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Biomedical subjects

J Pyhtinen

Publications and source records attributed to J Pyhtinen.

At least 55 records · Page 3Linked to original sources
PubMed1993

Parotid gland carcinoma simulating signs and symptoms of craniomandibular disorders--a case report.

The following case involves a 33-year-old woman who received two accidental blows to her left temporomandibular joint (TMJ) region six months before her first visit to the Institute of Dentistry, University of Oulu. Both clinical and computed tomography (CT) examinations of this left TMJ strongly favored a diagnosis of craniomandibular disorders (CMD). However, a fine needle biopsy and an histopathological examination of the parotid gland established the final diagnosis as poorly differentiated adenocarcinoma of the parotid gland. The course of the disease was very aggressive developing several metastases, and the patient died 24 months after the diagnosis. The presence of facial nerve paralysis, especially in combination with cheek numbness in the parotid region, should have strongly suggested the possibility of such a malignancy.

Adenocarcinoma↗
PubMed1993

A prospective one-year follow-up study with somatosensory potentials evoked by stimulation of the median nerve in patients with cerebral infarct.

Somatosensory potentials evoked by stimulation of the median nerve (median nerve SEPs) were studied in a prospective and sequential series of 40 patients with first supratentorial and nonhaemorrhagic cerebral infarct. In 35 patients the SEPs were recorded three times during the first year after the stroke. The location of the infarcted zone was reflected in the number of detected abnormalities: most patients with infarct changes extending to the gray matter of the Rolandic cortex showed abnormalities in the median nerve SEPs, and all patients with involvement of both precentral and postcentral cortical gray matter had abnormal median nerve SEPs. In the entire patient group when both latency and amplitude abnormalities were included about half (48%) of the patients had abnormal median nerve SEPs a week after the stroke, 39% 2-3 months after the stroke and 29% about one year after the stroke. These changes were not significant. When separately surveying the changes in the numbers of latency and amplitude abnormalities the difference between the first and the third examinations was nearly significant only in the number of latency abnormalities. Furthermore, in the absolute latency and amplitude values, no significant changes could be seen within the first two-three months after the infarct; within the whole one-year follow-up period a nearly significant change was noted between the second and the third examination in only one parameter (P22 peak latency). Thus, the abnormalities in the median nerve SEPs, especially the amplitude abnormalities, were relatively permanent during the one-year period after cerebral infarct.

Adult↗
PubMed1992

White matter changes in children treated for acute lymphoblastic leukemia.

BACKGROUND AND METHODS: Twenty-seven children with acute lymphoblastic leukemia (ALL) were studied by magnetic resonance (MR) imaging after central nervous system (CNS) treatment. The children were followed by clinical evaluations and computed tomographic (CT) brain scans. Two CNS treatment techniques were used. Eleven patients received intravenous and intrathecal methotrexate; 16 patients received 18-30 Gy of cranial radiation therapy in addition to systemic chemotherapy. The time interval between the CNS treatment and MR scans varied from 9 months to 4 years 8 months. RESULTS: Four of the 27 children (15%) showed white matter changes on the MR scans attributable to therapy, but only one had hypodensity on CT. Three of the 16 children (19%) receiving radiation therapy in addition to chemotherapy had white matter changes. One of the 11 patients (9%) from the group receiving only chemotherapy did so. The difference between the two treatment groups was not significant. CONCLUSIONS: Radiation therapy or chemotherapy (alone or in combination) may have been responsible for the white matter changes. MR imaging is a sensitive detector of white matter changes in children with ALL, but its value and significance during follow-up should be assessed in well-designed longitudinal research studies.

Adolescent↗
PubMed1991

Relationships of bicondylar position to occlusal asymmetry.

Mandibular asymmetry in the frontal plane is a common finding, the left side of the mandible being more often the longer one, and a progressive trend for a more post-normal occlusion on the right side as compared to the left has been reported recently. The aim of the present work was to measure bicondylar asymmetry using computed tomography (CT) and to determine whether this is correlated with certain occlusal characteristics in young adults with no gross malformations. The subjects were 49 adults aged from 15 to 33 years, mean 24.2 years (SD 3.79 years). All of them had a complete or nearly complete dentition. The left condyle was found to be more anteriorly located on average and to be positioned closer to the skull base midline than the right condyle. The joint space between the condyle and the posterior wall of the glenoid fossa was larger on the left side. The asymmetry in bicondylar position correlated with the occlusal asymmetry. Subjects with lateral malocclusions showed a more asymmetric position of the condyles with respect to the posterior wall of the glenoid fossa. This may be of clinical importance and stresses the necessity for early correction of such malocclusions, as complete adaptation does not seem to occur in these cases.

Adolescent↗
PubMed1991

Clinical and CT correlates in the diagnosis of intracranial tumours.

The correlation between clinical and CT findings in cerebral tumours was prospectively studied in 1191 consecutive referrals for cerebral CT. CT revealed a mass lesion in 51 cases (4.3%): 32 neoplasms, five haematomas and one abscess. The diagnostic specificity of CT for neoplasmic tumours was 86% (32 of 37). The clinical suspicion of a cerebral neoplasm was correct in 25 cases (78%) and the clinical localisatory hypothesis was correct in 20 cases (63%) of the neoplasms. A cerebral tumour was found in 5% (11 out of 226) of patients investigated for their first seizure and in 1% (two of 207) investigated for headache without clinical signs.

Adolescent↗
PubMed1991

Computed tomography of the masticatory system in rheumatoid arthritis.

The resolution of computed tomography (CT) allows evaluation of hard and soft tissues of the masticatory system. Eleven patients with RA were scanned by CT in direct sagittal and coronal projection because of temporomandibular joint problems. Our results indicate that in addition to bony changes there are changes in the masticatory muscles. These are detectable by CT and may be caused by the RA itself or related to impaired function.

Adult↗
PubMed1991

Median nerve and posterior tibial nerve somatosensory evoked potentials in the non-affected hemisphere: a prospective one-year follow-up study in patients with supratentorial cerebral infarction.

Somatosensory potentials in the non-affected hemisphere evoked by simulation of both the median nerve (median nerve SEPs) and the posterior tibial nerve (tibial nerve SEPs) were studied in 40 patients with supratentorial nonhaemorrhagic cerebral infarction three times during a one-year follow-up period. The EP-N20 interpeak latencies (IPLs) of the median nerve SEPs were on average longer in the patient group than in the control group (especially in patients with evidence of mass displacements in the cerebral computed tomography), whereas no significant differences were observed in the amplitudes of the median nerve SEPs. The P57-N75 amplitudes of the tibial nerve SEPs were on average lower in the patient group than in the control group. During the follow-up period the peak latencies and the P40-N75 IPLs of the tibial nerve SEPs increased and the amplitudes of the tibial nerve SEPs diminished.

Cerebral Infarction↗
PubMed1990

Morphology of the condyles and mandibular fossa as seen by computed tomography.

Computed tomography allows detailed three-dimensional examination of the hard and soft tissue of the temporomandibular joint. The morphology of the mandibular fossa and the condyles together with the horizontal and vertical condylar inclinations was determined in 25 patients with temporomandibular joint dysfunction and 29 controls by use of axial and coronal computed tomography projections. The shape of the condyle was evaluated according to its general appearance. The temporomandibular joint measurements obtained by computed tomography were in good agreement with morphologic studies performed on dry skulls and autopsy material.

Adolescent↗
PubMed1990

Conventional radiographic and computed tomographic findings in cases of fracture of the mandibular condylar process.

A total of 40 patients with 46 fractures of the mandibular condylar process were examined an average of 47 months after the injury. The conventional radiologic examination consisted of panoramic radiography and lateral transcranial view of the fracture in the mouth-open and mouth-closed positions. Sixteen patients with 21 fractures of the condylar process were examined additionally by computed tomography (CT) because of temporomandibular joint problems in the sagittal and coronal projection. Computed tomography revealed bony changes in the fractured mandibular condyle and its position in the mandibular fossa more exactly than conventional radiographic examinations. Furthermore, the results showed that disturbances in the position and function of the articular disc may be more common than was earlier anticipated, suggesting the more frequent use of CT examinations to evaluate temporomandibular joint changes after condylar process fractures.

Adolescent↗
PubMed1990

Changes in the main masticatory muscles in CT after mandibular condyle fracture.

The aim was to study changes in the main masticatory muscles after mandibular condyle fracture as seen by CT, comparing the densities and sizes of the masseter, medial pterygoid and lateral pterygoid muscles on the fractured side with those on the non-fractured side. More or less permanent muscular changes are detectable several years after the accident, especially in the lateral pterygoid muscle, which is attached to the condylar head. This muscle was statistically significantly smaller (p less than 0.001) on the fractured side. Examination of the masticatory muscles immediately after the fracture and at intervals afterwards could reveal more about the pathogenesis of the changes in these muscles.

Adolescent↗
PubMed1990

Development of posttraumatic epilepsy.

Ten out of 55 patients with closed cerebral injury were documented to develop posttraumatic epilepsy in a prospective follow-up study comprised of repeated clinical, CT, CBF, and neuropsychological examinations. Primary convulsions, focal intracerebral hemorrhagic lesions at the acute stage, and pronounced, mainly subcortical atrophy, as well as impaired local CBF 3-12 months after the injury were the factors which were associated significantly often with posttraumatic epilepsy. Antiepileptic prophylaxis should be focused in cases presenting these risk factors, and might be wise to be continued for several years, at least in patients with chronic alcoholism.

Adolescent↗
PubMed1990

Correlation of clinical and computed tomographic findings in stroke patients.

We evaluated the correlation between clinical features and computed tomographic findings in a prospective study of 1,191 consecutive patients with acute cerebrovascular disease seen during 1 year. In the 386 patients in whom symptoms and signs initially suggested a cerebrovascular disorder, computed tomography revealed a relevant lesion in 154 (hemorrhagic in 52 [33.8%], ischemic in 102 [66.2%]) and a significant nonstroke abnormality in 14 (3.1%). Among the remaining 805 patients with symptoms and signs suggesting some central nervous system disorder other than stroke, computed tomography revealed a cerebrovascular lesion in 38 (4.7%); 35 of these lesions were ischemic. The computed tomographic findings was compatible with the final clinical diagnosis in 192 (84.2%) of the 228 patients with lesions. In the entire sample of 1,191 patients, a cerebrovascular disorder would have been missed in 38 (3.2%) without computed tomography. On the other hand, computed tomography failed to visualize a cerebrovascular lesion in 40 patients in whom such a lesion was clinically obvious. Our results emphasize that both careful neurologic assessment and a policy of early computed tomography are of crucial importance in the diagnosis of stroke and for therapeutic considerations.

Adolescent↗
PubMed1990

Effective clinical response to long term octreotide treatment, with reduced serum concentrations of growth hormone, insulin-like growth factor-I, and the amino-terminal propeptide of type III procollagen in acromegaly.

Ten patients with active acromegaly, six with a poor response to previous therapies and four newly diagnosed, were treated with the long-acting somatostatin analog octreotide (Sandostatin; 200-500 micrograms/day, sc, twice or three times daily) for 6-15 months. There was rapid clinical improvement in all patients. The mean daily serum GH concentration was reduced by 64% and was normalized (all GH values less than 2 micrograms/L) in three patients. Serum insulin-like growth factor-I (IGF-I) concentrations were lowered by 40% and were normalized in eight patients. Serum concentrations of the amino-terminal propeptide of type III procollagen (PIIINP), an index of tissue collagen metabolism, were reduced by 40% and were normalized in all patients with initially elevated values. There was a statistically significant positive correlation between the mean serum GH and IGF-I levels (r = 0.47; P less than 0.001) as well as between serum GH and PIIINP levels (r = 0.34; P less than 0.05) and between serum IGF-I and PIIINP (r = 0.50; P less than 0.001). The effects of octreotide on pituitary tumor size and pathology were evaluated in one patient. The therapy did not seem to be associated with significant changes in sellar computed tomographic scans or light microscopic findings. The drug was generally well tolerated. However, indications of significant hepato-biliary dysfunction were noted in one patient after 5 months of therapy. This was reversible upon discontinuation of therapy and did not occur later during the rechallenge with a lower dose of the drug. However, there was probably newly formed cholelithiasis in four patients during the therapy. Our study suggests that octreotide is an effective and relatively safe new approach for treating active acromegaly. Further studies are needed to investigate long term effects on the hepatobiliary system.

Acromegaly↗
PubMed1989

Plain radiography and tomography of the internal auditory canal for the diagnosis of acoustic neuroma.

In the series of 50 acoustic neurinomas (AN) the internal auditory canal (IAC) diameter and the diameter difference between the tumor and non-tumor side are compared with the sizes of the AN. No correlation is found. About 50% of the AN cases had normal ipsilateral IAC in plain and tomographic radiographies. A pathological IAC finding strongly favours AN, but the border between a normal and pathological finding is not an exact one. A normal plain and tomographic radiography does not exclude AN and further investigations cannot be avoided. Our conclusion is that plain radiograms and tomograms have no place in the modern diagnosis of AN.

Ear, Inner↗
PubMed1988

Significance of cerebral CT in neurological practice.

The significance of cerebral CT in neurological diagnostic practice was analysed in this prospective study on 1191 consecutive patients investigated during a one-year period. CT abnormalities were detected in 601 cases (51%), local hemispheral lesions (22%) generalized atrophy (19%) and infratentorial lesions (5%) being the most common findings. In the cases which had presented at referral to CT with clinical indices suggesting cerebral pathology the CT was abnormal in 71% (379 of 537) while the percentage was 34 (222 of 654) in the cases in which CT was performed for exclusion criteria. The clinical diagnostic reviewed by CT accuracy was 88% in cerebral tumours, 69% in cerebral infarction and from 83% to 94% in various intracranial hemorrhages but only 51% in cerebral atrophy which was the most common CT finding without clinical correlates. Apart from atrophy, CT revealed other pathology than clinically suggested in 147 cases (e.g. cerebral infarct in 58, hemorrhage in 16, tumour in 8 and diverse abnormalities in 54 cases). Contrast medium enhancement (used in 45% of the scans) provided more information when compared with the plain scan in 16% (86 of 537), no more than 3 lesions (0.6% of the enhanced scans; 2 meningeomas and one vascular malformation) being visible with enhancement only.

Adolescent↗
PubMed1987

CT detection and location of intraorbital foreign bodies. Experiments with wood and glass.

The series comprises 27 patients examined by CT to detect, locate or exclude a foreign body. 22 of them actually had an orbital foreign body. In three cases CT was the primary method and showed the foreign body correctly, while in 18 it was first detected in plain films and CT was performed to locate it. 20 metallic foreign bodies were hyperdense in appearance. Two cases had wooden foreign bodies, one with a density of +10 HU and the other hypodense with a value of about -434 to -446 HU. The latter piece of wood was first interpreted falsely as a bubble of gas. The results proved that the detection of metal is easy, but differentiation between wood and gas is problematical. Experiments conducted to determine the CT densities of different pieces of wood gave results varying from -618 HU to +23 HU. The highest densities obtained for glass varied from +522 HU to +2000 HU. The density of a plastic lens was -105 HU.

Adolescent↗