[Progressive multifocal encephalopathy in a LED patient]. / SLE-potilaan etenevä multifokaalinen enkefalopatia.

Progressive multifocal encephalopathy (PML) is a rare demyelinating disease of the central nervous system, caused by the reactivation of the JC virus in the body during immunosuppression. The use of monoclonal antibodies predisposes to PML, and the epidemiology of the disease has changed. We describe the first PML published from Finland and associated with rituximab treatment in a LED patient.

[Tongue abscess]. / Kielipaise.

Tongue abscess is a rare and sometimes life-threatening condition, as swelling of the tongue may rapidly occlude the airways. In a patient described by us swelling of the tongue was found in MR imaging to be caused by an abscess of the anterior part of the tongue, extending to the floor of the mouth, beside the submandibular gland. It was only after recanalization of the compartmentalized abscess of the tongue and removal of the salivary gland that the patient recovered.

[Gliomatosis cerebri as cause of neuropsychiatric symptoms]. / Gliomatosis cerebri neuropsykiatristen oireiden syynä.

Gliomatosis cerebri (GC) is a rare cancer of the central nervous system, having already penetrated into various areas of the central nervous system upon becoming manifest. In tissue specimens the histopathologic picture of the tumor appears similar to that seen in diffuse gliomas at different stages of disease. Typical MRI findings in GC include diffuse increases in signal intensity in the brain, and indistinct gray-white matter demarcation in T2-weighted images. Surgical treatment is usually not possible. We describe a patient, in whom CG turned eventually out to be the cause of severe neuropsychiatric symptoms.

[Myelitis following vaccination against tick-borne encephalitis]. / Puutiaisaivokuumerokotuksen jälkeinen myeliitti.

Tick-borne encephalitis is a significant concern in endemic regions, and in rare cases it may even be fatal. There is no specific treatment for the disease. Vaccines from two manufacturers are available against tick-borne encephalitis, both considered effective and safe. Severe adverse effects due to tick-borne encephalitis vaccine are rare. We describe the first severe myelitis detected in Finland following vaccination against tick-borne encephalitis.

Tick-borne encephalitis virus in wild rodents in winter, Finland, 2008-2009.

Rodents might maintain tick-borne encephalitis virus (TBEV) in nature through latent persistent infections. During 2 subsequent winters, 2008 and 2009, in Finland, we detected RNA of European and Siberian subtypes of TBEV in Microtus agrestis and Myodes glareolus voles, respectively. Persistence in rodent reservoirs may contribute to virus overwintering.

[Fatal tick-borne encephalitis]. / Kuolemaan johtanut puutiaisaivokuume.

The number of cases with tick-borne encephalitis in Europe has increased particularly in the 1990's, and new regions have become endemic. Ixodes persulcatus, i.e. the taiga tick, is found on the west coast of Finland along the Närpiö-Simo axis. This tick has not been encountered in other parts of Western Europe. In Kokkola archipelago it transmits the Siberian subtype of tick-borne encephalitis virus. We describe the first and fatal case of tick-borne encephalitis transmitted by the "taiga tick" in Finland.

Pulsatile tinnitus as a symptom of cervicocephalic arterial dissection.

The aim of this study was to investigate pulsatile tinnitus as a presenting symptom in cervicocephalic arterial dissection (CCAD). Of the 136 consecutive patients with confirmed CCAD, 16 presented with pulsatile tinnitus. On admission 10 patients presented with subjective tinnitus and five with objective tinnitus, tinnitus being the only presenting symptom in one case. In one further case with bilateral ICA dissection (ICAD) subjective tinnitus appeared three months after the initial symptoms of arterial dissection, despite a contralateral cervical bruit being evident on admission. Thirteen patients presented with headache or neck pain. Ischaemic symptoms were detected in six and Horner's syndrome in four patients. Vertigo and dysgeusia were reported in two patients each. Arterial dissection involved unilateral ICA in 11, bilateral ICA in two, unilateral vertebral artery (VA) in two and bilateral ICA and bilateral VA in one patient. In angiography the most common finding was irregular stenosis, and the majority of these abnormalities normalized during follow-up. To avoid delay in diagnosis a high index of suspicion and early angiography (digital subtraction or magnetic resonance angiography) are warranted.

Shrapnell's membrane in a mammal exposed to extreme pressure variations: morphological and radiological observations in the hooded seal.

The function of Shrapnell's membrane (pars flaccida; PF) in middle-ear mechanics is still an enigma, though numerous proposals have been put forward, e.g. protection of pars tensa, equalizing of middle-ear pressure, sound transmission, and the site of origin of otitis media. In this study the PF was studied in a mammal (the hooded seal) which exposes itself to extreme pressure differences (from 1 to 100 atmospheres) when diving. Formaldehyde-fixed temporal bones obtained from newborn, one-year-old, and adult seals (three of each) were cleansed and decalcified in 10 per cent EDTA. The lateral wall of the middle-ear cavity, including the whole tympanic membrane with its bony surroundings, was then excised and photodocumented. Thin sections were cut parallel with, and perpendicular to, the handle of the malleus, stained with haematoxylin-eosin, toluidine blue or Giemsa stain and examined under a light microscope. One seal head was subjected to high resolution computerized tomography (HRCT) before sectioning. The PF was observed to be a narrow fissure measuring a maximum of 0.8 mm between processus brevis of the malleus and the notch of Rivinus in pars squamosa (pars tensa diameter 10-12 mm). It seems unlikely that the PF of the hooded seal participates in pressure equalization in the middle ear. The main function of the lateral wall of the attic, including the minimal PF, appears to be to protect the middle-ear ossicles and allow movement of the malleus.