Hypothalamic hamartomas and gelastic epilepsy: a spectroscopic study

In vivo magnetic resonance spectroscopy for the differential diagnosis of a cerebral mass in a boy with precocious puberty: a case report and review of the literature

PURPOSE

To highlight the role of in vivo magnetic resonance spectroscopy (MRS) as a non-invasive tool that can clarify the etiology of sellar tumors by presenting the case of a boy with central precocious puberty (CPP) and to review the current literature.

METHODS

A 4-year-old boy was admitted to our hospital due to repeated episodes of focal and gelastic seizures in the previous year. Clinical examination (testicular volume 4-5 ml bilaterally, penile length of 7.5 cm, and absence of axillary or pubic hair) and laboratory tests (FSH, LH, and testosterone) were indicative of CPP. The combination of gelastic seizures with CPP in a 4-year-old boy raised the suspicion of hypothalamic hamartoma (HH). Brain MRI revealed a lobular mass in the suprasellar-hypothalamic region. The differential diagnosis included glioma, HH, and craniopharyngioma. To further investigate the CNS mass, an in vivo brain MRS was performed.

RESULTS

Οn conventional MRI, the mass demonstrated isointensity to gray matter on T1 weighted images but slight hyperintensity on T2-weighted images. It did not show restricted diffusion or contrast enhancement. On MRS, it showed reduced N-acetyl aspartate (NAA) and slightly elevated myoinositol (MI) compared with values in normal deep gray matter. The MRS spectrum, in combination with the conventional MRI findings, were consistent with the diagnosis of a HH.

CONCLUSION

MRS is a state-of-the-art, non-invasive imaging technique that compares the chemical composition of normal tissue to that of abnormal regions by juxtaposing the frequency of measured metabolites. MRS, in combination with clinical evaluation and classic MRI, can provide identification of CNS masses, thus eliminating the need for an invasive biopsy.

Pathological laughter as prodromal manifestation of transient ischemic attacks--case report and brief review

BACKGROUND

Based on a case report, the authors reviewed the data about involuntary emotional expression disorder (IEED). IEED includes the syndromes of pathological laughing and crying (PLC) and emotional lability (EL). PLC is a rare disorder of emotional expression characterized by relatively uncontrollable episodes of laughter and crying or both that do not have an apparent motivating stimulus.

CASE PRESENTATION

Authors report the case of a 59-year-old man who presented with recurrent episodes of PLC of approximately 2 min duration, consisting of accelerated breathing, emission of guttural, snoring sounds, frowning of the eyebrows, followed by laughter accompanied by motor restlessness of all four limbs. PLC episodes preceded left carotid transient ischemic attacks (TIA's) manifested by reversible aphasia and right hemiparesis. Electroencephalography performed during PLC episodes revealed no spike-wave activity. Brain magnetic resonance imaging showed lacunar infarcts in the left lenticulo-capsulo-thalamic area and multiple round lesions in the cortical-subcortical and in the deep white matter of frontal-parietal-occipital lobes bilaterally, with T2 hyperintensity, T1 isointensity and no diffusion changes. The episodes were interpreted as transient ischemic attacks although gelastic seizures could not be excluded. The etiological investigations revealed unstable plaques on the left carotid artery bulb and the aortic arch and a degenerative mitral valve stenosis. The patient was treated first with antiplatelet therapy and antiepileptic drugs but PLC stopped only after anticoagulation was started. During follow-up the patient continued to have left carotid and vertebrobasilar TIA's being on oral anticoagulation. The patient became asymptomatic only after mitral valve replacement was performed.

CONCLUSIONS

This case illustrates the difficulty distinguishing between gelastic epilepsy and TIA's in cases of PLC episodes and discuss the neuroanatomic bases and pathophysiology of this rare condition.

Hypothalamic hamartomas. Part 1. Clinical, neuroimaging, and neurophysiological characteristics

Hypothalamic hamartomas are uncommon but well-recognized developmental malformations that are classically associated with gelastic seizures and other refractory seizure types. The clinical course is often progressive and, in addition to the catastrophic epileptic syndrome, patients commonly exhibit debilitating cognitive, behavioral, and psychiatric disturbances. Over the past decade, investigators have gained considerable knowledge into the pathobiological and neurophysiological properties of these rare lesions. In this review, the authors examine the causes and molecular biology of hypothalamic hamartomas as well as the principal clinical features, neuroimaging findings, and electrophysiological characteristics. The diverse surgical modalities and strategies used to manage these difficult lesions are outlined in the second article of this 2-part review.

Clinical spectrum and difficulties in management of hypothalamic hamartoma in a developing country

AIM

We describe the clinical features, treatment and prognosis in a series of patients with epilepsy secondary to hypothalamic hamarthomas (HH) in a developing country.

MATERIALS AND METHODS

Eight patients with epilepsy and HH were included between 1997 and 2006. We analyzed gender, age, age at seizure onset (ASO), seizure types (ST), mental retardation (MR), precocious puberty (PP), electroencephalogram (EEG)-magnetic resonance imaging (MRI) features and response to treatment.

RESULTS

Mean age 25.1 years, 2/6 female/male, none had PP, ASO 4.5 years. Complex partial seizure were the most frequent (100%), mean similar to those seen in temporal (62.5%) or frontal lobe epilepsy (37.5%). Exactly 87.5% developed gelastic seizures (GS). Half of the patients showed MR. Mild-to-severe MR was associated with the presence of multiple ST including atonic and complex partial seizures with frontal semiology. Interictal EEG was abnormal in 87.5% patients. Video EEG was performed in three cases with unspecific findings. HH were small and sessile in seven patients whereas large and pedunculated in one. All patients were refractory to medical treatment. In five, an additional procedure was performed without any significant improvement.

CONCLUSION

These series show the heterogeneous spectrum of this entity and the difficulties in its treatment in a developing country.

[Supratentorial tumors]

Magnetic resonance imaging is a routine diagnostic measure for a suspected intracerebral mass. Computed tomography is usually also indicated. Further diagnostic procedures as well as the interpretation of the findings vary depending on the tumor location. This contribution discusses the symptoms and diagnostics for supratentorial tumors separated in relation to their intra- or extracranial location. Supratentorial tumors include astrocytoma, differentiated by their circumscribed and diffuse growth, ganglioglioma, ependyoma, neurocytoma, primitive neuroectodermal tumors (PNET), oligodendroglioma, dysem-bryoplastic neuroepithelial tumors (DNET), meningoangiomatosis, pineal tumors, hamatoma, lymphoma, craniopharyngeoma and metastases. The supratentorial extracranial tumors include the choroid plexus, colloid cysts, meningeoma, infantile myofibromatosis and lipoma. The most common sub-forms, especially of astrocytoma, will also be presented.

Hypothalamic hamartoma: basic mechanisms of intrinsic epileptogenesis

The hypothalamic hamartoma (HH) is a rare developmental malformation commonly associated with gelastic seizures that are notoriously refractory to medical therapy. Recent evidence supports the intrinsic seizure propensity of HH. Despite increasing clinical recognition of this condition, the mechanisms of seizure genesis in HH tissue remain unclear. This review summarizes the histochemical and electrophysiological properties of HH neurons, and relates these findings to those characteristics identified in other types of epileptic tissue. Initial studies have revealed two distinct populations of neurons in surgically resected HH tissue. One group consisted of small gamma-aminobutyric acid (GABA)-expressing neurons that occurred principally in clusters and displayed spontaneous rhythmic firing. The second group was composed of large, quiescent, pyramidal-like neurons with more extensive dendritic and axonal arborization. We propose that the small, spontaneously firing GABAergic neurons send inhibitory projections to and drive the synchrony of large output neurons. These observations constitute the basis for future investigations aimed at elucidating the mechanisms of subcortical epileptogenesis.

Hypothalamic Hamartoma and Infantile Spasms

PURPOSE

A small number of patients with hypothalamic hamartoma (HH) present with infantile spasms (IS) as an initial or early seizure type. We describe the clinical features of IS associated with HH.

METHODS

Our series of patients with HH and epilepsy was reviewed to identify cases with a history of IS. The clinical features and neuroradiological findings in this study group were compared to a control group of patients with HH and refractory epilepsy, but without a history of IS.

RESULTS

We identified six patients with HH and a history of IS in this series (n = 122, 4.9%). Five of the six are male. Four of the six patients (67%) developed IS as their first seizure type. The mean age for onset of IS was 6.2 months (range 4-9 months). Results of electroencephalographic (EEG) study at the time of IS diagnosis showed hypsarrhythmia in two (33%). Five patients were treated with adrenocorticotropic hormone (ACTH), and four of the five (80%) responded with control of IS. However, these patients developed other seizure types, and were ultimately refractory to medical management. Aside from the IS, no significant differences in clinical and imaging features were determined between the study group and the control group.

CONCLUSIONS

HH should be included in the differential diagnosis for infants presenting with IS. These patients may have hypsarrhythmia on initial EEG, and may respond to ACTH treatment with improvement of IS. However, all became refractory with other seizure types, more commonly seen in HH patients. Focal pathologies associated with IS may be subcortical, as well as cortical, in nature. We have not identified any predictive features for the occurrence of IS in the HH population.

Transcallosal resection of hypothalamic hamartoma for intractable epilepsy

PURPOSE

To present the results of transcallosal surgical resection of hypothalamic hamartoma (HH) in 26 patients with refractory epilepsy in a prospective outcome study.

METHODS

Patients with refractory epilepsy symptomatic to HH were referred for surgical resection of their HH (mean age, 10.0 years; range, 2.1-24.2 years). A transcallosal, interforniceal approach was used to remove and/or disconnect the hamartoma. Volumetry was obtained on pre- and postoperative brain MRI scans to determine percentage of resection. Outcome assessment included determination of postoperative seizure frequencies in comparison to baseline and the incidence of postoperative complications. Postoperative changes in cognitive and behavioral functioning, in comparison to baseline, were elicited by parental report.

RESULTS

The average postoperative follow-up interval was 20.3 months (range, 13-28 months). Fourteen (54%) patients were completely seizure free, and nine (35%) had at least a 90% improvement in total seizure frequency. Parents reported postoperative improvement in behavior in 23 (88%) patients and in cognition in 17 (65%) patients. Transient postoperative memory disturbance was seen in 15 (58%) patients, but persisted in only two (8%). Two (8%) patients had persisting endocrine disturbance requiring hormone replacement therapy (diabetes insipidus and hypothyroidism in one each). With univariate analysis, the likelihood of a seizure-free outcome correlated with younger age, shorter lifetime duration of epilepsy, smaller preoperative HH volume, and 100% HH resection.

CONCLUSIONS

Refractory epilepsy associated with HH can be safely and effectively treated with surgical resection by a transcallosal, interforniceal approach. Short-term memory deficits appear to be transient for most patients, and family perception of the impact of surgery on cognitive and behavioral domains is favorable. Complete resection yields the best result.

The clinical spectrum and natural history of gelastic epilepsy-hypothalamic hamartoma syndrome

PURPOSE

To delineate the clinical spectrum and patterns of evolution of epilepsy with gelastic seizures related to hypothalamic hamartoma (HH).

PATIENTS AND METHODS

We evaluated patients with HH, observed between 1986 and 2002 for whom at least one ictal video-EEG or EEG recording of gelastic seizures was available.

RESULTS

Six subjects (four male, two female) with sessile HH between 0.8 and 1.7 cm in diameter were identified. The onset of gelastic seizures was between 2 months and 20 years. It evolved to secondary generalized epilepsy in one case, and to drug-resistant partial epilepsy in the other five from 2 to 13 years after onset. No patient showed precocious puberty. Severe cognitive impairment developed in the patient with secondary generalized epilepsy, and a mild cognitive defect in two others. Patients with an HH below 1cm did not show neuropsychological or behavioural disturbances. Drug resistance occurred in all cases. Surgical removal of HH markedly improved the clinical evolution in two patients.

CONCLUSIONS

Gelastic epilepsy-HH syndrome can differ in severity and evolution. A catastrophic evolution and drug resistance can be reversed by surgical or by gamma-knife ablation of HH.

The hypothalamic hamartoma: a model of subcortical epileptogenesis and encephalopathy

Although uncommon, the hypothalamic hamartoma (HH) is often associated with a devastating clinical syndrome, which may include refractory epilepsy, progressive cognitive decline, and deterioration in behavioral and psychiatric functioning. Contrary to conventional thinking which attributed seizure origin to cortical structures, the hamartoma itself has now been firmly established as the site of intrinsic epileptogenesis for the gelastic seizures (i.e., characterized by unusual mirth) peculiar to this disorder. It also appears that the HH contributes to a process of secondary epileptogenesis, with eventual cortical seizure onset of multiple types in some patients. Anticonvulsant medications are known to be poorly effective in this disorder. Treatment, including some innovative approaches to surgical resection, is now targeted directly at the HH itself, with impressive results. Younger patients, in particular, may avoid the deteriorating course described earlier. Access to tissue from larger numbers of patients at single or collaborating centers specializing in HH surgery will allow for research into the fundamental mechanisms producing this little understood disorder. Refractory epilepsy associated with HH is the premier human model for subcortical epilepsy and an excellent model for secondary epileptogenesis and epileptic encephalopathy.

Gamma knife surgery for epilepsy related to hypothalamic hamartomas

OBJECTIVE

Drug resistant epilepsy associated with hypothalamic hamartoma (HH) can be cured by microsurgical resection of the lesion. Morbidity and mortality risks of microsurgery in this area are significant. Gamma Knife Surgery's (GKS) reduced invasivity seems to be well adapted. In view of the severity of the disease and risks of surgical resection it is crucial to evaluate GKS for this indication. A first retrospective study has shown a very good safety and efficacy level but for a more reliable evaluation a prospective study would be required.

METHODS

Between Oct 1999 and July 2002, 30 patients with HH and associated severe epilepsy were included. Seizure semiology (video EEG) and frequency, behavioural disturbances, neuropsychological performance, endocrinological status, sleep electroclinical abnormalities, MR imaging, and visual function were systematically evaluated before and after GKS (6, 12, 18, 24, 36 months). Twenty patients had experienced precocious puberty at a median age of 3,7 (0-9). Range of maximum diameter was from 7,5 to 23 mm with only 3 larger than 18 mm. The median marginal dose was 17 gy (14-20).

RESULTS

Sufficient follow up for final evaluation is not yet available. Only 6 patients have a follow-up of more than 12 months and 19 more than 6 months. However a lot of very dramatic changes did occur during that period in this group. Among the 19 patients with more than 6 months of follow-up, a lot had already experienced an increase of gelastic seizures around 3 months (3), an improvement in their seizure rate (18), behaviour (9), sleep (3), and EEG background activity (3), a cessation of partial complex seizures (7). No complications have occurred till now except one patient experiencing at 5 months a hyperthermia without infection and concomitant increase of gelastic seizures both ceasing suddenly and spontaneously after 15 days.

CONCLUSION

Our first results indicate that GKS is as effective as microsurgical resection and very much safer. GKS also allows to avoid the vascular risk related to radiofrequency lesioning or stimulation. The disadvantage of radiosurgery is its delayed action. Longer follow-up is mandatory for a serious evaluation of the role of GKS. Results are faster and more complete in patients with smaller lesions inside the 3rd ventricle (grade II). The early effect on subclinical discharges turns out to play a major role in the dramatic improvement of sleep quality, behaviour, developmental acceleration at school.

Hypothalamic hamartoma with gelastic seizures in Swedish children and adolescents

BACKGROUND

Hypothalamic hamartoma with gelastic seizures (HHGS) is an uncommon, often unrecognized, epileptic syndrome with onset of symptoms during childhood.

AIM

In order to study the occurrence, clinical symptoms and different investigations of HHGS in Swedish children and adolescents, a nationwide survey was undertaken. Methods. Twelve patients, three females, aged 5 to 19 years were identified and their hospital records reviewed. MRI examinations were reinvestigated.

RESULTS

Gelastic seizures were noted before the age of six months in seven patients in at least three as early as the neonatal period. During the course of disease one or more other seizure types developed in 11 patients. Behaviour disorder became subsequently obvious in ten patients, and mental retardation was diagnosed in seven. Precocious puberty was diagnosed in five patients. A total of 46 MRI examinations were performed in 11 patients, revealing hypothalamic tumors, eight of which were drooping with a broad base. Interictal and ictal EEG examinations were pathological in 10 patients with nonspecific results. Nonspecific results were also found on SPECT and PET performed in six and two patients, respectively. Available antiepileptic drugs had little or no effect on gelastic seizures, but some effect on other seizure types. Precocious puberty was treated with a GnRH-agonist. Neurosurgical treatment of the hypothalamic hamartoma, performed in three patients, had a rather good outcome concerning gelastic seizures and behaviour. Vagal nerve stimulation in five patients had no effect.

CONCLUSIONS

Review of the literature and experience from this group's own cases confirms that early diagnosis of HHGS is important. Hypothalamic hamartoma should be considered in any child with laughing attacks. MRI investigation is compulsory, and neurosurgery the most important treatment.

Neural correlates of laughter and humour

Although laughter and humour have been constituents of humanity for thousands if not millions of years, their systematic study has begun only recently. Investigations into their neurological correlates remain fragmentary and the following review is a first attempt to collate and evaluate these studies, most of which have been published over the last two decades. By employing the classical methods of neurology, brain regions associated with symptomatic (pathological) laughter have been determined and catalogued under other diagnostic signs and symptoms of such conditions as epilepsy, strokes and circumspect brain lesions. These observations have been complemented by newer studies using modern non-invasive imaging methods. To summarize the results of many studies, the expression of laughter seems to depend on two partially independent neuronal pathways. The first of these, an 'involuntary' or 'emotionally driven' system, involves the amygdala, thalamic/hypo- and subthalamic areas and the dorsal/tegmental brainstem. The second, 'voluntary' system originates in the premotor/frontal opercular areas and leads through the motor cortex and pyramidal tract to the ventral brainstem. These systems and the laughter response appear to be coordinated by a laughter-coordinating centre in the dorsal upper pons. Analyses of the cerebral correlates of humour have been impeded by a lack of consensus among psychologists on exactly what humour is, and of what essential components it consists. Within the past two decades, however, sufficient agreement has been reached that theory-based hypotheses could be formulated and tested with various non-invasive methods. For the perception of humour (and depending on the type of humour involved, its mode of transmission, etc.) the right frontal cortex, the medial ventral prefrontal cortex, the right and left posterior (middle and inferior) temporal regions and possibly the cerebellum seem to be involved to varying degrees. An attempt has been made to be as thorough as possible in documenting the foundations upon which these burgeoning areas of research have been based up to the present time.

Different electroclinical manifestations of the epilepsy associated with hamartomas connecting to the middle or posterior hypothalamus

PURPOSE

The epilepsy associated with hypothalamic hamartomas (HHs) has typical clinical, electrophysiologic, and behavioral manifestations refractory to drug therapy and with unfavorable evolution. It is well known that only sessile lesions produce epilepsy, but no correlation has been established between the different types of sessile hamartomas and the diverse manifestations of the epilepsy. We correlate anatomic details of the hamartoma and the clinical and neurophysiologic manifestations of the associated epilepsy.

METHODS

HHs of seven patients with epilepsy (ages 2- 25 years) were classified as to lateralization and connection to the anteroposterior axis of the hypothalamus by using high-resolution brain magnetic resonance imaging. We correlated the anatomic classification with the clinical and neurophysiologic manifestations of the epilepsy as evaluated in long-term (24 h) video-EEG recordings.

RESULTS

HHs ranged in size from 0.4 to 2.6 cc, with complete lateralization in six of seven patients. Ictal manifestations showed good correlation with the lobar involvement of ictal/interictal EEGs. These manifestations suggest the existence of two types of cortical involvement, one associated with the temporal lobe, produced by hamartomas connected to the posterior hypothalamus (mamillary bodies), and the other associated with the frontal lobe, seen in lesions connecting to the middle hypothalamus.

CONCLUSIONS

A consistent clinical and neurophysiologic pattern of either temporal or frontal lobe cortical secondary involvement was found in the patients of our series. It depends on whether the hamartoma connects to the mamillary bodies (temporal lobe cases) or whether it connects to the medial hypothalamus (frontal lobe cases).

Hypothalamic hamartomas: seven cases and review of the literature

Hypothalamic hamartomas constitute rare developmental lesions associated with gelastic epilepsy and/or precocious puberty (PP). We elected to review cases encountered at our center (7 patients) and the existing literature (277 patients) to obtain a better understanding of the clinical aspects, pathogenesis, and treatment of this entity. Evidence suggests that gelastic seizures are due to intrinsic epileptogenicity. The cause of the subsequent development of other seizure types, cognitive decline, and diffuse spike-and-wave pattern remains unresolved and is addressed. Anticonvulsants often fail to control seizures and different surgical options are available. Available evidence suggests that a resection through a subtemporal approach is best for lesions that are pedunculated or with a significant prepontine component, while a transcallosal approach is more appropriate for sessile lesions with an intraventricular component. Gamma knife surgery may be especially useful for small sessile lesions, failed partial resections, or patients not appropriate or refusing open surgery.

Disconnecting surgical treatment of hypothalamic hamartoma in children and adults with refractory epilepsy and proposal of a new classification

A series of 17 patients aged from 9 months to 32 years with refractory epilepsy due to hypothalamic hamartoma were treated by total removal (one case) and disconnection (16 cases) between 1997 and 2002. The mean age at seizure onset was 16 months. Sixteen patients had gelastic seizures, 14 had partial seizures and three had generalized tonic-clonic seizures. The mean seizure frequency was 21 per day. Four patients had borderline intelligence quotient and the others were mentally retarded. Five patients presented with precocious puberty, one with acromegaly, and four suffered from obesity. Brain magnetic resonance imaging, performed at least twice in each patient, showed the hamartoma as a stable homogeneous interpeduncular mass implanted either on the mammilary tubercle or on the wall of the third ventricle with variable extension to the bottom. Ictal single photon emission computed tomography, performed in four patients, showed hyperperfusion within the hamartoma in two patients. Twenty-five operations were performed in the 17 patients. The first patient underwent total removal of the hamartoma, whereas the following 16 patients underwent disconnection through open surgery (14 procedures) and/or endoscopy (9 procedures). Eight patients became seizure-free, one patient had only brief gelastic seizures, and eight patients were dramatically improved with a mean follow up of 18.6 months (8 days to 43 months). Surgery was safe in all but two patients: the first patient had transient hemiplegia and the third cranial nerve paresis, and the other developed hemiplegia due to ischemia of the middle cerebral artery territory. The quality of life, and behavior and school performance were greatly improved in most patients. Our series illustrates the feasibility and relative safety of disconnection surgery for hypothalamic hamartomas with seizure relief in 53% of patients and dramatic improvement in the others. Surgical observations led us to propose a new anatomical classification according to the anatomical relationship between the hamartoma and the adjacent hypothalamus and third ventricle. Endoscopic disconnection seems to be a very safe way to treat hamartomas in intraventricular locations.

Gelastic seizure with tectal tumor, lobar holoprosencephaly, and subependymal nodules: clinical report

Gelastic seizures are characterized by inappropriate, stereotyped laughter and are often first recognized when other epileptic manifestations occur. They are frequently associated with hypothalamic hamartomas. Central nervous system developmental abnormalities are rarely reported with gelastic seizures. There is only one case report of gelastic seizure caused by holoprosencephaly. We report a 2-year-old girl with multiple brain structural abnormalities including tectal tumor (possibly hamartoma), multiple subependymal nodules, and holoprosencephaly. She developed seizures during the newborn period and presented with gelastic seizure and simple partial seizure at 3 months of age.

Imaging in epilepsy: a paediatric perspective

Assessment of a child with epilepsy involves a number of key stages, the most crucial being clinical evaluation where the presence of seizure activity and seizure type is identified. Subsequent imaging is not required in all children. In those selected for further investigation, imaging techniques are broadly divided into structural and functional studies. MRI currently provides the best structural data, with nuclear medicine and specialized MR techniques giving supportive functional information. CT now has a much diminished role. This review highlights the role of different imaging modalities in the investigation of childhood epilepsy, as well as some of the practicalities of imaging children, and areas where recent advances have been made. It is hoped that the overview and information provided will help both the specialist and the general radiologist make informed decisions regarding how to best image a child with epilepsy.

Aggression and psychiatric comorbidity in children with hypothalamic hamartomas and their unaffected siblings

OBJECTIVE

To assess aggression and psychiatric comorbidity in a sample of children with hypothalamic hamartomas and gelastic seizures and to assess psychiatric diagnoses in siblings of study subjects.

METHOD

Children with a clinical history of gelastic seizures and hypothalamic hamartomas (n = 12; age range 3-14 years) had diagnoses confirmed by video-EEG and head magnetic resonance imaging. Structured interviews were administered, including the Diagnostic Interview for Children and Adolescents-Revised Parent Form (DICA-R-P), the Test of Broad Cognitive Abilities, and the Vitiello Aggression Scale. Parents were interviewed with the DICA-R-P about each subject and a sibling closest in age without seizures and hypothalamic hamartomas. Patients were seen from 1998 to 2000.

RESULTS

Children with gelastic seizures and hypothalamic hamartomas displayed a statistically significant increase in comorbid psychiatric conditions, including oppositional defiant disorder (83.3%) and attention-deficit/hyperactivity disorder (75%). They also exhibited high rates of conduct disorder (33.3%), speech retardation/learning impairment (33.3%), and anxiety and mood disorders (16.7%). Significant rates of aggression were noted, with 58% of the seizure patients meeting criteria for the affective subtype of aggression and 30.5% having the predatory aggression subtype. Affective aggression was significantly more common (p < .05). Unaffected siblings demonstrated low rates of psychiatric pathology on semistructured parental interview and no aggression as measured by the Vitiello Aggression Scale.

CONCLUSIONS

Children with hypothalamic hamartomas and gelastic seizures had high rates of psychiatric comorbidity and aggression. Parents reported that healthy siblings had very low rates of psychiatric pathology and aggression.

Transcallosal resection of hypothalamic hamartomas, with control of seizures, in children with gelastic epilepsy

OBJECTIVE

Hypothalamic hamartomas (HHs) are associated with precocious puberty and gelastic epilepsy; the seizures are often refractory to antiepileptic medications and associated with delayed development and disturbed behavior. The current opinion is that surgery to treat intrahypothalamic lesions is formidable and that complete excision is not technically achievable. We report our experience with a transcallosal approach to the resection of HHs.

METHODS

Five children (age, 4-13 yr) with intractable epilepsy and HHs underwent preoperative clinical, electroencephalographic, and imaging evaluations. Two patients experienced only gelastic seizures, and three patients experienced mixed seizure disorders with drop attacks; all experienced multiple daily seizures. Patients were evaluated with respect to seizures, cognition, behavior, and endocrine status 9 to 37 months (mean, 24 mo) after surgery. The HHs were approached via a transcallosal-interforniceal route to the third ventricle and were resected using a microsurgical technique and frameless stereotaxy.

RESULTS

Complete or nearly complete (>95%) excision of the HHs was achieved for all patients, with no adverse neurological, psychological, or visual sequelae. Two patients experienced mild transient diabetes insipidus after surgery. Two patients developed appetite stimulation, but no other significant endocrinological sequelae were observed. Three patients are seizure-free and two patients have experienced only occasional, brief, mild gelastic seizures after surgery, all with reduced antiepileptic medications. On the basis of parental reports and our own subjective observations, the children also exhibited marked improvements in behavior, school performance, and quality of life.

CONCLUSION

Complete or nearly complete resection of HHs can be safely achieved via a transcallosal approach, with the possibility of seizure freedom and neurobehavioral improvements.

Gamma Knife Surgery for Epilepsy Related to Hypothalamic Hamartomas

OBJECTIVE

Drug-resistant epilepsy associated with hypothalamic hamartomas (HHs) can be cured by microsurgical resection of the lesions. Morbidity and mortality rates for microsurgery in this area are significant. Gamma knife surgery (GKS) is less invasive and seems to be well adapted for this indication.

METHODS

To evaluate the safety and efficacy of GKS to treat this uncommon pathological condition, we organized a multicenter retrospective study. Ten patients were treated in seven different centers. The follow-up periods were more than 12 months for eight patients, with a median follow-up period of 28 months (mean, 35 mo; range, 12–71 mo). All patients had severe drug-resistant epilepsy, including frequent gelastic and generalized tonic or tonicoclonic attacks. The median age was 13.5 years (range, 1–32 yr; mean, 14 yr) at the time of GKS. Three patients experienced precocious puberty. All patients had sessile HHs. The median marginal dose was 15.25 Gy (range, 12–20 Gy). Two patients were treated two times (at 19 and 49 mo) because of insufficient efficacy.

RESULTS

All patients exhibited improvement. Four patients were seizure-free, one experienced rare nocturnal seizures, one experienced some rare partial seizures but no more generalized attacks, and two exhibited only improvement, with reductions in the frequency of seizures but persistence of some rare generalized seizures. Two patients, now seizure-free, were considered to exhibit insufficient improvement after the first GKS procedure and were treated a second time. A clear correlation between efficacy and dose was observed in this series. The marginal dose was more than 17 Gy for all patients in the successful group and less than 13 Gy for all patients in the “improved” group. No side effects were reported, except for poikilothermia in one patient. Behavior was clearly improved for two patients (with only slight improvements in their epilepsy). Complete coverage of the HHs did not seem to be mandatory, because the dosimetry spared a significant part of the lesions for two patients in the successful group.

CONCLUSION

We report the first series demonstrating that GKS can be a safe and effective treatment for epilepsy related to HHs. We advocate marginal doses greater than or equal to 17 Gy and partial dose-planning when necessary, for avoidance of critical surrounding structures.

Retrospective analysis of surgical treatment outcomes for gelastic seizures: a review of the literature

Gelastic seizures are known to be refractory to medical treatment and to date surgical therapy has yet to pinpoint the best treatment for these refractory seizures. There has been a multitude of case reports published on gelastic seizures and different surgical treatments, thus we performed a review of the literature on gelastic seizures and surgical treatments to elucidate the best surgical approaches for medically refractory gelastic seizures.