Surgical therapy of lesions within the hypothalamic region

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.

Endoscopic surgery for hypothalamic hamartomas causing medically refractory gelastic epilepsy

INTRODUCTION

There is increasing evidence that removal or disconnection of hypothalamic hamartomas can lead to seizure control and improvement in behavior. The purpose of this study is to report our experiences with endoscopic removal of these hamartomas.

METHODS

This is a prospective review of the early outcome of 44 patients undergoing endoscopic resection utilizing frameless stereotaxis and a micromanipulator.

RESULTS

All patients had normal-sized ventricles. Complete removal was possible in 14 patients, 13 of whom were seizure free at follow-up. Four patients suffered complications that have persisted for more than 3 months: One had significant hemiparesis and three had persistent difficulties with short-term memory. Postoperatively, no patient suffered a permanent hormonal deficiency. In one patient who had undergone a previous attempt at transcallosal resection, the procedure was abandoned because of the lack of internal anatomic landmarks. In a second patient, insufficient mass could be removed due to the size of the lesion and the distorted anatomy. Consequently, 1 week later, the patient underwent a transcallosal approach.

CONCLUSION

In appropriately selected patients, sessile hypothalamic hamartomas can be removed completely or they can be completely disconnected from the hypothalamus with an acceptable risk. At least a year after surgery is needed to evaluate the efficacy of the procedure in terms of control of seizures and improvements in behavior and emotional ability.

Altered sympathetic thermoregulation in patients with hypothalamic dysfunction following resection of suprasellar tumors

In patients with suprasellar tumors, both the tumor and its surgical resection may produce hypothalamic dysfunction including thermoregulatory disturbances. We quantitated skin sympathetic nerve activity using microneurography in eight patients with hypothalamic dysfunction following resection. Skin sympathetic nerve activity, skin blood flow (by laser Doppler flowmetry), sweating, blood pressure, and pulse rate were monitored during changes of core (tympanic) temperature in the patients and seven healthy controls. Core temperature was decreased by 0.3 degrees C and increased by 0.5 degrees C relative to baseline using a cooling/heating blanket. The increase in sympathetic nerve activity in response to cooling did not differ between controls and patients (41.0+/-13.1 vs. 38.1+/-7.7 bursts [min degrees C](-1)), but an increase upon heating in controls (45.1+/-5.4 bursts [min degrees C](-1)) was absent in the patients (-26.0+/-17.5 bursts [(min degrees C](-1)). Skin blood flow during heating increased significantly in controls but not in patients (35.6+/-14.6 vs. 15.8+/-5.8 ml [min 100 g tissue degrees C](-1)). The patients thus showed impaired heat loss during body temperature elevation. Microneurography proved to be a sensitive measure of hypothalamic autonomic function.

Resection of suprasellar tumors by using a modified transsphenoidal approach. Report of four cases

Generally accepted contraindications to using a transsphenoidal approach for resection of tumors that arise in or extend into the suprasellar region include a normal-sized sella turcica, normal pituitary function, and adherence of tumor to vital intracranial structures. Thus, the transsphenoidal approach has traditionally been restricted to the removal of tumors involving the pituitary fossa and, occasionally, to suprasellar extensions of such tumors if the sella is enlarged. However, conventional transcranial approaches to the suprasellar region require significant brain retraction and offer limited visualization of contralateral tumor extension and the interface between the tumor and adjacent structures, such as the hypothalamus, third ventricle, optic apparatus, and major arteries. In this paper the authors describe successful removal of suprasellar tumors by using a modified transsphenoidal approach that circumvents some of the traditional contraindications to transsphenoidal surgery, while avoiding some of the disadvantages of transcranial surgery. Four patients harbored tumors (two craniopharyngiomas and two hemangioblastomas) that arose in the suprasellar region and were located either entirely (three patients) or primarily (one patient) within the suprasellar space. All patients had a normal-sized sella turcica. Preoperatively, three of the four patients had significant endocrinological deficits signifying involvement of the hypothalamus, pituitary stalk, or pituitary gland. Two patients exhibited preoperative visual field defects. For tumor excision, a recently described modification of the traditional transsphenoidal approach was used. Using this modification, one removes the posterior portion of the planum sphenoidale, allowing access to the suprasellar region. Total resection of tumor was achieved (including absence of residual tumor on follow-up imaging) in three of the four patients. In the remaining patient, total removal was not possible because of adherence of tumor to the hypothalamus and midbrain. One postoperative cerebrospinal fluid leak occurred. Postoperative endocrinological function was worse than preoperative function in one patient. No other new postoperative endocrinological or neurological deficits were encountered. This study demonstrates the feasibility of using a modified transsphenoidal approach for resection of certain suprasellar, nonpituitary tumors.

Oncologic causes of precocious puberty

Tumors are rare, but well-documented causes of precocious puberty in both sexes. The therapeutic and prognostic implications of a diagnosis of cancer require that the presence of a neoplastic process be ruled out in any case of precocious puberty. Granulosa-cell tumor of the ovary and Leydig-cell tumor of the testis are the most frequent gonadal tumors inducing precocious pseudopuberty in the two sexes. Adrenal tumors sustain a variety of endocrine syndromes, the most frequent one being virilization with or without hypercortisolism. Pure feminizing adrenal neoplasms have been described. For reasons not yet well understood, hypothalamochiasmatic glioma (beta-HCG) secreting tumors have almost never been described in association with female precocious puberty. Among these neoplasia, pineal germ-cell tumor inducing sexual maturation must be included. Hypothalamochiasmatic glioma and craniopharyngioma are the two cerebral tumors capable of inducing true precocious puberty. Even if equally distributed between both sexes, these tumors interfere with sexual maturation less frequently in girls than in boys. Hypothalamic hamartoma is considered a benign tumor, since it does represent a space-occupying mass. It more correctly could be called a malformation if its histologic characteristics are recalled. This cerebral lesion is now frequently described in children with true precocious puberty, probably because of improved diagnostic imaging methods.

Autoantibodies to pituitary corticotropin-producing cells: possible marker for unfavourable outcome after pituitary microsurgery for Cushing's disease

Circulating autoantibodies to human fetal pituitary cells were detected in 13 out of 51 patients who underwent transsphenoidal microsurgery for Cushing's disease. The absence of Fc receptors on human fetal pituitary corticotropin-producing cells allowed the detection of antibodies to these cells. In all the 13 patients, the antibodies were present before surgery, and 10 of them showed clinical and/or biochemical signs of incomplete cure of Cushing's disease after surgery. Only 3 out of 27 patients with a favourable outcome were antibody-positive. In all the antibody-positive patients, the antibodies were directed to corticotropin-producing cells and in 8 patients also to luteinising hormone or human growth hormone producing cells. A non-antigen-specific adherence of antibodies to Fc-receptors on corticotropin-cells was excluded by unchanged binding after preincubation of sections with purified rabbit Fc or Fc aggregates. The presence of pituitary corticotropin-cell antibodies in patients with Cushing's disease is associated with an unsuccessful outcome after transsphenoidal selective adenectomy.

Repeatedly reversible alteration of acoustic-evoked brainstem responses with a cystic craniopharyngioma

The case of a cystic craniopharyngioma in a young patient, in which the tumor extended in the parasellar and retrosellar region down to the left cerebellopontine angle, is described. The postoperative reversibility of alterations in the acoustic-evoked brainstem responses after repeated surgical intervention and refilling of the cyst is described. The correlations between clinical and CT findings and the repeated alterations in the evoked responses are presented. The evoked responses were instrumental in following the postoperative course and timing CT controls. It is stressed that alterations in evoked responses were used as a reliable indication to evacuate cyst fluid via a Rickham-reservoir, although hearing was still intact, thus keeping the number of repeated CT scans lower.