Anatomy,physiology, and pathophysiology of the pedunculopontine nucleus

The pedunculopontine nucleus is composed of cholinergic and non‐cholinergic neurones and is located in the caudal pontomesencephalic tegmentum. Evidence suggests that the nucleus plays a role in the production and control of movement. The nucleus has dense interconnections with the basal ganglia, as well as with other areas of the brain associated with motor control. Electrical stimulation of the pedunculopontine nucleus in the decerebrate cat or rat produces organized locomotor movements. Physiological studies show that the pedunculopontine nucleus modulates its activity in response to locomotion, as well as voluntary arm and eye movements. Degeneration of the pedunculopontine nucleus is seen in post‐mortem brains in humans with Parkinson's disease and Parkinsonian syndromes. In animal models of Parkinson's disease, metabolic changes are seen in the pedunculopontine nucleus, and chemical inhibition or mechanical disruption of the nucleus can produce an akinetic state in animals and man. In this paper we review the literature in support of the suggestion that some of the symptoms of Parkinson's disease are caused by dysfunction of the pedunculopontine nucleus. In accordance with this view, direct stimulation of the nucleus can ameliorate some symptoms of the disease, as demonstrated in both experimental animals and man. © 2008 Movement Disorder Society     

Synchronous radiation‐induced orbital meningioma and multiple cavernomas

Synchronous radiation‐induced tumours are extremely rare. We present the first reported case of synchronous radiation‐induced orbital meningioma and cavernomas of the cerebellum and bilateral basal ganglia, presenting 16 years after ionizing radiation therapy for parietal anaplastic ependymoma, at the age of five. This case again underscores the risks of radiotherapy to children.     

Is Sentinel Lymph Node Biopsy Necessary in Patients Undergoing Prophylactic Mastectomy? A Systematic Review and Meta‐Analysis

The gain by performing sentinel lymph node biopsy (SLNB) during prophylactic mastectomy (PM) is debatable, and we performed a meta‐analysis of existing literature to evaluate that the role of SLNB in subjects undergoing PM. A systematic search was conducted using MEDLINE, PubMed, EMBASE, Current Contents Connect, Cochrane library, Google Scholar, Science Direct, and Web of Science. The search identified 11 relevant articles reporting on patients who underwent SLNB at the time of PM. Data were abstracted from each study and used to calculate a pooled odds ratio (OR) and 95% confidence interval (95% CI). We included 14 studies comprising of 2,708 prophylactic mastectomies. Among 2,708 prophylactic mastectomies, the frequency of occult invasive cancer (51 cases) was 1.8% and the rate of positive SLNs (33 cases) was 1.2%. In 25 invasive cancers at the time of PM were found to have negative SLNs which avoided axillary lymph node dissection (ALND). In seven cases with positive SLNBs were found not to have invasive cancer at the time of PM and needed a subsequent ALND. Most of the patients with positive SLNs had locally advanced disease in the contralateral breast. SLNB may be suitable for patients with ipsilateral, locally advanced breast cancer and is not recommend for all patients undergoing PM.