Deep brain stimulation for Parkinson's disease: Australian referral guidelines.

The advent of deep brain stimulation (DBS) has been an important advance in the treatment of Parkinson's disease (PD). DBS may be employed in the management of medication-refractory tremor or treatment-related motor complications, and may benefit between 4.5% and 20% of patients at some stage of their disease course. In Australia, patients with PD are reviewed by specialised DBS teams who assess the likely benefits and risks associated with DBS for each individual. The aim of these guidelines is to assist neurologists and general physicians identify patients who may benefit from referral to a DBS team. Common indications for referral are motor fluctuations and/or dyskinesias that are not adequately controlled with optimised medical therapy, medication-refractory tremor, and intolerance to medical therapy. Early referral for consideration of DBS is recommended as soon as optimised medical therapy fails to offer satisfactory motor control.

Long-term follow-up of DBS of thalamus for tremor and STN for Parkinson's disease.

In 1994 we commenced deep brain stimulation (DBS) of the thalamus for patients with severe tremor. This was done under the guidance of Professor Alim Benabid from Grenoble, France, who pioneered the technique. In the beginning we commenced DBS of the thalamus for patients with severe tremulous Parkinson's disease, essential tremor, and in one case, severe post-traumatic tremor. In all, we had 28 patients for whom the procedure was performed for tremulous Parkinson's disease, six patients with essential tremor and one patient with post-traumatic tremor. In 1997, again under the guidance of Professor Benabid, we commenced bilateral subthalamic nucleus stimulation (STN) for patients with severe Parkinson's disease. We were the second unit in Australia to become established for these procedures. A total of 45 patients have undergone STN DBS and have been followed up on a regular basis by the same neurologist (DOS). The surgical complications and long-term complications, including hardware problems will be reviewed retrospectively, as well as the long-term benefits of these surgical procedures.

Partial lesion of thalamic ventral intermediate nucleus after chronic high-frequency stimulation.

A 73-year-old man with Parkinson's disease underwent thalamic stimulation for disabling tremor with excellent results only when stimulation on. Post-mortem neuropathology (7 years postoperatively) revealed 60% cell loss within 0.5 mm of the electrode tip. Tremor improvement was attributable to chronic stimulation, not microthalamotomy.

Xanthomatous pituitary lesions: a report of two cases and review of the literature.

We describe two young men with cystic pituitary enlargement on magnetic resonance imaging (MRI) causing hypopituitarism. The first patient presented acutely unwell with headache and vomiting associated with anterior and posterior pituitary dysfunction. The second patient presented with hypopituitarism after a long history of hypogonadism. In both cases yellow/brown fluid was found at surgery and histological examination revealed inflammatory infiltrate with foamy histiocytes, lymphocytes and multinucleated giant cells containing cholesterol clefts. Full recovery of pituitary function occurred after surgery in the first but not the second patient. The first case is the first documented case of xanthomatous hypophysitis with recovery of pituitary function following surgery. The cases differed in duration of disease, as indicated by the long history of symptoms, the histological finding of marked fibrosis and the lack of recovery of pituitary function in the second. Xanthomatous pituitary lesions categorized in the literature as xanthomatous hypophysitis, xanthogranulomatous hypophysitis and xanthogranuloma of the sellar region have overlapping histological features. Our two cases revealed histological features that do not fit completely into any of the categories but share features of all three. These findings suggest that the various xanthomatous lesions of the sellar region may be a spectrum of a common inflammatory process rather than distinct pathological entities.

Postmortem analysis of bilateral subthalamic electrode implants in Parkinson's disease.

This is the second neuropathological report detailing bilateral electrodes targeting the subthalamic nucleus (STN) in idiopathic Parkinson's disease (PD). The patient presented with unilateral tremor-dominant parkinsonism. Bilateral STN stimulation was carried out 7 years later due to significant disease progression and severe motor fluctuations. The patient exhibited bilateral improvements in rigidity and bradykinesia both intraoperatively and postoperatively. The patient died 2 months later from aspiration pneumonia. Neuropathological examination confirmed both the diagnosis of PD and the electrode placements. The tip of the left electrode was located medially and posteriorly in the left STN and the tip of the right electrode entered the base of the thalamus/zona incerta immediately above the right STN. Tissue changes associated with the subthalamic electrode tracts included mild cell loss, astrogliosis, and some tissue vacuolation. Our postmortem analysis indicates little tissue damage associated with STN stimulation for PD.