Cerebellar strokes: a clinical outcome review of 79 cases.

INTRODUCTION: Cerebellar infarcts and haemorrhages are relatively uncommon, accounting for less than 10% of all strokes. The objective of the present study was to quantify and compare the outcomes of patients with cerebellar infarct and those of patients with cerebellar haemorrhage, as well as to identify the risk factors that predict poor outcome in patients with cerebellar stroke. METHODS: We retrospectively reviewed the medical records of consecutive patients admitted to National University Hospital, Singapore, between 2004 and 2006, within one week of cerebellar stroke onset. Baseline data included demographics, concomitant comorbidities, and the presence or absence of brainstem compression and hydrocephalus (on computed tomography or magnetic resonance imaging). The Glasgow Outcome Scale and modified Rankin Score were used to assess outcome at discharge and at six months after discharge. RESULTS: A total of 79 patients with cerebellar stroke were admitted during the study period. Of these 79 patients, 17.7% died and 31.6% had poor outcomes at six months after discharge. Patients with cerebellar haemorrhage were found to be more likely to have poor outcomes as compared to patients with cerebellar infarct, both at discharge (odds ratio [OR] 4.3, 95% confidence interval [CI] 1.3-14.1) and at six months after discharge (OR 5.2, 95% CI 1.6-17.2). When compared to small lesions (< 5 cm(3)), lesions > 20 cm(3) were significantly associated with poorer outcomes and the development of hydrocephalus and brainstem compression. CONCLUSION: Cerebellar strokes are a significant cause of morbidity and mortality. The outcomes of patients with cerebellar haemorrhage are more likely to be worse than those of patients with cerebellar infarct.

Intracranial pial arteriovenous fistula in infancy: a case report and literature review.

Intracranial pial arteriovenous fistulas (AVF) are rare vascular malformation especially in the first 2 years of life. The pathology in this age group is associated with greater morbidity and mortality. We report a rare case of 36-day-old male infant with a pial AVF associated with an arterial aneurysm, who presented with intraventricular hemorrhage and hydrocephalus. In addition, an online review of the literatures on pediatric pial AVF was performed using PubMed on published case reports and articles from 1980 to April 2013.

Management of ruptured intracranial aneurysms in the post-ISAT era: outcome of surgical clipping versus endovascular coiling in a Singapore tertiary institution.

INTRODUCTION: The results of the International Subarachnoid Aneurysm Trial (ISAT) in 2002 have significantly influenced the management of ruptured intracranial aneurysms. There is now an established shift worldwide toward endovascular coiling as the initial treatment of choice. We assessed the outcomes of patients admitted to our institution for aneurysmal subarachnoid haemorrhage (SAH), comparing the outcomes of patients (World Federation of Neurosurgical Societies [WFNS] grades 1-3) who underwent surgical clipping versus those who underwent endovascular coiling. METHODS: We retrospectively reviewed patients admitted to the National University Hospital for SAH secondary to ruptured intracranial aneurysm in 2005-2009. Patients were divided into two groups - clipping and coiling. Data on individual demographics, comorbidities, Fisher grading and Glasgow Outcome Scale scores were collected for the two groups and subjected to relevant statistical analyses. RESULTS: Of the 133 patients admitted for nontraumatic SAH, 89 had ruptured aneurysms. Among the 56 patients classified as WFNS grades 1-3, 23 underwent coiling while the remaining 33 underwent clipping. A significant association was found between Fisher grade and the likelihood of developing hydrocephalus in these patients. CONCLUSION: Although we acknowledge the presence of management bias in our institution, our findings were similar to those of the ISAT trial. Upon correlation between our results and current evidence-based findings, our findings show that clipping provides similar long-term outcomes as endovascular coiling. In the event that an aneurysm is deemed unsuitable for coiling, clipping remains an effective option.

Lethal intratumoral haemorrhages of brain metastases during radiosurgery: case reports and literature review.

Gamma Knife surgery (GKS) is an effective and important treatment modality in the management of brain metastases. The short-term complication rate is low and the tumour control rate high. Complications caused by acute radiation-induced oedema are rare and usually benign. In this article, two cases of lethal haemorrhagic event immediately following GKS are described from two centres, which had prompted us to review the literature.

Correlation of the long-term neurological outcomes with completeness of surgical evacuation in spontaneous supratentorial intracerebral haemorrhage: a retrospective study.

INTRODUCTION: The treatment of primary spontaneous supratentorial intracerebral haemorrhage (ICH) by evacuation is not supported by randomised controlled trials. We investigate the effectiveness of the completeness of surgical evacuation of spontaneous supratentorial ICH with respect to the functional neurological outcome and mortality. METHODS: A retrospective review of patients who underwent supratentorial ICH evacuations in the Neurosurgical Unit of the National University Hospital, Singapore, between January 2002 and December 2005 was conducted. Preoperative and postoperative computed tomography images were compared, and the patients or their family members completed follow-up questionnaires two years post surgery, in order to assess the neurological outcome. RESULTS: The patients were subdivided into two groups based on the Glasgow Outcome Scale and haematoma volume. Patients with small pre-evacuation haematoma had a median percentage change in volume and a midline shift of 97.63 percent and 63 percent, respectively. Patients with a large haematoma volume had a median percentage change in volume and midline shift of 99.54 percent and 100 percent, respectively (the p-values for percentage change in volume and midline shift are 0.764 and 0.742, respectively). The median percentage change in volume for the poor outcome subgroup was 97.63 percent, compared to 100 percent for the good outcome subgroup (p-value is 0.288). The median change in midline shift in the poor and good outcome subgroups was 63 percent and 100 percent, respectively (p-value is 0.576). CONCLUSION: Although not statistically significant with regard to the completeness of haematoma evacuation, a trend toward better outcome with more complete evacuation is observed with ICH.

Use of Osteoplug polycaprolactone implants as novel burr-hole covers.

INTRODUCTION: The aim of this study was to evaluate the outcome of Osteoplug, a novel biodegradable polymer burr-hole cover implant, used in patients with burr holes done for drainage of chronic subdural haematoma. METHODS: 12 patients with chronic subdural haematoma had Osteoplug implants inserted into their burr holes after evacuation of the haematoma. Osteoplug is a biodegradable polycaprolactone implant with a mushroom-button shape, designed specifically to fit into a 14-mm diameter burr hole. It has an upper rim of 16-mm diameter and a body diameter of 14 mm, with a honeycomb-like architecture of 400-600 mum pore size. The Osteoplug snaps onto the 14-mm diameter burr hole snugly after the evacuation of the liquefied haematoma is done. All 12 patients were followed up for a period ranging from ten months to two years (mean 16 months) postoperatively. They were evaluated for their clinical, radiological and cosmetic outcomes. RESULTS: Osteoplug provided good cosmesis by preventing unsightly depressions over the skull postoperatively in all the 12 patients. Postoperative computed tomography, done at one year, showed signs of good osteointegration into the surrounding calvarial bone, with multifoci mineralisation throughout the scaffold in one patient. There was no case of infection or any adverse systemic reaction noted. Patient satisfaction was high. CONCLUSION: The Osteoplug polycaprolactone burr-hole covers are suitable, biodegradable implants with good medium-term results. They provide an ideal scaffold for osteogenesis and excellent cosmesis. There were no adverse events in all 12 patients, with a mean follow-up of 16 months.

MR spectroscopy in sinus mucocele: N-acetyl mimics of brain N-acetylaspartate.

We describe MR spectroscopy in 2 patients with frontal sinus mucoceles that showed a dominant metabolite peak at 2.0-ppm chemical shift, simulating N-acetylaspartate (NAA) of normal neuronal tissue. In vitro analysis of postsurgical mucocele samples confirmed that the signal at 2.0 ppm was arising from the methyl moiety of an N-acetyl compound. This is probably caused by N-acetylgalactosamine or N-acetylglucosamine, which are glycoproteins found in normal respiratory mucus produced by the paranasal sinus epithelium.

Non-traumatic spontaneous acute epidural haematoma -- report of two cases and review of the literature.

Epidural haematomas are usually associated with preceding head trauma. The entity of non-traumatic spontaneous acute epidural haematoma is rare and most commonly occurs in the presence of infectious disease. It can also occur in the presence of coagulopathy, vascular malformations of the dura mater and haemorrhagic tumours. Sickle cell disease, systemic lupus erythematosus, open heart surgery and haemodialysis have also been implicated as causative factors. The authors report two cases of spontaneous epidural haematomas (one of unknown aetiology and one from a coagulation disorder) and discuss the aetiological agents involved in this rarely described condition.

Patients who talk and deteriorate: a new look at an old problem.

BACKGROUND AND METHODS: We sought to review established prognostic indicators applied to Asian population, and to identify new risk factors for deterioration in patients who talked and deteriorated after traumatic brain injury (TBI). This retrospective study used our prospectively maintained TBI database. From August 1999 to July 2001, 324 patients were admitted to the neurosurgical intensive care unit (ICU). Thirty-eight patients (11.8%) talked between injury and subsequent deterioration into coma. Independent outcome predictors were studied. RESULTS AND CONCLUSION: Fourteen patients had subdural haematomas, 9 extradural haematomas, 19 contusions/haematomas and 3 subarachnoid haemorrhages. 81.5% of the patients had mass lesions potentially requiring surgery. Twenty patients had good functional recovery at 6 months (Glasgow Outcome Score 4 and 5); 18 were dead or vegetative. Age, gender, type of intracranial lesion and presence of coagulopathy were significantly correlated with outcome. Intracranial haematomas continue to be most significant in patients who talk and deteriorate. Coagulopathy was the strongest prognostic predictor of poor outcome with fibrinolytic parameters being reliable prognostic markers of head injury. Early identification, continued monitoring and treatment of coagulopathy should be our new look at improving outcome of these patients.

Hypertensive basal ganglia hemorrhage: a prospective study comparing surgical and nonsurgical management.

BACKGROUND: The optimal treatment of hypertensive supratentorial intracerebral hemorrhage is still debated. Some studies have shown no improvement in survival or functional outcome after surgery when compared to conservative management while others have shown otherwise. METHODS: This study was a prospective trial, matching patients for hematoma volume and Glasgow Coma score on admission. RESULTS: There were a total of 34 patients. Seventeen were treated conservatively and 17 surgically. There was no significant difference between the two groups in terms of age, GCS, hematoma volume, or presence of intraventricular blood. At 3, 6, and 12-month follow-up, they were assessed using the Modified Barthel Index by a blinded observer. There was no difference between the two groups at 3, 6, or 12 months follow-up. The mortality rate was similar in the two groups. CONCLUSIONS: Based on this study and review of the literature, we cannot recommend routine evacuation of clots to treat these hemorrhages.

Management of haemorrhagic stroke with hyperbaric oxygen therapy--a case report.

Hyperbaric oxygen therapy (HBOT) has been used in the treatment of cerebral ischaemia with positive effects on tissue oxygenation. We present a case of haemorrhagic stroke treated successfully with HBOT and review the literature on its role in cerebrovascular disease.

Nitric oxide and subarachnoid hemorrhage: elevated level in cerebrospinal fluid and their implications.

OBJECTIVE: Nitric oxide (NO) plays an important role in the pathogenesis of neuronal injury after brain ischemia, and decreased levels of NO have been implicated in the pathogenesis of vasospasm after subarachnoid hemorrhage (SAH). In this study, we measured the ventricular cerebrospinal fluid (CSF) NO levels in patients with SAH and correlated the levels with clinical grade and middle cerebral artery velocities measured with transcranial Doppler ultrasound. METHODS: All patients with spontaneous SAH documented on computed tomography and with an external ventricular drain inserted within 24 hours of hemorrhage were included in the study. A total of 16 patients were studied between August 1999 and August 2000. CSF was collected serially at the time of surgery and subsequently at daily intervals. It was collected during the time that the external ventricular drain remained patent and in situ. NO levels were measured by photometric analysis by using a nitrite/nitrate assay kit (Cayman Chemical, Ann Arbor, MI). RESULTS: The peak NO level in patients with SAH ranged from 9.96 to 168.16 micromol, with a median of 36.93 micromol. The levels were significantly elevated as compared with the control group (5.16 micromol, P < 0.05). The median NO level in patients with poor-grade SAH was 67.14 micromol as compared with 27.42 micromol in patients with good-grade hemorrhage (P < 0.05). No correlation was seen between CSF NO levels and middle cerebral artery velocities. The median NO level was 33.2 micromol in patients with a poor outcome as compared with 30.25 micromol in patients with a good outcome (P > 0.05). CONCLUSION: This study showed that NO levels are elevated after spontaneous SAH, and the degree of elevation is higher in patients with poor-grade SAH.

The leukocyte common antigen-related protein tyrosine phosphatase receptor regulates regenerative neurite outgrowth in vivo.

Drosophila and leech models of nervous system development demonstrate that protein tyrosine phosphatase (PTP) receptors regulate developmental neurite outgrowth. Whether PTP receptors regulate neurite outgrowth in adult systems or in regenerative states remains unknown. The leukocyte common antigen-related (LAR) receptor is known to be present in rodent dorsal root ganglion (DRG) neurons; therefore, the well established model of postcrush sciatic nerve regeneration was used to test the hypothesis that LAR is required for neurite outgrowth in the adult mammalian nervous system. In uninjured sciatic nerves, no differences in nerve morphology and sensory function were detected between wild-type and LAR-deficient littermate transgenic mice. Sciatic nerve crush resulted in increased LAR protein expression in DRG neurons. In addition, nerve injury led to an increase in the proportion of LAR protein isoforms known to have increased binding affinity to neurite-promoting laminin-nidogen complexes. Two weeks after nerve crush, morphological analysis of distal nerve segments in LAR-deficient transgenic mice demonstrated significantly decreased densities of myelinated fibers, decreased axonal areas, and increased myelin/axon area ratios compared with littermate controls. Electron microscopy analysis revealed a significant twofold reduction in the density of regenerating unmyelinated fibers in LAR-/- nerves distal to the crush site. Sensory testing at the 2 week time point revealed a corresponding 3 mm lag in the proximal-to-distal progression of functioning sensory fibers along the distal nerve segment. These studies introduce PTP receptors as a major new gene family regulating regenerative neurite outgrowth in vivo in the adult mammalian system.

Advances in neurointensive care.

PURPOSE: To highlight recent advances in neurological and neurosurgical intensive care. DATA SOURCES: A MEDLINE search was conducted from January 1980 to August 2000. Keywords included intensive care, head injury, subarachnoid haemorrhage, status epilepticus, myasthenic crisis, Guillain-Barre syndrome and stroke. All articles in English were considered for review. Additional articles were identified from the references of the retrieved articles and cross-referencing selected articles. DATA EXTRACTION: All clinical studies, review articles and abstracts were reviewed. DATA SYNTHESIS: Rapid advances in neurological and neurosurgical intensive care in the last decade have led to the development of specialised neurointensive care units with joint ventures between neurology and neurosurgery. Work in these units have contributed immensely to our understanding of the pathophysiology and management of acute brain injury. The principles of intensive care management include amelioration or reversal of brain injury and preservation of normal neural tissue. Treatment algorithms are possible with the aid of intense clinical and neurophysiologic monitoring. Ongoing clinical and basic science research may provide new treatment options for the intensivist in the acute phase of brain injury. CONCLUSION: Specialised neurointensive care units provide the best environment for the patient with acute brain injury. Outcome is frequently enhanced the clinicians skilled towards dealing with the whole spectrum of neurologic insults.

Expression of the group I metabotropic glutamate receptor in the hippocampus of patients with mesial temporal lobe epilepsy.

Immunocytochemical studies at light and electron microscopic levels in hippocampi of patients with mesial temporal lobe epilepsy showed mGluR1 and mGluR5 immunoreactivity in the molecular layer of the dentate gyrus and CA1 area, especially at the border between stratum oriens and alveus. By electron microscopy, degenerating neuronal elements were found in all areas studied. There were glial filamentous tangles which appeared similar to intranuclear inclusions in astrocytes in all areas studied. Reactive product for mGluR1 was localised only in post-synaptic elements. However, mGluR5 immunoreactivity was demonstrated in both post- and pre-synaptic elements in the molecular layer of the dentate gyrus and CA1 area. Reactive product for mGluR5 was also demonstrated in astrocytes and in the periphery of fibrillary tangles. We postulate that in patients with mesial temporal lobe epilepsy, mGluR1 may increase hippocampal excitability through postsynaptic activation, and mGluR5 may do so through both pre- and post-synaptic mechanisms.

Stereotactic brain biopsies in AIDS patients--early local experience.

AIM: To assess the usefulness of stereotactic brain biopsies in AIDS patients with cerebral lesions in Singapore. METHODS: A total of 10 patients with AIDS and cerebral lesions underwent stereotactic brain biopsies in the Department of Neurosurgery, Tan Tock Seng Hospital (TTSH) between September 1997 and September 1998. The patients were referred from the Communicable Diseases Centre (CDC), TTSH. These patients either failed a trial of therapy for toxoplasmosis encephalitis (TE) or had CT/MRI scans which did not suggest TE. Four were CT-guided and six were MRI-guided stereotactic biopsies. The Radionics Cosman-Robert-Wells (CRW) stereotactic apparatus was used for all cases. RESULTS: The male to female ratio was 9:1. Histological diagnosis from biopsy was lymphoma (5), metastatic adenocarcinoma (1), TE (1), abscess (1), encephalitis (1) and granulomatous tissue (1-presumed tuberculosis). CONCLUSION: The early experience is that stereotactic brain biopsy is useful in patients with AIDS and cerebral lesions. The etiology is confirmed in the majority of cases and impacts on management decisions and prognostication.

Petrosal approach for a large right posterior cerebral artery (P2) aneurysm.

A seven year old girl presented with recurrent headaches Computed tomography (CT) magnetic resonance imaging (MRI) and angiography showed a 2 cm aneurysm at the P2 segment of the right posterior cerebral artery. The aneurysm was trapped successfully by a petrosal approach. The patient made an excellent recovery except for a transient fourth nerve palsy.

Nerve growth factor (NGF) loop 4 dimeric mimetics activate ERK and AKT and promote NGF-like neurotrophic effects.

Previous work indicating that nerve growth factor (NGF) protein loops 2 and 4 interact with TrkA receptors raise the possibility that small molecule mimetics corresponding to TrkA-interacting domains that have NGF agonist activity can be developed. We applied our previously developed strategy of dimeric peptidomimetics to address the hypothesis that loop 4 small molecule dimeric mimetics would activate TrkA-related signal transduction and mimic NGF neurotrophic effects in a structure-specific manner. A loop 4 cyclized peptide dimer demonstrated NGF-like neurotrophic activity, whereas peptides with scrambled sequence, added or substituted residues, or cyclized in monomeric form were inactive. Activity was blocked by the TrkA inhibitors K252a and AG879 but not by NGF p75 receptor blocking antibody. Dimeric, but not monomeric, peptides partially blocked NGF activity. This profile was consistent with that of a NGF partial agonist. ERK and AKT phosphorylation was stimulated only by biologically active peptides and was blocked by K252a. The ERK inhibitor U0126 blocked the neurite- but not the survival-promoting activity of both NGF and active peptide. These studies support the proof of concept that small molecule NGF loop 4 mimetics can activate NGF signaling pathways and can mimic death-preventing and neurite-promoting effects of NGF. This finding will guide the rational design of NGF single-domain mimetics and contribute to elucidating NGF signal transduction mechanisms.

Tension pneumocephalus and pneumorachis secondary to subarachnoid pleural fistula.

A case of tension pneumocephalus and pneumorachis secondary to a subarachnoid pleural fistula after thoracic spinal surgery is described. This rare complication was diagnosed on CT. The imaging findings, significance and management of this unusual condition are discussed.

Computer-aided stereotactic functional neurosurgery enhanced by the use of the multiple brain atlas database.

This paper introduces a computer-aided atlas-based functional neurosurgery methodology and describes NeuroPlanner, a software system which supports it. NeuroPlanner provides four groups of functions: 1) data-related for data reading, interpolation, reformatting, and image processing; 2) atlas-related for multiple atlases reading, atlas-to-data global and local registrations, two-way anatomical indexing, and multiple labeling in two and three dimensions; 3) atlas-data exploration-related for three-dimensional (3-D) display and real-time manipulation of cerebral structures, continuous navigation, two-dimensional (2-D), triplanar, 3-D presentations, and 2-D interaction in four views; and 4) neurosurgery-related for targeting, trajectory planning, mensuration, simulating the insertion of microelectrode, and simulating therapeutic lesioning. All operations, excluding atlas and data reading, are real time. The combined anatomical index of the multiple brain atlas database containing complementary 2-D and 3-D atlases has about 1000 structures per hemisphere, and over 400 sulcal patterns. Neurosurgical planning with mutually preregistered multiple brain atlases in all three orthogonal orientations is novel. The approach is validated with 24 intraoperative and postoperative datasets for thalamotomies, thalamic stimulations, pallidotomies, and pallidal stimulations. Its potential benefits include increased accuracy of target definition, reduced time of the surgical procedure by decreasing the number of tracts, facilitated planning of more sophisticated trajectories, lowered cost by reducing the number of microelectrodes used, reduced surgical complications, and the extra degree of confidence given to the neurosurgeon.