Biomedical subjects

L Bognar

Publications and source records attributed to L Bognar.

10 recordsLinked to original sources

PubMed1995

Level of consciousness and age as prognostic factors in aneurysmal SAH.

The prognostic value of the level of consciousness and the patient's age for the outcome of aneurysmal subarachnoid haemorrhage (SAH) is studied in 74 patients admitted on day (D) 0 to D3 after aneurysm rupture. For the level of consciousness three groups of patients are compared: grade I+II (alert patients), grade III+IV (drowsy patients), and grade V (comatose patients). For the age, two groups are compared: patients aged under 50, and patients aged 50 and over. The timing of surgery was: D0-D3 51%, D4-D6 20%, D7 and later 18%, and No surgery 11%. The overall management results were: Good (satisfactory result) 43%, Fair (moderately disabled) 18%, Poor (severely disabled+vegetative survival) 19%, and Death 20%. The outcome was strongly related to the level of consciousness, the rates of Good result decreasing from 71% (grades I-II) to 14% (grades III-IV) and to zero (grade V), and the mortality rates increasing respectively from 5% to 14% and 61%. The relationship between outcome and age was less marked: 54% Good result under 50 and 30% over 50. Out of the Grade V group, 56% could be operated upon and 44% died before surgery. No patient from the other two groups died before surgery. The literature concerning the Grading Systems published so far and the various prognostic factors are discussed.

Aged↗

PubMed1995

Auditory evoked potentials in a patient with a unilateral lesion of the inferior colliculus and medial geniculate body.

Brain-stem, middle latency and late auditory evoked potentials (BAEPs, MLAEPs and LAEPs, respectively) were recorded in a patient 2 months after removal of affecting the quadrigeminal plate. Simultaneously, MRI showed a left unilateral lesion involving the inferior colliculus, brachium colliculi and the medial geniculate body (MGB). On dichotic listening, there was complete extinction of the right ear input, without subjective auditory disturbance. BAEPs were abnormal after stimulation of the right ear alone. Wave V was delayed and reduced in amplitude, and the I-V interval was augmented. Above all, MLAEPs of both ears were very abnormal. The Pa and Na components over the left hemisphere were abolished (Pa) or very reduced in amplitude or abolished (Na) whereas both Pa and Na components over the right hemisphere were normal. LAEPs were asymmetrical, with reduced P1N1P2 complex over the left hemisphere and absence of polarity reversal over the mastoid. It has been demonstrated that a lesion affecting only the inferior colliculus and MGB unilaterally and not extending beyond the MGB can abolish Na and Pa ipsilaterally. Any discussion of Na and Pa sources should take into account the output of the MGB to the auditory radiations, the MGB, the brachium colliculi and the inferior colliculus.

Acoustic Stimulation↗

PubMed1994

Tectal plate gliomas. Part I: Microsurgery of the tectal plate gliomas.

A series of 12 patients with tectal plate gliomas, is presented treated by direct surgery. Mean age was 19 years. All patients presented with signs of raised intracranial pressure and supratentorial hydrocephalus on CT scan. Diplopia was the most common local sign. CT scan and MR imaging showed 4 intrinsic, 6 exophytic, and 2 ventrally infiltrating tectal tumours. The histological diagnosis was low-grade astrocytoma in 7, high-grade astrocytoma in 2, oligodendroglioma in one, oligo-astrocytoma in one, and ependymoma in one case. The suboccipital supra- and transtentorial approach was used in every cases. Tumour resection was generous at the level of the superior colliculi, but on the contrary, resection was limited at the level of inferior colliculi due to the auditory risk. Tumour removal was total (macroscopically) in 9 cases and partial in 3 cases. There were 4 surgical complications and one death related to surgery. Parinaud's syndrome was the most-common postoperative sequelae. Auditory hallucinations and the acoustic neglect syndrome were seen once. In three cases additional radiotherapy and chemotherapy were given once with severe sequelae. The treatment of tectal plate gliomas is controversial. The role of different therapeutic options remains open. We consider the tectal plate as a relatively safer territory for surgery than the ventral part of the midbrain. The brain stem auditory evoked potentials (BAEPs) and middle latency potentials (MLPs) monitoring can help to determine the appropriate limit of surgery.

Adolescent↗

PubMed1994

Tectal plate gliomas. Part II: CT scans and MR imaging of tectal gliomas.

CT scans and MR images were analyzed in 12 patients with histologically proved tectal plate gliomas. In an attempt to identify the nature of these lesions, their radiological characteristics were correlated with the histological results. In four of our patients CT scan failed to show the tumour. MR imaging demonstrated the tectal distortion in all cases. Contrast enhancement, calcification, cystic portions, exophytic nature were observed in both high and low-grade gliomas. We conclude that in the case of intrinsic tectal tumours, the most probable diagnosis is that of low-grade astrocytoma while in the case of exophytic tectal tumours, the differential diagnosis from pineal region tumour is required and a histological verification is necessary.

Adolescent↗

PubMed1994

Tectal plate gliomas. Part III: Apparent lack of auditory consequences of unilateral inferior collicular lesion due to localized glioma surgery.

The authors present one of their cases operated on for intrinsic tectal plate glioma. The complete resection of the right inferior colliculus (I.C.) had no apparent auditory consequences. The pre- and post-operative tonal and vocal auditory tests were normal. The brain-stem auditory evoked potentials (BAEPs) and middle latency potentials (MLPs) were recorded pre-, post- and intraoperatively. At the end of surgery all waves were present with a marked delay of wave V and a slight delay of the Pa component. The dichotic test showed a significant right ear extinction but admittedly much less important than expected. The role of inferior colliculus (I.C.) in hearing is discussed.

Astrocytoma↗

PubMed1994

Auditory early- and middle-latency evoked potentials in patients with quadrigeminal plate tumors.

Both early auditory evoked potentials (BAEPs) and middle-latency auditory evoked potentials (MLAEPs), were recorded in nine patients suffering from a quadrigeminal plate tumor. These recordings were performed before surgery in six cases and after surgery in three cases. The results of these examinations were correlated with impairments of the midbrain auditory pathways as shown by magnetic resonance imaging. BAEPs and MLAEPs were abnormal in five of nine cases and eight of nine cases, respectively. The two examinations yielded normal results in only one case. These data show that the functional evaluation of the midbrain should not be limited to the recording of BAEPs, routinely performed for brain stem functional evaluation, but should also include recording of MLAEPs, although the technique is a little more delicate. In the five patients with abnormal BAEPs, I-V conduction time was increased unilaterally (three patients) and bilaterally (two patients), and the I/V amplitude ratio was abnormal in two patients. In one of these two patients, isolated destruction of the right inferior colliculus was responsible for an abnormality affecting Wave V of the BAEP that was visible only after left ear stimulation. The most frequently observed MLAEP abnormality was a delay in the peaking of the Pa component, assumed to be of cortical origin. Therefore, a limited impairment of the midbrain may delay the peaking latency of Pa. Unilateral hypovoltage of Na-Pa was also observed. In only one case were Na and Pa components unilaterally abolished, in a patient suffering from a postoperative lesion extending from the right inferior colliculus to the right medial geniculate body.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1992

Surgical management of unruptured intracranial aneurysms. Personal experience with 37 cases and discussion of the indications.

The authors report a series of 37 cases of unruptured aneurysms, admitted and operated upon over a 5 year period (1985-1990), which represents an incidence of 18% of the total number of aneurysm patients operated upon during this period. These unruptured aneurysms were discovered in 4 types of circumstances: 1) Associated with a ruptured aneurysm but treated in a second procedure (9 cases); 2) After a transient ischaemic attack (6 cases); 3) After a cerebral haemorrhage of a different origin (3 cases), 4) After the onset of various neurological symptoms other than SAH (19 cases). Giant aneurysms (over 2.5 cm in diameter) are excluded from this series. Overall these 37 patients harboured 52 aneurysms, and 1 patient was operated upon on both sides. 27 aneurysms (52%) were located on the right side, 15 (29%) on the left side, and 10 (19%) on the midline. In the immediate post operative period, 1 patient died (2.6%) and 8 patients (21%) presented various complications. The outcome at 6 months was: death 2.6%, moderately disabled 8%, good recovery 89%. The arguments in favour of, or against, the surgical treatment of unruptured aneurysms are discussed in view of the literature. In favour of prophylactic surgery are: 1) The rather poor overall outcome following aneurysm rupture (including deaths before admission); 2) The rather good outcome of surgery in published series of unruptured aneurysms. The data of the natural history of the unruptured aneurysm are more questionable: in this view, surgery seems to be recommended in young patients with an easily accessible aneurysm and being in a good clinical condition.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1992

Fenestration of the middle cerebral artery and aneurysm at the site of the fenestration.

The authors report the case of a patient who presented a ruptured aneurysm of the anterior communicating artery and an unruptured aneurysm of the middle cerebral artery arising at the site of a fenestration of the MCA. The fenestration was undiagnosed on the preoperative angiogram but discovered during the surgery carried out for clipping of the aneurysms. In the literature, cases of fenestration of the MCA are sporadically reported and are incidental findings; an aneurysm may be associated on an artery other than the fenestrated MCA; an aneurysm arising at the site of the MCA fenestration is a very rare occurrence.

Aneurysm, Ruptured↗

PubMed1992

[Ruptured intracranial aneurysm. Modification of the surgical method based on the state of consciousness and age of patients. Personal experience with 468 patients admitted during 2 periods (1972-84 and 1985-89)].

The management of the ruptured intracranial aneurysm (clinical grade I to IV only) is studied in a series including 140 patients admitted from 1985 through 1989, in which selected patients were submitted to early surgery and other patients were postponed for delayed surgery. The results are compared to those of an earlier series including 328 patients admitted from 1972 through 1984, for which the general attitude was the delayed surgery: in the later series; the selection for the timing of surgery was based on two main parameters: the clinical status and the patient's age. When we compare both series, the overall management results demonstrate an improvement of 10% of satisfactory results and a decrease of 10% in the death rate in favour of the later series; for the surgical results, the figures are respectively 6% and 5% in favour of the later series. The relationship between age and outcome shows a considerable improvement: over 50 years of age, we observed plus 25% of satisfactory results and minus 22% in death in favour of the later series. Similarly, the relationship between state of consciousness and outcome, demonstrated a great improvement: for drowsy and stuporous patients the figures are respectively plus 22% and minus 21% in favour of the later series. When we consider the later series alone, the patients were admitted at 4 intervals of time from S.A.H. (D0-3, D4-6, D7-15, D16 and over). The most favorable outcome was observed for those patients admitted late (after D7) and already stabilized.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1985

Modern method and instrument for measuring psychic performance.

This paper shows that cortical processing of information quantity can be given in bits, while speed of information processing can be given in bit/sec; therefore the information processing ability can be denoted in algebraical expression. Changes of emotional tension can be objectified by galvanic skin reflex and pulse reaction. This method and device is suitable to measure psychic state of space station personnel and to predict psychic activity.

Aerospace Medicine↗