Cerebral venous infarction during a high altitude expedition.

Bilateral venous infarction of the brain due to thrombosis of the deep cerebral venous system is relatively rare, accounting for approximately 3-8 percent of all cases of cerebral venous thrombosis (CVT). Known risk factors include the use of oral contraceptives, pregnancy, puerperium, malignancy and thrombophilic states. CVT, in the setting of acute mountain sickness (AMS), has rarely been reported. We present an unusual occurrence of bilateral deep subcortical venous infarction in a previously-well, 39-year-old woman, who developed AMS during a high altitude expedition in Nepal. The possible mechanisms responsible for this unfortunate event include dehydration with resultant relative polycythaemia and raised intracranial pressure at high altitudes. CVT should be considered in mountain climbers presenting with progressive neurological deterioration that is not solely attributable to AMS.

'Moya' than meets the eye: neurofibromatosis type 1 associated with Moyamoya syndrome.

Moyamoya syndrome (MMS) is an uncommon association of neurofibromatosis type 1 (NF1). We describe a seven-year-old chinese girl with NF1 and unilateral MMS with multiple hyperintensities on T2-weighted magnetic resonance (MR) images. The ischaemic lesions in the ipsilateral white matter were hypointense on fluid attenuated inversion recovery (FLAIR) MR images, in contrast to the hyperintense "unidentified bright objects" (UBOs) of NF1. Neuroradiologists should be aware of associated MMS in NF1 patients, and distinguish the effects of ischaemia from UBOs, especially on FLAIR MR imaging.

Hereditary hemorrhagic telangiectasia in children: endovascular treatment of neurovascular malformations: results in 31 patients.

Hereditary hemorrhagic telangiectasia (HHT) is a heterogeneous disease that can present with a variety of clinical manifestations. The neurovascular complications of this disease, especially in children, may be potentially devastating. The purpose of this article was to review the therapeutic results of endovascular treatment of neurovascular malformations in children. A total of 31 patients under the age of 16 were included in this retrospective analysis. All children were treated in a single center. Twenty children presented with 28 arteriovenous (AV) fistulae, including seven children with spinal AV fistulae and 14 children with cerebral AV fistulae (one child had both a spinal and cerebral fistulae). Eleven children had small nidus-type AV malformations. All embolizations were performed employing superselective glue injection. Follow-up ranged between 3 and 168 months (mean 66 months). A total of 115 feeding vessels were embolized in 81 single sessions, resulting in a mean overall occlusion rate of the malformation of 77.4% (ranging from 30 to 100%). Two of 31 patients (6.5%) died as a direct complication of the embolization procedure; two patients (6.5%) had a persistent new neurological deficit; eight patients (26.7%) were clinically unchanged following the procedure; in 13 patients (41.9%) an amelioration of symptoms but no cure could be achieved; and six patients (19.4%) were completely asymptomatic following the endovascular procedure. In the surviving patients morphological complete occlusion was possible in twelve patients (38.7%); therapy is still not completed in six patients. Since the natural history of neurovascular manifestations of HHT in children is associated with high morbidity and mortality, therapeutic intervention is mandatory. In most instances a morphological target can be identified; therefore, even partial and staged treatment can be performed. Our results demonstrate that in 27/31 patients these targeted interventions resulted in stabilizing the disease, ameliorating the symptoms or even complete resolution. The endovascular approach employing glue as the embolizing agent represents a safe and efficient way to control the neurovascular phenotypes of HHT.

Neurovascular phenotypes in hereditary haemorrhagic telangiectasia patients according to age. Review of 50 consecutive patients aged 1 day-60 years.

Hereditary haemorrhagic telangiectasia (HHT) is inherited as an autosomal dominant trait with varying penetrance and expressivity. Some of the most devastating consequences of this disease result from cerebral vascular malformations that manifest themselves in either arteriovenous fistulae (AVF), small nidus-type arteriovenous malformations (AVM) or micro-AVMs with a nidus less than 1 cm in size. The purpose of this study was to compare the phenotypes of CNS-manifestations of HHT with the age of the patient. The charts and angiographic films of 50 patients diagnosed with HHT according to the Curaçao criteria were retrospectively evaluated concerning age of onset of symptoms, or, if not applicable of first consultation. The files were reviewed for clinical presentation, family and personal history, while the patients' angiograms were analysed with respect to the number of lesions (single and multiple), the location (superficial supratentorial, deep supratentorial, infratentorial, and spinal), and type of lesion (fistulous AVM, nidus-type AVM, and micro-AVM). A total of 75 central nervous system manifestations of HHT were found. Lesions included seven spinal cord AVFs that were all present in the paediatric age group (mean age: 2.2 years), 34 cerebral AV fistulae, all but two affected patients were less than 6 years (mean age 3.0). Sixteen nidus type AVMs (mean age: 23.1 years) and 18 micro-AVMs (mean age: 31.8 years) were found. HHT displays an age-related penetrance of clinical manifestations. Since members of the same family can present with completely different phenotypes of this disease there seems to be no relationship between the type of mutation and the phenotype of the disease. Since there seems to be a continuum of vascular abnormalities (from large fistulous areas to small AVMs and micro-AVMs) associated with HHT, the most likely determinating factor of the HHT phenotype is the timing of the revealing event in relation to the maturity of the vessel. Presumably, the trigger of the quiescent genetical abnormality transforms a "dormant" disease into a morphologically and therefore clinically detectable one by impairing a specific vessel segment at a specific (more or less vulnerable) period of time. The nature of this triggering event is, however, as of yet unclear.

Hereditary haemorrhagic telangiectasia in children. Endovascular treatment of neurovascular malformations. Results in 31 patients.

SUMMARY: Hereditary haemorrhagic telangiectasia (HHT) is a heterogeneous disease that may present with different clinical phenotypes and different clinical expressions. Concerning the neurovascular expressions of this disease, the paediatric age group in particular presents with potentially devastating symptomatic phenotypes. The purpose of this article was to review the therapeutic results of endovascular treatment of neurovascular malformations in children. A total of 31 children under the age of 16 were included in this retrospective analysis. All children were treated in a single centre. Twenty children presented with 28 arteriovenous (AV) fistulae including seven children with spinal AV fistulae and 14 children with cerebral AV fistulae (one child had both a spinal and cerebral fistulae). Eleven children had small nidus type AV malformations. All embolizations were performed in a single centre employing superselective glue injection. Follow-up ranged between three and 168 months (mean: 66 months) A total of 115 feeding vessels were embolized in 81 single sessions resulting in a mean overall occlusion rate of the malformation of 77.4% (ranging from 30 to 100%). Two of 30 patients (6.5%) died as a direct complication of the embolization procedure, two patients (6.5%) had a persistent new neurological deficit, eight patients (26.7%) were clinically unchanged following the procedure. In 11 patients (36.7%) an amelioration of symptoms but no cure could be achieved, six patients (20%) were completely asymptomatic following the endovascular procedure. In the surviving patients morphological complete occlusion was possible in twelve patients (38%), therapy is still not complete in six patients. Since the natural history of neurovascular manifestations of HHT in children is associated with a high morbidity and mortality, therapeutic intervention is mandatory. In most instances a morphological target can be identified, therefore even partial and staged treatment can be performed. Our results demonstrate that in 27/31 patients these targeted interventions resulted in stabilizing the disease, ameliorating the symptoms or even in curing the patient. The endovascular approach employing glue as the embolizing agent represents therefore a safe and efficient way to control the neurovascular phenotypes of HHT.

"Duplicated" or "multiple" cervical internal carotid and vertebral arteries from fenestration, duplication and vasa vasorum to segmental rete.

SUMMARY: The appearance of multiple cervical arteries may be due to a variety of anatomic situations. Arterial fenestrations and duplications have different anatomic origins, with distinct appearances on angiography. They are associated with incomplete segmental development. The vasa vasorum of the internal carotid artery are rarely seen unless enlarged in pathological situations. They represent a peculiar segmental, in-situ, collateral circulation. Retes, on the other hand, correspond to a more complex reconstitution of an early segmental regression. Careful analysis of each of these features is required to choose the best appropriate terminology. The purpose of this paper is to report illustrative cases to enhance the distinctive features of each disposition.

Intracranial dural arteriovenous fistula presenting with tetraparesis due to cervicomedullary junction compression. A case report.

SUMMARY: Cranial dural arteriovenous fistulas (DAVFs) may give rise to myelopathy due to spinal perimedullary venous drainage causing intramedullary venous hypertension. Such cases are uncommon but not rare, with several cases reported in the literature. We report a case of foramen magnum DAVF presenting with symptoms of tetraparesis. The unusual feature was that in this case it was due to compression of the cervicomedullary junction by a large venous pouch rather than the result of spinal perimedullary venous hypertension. Transarterial glue embolization achieved good reduction of flow in the fistula with shrinkage of the venous pouch and corresponding clinical improvement.

Diffusion-weighted MR imaging in intracranial infections.

INTRODUCTION: Diffusion-weighted magnetic resonance (MR) imaging (DWMRI) is valuable in the assessment of acute cerebral infarction and may be useful for other diseases of the central nervous system (CNS). In this study, we present the DWMRI appearance of intracranial infection. MATERIALS AND METHODS: Thirty patients with clinical diagnosis of CNS infection were reviewed. All patients underwent conventional contrast-enhanced MR examination and DWMRI using single-shot echo-planar imaging at b = 1000 s/mm2. RESULTS: Cerebral abscess, tuberculoma, subdural empyema and epidural abscess were hyperintense on DWMRI. Neurocysticercosis showed hypointense lesions on DWMRI. Four of 5 patients with encephalitis showed DWMRI hyperintensity; the appearance of toxoplasmosis lesions was variable. Patients suffering from meningitis without parenchymal involvement did not exhibit any abnormality of diffusion. One patient with tuberculous meningitis developed abnormality on DWMRI from acute cerebral infarction. CONCLUSION: DWMRI increased lesion conspicuity and may be useful in assessment of cerebral infection. There were striking differences in the DWMRI appearances caused by different organisms and diseases.

Intracerebral schwannoma--a rare cause of epilepsy.

INTRODUCTION: We report a case of schwannoma occurring in an intra-axial location causing seizures. CLINICAL PICTURE: A 13-year-old girl presented with a 4-month history of seizures. Preoperative computed tomography scan and magnetic resonance imaging revealed an enhancing right frontal lobe tumour with surrounding oedema. TREATMENT: The patient underwent craniotomy and a well-circumscribed tumour was completely resected. Histology with immunohistochemistry confirmed the diagnosis of an intracerebral schwannoma. OUTCOME: The patient made a complete recovery and was seizure-free at 1-year follow-up. CONCLUSION: Intracerebral schwannomas are rare, benign tumours. They may mimic astrocytomas or malignant tumours, and it is important to differentiate them from other neoplasms with less favourable outcomes. The neuroimaging features are, however, non-specific and definitive diagnosis can only be made on histology.

Limited magnetic resonance imaging (MRI) and the occult hip fracture.

INTRODUCTION: Diagnosis of hip fracture is normally readily made from clinical evaluation and plain radiographs. Occasionally, clinical suspicion of fracture is not confirmed on plain X-rays. MATERIALS AND METHOD: Between January 2001 and March 2002, 422 patients were admitted to our department for post-traumatic hip pain. The diagnosis of hip fracture was unequivocally made in 365 patients (86%). Fifty-seven (14%) patients had a negative or equivocal radiograph. RESULTS: Limited magnetic resonance imaging (MRI) of the hip in this group of 57 patients confirmed that 8 (14%) sustained a femoral neck fracture, while 5 (9%) had an intertrochanteric fracture. In 19 patients (33%), some other pathology was found, mainly stable fractures of the femoral trochanters and pubic rami. Overall, 32 scans (56%) were positive and 25 (44%) were negative. Limited MRI detected patients with undisplaced hip fractures and identified them as candidates for surgery. CONCLUSION: The use of MRI in this specific and 'limited' way provides orthopaedic surgeons with a rapid, accurate and cost-effective diagnostic tool in this clinical scenario. Definitive diagnosis allows the correct management plan to be implemented early. We recommend that patients, who have significant hip pain following injury but indeterminate plain radiographs, undergo a limited MRI scan as a matter of routine.

The acute presentation of pulmonary thromboembolism: a retrospective viewpoint.

INTRODUCTION: Acute pulmonary thromboembolism (PE) has been considered rare among Asians. We aim to describe the frequency and clinical features of this condition in a hospital in Singapore. Among patients admitted by the Emergency Department (ED), comparisons were made between those primarily diagnosed in the ED and those who were not. MATERIALS AND METHODS: Retrospective review of all cases of radiologically proven acute PE over a 20-month period. RESULTS: Sixty-two patients were identified. The mean age was 61.5 +/- 18.0 years with a female to male ratio of 1.8:1. There were more Malays compared to other races. There were also more Caucasians, given the proximity of the hospital to the airport and the inclusion of tourists. The commonest symptoms were dyspnoea and chest pain, while the commonest signs were tachycardia and tachypnoea. Prolonged immobilisation was the commonest risk factor. Electrocardiographic S1Q3T3 pattern was seen in more patients compared to Western studies. Cardiomegaly was the commonest chest X-ray finding. Thirty-two patients were identified to have a source of embolisation. Overall mortality rate was 21%. The ED diagnosed 36% of the cases. Alternative admitting diagnoses were predominantly ischaemic heart disease and pneumonia. The group diagnosed in the ED were notably female (P = 0.044), Caucasian (P = 0.002) and had prolonged immobilisation (P = 0.025) prior to the onset of PE. CONCLUSION: Acute PE is not as rare here as previously thought. Clinical features reveal more similarities than differences compared to other studies in the literature. We advocate a high index of suspicion for earlier diagnosis in the ED.

Adrenal myelolipoma presenting with spontaneous retroperitoneal haemorrhage demonstrated on computed tomography and angiogram--a case report.

INTRODUCTION: A rare case of adrenal myelolipoma presenting with spontaneous rupture and retroperitoneal haemorrhage is described. CLINICAL PICTURE: A 51-year-old Caucasian male presented with acute onset of right loin pain. Preliminary diagnosis of haemorrhagic adrenal tumour was made on computed tomography (CT) and angiography. TREATMENT: Vascular embolisation was performed to stabilise the patient prior to definitive surgery. Tumour resection was subsequently performed. Histology confirmed ruptured adrenal myelolipoma. OUTCOME: The patient made an uneventful recovery. CONCLUSION: Ruptured adrenal myelolipoma should be considered in cases of spontaneous retroperitoneal haemorrhage. Vascular embolisation may be useful in stabilising the patient prior to definitive surgery.

To establish the normal bone mineral density reference database for the Singapore male.

INTRODUCTION: The objective of this study was to establish the normal bone mineral density (BMD) reference curve for the Asian Singapore male. MATERIALS AND METHODS: Three hundred and eighty-three male subjects were enrolled; comprising of 309 Chinese, 44 Malays and 30 Indians resident in Singapore. Bone mineral density was measured at the lumbar spine and left hip using a Hologic QDR 4500 Elite dual-energy X-ray absorptiometry (DXA) scanner. RESULTS: The mean peak BMD for the average lumbar spine and the neck of femur was 1.006 g/cm2 and 0.97 g/cm2, respectively. The mean peak BMD was taken at the 20 to 24 years age group at both the hip and spine based on data distribution for the various age groups. The BMD corresponding to -2.5 standard deviations from the peak adult value was 0.719 g/cm2 for the average lumbar spine and 0.655 g/cm2 for the neck of femur. CONCLUSION: This Asian male BMD reference database, which is 10% and 5% lower than corresponding values from the Caucasian reference database, allows for more accurate diagnosis of osteoporosis in Asian males.