not respond to antiepileptic treatment with vigabatrin and valproic acid. He had disconnective surgery for HH. Immediately postoperatively, his seizures subsided and he has now been seizure-free for 2 years.

CONCLUSION

Although hypothalamic hamartomas generally present with gelastic seizures, they should also be considered in the differential diagnosis of infantile spasms.

A case of pure gelastic seizures due to hypothalamic hamartoma with a benign course

Hypothalamic hamartoma is a potentially complex entity with diverse clinical manifestations. We report a case of gelastic seizures associated with a hypothalamic hamartoma, which followed a benign course. A 31-year-old woman with episodes of laughter was referred for diagnostic evaluation. Her initial MRI and EEG were reported as normal. However, her episodes of laughter were typical of gelastic seizures from history and video review. Repeat MRI revealed a small HH. She declined any medical treatment and was medication free until last follow-up. This benign course of HH-associated epilepsy, not necessitating treatment, to our knowledge, has not been previously reported.

Successful surgical management of New Onset Refractory Status Epilepticus (NORSE) presenting with gelastic seizures in a 3 year old girl

Gelastic seizures (GS) are typically associated with hypothalamic hamartomas and present during childhood. However it is now known that GS can be found in focal epilepsies arising from other regions in the brain, including mesial and neocortical frontal, temporal and parietal regions.

GS have rarely been described as the presenting manifestation of New Onset Refractory Status Epilepticus (NORSE). In this article we describe a previously healthy 3-year-old who presented with an explosive onset of GS that were refractory to multiple anti-seizure medications. These seizures arose from the right frontal region. An extensive metabolic and immunological evaluation was negative. Her brain magnetic resonance imaging (MRI) was negative, however the Positron Emission Tomography (PET) scan showed a hypermetabolic region in the right frontal inferior gyrus.

She underwent a depth electrode evaluation that revealed a widespread irritative zone involving the PET “lesion” as well as mesial and neocortical regions in the right frontal lobe. The seizure onset zone was widespread and non-localizable. However the GS were associated with a clear ictal epileptiform discharge on invasive EEG arising from the depth of the superior frontal gyrus, which was not overlapping with the PET hypermetabolic region. She underwent a right frontal lobectomy sparing the primary motor region in the pre-central gyrus. She has remained seizure free for 15 months since. The pathological analysis showed focal cortical dysplasia type II in the region of the PET scan hypermetabolism. This case expands the clinical spectrum of GS to include cases of NORSE. Additionally the case highlights the role of resective surgery in GS presenting as NORSE and the potentially excellent outcome that can be achieved by early intervention.

Pure endoscopic management of epileptogenic hypothalamic hamartomas

Hypothalamic hamartomas (HH) are rare congenital malformations located in the region of the tuber cinereum and third ventricle. Their usual clinical presentation is characterized by gelastic/dacrystic seizures which often become pharmaco-resistant and progress to secondary focal/generalized intractable epilepsy causing mostly in children cognitive and behavioral problems (particularly in cases of progressive epileptic encephalopathy) and precocious puberty. Whereas gelastic seizures can be surgically controlled either by resection of the lesion or disconnection (tissue-destructive) procedures, aimed at functionally prevent the spreading of the epileptic burst; generalized seizures tend to respond better to HH excision rather than isolated neocortical resections, which generally fail to control them. Prospective analysis of 14 consecutive patients harboring HH treated in an 8-year period; 12 patients had unilateral and two bilateral HH. All patients were managed by pure endoscopic excision of the HH. The mean operative time was 48 min and mean hospital stay was 2 days; perioperative blood loss was negligible in all cases. Two patients showed a transient diabetes insipidus (DI); no transient or permanent postoperative neurological deficit or memory impairment was recorded. Complete HH excision was achieved in 10/14 patients. At a mean follow-up of 48 months, no wound infection, meningitis, postoperative hydrocephalus, and/or mortality were recorded in this series of patients. Eight patients became seizure free (Engel class I), 2 other experienced worthwhile improvement of disabling seizures (Engel class II); 2 patients were cured from gelastic attacks while still experiencing focal dyscognitive seizures; and 2, having bilateral HH (both undergoing unilateral HH excision), did not experience significant improvement and required later on a temporal lobectomy coupled to amygdalohyppocampectomy. Overall, the followings resulted to be predictive factors for better outcomes in terms of seizure control: (1) cases of unilateral, Delalande class B, HH, (2) shorter history of epilepsy. Endoscopic resection of HH proved, in our series, to be effective in achieving complete control or in reducing the frequency of seizures. Furthermore, this approach has confirmed its minimally invasive nature with a very low morbidity rate: of note, it allowed to better preserve short-term memory and hypothalamic function.

Clinical features and postoperative seizure outcome in patients with drug-resistant gelastic seizures without hypothalamic hamartoma

OBJECTIVES

The objective of this study was to describe the clinical characteristics and surgical outcome in patients with gelastic seizures without hypothalamic hamartoma.

METHODS

We retrospectively reviewed all the video-EEG reports over a 5-year period (2007-2011) for the occurrence of the terms "laugh" or "giggle" in the text body. All the patients with at least one documented gelastic seizure at the epilepsy monitoring unit were studied. In patients who underwent epilepsy surgery, seizure outcomes were analyzed.

RESULTS

Sixteen patients (10 females and 6 males) with a mean age of 46.3years were studied. Seven patients had invasive intracranial EEG recordings. Seizure onset zone was in a temporal lobe in four patients and the frontal lobe in one patient. Two patients did not have gelastic seizures during their intracranial EEG monitoring. Nine patients underwent resective epilepsy surgery for their seizures. Six patients (67%) were seizure-free after surgery.

CONCLUSION

In adult patients, gelastic seizures can be seen in patients with focal epilepsy without hypothalamic hamartoma. Nonhypothalamic hamartoma gelastic seizures originating from the temporal lobe can be amenable to surgery.

Neurological complications after gamma-knife radiosurgery for hypothalamic hamartoma

BACKGROUND

The Gamma-knife technique is a safe and effective option for the treatment of hypothalamic hamartomas that produce epileptic seizures refractory to medical treatment and/or serious behavioral disorders. After this type of radiosurgery, an adequate symptomatic control is normally achieved, with notable decrease or even disappearance of the seizures. Radiological changes, such as a decrease in the size of the tumor or adjacent edema secondary to non-necrotizing radioinduced inflammatory reaction are unusual consequences. Side effects and neurological complications are also rare events.

CASE PRESENTATION

This report describes an unusual case of complete radiological resolution of a hypothalamic hamartoma as well as neurological complications after Gamma-knife surgery (receiving 13 Gy to the 85% isodose line, 1 cm(3) of tumor volume) in a 8-year-old boy who suffered from severe refractory seizures. After radiosurgery, the patient experienced a notable improvement in his symptoms, achieving seizure cessation within 3 months. However, 4 months after the procedure he presented drowsiness, fever and decreased level of consciousness due to a direct effect on the hypothalamus with local and regional edema secondary to the radiosurgery that was performed. He was successfully treated with corticosteroids (with a total duration of 11 months), and twelve months after the surgery, complete disappearance of both the nodular lesion and the secondary edema was observed. The patient remains seizure-free in the last 16 months, with remarkable changes in his behavior.

CONCLUSIONS

The present case shows that complete radiological resolution of a hypothalamic hamartoma after Gamma-knife technique is unusual but possible, without long-term neurological consequences. Nevertheless, despite its low incidence, if a patient presents neurological symptoms, primarily during the first year after intervention, possible complications of this type of surgery must be taken into account.

Gap Junctions Contribute to Ictal/Interictal Genesis in Human Hypothalamic Hamartomas

Human hypothalamic hamartoma (HH) is a rare subcortical lesion associated with treatment-resistant epilepsy. Cellular mechanisms responsible for epileptogenesis are unknown. We hypothesized that neuronal gap junctions contribute to epileptogenesis through synchronous activity within the neuron networks in HH tissue. We studied surgically resected HH tissue with Western-blot analysis, immunohistochemistry, electron microscopy, biocytin microinjection of recorded HH neurons, and microelectrode patch clamp recordings with and without pharmacological blockade of gap junctions. Normal human hypothalamus tissue was used as a control. Western blots showed increased expression of both connexin-36 (Cx36) and connexin-43 (Cx43) in HH tissue compared with normal human mammillary body tissue. Immunohistochemistry demonstrated that Cx36 and Cx43 are expressed in HH tissue, but Cx36 was mainly expressed within neuron clusters while Cx43 was mainly expressed outside of neuron clusters. Gap-junction profiles were observed between small HH neurons with electron microscopy. Biocytin injection into single recorded small HH neurons showed labeling of adjacent neurons, which was not observed in the presence of a neuronal gap-junction blocker, mefloquine. Microelectrode field recordings from freshly resected HH slices demonstrated spontaneous ictal/interictal-like discharges in most slices. Bath-application of gap-junction blockers significantly reduced ictal/interictal-like discharges in a concentration-dependent manner, while not affecting the action-potential firing of small gamma-aminobutyric acid (GABA) neurons observed with whole-cell patch-clamp recordings from the same patient's HH tissue. These results suggest that neuronal gap junctions between small GABAergic HH neurons participate in the genesis of epileptic-like discharges. Blockade of gap junctions may be a new therapeutic strategy for controlling seizure activity in HH patients.

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Neuronal-type functional gap junctions are present in HH tissue.

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Expression of neuronal-type gap junctions is more abundant in HH tissue relative to normal hypothalamus (mammillary body).

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In HH slices, pharmacological block of neuronal-type gap junctions significantly reduces seizure-like discharges.

This paper evaluates the role that gap junctions contribute to seizure activity utilized human hypothalamic hamartoma (HH) tissue after surgical resection. We find that 1) gap junctions are present in HH tissue, 2) gap junctions are more abundant in HH tissue relative to normal hypothalamus (mammillary body), and 3) pharmacological blockade of gap junctions in freshly-resected HH tissue slices can decrease the seizure-like discharges. These results provide evidence that gap junctions participate in the generation of seizures from HH tissue and suggest further research into the possibility that gap junction blocking medications may improve seizures in patients with HH.

Gelastic epilepsy: Beyond hypothalamic hamartomas

Gelastic epilepsy or laughing seizures have been historically related to children with hypothalamic hamartomas. We report three adult patients who had gelastic epilepsy, defined as the presence of seizures with a prominent laugh component, including brain imaging, surface/invasive electroencephalography, positron emission tomography, and medical/surgical outcomes. None of the patients had hamartoma or other hypothalamic lesion. Two patients were classified as having refractory epilepsy (one had biopsy-proven neurocysticercosis and the other one hippocampal sclerosis and temporal cortical dysplasia). The third patient had no lesion on MRI and had complete control with carbamazepine. Both lesional patients underwent resective surgery, one with complete seizure control and the other one with poor outcome. Although hypothalamic hamartomas should always be ruled out in patients with gelastic epilepsy, laughing seizures can also arise from frontal and temporal lobe foci, which can be surgically removed. In addition, we present the first case of gelastic epilepsy due to neurocysticercosis.

Psychogenic nonepileptic seizures mimicking gelastic seizures: A description of two cases

Psychogenic nonepileptic seizures (PNES) are sudden, involuntary seizure-like attacks that, unlike epileptic seizures, are not related to electrographic ictal discharges and are psychological in nature. Psychogenic nonepileptic seizures presenting symptoms mimic a wide array of nervous system dysfunctions, as they involve changes in behavior, motor activity, sensation, cognitive, and autonomic functions. Spontaneous paroxysms of laughing resembling gelastic seizure have only exceptionally been reported as main symptom of PNES. Here, we describe the cases of two patients with a prolonged history of laughter attacks mistaken for epilepsy and unresponsive to AED treatment. Brain MRI and interictal EEG were unremarkable. Video-EEG monitoring allowed us to document the spontaneous and suggestion-induced habitual episodes that were then diagnosed as PNES.

Mechanisms of intrinsic epileptogenesis in human gelastic seizures with hypothalamic hamartoma

Human hypothalamic hamartoma (HH) is a rare developmental malformation often characterized by gelastic seizures, which are refractory to medical therapy. Ictal EEG recordings from the HH have demonstrated that the epileptic source of gelastic seizures lies within the HH lesion itself. Recent advances in surgical techniques targeting HH have led to dramatic improvements in seizure control, which further supports the hypothesis that gelastic seizures originate within the HH. However, the basic cellular and molecular mechanisms of epileptogenesis in this subcortical lesion are poorly understood. Since 2003, Barrow Neurological Institute has maintained a multidisciplinary clinical program to evaluate and treat patients with HH. This program has provided a unique opportunity to investigate the basic mechanisms of epileptogenesis using surgically resected HH tissue. The first report on the electrophysiological properties of HH neurons was published in 2005. Since then, ongoing research has provided additional insights into the mechanisms by which HH generate seizure activity. In this review, we summarize this progress and propose a cellular model that suggests that GABA-mediated excitation contributes to epileptogenesis in HH lesions.

Gelastic epilepsy without hypothalamic hamartoma: three additional cases

We describe three children with gelastic seizures without hypothalamic hamartoma whose seizures were characterized by typical laughing attacks associated or not with other seizure types. Ictal/interictal EEG and magnetic resonance imaging were performed. All three subjects showed a good response to carbamazepine therapy with complete seizure control in addition to a benign clinical and cognitive outcome. These three cases confirm that gelastic epilepsy without hypothalamic hamartoma, both in cryptogenic or symptomatic patients (one child showed a dysplastic right parietotemporal lesion), usually has a more benign natural history, and carbamazepine seems to be the most efficacious therapy to obtain both immediate and long-term seizure control. These findings need to be confirmed in a larger sample of children affected by gelastic epilepsy without hypothalamic hamartoma.

Different localizations underlying cortical gelastic epilepsy: case series and review of literature

BACKGROUND

Gelastic seizures (GS) are classically observed with hypothalamic hamartomas but they can also be associated with cortical epileptogenic foci.

OBJECTIVE

To study the different cortical localizations associated with GS.

METHODS

We reviewed the data from all patients with cortical GS investigated in our epilepsy unit from 1974 to 2012 and in the literature from 1956 to 2013.

RESULTS

Sixteen cases were identified in our database and 77 in the literature. Investigations provided confident focus localization in 9 and 18, respectively. In our series, the identified foci were located in the mesial temporal structures (2 left, 1 right), lateral temporal cortex (1 right), superior frontal gyrus (1 left), and operculoinsular region [3 right (orbitofrontal or frontal operculum extending into the anterior insula) and 1 left (frontal operculum extending into the anterior insula)]. In the literature, the identified foci (13 right/5 left) were located in the temporal lobe of 4 (1 right inferior, 1 right medial and inferior, 1 right posterior middle, inferior extending posteriorly to the lingual gyrus, and 1 left middle, inferior, and medial), in the frontal lobe of 12 [10 (6 right/4 left) medial (i.e., superior, medial frontal, and/or anterior cingulate gyri), 1 lateral (right anterior inferior frontal gyrus), and 1 right medioposterior orbitofrontal cortex] and in the parietal lobe of 2 (1 left superior parietal lobule and 1 right parietal operculum) patients.

CONCLUSION

Ictal laughter is a poorly lateralizing and localizing feature as it may be encountered in patients with a focus in the left or right frontal, temporal, parietal, or insular lobe.

Clinical characteristics and long-term outcome of surgery for hypothalamic hamartoma in children with refractory epilepsy

CONTEXT

Hypothalamic hamartomas (HH) are ectopic masses of neuronal and glial tissue most commonly presenting with medically refractory gelastic seizures with evolution to other seizure types. They are also associated with cognitive and behavioral problems to varying extent. Surgery has been found to improve quality of life in more than 50% of patients.

AIM

To evaluate the clinical characteristics and long-term outcome of surgery in children with HH and refractory epilepsy.

MATERIALS AND METHODS

A retrospective analysis of presurgical, surgical, and postsurgical data of six children who underwent surgery for HH and had at least 3 years follow-up was performed.

RESULTS

SIX CHILDREN (MALE: female = 5:1) aged 3-16 years (at the time of surgery) underwent surgical resection of HH for refractory epilepsy. At last follow-up (range 3-9 years), three children were in Engel's class I, two in Class II, and one in class III outcome. Significant improvement in behavior, quality of life was noted in four children; while the change in intelligence quotient (IQ) was marginal.

CONCLUSIONS

Medically refractory epilepsy associated with behavioral and cognitive dysfunction is the most common presentation of HH. Open surgical resection is safe with favorable outcome of epilepsy in 50% with significant improvement in behavior and marginal change in cognitive functions.