Subarachnoid Haemorrhage Incidence Pattern Analysis with Circular Statistics.

Knowledge about biological rhythms of diseases may not only help in understanding the pathophysiology of diseases but can also help health service policy makers and emergency department directors to allocate resources efficiently. Aneurysmal subarachnoid haemorrhage (SAH) has high rates of morbidity and mortality. The incidence of SAH has been attributed to patient-related factors such as characteristics of aneurysms, smoking, and hypertension. There are studies showing that the incidence of aneurysmal SAH appears to behave in periodic fashions over long time periods. However, there are inconsistencies in the literature regarding the impact of chronobiological factors such as circadian, seasonal, and lunar cycle factors on the occurrence of SAH. In this study, we focused on the analysis of a temporal pattern of SAH (infradian rhythms) with a novel approach using circular statistical methods. We aimed to see whether there is a circular pattern for the occurrence of SAH at all and if so, whether it can be related to known temporal patterns based on available literature. Our study did not support the notion that aneurysmal subarachnoid haemorrhages occur on any specific day in a cycle with specific lengths up to 365 days including specific weekdays, full moon, equinoxes, and solstices. Hence, we found no relationship between SAH incidence and timing. Study in larger populations using similar circular statistical methods is suggested.

Intramedullary spinal cord metastases: a 20-year institutional experience with a comprehensive literature review.

OBJECTIVES: To review previous reports as well as our institutional experience to address the issues regarding patient management and also to assess the predisposing factors that might influence outcome and survival. METHODS: We undertook a 20-year (1989-2009) retrospective study of a series of eight patients diagnosed with intramedullary spinal cord metastases (ISCMs) in our institute. We further reviewed 293 cases of ISCMs reported in the English literature since 1960. Characteristics regarding the site of the primary cancer, location of ISCM, the presence of other metastases, presenting neurological symptoms/signs, duration of symptoms, and the time interval from diagnosis of the primary tumor to ISCM were pooled. We analyzed the different treatment approaches, the functional outcome, and the factors influencing survival. RESULTS: Lung and breast cancers appear to be the most frequent source of ISCM with cervical, thoracic, and lumbar spine being equally affected. Motor weakness predominates as the commonest symptom at presentation, followed by pain and sensory disturbance. At diagnosis, most patients with ISCM have a known primary cancer often associated with cerebral and other systemic metastases. Overall survival of ISCM is poor (median: 4 months from the time of diagnosis). Survival in surgical patients is 6 months, compared with 5 months in those conservatively managed. Clinical improvement was observed in more than one-half of those treated surgically, whereas neurological status was maintained in most patients treated conservatively. CONCLUSION: ISCM is an unusual site for metastasis. Regardless of the treatment, its prognosis is generally poor as its presence often signifies end-stage cancer. However, with early diagnosis and appropriate treatment, selected patients may benefit from improved neurological outcome and quality of life.

Radiation-induced moyamoya disease after childhood astrocytoma.

Adjunctive radiation treatment of childhood intracranial neoplasms of grade II or higher creates a risk of subsequent vasculopathy. A 28-year-old male presented with a Glasgow Coma Scale 12 after acute collapse and hemiparesis with an intraparenchymal haematoma. Emergent craniotomy, histopathology and subsequent imaging confirmed the cause as radiation-induced moyamoya disease, subsequent to treatment for a grade 2 astrocytoma 24 years previously. He had been lost to follow-up after normal serial imaging performed up to 10 years after his initial diagnosis. Long term surveillance imaging may be of benefit in identifying treatable vascular anomalies.

Complications of posterior cranial fossa surgery--an institutional experience of 500 patients.

BACKGROUND: The complication of the posterior fossa surgery is seldom described in the literature. The purposes of this retrospective study are to draw attention to the potential complications associated with posterior fossa surgery and to critically review the predisposing factors that might influence the complication rate. METHODS: We undertook a 10-year (1992-2002) retrospective study of all posterior fossa surgery performed at LSUHSC. A total of 500 patients were obtained from the operation database, and they were categorized into 5 groups based on the surgical approaches: (1) cerebellopontine angle lesion, (2) microvascular decompression for facial pain and spasm, (3) cerebellar lesions, (4) Chiari I decompression, and (5) petroclival lesions. Data collected for analysis included patient demographics, pathological characteristics of the lesions, and the postoperative complications that occurred as unexpected and undesirable events that prolonged hospital stay and may require surgical/medical intervention. RESULTS: Of the 500 patients reviewed, 220 (44%) patients had tumor resections at the cerebellopontine angle; 110 (22%) patients had microvascular decompression for trigeminal neuralgia and hemifacial spasm; 86 (17.2%) patients had cerebellar lesions; 60 (12%) patients had Chiari I decompression; and 24 (4.8%) patients required transpetrosal approaches for petroclival lesions. The overall complication rate in our study was 31.8%, affecting 159 patients. Cerebrospinal fluid leaks were the most frequently encountered, presenting in 65 (13%) patients followed by meningitis in 46 (9.2%) patients, wound infection in 35 (7%) patients, and CN palsies in 24 (4.8%) patients. Other complications that were observed to develop almost exclusively in patients undergoing cerebellar parenchymal tumor resection included cerebellar edema in 25 (5%) patients, hydrocephalus in 23 (4.6%) patients, cerebellar hematoma in 15 (3%) patients, and cerebellar mutism in 6 (1.2%) patients. The overall mortality rate related to surgery was 2.6% occurring in 13 patients. CONCLUSION: Posterior fossa surgery involves greater morbidity and mortality and has a wider variety of complications than surgery in the supratentorial compartment. These complications may be avoided by careful perioperative planning, strict adherence to aseptic technique, meticulous microsurgical dissection, proper wound closure, and the judicious use of prophylactic agent. A thorough understanding of the patient's history, neurological findings, imaging studies, operative anatomy, as well as all potential adverse events associated with the procedure is also essential to minimize complications.

Spontaneous regression of syringomyelia--review of the current aetiological theories and implications for surgery.

A number of hypotheses have been postulated to explain the development of syringomyelia associated with Chiari I malformation. However, the mechanism of syrinx development is still poorly understood. Furthermore, the outcomes of current surgical procedures have been variable. There is evidence that the syringomyelia can spontaneously resolve, and this may warrant a more conservative approach to monitor the progression of neurological deficits. In this paper, we present a patient with spontaneous regression of syringomyelia. The current aetiological theories are discussed.

Traumatic intracranial aneurysm: a brief review.

Traumatic intracranial aneurysms are uncommon and represent fewer than 1% of all cerebral aneurysms. They may develop after blunt or penetrating head injuries and can present both diagnostic challenges and surgical difficulties. Because traumatic aneurysms are fragile and prone to rupture, early diagnosis with cerebral angiography and prompt treatment are essential. We present two patients with traumatic aneurysms and discuss their aetiology, classification, clinical presentations, diagnosis, and treatment options.

Solitary choroid plexus metastasis from carcinoma of the oesophagus.

Metastatic tumors to the brain presenting exclusively in the choroid plexus are rare and are most frequently associated with renal cell carcinoma. In this paper, the authors report an unusual case of intraventricular metastasis, and to the authors' knowledge, this is the first case of solitary metastasis from oesophageal carcinoma to the choroid plexus to be described in the literature. Metastatic disease is an important differential diagnosis which must be considered even for a patient without a documented primary malignancy who presents with a single lesion in the ventricle.