Cerebrovascular complications after primary varicella-zoster infection.
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Adult↗
Biomedical subjects
L Ketonen
Publications and source records attributed to L Ketonen.
Brain imaging in human immunodeficiency virus infection.
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AIDS Dementia Complex↗
Osseous and muscular changes after vertical ramus osteotomy. A magnetic resonance imaging study.
Magnetic resonance (MR) imaging was performed about 2 years after vertical ramus osteotomy of 10 patients to study changes in the mandibular condyle, cortical and cancellous bone of the proximal fragment, and muscles of mastication. MR imaging observations of the surgically treated patients were compared with findings in 10 asymptomatic untreated control subjects. The results showed that the MR appearance of bone marrow of the mandibular condyle was normal in all patients and in all control subjects. No MR evidence of avascular necrosis of the mandibular condyle was found. MR imaging artifacts from microscopic metallic particles were seen in all surgically treated regions. Thickening of the buccal and lingual cortical bone with narrowing of the bone marrow space was seen bilaterally in eight patients and unilaterally in two patients. Slight medial tipping of the mandibular condyle was seen unilaterally in two patients. Atrophic changes with decreased muscle volume and fatty replacement of muscle tissue was seen unilaterally in eight patients. None of these alterations were seen in the control subjects. MR imaging appears to be an excellent method to study morphologic changes of the muscles of mastication and osseous fragments after orthognathic surgery of the mandible. Thickening of the cortical bone and narrowing of the bone marrow space of the proximal fragment was frequently seen after vertical ramus osteotomy of the mandible and most likely represents remodeling associated with normal healing.
Adolescent↗
Manic syndrome in AIDS.
A manic syndrome in eight patients with AIDS is described. On the basis of clinical, neuropsychological, laboratory, magnetic resonance imaging, and epidemiological evidence, the authors suggest that the manic syndrome was secondary to HIV infection. The patients also developed concomitant cognitive impairment.
AIDS Dementia Complex↗
Magnetic resonance imaging findings in HIV cognitive impairment.
Atrophy and white matter changes seen on magnetic resonance imaging scans have been observed in association with the acquired immunodeficiency syndrome dementia complex, but these appear to be late findings relative to clinical expression. We report a new magnetic resonance imaging observation in patients with early cognitive impairment due to human immunodeficiency virus infection. Fifty-two patients had a total of 86 magnetic resonance imaging scans during the study period. All scans were obtained with a 1.5-T system. The proton density spin echo (repetition time of 2000 milliseconds and echo delay time of 30 milliseconds) study demonstrated high-signal lesions in the region of the splenium of the corpus callosum and in the crura of the fornices. The lesions demonstrated no contrast enhancement with gadopentate dimeglumine. Pathological examination was performed in five patients. The fornix-subcallosal abnormality may be related to the memory dysfunction in patients with human immunodeficiency virus-related cognitive impairment.
Adult↗
Muscle-eye-brain disease and Walker-Warburg syndrome.
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Brain↗
MS and SLE in twins of successive generations.
During a nationwide twin study on multiple sclerosis (MS) in Finland a dizygotic pair discordant for MS was found. The affected co-twin had dizygotic twin daughters. The affected co-twin of the second generation had systemic lupus erythematosus (SLE). Both pairs were thoroughly examined. No evidence of CNS involvement in the healthy co-twins was found. In pairwise comparisons, virus-specific IgG antibodies to measles and mumps were significantly increased in the MS patient whereas the same was true for rubella in the SLE patient. Both MS and SLE patient expressed HLA alleles most often found to be associated with these disorders. Reversed CD4/CD8 ratios were observed in both MS and SLE patient. No difference in interleukin-2 receptor expression were found but gamma-interferon secretion in the MS patient showed marked increase whereas that of the SLE patient was of the same magnitude as in the healthy members. A different triggering stimulus rather than the dissimilarity in the immunogenetic predisposition may be decisive as to whether or not they develop MS or SLE.
Adult↗
White matter low attenuation on CT in Alzheimer's disease.
White matter low attenuation (WMLA) was seen on CT in 19.7% of 61 patients with probable Alzheimer's disease. Presence of WMLA was associated with higher age, more severe degree of dementia, and increased CSF/serum albumin ratio, but not with cardiovascular disorders. WMLA on CT might be related to minor vascular events, or Alzheimer patients with WMLA could even constitute their own subtype.
Aged↗
Muscle-eye-brain disease (MEB)
Clinical features of a rare congenital myopathy, muscle-eye-brain (MEB) disease, are described in 19 patients. The pedigree data suggest an autosomal recessive inheritance. The patients presented with congenital hypotonia and muscle weakness. Serum CK was elevated, EMG was myopathic and muscle biopsy showed slight or moderate changes compatible with muscular dystrophy. Ophthalmological findings included severe visual failure and uncontrolled eye movements associated with severe myopia. The flash VEPs were exceptionally high, whereas non-corneal ERG was unrecordable. The EEG showed progressive abnormalities after the age of 6 months. Psychomotor development was slow during the first years of life, and mental retardation was severe. Most patients began to deteriorate around age 5 years. This change included spasticity and joint contractures. CT scans showed ventricular dilatations and abnormally low white matter density in several patients. Spasticity, high VEPs and ocular manifestations differentiate MEB from the Fukuyama type congenital muscular dystrophy.
Adolescent↗
Reduced-bandwidth MR imaging of the head at 1.5 T1.
A decrease in the magnetic resonance (MR) imaging bandwidth can be used to increase the signal-to-noise ratio (S/N) at constant imaging time or to maintain the S/N for reduction of imaging time. The effect of bandwidth reduction from the default value of 16 kHz to 8 kHz was evaluated prospectively in 50 patients referred for MR imaging of the head. On intermediate (2,000/30 [repetition time msec/echo time msec]) and more T2-weighted (2,000/90) studies, there were no definite missed diagnoses and no diagnostically important changes in lesion characteristics when the reduced-bandwidth technique was used to obtain half- or quarter-time studies, excluding differences attributable to unintentional changes in patient position between image acquisitions. Chemical shift misregistration artifacts associated with reduced bandwidth are easily recognized with experience and do not interfere with diagnosis, as the artifacts occur in characteristic locations and diminish in most anatomic locations with increasing echo time. This study suggests the feasibility of reduced-bandwidth techniques in clinical MR imaging of the head at high field strength to achieve an increased S/N, to decrease imaging time, or to obtain images in additional projections.
Brain↗
Genetic susceptibility to multiple sclerosis. A co-twin study of a nationwide series.
The problems of differentiation between environmental and genetic influences on the development of multiple sclerosis are well known. Twin studies may provide valuable information on this question. However, most published twin series are selected and no through clinical twin studies based on epidemiologic series have been carried out. In this study, all available same-sex twin pairs with clinically definite multiple sclerosis derived from the Finnish Twin Cohort of 15815 pairs were studied by clinical evaluation, magnetic resonance imaging, and visual and auditory evoked responses. The mean length of follow-up of the pairs after the onset of symptoms of multiple sclerosis was 20 years. Two of the seven monozygotic pairs were concordant; one was definitely so, and in the other, the co-twin of the index case had, in addition to clinical findings, white matter changes suggestive of multiple sclerosis in magnetic resonance imaging and abnormal visual evoked responses. All six dizygotic pairs were discordant. The frequency of the HLA antigen DR2 in probands (69%) was significantly increased, but the distribution among the healthy subjects and patients showed nonsignificant differences. The results indicate a genetic influence on the susceptibility to multiple sclerosis, although still unknown genetic determinants are possible involved.
Adult↗
A follow-up study of very low field MRI findings and clinical course in multiple sclerosis.
Seventy-three consecutive patients with definite multiple sclerosis (MS) were examined with very low field (0.17 and 0.02 tesla) magnetic resonance imaging (MRI) of the brain. Fifty-seven patients were examined a second time after 6 months, 41 patients a third time after 1 year, and 25 patients a fourth time after 2 years. The initial finding was abnormal in 57/73 patients (78%). The number of lesions increased with age, duration of disease, and increasing disability. Plaques were more numerous in progressive than in remitting MS. Of the patients with abnormal MRI 65% had more than 3 lesions, and in 82% lesions were smaller than 2.5 cm in diameter. After follow-ups of 1 year and 2 years the size of MRI lesions remained unchanged in 55% and 64%, respectively. Unchanged plaque numbers were found in 72% and 60%. Unchanged MRI was most common among patients with remitting MS who were in a stable phase. Decrease in size and disappearance of plaques correlated well with clinical remissions. Increase in size was rare even during relapses. New plaques could appear during all phases of clinical course although they reflected better a relapse of remitting or progressive disease.
Adult↗
Fatal encephalitis caused by a bat-borne rabies-related virus. Clinical findings.
The clinical findings are described in the first reported European case of fatal encephalitis of bat origin caused by a rabies-related virus. A bat zoologist developed the symptoms of rabies 51 days after his last exposure to a bat bite. The clinical disease of 23 days duration was a combination of the paralytic and 'furious' forms of rabies. Serial BAEP and EEG recordings, CT and MR scans of the brain, as well as CSF findings, demonstrated severe ascending destruction of the brain. An unusual progression from isolated brainstem death to cortical brain death occurred. Neuropathologically, the brain showed severe lytic changes. The presence of rabies-related virus antigens in brain smears was shown using a panel of fluorescent antibodies. The virus was inoculated into and isolated from suckling mice. The virus had a close resemblance to European bat rabies isolates, which belong to the group of rabies-related viruses. Of particular concern is whether the virus can spread from bats to terrestrial animals and whether the European type of bat rabies constitutes a danger to man.
Adult↗
The value of CT and very low field MRI in the etiological diagnosis of dizziness.
A total of 79 dizziness patients were examined by either computed tomography (CT), or very low field magnetic resonance imaging (MRI), or both. In most cases, the patients were selected for the neuroimaging because preliminary clinical examination had suggested central nervous system (CNS) involvement. Abnormal CT or MRI findings with probable clinical relevance to the etiology of dizziness were obtained in 34%. The most common abnormalities were atrophy, infarction, and demyelination.; 29% of the CT scans and 40% of the MRI showed relevant abnormalities. The present results emphasize the diagnostic usefulness of head CT and MRI when dizziness of CNS etiology is suspected.
Adult↗
EEG in the differential diagnosis between Alzheimer's disease and vascular dementia.
Demented patients with Alzheimer's disease (AD) (n = 67), multi-infarct dementia (MID) (n = 77) and probable vascular dementia (PVD) (n = 45) were studied with electroencephalography (EEG). All patients underwent a routine EEG examination and quantitative EEG was recorded from 14 patients with AD, 20 with MID, and 12 with PVD. The patient groups did not differ in regard to sex, age, education, or degree of dementia. Diffuse abnormality of EEG increased in AD, while driving response to photic stimulation and the mean frequency of background activity decreased in all groups with increasing degree of dementia. In quantitative EEG, the percentage of alpha power decreased and those of theta and delta power increased relative to the degree of dementia. Focal abnormalities, and irritative (spikes and/or sharp waves) and slow wave paroxysms were more common in MID than in AD. Patients with different types of dementia did not differ significantly in regard to diffuse abnormality, occurrence of driving response, mean background frequency, or parameters of quantitative EEG. The mean frequency of background activity and the degree of diffuse abnormality correlated with central and cortical atrophy, white matter low attenuation seen on computed tomography, and with neuropsychological findings.
Adult↗
Magnetic resonance imaging, evoked responses and cerebrospinal fluid findings in a follow-up study of children with optic neuritis.
Fourteen patients with previous optic neuritis (ON) in childhood were examined by magnetic resonance (MR) imaging from two months to 14 years after the onset of symptoms. Five patients had a single monosymptomatic course of ON but 7 developed multiple sclerosis (MS); 2 had another demyelinating disease. Eight patients had high signal intensity areas in the T2 weighted images compatible with MS plaques in MR scan; 2 with monosymptomatic ON, 5 with MS and one with another demyelinating disease. The plaques were periventricular or in the optic radiation. The plaques could already be seen during the first symptoms of ON. All 7 MS patients had abnormal visual evoked response, 3/4 abnormal somatosensory evoked response and 5/6 intrathecal immunoglobulin production, when examined at onset of optic neuritis or at follow-up. All patients except one, with lesions in MR, had either oligoclonal CSF antibodies or Dr2 HLA antigen. We suggest that MR is a very sensitive test showing MR abnormalities in children with ON. It is an important tool in the early assessment of MS.
Adolescent↗
Preliminary experience of magnetic resonance imaging in neurosarcoidosis.
Twelve MR scans performed on seven patients with neurosarcoidosis are presented. The most common abnormalities were ventricular enlargement (four patients) and diffuse periventricular white matter changes (three patients). Infarcts were seen in three patients and mass lesion in one. The lesions were seen in both T1 and T2 weighted images. The results are compared with CT findings. MRI seems to be more sensitive than CT in detecting white matter changes and infarcts. Ventricular enlargement and granulomas were equally well seen with both modalities.
Adult↗
Evaluation of central nervous system involvement in uncomplicated optic neuritis after prolonged follow-up.
Magnetic resonance imaging (MRI), multimodal evoked responses (ER) and HLA antigens were examined in 10 patients with idiopathic acute optic neuritis (ON) without any clinical symptoms or signs of multiple sclerosis (MS) during 9-14 years. In MRI, abnormalities compatible with MS were seen in 4 patients. In spite of clinically unilateral ON, a bilateral abnormality in visual evoked responses (VER) was seen in 3 of 9 cases. Brain stem auditory evoked responses (BAER) were normal in all cases, short latency somatosensory evoked response (SER) in all but one. The cerebrospinal fluid at time of ON showed signs of demyelination in one case only. The frequency of HLA antigens DR2 (78%) and B18 (40%) was significantly increased in comparison to healthy controls. MRI seems to be the most sensitive method in the detection of cerebral lesions of MS, especially in mild or asymptomatic forms of the disease. The present techniques are, however, mostly unable to demonstrate optic nerve lesions which more reliably can be evaluated by VERs. The question whether idiopathic ON represents a form of MS solely, cannot be resolved.
Adult↗