Neurenteric cyst of the area postrema causing intractable nausea and vomiting.

Neurenteric cysts are rare, benign congenital lesions of the central nervous system. We present a case of a 59-year-old woman with intractable daily nausea and vomiting with a fourth ventricular cyst adjacent to the area postrema. This was surgically resected leading to complete symptom resolution.

Increased cardiac sympathetic nerve activity in ovine heart failure is reduced by lesion of the area postrema, but not lamina terminalis.

Increased cardiac sympathetic nerve activity (CSNA) is a key feature of heart failure (HF) and is associated with poor outcome. There is evidence that central angiotensinergic mechanisms contribute to the increased CSNA in HF, but the central sites involved are unknown. In an ovine, rapid pacing model of HF, we investigated the contribution of the lamina terminalis and area postrema to the increased CSNA and also the responses to fourth ventricular infusion of the angiotensin type 1 receptor antagonist losartan. Ablation of the area postrema or sham lesion (n = 6/group), placement of lamina terminalis lesion electrodes (n = 5), and insertion of a cannula into the fourth ventricle (n = 6) were performed when ejection fraction was ~ 50%. When ejection fraction was < 40%, recording electrodes were implanted, and after 3 days, resting CSNA and baroreflex control of CSNA were measured before and following lesion of the lamina terminalis, in groups with lesion or sham lesion of the area postrema and before and following infusion of losartan (1.0 mg/h for 5 h) into the fourth ventricle. In conscious sheep with HF, lesion of the lamina terminalis did not significantly change CSNA (91 ± 2 vs. 86 ± 3 bursts/100 heart beats), whereas CSNA was reduced in the group with lesion of the area postrema (89 ± 3 to 45 ± 10 bursts/100 heart beats, P < 0.01) and following fourth ventricular infusion of losartan (89 ± 3 to 48 ± 8 bursts/100 heartbeats, P < 0.01). These findings indicate that the area postrema and brainstem angiotensinergic mechanisms may play an important role in determining the increased CSNA in HF.

Brain tumors and the area postrema.

Brain tumors can rarely present with symptoms mistaken for anorexia nervosa. We report a patient with a long-standing history of anorexia who developed headaches and was found on brain MRI to have a brain tumor in the area of the fourth ventricle. On admission, the patient presented with a 4 month history of headaches and a 10 year history of "anorexia nervosa". Interestingly, the patient did not endorse the classic sense of an altered self-body image. Her body weight on admission was 37 kg. The patient underwent surgical resection of the tumor. On postoperative day (POD) 1, the patient subjectively reported an increased appetite. On POD 2, we documented that she finished her entire food tray for the first time during her hospital stay. Her peri-operative course was without any complications. She presented for a follow-up clinic visit 2 weeks postoperatively and was noted to have a new body weight of 47 kg (10 kg gain). To our knowledge, this is the first reported occurrence of a sporadic, and third overall occurrence, of a hemangioblastoma that presented with an anorexia nervosa-like syndrome that was ultimately cured with surgical resection. In patients presenting with a history of psychiatric illness, it is important to consider the possibility of underlying, organic pathologies in the central nervous system affecting the relevant neuro-anatomical domains.

Chronic emesis due to compression of the area postrema by the posterior inferior cerebellar artery: resolution following microvascular decompression.

Chronic emesis may result from a variety of causes. To the authors' knowledge, compression of the area postrema by regional vessels resulting in chronic emesis has not been reported. The authors report on a child who presented with chronic medically intractable emesis and significant weight loss requiring jejunostomy feeding. Surgical exploration of the posterior cranial fossa found unilateral compression of the area postrema by the posterior inferior cerebellar artery. Microvascular decompression resulted in postoperative and long-term resolution of the patient's emesis. Although apparently very rare, irritation of the area postrema from the posterior inferior cerebellar artery with resultant medically intractable chronic emesis may occur. Therefore, the clinician should be aware of this potential etiology when dealing with such patients.

Clinical and surgical features of lower brain stem hemangioblastomas in von Hippel-Lindau disease.

BACKGROUND: In the context of von Hippel-Lindau disease (VHL), the medulla oblongata is a relatively frequent site of growth of hemangioblastomas, posing related clinical and surgical difficulties. Their management requires a close correlation between clinical evolution and morphological surveillance. In order to describe their clinical and surgical features, we reviewed our experience in the treatment of these lesions. METHODS: Between 2001 and 2009, 14 patients (9 female and 5 male, mean age 34 years) underwent removal of 15 lower brain stem hemangioblastomas. Based on the review of the clinical records and outpatient long-term follow-up visits, their clinical course was analyzed. Functional evaluation was measured with the Karnofsky Performance Scale (KPS) on admission, at discharge and at the last follow-up. The mean follow-up period was 30.8 months (range 4-99). RESULTS: All the operated hemangioblastomas were located in the dorsal medulla oblongata, in the context of multiple lesions, cerebellar and/or spinal. In ten patients hemangioblastomas were located in a median position at the obex area; in four cases a lateral location was observed. Cystic component was absent in two cases. Clinical onset preceded surgery by a mean of 8.5 months. Preoperatively three patients showed a KPS lower than 80, ten patients between 80 and 90, and one patient scored 100 (asymptomatic). There was no surgical mortality. Nine out of 14 patients showed a temporary surgical morbidity. One patient required a tracheostomy. At follow-up ten patients scored a KPS better than before the operation, while the other four patients remained stable. Permanent morbidity was observed in three patients. CONCLUSIONS: Lower brain stem hemangioblastomas in the context of VHL show an often gradual onset of signs and symptoms except for patients who develop an obstructive hydrocephalus. Although transient surgical complications are possible, surgery provides favorable long-term results.

Area postrema-lesions increase operant responding to sucrose in rats.

Rats with lesions of the area postrema (APX) are known to exhibit an enhanced intake of highly palatable foods such as sweetened condensed milk and cookies. These observations suggest the possibility that APX rats find these foods more rewarding and will work harder to obtain these foods. Sham and APX rats were tested on fixed ratio (FR) and progressive ratio (PR) schedules. APX rats consistently pressed more times to receive sucrose solution and attained both FR 3 and FR 5 criteria significantly faster than sham-lesioned control rats. Furthermore, rats with APX had significantly higher break points than sham-lesioned control rats on a progressive ratio schedule. These results support the hypothesis that rats with lesions of the area postrema will consistently work harder to obtain a highly palatable food reward.

Cardiovascular function and circadian patterns in rats after area postrema lesions or prolonged food restriction.

The role of the area postrema (AP) in baseline cardiovascular function was evaluated by radio telemetry in rats with lesions of AP (APX), along with the effect of APX on circadian patterns of cardiovascular function and ingestive behavior. Despite lesion-induced hypophagia and body weight loss, APX did not affect circadian patterns of mean arterial pressure (MAP), heart rate (HR), or ingestion but did cause a substantial decrease (-60 bpm) in resting HR. The bradycardia was not attributable to weight loss, as resting HR in weight-matched controls, though decreased from baseline, was significantly greater than that in rats with APX. In weight-matched controls, HR increased slightly when weight returned to baseline; however, the bradycardia persisted in rats with APX. These results suggest that AP contributes to resting HR, independent of weight loss or changes in circadian patterns of HR or MAP.