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J Pyhtinen

Publications and source records attributed to J Pyhtinen.

At least 19 recordsLinked to original sources
PubMed2006

A 3-year clinical follow-up of adult patients with 3243A>G in mitochondrial DNA.

OBJECTIVE: To follow the clinical course of patients with the mitochondrial DNA mutation 3243A>G for 3 years. METHODS: Thirty-three adult patients with the 3243A>G mutation entered a 3-year follow-up study. They were clinically evaluated annually, audiometry was performed, and samples were drawn for the analysis of blood chemistry and mutation heteroplasmy in leukocytes. Holter recording was performed three times during the follow-up and echocardiography, neuropsychological assessment, and quantitative EEG and brain imaging conducted at entry and after 3 years. RESULTS: The incidence of new neurologic events was low during the 3-year follow-up. Sensorineural hearing impairment (SNHI) progressed, left ventricular wall thickness increased, mean alpha frequency in the occipital and parietal regions decreased, and the severity of disease index (modified Rankin score) progressed significantly. The rate of SNHI progression correlated with mutation heteroplasmy in muscle. The increase in left ventricular wall thickness was seen almost exclusively in diabetic patients. Seven patients died during the follow-up, and they were generally more severely affected than those who survived. CONCLUSIONS: Significant changes in the severity of disease, sensorineural hearing impairment, left ventricular hypertrophy, and quantitative EEG were seen in adult patients with 3243A>G during the 3-year follow-up.

Adult↗
PubMed2006

Potential of diffusion imaging in brain tumors: a review.

Diffusion magnetic resonance imaging (MRI) is a method for quantifying the microscopic random motion of water molecules in tissues. Diffusion imaging provides indirect structural information of a kind not available on basic MRI sequences of many pathological conditions. Lately, especially brain tumors have been under active investigation, with numerous papers already published, and their number continues to increase. This review summarizes the heterogeneous and complex research data on diffusion imaging of brain tumors.

Astrocytoma↗
PubMed2006

Increasing benefit of magnetic resonance imaging in multiple sclerosis.

Magnetic resonance imaging (MRI) has emerged as an essential tool of multiple sclerosis (MS) diagnosis and has opened up completely new prospects in MS research and treatment trials. It is a sensitive method that gives direct evidence of tissue pathology and has greatly increased our knowledge of MS. In clinical work, MRI is used to confirm and exclude the diagnosis of MS. The international recommendation is that every suspected MS patient should undergo at least one brain MRI. T2-weighted images are the standard tool in clinical work, and functional imaging methods are mainly used in MS research. The subtypes and the course of the disease cause variation in MRI findings. Here, we present a general overview of MR findings in MS.

Humans↗
PubMed2004

Cardiovascular autonomic dysfunction correlates with brain MRI lesion load in MS.

OBJECTIVE: The aim of the present study was to investigate the cardiovascular autonomic control in clinically definite multiple sclerosis (MS) patients with a standardised battery of cardiovascular tests and to correlate these findings with the brain magnetic resonance imaging (MRI) lesion load. METHODS: Fifty-one patients with MS and 50 healthy controls were studied. Brain MRI was performed in all patients showing typical MS lesions. The cardiovascular tests were carried out using a standardised battery. RESULTS: Heart rate (HR) responses to deep breathing (P < 0.05) and tilt table testing (P < 0.001) were significantly decreased in MS patients when compared to those of the controls. Blood pressure (BP) responses in the tilt table test were also impaired in MS patients (diastolic P < 0.001, systolic P < 0.05). Of the different brain areas investigated the total volume of the midbrain MRI lesions (P < 0.05) was the one most clearly associated with the impaired BP responses. CONCLUSIONS: MS results in both reduced HR variation and decreased BP reactions indicating disturbed cardiovascular regulation. In particular, the midbrain lesions found in MS are associated with cardiovascular dysfunction.

Adult↗
PubMed2004

Cerebral CT and MRI findings in cervicocephalic artery dissection.

PURPOSE: To explore the frequency and patterns of brain infarction and other brain manifestations in cervicocephalic artery dissection (CCAD) and to evaluate the correlation between vessel wall findings and infarctions. MATERIAL AND METHODS: The medical records and films of 136 consecutive CCAD patients diagnosed in Oulu University Hospital during the 20-year period since 1982 were reviewed. Five patients with no brain imaging were excluded. RESULTS: One-hundred-and-twenty-seven patients underwent cerebral CT and four patients MRI. Brain infarction was detected in 73 patients (56%), 43 of whom had cerebral infarction associated with anterior circulation dissection and 30 cerebellar infarction associated with posterior circulation dissection. Occlusion of the dissected vessel was accompanied by infarction in 76%, irregular stenosis in 40%, and other findings in 12%. Of the anterior circulation infarctions, territorial and subcortical infarctions and territorial infarctions with fragmentation, which are considered embolic, accounted for 95%, while only 5% were in the watershed area and considered hemodynamic. Intracranial posterior circulation dissection rarely caused infarction (in 1/11 of the dissected vessels), whereas intracranial anterior circulation dissection resulted in infarction more commonly (9/12). Altogether 23% of patients with intracranial CCAD had subarachnoid hemorrhage. Hemorrhagic transformation was present in five patients. CONCLUSIONS: More than half of CCAD patients have cerebral or cerebellar infarction at CT or conventional MR imaging. Occlusion of the dissected vessel is accompanied by infarction more often than other vessel wall abnormalities. Most cerebral infarctions caused by arterial dissections are of embolic origin. Intracranial dissections cause subarachnoid hemorrhage in more than 20% of patients.

Adolescent↗
PubMed2004

Factors related to acute hydrocephalus after subarachnoid hemorrhage.

PURPOSE: To evaluate the influence of the amount and distribution of blood on acute ventricular enlargement in subarachnoid hemorrhage (SAH). MATERIAL AND METHODS: In a retrospective study, non-contrast computed tomography (CT) images of 180 patients with aneurysmal SAH were analysed by two neuroradiologists. The amount and distribution of the hemorrhage were scored, and prospective hydrocephalus was identified on the basis of acute CT images by calculating the cella media index, by measuring the width of the third ventricle, and by visual impression. Statistical analysis was done using the logistic regression model, analysis of variance, and chi-square test. RESULTS: The incidence of acute hydrocephalus was higher among the patients with blood distributed in the anterior, lateral, and basal regions (70.8%) than among the patients who did not have blood distributed in all three areas (P=0.010). The proportion of acute hydrocephalus differed depending on the type of hemorrhage (P<0.001). Intraventricular hemorrhage was the most consistent predictive factor in the logistic regression model, while the other predictive factors included the total blood amount score and the volume of intracerebral hemorrhage. CONCLUSIONS: A positive correlation was found between acute hydrocephalus and the amount of subarachnoid and, more importantly, intraventricular blood. This is consistent with the literature and confirms the current pathophysiologic concepts that the acute hydrocephalus following SAH is an obstructive form of hydrocephalus.

Acute Disease↗
PubMed2003

Febrile seizures and mesial temporal sclerosis: No association in a long-term follow-up study.

OBJECTIVE: To determine whether febrile seizures cause mesial temporal sclerosis (MTS), the occurrence of MTS was evaluated in an unselected series of patients with febrile seizures. METHODS: Twenty-four patients with a prolonged first febrile seizure, 8 with an unprovoked seizure after the first febrile seizure, and 32 age-, sex-, and handedness-matched control subjects with a single simple febrile seizure without later unprovoked seizures were selected from 329 febrile seizure patients followed up prospectively. The occurrence of MTS was evaluated after a mean follow-up time of 12.3 years by MR volumetry of amygdala and hippocampal formation and qualitative analysis of mesial temporal structures. RESULTS: None of the patients had MTS. The mean total volumes of the right and left hippocampal formations and amygdala did not differ significantly between any of the three groups. The qualitative analysis revealed no sclerotic changes in the mesial temporal area. The patients with a prolonged initial febrile seizure had a lower mean right-left volume difference in hippocampal formations than the control subjects, but this had no effect on the outcome. CONCLUSION: The occurrence of MTS following even prolonged febrile seizures is an uncommon event, confirming the good clinical outcome of febrile seizures.

Adolescent↗
PubMed2003

Extracranial internal carotid and vertebral artery dissections: angiographic spectrum, course and prognosis.

We reviewed the clinical and radiological findings of 93 consecutive patients with 111 extracranial internal carotid (ICAD) and vertebral artery (VAD) dissections and one concomitant intracranial VAD; 83% of the patients had unilateral and 17% multiple vessel dissections. The diagnosis was made by intra-arterial digital subtraction angiography in 92 patients and MR angiography in one. Follow-up angiography was performed in 77 cases (83%): of 49 initially stenotic arteries, 40 became completely or almost completely normal, while three showed slight improvement. Of 30 initially occluded arteries, nine had completely or partly recanalised. Of 12 pseudoaneurysms eight were unchanged at follow-up. The proximal vertebral artery was involved as often as the C1-C2 level. Recurrences were rare: a new dissection in another vessel was found in three patients. Kinking or coiling was found in 23% of the dissected internal carotid arteries.

Adolescent↗
PubMed2002

MR imaging of pituitary adenomas treated with the prolactin inhibitor quinagolide.

PURPOSE: To evaluate the volume of micro- and macroadenomas in quinagolide-treated patients with resistance to or intolerance of bromocriptine. MATERIAL AND METHODS: The effect of the prolactin inhibitor quinagolide on the volume of pituitary adenoma was evaluated retrospectively in 11 female patients. Prolactin levels before and after the treatment were also recorded. The indications for quinagolide therapy were side-effects of bromocriptine in 5 cases, a poor response to bromocriptine in 5 cases and both in 1 case. MR imaging with a 1.0-T magnet was performed to determine the volume reduction of the adenomas. RESULTS: The average volume reduction of macroadenomas was 324 mm3 (46%) and that of microadenomas 73 mm3 (57%). The level of prolactin secreted by macroadenomas was reduced by an average of 163 microg/l (65%) and that by microadenomas of 113 microg (73%). In 2 microadenomas and in 1 macroadenoma, signal intensity changed during the treatment in T1-weighted images. In follow-up no changes in signal intensity were seen in 8 adenomas in non-contrast T1-weighted images. A haemorrhagic lesion was seen in 1 macroadenoma before treatment, but it disappeared during treatment. CONCLUSION: Quinagolide was found to be an effective alternative to bromocriptine in cases with drug intolerance or resistance, and MR imaging a suitable method for the follow-up of macro- and microadenomas.

Adenoma↗
PubMed2001

MRI findings concerning the lateral pterygoid muscle in patients with symptomatic TMJ hypermobility.

Clinical studies have shown a close association between temporomandibular joint hypermobility (TMJH) and temporomandibular disorders (TMD). While pathological change of the lateral pterygoid muscle (LPM) is one of the most emphasized in studies of TMD, there have been no detailed clinical reports of the LPM studies using magnetic resonance imaging (MRI) in TMJH. This study investigates structural and pathological alterations involving the LPM in patients with TMJH using MRI. A retrospective analysis was made of high-field MRI images from 98 patients with TMJH. LPMs of 143 joints were analyzed. In 110 joints (77%), hypertrophy, atrophy, and contracture were found in the superior belly and/or the inferior belly of the LPM. Pathological changes were more frequently found in the superior rather than the inferior belly of the LPM. In the cases with abnormalities in both bellies of the LPM, hypertrophy of the inferior belly was usually found combined with other changes of the SBLPM. The results of this study indicated that the pathological changes of the LPM or MRI are not infrequent in patients with symptomatic TMJH.

Adolescent↗
PubMed2000

White matter changes on MRI during treatment in children with acute lymphoblastic leukemia: correlation with neuropsychological findings.

BACKGROUND: Treatment of childhood acute lymphoblastic leukemia (ALL) may cause structural and functional brain damage. To find out the incidence of white matter changes during therapy, a prospective MRI study was designed, and the findings were correlated with neuropsychological evaluation. PROCEDURE: Thirty-three children with ALL underwent serial cranial MRI before, during, and after therapy. Twenty-eight of these children underwent also neuropsychological assessment at the end of treatment. They all received intravenous and intrathecal methotrexate for central nervous system (CNS) therapy, 15 patients received cranial irradiation in addition. RESULTS: Transient high-intensity white matter changes were observed by MRI in three children 9% (95% CI, 2-24%) who received chemotherapy only. The high-intensity changes were most prominent in the frontal lobes in two of these children. The children with white matter changes were significantly younger than those with normal MRI (2.8 vs. 7.4 years; mean). There was no correlation between neuropsychological tests and white matter changes, except in attention and in tests referring to the frontal areas in general. CONCLUSIONS: White matter changes are occasionally observed during therapy with the current Nordic protocols. Young children may be more susceptible to developing white matter changes after repeated intravenous methotrexate injections. There is no systematic correlation between neuropsychological deficits and MRI findings.

Adolescent↗
PubMed2000

Radiation therapy approach in gliomatosis cerebri--case reports and literature review.

Gliomatosis cerebri is defined as a remarkably diffuse glioma, characterized by widespread infiltration of the central nervous system. Clinicopathologic characteristics and imaging findings have been published but valid classification remains controversial. Few reports exist regarding therapeutic options in gliomatosis cerebri. Here we review data on 17 patients treated with radiation therapy extracted from the literature, in which we focus our attention on available details of irradiation and clinical outcome and present the results of three additional patients treated at our two institutions. Radiologic-pathologic correlation in gliomatosis cerebri indicates that tumor delineation should be based on T2-weighted MRI. Radiation therapy in gliomatosis cerebri is associated with a temporary improvement in or stabilization of clinical symptoms in the majority of cases. Duration of improvement was > or = 6 months in 50% of treated patients. Survival from onset of symptoms was 23.8 months (range 8-42). Considerable variation in the natural course of the disease precludes conclusions regarding the impact of radiation therapy on survival.

Adolescent↗
PubMed2000

[Imaging the ear].

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Diagnostic Imaging↗
PubMed1999

Dopamine transporters increase in human brain after alcohol withdrawal.

Dopaminergic transmission has been suggested to be a main mechanism mediating reinforcement, withdrawal and craving associated with alcohol addiction. We measured here striatal dopamine (DA) transporter binding from 27 alcoholics within 4 days after cessation of prolonged heavy drinking and after a 4-week period of abstinence with single photon emission computed tomography (SPECT) using a cocaine analogue, iodine-123-beta-CIT. Controls were 29 healthy volunteers. Blind quantitative analyses of the SPECT data revealed markedly lower DA transporter binding in alcoholics on admission for detoxification than in the non-alcoholic controls. After a 4-week period of abstinence DA transporter binding increased significantly in the alcoholics (P<0.0001) reaching the levels of the healthy controls. The most substantial recovery in DA transporter binding occurred during the first 4 days of abstinence. The data indicate that prolonged heavy drinking decreases DA transporter binding and disturbs synaptic dopamine transport. This may sensitize alcoholics to dopaminergic transmission, which may lead to early relapse after ethanol withdrawal.

Adult↗