Hyperprolactinaemia and the empty sella.

Hyperprolactinaemia is an endocrine abnormality seen not infrequently in the population with empty sella; a radiological and anatomical diagnosis of a deformed and enlarged sella turcica. Often there is no associated pathology within the pituitary gland itself, lending to the hypothesis that the empty sella syndrome per se has a yet-to-be defined role in hyperprolactinemia. We report a patient who presented initially with non-specific symptoms of meningeal irritation and viral illness on a long background of galactorrhoea. The patient demonstrated elevated serum prolactin, and a diagnosis of empty sella was made on the basis of MRI findings.

Subarachnoid haemorrhage in a patient with a left temporal arteriovenous malformation and an associated anterior communicating artery aneurysm.

We report a patient who presented with a subarachnoid haemorrhage in the setting of both an arteriovenous malformation and an intracerebral aneurysm. It was felt that the aneurysm had bled and both abnormalities were treated surgically in a sequential manner. The problem of aneurysm combined with arteriovenous malformation is reviewed.

Pallidotomy does not ameliorate abnormal intracortical inhibition in Parkinson's disease.

Motor cortex excitability was assessed in 12 patients with Parkinson's disease (PD) using transcranial magnetic stimulation. Patients were studied when mobile and medicated ("ON") and when immobile after medication withdrawal ("OFF"). Results were compared to eight age-matched and 11 young controls. Cortical excitability was assessed by measurement of resting motor threshold (RMT), intracortical inhibition and cortical silent period duration. In five patients, the studies included assessments following pallidotomy. Cortical excitability was abnormal in patients with PD with reduced RMT in "ON" and "OFF" states, and less effective intracortical inhibition. Pallidotomy did not affect cortical excitability in either "ON" or "OFF" states, indicating that enhanced motor cortex excitability in patients with PD is unaffected by pallidotomy despite clinical improvement in motor scores.

Blister-like aneurysm of the anterior communicating artery.

We report a recent experience with a blister-like aneurysm of the anterior communicating artery and suggest that this entity may be responsible for so-called non-aneurysmal haemorrhage when the distribution of blood is atypical.

Linear accelerator radiosurgery for treatment of vestibular schwannomas in neurofibromatosis 2.

Management of vestibular schwannomas in patients with neurofibromatosis 2 (NF2) balances growth control against preservation of hearing with the primary aim of maintaining patient quality of life. Surgical resection of these lesions carries greater risk of functional deterioration than in sporadic cases. Stereotactic radiosurgery is a less invasive option that provides comparable, if not superior outcomes to resection. Previous studies on the efficacy of stereotactic radiosurgery for vestibular schwannomas in NF2 have reported results from delivery by Gamma Knife systems. The efficacy of linear accelerator (LINAC) delivered treatment has not been specifically addressed. Modelling studies suggest that lesional conformality is superior with Gamma Knife, but clinical studies on sporadic vestibular schwannomas show equivalent results between the two systems. Our experience with LINAC radiosurgery in NF2 reported here shows good long-term growth control in four patients with vestibular schwannomas.

Update of radiosurgery at the Royal Adelaide Hospital.

This is an update of the Royal Adelaide Hospital radiosurgery experience between November 1993 and December 2004 comprising 165 patients with 168 intracranial lesions. Including re-treatment, there were 175 treatment episodes (163 radiosurgery and 12 stereotactic radiotherapy) at an average of 1.3 per month. The commonest lesions were acoustic neuroma (65), arteriovenous malformation (58), solitary brain metastasis (23) and meningioma (14). The clinical features, treatment details and outcome are described. Our results continue to be well within the range reported in the published work. Radiosurgery provides an elegant, non-invasive alternative to neurosurgery and conventional external beam radiotherapy for many benign and malignant brain tumours.

Recurrent subarachnoid haemorrhage from a de novo basilar bifurcation aneurysm: a case report.

Well documented cases of posterior circulation de novo aneurysms are rare. We report a patient who recently presented following a third episode of aneurysmal subarachnoid haemorrhage. Subsequent cerebral angiography revealed a basilar bifurcation aneurysm. This was absent on previous angiographic studies. The current literature on de novo aneurysms is reviewed. The implications for screening are considered.

Ataxic arm movements after thalamotomy for Parkinsonian tremor.

Voluntary finger-nose movements of the arm were analysed in six patients undergoing stereotaxic nucleus ventralis intermedius thalamotomy for relief of severe Parkinsonian tremor. In all cases thalamotomy acutely abolished tremor in the contralateral arm. In the early postoperative phase, ataxia of the arm contralateral to the operated side was also seen. Ataxia was transient, lasting between 7 and 21 days postoperatively. This observation suggests that a lesion of the Vim nucleus interrupts cerebellar input to the thalamus, and supports the concept that abnormal cerebellar activity is an important contributor to the generation of tremor in Parkinson's disease.

Radiosurgery for vestibular schwannomas: preliminary results of the Adelaide experience.

We present the preliminary results of our experience with Linear Accelerator (LINAC) radiosurgery for unilateral vestibular schwannomas. The treatment outcomes of 42 patients with a minimum follow-up of 12 months are reported. An excellent rate of tumour control was achieved with a relatively low complication rate. The current results compare favourably with other reported studies in the literature.

Radiosurgery at the Royal Adelaide Hospital: the first 4 1/2 years' clinical experience.

Radiosurgery refers to the treatment of small lesions localized by stereotactic technology using highly focused radiation. This review utilizes prospectively gathered data from the Royal Adelaide Hospital Radiosurgery unit to summarize experience with the first 62 patients (65 lesions) treated between November 1993 and May 1998. This experience included acoustic neuromas (23 patients), arteriovenous malformations (18), brain metastases (12), meningiomas (6), and glomus tumour, subependymoma, dural arteriovenous fistula (1 each). Although follow up is relatively short, the outcome in terms of morbidity and tumour control is thus far comparable with results reported in the literature. Radiosurgery provides a viable alternative to neurosurgery and conventional external beam radiotherapy for several benign and malignant intracranial lesions.

Acoustic neuroma--surgery or radiosurgery?

This paper discusses surgery and radiosurgery from the author's personal experience with both techniques. Multi-discipline assessment will allow the patient to make an informed decision regarding preferred management.

Voluntary movement after pallidotomy in severe Parkinson's disease.

The mechanisms of improvement in parkinsonian bradykinesia after posteroventral pallidotomy were investigated in 17 patients undergoing unilateral pallidotomy for severe Parkinson's disease. Clinical ratings of 'off' period bradykinesia demonstrated a maximal improvement of 22% 3 months postoperatively. Kinematic assessments of rapid repetitive finger and sequential arm movements were performed after overnight withdrawal of antiparkinsonian medications. There was a bilateral reduction in the inter-onset latency of a two-stage sequential arm movement and a contralateral increase in speed of arm movement after pallidotomy. There was no significant improvement postoperatively in the rhythm, amplitude or speed of repetitive finger movements. The results confirm the clinical impression that pallidotomy improves bradykinesia. This was more evident for complex limb movements, which used attentional strategies and external (visual and auditory) cues, than for repetitive fingertapping movements, which were largely internally generated. Since ablation of the pallidum can only reduce inhibitory pallidal outflow, it is unlikely to restore the normal pallidal influence on thalamocortical motor circuits. Therefore, any improvement in bradykinesia after pallidotomy must be related to mechanisms other than restoration of pallidothalamocortical connectivity. Based on the above observations, we suggest that some of the changes in motor control may be explained by the greater efficacy of external cues in facilitating movement after withdrawal of the abnormal pallidal discharge.

Arctic and Antarctic exploration including the contributions of physicians and effects of disease in the polar regions.

A history of Arctic and Antarctic exploration, whether to find a Northwest Passage, North Pole, or South Pole, is a story of triumph and tribulation. The hardship experienced by polar explorers in the last 1000 years permeates the tales of achievement. Physicians and surgeons have played prominent roles in all major polar explorations. No significant Arctic voyage, particularly in the last 300 years, was made without a member of the party trained in the management of medical emergencies and in basic surgery. During times of health, surgeons functioned as the voyage naturalists with expertise in biology, botany, zoology, and the writing of scientific catalogs. Spurred by our interest and fascination with the history of polar exploration, we reviewed the roles of physicians and natural scientists in Arctic and Antarctic adventures.

Extradural cavernous haemangioma simulating a disc protrusion.

Cavernous haemangiomas confined to the epidural space are rare and are therefore infrequently considered in the differential diagnosis of spinal epidural masses. In order to draw attention to this diagnosis, a case in which an epidural cavernous haemangioma simulates a lateral/foraminal disc protrusion is presented.

Spontaneous pneumocephalus.

Pneumocephalus (PC) is defined as an intracranial gas collection. The majority of cases of PC are secondary to trauma or are iatrogenic. Spontaneous, non-traumatic PC is an uncommon condition. Most cases of spontaneous PC occur in association with infection, neoplasia or disease of otogenic origin. The case of spontaneous PC being presented was felt to have resulted from air being forced into a small deficit in the posterior wall of the sphenoid sinus following an episode of nose blowing.

Surgical palliation of dyskinesiae in Parkinson's disease.

The history of surgical management of Parkinson's disease is outlined. Current practice of thalamotomy and pallidotomy is discussed. Surgical management has re-established its role in the management of Parkinson's disease.

Distal anterior cerebral artery aneurysms: a clinical series.

Thirty patients with distal anterior cerebral artery (DACA) aneurysms were seen at the Royal Adelaide Hospital in the period 1970-1996. There were seven males (23%) and twenty three females (77%) with a mean age of 50 years. The average follow up was 5 years. Multiple aneurysms were present in seven cases (23%). The mean size of aneurysms was 5 mm. There were two post-traumatic aneurysms and one mycotic aneurysm. Out of the 30 cases, 19 presented with subarachnoid haemorrhage from ruptured DACA aneurysms. Eight (42%) of them were in good clinical grade (I or II). Operations were carried out in 25 (83%) patients. All five cases with unruptured aneurysms and the eight patients with good clinical grade had good recovery. In contrast, only six (55%) out of 11 patients with poor clinical grade had good outcome. The overall management mortality for the 19 cases with ruptured aneurysms was 16%. Postoperative complication occurred in two cases (8%), one patient developed deep vein thrombosis and seizures, the other patient had transient upper limb weakness. Although there is a definite trend towards better management outcome in the published series of DACA aneurysms over the years, there is still significant mortality and morbidity in the poor grade patients. Early surgery will prevent the deaths from rebleeding and may allow optimal management of vasospasm.

Neurocysticercosis.

Neurocysticercosis is an infection of the central nervous system by the larvae of the pork tapeworm Taenia sodium. Worldwide it represents the commonest parasitic infection of the central nervous system. However, in Australia, only a small number of cases have been previously recognized. Three cases of neurocysticercosis are reported which illustrate a variety of presentations and diagnostic problems encountered. With the introduction of effective chemotherapeutic agents, current medical and surgical management is reviewed.

Rendu-Osler-Weber syndrome: a current perspective on cerebral manifestations.

Rendu-Osler-Weber syndrome (hereditary haemorrhagic telangiectasia) is a vascular dysplasia characterized by recurrent epistaxis, mucocutaneous telangiectasia and a family history of the disorder. Although rare, it may cause significant morbidity to healthy and young individuals. We report three cases highlighting the cerebral manifestations of this disorder. These cases include cerebral abscess, cerebral haemorrhage and embolic stroke. These cerebral manifestations are due to complications associated with pulmonary arteriovenous fistulae or cerebral vascular malformations. The current management and screening for this disorder are reviewed.

Thalamotomy for parkinsonian tremor.

Thalamotomy for parkinsonian tremor was performed in 25 patients. A good outcome was achieved in 66% of cases. Three patients sustained a significant new deficit. Stimulation through the lesioning electrode provided an adequate means of corroboration of target localisation.