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Biomedical subjects

Knut Wester

Publications and source records attributed to Knut Wester.

18 recordsLinked to original sources
PubMed2006

Intracystic pressure in patients with temporal arachnoid cysts: a prospective study of preoperative complaints and postoperative outcome.

BACKGROUND: Arachnoid cysts (AC) can cause a wide spectrum of clinical symptoms. Only a limited number of studies have investigated intracranial pressure in patients with AC. We wished to investigate the relationship between intracystic pressure, preoperative complaints and postoperative symptom relief in adult patients operated on for a unilateral temporal AC. MATERIAL AND METHODS: This was a prospective, population based study involving 38 adult (>18 years) patients (mean age 43 years; range 18-69) with a previously untreated unilateral temporal AC. RESULTS: For all cyst types, mean pressure was 131 mm H2O. The main preoperative complaints were headache and dizziness/nausea. By median split, patients were divided into a low pressure (<130 mm H2O) and a high pressure (>130 mm H2O) group. Patients with high intracystic pressure had a significantly higher preoperative visual analogue scale (VAS) score (54.7) than that found in patients with low intracystic pressure (39.4). Both pressure groups had a significant fall in VAS score after surgical decompression of the cyst. Intracystic pressure correlated significantly with arterial pCO2 and mean arterial pressure. CONCLUSION: There was a significant correlation between intracystic pressure and the preoperative level of complaints. Mean intracystic pressure in adult patients with unilateral temporal AC seems to lie within the limits of normal intracranial pressure. We therefore hypothesise that factors other than absolute pressure, such as altered compliance and impedance of the brain, may be involved in the pathophysiology of intracranial AC.

Adolescent↗
PubMed2006

[Impact of Scandinavian guidelines on management of mild head injuries].

BACKGROUND: A national survey in 1996 showed insufficient routines for management of patients with mild head injuries in Norwegian hospitals. Since then, the Scandinavian guidelines for management of mild head injuries have been published. METHODS: A cross-sectional questionnaire survey of management practice was performed in all 59 hospitals in 2002. We compared the results with figures from 1996 and evaluated guideline compliance. RESULTS: The proportion of noncompliant hospitals was reduced (p = 0.02) from 52% to 31%. The proportion assessing patient consciousness according to the Glasgow Coma Scale increased (p = 0.001) from 49% to 80%. The proportion requiring a normal computed tomographic scan if a patient with a history of loss of consciousness was to be discharged from the emergency department increased (p < 0.001) from 2% to 19%. CONCLUSION: The Scandinavian guidelines have had a significant impact on management practice in Norwegian hospitals.

Craniocerebral Trauma↗
PubMed2006

Arachnoid cysts in adults: long-term follow-up of patients treated with internal shunts to the subdural compartment.

BACKGROUND: We have previously presented an alternative method for surgical decompression of intracranial arachnoid cysts. This minimally invasive method, with insertion of an internal shunt from the cyst to the subdural compartment, seemed to be an efficient and simple, and hence promising technique. The aim of the present study was to investigate the long-term results of this procedure. METHODS: This study is a questionnaire-based retrospective study that includes 31 adult patients (>18 years) who were operated on in our department for an arachnoid cyst in the temporal fossa or overlying the frontal convexity with the internal shunt technique between April 1990 and October 2003. Follow-up ranged from 15 months to 14.8 years (mean = 8.2 years). RESULTS: Of the patients, 83% were asymptomatic or had insignificant complaints at follow-up. A total of 17% reported no reduction of the preoperative complaints. No patient experienced worsening of the symptoms. The cyst was no longer visible on postoperative radiologic examinations in 37% of the patients. In 37%, the postoperative fluid volume was less than 50% of the original volume. In 13%, the cyst volume was reduced but the postoperative volume was greater than 50% of the original cyst volume. Thus, the cyst was unchanged in only 13% of the patients. There was no correlation between volume reduction and clinical improvement. A complication (subdural hygroma or hematoma) occurred in 7 patients, all with temporal cysts, leading to reoperation in 4. None of the complications caused permanent neurologic deficits or invalidity. Seven patients were reoperated on because of suspected or established treatment failure. CONCLUSIONS: The internal shunt technique is a relatively simple, safe, and efficient alternative method for treatment of arachnoid cysts. It should be considered a valuable alternative in the treatment of arachnoid cysts.

Adult↗
PubMed2005

[Brain metastases in adults].

BACKGROUND AND METHODS: Brain metastases are far more common than primary central nervous system tumours. Based on our own clinical experiences and relevant literature published over the last decade (Medline), we present an overview of diagnosis and treatment. RESULTS: Brain metastases are caused by haematogenous spread from extracranial tumours, most frequently from cancers in the lung, breast, melanoma, renal carcinomas and colorectal carcinomas. Three out of four patients present with multiple brain metastases. Cerebral MR is the most sensitive investigation. The most important prognostic factors for survival are Karnofsky score, age < 65, well controlled primary cancer and absence of systemic cancer disease. INTERPRETATION: Some patients are offered neurosurgical treatment (surgery or gamma knife), depending on their clinical status, the number and location of brain metastases, and the histology and degree of systemic involvement of the primary tumour. The gamma knife is the treatment of choice with multiple and solitary tumours smaller than 3 cm that lie deep within the brain or within eloquent areas, whereas surgery is the treatment of choice with solitary metastases larger than 3-3.5 cm that are surgically accessible and cause significant mass effects. Solitary lesions without significant mass effect can be treated with either technique, as their documented efficacies are similar. However, the gamma knife is often preferred since this method is rapid, less invasive, has low morbidity and shortens the hospital stay.

Adult↗
PubMed2005

[Deaths from traumatic brain injury in the Nordic countries, 1987-2000].

BACKGROUND: Traumatic brain injury (TBI) is the major cause of death among young adults in western countries. In the context of a joint Nordic initiative regarding future management of patients with severe TBI, it was of interest to look into the magnitude of the problem and the most recent developments. MATERIAL AND METHODS: We have conducted a survey of the epidemiological aspects of TBI deaths in Denmark, Finland, Norway and Sweden for the period 1987-2000. Data were retrieved from the official statistical agencies in the four countries. We have also collected data on the number of operations for acute TBI in the year 2000 from all Nordic hospitals admitting trauma patients. RESULTS: There were almost twice as many deaths from TBI in Finland as in the other Nordic countries. The median mortality rate in Finland was 21.2 per 100,000 per year. The corresponding figures for Denmark were 12.8, Norway 10.5 and Sweden 9.8. Finland also had almost twice as many operations for acute TBI with 10.0 per 100,000 per year, versus 5.1 in Denmark, 4.8 in Norway and 5.7 in Sweden. The mortality rate was about three times higher among males than among females. All countries except Finland had a significant reduction in TBI deaths during the study period. The mortality rate from injuries other than TBI was more or less the same in all four countries. INTERPRETATION: Our findings imply that there are twice as many severe TBIs and related deaths in Finland compared with the other Nordic countries.

Adult↗
PubMed2005

Arachnoid cysts cause cognitive deficits that improve after surgery.

The authors investigated cognition in patients with arachnoid cysts by assessing 55 patients and 32 control subjects on four different cognitive tests preoperatively and 3 months postoperatively. The patients improved their performance from preoperative to postoperative testing, whereas the control subjects did not show a similar improvement.

Adolescent↗
PubMed2005

Head position and impact direction in whiplash injuries: associations with MRI-verified lesions of ligaments and membranes in the upper cervical spine.

In the present study, we compared magnetic resonance imaging (MRI) findings of soft tissue structures in the upper cervical spine between whiplash-associated disorder (WAD) patients and population-based control persons, and examined whether MRI-verified abnormalities in WAD patients were related to accident-related factors hypothesized to be of importance for severity of injury. A total of 92 whiplash patients and 30 control persons, randomly drawn, were included. Information on the accident-related factors (i.e., head position and impact direction) was obtained by a questionnaire that was answered within 1 week after the accident. The MRI examination was performed 2-9 (mean 6) years after the accident. Focus was on MRI abnormalities of the alar and the transverse ligaments, and the tectorial and posterior atlanto-occipital membranes, graded 0-3. For all neck structures, the whiplash patients had more high-grade lesions (grade 2 or 3) than the control persons (Chi-square test, p < 0.055). An abnormal alar ligament was most common (66.3% graded 2 or 3). Whiplash patients who had been sitting with their head/neck turned to one side at the moment of collision more often had high-grade lesions of the alar and transverse ligaments (p < 0.001, p = 0.040, respectively). Severe injuries to the transverse ligament and the posterior atlanto-occipital membrane were more common in front than in rear end collisions (p < 0.001, p = 0.001, respectively). In conclusion, the difference in MRI-verified lesions between WAD patients and control persons, and in particular the association with head position and impact direction at time of accident, indicate that these lesions are caused by the whiplash trauma.

Accidents, Traffic↗
PubMed2005

Whiplash-associated disorders impairment rating: neck disability index score according to severity of MRI findings of ligaments and membranes in the upper cervical spine.

The aim of this study was to explore whether reported pain and functional disability in whiplash-associated disorders (WAD) patients is associated with lesions to specific soft tissue structures in the upper cervical spine, as assessed by MRI. Pre-selected structures for MRI assessment included the alar ligaments, the transverse ligament, the tectorial and the posterior atlanto-occipital membranes. The questionnaire employed was a modification of the Oswestry Low Back Pain Index. It was comprised of ten single items related to pain and activity of daily living. Ninety-two whiplash patients and 30 control persons, randomly drawn, were included. WAD patients reported significantly more pain and functional disability than the controls, both for total score and each of the ten single items. In the WAD patients, MRI lesions to the alar ligaments showed the most consistent association to the reported pain and disability. Lesions to other structures often occurred in combination with lesions to the alar ligaments. Lesions to the transverse ligament and to the posterior atlanto-occipital membrane also appeared to be related to the NDI score, although the association was weaker than for the alar ligament. The disability score increased with increasing number of abnormal (grade 2-3) structures. These results indicate that symptoms and complaints among WAD patients can be linked with structural abnormalities in ligaments and membranes in the upper cervical spine, in particular the alar ligaments.

Activities of Daily Living↗
PubMed2004

Pigmented astrocytoma with suprasellar location: case report and literature review.

A large suprasellar, partly cystic, contrast-enhancing tumor was resected from a 19-year-old woman who presented with bitemporal visual field defects and reduced visual acuity. Grossly, the tumor was brown and located in the subarachnoid space. Histologically, it was composed of spindle and pleomorphic cells, including giant tumor cells, with markedly pleomorphic nuclei. Reticulin fibers surrounded single cells and small groups of cells. Very few mitotic figures were found in the tumor, and no necrosis or microvascular proliferation was seen. The tumor thereby resembled a pleomorphic xanthoastrocytoma. Many of the tumor cells contained a dark-brown intracytoplasmic pigment, shown to be melanosomal melanin by ultrastructural examination. Immunohistochemical examination demonstrated that the pigment was present in glial tumor cells. Only four cases of pigmented astrocytic tumors have been published, none of these were suprasellar. Our patient received fractionated radiotherapy with a total dose of 48.6 Gy 14 months after gross total removal of the tumor. She is alive without relapse after 12-year follow-up.

Adolescent↗
PubMed2003

Verbal laterality and handedness in patients with intracranial arachnoid cysts.

Left-handedness is most often genetic, but may also follow early, localised damage to the developing brain. This so-called "pathological" left-handedness syndrome is often associated with right hemisphere speech dominance. To find out whether verbal laterality or handedness were affected by congenital, intracranial arachnoid cysts, 51 consecutive patients with temporal or frontal arachnoid cysts were tested for handedness and verbal laterality, as measured with the dichotic listening (DL) technique. Handedness was normal in all subgroups of patients. In the preoperative DL test, only 51 % of the patients showed the normal superiority of the right ear (Right Ear Advantage - REA), significantly different from the REA frequency (74 %) in a normal reference group. Patients with a left temporal, or a frontal cyst had significantly lower preoperative REA frequencies than the reference group, whereas patients with a right temporal cyst did not differ from the reference group. Three to six months after decompressive surgery, the REA frequency (73 %) in the cyst patients was no longer different from that of the reference group. This postoperative normalization was seen both in patients with a left temporal or a frontal cyst. It is concluded that arachnoid cysts may suppress cognitive, cortical functions, and that this suppression can be reversed by surgical decompression of the cyst, even in adults. In our opinion, this cognitive "normalization" may in itself be an indication for decompressive surgery. It is further concluded that, although such cysts are congenital, the pressure from the cyst on the adjacent brain is not strong, nor persistent enough to cause a pathological left-handedness.

Arachnoid Cysts↗
PubMed2003

Mild head injuries: impact of a national strategy for implementation of management guidelines.

BACKGROUND: A national survey in 1996 showed insufficient routines for management of patients with mild head injuries in Norwegian hospitals. Since then, the Scandinavian Guidelines for Management of Mild Head Injuries have been published. METHODS: A cross-sectional questionnaire survey of management practice was performed in all 59 hospitals in 2002. We compared the results with figures from 1996 and evaluated guideline compliance. RESULTS: The proportion of noncompliant hospitals was reduced (p = 0.02) from 52% to 31%. The proportion assessing the patient's level of consciousness according to the Glasgow Coma Scale increased (p = 0.001) from 49% to 80%. The proportion requiring a normal computed tomographic scan if a patient with a history of loss of consciousness was to be sent home from the accident and emergency department increased (p < 0.001) from 1 (2%) to 13 (19%). CONCLUSION: The Scandinavian Guidelines for Management of Mild Head Injuries have had a significant impact on management practice in Norwegian hospitals.

Algorithms↗
PubMed2003

Cerebral atypical teratoid/rhabdoid tumor of infancy: long-term survival after multimodal treatment, also including triple intrathecal chemotherapy and gamma knife radiosurgery--case report.

Cerebral atypical teratoid/rhabdoid tumors (AT/RT) of infancy are highly malignant and have a poor prognosis. The authors report on one case with long-term survival. The patient was a 1 year-old boy presenting with a large AT/RT in the right temporal lobe. He was treated with complete surgery, followed by multiagent chemotherapy. Later he had a second resection and intrathecal chemotherapy and Gamma knife radiosurgery was added to the treatment. Except for a well-controlled temporal epilepsy, the boy is doing well after 6 years follow-up. AT/RT should be treated in a multimodal way. Intrathecal chemotherapy and Gamma knife radiosurgery of single recurrent or residual tumors might increase survival.

Antineoplastic Agents↗
PubMed2002

[Stereotactic radiosurgery of cerebral arteriovenous malformations].

BACKGROUND: Different treatment modalities are being used for cerebral arteriovenous malformations. MATERIAL AND METHODS: We have evaluated the results of stereotactic radiosurgery on 85 patients (48 females) with median age 34.5 years (range 4-70 years) treated at Haukeland University Hospital in Norway in 1989-96. Median follow-up time was 7 years 3 months (range 51-144 months). Data were obtained retrospectively from patient files. RESULTS: Haemorrhage was the initial symptom in 72 patients. The majority of lesions were located deep within the brain parenchyma or near critical structures. The minimum dose to the periphery of the malformation was 15 to 33.3 Gy in 30-70% isodose line according to the volume and location of the malformation. Complete obliteration was obtained in 65 of 85 malformations (77%) and in two of five patients who were retreated. 85% of the malformations smaller than 4 cm3; 50% of those larger than 4 cm3 were obliterated after the treatment. The majority of the malformations were obliterated between two and three years after radiation. Radiation-related side effects were observed in six patients. Five patients experienced new bleeding during follow-up. INTERPRETATION: Small and medium-sized arteriovenous malformations are successfully treated with stereotactic radiosurgery with an acceptable rate of radiation-related side effects and latency bleeding.

Adolescent↗
PubMed2002

Full remission of tardive dyskinesia following general anaesthesia.

A 44 year old woman with a severe drug induced tardive dyskinesia had previously been treated with a left thalamotomy and right deep brain stimulation. Thalamotomy abolished the right hemiballismus. Deep brain stimulation caused a moderate reduction of the remaining involuntary movements on the left side. After a minor orthopaedic operation under general anaesthesia, the dyskinesia disappeared completely, even with the deep brain stimulation turned off. The remission has now lasted for 41 months.

Adult↗
PubMedDate not supplied

Shunt revisions in children--can they be avoided? Experiences from a population-based study.

BACKGROUND: Shunt failure is by far the most frequent problem in children with shunts, and most of them will experience this condition at some point in their lives. In order to identify causes of shunt failure, and to compare multi-component and one-piece shunt systems, we analyzed retrospectively all pediatric shunt procedures in our Department during an 11-year period. The study does not deal with shunt infections. METHODS: We reviewed the records of all pediatric shunting procedures between January 1986 and December 1996. RESULTS: The study included 161 children operated for hydrocephalus with a total of 431 procedures. The procedures included 124 (29%) primary insertions, 10 (2%) reinsertions and 297 (69%) revisions; 206 (69%) of the revisions were due to shunt failures, of which 74 (36%) were caused by the failure of the surgical technique (misplaced ventricular catheters, disconnected shunts, or misplaced peritoneal catheters). CONCLUSIONS: Improvement of the surgical technique may reduce the incidence of shunt failures and revisions. The results obtained in a small department like ours do not seem to differ substantially from those obtained in more specialized departments with a larger patient group. Practical measures that may reduce the risk of shunt failures are suggested.

Adolescent↗