Esko Kinnunen

Infections of the central nervous system of suspected viral origin: a collaborative study from Finland.

We studied 3231 patients with acute central nervous system (CNS) symptoms of suspected viral origin to elucidate the current etiologic spectrum. In 46% of the cases, a viral finding was observed. Varicella-zoster virus (VZV) was the main agent associated with encephalitis, as well as meningitis and myelitis. VZV comprised 29% of all confirmed or probable etiologic agents. Herpes simplex virus (HSV) and enteroviruses accounted 11% each, and influenza A virus 7%. VZV seems to have achieved a major role in viral infections of CNS. In encephalitis in our population, VZV is clearly more commonly associated with these neurological diseases than HSV. The increase in VZV findings may in part be a pseudophenomenon due to improved diagnostic methods, however, a true increase may have occurred and the pathogenetic mechanisms behind this should be elucidated.

Incidence of Guillain‐Barré syndrome during a nationwide oral poliovirus vaccine campaign

Concomitant with a nationwide oral poliovirus vaccine (OPV) campaign in Finland in 1985, an unexpected rise in the number of patients hospitalized with the Guillain-Barré syndrome (GBS) occurred. An analysis based on hospital records covering a population of 1.17 million and 6 years revealed a significantly increased incidence of GBS coinciding with the OPV campaign. We carefully examined 10 cases with onset of GBS within 10 weeks after immunization. Only 4 patients could recall recent symptomatic infection, and we found no specific agent in these cases. Our study suggests that live-attenuated polioviruses may, like other infectious viruses, sometimes trigger the GBS.

Multiple sclerosis in a nationwide series of twins

A nation wide Finnish Twin Cohort was linked with sickness insurance and hospital discharge registers on the basis of the unique identification number assigned to each Finnish citizen. The study series consisted of 4,063 monozygotic (MZ) and 9,001 dizygotic (DZ) same-sexed twin pairs born before 1958 and alive in 1981. Altogether, 22 subjects representing 11 MZ pairs and 10 DZ pairs showed clinically definite multiple sclerosis (MS). In one MZ pair both members had the disease. The frequency of MS among DZ twins corresponded to the figure in the Finnish population, but the prevalence was higher in MZ twins than in DZ twins.

Multiple sclerosis, in Finland Evidence of increasing frequency and uneven geographic distribution

For the present incidence study of multiple sclerosis (MS) in Finland, reliable data since 1964 were available. The mean annual incidence rate of MS was significantly higher in the western part (3.3 per 100,000) than in the southern part of the country (2.2 per 100,000). The mean annual incidence for all MS patients was highest during the second of the three 5-year periods from 1964 to 1978. However, the incidence for women in the western part increased also thereafter. At the same time, the female-to-male incidence ratio changed from 1.0 to 2.2. The results confirmed an uneven distribution with a stable cluster of MS in the western part of the country.

The incidence of optic neuritis and its prognosis for multiple sclerosis

ABSTRACT An incidence study of idiopathic optic neuritis (ON) was carried out in 2 geographic areas of Finland for the 9‐year period 1970 to 1978. The southern province of Uusimaa composes a medium‐risk and the western province of Vaasa a high‐risk area for multiple sclerosis (MS). The risk for subsequent MS was determined.

Guillain‐Barré syndrome: Quantitative measurement of plasma exchange therapy

A prospective, controlled study with quantitative measurement of hand muscle-force for plasma exchange treatment in acute Guillain-Barré polyradiculitis was done. Of the 29 patients with severe symptoms, every second patient was selected to the plasma exchange group and all others to the control group. The muscle forces increased and CSF protein decreased significantly more in the plasma exchange group than in the control group, but there were no differences in hospitalization or recovery periods.

Myasthenia gravis associated with multiple sclerosis: Epidemiological survey and immunological findings

Patient registers on myasthenia gravis (94 patients) and multiple sclerosis (991 patients) from a population of 1.5 million were reviewed to find patients with both diseases. Seven potential candidates were found, but both diagnoses were confirmed in 2 women only. The first patient had also iritis, the second patient had, besides MG and MS, bronchial asthma and polyarthritis. Both neurological diseases had a relatively mild clinical course. Thymectomy relieved MG symptoms in both patients. Cerebrospinal fluid studies during the follow-up indicated immunoactivation within the central nervous system. Changes in cellular immunity were also noted. The HLA types were different. The combination of these two diseases appears to be more common than expected.

Localized outbreak of enteroviral meningitis in adults

During a thorough surveillance of viral infections of the central nervous system an outbreak of aseptic meningitis was discovered in the western part of Finland in late 1985. The 21 diseased young adults were carefully studied by different virological methods. A presumed viral etiology, in all cases of enteroviral origin, was found in 16 of 20 (80%) with adequate specimens. Four different enteroviruses were associated with this episode; in 9 cases the presumed etiological agent was echovirus 5, while coxsackie B5, echo 25 and echo 17 viruses appeared to be responsible for 4, 2 and 1 case, respectively. Sensitivity of different diagnostic methods as regards detection of the echovirus 5 infections was in order: increase of type‐specific neutralizing serum antibodies, isolation of virus from faeces, isolation from throat and group diagnosis by demonstrdling an increase in complement‐fixing antibodies to coxsackie BS virus antigen.

Increased occurrence of free immunoglobulin light chains in cerebrospinal fluid and serum in human immunodeficiency virus-1 infection

The presence of free immunoglobulin light chains (FLCs) in the cerebrospinal fluid (CSF) and sera of patients with human immunodeficiency virus-1 (HIV-1) infection, multiple sclerosis (MS), and neurologically healthy control individuals was investigated by paying special attention to ensure that only truly free light chains would be detected. The FLCs were extracted by specifically binding them to Sepharose-coupled anti-FLC monoclonal antibodies, and thereafter they were electrophoresed and immunoblotted with monoclonal antibodies to both light chain (LC) isotypes. A frequent occurrence of kappa and lambda FLCs was found in both CSF and sera of HIV-1 infected patients. In HIV-1 infection and in MS, the frequency of FLCs of the CSF was equal. In healthy controls, only occasional weak FLCs were observed in either CSF or serum. FLC bands of the CSF from patients with HIV-1 infection tended to be more intensive than those of the appropriately diluted sera. Both intrathecal synthesis of FLCs and their transudation from sera through the impaired blood-brain barrier (BBB) may contribute to this. Increasing severity of general HIV-1 infection was accompanied by an increase of FLC intensity in sera. A qualitative demonstration of FLC in the CSF may be meaningful only in the absence of altered BBB function.

Patient satisfaction with switching to Stalevo: an open‐label evaluation in PD patients experiencing wearing‐off (Simcom Study)

Objectives and methods –  This study investigated the ease with which 52 Parkinsons disease patients already receiving adjunct entacapone to traditional levodopa were switched to Stalevo® (levodopa/carbidopa/entacapone).