Surgical management of hypothalamic hamartomas in patients with gelastic epilepsy

Non-invasive sensory neuromodulation in epilepsy: Updates and future perspectives

Epilepsy, one of the most common neurological disorders, often is not well controlled by current pharmacological and surgical treatments. Sensory neuromodulation, including multi-sensory stimulation, auditory stimulation, olfactory stimulation, is a kind of novel noninvasive mind-body intervention and receives continued attention as complementary safe treatment of epilepsy. In this review, we summarize the recent advances of sensory neuromodulation, including enriched environment therapy, music therapy, olfactory therapy, other mind-body interventions, for the treatment of epilepsy based on the evidence from both clinical and preclinical studies. We also discuss their possible anti-epileptic mechanisms on neural circuit level and propose perspectives on possible research directions for future studies.

Increased Gray Matter Density in the Right Mesencephalic Tegmentum Is Associated With Better Engel Classes I and II After Radiosurgery for Hypothalamic Hamartomas

BACKGROUND

Hypothalamic hamartomas (HHs) are disabling congenital lesions, responsible for gelastic seizures frequently associated with catastrophic epilepsies, epileptogenic encephalopathy, and cognitive and psychiatric severe comorbidities. Stereotactic radiosurgery (SRS) is a well-established minimally invasive therapeutic approach.

OBJECTIVE

To assess whether pretherapeutic gray matter density (GMD) correlates with seizure outcome.

METHODS

We used voxel-based morphometry at whole-brain level, as depicted on pretherapeutic standard structural magnetic resonance neuroimaging. We examined 24 patients (10 male patients, 14 female patients; mean age, 12.7 yr; median, 9; range, 5.9-50) treated in Marseille University Hospital, France, between May 2001 and August 2018.

RESULTS

Most relevant anatomic area predicting postoperative Engel classes I and II vs III and IV after SRS for HHs was mesencephalic tegmentum. Higher pretherapeutic GMD in this area was associated with better outcomes for seizure cessation. The only other statistically significant clusters were right cerebellar lobule VIIIb and VIIIa. Lower pretherapeutic GMD in both clusters correlated with better Engel class outcomes. GMD decreased with age in the left mediodorsal thalamus.

CONCLUSION

Seizure cessation after SRS for HHs was associated with higher GMD in mesencephalic tegmental area, acknowledged to be involved in the neural control of explosive vocal behavior in animals. This area is connected by the mamillotegmental bundle to the lateral tuberal nucleus area of the hypothalamus, where HHs are known to rise. In the future, the detection of more gray matter in this "laugh" tegmental area based on pretherapeutic routine structural neuroimaging might help in patient selection for minimally invasive radiosurgery for HH.

[Surgical treatment of epilepsy in patients with hypothalamic hamartomas]

The purpose of this review was to analyze the current ideas about various techniques and methods for treating epilepsy in patients with hypothalamic hamartomas including microsurgery, endoscopy, radiofrequency thermal destruction, stereotactic laser ablation and radiosurgery. Data characterizing their effectiveness, limitations and complications are considered.

CONCLUSION

When choosing the optimal treatment option, it is necessary to take into account patient age and course of disease, anatomical and topographic features of hamartoma location, previous attempts of treatment, opinion of the patient and his guardians, as well as surgical experience.

Safety and effectiveness of surgery for epilepsy in children. Experience of a tertiary hospital in Ecuador

INTRODUCTION

There is sufficient evidence on the usefulness of surgery as a therapeutic alternative for patients with drug-resistant epilepsy; however this treatment is underutilized, especially in developing countries.

METHODS

We describe the outcomes of epilepsy surgery in 27 paediatric patients at Hospital Baca Ortiz in Quito, Ecuador. Our analysis considered the following variables: reduction in seizure frequency, surgery outcome according to the Engel classification, improvement in quality of life, and serious complications due to surgery.

RESULTS

21 corpus callosotomies and 6 resective surgeries were performed. The mean seizure frequency decreased from 465 per month before surgery to 37.2 per month thereafter (p<.001); quality of life scale scores increased from 12.6 to 37.2 (p<.001), and quality of life improved in 72.7% of patients. Regarding resective surgery, 2 patients with temporal lobe epilepsy and one with posterior quadrant epilepsy achieved Engel class IA, and one patient undergoing hemispherotomy due to Rasmussen encephalitis achieved Engel class IIA. Two patients underwent surgery for hypothalamic hamartoma: one achieved Engel III and the other, Engel IA; however, the latter patient died in the medium term due to a postoperative complication. The other major complication was a case of hydrocephalus, which led to the death of a patient with refractory infantile spasms who underwent corpus callosotomy.

CONCLUSIONS

Favourable outcomes were observed in 92.5% of patients.

The Transcallosal Anterior Interfoniceal Approach: A Microsurgical Anatomy Study

Objectives A plethora of surgical strategies have been described to reach deep-seated lesions situated within the third ventricle including the Rosenfeld, or transcallosal anterior interfoniceal (TAIF), approach. First introduced in 2001, it consists of a small callosotomy followed by the midline transseptal dissection of fornices to enter the roof of the third ventricle. The aim of this microsurgical anatomy study is to describe and show each stage of the surgical procedure, focusing on the possible trajectories to anatomical landmarks. Participants A total of 20 adult cadaveric specimens were used in this study. Using ×3 to ×40 magnifications, the surgical dissection was performed in a stepwise fashion, and the transcallosal anterior interforniceal approach was performed, analyzed, and described. Results In 5 specimens of 10, a cavum septum pellucidum was depicted. In 5 cases of 20 after the callosotomy ,the lateral ventricular cavities were reached. Different orientation of the microscope allowed us to define three surgical trajectories to visualize the region of interest without exposing important functional areas. Conclusion The TAIF represents a minimally invasive approach to the third ventricle; its tricky surgical steps make appropriate anatomical dissection training essential to become confident and skilled in performing this approach.

Hypothalamic hamartoma simulating a suprasellar arachnoid cyst: resolution of precocious puberty following microsurgical lesion resection

Hypothalamic hamartomas (HHs) are rare developmental lesions arising from the inferior hypothalamus that may cause gelastic seizures and central precocious puberty. Cystic changes in HHs are rare, usually occurring in giant lesions. The authors describe an unusual case of cystic HH masquerading as a suprasellar arachnoid cyst in an 18-month-old girl presenting with precocious puberty. Microsurgical removal of the lesion led to complete resolution of the precocious puberty on long-term follow-up. This case is the first reported HH with pathological demonstration of corticotropin-releasing hormone immunostaining in the solid tumor and glial cells in the cyst wall of the lesion. The clinical and radiological characteristics of HHs are reviewed, along with the unique surgical strategies used to manage cystic lesions in the suprasellar region.

Surgery for childhood epilepsy

Approximately 60% of all patients with epilepsy suffer from focal epilepsy syndromes. In about 15% of these patients, the seizures are not adequately controlled with antiepileptic drugs; such patients are potential candidates for surgical treatment and the major proportion is in the pediatric group (18 years old or less). Epilepsy surgery in children who have been carefully chosen can result in either seizure freedom or a marked (>90%) reduction in seizures in approximately two-thirds of children with intractable seizures. Advances in structural and functional neuroimaging, neurosurgery, and neuroanaesthesia have improved the outcomes of surgery for children with intractable epilepsy. Early surgery improves the quality of life and cognitive and developmental outcome and allows the child to lead a normal life. Surgically remediable epilepsies should be identified early and include temporal lobe epilepsy with hippocampal sclerosis, lesional temporal and extratemporal epilepsy, hemispherical epilepsy, and gelastic epilepsy with hypothalamic hamartoma. These syndromes have both acquired and congenital etiologies and can be treated by resective or disconnective surgery. Palliative procedures are performed in children with diffuse and multifocal epilepsies who are not candidates for resective surgery. The palliative procedures include corpus callosotomy and vagal nerve stimulation while deep brain stimulation in epilepsy is still under evaluation. For children with "surgically remediable epilepsy," surgery should be offered as a procedure of choice rather than as a treatment of last resort.

Surgical treatment of pediatric epileptic encephalopathies

Pediatric epileptiform encephalopathies are a group of neurologically devastating disorders related to uncontrolled ictal and interictal epileptic activity, with a poor prognosis. Despite the number of pharmacological options for treatment of epilepsy, many of these patients are drug resistant. For these patients with uncontrolled epilepsy, motor and/or neuropsychological deterioration is common. To prevent these secondary consequences, surgery is often considered as either a curative or a palliative option. Magnetic resonance imaging to look for epileptic lesions that may be surgically treated is an essential part of the workup for these patients. Many surgical procedures for the treatment of epileptiform encephalopathies have been reported in the literature. In this paper the evidence for these procedures for the treatment of pediatric epileptiform encephalopathies is reviewed.

Successful treatment of hyperphagia by resection of a hypothalamic hamartoma

Hypothalamic hamartomas (HHs) are benign lesions that are often associated with central precocious puberty and may present with gelastic seizures. Treatment modalities for HH include medical therapy with long-term gonadotropin-releasing hormone analogs or resection. The authors report the case of a 7-year-old girl who was diagnosed with an HH due to precocious puberty and was treated medically with a gonadotropin-releasing hormone analog for 3 years. Despite normalization of her plasma levels of luteinizing hormone, follicle-stimulating hormone, and estradiol and arrest of her precocious puberty, the patient developed progressive weight gain associated with extreme hyperphagia and morbid obesity by the age of 10 years. Her compulsive eating patterns were refractory to counseling and other interventions attempted by her parents and physicians. After resection of the HH, her hyperphagia resolved and her weight stabilized. To the authors' knowledge, this is the first report describing resection of an HH for the purpose of treating hyperphagia and obesity.

Image-defined resolution following radiosurgery for hypothalamic hamartoma

The authors present the rare case of complete image-defined resolution of a hypothalamic hamartoma (HH) following Gamma Knife surgery (GKS). A 9-month-old girl presented with an episode of generalized tonic-clonic seizures. Magnetic resonance imaging revealed a left-sided HH, which remained radiologically stable. By 3 years of age the patient had a development delay of 12 months, and experienced 8 gelastic seizures per day while on 2 antiepileptic medications. Thirty-one months after presentation, the patient underwent elective GKS to treat the HH. She has since been seizure free for 22 months, while receiving 3 antiepileptic medications. Twelve months after radiosurgery, MRI revealed complete radiological resolution of the lesion. The authors discuss alternative management options for HH, including microsurgical resection, endoscopic disconnection, stereotactic radiofrequency thermocoagulation, and interstitial radiosurgery. Gamma Knife surgery is a minimally invasive procedure associated with a lower morbidity rate than that of published surgical results. The present case demonstrates the potential for complete image-defined resolution of an HH post-GKS, without long-term neurological sequelae, emphasizing the safety and efficacy of this therapeutic option for the control of epileptic seizures produced by small-volume, surgically inaccessible HHs.

Decreased quality of life in children with hypothalamic hamartoma and treatment-resistant epilepsy

We evaluated health-related quality of life in patients with hypothalamic hamartoma, to see how it differs from that of children with more common neurologic disorders. We used the PedsQL 4.0, along with the Child Behavior Checklist, Hague Seizure Severity Scale, and Side Effects Scale, to evaluate presurgical patients with hypothalamic hamartoma and epilepsy (n = 21). The results were compared with those of age-matched cohorts with migraine (n = 19) and Benign Epilepsy with Central Temporal Spikes (n = 11). In comparison with the migraine group, the patients with hypothalamic hamartoma had decreased health-related quality of life across all domains of the PedsQL 4.0. Compared with the benign epilepsy group, the hypothalamic hamartoma cohort has a significantly lower score in School Function. Comorbid psychomotor retardation was predictive of lower quality of life. Research examining the efficacy of recently developed surgical treatments for hypothalamic hamartoma should include health-related quality of life as an outcome measure.

Deep brain stimulation for the treatment of drug-refractory epilepsy in a patient with a hypothalamic hamartoma. Case report

Hypothalamic hamartomas (HHs) are developmental malformations associated with a range of neurological problems, including intractable seizures. There is increasing evidence of the epileptogenicity of the hamartoma and of the inhomogeneous distribution of the epileptic abnormalities within the malformation. The management strategy for treatment and results differ according to the insertion plane and the extension of the malformation into the hypothalamus. Cases characterized by extensive involvement of the hypothalamus are particularly challenging. The authors describe the case of a patient with drug-resistant epilepsy and a large hypothalamic hamartoma with an extensive area of attachment. The patient underwent implantation of 2 deep brain electrodes. The intraoperative recording showed a synchronous interictal epileptic discharge in the left temporal lobe and on the left side of the lesion. The patient was treated with chronic high-frequency stimulation. No side effects due to the stimulation were reported. At 18 months' follow-up, a reduction in complex partial seizure frequency was reported, but no significant reduction in overall seizure frequency was noticed (p = 0.14, t-test). The authors report on neurophysiological studies of the relationship between HH and epilepsy, and also discuss the literature on chronic high-frequency stimulation, including its rationale and the results of chronic stimulation of various targets for the treatment of drug-resistant epilepsy due to HH.

Repeat surgery for hypothalamic hamartoma in refractory epilepsy

Object

Hypothalamic hamartomas (HHs) often cause pharmacoresistent epilepsy, incapacitating behavioral abnormalities, and cognitive decline. Surgical intervention offers the patient the best opportunity of seizure resolution, which occurs in approximately 50%–60% of patients, and improvement in both cognitive and behavioral difficulties. For those in whom the initial operation has failed, further medical treatment options remain quite limited, whereas, in some cases, a second surgery may improve seizure outcome. The authors retrospectively reviewed their surgical cases to document the success rate and complications of reoperations in patients with HHs.

Methods

Data were obtained from the HH epilepsy surgery database at the Barrow Neurological Institute between 2003 and 2010. Surgical treatment consisted of open and endoscopic procedures, as well as radiosurgery. Demographic details, seizure history, presurgical evaluation, and postoperative follow-up data were evaluated.

Results

In the last 7 years, 21 (13%) of 157 patients underwent reoperation after an initial epilepsy operation. The initial surgical approach in the 21 patients included: endoscopic (8 patients [38%]), transcallosal (8 patients [38%]), orbitozygomatic (3 patients [14%]), and radiosurgery (2 patients [10%]). Of the 8 patients who initially underwent endoscopic resection, repeat procedures included: radiosurgery in 4 (50%), an orbitozygomatic approach in 2 (25%), repeat endoscopy in 1 (12.5%), and a transcallosal approach in 1 (12.5%). Repeat procedures after an initial transcallosal resection included: endoscopic resection in 2 (25%); radiosurgery in 1 (12%); an orbitozygomatic approach in 2 (25%), and repeat transcallosal surgery in 3 (38%). Predominant seizure types that recurred after the first surgery were gelastic seizures, complex partial seizures, and tonic-clonic seizures. Magnetic resonance imaging in all patients prior to reoperation demonstrated either residual HH and/or connection with the mammillary bodies. Review of patients with more than 6 months of follow-up since the last surgery showed greater than 90% reduction in seizures in 4 patients (19%) and by 50%–90% in 10 patients (48%). Two patients were seizure free, and in 5 patients (24%) there was no change in seizure frequency. Following reoperation, none of the patients had any worsened behavioral issues such as increased rage attacks or disruptive violent behavior. New postoperative complications after reoperation included hemiparesis, thalamic stroke (asymptomatic and symptomatic), hyperphagia, and panhypopituitarism.

Conclusions

Reoperation should be considered in selected patients with HH in whom initial epilepsy surgery fails because more than half the patients have significant reductions in seizure.

Long-term cognitive outcome after transcallosal resection of hypothalamic hamartoma in older adolescents and adults with gelastic seizures

Hypothalamic hamartomas (HHs) are typically associated with pharmacologically intractable gelastic seizures, which often develop into complex partial and/or generalized tonic-clonic seizures. The transcallosal, anterior interforniceal (TAIF) approach to HH resection has been shown to be safe and to result in good seizure frequency reduction. We documented postsurgical cognitive functioning and examined whether using the TAIF approach with older adolescents and adults affected long-term cognitive outcome. Six older adolescents and adults, who had undergone resection of an HH using the TAIF approach, underwent comprehensive neuropsychological assessment at least 2 years postoperatively. Four of these individuals also had neuropsychological evaluation preoperatively. All participants who were assessed pre- and postoperatively demonstrated long-term improvement in perceptual/visuospatial function after surgery. Three of the four participants also demonstrated lasting reduction in memory function postoperatively. The TAIF approach to HH resection is associated with a high risk of long-term memory impairment in older adolescents and adults.

Current concepts in stereotactic radiosurgery - a neurosurgical and radiooncological point of view

Stereotactic radiosurgery is related to the history of "radiotherapy" and "stereotactic neurosurgery". The concepts for neurosurgeons and radiooncologists have been changed during the last decade and have also transformed neurosurgery. The gamma knife and the stereotactically modified linear accelerator (LINAC) are radiosurgical equipments to treat predetermined intracranial targets through the intact skull without damaging the surrounding normal brain tissue. These technical developments allow a more precise intracranial lesion control and offer even more conformal dose plans for irregularly shaped lesions. Histological determination by stereotactic biopsy remains the basis for any otherwise undefined intracranial lesion. As a minimal approach, it allows functional preservation, low risk and high sensitivity. Long-term results have been published for various indications. The impact of radiosurgery is presented for the management of gliomas, metastases, brain stem lesions, benign tumours and vascular malformations and selected functional disorders such as trigeminal neuralgia. In AVM's it can be performed as part of a multimodality strategy including resection or endovascular embolisation. Finally, the technological advances in radiation oncology as well as stereotactic neurosurgery have led to significant improvements in radiosurgical treatment opportunities. Novel indications are currently under investigation. The combination of both, the neurosurgical and the radiooncological expertise, will help to minimize the risk for the patient while achieving a greater treatment success.