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Biomedical subjects

M Feichtinger

Publications and source records attributed to M Feichtinger.

15 recordsLinked to original sources
PubMed2007

Removal of a pellet from the left orbital cavity by image-guided endoscopic navigation.

In the cranio-maxillofacial field, computer-aided surgery based on computed tomography data is becoming increasingly important. Complex surgical procedures can be performed utilizing preoperative imaging to provide real-time localization of surgical instruments in the surgical field. Image-data-based navigation plays an ever-increasing role in cases of minimal invasive surgery. The case is presented here of a 58-year-old male patient referred after a hunting accident with a pellet in the left orbit. After transferring the preoperatively acquired computed tomography data to a commercially available navigation system, the bullet was removed through the original wound canal using an intraoperatively calibrated high-resolution endoscope.

Endoscopes↗
PubMed2006

Cardiac metastasis after squamous cell carcinoma of the oral cavity: case report.

A 58-year-old woman presented with respiratory problems 6 months after she had had a squamous cell carcinoma in the oral cavity resected. We found on computed tomography a large lesion in the cardiac muscle. There were no abnormalities in the electrocardiogram. The patient died 7 days later and necropsy confirmed a solitary metastasis in the myocardium that originated from a squamous cell carcinoma of the mouth.

Carcinoma, Squamous Cell↗
PubMed2006

Extraosseous schwannoma of the mental nerve clinically simulating intraosseous.

We report a case of a benign neurilemmoma arising from the right mental nerve. Schwannomas are rare neurogenic tumours that originate from Schwann cells of the peripheral nervous system. Frequent locations are the head and neck region. Most of the tumours occur in the soft tissue whereas intraosseous schwannomas are rare. This case report deals with a young patient who was referred to our hospital with an unidentified fast-growing tumour located mainly in the premolar region of the right mandible. The tumour presented as an expansive, unilocular, well defined, radiolucent lesion on orthopantomography. No expansion of the mandibular canal could be seen. Computerized tomography scans of the mandible helped to identify the solid nature of the tumour. A biopsy was necessary to make the final diagnosis and the tumour was then excised surgically. Postoperative magnetic resonance imaging scans and a histological examination of the surgical specimen showed no signs of neurofibromatosis type 2.

Adolescent↗
PubMed2005

Ictal dystonic posturing in mesial versus neocortical temporal lobe seizures.

PURPOSE: Ictal contralateral dystonic posturing is a frequently observed clinical feature in temporal lobe seizures. It is generally interpreted as the result of spread of the ictal discharge into basal ganglia structure. In previous reports, analysing ictal behavior, a precise definition and description of the upper limb ictal dystonia is often lacking or contradictory. In our study we aimed to determine whether different subtypes of dystonia and their latency from the clinical onset of seizure might be of value for the differentiation between mesial temporal lobe epilepsy (MTLE) and neocortical temporal lobe epilepsy (NTLE). METHODS: Eighty seizures (51 MTLE and 29 NTLE) and 30 patients (20 MTLE and 10 NTLE) were analyzed with regard to dystonic posturing of the upper limb. Ictal dystonia was subdivided into different subtypes according to distinct clinical features. Their frequency and latency from the clinical onset of seizure were assessed. RESULTS: Frequencies of all subtypes were similar in MTLE and NTLE. Concerning the latencies contralateral dystonic posturing characterized by sustained muscle contractions with flexion of the wrist and fist closure, a frequently appearing feature, occurred significantly earlier in NTLE than in MTLE seizures. CONCLUSIONS: This difference between the two groups may provide a differentiation between an epileptic focus of mesial from neocortical temporal lobe origin.

Adult↗
PubMed2004

Comparison of clonidine to sleep deprivation in the potential to induce spike or sharp-wave activity.

OBJECTIVE: This study aimed to investigate previously observed side effects, i.e. increased epileptic activity during clonidine medication. The safety and effectiveness of clonidine as spike inducing agent compared to sleep deprivation were tested. METHODS: Patients suffering from drug-resistant localization related epilepsy took part in 3 magnetoencephalography (MEG) sessions. One session was recorded without any activating measures. The other two sessions were either performed after sleep deprivation or after medication with clonidine. Target parameter was the number of spikes or sharp-waves during a 30 min recording period. RESULTS: About 67% of the patients showed increased spike activity after clonidine, whereas sleep deprivation increased the number of spikes in 33%, and 29% of the patients did not show any activation at all. Clonidine was most effective in temporal lobe epilepsy, when the focus was located in the right hemisphere, and when clonidine serum concentrations were ranging between 0.6 and 1.0 ng/ml. CONCLUSIONS: This study showed for the first time that clonidine can be considered an effective spike or sharp-wave inducing drug that is superior to the potency of sleep deprivation. SIGNIFICANCE: The administration of clonidine increases the probability of recording ictal and interictal epileptic activity during limited acquisition time.

Action Potentials↗
PubMed2002

Future aspects of the presurgical evaluation in epilepsy.

Epilepsy surgery is a successful therapeutic approach in patients with medically intractable epilepsy. The presurgical evaluation aims to detect the epileptogenic brain area by use of different diagnostic techniques. In this review article the current diagnostic procedures applied for this purpose are described. The diagnostic armamentarium can be divided conceptually into three different groups: assessment of function/dysfunction, structural/morphologic imaging methods and functional neuroimaging techniques. Properties, diagnostic power and limits of all diagnostic tools used in the diagnostic evaluation are discussed. In addition, future perspectives and the diagnostic value of new technologies are mentioned. Some are increasingly gaining acceptance in the routine preoperative diagnostic procedure like MR volumetry or MR spectroscopy of the hippocampus in patients with temporal lobe epilepsy. Some, on the other hand, like MEG and 11C-flumazenil PET, still remain experimental diagnostic tools as they are technically demanding and cost intensive. Besides the refinement of established techniques, co-registration of different modalities like spike-triggered functional MRI will play an important role in the non-invasive detection of the epileptic seizure focus and may change the regimen of the preoperative diagnostic work up of epilepsy patients in the future.

Brain Diseases↗
PubMed2002

Gamma-Knife radiosurgery of mesiotemporal tumour epilepsy observations and long-term results.

PURPOSE: The efficacy of radiosurgery in cases of mesiotemporal tumours associated with long standing epilepsy has not clearly been documented up to now. The authors present a retrospective analysis of 19 cases treated by Gamma-Knife radiosurgery (GKRS) for mesiotemporal tumour epilepsy. METHODS: Between 1992 and 1997 19 patients (12 male and 7 female) with a mean age of 31 years (5-72) and mesiotemporal tumour-induced epilepsy of a mean duration of 8.6 years (0.9-28) were treated by GKRS. All tumours were within the mesiotemporal structures and the pathohistology proven by biopsy or resective procedure revealed 15 (79%) low grade astrocytomas, 3 (16%) gangliogliomas and 1 (5%) cavernoma. Beside tumour control, the main aim of GKRS was alleviation of epilepsy by irradiating the presumed epileptic foci outside the tumour volume. The 50% isodose volumes surrounding the tumours measured a mean of 6.2 ccm (1.1-18 ccm). Doses given at marginal isodoses ranged from 12 to 30 Gy (mean 17.3 Gy). The outcome with respect to epileptic seizures was evaluated by the Engel classification. RESULTS: After a follow-up (FU) of 1.7 to 9.7 years (mean 6.5 years) 11 patients (57.9%) were significantly ameliorated (Engel I and Engel II), 7 patients (36.8%) worthwhile improved (Engel III) and 1 patient (5.3%) unchanged. In 11 patients (58%) radiosurgically induced image changes were seen on MRI. INTERPRETATION: Although microsurgical approach guided by electrocorticography (EcoG) is the state of art for treatment of mesiotemporal tumour epilepsy, GKRS can be used as a non-invasive, safe and effective alternative to resective surgery for selected cases.

Adolescent↗
PubMed2002

Stereotactic radiosurgery for hypothalamic hamartomas.

Hypothalamic hamartomas are nonneoplastic lesions often characterized by central precocious puberty and gelastic epilepsy. Due to the delicate location surgery is often unsuccessful and associated with considerable risks. In the presented series, Gamma Knife radiosurgery was applied. Four cases (aged between 5-13 years) who presented with medically intractable gelastic epilepsy and increasing secondary generalization, abnormal behaviour and precocious puberty (3 cases) are reported. Hypothalamic hamartomas sized 11-17 mm had been diagnosed by MR imaging. Radiosurgical treatment was performed in general anaesthesia with margin doses of 12-14 Gy to the 50-90% isodoses covering volumes of 600-2300 mm3. After follow-up periods of 12 to 68 months, a continuing decrease both in seizure frequency and intensity was noted (outcome according to Engel: II a (3 cases) and III a (1 case)). All patients are socially reintegrated. MR imaging did not reveal significant changes concerning the size of the lesions. Gamma Knife radiosurgery can be an effective and safe alternative treatment modality for HH capable of achieving good seizure control and improving behavioural disorders in selected cases.

Adolescent↗
PubMed2002

[Goose flesh and cold sensation. Symptoms of visceral epilepsy].

Goose flesh and cold shiver can be ictal signs of visceral epilepsies. These visceral epilepsies may occur with isolated ictal signs during a simple partial seizure or in combination with other autonomic signs or in complex partial seizures. Because of the unusual features of the ictal symptomatology, these visceral epilepsies often are masked and wrongly diagnosed as nonepileptic events, e.g., somatoform disorders. Five cases are reported with case history, neurological findings, and results of electroencephalography, MEG, and imaging. Interestingly, patients did not suffer from tumoral epilepsies and the epileptic focus was lateralized to the left (dominant) temporal lobe.

Adolescent↗
PubMed2001

Ictal fear in temporal lobe epilepsy: surgical outcome and focal hippocampal changes revealed by proton magnetic resonance spectroscopy imaging.

BACKGROUND: Ictal fear (IF) is most frequently associated with epileptic discharges from mesial temporal areas. OBJECTIVES: To determine whether patients with IF were more likely to become seizure free after anteromesial temporal lobe resection compared with those without IF and whether they show more anteriorly pronounced metabolic changes assessed by means of multivoxel magnetic resonance spectroscopy (MRS) along the hippocampal axis. METHODS: Surgical outcome was assessed in 33 consecutive patients with temporal lobe epilepsy after a mean follow-up of 25 months (range, 12-38 months). Proton multivoxel MRS of the hippocampal formation was applied to detect regional differences along the axis of the hippocampus in patients with and without IF. Magnetic resonance tomography showed typical features of hippocampal sclerosis in all patients. RESULTS: Twelve (36%) of the 33 patients reported fear at the beginning of their habitual seizures. Eleven of these patients were seizure free postoperatively. In contrast, only 11 of 21 patients without IF had a favorable outcome. Results of MRS revealed significantly higher pathologic N-acetylaspartate-choline ratios in the anterior portion of the hippocampal formation in patients with than in those without IF, indicating focal metabolic and/or morphologic changes in the head of the hippocampus. CONCLUSIONS: These results indicate the importance of diagnosing auras with IF to provide a more detailed prognosis of the surgical outcome. In addition, our data emphasize that multivoxel MRS is a valuable tool in the presurgical evaluation, as it may reveal different topographical patterns of hippocampal sclerosis.

Adult↗
PubMed2001

Therapeutic intensive seizure analysis (TISA) in presurgical evaluation of Losigamone.

OBJECTIVE: The new method TISA was used to evaluate Losigamone efficacy. METHODS: Sixteen patients with pharmacoresistant partial seizures undergoing presurgical evaluation were randomized in this double-blind, placebo-controlled, parallel-group Losigamone monotherapy study under continuous video-EEG monitoring. Duration (in s, of each seizure and each ictal sign), intensity (grade zero to three), N/24h (number of seizures and ictal signs per 24 h), D/24h (seconds per 24 h covered by seizures and ictal signs) and seizure free intervals were recorded. RESULTS: A total of 246 seizures were intensively analyzed. The duration and intensity of all seizures improved more in the active treatment group than in the placebo group. There was a statistically significant superiority in the duration of the seizure free interval in the Losigamone group. Ictal signs such as oro-alimentary automatisms and fumbling were improved during Losigamone treatment. CONCLUSION: Losigamone has a preferred inhibitory effect on propagated epileptic activity. TISA is a sensitive method for evaluation of the selective effects of AEDs.

Adult↗
PubMed2001

Magnetic resonance spectroscopy and histopathological findings in temporal lobe epilepsy.

PURPOSE: In some patients with temporal lobe epilepsy, histopathological evaluation of resected brain tissue after surgical treatment may reveal several features indicative of discrete cortical malformations. We sought to determine whether these histopathological features were accompanied by hippocampal changes detectable preoperatively by proton magnetic resonance (MR) spectroscopy and to evaluate their relationship with postoperative outcome. METHODS: In 25 consecutive temporal lobe epilepsy patients who were scheduled for surgical treatment, MR spectroscopy was performed, and resected brain tissue was analyzed histopathologically for the presence of discrete cortical malformations (e.g., microdysgenesis). Outcome was assessed in all patients with an average postoperative period of 26 months. RESULTS: In 13 patients, we found subtle, histopathologically detectable signs of cortical malformation: 6 of them with concomitant hippocampal sclerosis (dual pathology) and 7 without. The latter subgroup had a worse surgical outcome and showed enhanced bilateral and/or contralateral pathological changes in the hippocampal formation when investigated by MR spectroscopy. CONCLUSIONS: These data suggest that by showing contralaterally or bilaterally abnormal spectra, MR spectroscopy might be able to indicate pathological changes in subtle developmental disorders that are possibly more widespread over the brain. This observation may improve noninvasive diagnosis in presurgical evaluation and the neurobiological understanding of cortical malformations in pharmacoresistant temporal lobe epilepsy.

Adult↗
PubMed1999

Is IgM of diagnostic value in case of delayed intrathecal production of IgG antibodies?

The neurological manifestations of Lyme borreliosis comprise a wide range of clinical signs. However, these symptoms might have other aetiologies. Therefore detection of intrathecal production of specific antibodies is necessary to confirm the clinical assumption of neuroborreliosis (NB). In case of delayed intrathecal production of specific IgG antibodies, detection of IgM could play a role in the early diagnosis of NB. To clarify whether IgM is of diagnostic value in such cases, paired CSF serum samples from 176 patients with suspected NB admitted to the department of Neurology, Karl Franzens University, Graz, Austria, were tested. Testing was performed with the IDEA Neuroborreliosis Kit (Dako, Denmark) and Enzygnost Borreliosis (Behring, Germany) and results of both methods were compared. According to well defined criteria 63 of the 176 patients had defined NB and 113 were regarded as possible NB. Twelve out of 63 patients with defined NB had delayed intrathecal IgG production. Only one patient with delayed IgG production had an intrathecal IgM production prior to IgG. In all patients with possible NB no intrathecal production of IgM was detected. At the time of the first lumbar puncture IgG intrathecal production could be detected with the IDEA seven times more often than with the Enzygnost Borreliosis. The determination of intrathecal production of IgM does not appear to be of diagnostic value in patients with delayed IgG antibody production. Therefore a consecutive lumbar puncture is more likely to confirm clinical assumption if there is strong clinical evidence of NB.

Adult↗