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

Hypothalamic Hamartoma related epilepsy: A systematic review exploring clinical, neuropsychological, and psychiatric outcome after surgery

The post-surgical outcome for Hypothalamic Hamartoma (HH) related epilepsy in terms of seizure freedom (SF) has been extensively studied, while cognitive and psychiatric outcome has been less frequently reported and defined. This is a systematic review of English language papers, analyzing the post-surgical outcome in series of patients with HH-related epilepsy (≥5 patients, at least 6 months follow-up), published within January 2002-December 2022. SF was measured using Engel scale/equivalent scales. We looked at the outcome related to different surgical techniques, and HH types according to Delalande classification. We evaluated the neuropsychological and neuropsychiatric status after surgery, and the occurrence of post-surgical complications. Forty-six articles reporting 1318 patients were included, of which ten pediatric series. SF was reported in 686/1222 patients (56,1%). Delalande classification was reported in 663 patients from 24 studies, of which 70 were type I HH (10%), 320 were type II HH (48%), 189 were type III HH (29%) and 84 were type IV HH (13%). The outcome in term of SF was reported in 243 out of 663 patients. SF was reported in 12 of 24 type I HH (50%), 80 of 132 type II HH (60,6%), 32 of 59 type III HH (54,2%) and 12 of 28 type IV HH (42,9%). SF was reached in 129/262 (49,2%) after microsurgery, 102/199 (51,3%) after endoscopic surgery, 46/114 (40,6%) after gamma knife surgery, 245/353 (69,4%) after radiofrequency thermocoagulation, and 107/152 (70,4%) after MRI-guided laser interstitial thermal therapy. Hyperphagia/weight gain were the most reported surgical complications. Others were electrolyte alterations, diabetes insipidus, hypotiroidism, transient hyperthermia/poikilothermia. The highest percentage of memory deficits was reported after microsurgery, while hemiparesis and cranial nerves palsy were reported after microsurgery or endoscopic surgery. Thirty studies reported developmental delay/intellectual disability in 424/819 (51,7%) patients. 248/346 patients obtained a global improvement (72%), 70/346 were stable (20%), 28/346 got worse (8%). 22 studies reported psychiatric disorders in 257/465 patients (55,3%). 78/98 patients improved (80%), 13/98 remained stable (13%), 7/98 got worse (7%). Most of the patients had non-structured cognitive/psychiatric assessments. Based on the available data, the surgical management in patients with HH related epilepsy should be individualized, aiming to reach not only the best epilepsy result, but also the optimal cognitive and psychiatric outcome.

Direct resection is a safe and effective strategy to control seizures in patients with hypothalamic hamartoma

Achieving favorable seizure outcomes is challenging in patients with seizures resulting from hypothalamic hamartoma. Although minimally invasive and non-invasive surgical procedures are used to treat this population, these procedures have limitations. Therefore, we analyzed the outcomes of patients with hypothalamic hamartoma following direct resection. We included 159 patients with hypothalamic hamartoma who underwent direct resection using the transcallosal interforniceal approach between 2011 and 2018. The relationships between clinical parameters and seizure outcomes were analyzed. In total, 55.3% achieved gross total resection and 25.2% underwent near-total resection. Of all patients, 79.2% were overall seizure-free at one year, but this number dropped to 77.0% at more than five years. Moreover, 88.4% (129/146) reached gelastic seizure (GS)-free status at one year and this number increased to 89.0% (97/109) at more than five years. Seventy-one patients took antiseizure medication (ASM) long-term, 68 took it for one year, and 11 took it for one-half year. The duration of ASM consumption (p < 0.001) and extent of hypothalamic hamartoma resection (p = 0.016) were significant independent predictors of long-term overall seizure-free survival, while the duration of ASM consumption (p = 0.011) and extent of hypothalamic hamartoma resection (p = 0.026) were significant independent predictors of long-term GS-free survival. Most patients' behavior, school performance, and intelligence were not affected after surgery. Direct resection is effective and safe strategy for patients with hypothalamic hamartomas. Hypothalamic hamartomas should be removed as completely as possible, and patients should take ASM long-term following surgery to reach long-term overall seizure-free or GS-free status.

Epileptic encephalopathies secondary to hypothalamic hamartomas treated with radiosurgery: A case series

OBJECTIVE

Hypothalamic hamartomas are congenital lesions that typically present with gelastic seizures, refractory epilepsy, neurodevelopmental delay, and severe cognitive impairment. Surgical procedures have been reported to be effective in removing the hamartomas, however, they are associated with significant morbidity. Therefore, it is not considered a safe therapeutic modality. Image-guided robotic radiosurgery (CyberKnife® Radiosurgery System) has been shown to provide good outcomes without lasting complications.

METHODS

This series of cases describes the clinical, radiological, radiotherapeutic, and postsurgical outcomes of five patients with epileptic encephalopathies secondary to hypothalamic hamartomas who were treated with CyberKnife®.

RESULTS

All patients exhibited refractory epilepsy with gelastic seizures and were unsuitable candidates for surgical resection The prescribed dose ranged between 16 and 25 Gy, delivered in a single fraction for four patients and five fractions for one patient while adhering strictly to visual pathway constraints. After radiosurgery, four patients maintained seizure control (one with an Engel class Ia, three with an Engel class 1d), and another presented sporadic, nondisabling gelastic seizures (with an Engel class IIa). After 24-26 months of follow-up, in three patients, their intelligence quotient scores increased. No complications were reported.

SIGNIFICANCE

This report suggests that Cyberknife may be a good option for treating hypothalamic hamartoma, particularly in cases where other noninvasive alternatives are unavailable. Nevertheless, additional studies are essential in order to evaluate the effectiveness of the technique in these cases.

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.

Microsurgical management of complex hypothalamic hamartomas in the era of minimally invasive therapy: a case series and narrative review

INTRODUCTION

There has been a paradigm shift in the management of hypothalamic hamartoma (HH) from traditional microsurgical techniques to less invasive alternatives. However, large and extensive HH may fail to respond to these therapies, ultimately necessitating craniotomies.

METHODS

All patients who underwent microsurgical resection of a complex HH by the 2 senior authors from 2011-2021 were included. Charts were retrospectively reviewed and demographic, clinical, imaging, and outcome data were recorded.

RESULTS

8 patients (mean age 7 years) were included. 2 had failed previous treatments. All 7 presented with gelastic seizures and cognitive dysfunction, 6 exhibited central precocious puberty, and 3 had behavioral problems. Mean lesion size was 21.6 mm and all had interpeduncular extension, 5 had intraventricular extension (Delalande type I: 3, type III: 4, type IV: 1). A frontotemporal orbitozygomatic (FTOZ) approach with optic nerve decompression was used in all patients, supplemented by another approach in 3 (endoscopic transventricular: 3, transcallosal: 1). Gross total resection was achieved in 6 patients and subtotal resection in 2. Transient complications occurred in 3 patients (37.5%): self-limited sodium imbalance (n=3), subdural hygroma (n=2). Permanent complications occurred in 2 patients (25%): perforator infarct (n=1), short-term memory loss (n=1). All patients experienced seizure resolution with preserved hypothalamic-pituitary axis function. After a mean follow-up of 41 months (2-66), 7 patients remain seizure-free, while 1 has rare seizures. Cognitive and behavioral symptoms improved in all patients.

CONCLUSION

For large HH with interpeduncular extension, microsurgery via the FTOZ approach is a safe and highly effective treatment modality.

Long-term cognitive outcome after radiosurgery in epileptic hypothalamic hamartomas and review of the literature

OBJECTIVE

Epileptic patients with hypothalamic hamartoma (HH) frequently present cognitive impairments. Surgical techniques aiming at HH can be very efficient for epilepsy relief and cognitive improvement but are also demonstrated to carry a significant risk of additional reduction in memory function in these already disabled patients. Gamma knife radiosurgery (GKS) offers an efficient minimally invasive procedure. We evaluated the effect of stereotactic radiosurgery on cognitive outcome.

METHODS

We designed a prospective single-center case series study. Thirty-nine epileptic patients (median age = 17 years, range = 4-50) with HH underwent preoperative and postoperative testing of intelligence quotient (IQ; all patients), including a working memory component, and other memory function testing (for patients ≥16 years old). All patients were prospectively evaluated and underwent complete presurgical and postsurgical clinical, electrophysiological, endocrinal, and visual assessments. In all patients, the postoperative assessment was performed at least 3 years after radiosurgery. We explored what variables correlate with cognitive outcome. Literature review was done for other surgical techniques and their risks for cognitive complications after surgery.

RESULTS

No decline was observed in intellectual ability (including working memory) after GKS, and no memory decline was seen in adults. We observed significant improvement (>1 SD in z-score) in working memory index (46%) and processing speed index (35%), as well as improvement in full-scale IQ (24%), verbal comprehension index (11%), perceptual organization index (21%), verbal learning (20%), and visual learning (33%). Before GKS, the probability of seizure cessation was higher in patients with higher cognitive performance. After GKS, the cognitive improvement was significantly higher in the seizure-free patients compared to the non-seizure-free patients.

SIGNIFICANCE

We found clear cognitive improvement in a high percentage of patients but importantly no significant decline in intellectual ability (including working memory) and no decline in memory in adult patients 3 years after GKS. GKS compares favorably to the other surgical techniques in terms of cognitive outcome, with similar seizure freedom.

Management of Epilepsy Due to Hypothalamic Hamartomas

A hypothalamic hamartoma consists of hyperplastic heterotopic tissue growing in a disorganized fashion. These lesions occur in about one per 50,000 to 100,000 people. Hypothalamic hamartomas can cause intrinsic epileptogenesis leading to gelastic seizures. Surrounding cortical structures may also develop secondary epileptogenesis. Persistent seizures caused by hypothalamic hamartomas can be debilitating and result in significant cognitive and behavioral impairment. Early recognition and treatment is important in controlling seizures and in preventing further cognitive deterioration. Some patients experience improved cognition and behavior following early treatment, suggesting that hypothalamic hamartomas represent a reversible epileptic encephalopathy. The outcome of epilepsy associated with these lesions has significantly evolved with the availability of new treatment techniques and an improved understanding of its pathogenesis. Increasing evidence supporting the role of hypothalamic hamartomas as a cause of gelastic seizures and secondary epileptogenesis has led to more frequent use of surgery as the definitive treatment. Several minimally invasive procedures have been devised, including neuroendoscopic approaches and different stereotactic radio and laser ablation techniques. Each of these techniques can lead to unique adverse events. We review the various classification schemes used to characterize hypothalamic hamartomas and the recommended surgical approaches for each subtype. We also review the literature for currently available treatment modalities and compare their efficacy in controlling seizures and their safety profiles.

Psychiatric comorbidity with hypothalamic hamartoma: Systematic review for predictive clinical features

OBJECTIVE

We conducted a systematic review of the English-language literature to identify clinical features associated with a higher risk of psychiatric symptoms (aggression and rage behaviors) in patients with hypothalamic hamartoma (HH) and epilepsy.

METHODS

Two publicly-accessible databases (PubMed and Cochrane Library) were searched for Hypothalamic Hamartoma AND Epilepsy. We identified peer-reviewed original research publications (case reports or clinical series; N=19) in which clinical data was provided on an individual basis. Subjects were cohorted into those with (N=51) and without (N=68) behavioral aggression. Multiple clinical features were collated and subjected to univariate analysis to determine possible differences between these two cohorts.

RESULTS

The presence of aggression significantly correlated with 1) male gender, 2) younger age at time of first seizure onset, 3) the presence of intellectual disability, and 4) the presence of multiple seizure types (versus gelastic seizures only). For those patients undergoing surgical treatment, aggression also correlated with younger age at the time of surgical intervention.

CONCLUSION

Possible predictive clinical features for the presence of aggression and rage behaviors in patients with hypothalamic hamartoma and epilepsy are identified. These results may contribute to the complex treatment decisions that are unique to this population.

Memory outcome one year after stereotactic interstitial radiosurgery in patients with epilepsy due to hypothalamic hamartomas

Epileptic seizures caused by hypothalamic hamartomas (HHs) are highly pharmacoresistant. Resective surgical approaches have shown some efficacy in controlling seizures; however, they bear a significant risk of postoperative mnemonic deterioration due to the close anatomical proximity of the HHs to structures essential for memory functions. We report on cognitive outcome in 26 patients with structural epilepsy due to HHs one year after interstitial radiosurgery. Individually, deteriorations occurred more frequently in declarative memory functions (in 20 to 50% of the patients), whereas more than 80% of the patients revealed stable or even improved performance in attentional functions. Preoperative better memory functions were associated with higher risk of postoperative performance decline. After radiosurgery, half of the patients showed more than 50%, and some up to 90%, of seizure reduction. Hypothalamic hamartoma volumes were significantly reduced at follow-up. Transient radiogenic edema found in 10/26 patients was not associated with further cognitive decline after radiosurgery. These results are highly relevant for therapeutic decisions and patient consultation on timing and choice of nonmedical treatment options for HHs.

Hypothalamic hamartomas: optimal approach to clinical evaluation and diagnosis

Hypothalamic hamartomas (HHs) present a difficult medical problem, manifested by gelastic seizures, which are often medically intractable. Although existing techniques offer modest surgical outcomes with the potential for significant morbidity, the relatively novel technique of magnetic resonance imaging (MRI)-guided stereotactic laser ablation (SLA) offers a potentially safer, minimally invasive method with high efficacy for the HH treatment. We report here on 14 patients with medically refractory gelastic epilepsy who underwent stereotactic frame-based placement of an MR-compatible laser catheter (1.6 mm diameter) through a 3.2-mm twist drill hole. A U.S. Food and Drug Administration (FDA)-cleared laser surgery system (Visualase, Inc.) was utilized to ablate the HH, using real-time MRI thermometry. Seizure freedom was obtained in 12 (86%) of 14 cases, with mean follow-up of 9 months. There were no permanent surgical complications, neurologic deficits, or neuroendocrine disturbances. One patient had a minor subarachnoid hemorrhage that was asymptomatic. Most patients were discharged home within 1 day. SLA was demonstrated to be a safe and effective minimally invasive tool in the ablation of epileptogenic HH. Because use of SLA for HH is being adopted by other medical centers, further data will be acquired to help treat this difficult disorder.

Hypothalamic hamartomas. Part 2. Surgical considerations and outcome

Hypothalamic hamartomas are uncommon developmental heterotopic masses composed of an intermixed array of neurons, glia, and myelinated fibers closely associated with the mammillary bodies. Gelastic seizures, the hallmark feature of hypothalamic hamartomas, commonly present in early childhood. However, patients usually also display a disabling clinical syndrome, which may include various other types of refractory seizures with secondary generalization together with progressive cognitive, behavioral, and psychiatric dysfunction. The hamartoma itself has been unequivocally shown to be intrinsically epileptogenic. Over the past 2 decades there has been considerable effort to develop neurosurgical techniques to treat the epileptic syndrome effectively as well as to improve the neurocognitive and behavioral outcome.

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.

Cognitive and neurological sequelae after stereoendoscopic disconnection of a hypothalamic hamartoma. A case study

Hypothalamic hamartomas (HH) are congenital malformations of the hypothalamus, often generating medically refractory gelastic seizures. There is great risk of progression to various complex partial and generalized seizures and of cognitive and behavioral deterioration. Hence, various surgical approaches have been introduced to resect or disconnect the HH from surrounding tissue, and stereoendoscopic disconnection has been advocated as one of the most lenient approaches to sessile HH embedded in the third ventricle. In fact, no long-term neurological or cognitive impairments have hitherto been reported after this procedure. Yet, unforeseen complications may arise in any surgical intervention on this region. We found serious deterioration of memory and reading skills by comprehensive neuropsychological assessments pre- and postoperatively in a child who, before surgery, was age-appropriate with respect to cognitive, emotional, and behavioral development. The child also contracted a permanent oculomotor paresis. Our results are discussed in light of previous relevant findings.

The evolution of treatment for hypothalamic hamartoma: a personal odyssey

The prognosis for patients with hypothalamic hamartoma has improved dramatically over the last 20 years, for 3 main reasons. First, because of improved understanding of the anatomy and pathophysiology of these varied lesions. Second, due to advances in brain imaging and refinements in microsurgery, including the anterior transcallosal interforniceal approach, endoscopic, and skull-base approaches. And third, because of increasing experience with stereotactic radiosurgery, interstitial radiotherapy, and radiofrequency lesioning. Patients with hypothalamic hamartoma should be managed in comprehensive epilepsy centers where the treatments are individualized and concentrated in the hands of surgeons who can perform the full range of surgery, including approaches to the third ventricle. Total seizure-freedom rates of 52% to 66% have been achieved with surgery.