Subthalamic Nucleus Activity during Cognitive Load and Gait Dysfunction in Parkinson's Disease.

Background: Gait freezing is a common, disabling symptom of Parkinson's disease characterized by sudden motor arrest during walking. Adaptive deep brain stimulation devices that detect freezing and deliver real-time, symptom-specific stimulation are a potential treatment strategy. Real-time alterations in subthalamic nucleus firing patterns have been demonstrated with lower limb freezing, however, whether similar abnormal signatures occur with freezing provoked by cognitive load, is unknown.

Hitting the brakes: pathological subthalamic nucleus activity in Parkinson's disease gait freezing.

Gait freezing is a complex and devastating paroxysmal motor arrest commonly suffered in Parkinson's disease that causes significant impairment to mobility, commonly resulting in falls and subsequent injury. The neurobiological basis of gait freezing in Parkinson's disease is poorly understood and thus, currently available therapies are partially effective at best. We used a validated virtual reality gait paradigm to elicit freezing behaviour intraoperatively in eight patients undergoing subthalamic nucleus deep brain stimulation surgery while microelectrode recordings were obtained.

Silent corticotroph adenoma with adrenal cortical choristoma: a rare but distinct morphological entity.

This report describes a case of pituitary adenoma with interspersed adrenal cortical cells. The pituitary cells were confirmed to be corticotrophs with Tpit and adrenocorticotropic hormone immunohistochemistry, whereas the adrenal cortical cells were verified to be such with steroidogenic factor-1 (SF-1), inhibin, calretinin, and Melan A staining. The presence of normal adrenal cortical cells in the heterotopic location of the sella fulfills the definition of choristoma.

Severe agitation following deep brain stimulation for parkinsonism.

The use of deep brain stimulation has become increasingly common for the treatment of movement disorders, including Parkinson disease. Although deep brain stimulation is generally very successful in alleviating the extrapyramidal symptoms of Parkinson disease, side effects can occur. This case report describes a patient presenting to the emergency department in a state of extreme aggression 3 days after a change in the parameters of his bilateral subthalamic nucleus stimulator.

Medial forebrain bundle stimulation as a pathophysiological mechanism for hypomania in subthalamic nucleus deep brain stimulation for Parkinson's disease.

Objective: Hypomania accounts for approximately 4% to 13% of psychotropic adverse events during subthalamic nucleus (STN) deep brain stimulation (DBS) for Parkinson's disease. Diffusion of current into the inferior and medial "limbic" STN is often reported to be the cause. We suggest a different explanation, in which the coactivation of the medial forebrain bundle (MFB), outside the STN, leads to hypomania during STN DBS.

Intraventricular rhabdoid meningioma.

Rhabdoid meningioma is a rare variant of meningioma, often found in tumour recurrences. We report a 55-year-old woman with a history of intraventricular fibroblastic meningioma, who developed headache and tinnitus 5 years after complete resection of the initial tumour. Imaging confirmed a recurrent tumour in the intraventricular location.