Classification of hypothalamic hamartoma and prognostic factors for surgical outcome

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.

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.

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.

[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.

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.

Stereotactic radiosurgery as the initial management option for small-volume hypothalamic hamartomas with intractable epilepsy: a 35-year institutional experience and systematic review

OBJECTIVE

Young patients with hypothalamic hamartomas (HHs) often present with intractable epilepsy. Currently there are no established management guidelines for HH. The authors retrospectively reviewed their single-institution experience to delineate the role of stereotactic radiosurgery (SRS).

METHODS

Seven patients with HHs (4 females; median age 13.7 years, range 2.5-25 years) with no prior resection underwent SRS between 1987 and 2022. The clinical history, epilepsy profile, radiographic findings, and neurological outcomes were characterized. HH topographical types were classified according to the Régis classification. Outcome measures included Engel seizure classification, HH response, and the need for additional surgical interventions.

RESULTS

All patients had Engel class IV epilepsy. A Leksell Gamma Knife was used to deliver a median margin dose of 18 Gy (range 16-20 Gy) to a median hamartoma volume of 0.37 cm3 (range 0.20-0.89 cm3). Seizure reduction was confirmed in 6 patients, and 2 patients had regression of their hamartoma. Two patients underwent resection and/or laser interstitial thermal therapy after SRS. At follow-up, 1 patient was seizure free, 4 patients achieved Engel class II, 1 patient had Engel class III, and 1 patient had Engel class IV seizure outcomes.

CONCLUSIONS

SRS as the initial management option for HH was associated with a low risk of adverse effects. In this institutional series reviewing small-volume HHs treated with SRS, no adverse radiation effect was detected, and the majority of patients experienced seizure reduction. SRS should be considered as the first-line treatment for seizure control in patients with small-volume HHs.

A clinical evaluation of gelastic and dacrystic seizures: a multicenter study

BACKGROUND

Gelastic seizures are extremely rare, short-lasting, unprovoked, and uncontrollable laughing attacks. We conducted this retrospective evaluation to determine whether these symptoms, manifesting in different forms, such as cheerful laughter, laughing, smiling, and sobbing had any value in terms of etiology or localization.

METHODS

A total of 31 patients who exhibited bouts of laughing or crying and who were under follow-up between 2000 and 2019 at tertiary epilepsy centers were included in the study. Laughing seizures were divided into three groups in terms of semiology (i.e., laughter with mirth, laughter without mirth, and smile). Dacrystic seizures were accompanied by some gelastic seizures and were divided into two groups in terms of semiology (i.e., weeping loudly [motor and voice-sobbing] and crying).

RESULTS

Of the 27 patients with laughing seizures, 12 had seizures that manifested with smiling, 7 had seizures that manifested with laughing and mirth, and 8 had seizures that manifested with laughter without mirth. Dacrystic-gelastic seizures were observed in four patients, among whom 2 patients had crying and laughter without mirth and 2 patients had weeping loudly and laughter without mirth episodes.

CONCLUSION

Gelastic and dacrystic seizures often suggest hypothalamic hamartomas, in the literature. This rare ictal behavior can originate from different cortical locations and lesions of a different nature. However, we found that gelastic seizures with smiling were a more homogenous group with regard to location in the temporal lobe, which we aimed to show by evaluating the patients included in this study.

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.

Management of Central Precocious Puberty in Children with Hypothalamic Hamartoma

Hypothalamic hamartoma (HH) is a rare, congenital, and benign lesion of the tuber cinereum, typically presenting with central precocious puberty (CPP), gelastic seizure, and developmental delay. This study aimed to investigate CPP in HH patients and compare clinical features between before and after gonadotropin-releasing hormone (GnRH) agonist treatment. A total of 30 HH patients under 18 years of age who visited Severance Children’s Hospital between January 2005 and May 2020 were retrospectively reviewed. Fourteen patients were male (46.7%) and sixteen (53.3%) were female, with a mean age at diagnosis was4.2 ± 2.9 years. During follow-up, 24 patients (80.0%) were diagnosed with CPP, 15 patients (50.0%) had gelastic seizure, and 13 patients (43.3%) had developmental delay. The gelastic seizure was significantly associated with sessile type HH rather than pedunculated type HH (85.7% vs. 18.8%, p = 0.001). After GnRH agonist treatment, discrepancies between bone age and chronological age decreased (3.3 ± 1.3 years to 2.0 ± 1.7 years, p = 0.002). Additionally, height standard deviation score for bone age was increased, and predicted adult height increased significantly in females, while males showed an increasing trend. Clinical symptoms of HH were closely associated with the location of HH, and GnRH agonist treatment was safe and effective in the management of CPP caused by HH.

Stereoelectroencephalography-guided radiofrequency thermocoagulation for hypothalamic hamartoma: Electroclinical patterns and the relationship with surgical prognosis

BACKGROUND

Radiofrequency thermocoagulation (RFTC) guided by stereo-electroencephalography (SEEG) has been proved to be a safe method to reduce seizure frequency in patients with drug-resistant epilepsy. However, there are few reports addressing the value and safety of this procedure in hypothalamic hamartoma (HH).

OBJECTIVE

To present the results of our experience using SEEG-guided RFTC in HH patients with drug-resistant epilepsy, and identify outcome predictors.

METHODS

We retrospectively reviewed the clinical and surgical characteristics of 27 HH-related patients with epilepsy in our center between 2015 and 2019. All patients underwent invasive recordings with SEEG before RFTC was performed. We reported surgical outcome predictors and postoperative follow-up concerning safety and efficacy (mean follow-up, 27.3 months; range, 12-63). Surgical strategy was also analyzed.

RESULTS

Nineteen patients (70.4%) achieved Engel's class I outcome, while 4 patients (14.8%) did not show significant improvement. Of all observed seizures, two different onset patterns of intracranial electrophysiology recorded by SEEG were observed. Patients presented with focal low-voltage fast activity were more likely to obtain seizure freedom (p = 0.045), while classification (p = 0.478), volume (p = 0.546), history of resection (p = 0.713), seizure types (p = 0.859), or seizure duration (p = 0.415) showed no significant effect on the outcome. Weight gain was the most common long-term complication (18.5%).

CONCLUSION

The SEEG can guide the ablation of HH and serve as an important factor to predict favorable seizure outcomes. Radiofrequency thermocoagulation guided by SEEG can offer a minimally invasive and low-risk surgical approach with excellent outcomes. Disconnecting the attachment of HH should be the appropriate strategy to obtain the best seizure outcome.

Epileptic hypothalamic hamartomas impact of topography on clinical presentation and radiosurgical outcome

INTRODUCTION

Evidence exists for the role of the hypothalamic hamartoma's topography as a determinant for the clinical presentation. How the hamartoma relation to the hypothalamic structures can make clinical presentations, severity and surgery outcomes different from patient to patient is largely unknown. Our aim was to analyze the effect of fine anatomical topography on clinical spectrum and radiosurgery outcome.

METHODS

Forty-eight epileptic patients with hypothalamic hamartoma were treated by Gamma Knife Surgery and were reviewed for fine topography and morphology using magnetic resonance neuroimaging. We evaluated different topographic patterns; contact to prominent structures (the mammillary body, tuber cinereum and pituitary stalk), the degree of involvement within sagittally-oriented regions, (mammillary, tuberal, and supra optic) coronally-oriented zones (periventricular, medial, and lateral), lesion dimensions (length, width, and height),and volumes (total, intra-hypothalamic, and extra-hypothalamic volumes). This data were statistically analysed for correlation with all clinical variables and epilepsy surgery outcome. We reviewed all the classification protocols in the literature.

RESULTS

Focal onset impaired awareness seizures started at an earlier age of onset with larger hypothalamic hamartoma volume and dimensions. Lateral extension within the hypothalamus was associated with more severe epilepsy, higher seizure frequency, more severe psychiatric comorbidity, hetero-aggression, hyperkinesia, and school difficulties. Presence of precocious puberty was positively correlated to anterior-posterior extension; tuberal region involvement, hypothalamic hamartoma volume, and type III-VI. Larger hypothalamic hamartoma presented precocious puberty at an earlier age of onset. After Gamma Knife Surgery, epilepsy outcome was better and rapid when lesion is smaller. Post-radiosurgical transient increased seizures were present when the mammillary region was more involved.

CONCLUSION

Clinical presentation of epileptic hypothalamic hamartoma is significantly affected by fine topography patterns and invaded hypothalamic areas. Gamma Knife Radiosurgery effect is better and rapid in smaller hamartoma (Type I-III) and seizure outcome was not affected by the invaded hypothalamic areas.

Stereotactic radiofrequency thermocoagulation and resective surgery for patients with hypothalamic hamartoma

OBJECTIVE

In this study, the authors compared the efficacy and safety of stereotactic radiofrequency thermocoagulation (SRT) and resective surgery (RS) for patients with hypothalamic hamartoma (HH).

METHODS

The authors included all patients with HHs who were treated by SRT or hamartoma resection. Seizure outcomes were assessed by blinded observers according to the International League Against Epilepsy (ILAE) classification. Favorable seizure outcomes were defined as ILAE classes 1 and 2, and unfavorable seizure outcomes were defined as ILAE classes 3-6.

RESULTS

Twenty-nine patients who underwent SRT or RS met the inclusion criteria; 3 were excluded because they had completed less than 12 months of follow-up. Most of the patients (20 of 26; 76.9%) had small HHs (i.e., maximum HH diameter less than 20 mm). The patients' follow-up time ranged from 12 to 66 months (median 60 months). At the last follow-up, favorable outcomes were observed in 9 patients (69.2%) who had undergone SRT and 10 patients (76.9%) who had undergone HH resection. No significant difference was found in seizure outcomes between SRT and RS recipients. Patients with giant HHs were more likely than patients with smaller tumors to undergo multiple resections (p = 0.043, univariate logistic regression; significant). However, no significant difference was found between SRT and RS recipients in terms of the number of procedures per patient. SRT recipients had fewer and less-severe adverse events than RS recipients.

CONCLUSIONS

For patients with small HHs, SRT provides similar seizure outcomes to RS with a less invasive procedure. Patients who underwent SRT experienced fewer and lighter adverse effects than patients who had RS. Patients with giant HHs were more likely to undergo multiple HH resections.

Is surgery effective for treating hypothalamic hamartoma causing isolated central precocious puberty? A systematic review

The aim of this review was to determine the role of surgery in treating hypothalamic hamartoma (HH) causing isolated central precocious puberty (CPP). Literature review was done according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Patients with isolated CPP due to HH, managed with surgical resection, were included. We found 33 studies, reporting 103 patients (76 pedunculated, 27 sessile). Patients were considered "cured" if the symptoms of PP had regressed and the hormone profile had normalized after surgery. Indications for surgery included hamartoma deemed surgically resectable (n-12), for the purpose of tissue diagnosis (n-3), partial response/failure of preoperative therapy (n-9), and unable to afford/to avoid long-term medical therapy (n-7). The extent of resection was total (TR) (n-39), near total/subtotal (NTR/STR) (n-20), partial (PR) (n-35), or unspecified (n-9). On follow-up (range: 3 months-16 years), 73.6% (56/76) of patients with pedunculated HH were cured, while 17.1% (13/76) had partial relief. Only 3/27 (11.1%) of patients with sessile HH were cured. All patients with a pedunculated hamartoma who underwent TR (n=36) improved, with 88.88% cured of the symptoms. Surgery had no effect in 17/23 (73.9%) patients with sessile HH who underwent PR. Psychological symptoms improved in 10/11 patients. There was no mortality. Permanent complications, in the form of 3rd nerve palsy, occurred in 3.7% (2/54) of the patients. To conclude, in the current era of availability of GnRH analogs, surgical resection in a subset of patients may be acceptable especially for small pedunculated hamartomas.

Optimized SEEG-guided radiofrequency thermocoagulation in the treatment of pediatric hypothalamic hamartomas

PURPOSE

This study investigated the role of one-stage stereo-array radiofrequency thermocoagulation based on stereotactic electroencephalography in the treatment of pediatric hypothalamic hamartomas.

METHODS

We analyzed the clinical data of 28 patients with hypothalamic hamartoma. A high-density focal stereo-array electrode implantation strategy was adopted. Stereotactic electroencephalography guided bipolar coagulations were performed between two contiguous contacts of the same electrode, or between two adjacent contacts of different electrodes. Patients with hypothalamic hamartoma were divided into two groups based on hamartoma size (maximum diameter < 15 mm vs maximum diameter ≥ 15 mm). Numbers of implanted electrodes and contacts used for thermocoagulation were documented. Seizure outcome was evaluated according to Engel's classification.

RESULTS

Surgical procedures were well tolerated and no repeated surgery was performed. The median number of electrodes implanted in the two groups was significantly different (p =  0.0009), as well as the median number of contacts where radiofrequency thermocoagulation was applied (p =  0.0006). Moreover, the number of implanted electrodes and contacts used for thermocoagulation were positively correlated with the hamartoma volume (Spearman's rho = 0.7074, p＜0.0001 and Spearman's rho = 0.7435, p＜0.0001, respectively). The overall seizure-free rate was 82.1 %, with 92.9 % of the patients having favorable outcomes for at least 12 months of follow-up. Seizure outcomes between two groups were not statistically significant (p =  0.3138).

CONCLUSION

One-stage high-density focal stereo-array stereotactic electroencephalography guided radiofrequency thermocoagulation using cross-bonded electrode contacts for ablation range expansion is a safe and effective surgical approach for children with hypothalamic hamartoma.

Pre- and postnatal MR imaging of an asymptomatic giant hypothalamic hamartoma

Hypothalamic hamartomas are rare tumors that are most often diagnosed in early childhood. These lesions are classified as giant hypothalamic hamartomas when they exceed 4 cm in any 1 dimension. The most common presenting symptoms associated with these lesions are precocious puberty, gelastic seizures, and (less commonly) syndromic conditions such as Pallister-Hall syndrome. We present a unique case of an asymptomatic giant hypothalamic hamartoma diagnosed prenatally by fetal magnetic resonance imaging and followed throughout infancy. This case demonstrates the utility of multimetric analysis using difference sequences, including diffuse-weighted imaging, to assess specific properties of intracranial lesions detected in utero and to aid in accurate diagnosis prior to birth.

Hypothalamic hamartoma with epilepsy: Review of endocrine comorbidity

The most common, and usually the only, endocrine disturbance in patients with hypothalamic hamartoma (HH) and epilepsy is central precocious puberty (CPP). The mechanism for CPP associated with HH may relate to ectopic generation and pulsatile release of gonadotropin-releasing hormone (GnRH) from the HH, but this remains an unproven hypothesis. Possible regulators of GnRH release that are intrinsic to HH tissue include the following: (1) glial factors (such as transforming growth factor α[TGFα) and (2) γ-aminobutyric acid (GABA)-mediated excitation. Both are known to be present in surgically-resected HH tissue, but are present in patients with and without a history of CPP, suggesting the possibility that symptoms related to HH are directly associated with the region of anatomic attachment of the HH to the hypothalamus, which determines functional network connections, rather than to differences in HH tissue expression or pathophysiology. CPP associated with HH presents with isosexual development prior to the age of 8 years in girls and 9 years in boys. It is not uncommon for CPP with HH to present in children at an earlier age in comparison to other causes of CPP, including in infancy. Surgical resection of the HH can be effective for treating CPP, but is reserved for patients with intractable epilepsy, since GnRH agonists are widely available and effective treatment. Other endocrine disturbances with HH are rare, but can include growth hormone deficiency, hypothyroidism, and adrenal insufficiency. Diabetes insipidus is commonly encountered postoperatively, but is not observed with HH prior to surgical intervention.

How would we deal with hypothalamic hamartomas?

Hypothalamic hamartoma (HH) is usually associated with refractory epilepsy, cognitive impairment, and behavioral disturbance. There is now increasing evidence that HH can be treated effectively with a variety of neurosurgical approaches. Treatment options for intractable gelastic seizure in HH patients include direct open surgery with craniotomy, endoscopic surgery, radiosurgery with gamma knife and stereotactic radiofrequency thermocoagulation. Selection of treatment modalities depends on type and size of the HH and the surgeon’s preference. Two surgical techniques, resection and disconnection, had been described with favorable outcomes. Pretreatment evaluation, patient selection, surgical techniques, complications, and possible selection of treatment are discussed.