Hypothalamic Hamartomas: Evolving Understanding and Management

Distinct gray matter and metabolic characteristics in hypothalamic hamartoma network with different semiology

OBJECTIVE

Hypothalamic hamartomas (HHs) are developmental malformations associated with focal epilepsy. We investigated the patterns of gray matter morphology and cerebral metabolism in individuals with HHs, with and without focal to bilateral tonic-clonic seizures (FBTCSs), aiming to clarify the accompanying network abnormalities.

METHODS

We analyzed magnetic resonance imaging (MRI) and fluorodeoxyglucose positron emission tomography (PET) data from 59 patients with HHs (28 with FBTCSs, 31 without), as well as MRI data from 30 healthy controls (HCs) and PET data from 45 HCs. We assessed gray matter voxel-based morphometry and quantitative analysis of cerebral glucose uptake in HH patients and controls, with age, sex, and total intracranial volume as covariates, and drew correlations with duration of epilepsy and seizure semiology and frequency.

RESULTS

Compared to HCs, HH patients had significantly increased gray matter volume (GMV) in the ipsilateral amygdala, piriform cortex, hypothalamus, and bilateral temporal cortices; patients with FBTCSs primarily showed increased GMV in the HH stalk, whereas those without FBTCSs showed increased GMV prominently in the amygdala. GMVs of amygdala and piriform cortex were greater and the ipsilateral midtemporal cortex was more hypometabolic the longer the duration of epilepsy and the greater the seizure frequency. No significant GMV or cerebral glucose uptake differences were found between HH patients with and without FBTCSs.

SIGNIFICANCE

HH-related epilepsy is a network disorder characterized by widespread abnormalities beyond the lesion. This highlights the importance of considering the whole network when formulating diagnosis and treatment plans.

Robot-assisted MRI-guided laser interstitial thermal therapy for a giant sessile hypothalamic hamartoma in an 8-year-old boy: illustrative case

BACKGROUND

Hypothalamic hamartoma (HH) is a nonneoplastic tumor associated with precocious puberty and gelastic seizures, characterized by uncontrolled, inappropriate laughter. Successful treatment can resolve symptoms, but medications are often ineffective, and surgical treatment is complicated by the deep brain location. Laser interstitial thermal therapy (LITT) has been shown to be a safe alternative, but it has been suggested that it may not be suitable for larger lesions due to the increased risk of postoperative perilesional edema.

OBSERVATIONS

The authors report the case of a giant sessile HH successfully treated with LITT. An 8-year-old male with a history of precocious puberty and refractory gelastic seizures presented for treatment of a giant HH first diagnosed in 2018. The authors performed robot-assisted stereotactic placement of a laser electrode and magnetic resonance imaging-guided ablation of the HH. He had no complications and has had a 90% seizure reduction as of 7 months postoperatively. They identified 4 studies describing LITT for giant HHs in the literature with conflicting results.

LESSONS

There have been limited reports of LITT for giant HHs. The authors demonstrate that this modality can be a safe, effective option for patients with large lesions. https://thejns.org/doi/10.3171/CASE24628.

MRgFUS disconnection surgery for hypothalamic hamartoma-related epilepsy: case report and literature review

BACKGROUND

Drug-resistant epilepsy (DRE) secondary to hypothalamic hamartoma (HH) often requires surgical resection or stereotactic radiosurgery, which frequently fail to provide satisfactory outcomes and are associated with severe side effects. Magnetic resonance-guided focused ultrasound (MRgFUS) may represent a minimally invasive surgical approach to HH by offering precise thermal ablation of sub-millimetric brain targets while sparing surrounding structures.

METHODS

We present the case of a 19-year-old man with HH-associated DRE, who was successfully treated with MRgFUS. The procedure resulted in effective ablation of the hypothalamic interface of the HH, disconnecting the epileptogenic lesion from the surrounding brain tissue. We also reviewed the literature on MRgFUS for DRE.

RESULTS

The patient experienced a complete resolution of seizures and significant improvements in social and occupational functioning over an 18-month follow-up period. No neurological, cognitive, or endocrinological adverse effects were observed.

CONCLUSION

Our case report and literature review suggest that MRgFUS may achieve adequate seizure control in DRE associated with HH without adverse effects. While MRgFUS shows promise for other forms of DRE, data remain preliminary, and some safety concerns persist. Further studies with long-term follow-up are warranted to better support the use of MRgFUS in DRE.

Lateralizing value of interictal epileptiform discharges and other parameters in hypothalamic hamartoma

OBJECTIVE

Hypothalamic hamartomas (HHs) are associated with pharmacoresistant epilepsy. Stereotactic radiofrequency thermocoagulation (SRT) shows promise as a disconnecting intervention. Although magnetic resonance imaging (MRI) is typically used to determine the attachment and intervention side, it presents challenges in cases of bilaterally attached HH, where the epileptogenic side is unclear. The lateralizing potential of electroclinical parameters in such cases remains uncertain. This retrospective study evaluates the lateralization value of specific parameters, particularly in patients with unilateral HH, to improve future diagnostics and treatment approaches for bilateral HH.

METHODS

Four lateralizing parameters-semiology, ictal electroencephalography (EEG), and interictal epileptiform discharges during awake (IEDsw) and sleep states (IEDss)-were assessed for correlation with HH attachment side using Spearman's ρ. We calculated areas under the curves (AUCs) and cutoffs for left and right IEDs prognostic lateralizing value, plotting differences between IEDsright and IEDsleft in a receiver-operating characteristic(ROC) curve to establish the required preponderance of unilateral IEDss to differentiate between left and right HHs. Binomial logistic regression was employed to predict the HH attachment side.

RESULTS

We included 25 patients (2-55 years of age) with mainly unilateral (n = 22) HHs who underwent SRT and presurgical evaluation. All parameters correlated with HH attachment side (semiology R = -.62, p = .005; ictal EEG R = .51, p = .047; IEDs R = .55, p = .018; IEDw, R = .61, p = .018). AUC values for right and left IEDs were .76 (p = .047) and .85 (p = .019), respectively, with cutoffs of .34 and .15. The AUC for "IEDsright-IEDsleft" was .98 (p = .0018) with a cutoff of .16. IEDss and semiology were significant predictors, achieving 88% correct lateralization.

SIGNIFICANCE

IEDss are promising biomarkers for HH lateralization in unilateral HH. The predominance of unilateral IEDss suggests ipsilateral HH. Even in cases with predominantly bilateral IEDss, a slight preponderance of unilateral IEDss can indicate the attachment side. In addition, combining IEDss and semiology provides a predictive model for HH lateralization.

Hypothalamic Hamartomas: A Narrative Review

Hypothalamic hamartomas (HH) are infrequent, non-neoplastic malformations of the hypothalamus with heterogeneous clinical features, with symptoms including gelastic seizures, central precocious puberty, and cognitive or behavioral deficits. This narrative review synthesizes current knowledge regarding the etiology, clinical manifestations, diagnostic advances, and therapeutic approaches for HH. Genetic insights highlight the role of postzygotic mosaicism and dysregulated Sonic Hedgehog signaling in HH development, emphasizing their relevance in potential therapeutic strategies. Diagnostic modalities such as MRI, PET, and SEEG are pivotal in identifying and characterizing HHs, enabling precise treatment planning. Therapeutic interventions span pharmacological, surgical, and neuromodulatory approaches. While surgical approaches, such as transcallosal resection or stereotactic radiosurgery, can offer considerable seizure control, newer modalities, such as laser interstitial laser thermal therapy (LITT) as well as stereotactic radiofrequency thermocoagulation, prioritize minimizing both cognitive and behavioral sequelae. The use of pharmacologic management and neuromodulation provides adjuvant benefits, specifically in drug-resistant epilepsy; despite progress, limitations still remain, including variability of outcomes and not enough long-term studies. This review underscores the need for multidisciplinary care and advanced research to optimize outcomes and improve the quality of life for patients with HH.

Outcome of Surgery for Hypothalamic Hamartoma-Related Epilepsy: A Systematic Review and Individual Participant Data Meta-Analysis

BACKGROUND AND OBJECTIVES

There is a paucity of data directly comparing the outcome of surgical techniques available for the treatment of hypothalamic hamartomas (HHs). This study aims to evaluate the safety and efficacy of commonly used surgical approaches in the treatment of HH-related epilepsy.

METHODS

A systematic review and individual participant data (IPD) meta-analysis was conducted. The PubMed, Embase, and Scopus online databases were searched without any date restrictions for original studies with more than 1 participant reporting on patients with HH-related epilepsy who underwent surgical treatment. Random-effects modeling was used to calculate the pooled proportions of seizure freedom (Engel I) at the last follow-up. IPD were used to perform mixed-effects logistic regression to identify predictors of seizure freedom and major postoperative complications.

RESULTS

Sixty-four studies were included, and IPD on 517 patients were obtained. The overall quality of evidence was low. After the index procedure, the pooled proportion of overall seizure freedom was 50.0% (95% CI 42.7%-57.4%), which increased to 64.5% (95% CI 57.2%-71.5%) after multiple treatments. Magnetic resonance-guided laser interstitial thermal therapy (MRgLITT) and radiofrequency thermocoagulation (RFTC) demonstrated the highest efficacy at the last follow-up, with seizure freedom rates of 74.5% (95% CI 66.8%-81.7%) and 78.5% (95% CI 71.6%-84.8%), respectively. Factors independently associated with a lower likelihood of seizure freedom included multiple seizure types (odds ratio [OR] 0.296, 95% CI 0.140-0.624, p = 0.001) and previous surgery (OR 0.418, 95% CI 0.198-0.884, p = 0.023). Stereotactic radiosurgery (SRS) was the safest approach, with a pooled proportion of major complications of 0.0% (95% CI 0.0%-1.4%). Only surgical technique emerged as an independent predictor of major complications, with SRS (OR 0.024, 95% CI 0.002-0.292, p = 0.004), RFTC (OR 0.133, 95% CI 0.026-0.692, p = 0.017), and MRgLITT (OR 0.234, 95% CI 0.056-0.968, p = 0.045) being associated with a lower likelihood of major complications.

DISCUSSION

MRgLITT and RFTC offer superior efficacy and safety compared with open microsurgery and should be considered as first-line options. Despite its lower efficacy, SRS is associated with few reported long-term complications, making it a viable alternative for select cases, such as small HHs with good baseline functioning. Direct comparisons between techniques are limited by short follow-up durations in RFTC and MRgLITT cohorts. Further large-scale, multicenter studies directly comparing these modalities are warranted.

Endoscopic endonasal resection of olfactory tract hamartoma for pediatric epilepsy

BACKGROUND

Non-hypothalamic glioneural hamartomas are rare entities known to cause medically refractory epilepsy. Olfactory bulb hamartomas, in particular, are exceptionally rare.

METHODS

We describe a case of an olfactory bulb hamartoma that was surgically resected at our institution. We also performed a literature review of all glioneural hamartomas and discuss the clinical presentation, diagnosis, and management of these lesions.

RESULTS

Herein, we present the unusual case of a typically developing 17-year-old boy with a near life-long history of drug-resistant epilepsy, found to have a 0.8 × 1.0 cm right olfactory bulb hamartoma. Endoscopic endonasal trans-cribriform resection of the lesion led to seizure freedom in the 6-month follow-up period (Engel class 1 outcome). Comprehensive literature review revealed only one other sporadic case, which was also successfully treated with total surgical resection.

CONCLUSIONS

Our case of an olfactory bulb hamartoma adds to the limited literature currently available, illustrating key clinical characteristics of these exceedingly rare lesions and outlining an effective, minimally invasive, and low-morbidity treatment strategy.

Genetic Insights Into Hypothalamic Hamartoma: Unraveling Somatic Variants

Objectives

Hypothalamic hamartomas (HHs) are rare developmental brain lesions associated with drug-resistant epilepsy and often subjected to epilepsy surgery. Brain somatic variants in genes affecting the Sonic hedgehog (Shh) and primary cilia signaling pathways have been implicated in approximately 50% of nonsyndromic HH cases. This study aims to characterize a new cohort of 9 HH cases and elucidate their genetic etiology.

Methods

We recruited 9 HH cases including 8 nonsyndromic cases of which 4 were type IV HH. Genomic DNA was extracted from peripheral blood and surgical brain tissues, and somatic variants were investigated using high-depth whole-exome sequencing.

Results

Pathogenic somatic variants in known HH genes (GLI3, OFD1, and PRKACA) were identified in 7 of the 9 cases. In addition, a 2-hit mutational event comprising a germline variant (predicted to impair kinase activity) and a somatic loss-of-heterozygosity was identified in TNK2, a gene encoding a brain-expressed tyrosine kinase.

Discussion

Our findings reinforce the role of somatic variants in Shh and cilia genes in HH cases while also shedding light on TNK2 as a potential novel disease-causing gene. This study emphasizes the increasing importance of brain mosaicism in epilepsy disorders and underscores the critical role of genetic diagnosis derived from resected brain tissue.

Magnetic Resonance-Guided Laser Interstitial Thermal Therapy in the Management of Hypothalamic Hamartomas: A Systematic Review and Meta-Analysis

OBJECTIVE

Magnetic resonance-guided laser interstitial thermal therapy (MRg-LITT) is a promising new technique to ablate epileptic foci in patients with hypothalamic hamartoma (HH). We aim to systematically synthesize all available evidence and determine the effectiveness of MRg-LITT in reducing seizures in patients with HH.

METHODS

We systematically searched MEDLINE (PubMed), Embase (Ovid), Scopus, and Google Scholar for all relevant articles. We used Open[Meta]Analyst to pool the number of seizure-free patients after MRg-LITT treatment in a random-effects model. Risk ratios were calculated, and subgroups were analyzed. Comprehensive meta-analysis was used to assess publication bias via funnel plots, Egger's regression test, and Begg's correlation test. This review complies with the Preferred Reporting Items for Systematic Review and Meta-Analyses guidelines.

RESULTS

After screening the titles, abstracts, and full texts, we included 17 articles in our meta-analysis, which revealed a 77.1% rate of seizure freedom (95% confidence interval 0.696-0.837, P<0.001), with moderate heterogeneity (I2=49.46%). Subgroup analysis by study design and sensitivity analyses excluding 1 study at a time did not impact the results substantially, and we found no evidence of publication bias. Adverse effects included electrolyte imbalances, weight gain, and transient neurologic disturbances.

CONCLUSIONS

MRg-LITT might be a feasible and effective technique for ablation of epileptic foci, leading to seizure freedom in a large proportion of patients with HH. However, there is a paucity of literature on the topic, and prospective clinical trials with larger number of participants comparing MRg-LITT to open surgery are needed.

A Comprehensive Review of Recent Trends in Surgical Approaches for Epilepsy Management

Epilepsy is a neurological disorder that affects millions of people worldwide, with a significant proportion of patients experiencing drug-resistant epilepsy, where seizures remain uncontrolled despite medical treatment. This review evaluates the latest surgical techniques for managing epilepsy, focusing on their effectiveness, safety, and the ongoing challenges that hinder their broader adoption. We explored various databases including PubMed, Google Scholar, and Cochrane Library to look for relevant literature using the following keywords: Epilepsy, Resective Surgery, Corpus Collectumy, and Antiepileptic Drugs. A total of 54 relevant articles were found and thoroughly explored. Recent advancements in surgical interventions include resective procedures such as anterior temporal lobectomy, corpus callosotomy, and hemispherectomy, which have been particularly effective in reducing seizures for specific types of epilepsy. Minimally invasive techniques, including laser interstitial thermal therapy and focused ultrasound, are increasingly being used, offering promising outcomes for certain patient groups. Additionally, neuromodulation methods such as deep brain stimulation, vagus nerve stimulation, and responsive neurostimulation provide alternative treatment options, especially for patients who are not suitable candidates for resective surgery. Despite these advancements, the full potential of epilepsy surgery is often underutilized due to various challenges. Inconsistent referral practices, a lack of standardized surgical protocols, and significant socioeconomic barriers continue to limit access to these procedures. Addressing these issues through improved referral processes, better education for healthcare providers and patients, and ensuring equitable access to advanced surgical treatments is crucial for optimizing patient outcomes. Future research should focus on overcoming these barriers and assessing long-term outcomes to further enhance the care of patients with epilepsy.

Surgical and radiosurgical treatment of hypothalamic hamartoma: The Italian experience between 2011 and 2021

OBJECTIVE

To investigate the Italian experience on the surgical and radiosurgical treatment of drug-resistant epilepsy due to hypothalamic hamartoma (HH) in the period 2011-2021 in six Italian epilepsy surgery centers, and to compare safety and efficacy profiles of the different techniques.

METHODS

We collected pseudo-anonymized patient's data with at least 12 months of follow-up. Surgical outcome was defined according to Engel classification of seizure outcome. Univariate analysis was performed to assess the risk of post-operative seizures, categorized in dichotomous variable as favorable and unfavorable; explanatory variables were considered. Mann-Whitney or Chi-squared test were used to assess the presence of an association between variables (p < 0.05).

RESULTS

Full presurgical and postoperative data about 42 patients from 6 epilepsy surgery centers were gathered. Engel class I was reached in the 65.8% and 66.6% of patients with gelastic and non-gelastic seizures, respectively. Other than daily non-gelastic seizures were associated with seizure freedom (p = 0.01), and the radiological type presented a trend toward significance (p = 0.12).

SIGNIFICANCE

Endoscopic disconnection and laser interstitial thermal therapy are effective in the treatment of HH-related epilepsy, with a tolerable safety profile. Both gelastic and non-gelastic seizures can be treated, also in patients with a long history of seizures.

PLAIN LANGUAGE SUMMARY

This study collected data about 42 patients with HH-related epilepsies. Endoscopic disconnection and laser therapy are both effective and safe in the treatment of hypothalamic hamartoma-related epilepsies.

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.

Clinical Features and Surgical Outcomes of Spinal Hamartomas: Surgical Treatment of 8 Patients

OBJECTIVE

Rarely do spinal hamartomas receive attention in the literature, and the majority of previous studies consist of case reports. The purpose of this report, then, is to provide a more accurate diagnosis and treatment of spinal hamartomas by presenting the clinical and surgical outcomes of 8 cases.

METHODS

The researchers conducted a retrospective analysis of the data for 8 individuals with spinal hamartomas. The 8 patients had undergone both preoperative and postoperative magnetic resonance imaging (MRI) and went through surgery. Radiologic and pathologic criteria were applied to diagnose the spinal hamartomas. The Modified McCormick classification system was used to evaluate neurologic function in these patients.

RESULTS

Among the 8 patients, 6 were male and 2 were female, with an average age of 37.4 years. The typical duration of symptoms was 14.5 months. During surgery, all lesions were well-defined and located in the bone marrow. Gross total resection (GTR) was achieved in 6 cases, and the anatomical plane was clearly delineated, and subtotal resection (STR) was achieved in 2 cases. None of the patients took postoperative radiotherapy. 14.5 months was the average follow-up period during this time, and MRI did not observe the recurrence or regeneration of residual tumors. The McCormick grade was improved in 7 patients and remained stable in 1 patient.

CONCLUSIONS

Spinal hamartomas are benign, but they are clinically progressive lesions. Pathology is the basis of accurate diagnosis, and complete preoperative evaluation is crucial for providing suitable treatment and prognosis.

Neural network mapping of gelastic behavior in children with hypothalamus hamartoma

BACKGROUND

Hypothalamus hamartomas (HHs) are rare, congenital, tumor-like, and nonprogressive malformations resulting in drug-resistant epilepsy, mainly affecting children. Gelastic seizures (GS) are an early hallmark of epilepsy with HH. The aim of this study was to explore the disease progression and the underlying physiopathological mechanisms of pathological laughter in HH.

METHODS

We obtained clinical information and metabolic images of 56 HH patients and utilized ictal semiology evaluation to stratify the specimens into GS-only, GS-plus, and no-GS subgroups and then applied contrasted trajectories inference (cTI) to calculate the pseudotime value and evaluate GS progression. Ordinal logistic regression was performed to identify neuroimaging-clinical predictors of GS, and then voxelwise lesion network-symptom mapping (LNSM) was applied to explore GS-associated brain regions.

RESULTS

cTI inferred the specific metabolism trajectories of GS progression and revealed increased complexity from GS to other seizure types. This was further validated via actual disease duration (Pearson R = 0.532, P = 0.028). Male sex [odds ratio (OR) = 2.611, P = 0.013], low age at seizure onset (OR = 0.361, P = 0.005), high normalized HH metabolism (OR =  - 1.971, P = 0.037) and severe seizure burden (OR =  - 0.006, P = 0.032) were significant neuroimaging clinical predictors. LNSM revealed that the dysfunctional cortico-subcortico-cerebellar network of GS and the somatosensory cortex (S1) represented a negative correlation.

CONCLUSIONS

This study sheds light on the clinical characteristics and progression of GS in children with HH. We identified distinct subtypes of GS and demonstrated the involvement of specific brain regions at the cortical-subcortical-cerebellar level. These valuable results contribute to our understanding of the neural correlates of GS.

Intraoperative changes in large-scale thalamic circuitry following laser ablation of hypothalamic hamartomas

BACKGROUND AND OBJECTIVES

Gelastic seizures due to hypothalamic hamartomas (HH) are challenging to treat, in part due to an incomplete understanding of seizure propagation pathways. Although magnetic resonance imaging-guided laser interstitial thermal therapy (MRgLITT) is a promising intervention to disconnect HH from ictal propagation networks, the optimal site of ablation to achieve seizure freedom is not known. In this study, we investigated intraoperative post-ablation changes in resting-state functional connectivity to identify large-scale networks associated with successful disconnection of HH.

METHODS

Children who underwent MRgLITT for HH at two institutions were consecutively recruited and followed for a minimum of one year. Seizure freedom was defined as Engel score of 1A at the last available follow-up. Immediate pre- and post- ablation resting-state functional MRI scans were acquired while maintaining a constant depth of general anesthetic. Multivariable generalized linear models were used to identify intraoperative changes in large-scale connectivity associated with seizure outcomes.

RESULTS

Twelve patients underwent MRgLITT for HH, five of whom were seizure-free at their last follow-up. Intraprocedural changes in thalamocortical circuitry involving the anterior cingulate cortex were associated with seizure-freedom. Children who were seizure-free demonstrated an increase and decrease in connectivity to the pregenual and dorsal anterior cingulate cortices, respectively. In addition, children who became seizure-free demonstrated increased thalamic connectivity to the periaqueductal gray immediately following MRgLITT.

DISCUSSION

Successful disconnection of HH is associated with intraoperative, large-scale changes in thalamocortical connectivity. These changes provide novel insights into the large-scale basis of gelastic seizures and may represent intraoperative biomarkers of treatment success.

Infantile Hypothalamic Hamartoma: A Rare Presentation of Isolated Obesity

Hypothalamic hamartomas (HHs) are rare, benign brain tumors or lesions of the hypothalamus that are predominantly identified in cases of epilepsy and central precocious puberty (CPP), whereas isolated manifestations of infantile obesity are atypical. We herein report an 8-month-old boy with severe obesity (Kaup index 26.4 [>100th percentile]) and uncontrollable hyperphagia. His growth chart demonstrated remarkable weight gain that exceeded the length gain in magnitude. Brain magnetic resonance imaging identified a lesion consistent with HH. There were no episodes or clinical findings of epilepsy, CPP, or Cushing disease. Hypothalamic obesity should be considered in the diagnosis even in infants with excessive weight gain due to overeating.

Sporadic Spinal Hamartoma in Adults: A Rare Pathologic Entity

BACKGROUND

Sporadic spinal hamartomas in adults are extremely rare tumor-like lesions, without defined guidelines of treatment. The aim of this study is to investigate the peculiar features of this pathologic entity to support a more accurate diagnosis and management.

METHODS

A comprehensive and detailed literature review of sporadic spinal hamartomas in adults, including a personal case, was performed. Demographic (sex and age), clinical (presenting symptoms), radiologic and pathologic (size, localization, dural and spinal cord relationship of lesion) features, as well as treatment (time to surgery, extent of resection, perioperative and postoperative complications) and outcome (clinical) data were analyzed.

RESULTS

Seven studies, including 7 patients, were eligible for the review. A personal case was also added. Sporadic adult spinal hamartomas equally affect males and females, in a range of age from 18 to 75 years; sensory radicular deficits were detected in all patients at clinical onset; thoracic segment (4/8) of the spine and intradural compartment (6/8) were most involved. All patients underwent surgery and just one experimented postoperative complication; gross total resection was achieved in only 3 patients, mainly in an extradural localization; clinical improvement at last follow-up was reported in all but 1 patient.

CONCLUSIONS

Spinal hamartomas in adults may sometimes account for progressive worsening of neurologic symptoms and lead to potentially irreversible neurologic deficit; therefore, prompt and adequate diagnosis and treatment are mandatory. Surgical resection represents the only curative treatment and is indicated for symptomatic lesions to achieve neurologic symptoms restoration or arrest/prevent their progressive deterioration.

[Hypothalamic hamartoma dissection using focused ultrasound under MRI control. The first successful experience in Russia]

Treatment of motor disorders by MRI-guided focused ultrasound is an alternative to neuro- and radiosurgery such as stereotactic radiofrequency ablation and thalamotomy with a gamma knife. However, safety, efficacy and feasibility of this technology for intracranial neoplasms are still unclear. The authors report successful hypothalamic hamartoma dissection by MRI-guided focused ultrasound in a 32-year-old woman with drug-resistant gelastic epilepsy and violent laughter and crying attacks. Magnetic resonance imaging revealed type II hypothalamic hamartoma. The last one was detached from surrounding brain tissue by MRI-guided focused ultrasound without side effects. Symptoms regressed immediately after surgery. No laughter and crying attacks were observed throughout 6-month follow-up.

No More Tears: Surgical Options and Outcomes in Hypothalamic Hamartomas

Long Term Outcome After Surgical Treatment for Hypothalamic Hamartoma Kulkarni N, Nageotte RA, Klamer BG, Rekate HL, Bristol RE, Scharnweber T, Bobrowitz M, Kerrigan JF. Epilepsy Res . 2023;195:107186. doi:10.1016/j.eplepsyres.2023.107186 . PMID: 37454523 Purpose: To determine long-term outcome for seizure control and clinical predictors for seizure freedom in patients undergoing surgical treatment for epilepsy associated with hypothalamic hamartoma (HH). Methods: 155 patients underwent surgical treatment for HHs and treatment-resistant epilepsy at one center (Barrow Neurological Institute at St. Joseph’s Hospital and Medical Center, Phoenix, Arizona, USA) between February 2003 and June 2010. Data collection included medical record review and direct follow-up interviews to determine seizure outcome. Statistical analysis included descriptive summaries of patient characteristics and time-to-event analysis for seizure freedom. Results: Long-term survival with follow-up of at least five years since first surgical treatment was available for 108 patients (69.7% of the treatment cohort). The surgical approach for first HH intervention consisted of transventricular endoscopic resection (n = 57; 52.8%), transcallosal interforniceal resection (n = 35; 32.4%), pterional resection (n = 7; 6.5%), and gamma knife radiosurgery (n = 9; 8.3%). Multiple surgical procedures were required for 39 patients (36.1%). There were 10 known deaths from all causes in the treatment cohort (6.5%). Of these, one (0.6%) was related to immediate complications of HH surgery, three (1.9%) were attributed to Sudden Unexpected Death in Epileptic Persons (SUDEP), and one (0.6%) to complications of status epilepticus. For surviving patients with long-term follow-up, 55 (50.9%) were seizure-free for all seizure types. Univariable analysis showed that seizure-freedom was related to 1) absence of a pre-operative history for central precocious puberty (p = 0.01), and 2) higher percentage of HH lesion disconnection after surgery (p = 0.047). Kaplan-Meier survival analysis shows that long-term seizure outcome following HH surgery is comparable to short-term results. Summary: These uncontrolled observational results show that long-term seizure control following HH surgical treatment is comparable to other forms of epilepsy surgery. Late relapse (at least one year after surgery) and SUDEP do occur, but in a relatively small number of treated patients. These results inform clinical practice and serve as a comparable benchmark for newer technologies for HH surgery, such as magnetic resonance imaging-guided laser interstitial thermal therapy, where long-term outcome results are not yet available.

Epilepsy Surgery in Patients With Hypothalamic Hamartomas—Population-Based Two-Year and Long-Term Outcomes Hahne O, Rydenhag B, Tranberg AE, Kristjánsdóttir R, Nilsson D, Olsson I, Hallböök T. Eur J Paediatr Neurol . 2023;46:24-29. doi:10.1016/j.ejpn.2023.06.004 . PMID: 37385151 Objective: Hypothalamic hamartomas are benign lesions associated with drug resistant epilepsy. Surgical treatment has become an increasingly utilised approach with promising results. This study aims to evaluate seizure outcome and complications after surgery in a population-based series of patients with intractable epilepsy and hypothalamic hamartoma. Methods: All patients with hypothalamic hamartoma treated with epilepsy surgery in Sweden since 1995 with at least two years of follow-up were included. Preoperative, two-, five- and ten-year prospective longitudinal data were collected from The Swedish National Epilepsy Surgery Register. Data included seizure types and frequency, duration of epilepsy, clinical characteristics, neurological deficits, cognitive level and complications. In a subgroup from Gothenburg, we also analysed data not included in the register such as classification of hamartomas, surgical procedures and gelastic seizures. Results: Eighteen patients were operated on during the period 1995-2020. The median age at epilepsy onset was 6 months and age at surgery 13 years. Four were seizure free and another four had ≥75% reduction in seizure frequency at the two-year follow-up. Two of the 13 patients with a long-term follow-up (five or ten years) were seizure-free and four had ≥75% reduction in seizure frequency. Three had an increased seizure frequency. No major complications were seen. Five had minor complications. In the Gothenburg subgroup all had open pterional disconnection or intraventricular endoscopic disconnection. Six of 12 were free from gelastic seizures at the two-year follow-up and six of eight at the long-term follow-up. Conclusion: This study supports surgical treatment of hypothalamic hamartomas as a safe method with a low risk of permanent complications. The seizure reduction seems to be persistent over time.

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.

Seizure outcomes and safety profiles of surgical options for epilepsy associated to hypothalamic hamartomas. A systematic review and meta-analysis

PURPOSE

Several surgical options are available for treating hypothalamic hamartoma-related epilepsy but their respective efficacy and safety profiles are poorly defined.

METHODS

A literature search identified English-language articles reporting series of patients (minimum 3 patients with a follow-up ≥12 months) operated on by either microsurgery, endoscopic surgery, radiosurgery, radiofrequency thermocoagulation or laser interstitial thermal therapy for hypothalamic hamartoma-related epilepsy. The unit of analysis was each selected study. Pooled rates of seizure freedom and of neurological and endocrinological complications were analyzed using meta-analysis to calculate both fixed and random effects. The results of meta-analyses were compared.

RESULTS

Thirty-nine studies were included. There were 568 and 514 participants for seizure outcome and complication analyses, respectively. The pairwise comparison showed that: i) the proportion of seizure-free cases was significantly lower for radiosurgery as compared to microsurgery, radiofrequency thermocoagulation and laser ablation, and significantly lower for endoscopic surgery as compared to radiofrequency thermocoagulation; ii) the proportion of permanent hypothalamic dysfunction was significantly higher for microsurgery as compared to all other techniques, and significantly lower for endoscopic surgery as compared to radiofrequency thermocoagulation and laser ablation; iii) the incidence of permanent neurological disorders was significantly higher for microsurgery as compared to endoscopic surgery, radiosurgery and radiofrequency thermocoagulation, and significantly lower for radiosurgery as compared to laser ablation.

CONCLUSIONS

Minimally invasive surgical techniques, including endoscopic surgery, radiofrequency thermocoagulation and laser ablation, represent an acceptable compromise between efficacy and safety in the treatment of hypothalamic hamartoma-related epilepsy. Microsurgery and radiosurgery should be considered in carefully selected cases.

Long term outcome after surgical treatment for hypothalamic hamartoma

PURPOSE

To determine long-term outcome for seizure control and clinical predictors for seizure freedom in patients undergoing surgical treatment for epilepsy associated with hypothalamic hamartoma (HH).

METHODS

155 patients underwent surgical treatment for HHs and treatment-resistant epilepsy at one center (Barrow Neurological Institute at St. Joseph's Hospital and Medical Center, Phoenix, Arizona, USA) between February 2003 and June 2010. Data collection included medical record review and direct follow-up interviews to determine seizure outcome. Statistical analysis included descriptive summaries of patient characteristics and time-to-event analysis for seizure freedom.

RESULTS

Long-term survival with follow-up of at least five years since first surgical treatment was available for 108 patients (69.7% of the treatment cohort). The surgical approach for first HH intervention consisted of transventricular endoscopic resection (n = 57; 52.8%), transcallosal interforniceal resection (n = 35; 32.4%), pterional resection (n = 7; 6.5%), and gamma knife radiosurgery (n = 9; 8.3%). Multiple surgical procedures were required for 39 patients (36.1%). There were 10 known deaths from all causes in the treatment cohort (6.5%). Of these, one (0.6%) was related to immediate complications of HH surgery, three (1.9%) were attributed to Sudden Unexpected Death in Epileptic Persons (SUDEP), and one (0.6%) to complications of status epilepticus. For surviving patients with long-term follow-up, 55 (50.9%) were seizure-free for all seizure types. Univariable analysis showed that seizure-freedom was related to 1) absence of a pre-operative history for central precocious puberty (p = 0.01), and 2) higher percentage of HH lesion disconnection after surgery (p = 0.047). Kaplan-Meier survival analysis shows that long-term seizure outcome following HH surgery is comparable to short-term results.

SUMMARY

These uncontrolled observational results show that long-term seizure control following HH surgical treatment is comparable to other forms of epilepsy surgery. Late relapse (at least one year after surgery) and SUDEP do occur, but in a relatively small number of treated patients. These results inform clinical practice and serve as a comparable benchmark for newer technologies for HH surgery, such as magnetic resonance imaging-guided laser interstitial thermal therapy, where long-term outcome results are not yet available.

Brain mosaicism of hedgehog signalling and other cilia genes in hypothalamic hamartoma

Hypothalamic hamartoma (HH) is a rare benign developmental brain lesion commonly associated with a well characterized epilepsy phenotype. Most individuals with HH are non-syndromic without additional developmental anomalies nor a family history of disease. Nonetheless, HH is a feature of Pallister-Hall (PHS) and Oro-Facial-Digital Type VI (OFD VI) syndromes, both characterized by additional developmental anomalies. Initial genetic of analysis HH began with syndromic HH, where germline inherited or de novo variants in GLI3, encoding a central transcription factor in the sonic hedgehog (Shh) signalling pathway, were identified in most individuals with PHS. Following these discoveries in syndromic HH, the hypothesis that post-zygotic mosaicism in related genes may underly non-syndromic HH was tested. We discuss the identified mosaic variants within individuals with non-syndromic HH, review the analytical methodologies and diagnostic yields, and explore understanding of the functional role of the implicated genes with respect to Shh signalling, and cilia development and function. We also outline future challenges in studying non-syndromic HH and suggest potential novel strategies to interrogate brain mosaicism in HH.

Clinical Presentation and Management of Hypothalamic Hamartomas: A Systematic Review of the Literature

Hypothalamic hamartomas (HHs) are composed of abnormally distributed but cytologically normal cellular elements. This disease typically manifests in infancy with gelastic seizures characterized by outbursts of mechanical laughter (mirthless laughter), altered or retained consciousness, refractory to antiepileptic, and later progresses to behavioral and cognitive disturbances and secondary seizure types. A systematic review of the literature on the clinical presentation and management of HHs. A literature search was carried out in electronic databases such as PubMed, COCHRANE, SCOPUS, ScienceDirect, which included the studies reported on “hypothalamic,” “hamartoma,” and “epilepsy,” as well as the outcome with full texts in English. Letters, case reports, reviews, preclinical studies, conference proceedings, protocols, and nonhuman studies were excluded. Duplicates were removed in EndNote X7, and titles and abstracts of all listed articles were scanned. Data analysis of all included studies indicates that smaller lesions result in better outcomes and stereotactic laser ablative procedures have the highest Engel class I outcome percentage. Delalande type II lesions are much more common (n=201) followed by type III (n = 182), IV (n = 71), and I (n = 50). Stereotactic laser ablation is safe for large lesions. HHs can be treated safely when they are small. Therefore, early identification and intervention play a major role. This also prevents the seizure progression, leading to morbidity. SLA has fewer complications and increased seizure-free survival compared to other modalities of treatment.

Advances in hypothalamic hamartoma research over the past 30 years (1992-2021): a bibliometric analysis

Background

Hypothalamic hamartoma (HH) is a rare intracranial disease whose manifestations include gelastic seizures and precocious puberty. The diagnosis and treatment of HH have changed substantially over the past three decades as medical care has improved. Bibliometrics can reveal the evolution and development of a scientific field.

Methods

Documents on HH were retrieved from the Web of Science Core Collection (WoSCC) database on September 8, 2022. The search terms were as follows: "hypothalamic hamartoma" or "hamartoma of the hypothalamus" or "hypothalamic hamartomas." The types of documents were restricted to articles, case reports, and reviews. VOSviewer, CiteSpace, and the R package "bibliometrix" were used for a bibliometric analysis.

Results

A total of 667 independent documents on HH were obtained from the WoSCC database. The most common types of documents were articles (n = 498, 75%) and reviews (n = 103, 15%). The number of annual publications fluctuated but showed an upward trend overall, and the annual growth rate was 6.85%. The cumulative publication data indicated that the most influential journals in the HH field include Epilepsia, Epileptic Disorders, Child's Nervous System, Neurosurgery, and the Journal of Neurosurgery. Kerrigan JF, Ng YT, Rekate HL, Regis J, and Kameyama S were among the most prominent authors in the field of HH, with numerous publications and citations. American research institutions, especially the Barrow Neurological Institute, occupied a pivotal position in HH research. Other countries and institutions were catching up and producing considerable research results. Research on HH has steadily switched its emphasis from Pallister-Hall syndrome (PHS) and precocious puberty to epilepsy and new diagnostic and therapeutic techniques, including Gamma Knife, laser ablation, and interstitial thermal therapy.

Conclusion

HH remains a special neurological disease with significant research prospects. The development of novel technologies, including MRI-guided laser-induced thermal therapy (MRg-LiTT) and stereotactic radiofrequency thermocoagulation (RF-TC), has enabled the efficient treatment of gelastic seizures in HH while minimizing the risks associated with craniotomies. Through bibliometric analysis, this study points out the direction for future HH research.

Adult-onset hypothalamic hamartoma: origin of epilepsy?

BACKGROUND

Hypothalamic hamartoma (HH) is a congenital non-progressive lesion of hypothalamus during fetal development. Mass-like lesions in different anatomical locations often develop a variously disabling course presenting with cognitive decline, psychiatric symptoms, as well as multiple seizure types. As a rare disease, HH is relatively common in infants and children, but it is extremely rare in adults.

CASE PRESENTATION

We reported a case of adult-onset hypothalamic hamartoma, and summarized and analyzed relevant reports and studies of HH worldwide. The patient had clinical manifestations characterized by multiple seizure forms. After stereotactic radiofrequency thermocoagulation and drug treatment, the condition was effectively controlled. The patient was followed up till October 2022, with no recurrence of seizures.

CONCLUSIONS

Epilepsy caused by HH can resemble that of temporal lobe seizures, as HH forms a complex epileptogenic network with other regions of the brain through anatomical and functional connections. Early treatment of HH can provide better control of the symptoms of epilepsy, and patients with longer disease courses may have more complications.

Hypothalamic hamartoma: a cause of precocious puberty

Hypothalamic hamartomas are uncommon congenital malformations that present as precocious puberty, gelastic seizures and/or psychiatric disorders. Characteristic changes in MRI scans lead to a diagnosis. Treatment may include surgery or gonadotropin-releasing hormone agonists (GnRHa) depending on clinical manifestations.Here, we describe a case of hypothalamic hamartoma diagnosed in a girl in middle childhood, who presented with early development of secondary sexual characteristics. Physical examination, hormonal study, bone age and pelvic ultrasound findings were consistent with those of precocious puberty. The investigation also included a brain MRI scan, which revealed a small nodule with regular limits in the left hypothalamic region/tuber cinereum. GnRHa treatment and neurosurgical follow-ups were initiated promptly. The patient showed a reversal of secondary sexual characteristics and stable hamartoma size. This case illustrates the importance of brain MRI scans as part of the assessment of suspected precocious puberty because clinical features do not identify patients with an underlying pathology.

Anatomical features decide the atypical seizure manifestation of parahypothalamic hamartomas

Background

The intrahypothalamic phenotype of hypothalamic hamartomas (HH) is associated with epilepsy, and the parahypothalamic phenotype usually leads to central precocious puberty but not neurological comorbidities or seizures. No study has confirmed the pathological role of parahypothalamic hamartomas in epileptogenesis, and the underlying mechanism is yet to be elucidated.

Objective

We aimed to investigate whether parahypothalamic hamartomas are intrinsically epileptogenic and elucidate the underlying pathway of epileptogenesis.

Methods

We reviewed 92 patients with HH-related epilepsy, categorized them by the classification system of Delalande and Fohlen, and further classified Type I (corresponding to parahypothalamic HH) into the following three groups based on the relationship between the lesion and mammillary bodies (MB): entirely invaded (Group 1), partially connected (Group 2), and not connected at all (Group 3). We examined different anatomical features with their relationship to clinical manifestations. Stereoelectroencephalography (SEEG) was implanted in both HH and extra-HH cortices in different groups to identify the epileptogenic zone. Corticocortical evoked potentials (CCEPs) were also used to determine the pathological correlation among different regions to determine the related epileptogenic network.

Results

A total of 13 patients presented with parahypothalamic HH and 10 (76.9%) presented with non-GS only, with late-onset age and normal cognitive development, which is different from classical clinical features. SEEG showed that HH is intrinsically epileptogenic in MB-involved parahypothalamic groups. No statistical difference was found in onset age (p = 0.213), and lesions horizontally oriented from the tuber cinereum without connection to MB were not involved in seizure genesis. CCEP indicated a pathological connection among HH, middle cingulate cortex, and insular cortex.

Conclusion

The parahypothalamic HH can also cause epilepsy and is different from classic HH-related seizures, by non-GS only with the late-onset age and normal cognitive development. MB is proven to be related to non-GS by the mamillo-cingulate-cortex pathway.