Transcallosal resection of hypothalamic hamartoma for gelastic epilepsy

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.

The American Society for Stereotactic and Functional Neurosurgery Position Statement on Laser Interstitial Thermal Therapy for the Treatment of Drug-Resistant Epilepsy

Magnetic resonance image-guided laser interstitial thermal therapy (MRgLITT) is a novel tool in the neurosurgical armamentarium for the management of drug-resistant epilepsy. Given the recent introduction of this technology, the American Society for Stereotactic and Functional Neurosurgery (ASSFN), which acts as the joint section representing the field of stereotactic and functional neurosurgery on behalf of the Congress of Neurological Surgeons and the American Association of Neurological Surgeons, provides here the expert consensus opinion on evidence-based best practices for the use and implementation of this treatment modality. Indications for treatment are outlined, consisting of failure to respond to, or intolerance of, at least 2 appropriately chosen medications at appropriate doses for disabling, localization-related epilepsy in the setting of well-defined epileptogenic foci, or critical pathways of seizure propagation accessible by MRgLITT. Applications of MRgLITT in mesial temporal lobe epilepsy and hypothalamic hamartoma, along with its contraindications in the treatment of epilepsy, are discussed based on current evidence. To put this position statement in perspective, we detail the evidence and authority on which this ASSFN position statement is based.

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.

Emerging indications for stereotactic laser interstitial thermal therapy in pediatric neurosurgery

Surgical treatment of deep or difficult to access lesions represents a unique and significant challenge for pediatric neurosurgeons. The introduction of stereotactic magnetic resonance-guided laser interstitial thermal therapy (LITT) over the last decade has had a dramatic impact on the landscape of pediatric neurosurgery. LITT provides a safe and effective option for children with epilepsy from hypothalamic hamartoma that represents a ground-breaking new therapy for a condition which was historically very difficult to treat with previous neurosurgical techniques. LITT has also been used as an alternative surgical technique for mesial temporal sclerosis, focal cortical dysplasia, MR-negative epilepsy, cavernoma-related epilepsy, insular epilepsy, and corpus callosotomy among other epilepsy etiologies. In some cases, LITT has been associated with improved cognitive outcomes compared to standard techniques, as in mesial temporal lobe epilepsy. Initial experiences with LITT for neuro-oncologic processes are also promising. LITT is often attractive to patients and providers as a minimally invasive approach, but the differences in safety and clinical outcome between LITT and traditional approaches are still being studied. In this review, we examine the emerging indications and clinical evidence for LITT in pediatric neurosurgery.

Magnetic Resonance Imaging-Guided Laser Interstitial Thermal Therapy for Epilepsy: Systematic Review of Technique, Indications, and Outcomes

BACKGROUND

For patients with focal drug-resistant epilepsy (DRE), surgical resection of the epileptogenic zone (EZ) may offer seizure freedom and benefits for quality of life. Yet, concerns remain regarding invasiveness, morbidity, and neurocognitive side effects. Magnetic resonance-guided laser interstitial thermal therapy (MRgLITT) has emerged as a less invasive option for stereotactic ablation rather than resection of the EZ.

OBJECTIVE

To provide an introduction to MRgLITT for epilepsy, including historical development, surgical technique, and role in therapy.

METHODS

The development of MRgLITT is briefly recounted. A systematic review identified reported techniques and indication-specific outcomes of MRgLITT for DRE in human studies regardless of sample size or follow-up duration. Potential advantages and disadvantages compared to available alternatives for each indication are assessed in an unstructured review.

RESULTS

Techniques and outcomes are reported for mesial temporal lobe epilepsy, hypothalamic hamartoma, focal cortical dysplasia, nonlesional epilepsy, tuberous sclerosis, periventricular nodular heterotopia, cerebral cavernous malformations, poststroke epilepsy, temporal encephalocele, and corpus callosotomy.

CONCLUSION

MRgLITT offers access to foci virtually anywhere in the brain with minimal disruption of the overlying cortex and white matter, promising fewer neurological side effects and less surgical morbidity and pain. Compared to other ablative techniques, MRgLITT offers immediate, discrete lesions with real-time monitoring of temperature beyond the fiber tip for damage estimates and off-target injury prevention. Applications of MRgLITT for epilepsy are growing rapidly and, although more evidence of safety and efficacy is needed, there are potential advantages for some patients.

Open resection of hypothalamic hamartomas for intractable epilepsy revisited, using intraoperative MRI

INTRODUCTION

Hypothalamic hamartomas (HHs) are rare non-neoplastic lesions which cause drug-resistant epilepsy with associated behavioural, psychiatric and endocrine issues. With the development of new minimally invasive techniques for the treatment of HH, there is a need to reappraise the effectiveness and safety of each approach. We review the outcomes of HH patients treated surgically, utilizing intraoperative magnetic resonance imaging (IOMRI), by a team of Alder Hey NHS Foundation Trust tumour and epilepsy neurosurgeons since 2011.

METHODS

Patient records of all HH cases operated on since 2011 were reviewed to confirm history of presentation and clinical outcomes.

RESULTS

Ten patients have undergone surgery for HH under the dual care of Alder Hey tumour and epilepsy neurosurgeons during this period. Eight cases had a midline transcallosal, interforniceal approach with the remaining 2 having a transcallosal, transforaminal approach. All patients had an IOMRI scan, with 40% needing further tumour resection post-IOMRI. Forty percent had a total resection, 3 patients had near-total resection and 3 patients had subtotal resection (~ 30% tumour residual on post-operative MRI). No new neurological complications developed post-operatively. Hypothalamic axis derangements were seen in 3 cases, including 1 diabetes insipidus with hypocortisolaemia, 1 hypodipsia and 1 transient hyperphagia. Eighty percent are seizure free; the remaining two patients have had significant improvements in seizure frequency.

CONCLUSIONS

IOMR was used to tailor the ideal tumour resection volume safely based on anatomy of the lesion, which combined with the open transcallosal, interforniceal route performed by surgeons experienced in the approach resulted in excellent, safe and effective seizure control.

Classification of hypothalamic hamartoma and prognostic factors for surgical outcome

OBJECTIVES

The main aims of this study were to classify patients with hypothalamic hamartoma (HH) based on neuroimaging features and describe the clinical manifestations of HH.

MATERIALS AND METHODS

A retrospective review of 214 consecutive patients with HH treated in Beijing Tiantan Hospital was performed.

RESULTS

HH were diagnosed and divided into Types I-IV based on MRI. Types I and II were defined as the HH attached to the floor of the third ventricle with narrow (Type I) or broad (Type II) interfaces. Type III ('straddling') was defined by the HH extending into the third ventricle and interpeduncular cistern. Type IV was defined as the HH located totally within the third ventricle. The percent distribution of patients was 35.9% Type I, 12.1% Type II, 40.7% Type III, and 11.2% Type IV. The percentage of patients with precocious puberty was highest in Type I (81.8%). The percentage of patients with gelastic seizures was highest in Type IV (91.7%). After surgery, 20% (1/5) of patients with Type II HH, 48.8% (20/42) with Type III, and 91.7% (11/12) with Type IV were free of epileptic seizures. Significant prognostic factors for surgical outcome were HH size, surgical approach, and resection level.

CONCLUSIONS

The clinical manifestations of HH are correlated with the topology of the HH in relation to the hypothalamus. Our results suggest that patients with Type IV HH have the best outcome from surgery and neurosurgeons should be cautious about performing surgery on patients with Type II and Type III HH.

Predictors of inpatient complications and outcomes following surgical resection of hypothalamic hamartomas

Background:

Our aim was to identify the preoperative factors associated with a greater risk of poor inpatient outcomes in those undergoing resection of hypothalamic hamartomas.

Methods:

We performed a multi-institutional retrospective cohort analysis via the Nationwide Inpatient Sample (1998 – 2007). Patients of any age who underwent resection of hypothalamic hamartomas were identified by ICD-9 coding. The primary outcomes included inpatient complications, length of stay (LOS), and total charges. Multivariate regression models were constructed to analyze the outcomes.

Results:

Two hundred and eighty-two patients were identified with a mean age of 27.7 years, with most being male (53.2%), Caucasian (78.9%), privately insured (69.3%), and treated electively (74.7%) at academic centers (91.7%). A majority (82.2%) had Elixhauser comorbidity scores of < 1, indicating few comorbidities. No inpatient deaths were reported. Mean LOS was 7.39 days and the mean total hospital charges were $53,935. Overall, 19.5% developed an inpatient complication, primarily stroke (16.7%). Female gender, ethnic / racial minorities, higher comorbidity scores, private insurance, and non-academic hospitals were associated with greater LOS and total charges. Private insurance (Odds Ratio, OR: 1.59, P = 0.045) and academic hospitals (OR: 1.43, P = 0.008) were associated with significantly higher odds of any complication. Minority race / ethnicity was associated with a minimal increase in the odds of postoperative stroke (OR: 1.02, P < 0.001) relative to Caucasians.

Conclusions

Through an analysis of a 10-year multi-institutional database, we have described the surgical outcomes of patients undergoing resection of hypothalamic hamartomas. Results demonstrate significant inpatient morbidity, particularly postoperative stroke. Patient- and institution-level factors should be considered in determining the perioperative risk for such patients.

Minimally invasive magnetic resonance imaging-guided stereotactic radiofrequency thermocoagulation for epileptogenic hypothalamic hamartomas

OBJECTIVE

To validate the safety and efficacy of magnetic resonance imaging (MRI)-guided stereotactic radiofrequency thermocoagulation (SRT) for epileptogenic hypothalamic hamartoma (HH), we evaluated surgical outcomes and revised the MRI classification.

METHODS

We retrospectively reviewed 25 consecutive patients with HH (age range, 2-36 years; mean age, 14.8 years) with gelastic seizures. Other seizure types were exhibited in 22 patients (88.0%), precocious puberty in 8 (32.0%), behavioral disorder in 10 (40.0%), and mental retardation in 14 (56.0%). We classified HH into 3 subtypes according to coronal MRI: intrahypothalamic, parahypothalamic, and mixed hypothalamic type. Maximum diameter ranged from 8 to 30 mm (mean, 15.3 mm). All patients underwent SRT (74 degrees C, 60 seconds) for HH.

RESULTS

HH subtype and size were correlated with precocious puberty, mental retardation, and behavioral disorder. Thirty-one SRT procedures were performed, requiring 1 to 8 tracks (mean, 3.8 tracks) and involving 1 to 18 lesions (mean, 7.2 lesions). There were no adaptive limitations, regardless of size or subtype. Mixed-type HHs needed more tracks and more lesions. No permanent complications persisted after SRT, and gelastic seizures disappeared in all but 2 patients. Complete seizure freedom was achieved in 19 patients (76.0%). These patients had not only disappearance of all seizure types and behavioral disorder but also intellectual improvement.

CONCLUSION

The present SRT procedure has favorable efficacy and invasiveness and has no adaptive limitations. SRT should therefore be considered before adulthood. The new HH classification is useful to understand clinical symptoms and to determine surgical strategies.

Surgical management of hypothalamic hamartomas in patients with gelastic epilepsy

Gelastic epilepsy (GE) associated with hypothalamic hamartomas (HHs) is now a well-characterized clinical syndrome consisting of gelastic seizures starting in infancy, medically refractory seizures with or without the development of multiple seizure types, and behavioral and cognitive decline. It has been postulated that the development of the HH-GE syndrome is a result of a progressive epileptic encephalopathy or secondary epileptogenesis, which is potentially reversible with treatment of the HH. A variety of surgical options for the treatment of HHs exist, including open and endoscopic procedures, radiosurgery, interstitial radiotherapy, and stereotactic radiofrequency thermocoagulation. Surgical treatment can result in seizure freedom in up to 50% of patients and can be accompanied by significant improvements in behavior, cognition, and quality of life. Partial treatment of HHs may be sufficient to reduce seizure frequency and improve behavior and quality of life with less risk. A component of reversible cognitive dysfunction may be present in some patients with an HH-GE syndrome.