This study investigated the incidence of peripheral hearing loss in sickle cell anemia and the possibility of central auditory nervous system involvement. Nine Black subjects with sickle cell disease and nine with normal hemoglobin were administered an auditory test battery. There appeared to be no correlation between number of crisis episodes, duration of symptoms, severity of symptoms, and audiologic manifestations. Acoustic reflex testing suggested the possibility of "aired neural function in the sickle cell group. Whether impaired function was due to peripheral VIIIth nerve or to central brain stem involvement could not be determined. Results of the central auditory test battery suggested the possibility of impaired or reduced central auditory function in subjects with sickle cell anemia.

In einer retrospektiven Studie wurden 119 Patienten mit Hörsturz auf die Aussagefähigkeit der Umfelddiagnostik bezüglich einer sekundären Prävention beim Hörsturz untersucht. Außerdem sollte anhand der vorliegenden Analyse die Hypothese überprüft werden, dass Störungen im Innenohr durch Veränderungen der Halswirbelsäule oder des Kardiovaskulären- und Zentralnervensystems hervorgerufen werden können. 57 % (68/119) der computertomographisch untersuchten Patienten waren neurologisch unauffällig, und 45,6 % der Patienten hatten physiologische Halswirbelsäulen-Veränderungen, die auch in der Normalbevölkerung festzustellen sind. Im internistischen Bereich wurden die häufigsten kardiovaskulären Risikofaktoren und die Wandbeschaffenheit der Halsgefäße auf hämodynamische Stenosen ausgewertet. Bei der doppler-sonographischen Untersuchung der Karotisgefäße fanden sich keine Hinweise auf hämodynamisch wirksame Stenosen. Aufgrund dieses Ergebnisses sollte die doppler-sonografische-Untersuchung der Karotisgefäße nicht obligat im Rahmen der Umfelddiagnostik durchgeführt werden. Im untersuchten Patientenkollektiv lassen sich folgende Risikofaktoren (RF) erheben: Hypertonie (19 %), Hypercholesterinämie (28 %), Hypertriglyceridämie (20 %), Adipositas (31 %), Nikotinabusus (26 %) und Diabetes mellitus (3,3 %). Dabei betrug der Anteil an keinem oder einem RF Belasteten 62 %, zwei bis drei RF besaßen 33 % der Untersuchten. 5 % der Hörsturzpatienten hatten vier bis fünf RF. Im Risikofaktorprofil zeigt sich im Vergleich der Hörsturzgruppe mit der Normalbevölkerung eine vermehrte Prävalenz für Cholesterin und Adipositas. Die restlichen Risikofaktoren haben ein geringeres oder gleich häufiges Vorkommen wie in einer unabhängigen Bevölkerungsuntersuchung. In Hinblick auf die Lebensqualität der Patienten und in einer Zeit von immer knapper werdenden Finanzressourcen ist ein rationaler Einsatz der verschiedenen Verfahren in der Umfelddiagnostik beim Hörsturz zu fordern. Auf kostenintensive und den Patienten belastende Untersuchungen, wie z.B. das HWS-Röntgen oder die interdisziplinären Konsiliar untersuchungen kann nach der vorliegenden Studie verzichtet werden. Es sollte zwischen der routinemäßigen Umfelddiagnostik und der gezielten Diagnostik unterschieden werden. Spezielle konsiliarische Untersuchungen sollten nur bei anamnestischem Hinweis erfolgen. / A retrospective study was conducted with involvement of 119 patients with sudden deafness who were investigated for the amount of information potentially obtainable from environmental diagnostics with regard to secondary prevention of sudden deafness. The analytical results were additionally used to check on the hypothesis according to which disorders to the inner ear might be caused by lesions to the cervical spine or cardiovascular and central nervous systems. The average age of the patients was 47.6 + 6.5 years (range: 20-87). Females accounted for 27 % (32/119) and males for 73 % (87/119). Computed tomography failed to reveal any neurological findings in 57 % (68/119), while 45.6 % of the patients exhibited physiological alterations of the cervical spine as were more or less common in the general population. In internist diagnosis, emphasis was laid on the most common cardiovascular risk factors and on the condition of cervical vessel walls. No signs indicative of haemodynamically relevant stenoses were recorded by Doppler sonography of carotid vessels. The following risk factors may be defined on the basis of results: hypertension (19 %), hypercholesterolaemia (28 %), adiposity (31 %), hypertriglyceridaemia (20 %), nicotine abuse (26 %) and diabetes mellitus (3.3 %). Not more than one risk factor was identified in the overwhelming majority of all patients (62 %), two or three risk factors in 33 % and more than three in 5 %. Higher prevalence of cholesterol and adiposity were the only factors by which patients differed from the general population. High-economy use of procedures in environmental diagnostics of sudden deafness has to be demanded to improve patients' quality of life and to cope with persistent shrinkage of financial resources. This study seems to suggest that cost-intensive and stressful examinations can be abandoned, such as X-ray of cervical spine, Doppler sonography or involvement of interdisciplinary consultant bodies. Routine environmental diagnostics should be replaced by targeted diagnostics. Specialised imaging and consultant-based investigations should not be conducted unless otherwise suggested by case history.

The spotted fever rickettsia, Rickettsia helvetica, is an endemic tick-borne bacteria in Sweden. It causes infections in humans, manifested as aneruptive fever, headache, arthralgia and myalgia, and sometimes an inoculation eschar or a rash. There have also been two known cases of human infections with R. felis in Sweden. The present thesis starts by investigating dispersal of ticks and Rickettsia spp. by migrating birds flying from Africa to Europe. Almost 15,000 birds were searched and 734 ticks collected, mainly of the species Hyalomma marginatum complex. Almost half (48%) of the ticks were infected with Rickettsia spp., 96% of which was R. aeschlimannii, the remaining R. africae and undefined species. The next study focused on questing ticks over a large area in Sweden and determining the prevalence of Rickettsia spp., Anaplasma spp. and Coxiella burnetii. Rickettsia spp. was found in 9.5-9.6% of the ticks and A. phagocytophilum in 0.7%; no C. burnetii was found. The last three papers in the thesis focused on the clinical presentation of rickettsiosis, the symptoms associated with the infection in general and particularly in patients with neurological complications. A tick-exposed population in Sweden was investigated to gain a better understanding of symptoms due to rickettsioses, also in relation to co-infections with other tick-borne bacteria. Based on symptoms, it was not possible to distinguish what pathogen caused the infections. Most patients had erythema migrans, some had serological reactions to Rickettsia spp., Borrelia spp. or co-infections by Rickettsia spp., Borrelia spp. and/or Anaplasma spp. In the fourth and fifth papers, we found associations between antibodies against Rickettsia spp. and sudden deafness (in 10-24% of patients) and facial nerve paralysis (in 8.3-25% of patients). In three patients R. felis was detected in the cerebrospinal fluids.    Briefly, the thesis helps to clarify our knowledge about tick dispersal, shows a narrower prevalence estimate of Rickettsia spp. in Swedish ticks, and illuminates symptoms of rickettsioses and co-infections with other tick-borne infections. It also shows that presence of erythema migrans may be explained by more than Lyme disease and indicates a possible association between rickettsiosis and sudden deafness and facial nerve paralysis.