Chiari malformation in nonsyndromal single craniosynostosis--much ado about nothing?

BACKGROUND: The significance of Chiari malformation in nonsyndromal-isolated craniosynostosis is still not well documented. Hence, in the present study we investigated the incidence of Chiari malformation in a larger series of patients with nonsyndromic-isolated single-suture craniosynostosis over a 9-year period using preoperative magnetic resonance imaging (MRI). METHODS: Of 215 children who had undergone surgery for nonsyndromic-isolated craniosynostosis, 89 cases (41.4 %) had MRI prior to surgery. All MRIs were screened for Chiari malformation. RESULTS: Only one patient (1.1 %) with isolated lambdoid synostosis showed Chiari malformation preoperatively, which was defined as a cerebellar tonsillar descent greater than 5 mm below the foramen magnum. However, no clinical symptoms were associated with Chiari malformation in this patient. CONCLUSIONS: As Chiari malformation is more likely to be associated with syndromic craniosynostosis, nonsyndromic bilateral coronal synostosis, or synostosis of the lambdoid suture, a general use of MRI as a screening tool for Chiari malformation should not be recommended for patients with nonsyndromic-isolated craniosynostosis who lack clinical symptoms.

Cerebral microdialysis in acutely brain-injured patients with spreading depolarizations.

Multimodal cerebral monitoring was utilized to examine the relationship between pathological changes in microdialysis parameters and the occurrence of spreading depolarizations (SD) in brain-injured patients. SD are a relatively newly discovered phenomenon in man found to be linked to secondary insults and infarct growth and they can be detected via electrocorticography (ECoG). A total of 24 brain-injured patients (mean age: 52±11 years) requiring craniotomy took part in this prospective observational study. Each patient was monitored with a linear strip electrode for ECoG data and a cerebral microdialysis probe. SD were detected in 13 of the 24 patients. Pathological concentrations of glucose and lactate in brain parenchyma were significantly correlated with various time points prior to and/or immediately following the SD. Severe systemic hyperglycemia and systemic hypoglycemia were also found to be correlated with the occurrence of SD. The present study shows a clear relationship between SD and pathological changes in cerebral metabolism; further studies are needed to elucidate these complex interactions with the ultimate goal of developing therapeutic strategies for improving outcome in brain-injured patients.

[Intensive care management [corrected] of patients with intracerebral hemorrhage]. / Intensivmedizinische Versorgung von Patienten mit intrazerebraler Blutung.

Approximately 10-15% of acute strokes are caused by non-aneurysmatic intracerebral hemorrhage (ICH) and incidences are expected to increase due to an aging population. Studies from the 1990s estimated mortality of ICH to be as high as 50%. However, these figures may partly be attributed to the fact that patients suffering from ICH frequently received only supportive therapy and the poor prognosis may therefore be more a self-fulfilling prophecy. Recently it has been shown that treatment in a specialized neurological intensive care unit alone was associated with better outcomes after ICH. In recent years considerable efforts have been undertaken in order to develop new therapies for ICH and to assess them in randomized controlled trials. Apart from admission status, hemorrhage volume is considered to be the main prognostic factor and impeding the spread of the hematoma is thus a basic therapeutic principle. The use of activated factor VIIa (aFVIIa) to stop hematoma enlargement has been assessed in two large randomized controlled trials, however the promising results of the dose-finding study could not be confirmed in a phase III trial. Although hemostatic therapy with aFVIIa reduced growth of the hematoma it failed to improve clinical outcome. Similar results were found in a randomized controlled trial on blood pressure management in acute ICH. The link between reduction of hematoma growth and improved outcome is therefore still lacking. Likewise the value of surgical hematoma evacuation remains uncertain. In the largest randomized controlled trial on surgical treatment in ICH so far, only a small subgroup of patients with superficial hemorrhages seemed to benefit from hematoma evacuation. Whether improved intensive care can contribute to improved outcome after ICH will be shown by data obtained in the coming years.

Serial diffusion and perfusion MRI analysis of the perihemorrhagic zone in a rat ICH model.

OBJECTIVES: Cerebral ischemia has been proposed as a contributing mechanism to secondary neuronal injury after intracranial hemorrhage (ICH). We aimed to examine perihemorrhagic changes with an animal experimental MRI study using a stroke-MRI protocol. In a subset of animals the feasibility and effects of stereotactic hematoma evacuation was investigated. METHODS: An MRI compatible setup for rats was established using a double injection model. ICH was stereotactically placed into the right basal ganglia of 49 Wistar rats. Coronal T2-WI, T2*-WI, DWI and PWI were generated with a 2.35T animal MRI scanner at 3 time points. Clot volumes, normalized ADC and relative MTT values were analysed in 3 hematoma regions (periphery, outer rim, healthy ipsilateral tissue) in all sequences. RESULTS: There were no perihemorrhagic ADC decreases consistent with ischemic cytotoxic edema but a mild vasogenic edema surrounding the ICH could be observed. This improved partially with evacuation. Reduced perfusion was seen in the periphery and outer rim. This disappeared with lysis and evacuation of the clot. CONCLUSION: No evidence for the existence of a perihemorrhagic ischemic area was found. But, reversible perfusion reduction in this model indicates that early evacuation may help reducing secondary neuronal changes.

Intracranial dermoid cysts: variations of radiological and clinical features.

BACKGROUND: Intracranial dermoid cysts are uncommon, and their clinical features as well as surgical management differ from patient to patient. Dermoids are generally benign lesions, but may cause spontaneous complications such as meningitis and/or hydrocephalus due to rupture and epileptic seizures depending on their location. Little has been reported about characteristic imaging findings with resulting therapeutic considerations, and only a few reports exist about associated hydrocephalus. Imaging modalities have changed and can facilitate differential diagnosis and follow-up if applied correctly. In this paper, we attempt to contribute our clinical experience with the management of dermoid cysts. PATIENTS AND METHODS: The charts of five men and two women with intracranial dermoid cysts were retrospectively reviewed. The patients were treated between September 1993 and September 2006. Selected patients are presented in detail. RESULTS: Tumour location, size and radiographic characteristics varied in each patient. Clinical presentations comprised focal neurological deficits as well as epileptic seizures, persistent headache, mental changes and psycho-organic syndromes. One patient underwent delayed ventriculo-peritoneal shunting after ruptured fatty particles caused obstructive hydrocephalus. Despite dermoid rupture into the subarachnoid space, three patients never developed hydrocephalus. Diffuse vascular supra-tentorial lesions were seen in one patient as a result of aseptic meningitis. Diffusion-weighted imaging (DWI) hyperintensity in dermoids is related to decrease of water proton diffusion and should be used for both the diagnosis and follow-up of this lesion. CONCLUSION: Although dermoid cysts are known to be benign entities per se, their rupture can cause a wide range of symptoms including aseptic meningitis and/or hydrocephalus. This may be due to intraventricular obstruction and/or paraventricular compression. While rupture does not necessarily bring about hydrocephalus, radical removal of the tumour and close monitoring of ventricular size is required. Although not widely recognised as such, DWI is considered to be a useful imaging modality in the diagnosis and follow-up of dermoids.

An unusual case of a highly progressive supratentorial capillary haemangioblastoma - histopathological considerations.

We describe a case of a rapidly progressive, sporadic, non-von Hippel-Lindau (VHL) disease associated supratentorial capillary haemangioblastoma. Despite the classical histopathological presentation consisting of stromal cells and abundant capillaries, the tumour showed an unfavourable clinical course.

Distal posterior inferior cerebellar artery aneurysms: clinical characteristics and surgical management.

BACKGROUND: Aneurysms located on the distal posterior inferior cerebellar artery (PICA) are rare, and their underlying clinical features and surgical management are poorly understood. We report our series of 16 patients with 18 distal PICA aneurysms. METHOD: All patients with distal PICA aneurysms were treated between March 1996 and August 2004. We excluded all PICA aneurysms that involved the vertebral artery. Patients were analysed in the light of their clinical profiles, radiological studies, intraoperative findings and outcomes. All patients underwent non-enhanced and contrast enhanced CT scans followed by 4-vessel cerebral angiography on admission. The hemorrhagic patterns on initial CT scans were assessed using the Fisher Grading Score. The outcomes were documented using the Glasgow Outcome Scale at time of discharge and at three or twelve months follow-up. FINDINGS: The series included 6 men and 10 women. Massive intraventricular haemorrhage was found in 13 patients with proven CT subarachnoid haemorrhage, one patient revealed SAH without intraventricular components, one presented with only intraventricular blood in the occipital horns and 3 aneurysms were found incidentally without presence of blood. Fourteen aneurysms were saccular and four were fusiform. Nine cases were associated with another cerebrovascular lesion. A lateral transcondylar or a median suboccipital approach was used to secure the aneurysms in 15 patients, either by direct clipping (14 lesions) or vessel sacrifice (3 lesions). One aneurysm was treated by an endovascular approach. At long-term follow up, an excellent or good outcome was achieved in 75% of cases. One patient died due to pre-existing cardiopulmonary complications. CONCLUSIONS: Most of our cases of ruptured distal PICA aneurysms presented with haematocephalus. These were frequently associated with another vascular abnormality and 22% were fusiform or multilobulated. These specific features require special management strategies entailing an appropriate surgical approach to the aneurysm, clipping method, haematoma removal, ventricular drainage and when suitable choice of endovascular interventions.

Stroke magnetic resonance imaging within 6 hours after onset of hyperacute cerebral ischemia.

We studied the diagnostic and prognostic value of diffusion- and perfusion-weighted magnetic resonancce imaging (DWI and PWI) for the initial evaluation and follow-up monitoring of patients with stroke that had ensued less than 6 hours previously. Further, we examined the role of vessel patency or occlusion and subsequent recanalization or persistent occlusion for further clinical and morphological stroke progression so as to define categories of patients and facilitate treatment decisions. Fifty-one patients underwent stroke magnetic resonance imaging (DWI, PWI, magnetic resonance angiography, and T2-weighted imaging) within 3.3 +/- 1.29 hours, and, of those, 41 underwent follow-up magnetic resonance imaging on day 2 and 28 on day 5. In addition, we assessed clinical scores (on the National Institutes of Health Stroke Scale, Scandinavian Stroke Scale, Barthel Index, and Modified Rankin Scale) on days 1, 2, 5, 30, and 90 and performed volumetric analysis of lesion volumes. In all, 25 patients had a proximal, 18 a distal, and 8 no vessel occlusion. Furthermore, 15 of 43 patients exhibited recanalization on day 2. Vessel occlusion was associated with a PWI-DWI mismatch on the initial magnetic resonance imaging, vessel patency with a PWI-DWI match (p < 0.0001). Outcome scores and lesion volumes differed significantly between patients experiencing recanalization and those who did not (all p < 0.0001). Acute DWI and PWI lesion volumes correlated poorly with acute clinical scores and only modestly with outcome scores. We have concluded on the basis of this study that early recanalization saves tissue at risk of ischemic infarction and results in significantly smaller infarcts and a significantly better clinical outcome. Patients with proximal vessel occlusions have a larger amount of tissue at risk, a lower recanalization rate, and a worse outcome. Urgent recanalization seems to be of utmost importance for these patients.