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Sandipan Pati, Adib A. Abla, Harold L. Rekate and Yu-Tze Ng

Object

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

Methods

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

Results

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

Conclusions

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

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Yu-tze Ng, John F. Kerrigan and Harold L. Rekate

Object

The purpose of this study was to report the cases of five patients with status epilepticus who were treated successfully with neurosurgery.

Methods

Five children presented with refractory status epilepticus, including complex partial status epilepticus, epilepsia partialis continua and “status gelasticus.” Multiple medical therapies had failed to control the seizures, and focal resection was performed. Seizures were fully controlled in four patients, and in one patient seizure frequency was reduced by more than 90%.

Conclusions

Refractory status epilepticus is associated with a high mortality rate and by definition does not respond well to medical treatment, even optimal medical treatment. Neurosurgical treatment should be considered as another therapeutic option once medical management has failed, and neurosurgery should not necessarily be a last resort.

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Yu-tze Ng, John F. Kerrigan, Erin C. Prenger, William L. White and Harold L. Rekate

P The authors report the case of a 12-year-old girl with Pallister—Hall syndrome, long-standing refractory, symptomatic epilepsy, mental retardation, and panhypopituitarism in whom two rare, deep midline lesions were detected. She underwent successful transsphenoidal resection of the Rathke cleft cyst and transcallosal resection of the hypothalamic hamartoma within a 4-day period without complications. Neuropathological studies confirmed the neuroimaging diagnoses for the two lesions. The patient has been seizure free for 6 months postoperatively.

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Iman Feiz-Erfan, Eric M. Horn, Harold L. Rekate, Robert F. Spetzler, Yu-Tze Ng, Jeffrey V. Rosenfeld and John F. Kerrigan III

Object

The authors provide evidence that direct resection of hypothalamic hamartomas (HHs) can improve associated gelastic and nongelastic seizures.

Methods

Ten children younger than 17 years of age underwent resection of HHs (nine sessile and one pedunculated) that were causing refractory epilepsy. Lesions were approached from above transventricularly through a transcallosal anterior interforniceal approach in six cases, endoscopically through the foramen of Monro in one, and from below with a frontotemporal craniotomy including an orbitozygomatic osteotomy in three. Medical charts were reviewed retrospectively, and follow-up data were obtained through office records and phone calls.

Follow-up periods ranged between 12 and 84 months (mean 16.8 months). All patients in whom the approach was from above had sessile HHs. Five were free from seizures at follow up and two had a reduction in seizures of at least 95%. The transventricular route allowed excellent exposure and visualization of the local structures during resection. Among the three patients in whom the approach was from below, one became free of seizure after two procedures and one had a 75% reduction in epilepsy; the latter two had sessile HHs. The exposure was inadequate, and critical tissue borders were not readily apparent. Although the HH was adequately exposed and resected, the epilepsy persisted in the third patient, who had a pedunculated lesion. The overall rate of major permanent hypothalamic complications appeared to be slightly lower for the orbitozygomatic osteotomy group.

Conclusions

Sessile lesions are best approached from above. Approaches from below adequately expose pedunculated hamartomas. The likelihood of curing seizures seems to be higher when lesions are approached from above rather than from below.

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Sandipan Pati, Reena G Rastogi, Adib A. Abla, Harold L. Rekate and Yu-Tze Ng

Object

Gelastic seizures are epileptic events characterized by bouts of laughter. They are rare and mostly associated with hypothalamic hamartomas (HHs). Status gelasticus, a rare form of status epilepticus, is defined as a prolonged cluster of gelastic seizures (> 20–30 minutes) without necessarily involving loss of awareness between seizures. Emergency resection of the hamartoma is highly effective in these situations and should be considered as early as possible. The authors retrospectively reviewed their surgical cases to document the success, complications, and long-term follow-up after emergency resection of HHs for status gelasticus.

Methods

The authors report on a retrospective case series from a single tertiary care center. Three patients who presented with status gelasticus underwent emergency resection of HHs. Demographic details, seizure history, medical treatment, and postoperative follow-up data were evaluated. Long-term follow-up (minimum 2 years) data were obtained either from the last clinic visit notes or via telephone and e-mail contacts. The institutional review board at St. Joseph's Hospital approved this study.

Results

In the last 7 years, of 157 patients who underwent HH resection, the resection was performed on an emergency basis for status gelasticus in 3 cases. At emergency surgery, these 3 patients ranged in age from 9 months to 3.5 years. All of the patients were boys. Delalande and Fohlen Type II, III, and IV lesions were present in the 3 patients. Surgical approaches for resection of HH included an orbitozygomatic, transcallosal anterior interforniceal approach and endoscopic resection. Status gelasticus was terminated following emergency surgery in all cases, and 1 patient was seizure free. Postsurgical complications included, in 1 case, a small right thalamic infarct with mild transient left hemiparesis, which completely resolved within 2 days. Within 2 years of their original surgery, 2 patients underwent further elective surgeries (endoscopic resection and radiosurgery for persistent symptomatic seizures). Follow-up since their most recent surgery ranged from 8 months to 2 years. Two patients were seizure free and 1 patient had greater than 50% reduction in seizures.

Conclusions

Status gelasticus associated with HHs can be successfully terminated by emergency resection of the HH. Long-term follow-up in the present series suggests good seizure freedom results or at least greater than 50% reduction in seizures, although repeat operations were necessary.

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Adib A. Abla, Andrew G. Shetter, Steve W. Chang, Scott D. Wait, David G. Brachman, Yu-Tze Ng, Harold L. Rekate and John F. Kerrigan

Object

The authors present outcomes obtained in patients who underwent Gamma Knife surgery (GKS) at 1 institution as part of a multimodal treatment of refractory epilepsy caused by hypothalamic hamartomas (HHs).

Methods

Between 2003 and 2010, 19 patients with HH underwent GKS. Eight patients had follow-up for less than 1 year, and 1 patient was lost to follow-up. The 10 remaining patients (mean age 15.1 years, range 5.7–29.3 years) had a mean follow-up of 43 months (range 18–81 months) and are the focus of this report. Five patients had undergone a total of 6 prior surgeries: 1 transcallosal resection of the HH, 2 endoscopic transventricular resections of the HH, 2 temporal lobectomies, and 1 arachnoid cyst evacuation. In an institutional review board–approved study, postoperative complications and long-term outcome measures were monitored prospectively with the use of a proprietary database. Seven patients harbored Delalande Type II lesions; the remainder harbored Type III or IV lesions. Seizure frequency ranged from 1–2 monthly to as many as 100 gelastic seizures daily. The mean lesion volume was 695 mm3 (range 169–3000 mm3, median 265 mm3). The mean/median dose directed to the 50% isodose line was 18 Gy (range 16–20 Gy). The mean maximum point dose to the optic chiasm was 7.5 Gy (range 5–10 Gy). Three patients underwent additional resection 14.5, 21, and 32 months after GKS.

Results

Of the 10 patients included in this study, 6 are seizure free (2 after they underwent additional surgery), 1 has a 50%–90% reduction in seizure frequency, 2 have a 50% reduction in seizure frequency, and 1 has observed no change in seizure frequency. Overall quality of life, based on data obtained from follow-up telephone conversations and/or surveys, improved in 9 patients and was due to improvements in seizure control (9 patients), short-term memory loss (3 patients), and behavioral symptoms (5 patients); in 1 patient, quality of life remains minimally affected. Incidences of morbidity were all temporary and included poikilothermia (1 patient), increased depression (1 patient), weight gain/increased appetite (2 patients), and anxiety (1 patient) after GKS.

Conclusions

Of the approximately 150 patients at Barrow Neurological Institute who have undergone treatment for HH, the authors have reserved GKS for treatment of small HHs located distal from radiosensitive structures in patients with high cognitive function and a stable clinical picture, which allows time for the effects of radiosurgery to occur without further deterioration. The lack of significant morbidity and the clinical outcomes achieved in this study demonstrated a low risk of GKS for HH with results comparable to those of previous series.

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Adib A. Abla, Scott D. Wait, Jonathan A. Forbes, Sandipan Pati, Roger E. Johnsonbaugh, John F. Kerrigan and Yu-Tze Ng

Object

In this paper, the authors' goal was to describe the occurrence of alternating hypernatremia and hyponatremia in pediatric patients who underwent resection of hypothalamic hamartomas (HHs) for epilepsy. Hypernatremia in patients after pituitary or hypothalamic surgery can be caused by diabetes insipidus (DI), whereas hyponatremia can occur due to a syndrome of inappropriate antidiuretic hormone, cerebral salt wasting, or excessive administration of desmopressin (DDAVP). The triphasic response after surgery in the pituitary region can also explain variations in sodium parameters in such cases.

Methods

One hundred fifty-three patients with HH who underwent surgery were enrolled in a prospective study to monitor outcomes. Of these, 4 patients (2.6%) were noted to experience dramatic alterations in serum sodium values. The medical records of these patients were identified and evaluated.

Results

Patients' ages at surgery ranged from 1.2 to 6.0 years. All patients were girls. Two patients had Delalande Type IV lesions (of 16 total Type IV lesions surgically treated) and 2 had Type III lesions (of 39 total Type III lesions). All patients had a history of gelastic seizures refractory to medication. Seizure frequency ranged from 3 to 300 per day. After surgery, all patients experienced hypernatremia and hyponatremia. The largest fluctuation in serum sodium concentration during hospitalization in a single patient was 53 mEq/L (range 123–176 mEq/L). The mean absolute difference in maximum and minimum sodium values was 38.2 mEq/L.

All patients exhibited an initial period of immediate DI (independent of treatment) after surgery followed by a period of hyponatremia (independent of treatment), with a minimum value occurring between postoperative Days 5 and 8. All patients then returned to a hypernatremic state of DI, and 3 patients still require DDAVP for DI management. A second occurrence of hyponatremia lasting several days without DDAVP administration occurred in 2 patients during their hospitalization between periods of hypernatremia. One patient stabilized in the normal range of sodium values prior to discharge from rehabilitation without the need for further intervention. At last follow-up, 3 patients are seizure-free.

Conclusions

Severe instability of sodium homeostasis with hypernatremia and hyponatremia is seen in up to 2.6% of children undergoing open resection of HH. This risk appears to be related to HH type, with a higher risk for Types III (2 [5.1%] of 39) and IV (2 [12.5%] of 16) lesions. Here, the authors describe alternating episodes of hypernatremia and hyponatremia in the postoperative period following HH surgery. Management of this entity requires careful serial assessment of volume status and urine concentration and will often require alternating salt replacement therapy with DDAVP administration.