Heat production, nerve function, and morphology following nerve close dissection with surgical instruments.

BACKGROUND: The aim of the present study was to compare an ultrasonically activated instrument (US), monopolar electrosurgery, and bipolar electrosurgery (ES) with respect to heat production, nerve function, and nerve morphology following in vivo application. MATERIALS AND METHODS: The biceps femoris muscle of anesthetized rats was cut in a standardized manner longitudinally 1 mm adjacent to the sciatic nerve using US shears, a monopolar ES knife, or a bipolar ES scissors. Activation time and temperature were recorded continuously within 1-4 mm of the activation site ipsilateral and contralateral to the nerve with two thermoelectric microsensors. Temperature rise and time delay of reaching the temperature maximum, as an expression of heat spread within tissue, maximum temperature, and thermal dose (equivalent time of exposure at 43°C) were measured and calculated. A total of 49 functional experiments were conducted. The electromyographic (EMG) potential was recorded distally. Nerve dysfunction was defined as more than 10% loss of the evoked EMG amplitude. Forty-eight nerves were coded and submitted to blind histopathological examination, and morphological damage was graded on a 4-grade scale. RESULTS: The maximum temperature elevation and the thermal dose were significantly higher for the bipolar ES compared with the US instrument (p = 0.024, p = 0.049), and with much less variation of results for the US instrument. The monopolar ES maximum temperature and thermal dose were lower, but a very large variation occurred, probably as a result of more random electrical spread to the ground electrode and muscle motion artifacts. Functional loss was least common in the US group-without being significant-compared to bipolar and monopolar ES. Moderate and severe morphological damage was significantly less common in the US group than in the monopolar ES group (p = 0.041). We found no statistically significant correlation between the highest temperatures and the degree of morphological damage or functional loss. CONCLUSIONS: The temperature elevation depends strongly on the distance to the activated instrument. The bipolar ES scissors generates a higher maximum temperature and thermal dose with a greater variation in than the US. Functional loss and severe morphological damage were uncommon in all groups.

Update of the original HDLS kindred: divergent clinical courses.

BACKGROUND: Hereditary diffuse leukoencephalopathy with spheroids (HDLS) was first identified among a Swedish kindred with 17 cases. The average age of onset was 36 years. Autopsy in four cases revealed the presence of axonal spheroids. The causative gene is unknown. METHODS: We performed genealogical and longitudinal observations of the original kindred. Forty members were examined, five telephone-interviewed, and one of the original HDLS cases from 1984 was neuropathologically examined. The clinical course was documented. The cerebrospinal fluid (CSF) findings of two recently affected cases were examined, and one of those autopsied. RESULTS: Of those examined, two developed HDLS during our survey and 38 were healthy. Those interviewed by telephone were healthy. One had symptoms suggestive of HDLS in 1984, but autopsy during our survey showed no spheroids. This patient, two relatives healthy at our examination and one without symptoms at telephone interview had HDLS diagnoses in the 1984 report. Thus, four HDLS diagnoses were unconfirmed. The number of identified patients amounts to 15 among 75 individuals in four generations, including two recent cases who demonstrated a subacute multisystem encephalopathy in Case 1 and an insidious course in Case 2. CSF showed signs of neurodegeneration without inflammation, and autopsy verified HDLS in Case 1. CONCLUSIONS: Some HDLS cases were misdiagnosed with unspecified psychiatric diagnoses in affected relatives from the original 1984 publication. However, HDLS is an encephalopathy dominated by a frontal lobe syndrome with an inexorably progressive and fatal course, where the different symptomatology in two recent cases confirmed the existence of acute and chronic variants.

Acute aortic dissection in a patient with extremely low body mass index due to anorexia nervosa.

We report a case of successful surgical repair of an acute aortic dissection (Stanford Type A) in a severely malnourished 39-year old patient with anorexia nervosa (body mass index [BMI] 11.3 kg/m2) and essential hypertension. The case is of interest since 1) acute aortic dissection in patients with anorexia nervosa has not previously been described; 2) hypertension is extremely rare in patients with eating disorders; and 3) successful aortic repair in a patient with so low BMI has not been reported before. We conclude that extremely low BMI due to anorexia nervosa is not an absolute contraindication for major aortic surgery.

Expression of the class I interferon-related MxA protein in temporal arteries in polymyalgia rheumatica and temporal arteritis.

OBJECTIVE: The aim of this study was to assess the expression of the interferon type I (IFN-I)-associated MxA protein in polymyalgia rheumatica (PMR) and temporal arteritis (TA). METHODS: Non-inflamed temporal artery biopsies from 11 PMR patients were compared with biopsies from 13 patients given other diagnoses. Coded sections were screened immunocytochemically for MxA protein, CD83, CD68, CD3, and S100 protein. Inflamed temporal artery biopsies from four patients with TA were also investigated. RESULTS: Focal MxA expression was seen in non-inflamed arteries, more frequently in PMR than in controls (p = 0.0124). MxA expression was also more common in adventitial dendritic cells (DCs) in PMR (p = 0.0124). Activated adventitial DCs were detected in PMR. Focal MxA expression in the inflamed biopsies from the patients with TA was not related spatially to the inflammation. CONCLUSIONS: The expression of MxA protein in arteries from patients with PMR and TA shows that non-inflamed and inflamed vessel walls are influenced by IFN-I. Further studies are required to elucidate whether IFN-I plays a role in the initiation of PMR and/or TA, serving as a link between the innate and the adaptive immune responses, as in some other autoimmune disorders.

An uneven expression of T cell receptor V genes in the arterial wall and peripheral blood in giant cell arteritis.

The aim of the study was to investigate T cell receptor (TCR) usage at the time of diagnosis of giant cell arteritis (GCA) and to estimate the degree of clonality of T-cells infiltrating the lesion. Seven patients with biopsy-proven giant cell arteritis were included in the study. Immunocytochemistry in biopsies from the temporal arteries and flow cytometric analysis of peripheral blood lymphocytes (PBL) was performed using monoclonal antibodies specific for CD3, CD4 and CD8 and 13 TCR Valpha and Vbeta gene segment products. The CDR3 fragment length polymorphism was assessed by gel electrophoresis of PCR-amplified TCR segments. The T lymphocytes were found to be concentrated to the adventitia rather than the media or intima. Six of the seven patients with GCA had expansions of T lymphocytes, expressing selected TCR V genes in the arterial wall. None of these expansions was found in PBL. The infiltrating T-cells were poly- or oligoclonal. In conclusion, the dominating part of the inflammatory infiltrate in GCA emanates from the adventitial microvessels. There is an uneven expression of TCR V genes by T lymphocytes in the inflammatory infiltrates as compared to peripheral blood T lymphocytes at the time of diagnosis, consistent with an antigen-driven immunological reaction in the arterial wall.

Comparison of HIV-1 pol and env sequences of blood, CSF, brain and spleen isolates collected ante-mortem and post-mortem.

OBJECTIVES: HIV-1 infects the central nervous system (CNS) early in the course of infection. However, it is not known to what extent the virus evolves independently within the CNS and whether the HIV-RNA in cerebrospinal fluid (CSF) reflects the viral population replicating within the brain parenchyma or the systemic infection. The aim of this study was to investigate HIV-1 evolution in the CNS and the origin of HIV-1 in CSF. MATERIALS AND METHODS: Longitudinally derived paired blood and CSF samples and post-mortem samples from CSF, brain and spleen were collected over a period of up to 63 months from three HIV-1 infected men receiving antiretroviral treatment and presenting with symptoms of AIDS dementia complex (ADC). RESULTS: Phylogenetic analyses of HIV-1 V3, reverse transcriptase (RT) and protease sequences from patient isolates suggest compartmentalization with distinct viral strains in blood, CSF and brain. We found a different pattern of RT and accessory protease mutations in the systemic infection compared to the CNS. CONCLUSIONS: We conclude that HIV-1 may to some extent evolve independently in the CNS and the viral population in CSF mainly reflects the infection in the brain parenchyma in patients with ADC. This is of importance in understanding HIV pathogenesis and can have implications on treatment of HIV-1 patients.

Late cerebral graft versus host reaction in a bone marrow transplanted girl with Hurler (MPS I) disease.

A girl with Hurler disease (MPS IH) underwent allogeneic stem cell transplantation at 13 months of age with her one HLA-B antigen mismatch mother as donor. The procedure was complicated by cerebral hemorrhage and a ventricular-peritoneal shunt device was inserted. Mild GVH reactions were rapidly reversed. One year after transplantation ventriculitis was suspected and the shunt was replaced by a ventricular drainage catheter. Antibiotics had no effect and graft-versus-host disease (GVHD) was diagnosed. All symptoms were reversed by prednisolone and cyclosporine. Increased albumin and pleocytosis in the cerebrospinal fluid (CSF) normalized concomitantly. Electron microscopy of the CSF sediment showed debris consisting of numerous complex aggregates of thin lamellae and electron dense fragments with a tight lamellar texture. Biochemical analysis of the CSF sediment proved that the debris contained galactosylceramide and sulfatide. The electron microscopic and biochemical findings were interpreted to represent stripping of central myelin as a result of subacute GVHD in the central nervous system and its desquamation from the brain parenchyma into the ventricular CSF through the post-hemorrhage defect. From reversal of the GVHD at 2 years of age until follow-up at 10 years of age the clinical condition remained stable with no recurrence or deterioration.

A Western blot and molecular genetic investigation of the estrogen receptor beta in giant cell arteritis.

OBJECTIVE: The epidemiology of giant cell arteritis (GCA) may indicate a pathogenetic relationship between GCA and female sex hormone metabolism; GCA is two to four times more common in women compared with men. Our previous analyses gave no support for the hypothesis that the pathogenesis of GCA should be related to somatic mutations in the estrogen receptor alpha (ERalpha) gene. The object of the present study was to investigate the size of the estrogen receptor beta (ERBeta), and the size and nucleotide sequence of the ERBeta gene in temporal arteries in GCA. METHODS: The ERBeta protein was analyzed by Western blot technique and the ERBeta gene by RT-PCR and direct sequencing of the PCR product. RESULTS: Western blot analysis revealed an ERBeta of normal size. There were no aberrations in size or nucleotide sequence in the ERBeta gene in the GCA patients. CONCLUSION: The present observations gave no support for the hypothesis that somatic mutations in the ERBeta gene should be involved in the pathogenesis of GCA.

Early menopause, low body mass index, and smoking are independent risk factors for developing giant cell arteritis.

OBJECTIVE: To assess female sex hormone related variables in a group of women with biopsy positive giant cell arteritis and a control group. METHODS: 49 women with biopsy positive giant cell arteritis, aged 50 to 69 years at the time of diagnosis, answered a questionnaire on hormonal and reproductive factors. The same questions were answered by a large population of women from the same geographical area in connection with routine mammograms. The results were tested statistically, using logistic regression analysis of each variable adjusted for age, and a multivariate logistic regression analysis including age and the variables which differed significantly between giant cell arteritis and controls. RESULTS: From the multivariate logistic regression analysis, three independent variables were associated with an increased risk of having giant cell arteritis: smoking and being an ex-smoker (odds ratio (OR) = 6.324 (95% confidence interval (CI), 3.503 to 11.418), p<0.0001); body mass index (a reduction of 1.0 kg/m2 increased the risk by 10% (OR = 0.898 (0.846 to 0.952), p = 0.0003); and menopause before the age of 43 (OR = 3.521 (1.717 to 7.220), p = 0.0006). CONCLUSIONS: There was a significant association between hormonal and reproduction related factors and the risk of developing giant cell arteritis in women given the diagnosis before the age of 70. The results suggest a possible role of oestrogen deficiency in the pathogenesis of giant cell arteritis. To confirm the results, an extended study will be needed, including women older than 70.

Cell-type-specific expression of p53 and p21 in giant cell arteritis.

The aim of the present study was to investigate the expression of TP53 (p53) and CDKN1A (CIP1; p21) in the arterial wall in giant cell arteritis (GCA). Cross-sections from 18 temporal artery biopsies displaying GCA and 8 control arteries were double-stained with monoclonal antibody directed at p53 or p21 on the one hand and alpha-smooth muscle actin, CD68 (macrophage) or CD3 (T-cell) on the other. Nuclear p53 was expressed in CD68-positive cells and smooth muscle cells in 16 of the 18 inflamed arteries. P21-positive nuclei were found in CD68-positive cells in 14 biopsies and in smooth muscle cells in all the specimens. All p53-positive giant cells also contained p21-positive nuclei. In the giant cells, immunopositive nuclei were mixed with negative ones. CD3-positive T-cells did not express p53 or p21. Only one p53-positive smooth muscle cell nucleus was found in the non-GCA controls and, compared with GCA, p21 expression was noted in few smooth muscle nuclei. The presence of p53 and p21 in the same types of cell in GCA indicates that the former protein is functional; p21 expression is induced by wild-type, functional p53 but not by its mutant form. The current observations suggest cellular stress in GCA, the nature of which requires further investigation.

Parenchymal lesions in pharmacoresistant temporal lobe epilepsy: dual and multiple pathology.

OBJECTIVES: Dual pathology is reported in 5-30% of temporal lobe resections performed in pharmacoresistant epilepsy. Dual pathology may be of importance for surgical planning and also for the understanding of the pathogenesis of epilepsy. We describe the frequency of dual or multiple pathology, i.e. more than one histopathological diagnosis, in adults with temporal lobe resections. MATERIAL AND METHODS: Surgical specimens from 33 consecutive patients with resections including mesial as well as neocortical temporal structures were reviewed. All histopathological findings were recorded. Post-mortem specimens from 11 control subjects were also reviewed. RESULTS: Dual or multiple pathology was found in almost half of the epilepsy patients (48%). Hippocampal sclerosis was found in 25 patients (76%), malformations of cortical development in 15 (46%), of which 12 (36%) were microdysgenesis, and low-grade tumours in seven (21%). Apart from mild gliosis, there were no histopathological changes in the control specimens. CONCLUSION: Dual or multiple pathology was a common finding in this group of adults with temporal lobe resections. In order to increase our understanding of how aetiological factors may combine in the development of seizures, we consider it relevant and important to report all histopathological findings in epilepsy surgery series.

Microdysgenesis in epilepsy.

Microdysgenesis is a microscopic malformation of cortical development characterized by heterotopic neurones and abnormal cortical architecture. It has been described in primary generalized and partial epilepsy. Its significance in epileptogenesis is controversial, partly due to lack of consensus of diagnostic criteria. Different terms have also been used for the malformation. Several quantitative studies have been performed of the histopathological aberrations associated with microdysgenesis. A majority of the studies have revealed an increased number of heterotopic neurones in specimens from epilepsy patients. However, the quantitative values given for abnormal numbers of white matter neurones vary greatly between studies and there is no consensus yet on quantitative criteria for microdysgenesis. There have also been conflicting results from studies correlating microdysgenesis with clinical data. Both favourable and worse outcome after epilepsy surgery have been reported in patients with increased numbers of white matter neurones and microdysgenesis. While some studies have shown earlier seizure onset and increased frequency of mental retardation in patients with microdysgenesis, others have not. Differences in inclusion criteria and definition might contribute to the contradictory results. There is some evidence that microdysgenesis could be important in epileptogenesis, but the mechanisms involved remain unknown and difficult to investigate. A consensus on what histopathological criteria to use for the diagnosis of microdysgenesis is needed to explore this further and enable comparisons between centres. There are advantages and disadvantages both with quantitative stereological and with qualitative assessments. It is necessary to evaluate these in the decision on diagnostic criteria, if possible taking both qualitative and quantitative aspects into account.

Comparison of experimental nerve injury caused by ultrasonically activated scalpel and electrosurgery.

BACKGROUND: Iatrogenic nerve injury caused by heat from dissection instruments is a significant problem in many areas of surgery. The aim of the present study was to compare the risk of nerve injury for three different dissection instruments: monopolar and bipolar electrosurgery (ES) and an ultrasonically activated (US) instrument. METHODS: The biceps femoris muscle was cut in a standard manner just adjacent to the sciatic nerve using monopolar ES, bipolar ES or US shears. A total of 73 functional experiments were conducted in which the nerve was isolated, divided proximally, and stimulated supramaximally in 37 anaesthetized rats. The electromyographic (EMG) potential was recorded distally before and after each experiment. Nerve dysfunction was defined as more than 10 per cent loss of the evoked EMG potential. Fifty-nine nerves were examined histologically after dissection with the different instruments. The extent of heat damage was determined in four nerves that were divided with ES bipolar scissors and five that were divided with US shears. RESULTS: Reduction in the EMG potential was significantly more frequent in the monopolar ES group than in the US group. Morphological examination also showed significantly less nerve damage in the US group. CONCLUSION: US instruments may be safer than ES for dissection close to nerves.

Large-cell medulloblastoma in Aicardi syndrome. Case report and literature review.

An eight-year-old girl with Aicardi syndrome (AIC) developed signs of increased intracranial pressure. A clinical and radiological investigation revealed a tumor in the posterior fossa, which was resected. The histopathological diagnosis was large-cell medulloblastoma. Eight months later, she died of a local recurrence, despite treatment with chemotherapy and radiotherapy according to a PNET protocol. In addition to the growth of a large-cell medulloblastoma at the location of the primary tumor and the meningeal spread of the tumor, the autopsy revealed major cortical and subcortical malformations of the brain. Various benign (e.g., plexus papillomas) and malignant tumors (angiosarcoma, embryonic carcinoma, and hepatoblastoma) have been reported in connection with Aicardi syndrome. A genetic analysis of AIC suggests that the mutation is localized on the distal part of the short arm of the X chromosome, an area that may be of importance for tumor development. This is the first report of a primary malignant brain tumor -- large-cell medulloblastoma -- in a patient with Aicardi syndrome.

The epidemiology of biopsy-positive giant cell arteritis: special reference to changes in the age of the population.

OBJECTIVE: The incidence of giant cell arteritis (GCA) increases with age. The aim of the present study was to investigate whether the increasing incidence of biopsy-proven GCA in Göteborg, Sweden, could be explained in terms of a change in the age composition of the general population. METHODS: All cases of biopsy-verified GCA between 1976 and 1995 were recorded. The annual incidence was calculated for women and men aged 50 yr or older and its relationship with the age composition of the general population was tested statistically. RESULTS: There was a significant positive correlation between age and the risk of developing GCA. In the general population, there was a shift towards higher age; in 1976, the mean age of people 50 yr or older was 63.2 (men) and 65.0 (women), whereas in 1995 it was 65.0 (men) and 68.1 (women). After compensating for this, the incidence of biopsy-proven GCA still increased significantly. Moreover, for women aged 50 yr or older, the risk of developing the disease increased more among younger subjects than older ones. CONCLUSIONS: The increase in the incidence of biopsy-proven GCA between 1976 and 1995 could not be explained merely in terms of the increasing age of the general population. It is most probably related to an increase in the influence of other factors.

Giant cell arteritis: epidemiological clues to its pathogenesis and an update on its treatment.

Giant cell arteritis (GCA) is a chronic systemic vasculitis with a marked female predominance and restriction to old age. The disease process distinctly targets large and medium sized arteries, preferentially the aorta and its extracranial branches. Morphological observations indicate that the age and sex distribution of GCA is related to the occurrence of degenerative changes in the arterial wall. GCA is not a truly infectious vasculitis. However, an infection might be a triggering factor. Different centres report an increase in GCA incidence, but annual fluctuations have not been shown to be statistically significant. However, significant seasonal variations have been observed by several groups. The mortality is not increased in adequately treated patients. Although, alternative steroid-sparing agents have been proposed, corticosteroids are still the first treatment choice.

Widespread microdysgenesis in therapy-resistant epilepsy--a case report on post-mortem findings.

Microdysgenesis is a subtle malformation, which is often found in specimens from epilepsy surgery. It is, however, not clear whether the changes are focal or diffuse. A recent autopsy case offered an opportunity to investigate whether microdysgenesis found after temporal lobe surgery was focal or widespread in the brain. The entire brain of a 20-year-old patient who died suddenly and unexpectedly was examined histologically. Microdysgenesis had previously been diagnosed after a left temporal lobectomy performed because of therapy-resistant seizures. A light microscopic examination was performed on specimens stained with Luxol-fast blue-cresyl violet and polyclonal antibodies to glial fibrillary acidic protein. Widespread microdysgenesis with irregular nerve cell distribution in the cortex and an increased number of nerve cells in cortical layer I and in the white matter was found in the right temporal and parietal lobes and bilaterally in the frontal and occipital lobes. The post-mortem examination confirmed the previous diagnosis of microdysgenesis and showed that the changes were widespread in a patient who was operated on because of focal epilepsy.

Calcification of the internal elastic membrane in temporal arteries: its relation to age and gender.

OBJECTIVE: To investigate the age and sex distribution of calcifications of the internal elastic membrane (IEM) in temporal arteries. METHODS: Calcifications of the IEM were assessed light-microscopically in temporal arteries from 40 women and 21 men, aged 51 or more, who were known not to have giant cell arteritis (GCA). Their relation to age and the difference between women and men were tested statistically. RESULTS: The IEM calcifications differed morphologically from the calcifications in Mönckeberg's mediosclerosis and atherosclerosis. They increased significantly with age and were 2.62 times more common in women than men. CONCLUSION: Previous morphological studies indicate that the inflammatory process in GCA is initiated by a foreign-body, giant-cell attack on calcifications of the IEM. The present study showed that IEM calcifications in non-GCA controls show an age and sex distribution similar to that of GCA morbidity. The results may indicate that the presence of IEM calcifications in the general population influences the age and sex distribution of GCA. Furthermore, the findings support the hypothesis that the calcifications, although not disease specific, may play a pathogenetic role in the latter.