[Changes in an electroretinogram and biochemical parameters of tear in simulated rabbit retinal ischemia].

The pattern of functional impairments and the antioxidative and antiproteolytic status of tear were studied, by experimentally simulating retinal ischemia in rabbits and during treatment with Selecarten. Simulated retinal ischemia resulted in the development of persistent (up to 3 weeks) retinal electrogenetic disorder. Selecarten instillations produced a moderate neuroprotective effect, by positively affecting retinal function early after ischemia stimulation and accelerated the recovery of retinal electrogenesis late after laser coagulation of retinal vessels. The altered metabolic processes were characterized by an increase in the tear antiproteolytic potential. The antioxidative activity and the activity of a2-macroglobulin proteolysis inhibitor increased in the tears of Selecarten-treated rabbits.

Sympathetic dysfunction of central origin in patients with ALS.

Amyotrophic lateral sclerosis (ALS) is a severe, progressive disease affecting both the central and peripheral parts of the motor nervous system. Some studies have shown unequivocal indications of a more disseminated disease also affecting the autonomic nervous system. We therefore evaluated the centrally and peripherally mediated autonomic vascular reflexes by (i) the local 133-Xenon washout technique, and (ii) the head-up tilt table test. The results correlated to clinical scores. We examined nine ALS patients and 15 age-matched controls. The 133-Xenon washout test showed a significant reduction in the centrally mediated sympathetic vasoconstrictor response, but a preserved locally mediated response in the patients. In the head-up tilt table test, the patients had a significantly higher mean arterial blood pressure (MAP) compared with controls, probably due to a general increase in vascular resistance. There were no correlations between the ALS Severity Scores and blood flow changes, diastolic blood pressure or MAP. Our study supports previous results, but indicates abnormalities consistent with a solely centrally located sympathetic dysfunction in ALS, independent of the stage of the disease.

Initial sensorimotor and delayed autonomic neuropathy in acute thallium poisoning.

In a 27-year old male with acute thallium poisoning, signs of initially severe sensorimotor neuropathy with complete remission after two weeks were demonstrated. Signs of cardiovascular autonomic neuropathy were initially absent, but developed after a latency period of one week with marked improvement after seven months. Delayed autonomic neuropathy may be caused by a late affection of small unmyelinated autonomic nerve fibers.

Sympathetic vasoconstrictor reflexes in Parkinson's disease with autonomic dysfunction.

Centrally and locally elicited sympathetic vasoconstrictor responses were examined in 12 patients with symptoms and signs of cardiovascular autonomic dysfunction due to Parkinson's disease. The sympathetic reflex mechanisms were measured in skeletal muscle and subcutaneous tissue of the arm and leg using the 133-Xenon washout technique. This method allows differentiation between local and central sympathetic reflexes in different tissues. The results indicate an abolished centrally mediated vasoconstrictor response in skeletal muscle in the arm and a decreased response in skeletal muscle in the leg and in subcutaneous tissue. This is in agreement with an autonomic dysfunction located in the central nervous system. A possible spinal sympathetic reflex controlling blood flow in subcutaneous tissue and leg muscles is considered. The sympathetic vasoconstrictor responses in parkinsonian patients without autonomic failure were of normal magnitude and the responses were not affected by long-term levodopa treatment.

Sympathetic vasoconstrictor responses in multiple sclerosis with thermo-regulatory dysfunction.

Centrally and locally mediated sympathetic vasoconstrictor responses in skeletal muscle and subcutaneous tissue were studied in six patients with definite multiple sclerosis and severely affected thermoregulatory sweating. The purpose of the study was to evaluate vasomotor function in patients with pronounced thermoregulatory dysfunction and to differentiate between locally and centrally elicited vasomotor reflexes in two different tissues. The method used, the 133-Xenon washout technique, makes such a distinction possible. In spite of the severe sweating disturbances, we found centrally and locally mediated sympathetic vasomotor reflexes to be preserved in skeletal muscle and subcutaneous tissue. The results support the view that sudomotor and vasomotor functions are independently controlled. Previously described differences in sympathetic vasoconstrictor responses in skeletal muscle and subcutaneous tissue in several other neurological disorders are not present in patients with multiple sclerosis, based on our results.

Cognitive function and anticonvulsant therapy: effect of monotherapy in epilepsy.

INTRODUCTION: The effect of antiepileptic drugs (AED) on cognitive function was studied in 87 patients with epilepsy. MATERIAL AND METHODS: Group A: (n = 52) started AED treatment (carbamazepine, oxcarbazepine, sodium-valproate, phenobarbital or phenytoin). Group B: (n = 27) had AED monotherapy withdrawn (carbamazepine or sodium-valproate). Group C: (n = 8) was switched from phenytoin to carbamazepine monotherapy. The patients were tested before and 4 months after change of the treatment. RESULTS: In group A the test performances were in general unchanged. Patients who had their drug treatment withdrawn (group B) and the patients who were switched from phenytoin to carbamazepine (group C) improved in single tests. The predominant changes in performance seem to be due to practice effect. CONCLUSION: Cognitive functions are only minimally influenced by AEDs after short-term treatment whereas there is a slight improvement after discontinuation of long-term administration of carbamazepine and valproate. A lack of practice effect might be the first indicator of a negative effect of AED on cognitive function.

[Image transmission between hospitals. Technical and clinical testing of the equipment for digital image transmission between hospitals via the ordinary telephone network]. / Billedtransmission mellem sygehuse. Teknisk og klinisk afprøvning af apparatur til overførsel af digital billedinformation mellem sygehuse via det almindelige telefonnet.

A standard PC-based equipment--"Multiview Photophone"--for two-way image conference between hospitals by means of digital images transmitted through ordinary telephone lines was tested. The technical and visual quality of scanned and transmitted pictures proved to be satisfactory, and ease of handling the equipment and transmission times were acceptable. The clinical test was made by image conferences between a neurological department in a general hospital and a neurosurgical department in a university hospital. CT-scans concerning 39 patients in a prospective series, for whom specialist advice from the neurosurgical department was found necessary, were transmitted. Four of nine acute patients were saved an "unnecessary" transferral to the neurosurgical department. The 30 elective patients were all found to benefit from the two-way conferences, since the decision time was reduced and the quality of information given to the patients and their relatives was improved.

Oesophageal transit in patients with autonomic dysfunction. The effect of treatment with fludrocortisone.

Oesophageal function was examined by radionuclide transit measurements in 15 patients with severe autonomic deficiency and orthostatic hypothension and 23 healthy volunteers. Seven of the patients were re-examined after treatment for 3 weeks with fludrocortisone acetate (Florinef). Six patients and five control subjects were evaluated before and after i.v. administration of atropine. The mean transit time (MTT) was prolonged (P less than 0.007) and the residual activity increased (P = 0.038) in the patients compared with the control group. Prolonged MTT was associated with oesophageal symptoms. Treatment of orthostatic hypotension with fludrocortisone acetate significantly reduced MTT. Atropine increased MTT and residual activity. The increase in heart rate after atropine was correlated in the patients with MTT before treatment. The results demonstrate the frequent presence of impaired oesophageal function in patients with severe autonomic dysfunction, irrespective of aetiology. The impairment seems to be closely related to parasympathetic insufficiency. The improvement after fludrocortisone may suggest an influence of ion balance on oesophageal function in these patients.

A Fabry's disease heterozygote with a new mutation: biochemical, ultrastructural, and clinical investigations.

A Fabry heterozygote with early clinical manifestations of this X linked disorder is described. Her symptoms, including febrile attacks, arthralgia, abdominal pain, and neurological signs, were characteristic of Fabry's disease hemizygotes. The neurological findings were compatible with a brain stem infarction. The diagnosis was confirmed by the finding of low activities of alpha-galactosidase A (alpha-galA) in plasma, lymphocytes, and cultured fibroblasts, and by the observation of typical lamellar inclusions in the lysosomes of cultured fibroblasts. Increased levels of ceramide trihexoside were also found by TLC of urine sediment. The family history gave no indication of Fabry's disease in the patient's relatives, and biochemical and ultrastructural investigations of their cells were also normal. Our findings therefore suggest that the defective gene in the heterozygote has resulted from a new mutation.

The incidence of herniated disc and varicella zoster virus infection in lumboradicular syndrome.

121 patients suffering from lumboradicular syndrome were examined for the presence of varicella zoster virus (VZV) infection. Lumbar myelography was carried out on all. VZV-antibody determination in blood, as well as in spinal fluid, was by indirect ELISA. In 40% of cases lumbar myelography revealed no signs of a herniated disc; none had raised antibody titre in spinal fluid. VZV-antibody titre in blood indicated VZV infection in only 3.

Cardiovascular autonomic function in multiple sclerosis.

The autonomic nervous function of the cardiovascular system was investigated by non-invasive methods in 30 multiple sclerosis patients between 20 and 50 years of age. The results were compared to those of 30 healthy controls in the same age group. Minor abnormalities of parasympathetic and sympathetic function occurred. Heart rate variation at deep breathing was reduced and more than half of the patients had abnormal responses during an orthostatic procedure, mainly as an increased rise in heart rate. Decreased rise in blood pressure at sustained handgrip was also demonstrated. The abnormalities correlated poorly with other clinical signs and symptoms in the patients.

Conservatively treated patients with cerebral arteriovenous malformation: mental and physical outcome.

Twenty five patients with conservatively treated cerebral arteriovenous malformation were followed up for a mean of 10.6 years after diagnosis. The follow up included neuropsychological examination. Bleeding did not occur after the time of diagnosis. Three patients had moderate to severe neurological deficits, five had moderate to severe intellectual impairment. Nineteen had an unaffected occupational status. It is concluded that the outcome in conservatively treated patients may be no worse than in surgically treated patients.

Blood flow in skeletal muscle of tetraplegic man during postural changes.

Relative changes in blood flow and vascular resistance in arm and leg muscle during head-up tilt at 45 degrees were studied in eight patients with complete cervical spinal cord transection and in 13 healthy volunteers. Muscle blood flow was measured by the local 133Xe washout method. In forearm muscle kept at heart level blood flow remained constant in the tetraplegic patients during head-up tilt, in contrast to that seen in the normal subjects, where blood flow decreased by 30%. In the dependent leg muscle, head-up tilt caused a decrease in blood flow of 46% and 40% in the patients and normals, respectively. Abolition of the local veno-arteriolar axon reflex, by inducing local counter-pressure to prevent venous distension in the dependent leg muscle, reduced the decrease in blood flow to 24% and 23%, respectively. Thus, the vascular response to head-up tilt differed significantly in forearm muscle between the two groups, whereas no difference was seen in the leg muscle. The absence of the vasoconstrictor response in forearm muscle indicates that postural sympathetic reflexes to this region depend on sympathetic reflexes integrated in centres located rostrally to the spinal cord. The results further suggest that local veno-arteriolar axon reflexes as well as spinal reflexes contribute to the observed vasoconstriction in the leg muscle.

Decrease in beta-receptor density explaining the development of pindolol- and prenalterol-tolerance in orthostatic hypotension.

A 58-year-old woman with diabetic autonomic dysfunction was well treated for orthostatic hypotension with pindolol. After eight months however, symptoms recurred in spite of continued treatment with pindolol. Addition of prenalterol, a beta-blocking agent with very high intrinsic sympathomimetic activity, had a marked clinical effect on her orthostatic hypotension. Before treatment with prenalterol, stroke volume and left ventricular enddiastolic volume markedly decreased during tilt, as demonstrated by radionuclide angiography. After short-term prenalterol treatment, the orthostatic decreases of stroke volume and left ventricular end-diastolic volume were less pronounced. During continued prenalterol treatment, both symptoms and haemodynamic changes recurred in the erect position. Beta-receptor density in her lymphocytes decreased from elevated levels before prenalterol to subnormal levels, when the clinical effect had disappeared. The data suggest that the tolerance development to prenalterol may be explained by the decrease in beta-adrenergic receptor density.

Cardiac conduction disturbances during carbamazepine therapy.

3 cases of carbamazepine (CBZ)-induced Stokes-Adams attacks caused by intermittent total atrioventricular block, sino-atrial block with junctional escapade-rhytm and intermittent asystolia are reported. After cessation of CBZ treatment, the cardiac conduction disturbances disappeared. In 2 of the patients, the diagnosis was confirmed by resumption of treatment with CBZ after insertion of a demand pacemaker. If syncopes or changes in seizure-type occur in patients treated with CBZ, evaluation of cardiac conduction is recommended. Furthermore, it is recommended that cardiac function is evaluated before CBZ-treatment, especially in elderly patients.

Intravenous radionuclide angioscintigraphy and computer tomography in cerebral arteriovenous malformations.

In 25 patients with cerebral arteriovenous malformation (AVM) computer tomography (CT) was compared with dynamic and static intravenous radionuclide angioscintigraphy (99mTc-labelled red blood cells). The diagnosis was verified by arteriography performed 2-20 years prior to this study. Scintigrams and CT-scans were evaluated 'blindly' by independent observers after pooling of the patient studies with 20 and 20 control studies, respectively. Only images strictly characteristic of AVM were classified as positive. The nosographic sensitivity of both methods was about 70%, in a few patients they were supplementary. Neither CT nor scintigraphy were able to detect lesions of less than 2 cm diameter. The methods seem to be of equal and rather high specificity, and are both well suited as screening procedures. CT provides additional information as to other intracranial abnormalities. The screening method of first choice when AVM is suspected may be CT or angioscintigraphy, depending on availability of equipment and expertise.

Carbamazepine monotherapy in epileptic out-patients.

The effect and side-effects of carbamazepine monotherapy have been studied retrospectively in 280 epileptic out-patients. The majority of these patients suffered from grand mal epilepsy, partial complex seizures or a combination of both seizure types. Side-effects, in 63% exanthema, led to withdrawal in 10% of the patients. Satisfactory effect of treatment, defined as reduction of seizure frequency by at least 75% or unchanged satisfactory seizure control, was seen in 76% of patients, most commonly those with grand mal. Deterioration was observed in 9% of patients. These results were independent of whether or not carbamazepine monotherapy was drug of first choice. Serum concentrations of carbamazepine, measured in 236 patients, were found to be within the therapeutic range in 72% and above the range in 22%. Our results, which we consider to represent 'normal daily life in an epilepsy out-patient clinic', are comparable with those of controlled prospective studies, but there was a considerably higher frequency of withdrawal due to side-effects.

Treatment of diabetic orthostatic hypotension with pindolol.

The hemodynamic variables, plasma noradrenaline and plasma renin concentrations were studied in a 57-year-old female with insulin-dependent diabetes of long-standing and orthostatic hypotension. For 6 months she had been bedridden because of severe orthostatic symptoms. Reflex responses in the heart rate and blood pressure during the Valsalva manoeuvre as well as beat-to-beat variations in heart rate were absent. Plasma noradrenaline concentrations were subnormal both in the supine and upright positions. After treatment with Pindolol 15 mg/day the patient was able to walk around and lead an almost normal life. The orthostatic symptoms recurred after withdrawal of therapy and disappeared on resumption of therapy. Arterial blood pressure measured intra-arterially decreased less in the up-right position during treatment with pindolol compared to that in the untreated condition. The heart rate did not change during treatment with Pindolol. Our findings suggest that Pindolol may be an important drug in the treatment of diabetic orthostatic hypotension.