Deep brain stimulation for Parkinson disease in Australia: current scientific and clinical status.

There is currently no cure for Parkinson disease (PD). Disease management is directed primarily at motor symptom relief, but the impact of non-motor symptoms associated with PD should not be underestimated. Medical and surgical treatment options aim to increase functional independence and quality of life. Deep brain stimulation (DBS) has proven to be a safe, effective and cost-efficient surgical treatment option. In 2009, the Australian referral guidelines, developed to provide a synopsis of DBS therapy for PD, were introduced, and since then novel findings have been reported regarding the timing of intervention, target selection and symptom management. Our aim is to provide an update of DBS for PD in Australia. Intervention at earlier stages of the disease can potentially improve quality of life over a longer period with greater possibilities for meaningful social and professional contributions. For less responsive motor symptoms (e.g. freezing of gait, postural instability), the pedunculopontine nucleus has emerged as a promising new surgical target. Traditional PD treatment is focused on improvement of motor symptoms, but the disorder is also characterised by non-motor symptoms, often undiagnosed or undisclosed, that have the potential to impact quality of life to a greater extent than motor symptoms. It is essential to identify and routinely monitor for non-motor symptoms as they can emerge at all stages of the disease or can result from treatment. Many of these current advances require long-term monitoring of treatment outcomes to improve future clinical practice, refine patient selection and ensure best patient outcomes.

Effects of subthalamic deep brain stimulation on noun/verb generation and selection from competing alternatives in Parkinson's disease.

BACKGROUND AND AIMS: Impaired generation of verbs relative to nouns has been reported in Parkinson's disease (PD) and has been associated with the frontal pathophysiology of PD. The aim of the present study was to measure noun/verb generation abilities in PD and to determine whether noun/verb generation is affected by stimulation of the subthalamic nucleus (STN). PATIENTS AND METHODS: 8 participants who had been diagnosed with PD and had received surgery for deep brain stimulation (DBS) of the STN as well as 15 control participants completed a noun/verb generation task with four probe-response conditions-namely, noun-noun, verb-noun, noun-verb and verb-verb conditions. Patients with PD were assessed while receiving STN stimulation and without stimulation. RESULTS: During the off stimulation condition, patients with PD presented with a selective deficit in verb generation compared with control participants. However, when receiving STN stimulation, patients with PD produced significantly more errors than controls during the noun-noun and verb-verb conditions, supporting evidence from previous studies that STN stimulation modulates a frontotemporal network associated with word generation. Finally, errors during verb generation were significantly correlated with item selection constraint (ie, the degree to which a response competes with other response alternatives) in the on stimulation condition, but not the off stimulation condition. CONCLUSION: Our results suggest that STN stimulation affects the ability to select from many competing lexical alternatives during verb generation.

C1-C2 transarticular screw fixation for treatment of C1-C2 instability.

C1-C2 instability has traditionally been treated by C1-C2 posterior wiring and bone grafting. However, this technique has an incidence of non-union which may exceed 10%. Transarticular screw fixation has developed as a technique of providing increased strength of fixation of C1-C2 arthrodesis, while at the same time avoiding the need for postoperative halo bracing and avoiding the risk of neurological injury associated with the passage of sublaminar wires. We present a retrospective review of 12 patients with C1-C2 instability treated by C1-C2 transarticular screw fixation. Eight patients underwent this procedure as primary treatment, and 4 after a failed Gallie fusion. Five patients had a cruciate ligament rupture, 5 had an odontoid process fracture, 1 had os odontoideum, and 1 had rheumatoid instability. There was no surgical morbidity or mortality and, at a mean follow up of 12.1 +/- 3 months (range 8-14 months), all patients had achieved solid fusion, and all neurological symptoms referable to the instability had resolved. C1-C2 transarticular screw fixation has been shown to be safe and effective and has a number of advantages when compared to traditional posterior wiring techniques. We recommend that this technique be considered as a primary treatment of C1-C2 instability.

C1-C2 posterior cervical fusion: long-term evaluation of results and efficacy.

Posterior wiring techniques are the most commonly used methods of achieving C1-C2 arthrodesis. Recently, transarticular screw fixation and interlaminar clamping have been advocated to achieve more secure fixation. A retrospective review of patients undergoing C1-C2 fusion for nonneoplastic disease was undertaken at the University of Toronto Hospital, with the aim of determining the long-term outcome of the selected procedures. Thirty-two patients underwent 36 procedures from 1986 to 1992, with a mean follow-up of 4.7 +/- 2.2 years (range, 2.0-8.0 yr). The most common disease processes were odontoid fracture (18 patients), transverse atlantal ligament injury (5 patients), os odontoideum (5 patients), and rheumatoid C1-C2 instability (3 patients). Thirty-one Gallie fusions, one Brooks-Jenkins fusion, two transarticular screw fusions, and two Halifax clamp applications were performed. Six (19%) of Gallie/Brooks-Jenkins fusions failed. These occurred with os odontoideum (three patients), Type II odontoid fracture (two patients), and transverse atlantal ligament injury (one patient). All transarticular screw and Halifax clamp procedures resulted in successful fusions. Two procedures (6%) resulted in new neurological deficit; both of these patients underwent posterior wiring for os odontoideum. This study suggests that Type II odontoid fractures may be successfully managed by a posterior wiring technique alone. Rheumatoid C1-C2 instability may be managed by posterior wiring supplemented with halo immobilization. Transarticular screw fixation has several potential advantages as a technique for C1-C2 arthrodesis and, in particular, may be appropriate for os odontoideum that had a high failure rate (75%) with conventional posterior wiring, even when this was supplemented with halo bracing.

Peri-operative anticoagulant effects of heparinization for carotid endarterectomy.

The question of whether or not to reverse heparin following carotid endarterectomy is a topic of debate. The potential reduction of the risk of thrombosis at the endarterectomy site with non-reversal has to be measured against a potential increase in the risk of wound haematoma. This study prospectively followed activated clotting time (ACT) of 42 consecutive patients undergoing carotid endarterectomy. A standard heparin dose of 100 units/kg was used, and heparin reversal was employed only if the wound appeared excessively haemorrhagic at the procedure's completion. Heparin was reversed in 11 patients. Following heparin administration, ACT increased to a mean 2.72 +/- 0.09 times baseline (range 1.84-4.07), and fell with time, until at 3 h after heparin administration mean ACT in the non-reversed patients was 1.48 +/- 0.03 times baseline (range 1.1-2.03). There was one postoperative neurological event (2%), a contralateral hemisphere stroke. No patient developed a frank wound haematoma requiring evacuation, although three patients (7% of the total study group, 9% of patients not receiving heparin reversal) developed neck swelling and symptoms of airway compromise, and were intubated. Measurements of ACT suggest that a heparin dose of 100 units/kg achieves an adequate anticoagulant level in the operative and early postoperative phase, when thrombosis is most likely to occur, and is not associated with an increased risk of wound haematoma. If heparin is to be selectively reversed in patients felt to be at high risk of postoperative haematoma, the decision should be based on an objective measurement such as ACT, and not the surgeon's impression of wound haemostasis.

Percutaneous transluminal angioplasty for cerebral vasospasm after subarachnoid hemorrhage.

OBJECTIVE: To assess the efficacy of percutaneous transluminal angioplasty. DESIGN: A retrospective case study covering the period January 1990 to December 1992. SETTING: A tertiary-care referral centre. PATIENTS: Thirteen patients, ranging in age from 23 to 57 years, who had suffered an aneurysmal subarachnoid hemorrhage and subsequent symptomatic vasospasm that had not responded to aggressive medical therapy. INTERVENTION: Percutaneous transluminal angioplasty of spastic cerebral arteries MAIN OUTCOME MEASURES: Neurologic improvement (improved level of consciousness or resolution of focal deficit) immediately after angioplasty and functional status at 6 months after angioplasty. RESULTS: Four (31%) patients showed neurologic improvement immediately after angioplasty. At 6 months, 5 (38%) of the 13 were independent, 2 (15%) were dependent (severely disabled), and 6 (46%) had died. Poor clinical grade at the time of angioplasty was associated with a poor outcome. CONCLUSIONS: Percutaneous transluminal angioplasty appears to be a safe procedure that is beneficial in some patients with symptomatic vasospasm refractory to aggressive hypervolemic, hypertensive therapy. The best results likely are obtained in patients of good clinical grade in whom new neurologic deficits have not become established, and angioplasty should not be delayed if medical therapy does not rapidly reverse the symptoms of vasospasm.

Bilateral third cranial nerve palsies in association with a ruptured anterior communicating artery aneurysm.

Third cranial nerve palsy occurring in a patient with an intracranial aneurysm is typically unilateral and associated with an internal carotid-posterior communicating or distal basilar artery aneurysm. In this report a patient with bilateral third cranial nerve palsies associated with rupture of an anterior communicating artery aneurysm is described. Raised intracranial pressure without brain herniation and compression of the third nerves within the perimesencephalic cisterns by focal subarachnoid clot are suggested as possible underlying mechanisms of the palsies, which showed complete recovery at 4 months after the hemorrhage and subsequent early aneurysm repair.

Surgical referral for carotid artery stenosis--the influence of NASCET. North American Symptomatic Carotid Endarterectomy Trial.

A retrospective review was undertaken of 139 consecutive patients with presumed carotid artery stenosis referred to a vascular neurosurgeon. The review period included three years prior and one year subsequent to the publication of the North American Symptomatic Carotid Endarterectomy Trial (NASCET) preliminary results showing surgery to be superior to best medical therapy for patients with symptomatic, high grade (> 70% linear diameter) carotid stenosis. The aims of this analysis were to determine any changes in the referral pattern following the NASCET publication (post-NASCET), and to examine the use and reliability for surgical decision making of pre-referral carotid artery imaging. Patient referral rate increased markedly post-NASCET, particularly from neurologists. There was a trend for more post-NASCET referrals to be for high grade stenosis and fewer referrals to be for intermediate grade (30-69% linear diameter) stenosis, although continued referral of patients with intermediate grade stenosis is desirable as randomization into NASCET continues for this group of patients. Ninety-six patients (69%) were referred with carotid duplex ultrasonography having been performed. There was poor correlation of these results with angiography, which remains necessary for planning management. A majority of patients (65%) referred to this surgical practice did not come to surgery.

Angiographic vasospasm in a contemporary series of patients with aneurysmal subarachnoid haemorrhage.

Over the last decade there have been significant changes in the management of patients with aneurysmal subarachnoid haemorrhage (SAH). Many of these changes, such as haemodilutional, hypervolaemic, hypertensive therapy and the use of calcium channel blockers, have been directed at the prevention and treatment of vasospasm. The angiograms of a contemporary series of 56 consecutive surgically treated patients with aneurysmal SAH were examined to compare angiographic vasospasm with that seen in historical studies. The time course of angiographic vasospasm was found to be broadly similar to that reported in previous studies, with onset after day 3 following SAH, maximal narrowing during the second week, and resolution after day 16. The times of peak narrowing and resolution were slightly earlier in previous studies. 30% of patients had clinical vasospasm (delayed neurological deficit for which other causes had been excluded), and these patients had a trend to more severe angiographic narrowing than those without clinical vasospasm, particularly in the second week following SAH. 44 angiograms were performed between days 1-3 post SAH and repeated between days 4-16. 95% of these showed arterial narrowing at the second angiogram. Patients not achieving an independent outcome tended to have had both more clinical vasospasm and more severe angiographic spasm than those achieving independence. It is concluded that angiographic vasospasm remains a common occurrence in the modern era, and continues to be associated with clinical events and a poor outcome.

The effect of surgery on the severity of vasospasm.

Intracranial aneurysm surgery performed between 4 and 12 days after subarachnoid hemorrhage (SAH) has been associated with an increased risk of delayed cerebral ischemia and poor outcome compared to surgery performed before or after this time. To investigate whether this increased risk is due to aggravation of vasospasm, the angiograms obtained before and after surgery in 56 patients operated on at various times after aneurysmal SAH were studied. Vasospasm was quantitated by measuring the diameters of intracranial arteries and expressed as the ratio of the diameters of the intracranial arteries to the diameter of the extracranial internal carotid artery. Aggressive surgical clot removal was not performed at surgery. To correct for differences in prognostic factors for vasospasm between patients operated on at different times after SAH, multiple regression analysis was performed using the arterial diameter ratio during vasospasm as the dependent variable and the prognostic factors for vasospasm, including the time of surgery, as independent variables. Equations predicting the severity of vasospasm could be generated using the clinical grade on admission, patient age, and preoperative arterial diameter ratio. The time of surgery had no effect on vasospasm. Cerebral infarction due to vasospasm developed in five (15%) of 34 patients operated on within 3 days after SAH and in four (20%) of 20 operated on between 4 and 12 days after SAH (p = 0.66). A good outcome for these two groups was achieved in 88% and 85%, respectively (p = 1.00). These results suggest that the timing of surgery does not affect the development of vasospasm. Any increased risk of cerebral ischemia associated with surgery performed between 4 and 12 days after SAH is due to factors other than aggravation of vasospasm.

Deep cerebral venous system thrombosis: case report.

A 38-year-old woman with thrombosis of the deep cerebral venous system, presumed to be secondary to the use of the oral contraceptive pill, is reported. The use of cerebral angiography and magnetic resonance imaging in establishing the diagnosis and management strategies is discussed. It is concluded that magnetic resonance imaging is an appropriate investigative modality for diagnosis and therapeutic decision making, and that, as with superficial cerebral dural sinus and venous thrombosis, anticoagulation is a safe and effective therapy.

Intracranial epidural abscess: a report of three cases.

Intracranial epidural abscess is an uncommon but potentially life-threatening condition requiring prompt recognition and management. Most commonly it arises secondary to infection in the paranasal sinuses, mastoid air cells or the middle ear. It has also been described following craniotomy and trauma. This report describes three cases reported to our institution over a 15 month period, two associated with frontal sinusitis and one with no obvious predisposing factor.

Adrenocorticotropic hormone-secreting pituitary tumor associated with pregnancy: case report.

A patient with an adrenocorticotropic hormone-secreting pituitary adenoma diagnosed at the same time as pregnancy is reported. Treatment was by transsphenoidal tumor resection, which has only been described once previously in such a case. Treatment rationale is discussed, and transsphenoidal tumor resection is recommended as the therapy of choice.

A two-year survey of aneurysmal subarachnoid haemorrhage.

OBJECTIVE: To analyse the demographic characteristics and outcomes of patients with rupture of an intracranial aneurysm--to make a comparison with other published results, and to determine whether improvements in management can be made. DESIGN: A retrospective review of the records of a consecutive series of 102 patients admitted to a neurosurgical unit in 1988 and 1989. SETTING: The Royal Brisbane Hospital neurosurgical unit. PATIENTS: Sixty-three women and 39 men with subarachnoid haemorrhage after rupture of an intracranial aneurysm. MAIN RESULTS: Sixty-three patients achieved independence and 32 died. Of those 78 patients who were able to be offered surgery, 60 (77%) became independent. The outcome was significantly influenced by the neurological condition of the patient on admission to hospital (P less than 0.01). CONCLUSION: A speedier referral of these patients to a neurosurgical unit may lead to an improvement in outcome.