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Biomedical subjects

J J Mooij

Publications and source records attributed to J J Mooij.

At least 19 recordsLinked to original sources
PubMed1995

Design and application of sensor for recording sounds over human eye and nose.

The recording of sounds over the orbit of the eye has been found to be useful in the detection of intracranial aneurysms. A hydrophone for auscultation over the eye has been developed and is tested under controlled conditions. The tests consist of measurement over the eyes in three healthy volunteers at rest, during voluntary breathing, during eyeball movements and during sustained orbicular muscular contractions. Furthermore, measurements are performed at the side of the nose. Major features of the hydrophonic transducer are high sensitivity to physiological sounds and a high degree of insensitivity to environmental sounds propagated through the air. It can be concluded that the hydrophone may be useful for the early detection of intracranial aneurysms and also for apnoea detection.

Auscultation↗
PubMed1994

Transient mutism and speech disorders after posterior fossa surgery in children with brain tumours.

Four patients aged 5 to 9 years with large tumours located in the posterior fossa (PNET, ependymoma or astrocytoma) are presented. Patients received standard neuropsychological assessments, including speech evaluation, prior to surgery. Following tumour resection, these 4 children developed transient mutism or different types of speech and cognitive disorders, associated with behavioural disturbances. We describe course and results of repeated postoperative neurological and neuropsychological evaluations. Full recovery of speech was seen in 3 out of 4 patients; the only child with persistent symptoms was the one who already had neuropsychological deficits before surgery. However, despite fast recovery of the speech disorders more persistent behavioural problems were found in 3 out of 4 patients. Possible pathogenesis anatomical location of this "cerebellar speech syndrome" are discussed, as well as the relevance of repeated neuropsychological assessments.

Astrocytoma↗
PubMed1994

Noisy intracranial tumours.

Transorbital sound recordings were obtained from 21 patients with intracranial tumours, 28 patients with intracranial aneurysms and 20 control patients. The group of patients with tumours consisted of 12 patients with gliomas, of whom 6 had low-grade gliomas and 6 had high-grade gliomas, and 9 patients with meningiomas. All patients with gliomas, including the subgroup of patients with low-grade gliomas, as well as patients with aneurysms, had significantly different sound recordings in comparison to control patients. Recordings from glioma patients did not differ significantly from recordings of aneurysm patients. Radiological evaluation of the tumours was performed in order to establish which tumour characteristics were associated with abnormal sound recordings. It was found that the type of tumour, i.e., histology or malignancy grade, was a significant associated factor, whereas other tumour characteristics such as size, mass effect and amount of oedema were not. In conclusion, patients with specific types of intracranial tumours produced abnormal sounds which could not be distinguished from abnormal sounds recorded in patients with aneurysms. These results may be important for the interpretation of sounds recorded for the detection of intracranial pathology, especially for aneurysm screening.

Adult↗
PubMed1991

The acoustic detection of intracranial aneurysms: a clinical study.

A new recording method for the acoustical detection of intracranial aneurysms is presented. A study examining the capability of the method to discriminate between patients with an aneurysm and control patients by a simple, objective parameter is reported. Sound signals were recorded over the eyes, and a real-time spectral analysis was performed on these signals. For this study, recordings performed on 26 patients with an aneurysm were compared with recordings on 26 age- and sex-matched control patients without intracerebral abnormalities. As a result of measures taken to reduce artifacts and to improve the signal-to-noise ratio, the measurements were performed reliably, with little inconvenience for the patients; all measurements could be used for analysis. The power spectra measured in the control patients showed a typical, smoothly descending pattern; those measured in the aneurysm patients clearly differed from this pattern, showing peaks of varying width, height, and dominant frequency. For the objective judgment of the power spectra, the power median is introduced. The sensitivity and specificity of this parameter were determined. Possible methods to improve the results will be discussed.

Adult↗
PubMed1988

Evoked potential monitoring and temporary clipping in cerebral aneurysm surgery.

Temporary occlusion of the parent artery greatly facilitates the dissection of large cerebral aneurysms, while much reducing the risk of intraoperative rupture and avoiding the use of profound arterial hypotension. Intraoperative somatosensory evoked potential (SEP) monitoring was carried out in 25 aneurysm cases where temporary clipping was employed electively under moderate hypothermia. Occlusion times ranged from 6.3 to 52 minutes at 28.7 degrees C to 32.5 degrees C. Among 15 middle cerebral artery (MCA) occlusion cases the SEP was lost within 5 or 6 minutes in two cases undergoing early surgery and in one case with marked vasospasm and was lost within 9 minutes in one case with pre-existing infarction in the territory of the MCA. The SEP persisted throughout MCA occlusion periods of 6.3 to 52 minutes in 8 cases. Occlusion of parent arteries of unruptured aneurysms was well tolerated. At least 2 minutes of MCA occlusion after loss of the SEP were tolerated without neurological sequelae, while transient new deficits were seen when MCA occlusion was continued for 4 and for 4 + 11 minutes and an increased deficit was seen when occlusion was continued for 7 minutes after loss of the SEP. In each of the internal carotid artery (ICA) occlusion and bilateral anterior cerebral artery occlusion groups the SEP was lost in one case and was absent for about one minute before reperfusion was instituted. The ICA case had a transient deficit lasting about 4 hours; no other complications were seen in these two groups. Complications were not seen in any case where the SEP was not lost during the occlusion period. Factors affecting collateral perfusion and possible means of increasing tolerance to ischaemia in this situation are discussed.(ABSTRACT TRUNCATED AT 250 WORDS)

Brain↗
PubMed1987

Somatosensory evoked potential monitoring of temporary middle cerebral artery occlusion during aneurysm operation.

Somatosensory evoked potentials (SEPs) in response to median nerve stimulation were used as a guide to cortical function during temporary occlusion of the distal M1 segment of the middle cerebral artery (MCA) in the surgical treatment of five large aneurysms of the MCA bifurcation. MCA occlusion times ranged from 8 to 19 minutes under moderate hypothermia at 28.8 degrees to 30.3 degrees C. SEPs were preserved for variable times during MCA occlusion, ranging from no increase in latency after 13 minutes of occlusion to severe deterioration after 6 minutes. In no case was MCA occlusion maintained for longer than 3 minutes in the presence of a severely disturbed SEP. Recovery of the SEP to its preoperative relationship with that of the nonoperated hemisphere was seen in all cases before the end of operation. All patients were awake after rewarming at the end of operation without any neurological deficit. Monitoring the SEP pertaining to the territory of a cerebral artery during its temporary occlusion can help avoid ischemic damage and will allow the surgeon to take advantage of the several benefits of this technique in aneurysm surgery.

Adult↗
PubMed1986

Progressive neurological deficit in children with spina bifida aperta.

The results of re-operation of 15 patients with spina bifida aperta are reported. The operation was necessary because of neurological deterioration with increasing motor and bladder dysfunction. In all patients a tethered cord syndrome was present (CT-myelography). The myelum was adherent to the scar of the myelomeningocele repair. At operation the myelum is released from the adherent scar and in this way untethered. The early complications were mild except for one patient with decompensation of hydrocephalus. The aim of the operation was to stop further progression. The results of the operation were satisfactory with stabilisation of motor function in four patients and improvement of motor dysfunction in ten patients. Backache or fixation, bladder dysfunction and abnormal foot shape improved in some of the patients. In our experience the operative untethering procedure was useful. Intensive neurological control of operated spina bifida aperta patients is mandatory especially in those patients who can walk.

Adolescent↗
PubMed1984

The cause of failure in high cervical percutaneous cordotomy: an analysis.

Factors that might have contributed to failure of high cervical percutaneous cordotomy in 23 patients with intractable pain were investigated. Cordotomy failed in 3 patients, 20 had initially good pain relief (87%). True recurrence occurred in 5 patients, 3 of them developed pain elsewhere. Analysis of these three types of failure showed a purely technical cause in 2 cases; other failures or recurrences were due to the underlying disease being not strictly unilateral, or possibly to the existence of other ascending pathways carrying nociceptive impulses apart from the spinothalamic tract. There was no influence of age, sex, type of cancer or previous medication on the result of percutaneous cordotomy. Patients with plexus involvement did better than those with bone metastasis.

Aged↗
PubMed1982

Ulnar nerve pathology at the elbow: the place of anterior transposition today.

A retrospective study is presented of 39 patients with ulnar nerve pathology at the elbow. All patients were treated by anterior transposition. Improvement to at least good functional recovery occurred in 46% of the patients. In the other 54% there was only slight or no improvement, or even deterioration. A further analysis of the results showed that in patients with objective signs of ulnar pathology, but without muscular atrophy, the results were good: 64% of these patients showed a good operative result. The most important factors in postoperative prognosis in the patients studied are the existence of muscular atrophy, age, and, in the moderately severe group, the length of history before operation. The aetiology was not important with respect to the outcome. On the basis of the recent literature and the results of this study suggestions are presented for a rational choice between the different possibilities of treatment for ulnar nerve pathology at the elbow.

Adult↗
PubMed1980

[Arachnoiditis].

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Arachnoiditis↗
PubMed1980

Spinal arachnoiditis: disease or coincidence?

In 86% of 63 patients with spinal arachnoiditis the localization was lumbosacral, and in 14% it was cervical or thoracic. The most important aetiological factor was the combination of one or more myelographies with one or more operations. It is remarkable that in most patients with lumbosacral arachnoiditis the clinical picture did not show new or typical signs of arachnoiditis, but was the same as before the arachnoiditis had developed. In only 20% of patients with lumbosacral arachnoiditis, and in all patients with cervical or thoracic arachnoiditis, did new signs and symptoms occur concomitantly with and due to the development of the arachnoiditis. The results of this retrospective study suggest that lumbosacral arachnoiditis is a coincidental finding in the majority of cases, without clinical consequences.

Adolescent↗
PubMed1976

Potassium induced potential changes in rat diaphragm muscle.

The effect of different potassium concentrations on the membrane potential and membrane resistance of rat diaphragm muscle fibres was measured by means of a double sucrose gap method and a microelectrode technique. Concentration measurements showed that the muscle fibres gained sodium and lost potassium in the equilibration period. In the absence of external chloride changing the external potassium concentration from 2.8 mM to potassium-free caused a depolarization of the membrane of about 30 mV and a small increase in membrane resistance. This K-dependent potential change (K-response) was induced by ouabain, K-strophanthin, 2,4-dinitrophenol and cyanide, indicating that an energy requiring process is involved. The temperature dependence of the K-response found is consistent with this assumption. Variation in potassium permeability in the absence and presence of external potassium could account for only 13% of the K-response. The K-response amplitude appeared to depend on the external potassium and the internal sodium concentration. Hyperpolarization of the membrane could not only be produced after readmission of potassium but also after addition of thallium, the latter being more potent. Raising the external chloride concentration resulted in a decrease of the K-response and membrane resistance. The current, generating the K-response was shown to be hardly influenced by conditional polarization of the membrane. It is concluded from these results that the K-response is mainly due to the operation of an electrogenic sodium pump.

Animals↗