Showing papers in "Acta Neurologica Scandinavica in 1988"

Increased production of interferon gamma and tumor necrosis factor precedes clinical manifestation in multiple sclerosis: do cytokines trigger off exacerbations?

Abstract: We have carried out a longitudinal study of interferon (IFN) and tumor necrosis factor (TNF) using a whole-blood mitogen stimulation assay in 20 multiple sclerosis (MS) patients and in a healthy control group. We set up individual profiles and the results were quite constant for each individual, both in healthy donors and in the patients in remission. Before exacerbations, however, we found an increase of IFN-γ and TNF production preceding clinical symptoms by a maximum of 2 weeks. In benign cases, the increase disappeared rapidly, even before the appearance of symptoms, whereas we found sequelae whenever the increase persisted during weeks. In chronic progressive patients, we frequently found intervening increases. It may be that IFN-γ and TNF trigger off exacerbations at a very early stage and that these cytokines may also play a role in maintaining disease in chronic progressive and invalidating forms.

Calcium accumulation by glutamate receptor activation is involved in hippocampal cell damage after ischemia.

Abstract: Rats exposed to 10 min of complete cerebral ischemia develop necrosis of the CA-1 region of the hippocampus after 2-3 days. We studied the involvement of synaptic transmission for this process by ablation of the afferent input (which is mainly glutamatergic) to CA1 by bilateral destruction of CA-3 neurons (Schafferotomi). The deafferentiation completely prevented the ischemic nerve cell destruction as revealed by histological studies after 6 days. The role of intracellular Ca++ overload was assessed by measurement of the interstitial Ca++ concentration. In control animals the interstitial Ca++ concentration decreases abruptly to 10% of the initial value 1.6 min after the onset of ischemia. The denervated hippocampi, however, showed no decrease during the 10 min of ischemia and hippocampi injected with 2-amino-5-phosphovalerate (APV), a competitive antagonist of the glutamate N-methyl-D-aspartate (NMDA) receptors, displayed a significantly reduced decrease (45% of the initial value) during ischemia. It is concluded that calcium influx via the glutamate-operated channels during the ischemic period is an important link in the development of ischemic brain cell damage.

Mechanisms of brain damage in focal cerebral ischemia.

Abstract: Ischemic stroke is a major disabling disease. There are 500,000 new cases in U.S. every year, and the middle cerebral artery (MCA) is the artery most often occluded. In this paper recent results of experimental MCA occlusion are reviewed, with special emphasis on those factors contributing to irreversible damage. Occlusion of MCA in the rat causes a pronounced decline of flow in the neostriatum to less than 10% of normal. The area of low flow is surrounded by a zone 0.2-0.5 mm wide, across which blood flow increases steeply. Beyond this zone, changes in flow are more gradual, and perfusion is reduced to about 1/3 of normal in the adjacent ipsilateral cortex. The MCA occlusion leads to a sharply demarcated infarct and to scattered neuronal injury in the adjacent cortical tissue. It is suggested that the ischemic core is identical with the tissue infarct, i.e. that it is the initial pattern of blood flow which determines the volume and topography of infarction. Waves of spreading depression are detected in the cortical low perfusion area during the first hours of MCA occlusion, and glucose consumption is increased, presumably due to an increased demand for ionic transport. In hyperglycemic animals, the number of spreading depressions is reduced as is the glucose consumption. The repeated waves of spreading depression in combination with partial energy depletion may induce selective neuronal injury in the peri-infarct zone, a suggestion which finds support in the fact that hyperglycemia ameliorates neuronal injury around the infarction.

Valproate: a new drug in migraine prophylaxis.

Abstract: 22 patients with severe migraine resistant to previous prophylactic treatments participated in a prospective open trial of valproate in migraine prophylaxis; 17 had common and 5 classic migraine. The attack frequency was from 4 to 16(30)/month (1 patient suffered from attacks every day). The dose of valproate was 600 mg twice a day from start of treatment, successively adjusted to a serum level about 700 mumol/l. Follow-up was from 3 to 12 months; 11 patients were free from migraine attacks, 6 had a significant reduction of the frequency; in one patient there was no effect; 4 dropped out because of lack of cooperation; 3 who had been free from migraine for 3 months, participated in a withdrawal experiment during which they all experienced relapse. After reinstitution of valproate the attacks disappeared again. How valproate acts in migraine prophylaxis is not known, but this prospective open trial demonstrates that valproate has an appreciable prophylactic effect in patients suffering from severe migraine, and calls for controlled clinical trials.

Course and prognosis of chronic progressive multiple-sclerosis - results of an epidemiological-study

Abstract: In studies on the natural course of multiple sclerosis (MS), several forms of the disease are distinguished The most important are the relapsing remitting and the chronic progressive forms The relationship between these remains unclear In a prospective epidemiological survey we studied the course of MS using the year in which the chronic-progressive phase started as a landmark The reliability of this “year of progression” was examined in an observer agreement study Data were acquired from 342 patients Progression of the handicap was most rapid in case of a secondary progressive course, female sex, high relapse rate in the preceding remitting phase and “year of progression” at a higher age Survival after the “year of progression” was lowest in the secondary progressive group Determining the “year of progression” seems to be significant for the prognosis

EEG in demented and non-demented parkinsonian patients

Abstract: The electroencephalograms (EEG) of patients with Parkinson's disease (PD) were evaluated in relation to age, mental status and motor disability. Abnormalities, particularly mild slowing, were observed in 34% of 128 patients and more frequently in the elderly. While a slowing in occipital background activity was more frequent in demented patients, a statistically significant association was also observed between the degree of motor disability and the frequency of slowing in occipital background activity in mentally intact patients. This correlation may suggest that subcortical structures (involved in motor control) influence occipital background activity.

Reduced prealbumin (transthyretin) in CSF of severely demented patients with Alzheimer's disease

Abstract: Prealbumin (transthyretin) quantified in CSF was negatively correlated with degree of dementia in 24 patients with dementia of Alzheimer type (DAT). There was neither a significant correlation between prealbumin in serum and degree of dementia nor between prealbumin in CSF and number of T lymphocytes in serum. There was no such relationship in 7 patients with multiinfarct dementia. Prealbumin was also quantified in 4 non-demented control groups, one consisting of 14 age- and sex-matched neurological patients, 17 with MS, 6 with ALS and 10 patients who had had a subarachnoid hemorrhage. Prealbumin was significantly lower in the last group. The study suggests that there may be a relationship between prealbumin levels in cerebrospinal fluid and degree of dementia. It is suggested that this may be caused by affection of the choroid plexus.

Tomographic cerebral blood flow measurements in patients with ischemic cerebrovascular disease and evaluation of the vasodilatory capacity by the acetazolamide test.

Abstract: Cerebral blood flow (CBF) was measured in a series of patients with ischemic cerebrovascular disease using xenon-133 inhalation and single photon emission computer tomography. The spontaneous course of CBF changes in a consecutive series of stroke patients was evaluated. A quite heterogeneous pattern of flow changes was observed: In patients with large cortical/subcortical infarcts, extensive hypoperfused areas were observed, often significantly larger than the corresponding hypodense lesion on the CT scan. Smaller CT lesions caused relatively smaller flow changes. Patients with lacunar infarcts showed only a discrete reduction of CBF, but comprising most of the ipsilateral hemisphere. Repeated CBF studies in the chronic phase showed, that the clinical improvement commonly noted in stroke patients is not related to a CBF increase. On the contrary, the CBF lesions tended to become somewhat larger and more demarcated even in cases where the finding of a normal angiogram and a transient state of hyperemia suggested a dissolution of the intracerebral embolus. The pathogenetic mechanisms for these persisting low flow areas in CT intact structures was discussed. One possibility was a selective neuronal cell damage in the peri-infarct areas caused by the ischemic insult. Such lesions would leave the structures macroscopically intact, but decrease both the metabolic demands and CBF. However, this interpretation finds little support in recent microscopic neuropathological studies in man. A more likely possibility was then considered to be disconnection (diaschisis) where the reduced flow is due to a decreased neuronal function caused by undercutting of afferent or efferent nervefibers. A crossed cerebellar diaschisis was observed in all patients with major infarcts in the forebrain. These findings were observed already in the acute phase, but persisted quite unchanged throughout the subacute and chronic phases. The patients with lacunar infarcts showed cerebellar diaschisis in the acute phase only, suggesting that a transient suppression of remote areas is possible too. In order to differentiate between permanent flow changes caused by a functional impairment and a possible hemodynamic component, CBF was measured before and after administration of a potent cerebral vasodilator, acetazolamide (Diamox). In normal cases tested with Diamox, an even CBF increase is noted throughout the hemispheres, while the cerebral metabolic rate for oxygen remains stable. In patients having a severe stenosis or occlusion of the internal carotid artery, this vasodilatory stress test will identify the patients having poor collateral capacity via the circle of Willis.(ABSTRACT TRUNCATED AT 400 WORDS)

Motor neuron disease in Cantabria.

Abstract: — Sixty-two patients with motor neuron disease (MND), encompassing amyotrophic lateral sclerosis (ALS), progressive bulbar palsy (PBP) and progressive muscular atrophy (PMA), were selected from within a defined area (Cantabria) in northern Spain, from 1974 to 1985. The annual incidence of MND was 1.01 per 100,000 inhabitants and the prevalence rate was 3.52 per 100,000. The male to female ratio was 1.78:1. Age-specific incidence rates increased with advanced age, with a maximum between 60 and 69 years for males and over 70 years for females. The median age at onset was 60.5 years. The average interval between the onset symptoms and diagnosis was 11 months. Fifty-three per cent of the patients had conventional or pseudopolyneuritic ALS, 36% had PBP and 11% had PMA. There were three familial cases. Two PMA patients had had acute poliomyelitis. The mean duration of the disease was 26.6 months and was significantly longer in males aged under 60 years. The survival rates in 50 patients with adequate follow-up were 18% after 5 years from onset and 6% after 10 years.

Ocular myasthenia: diagnostic and therapeutic problems.

Abstract: Forty-eight patients with purely ocular myasthenia were studied. Tensilon test was positive in 46 patients (95%); decremental response from limb muscles was present in 24 patients (50%); anti-AChR antibodies were detected in 20 patients of 44 (45.5%). Twenty-two patients underwent thymectomy, 18 were given corticosteroids, 42 received AChE drugs. At the end of the observation period, 8% of the patients were in remission, 67% were improved, 25% were unchanged. In our experience, the diagnosis of ocular myasthenia relies mainly on clinical data; AChE drugs are not very effective in extrinsic ocular muscles; indications for thymectomy should be restricted to thymoma cases and, perhaps, to patients in the early stages of the disease, within the first year of onset; corticosteroids are effective in most cases, but relapses after withdrawal are not uncommon.

Skeletal muscle function in primary fibromyalgia. Effect of regional sympathetic blockade with guanethidine

Abstract: Muscle fatigue is the most disabling symptom in primary fibromyalgia (PF), which in addition is characterized by generalised pain and muscle stiffness. In order to assess whether the fatigue is of central and/or peripheral origin, skeletal muscle function was studied by measuring maximum voluntary hand grip strength, and by measuring various contraction characteristics in the adductor pollicis muscle after electrical stimulation of the ulnar nerve. The PF-patients were also studied after a regional sympathetic blockade of the forearm with guanethidine. A lower hand grip strength was found in the PF-patients compared to the controls, before as well as during the sympathetic blockade. The developed force, measured during electrical stimulation, did not differ between patients and controls. A lower muscle relaxation rate was found in the PF-patients. The relaxation rate increased in the PF-patients during the sympathetic blockade. The results indicate both a central and a peripheral cause of muscle dysfunction. Activity in the muscle sympathetic system may be one link in the chain of events that leads to muscular symptoms in PF.

Spinal cord restitution following compression injuries in rats

Abstract: Spinal cord compression injuries were produced in rats by applying weights to a plate 2.2 × 50 mm in size, placed on the exposed midthoracic dura covering the spinal cord. The influence of force and duration of compression was studied by using 3 different weights, 20, 35 and 50 g, applied for 1, 5 and 10 min. Postoperative neurological function was tested by the inclined plane method and the rats were observed for 3 weeks. Neurological impairment increased with force and duration of compression. It is therefore reasonable to conclude that patients suffering from spiral cord injury should be investigated immediately for signs of persistent cord compression. If this is present, early decompression might be of value, although nothing is known in man concerning the limits of force and duration of compression permitting postoperative neurological recovery.

Monoamine re-uptake sites in the human brain evaluated in vivo by means of 11C-nomifensine and positron emission tomography: the effects of age and Parkinson's disease.

Abstract: Six patients with Parkinson's disease, selected to cover a range of clinical features, and 7 healthy volunteers aged 24-81 years, were examined by positron emission tomography after i.v. injection of racemic 11C-nomifensine, a catecholamine re-uptake blocking drug. After injection the radiotracer, radioactivity was rapidly distributed to the brain. The highest accumulation of radioactivity was found in areas rich in dopaminergic and noradrenergic innervation, such as the striatum and the thalamus. In regions with negligible dopaminergic and noradrenergic innervation, such as the cerebellum, radioactivity was lower and evenly distributed. In all investigated brain regions a marked age-related decline in 11C-nomifensine-derived radioactivity relative to the cerebellum was observed in the group of healthy volunteers. Parkinsonian patients did not show such a decline with age. In the group of parkinsonian patients with mainly unilateral involvement, the contralateral putamen exhibited the most pronounced decrease. Only the 3 parkinsonian patients aged 63 and younger showed markedly lower 11C-nomifensine binding in striatal areas than age-matched healthy volunteers. 11C-nomifensine seems to be a valuable tool for investigating noradrenergic and dopaminergic re-uptake sites in vivo. Further achievements will most likely be made when the active enantiomer becomes available.

Cognitive evoked potential (P300): a metric for cerebral concussion.

Abstract: Cognitive impairment has been reported to occur in minor head injury (concussion). The value of the P300 evoked potential as a measure of cerebral concussion was studied in 20 patients with minor head injury and compared with the data from 20 normal subjects. Significant abnormalities of the P300 latency and amplitude were noted in these patients in the post-concussion period. The abnormalities improved completely on repeat testing. The correlation of the P300 to other parameters of head injury is discussed. The P300 constitutes a simple laboratory test that is sensitive measure of cerebral dysfunction in concussive head injuries.

Cocaine‐related intracranial hemorrhage. Report of nine cases and review

Abstract: — Nine cases of intracranial hemorrhages related to cocaine usage are presented. Another 5 cases from the literature are reviewed. The relationship between severe cocaine-induced hypertension, and the development of subarachnoid or intracerebral hemorrhages is noted, and apparently is related to sudden transient increases of blood pressure related to cocaine use.

"Chronic painter's syndrome". A reanalysis of psychological test data in a group of diagnosed cases, based on comparisons with matched controls.

Abstract: Twenty solvent-exposed workers, most of them painters, had been diagnosed as cases of toxic encephalopathy in 1978/79. Two years later they were re-examined with an extensive battery of neuropsychological tests. Their performance was unchanged on retesting. We have now compared their test results with those of non-exposed control subjects. Previous impressions of significant intellectual impairment in the solvent-exposed patients could not be confirmed when the influence of age, education, and intelligence was taken into consideration. The present group with presumed toxic encephalopathy is assumed to be representative of other patients who were similarly diagnosed in our department. The presently reanalyzed cases had been diagnosed as brain damaged and reported as such in the literature. Thus, they may have contributed to the formation of the concept of the "chronic painters' syndrome" with dementia.

Epidemiology of multiple sclerosis: incidence and prevalence rates in Denmark 1948–64 based on the Danish Multiple Sclerosis Registry

Abstract: The Danish Multiple Sclerosis Registry (DMSR) is a national register based upon the ethnically homogeneous Danish population of about 5 millions. The DMSR was founded in 1956 following a nationwide Danish prevalence survey of MS in 1949 and a continuous registration of incident cases of MS since January 1, 1948. Included in DMSR are all Danish cases of MS (or suspicion of MS) diagnosed by a neurologist or a department of neurology. The sources of notification are the 22 neurological departments in Denmark, the National Patient Registry, the neuropathological departments, the Registry of Causes of Death, and, up to 1975, the Disablement Insurance Court. Notified cases which do not comply with the standardized diagnostic criteria of the DMSR are excluded. An estimate of the completeness of the DMSR is 90-95% and the validity is around 94%. Age- and sex-specific incidence rates of MS for the interval 1948-64 are presented. The crude annual incidence rate of MS in Denmark was in the year 1948-64 4.42 per 100,000 population, 22% higher in females than males. There was a significant geographical variation of incidence rates and a significant downward trend in incidence rates during the interval, whereas the prevalence rates showed a slight increase.

Clinical course and prognosis of pseudotumor cerebri. A prospective study of 24 patients.

Abstract: In a prospective study, 24 consecutive patients with pseudotumor cerebri were followed for an average of 49 months with regular neurologic and ophthalmologic examinations. At the first examination the intracranial pressure was between 18 and 45 mm Hg; several patients had pressure waves up to 70 mm Hg and decreased conductance to cerebrospinal fluid outflow. In the majority, medical treatment, usually with diuretics and acetazolamide, induced a rapid relief of symptoms, but about 25% had a more protracted disease course with persistent headache, asthenia and memory disturbances interfering with daily life. Five patients required a shunt operation. Chronic changes of the optic disc developed in nearly half the patients, and one had optic atrophy and severe visual impairment. Repeated measurements of the intracranial pressure and conductance to cerebrospinal fluid outflow showed that abnormalities can persist for a long time, even in cases without symptoms of intracranial hypertension.

Methodological analysis of an experimental spinal cord compression model in the rat.

Abstract: A technique for producing graded spinal cord compression injuries in rats is described. A metal plate 2.2 x 5.0 mm in size is applied to the exposed spinal dura and loaded with weights. Neurological function is tested postoperatively on an inclined plane. Reading of the maximal angle of rat performance on this plane was found reproducible on comparison between different observers. Laminectomy per se had a minimal effect on the performance. Compression of 35 g for 5 min caused a pronounced but incomplete injury, with almost total recovery within 14 days and with no difference between animals on artificial respiration and those breathing spontaneously. Animals whose spine was fixed during the compression had a better outcome than those without such fixation.

Risk factors in lacunar syndromes: a case-control study

Abstract: The association between some hypothetical risk factors (previous TIA, hypertension, ECG ischemic abnormalities, diabetes, cigarette smoking, atrial fibrillation, hypercholesterolemia, hypertriglyceridemia, high hematocrit) and lacunar syndromes has been evaluated by a matched sample case-control study involving 108 consecutive, incident cases with lacunar syndrome and 216 hospital control subjects, matched for sex and age. A significant increase of Relative Risk (RR) has been shown for: 1. Previous history of TIA; 2. Hypertension; 3. Smoking; 4. Diabetes. No relevance was shown for: 1. Atrial fibrillation; 2. Hypercholesterolemia; 3. Hypertriglyceridemia; 4. High hematocrit. The analysis of the triplets of subjects (1 case + 2 controls) without hypertension showed a significant RR increase for: 1. Previous history of TIA; 2. Ischemic cardiac abnormalities; 3. Atrial fibrillation. Such findings support the hypothesis that, in a minority of cases with lacunar syndrome, the pathogenetic mechanism could be different from occlusion of penetrating arteries in hypertensive patients.

Guillain‐Barré syndrome: diagnostic criteria, epidemiology, clinical course and prognosis

Abstract: Thirty-four patients were identified with Guillain-Barre syndrome (GBS) on review of 266 neuropathy cases admitted to a Copenhagen county hospital from June 1977 to January 1984. The age-adjusted incidence rate of GBS is 2.0 x 10(-5) years-1. The natural history of the disease, antecedent events, symptoms and signs, autonomic dysfunction, sequelae, CSF findings and mortality are described. Six cancer patients with GBS differed significantly from the non-cancer patients in a more protracted disease course and failure to improve. The National Institute of Neurological and Communicative Disorders and Stroke (NINCDS) criteria for the diagnosis of GBS are discussed, and it is concluded that the criteria, although useful in comparative studies, are too restrictive when used in clinical practice.

Localized CNS brucellosis: report of 7 cases.

Abstract: Seven patients with brucellar infection localized in the central nervous system (CNS) are reported. This series represent 3.5% of all brucellosis cases in our hospital. There was a conspicuous absence of systemic signs and symptoms. The clinical course was characteristically protracted. Meningitis (acute, chronic, transient and recurrent) and progressive myeloradiculopathy were the 2 clinical patterns. Cranial nerve neuropathy was frequent, eight nerve involvement being present in 4 cases; transitory ischemic attacks and subarachnoid haemorrhage occurred in 2. Routine laboratory determinations were negative or non-specific. Cerebrospinal fluid (CSF) findings included hypoglycorrhachia, lymphocytic pleocytosis and hyperpro-teinorrhachia. There was also a remarkable increase in the gamma-globulin and IgG values with morphology of oligoclonal bands in CSF electrophoresis. Brucella agglutination titers were low or absent in serum and/or CSF. By contrast, Coombs tests were always positive and higher titers were found in serum and CSF. After treatment a persistent CSF positive Coombs test at low titers together with an isolated increase in CSF gamma-globulin and IgG values were detected in cured patients. Brucella blood cultures were negative, but CSF cultures were positive in four cases. Rifampin and doxycycline seems to be the treatment of choice. These agents must be maintained at least for 4 months in order to avoid relapses. Corticosteroids may be helpful at the beginning of treatment. Outcome is generally favourable in this disorder. We conclude that clinical and biological characteristics of localized CNS brucellosis are in accordance with those already described in other types of localized brucellosis.

Tizanidine versus baclofen in the treatment of spasticity in multiple sclerosis patients

Abstract: — Sixteen patients suffering from spasticity due to multiple sclerosis were treated with baclofen and tizanidine in a partially blind cross-over study. No significant difference in efficacy was found. The most striking difference was seen in the side-effects: baclofen frequently caused more or less severe muscle weakness and even falling during walking and standing. Treatment with tizanidine produced an apparent improvement of mobility in some patients suffering from moderate or marked paresis associated with a marked spasticity of their legs. Isometric muscle strength did not show any significant changes during either treatment. The different impact of baclofen and tizanidine on mobility and weight support seems to be related to their different site of action in spasticity.

The course of epilepsy during pregnancy: a study of 78 cases.

Abstract: We have compared frequency and severity of epileptic seizures during pregnancy with the 9 months prior to pregnancy in 66 patients with a total of 78 pregnancies. Data on total number of seizures and major seizures are analysed separately. No statistically significant differences between frequency before and during pregnancy were found. Cases with seizures before pregnancy tended to have seizures during pregnancy, but there was no association between occurrence of seizures prior to pregnancy and increased frequency during pregnancy. There was no evidence that seizures became more severe during pregnancy. No relationship was found between type of epilepsy and change in seizure frequency during pregnancy. The data suggest that our therapeutic interventions may have influenced seizure frequency in at most a minority of cases. Serum concentrations of the anti-epileptic drugs were monitored regularly during pregnancy. Only data on patients on constant drug dosages and, therefore, presumedly with the mildest seizure disorders were analysed. In the majority of cases there was a decrease in drug levels during pregnancy. Most cases tolerated this decrease without an increase in seizure frequency. On the other hand, most cases with increased frequency also had decreased drug levels.

Risk and benefit in the surgery of epilepsy: complications and positive results on seizures tendency and intellectual function.

Abstract: — A review of complications in a series of 560 consecutive craniotomies for surgery of epilepsy shows the mortality to be nil and the morbidity very low. Results on the seizure tendency for temporal resections are presented with emphasis on extent and modalities of removal. In this series the success/failure ratio was in the order of 80/20%. Patients with-right sided removal tend to do better than those with left-sided operations. Removal of the hippocampal formation appears to significantly improve the results. Patients studied with intracerebral electrodes tend as a group to do better than those operated without depth electrodes. Anterior temporal resection is usually followed by a significant increase in intellectual function when measured one year after surgery.

Epidemiology of stroke in Lund-Orup, Sweden, 1983-85. Incidence of first stroke and age-related changes in subtypes.

Abstract: The incidence of stroke in the hospital district of Lund-Orup (total population 200,191), the local uptake area of the University Hospital, Lund, was studied. Between January 1 1983 and December 31 1985, there were 1054 cases of first stroke. Age adjusted (to Swedish Dec 1983 population) incidence rates were 221.2 for males, 195.8 for females, and 208.3 for total population (per 100,000 and year). Case-fatality ratio by 30 days was 17.5%. Atherothrombotic infarction was the most common subtype (58.4%), followed in frequency by cardiac embolism (30.6%), intracerebral hemorrhage (8.3%) and subarachnoid hemorrhage (2.7%). The most important change in the distribution of subtypes with age was an increase in the proportion of cardiac embolism from 13% in the youngest to 44% in the oldest age groups. The present study underscores the importance of careful determination of subtypes of stroke in future epidemiological studies.

Atherosclerotic carotid disease in asymptomatic individuals: An histological study of 53 cases.

Abstract: The carotid bifurcation was studied histologically in 53 consecutive autopsies from persons over 65 years of age who were asymptomatic for carotid artery disease and showed no carotid related brain infarcts. The autopsy material is considered to be representative for the population in Oslo. The area stenosis was determined morphometrically in histological sections and the cases were examined for the occurrence of atherosclerotic plaques, calcifications, plaque hemorrhages, ulcerations, and mural thrombi. About one half of the cases had more than 50% stenosis. There was increasing frequency of plaque hemorrhages, ulcerations and mural thrombi with increasing stenosis. When the stenosis exceeded 60%, most cases had small recent and old plaque hemorrhages and one half had ulcerations and mural thrombi. In addition, numerous healed ulcerations and organized thrombi were seen. It is concluded that plaque complications are frequent in cases with stenosis and that most of them apparently heal without giving rise to symptoms. The presence of such lesions in asymtomatic cases must therefore be interpreted with caution.

Hemodynamic significance of internal carotid artery disease

Abstract: Neurologic symptoms in the region of an internal carotid artery stenosis are considered to be embolic in most instances. Only in a subgroup has carotid occlusive disease with impairment of the collateral supply, caused a state of hemodynamic failure with marked reduction of perfusion pressure. Though unproven, it is reasonable to assume that without surgical intervention, the risk is higher than average for patients with hemodynamic failure. Equally, should there be any postoperative improvement of cerebral blood flow or neurologic deficits, it should be looked for in this group. Thus, it is necessary to distinguish those with low perfusion pressure from the population of patients with carotid artery disease. Preoperative clinical evaluation and direct visualization of the carotid bifurcation should be supplemented by indirect physiological tests which allow assessment of collateral perfusion. Examination of periorbital flow direction or oculoplethysmography could be used as a screening procedure. Negative tests most certainly rule out any severe pressure gradient across the stenosis, irrespective of the luminal reduction. A positive result, on the other hand, should be further quantified since most indirect tests become positive at relatively small pressure gradients. Studies of cerebral blood flow at rest and during cerebral vasodilation makes it possible to identify patients with severe reduction of cerebral perfusion pressure. Such hemodynamic failure of one hemisphere may be identified in most cases by a conventional non-invasive xenon-133 technique and stationary detectors. Smaller focal regions of hypoperfusion may be identified by computer emission tomography, either by the detection of single-photon emission or by paired detection of annihilation photons. Endarterectomy does improve cerebral hemodynamics in terms of increased flow through the reconstructed vessel and elimination of pressure gradients. The cerebral blood flow, though remains unchanged in the majority of patients, at least when measured at baseline. Only in those patients with a reduction in perfusion pressure can a significant improvement in baseline flow occur. Flow reserve determined by cerebral vasodilation, however, will improve in most patients with hemodynamic failure. In addition, some patients in the low-pressure group develop marked, but temporary, hyperperfusion after reconstruction of very high grade carotid stenosis. This is considered a result of chronic low perfusion pressure with subsequent loss of autoregulation, and autoregulatory control is first regained after some days.(ABSTRACT TRUNCATED AT 400 WORDS)

Diagnostic value of quantitative sensory testing (QST) in carpal tunnel syndrome.

Abstract: The initial sensory symptoms of carpal tunnel syndrome (CTS) are usually intermittent and the clinical neurological examination is often normal. The aim of the present study was to determine the rate of impairment of different somatosensory modalities in CTS by means of the following tests: vibrametry, tactile pulses, von Frey hairs, two-point discrimination (2-PD), graphesthesia and warm and cold perception thresholds. The material consisted of 33 hands with CTS from 22 patients. Each of the first 3 tests was abnormal with elevated thresholds in 17 CTS hands (52%), 2-PD was abnormal in 10 hands (30%), graphesthesia in 8 hands (24%), and warm and cold thresholds in only 5 hands (15%). There was an overlap so that at least one test was abnormal in 27 of the 33 CTS hands (82%). Thus, impairment of sensibility can be demonstrated in a majority of patients with CTS if more than one test is applied. Vibrametry and von Frey hairs are recommended instead of the commonly used 2-PD, since abnormality was more often revealed and since they are equally easy to apply. No individual test was sensitive enough to qualify as a diagnostic criterion when it was applied with the hand in resting position. A significant increase in both sensitivity and specificity can be expected for any test if it is combined with provocation, such as wrist flexion, as'has been demonstrated for vibrametry (1).

Cognitive changes as early signs of HIV infection.

Abstract: Neuropsychological examination was performed on 13 patients and 10 matched controls to assess the brain involvement of patients with human immunodeficiency virus (HIV) infection. HIV-infected patients showed a significant decline in visuomotor, visuoconstructive and practical abilities as well as in motorfree visuospatial performance and repeating a long sentence. These findings could not be explained by the concomitant mental depression of these patients. Neither were they associated with any particular stage of HIV infection. The results suggest that mild cognitive changes may be detected even in the early stages of HIV infection, when examined by appropriate neuropsychological methods.