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Biomedical subjects

J Siivola

Publications and source records attributed to J Siivola.

16 recordsLinked to original sources
PubMed2002

Piezoelectric film transducer for recording of oculography in electro-encephalogram-polygraphy.

Oculography is important during clinical electroencephalography (EEG). Routinely, silver-silver plate/cup electrodes have been used. However, the electrical activity of the anterior parts of the brain can be mixed with the effect of eye/eyelid movements. This can result in artifacts disturbing or making it impossible to differentiate the frontal activity of the brain from eye movement artifacts. Therefore, crystal piezoelectric materials have been used for oculography, but they are relatively fragile in practice. In this study we present a new type of piezoelectric transducer for the recording of oculography, a piezoelectric polyvinylidenefluoride (PVDF) film transducer. Our preliminary material consists of routine EEG recordings of 15 subjects performed by means of this method. All recordings were of good quality and corresponded well with the routine electro-oculography recordings.

Adolescent↗
PubMed2001

Familial carpal tunnel syndrome: a report of a Finnish family.

The existence of familial carpal tunnel syndrome (FCTS) as a separate autonomic entity has been discussed during the last few years. In order to contribute with more data to the literature, we report here the results of clinical. electrophysiological, pathological and radiological studies performed in 5 patients belonging to the same Finnish pedigree. The disease appeared usually before the second decade with numbness and pain on the I--III digits. In most patients symptoms were unilateral but within 2 years they became bilateral. In all patients typical electrophysiological features of median nerve entrapment have been recorded. X-rays of the wrist showed narrow carpal tunnel in all patients. In all patients the possibility of having HNPP as well as familial amyloidosis has been excluded by molecular genetic and pathological studies. All patients underwent surgery and at postoperative stage symptoms were relieved or completely disappeared. Our study supports the theory that FCTS exists as a separate autonomic entity, therefore it is important in front of a sporadic case to investigate the family occurrence of CTS.

Adolescent↗
PubMed1998

Non-invasive piezoelectric transducer for recording of respiration at the level of diaphragm.

In this study, piezoelectric polyvinylidenefluoride (PVDF) wire was used in construction of a transducer for recording of respiration. The recordings have been performed in 202 subjects, mainly during normal routine electroencephalography (EEG) examinations. Comparison of the PVDF wire transducer with the piezoelectric Siemens Movement Sensor 230 was performed. The recordings of respiration showed highly similar curves with both methods. The PVDF wire transducer seems to record the breathing movements at the level of the diaphragm with great reliability in EEG-polygraphy and it is inexpensive, easy to use and to clean.

Adolescent↗
PubMed1997

Neurophysiological findings in the northern epilepsy syndrome.

We describe the neurophysiological findings in the northern epilepsy syndrome (NES), an autosomal recessively inherited childhood onset epilepsy with associated mental deterioration. Sixty-five EEGs of 18 patients (10 females and 8 males) from the age of 5 years to 52 years were analyzed. EEG showed relatively slight changes at the outbreak of epilepsy at the mean age of 6.6 years (range 5-10 years). Slowing of the background activity to 6-7 Hz theta activity, abundant diffuse or intermittent theta and delta activity and disappearance of sleep-specific activity characterized the EEGs at puberty. The amount of diffuse delta and theta activity diminished in adulthood. Epileptiform findings were scanty. Spikes and sharp waves occurred in 43% of the recordings with varying localization, form and extent. Intermittent 2-4 Hz sharp and slow wave rhythm was seen in 32% of the recordings. Of the three ictal recordings, one showed a primarily generalized discharge pattern, while two were clearly asymmetric. Clonazepam was the most effective antiepileptic drug, and it also normalized the EEG when started in childhood or at the onset of puberty. Visual evoked potentials were abnormal in 44% and brainstem auditory evoked potentials in 35%. The neurophysiological findings suggest an extensive, probably multifocal degenerative brain process, which reaches its peak at puberty. Although the abnormal features of EEG often decreased in adulthood, the clinical course of NES showed slow progression throughout the lifetime.

Adolescent↗
PubMed1986

Somatosensory evoked potentials in evaluation of decompressive surgery of cervical spondylosis and herniated disc.

Somatosensory evoked potentials (SEPs) were studied in patients with cervical radiculopathy and/or myelopathy caused by spondylosis or herniated disc. SEP-recordings were performed before and after operation using an averaging technique by stimulating the median nerve separately at both wrists, with surface electrodes at three different levels: Erb's point, 7th cervical spine and inion. During the follow-up time all patients showed improvement of clinical symptoms. The preoperative SEP recording was abnormal in one or more parameters in all patients. Notable improvement (6-36 months postoperatively) of these abnormalities was observed in 12 out of 14 radiculopathy patients and in 4 out of 9 myelopathy patients. Only in the radiculopathy series could a statistically significant improvement (p less than 0.01) be found in two SEP parameters (amplitude N13 and relative amplitude difference of N13 amplitude). Therefore SEP abnormalities are commonly present in cervical radiculopathy and particularly in cervical myelopathy, and seem to be quite persistent postoperatively, even though clinical improvement especially in the form of pain relief is achieved.

Adult↗
PubMed1983

Somatosensory evoked responses as a diagnostic aid in thoracic outlet syndrome. A postoperative study.

In the present study we have recorded evoked responses in the supraclavicular fossa (Erb's point) following stimulation of the median and ulnar nerves separately on both sides, in patients with thoracic outlet syndrome. Nine out of the 13 patients showed abnormal findings in the preoperative recordings when compared to the recordings of the 20 healthy controls. The first postoperative recordings were performed two months after operation and 3 out of 9 patients with the abnormal preoperative recordings showed normalized results and in addition 2 patients, about one to two years after the operation in the second postoperative recordings. It is suggested that the Erb's point recordings may be of value not only in the diagnosis of thoracic outlet syndrome but also that these recordings are possibly suitable for postoperative follow-up of this disorder.

Adolescent↗
PubMed1982

Spinal evoked potentials evaluated with two relevant electrode types.

The spinal evoked potentials (SEPs) were recorded at the level of the 7th lumbar segment in five cats by stimulating the popliteal nerve separately on both sides. The recordings were performed both with silver-silver chloride cup electrodes and stainless steel needle electrodes. The shapes and latencies of the responses were highly similar, when comparing the responses recorded with the two electrode types as shown by means of transfer function: attenuation and phase curves for both electrode types are highly similar in the bandpass used in the present study. It is concluded that the properties of stainless steel needle electrodes are highly correspondent with the conventional silver-silver chloride electrodes when somatosensory evoked responses are recorded.

Animals↗
PubMed1982

Somatosensory evoked responses as a diagnostic aid in thoracic outlet syndrome. A preoperative study.

Responses evoked in the supraclavicular fossa (Erb's point) were recorded after stimulation of the median and ulnar nerves separately in both arms. The recordings were made in 20 healthy controls and 13 patients with unilateral thoracic outlet syndrome. In 12 of the 13 patients subsequent surgery clearly confirmed the diagnosis. Nine of the 13 patients showed abnormalities in the preoperative recordings at Erb's point. In all of these nine patients the relative amplitude difference on the affected side was outside the normal range. In two patients there was also abnormally low conduction velocity. The differences of amplitudes in the Erb's point responses between patients and controls were statistically significant. The suggestion is made that Erb's point responses evoked by stimulation of the median and ulnar nerves may be of diagnostic value in thoracic outlet syndrome and that the method is suitable as a supplement to conventional electroneurography in routine clinical practice.

Adolescent↗
PubMed1981

Somatosensory evoked potentials in diagnostics of cervical spondylosis and herniated disc.

Somatosensory evoked potentials (SEPs) were recorded in 16 healthy controls and 12 patients suffering symptoms typical of cervical spondylosis and/or herniated disc and showing abnormal findings both in clinical and myelographic examinations. SEP recordings were performed at 3 different levels of the nervous system, at Erb's point, over the 7th cervical spine and at the inion, by stimulating the median nerve separately at both wrists. Nine of the 12 patients were chosen for surgical treatment, while 3 patients received physiotherapy. Six out of the 12 patients showed abnormal findings in SEP recordings, while the 3 patients chosen for the physiotherapy group showed normal SEP recordings. In the present study the amplitudes of the responses may seem to reflect nerve lesions caused by spondylotic deformities more than the latencies of responses. The results suggest that the SEP recordings may have value as a diagnostic aid in cervical spondylosis and spinal stenosis, which finding is in agreement with those of some other authors.

Adult↗
PubMed1980

Estimation of the brain and spinal cord conduction time in man by means of the somatosensory evoked potentials and F and H responses.

Somatosensory evoked potential (SSEP) recordings from the scalp were performed in 17 healthy subjects. In seven of these SSEP was also recorded at the level of the second lumbar spine. In the other ten F and H responses and the corresponding M responses were studied. By means of the SSEP recordings at the level of the second lumbar spine and the F- and H-responses, the conduction time in the brain and spinal cord, that is central latency, was calculated and the following results were obtained: 16.0 ms with standard deviation (SD) +/- 1.1 ms (by means of SSEPs), 9.5 +/- 2.4 ms (by means of F response) and 13.1 +/- 1.5 ms (by means of H response). Of the three methods used the H response method seems to be the best for clinical purposes: it is easy to perform and statistically it is more stable than the F response recording; moreover the recording can be performed reliably even in persons with thick back muscles and subcutaneous fat, unlike the evoked potential procedure which only with difficulty shows detectable responses at the lumbosacral levels in such persons. Three patients are presented to illustrate the technique; in one of these the recording evoked potentials from the epidural space were recorded.

Adolescent↗
PubMed1979

Brachial plexus and radicular neurography in relation to cortical evoked responses.

An application of somatosensory potential recording suitable for clinical neurodiagnostics is described. Evoked responses were recorded with surface electrodes at four levels between wrist and scalp: Erb's point, seventh cervical spine, inion, and the somatosensory area of the scalp. The normal latency and latency difference values based on 16 healthy subjects are presented as well as those of four examples of pathological cases with lesions at various levels in the nervous system. The method presented offers novel possibilities for solving problems of differential diagnosis, especially at the level of the brachial plexus.

Adult↗