Biomedical subjects

K Grosser

Publications and source records attributed to K Grosser.

6 recordsLinked to original sources

PubMed2000

Olfactory and trigeminal event-related potentials in migraine.

BACKGROUND: Trigeminal/neuronal hyperexcitability and spreading depression activating the trigemino-vascular system are discussed in migraine-pathophysiology. This study investigated trigeminal and olfactory event-related potentials in migraineurs. METHODS: Nasal chemosensitivity was assessed in 19 female migraineurs with or without aura > 72 h before or after an attack and in 19 healthy females employing event-related cortical potentials (ERPs) after specific trigeminal stimulation of nasal nociceptors with short pulses of CO2, and specific olfactory stimulation with H2S. Odour thresholds and odour identification performance were also tested. RESULTS: Migraineurs exhibited greater responses to trigeminal stimulation, indicated by significantly larger ERP amplitudes N1. In contrast, olfactory ERP amplitudes P1N1 were significantly smaller in migraineurs. A leave-one-out classification procedure on the basis of these two parameters assigned 76.3% cases correctly. The olfactory ERP amplitude discriminated better between groups than trigeminal ERPs (71.1 vs. 68.4% correct classification). CONCLUSIONS: Our data suggest trigeminal hyperexcitability in migraineurs. A general increase of nasal chemosensitivity is not supported because of smaller olfactory ERP amplitudes in migraineurs. Olfactory ERPs discriminate better than trigeminal ERPs between migraineurs and controls, emphasizing the significance of the olfactory system in migraine.

Adult↗

PubMed1999

Visual evoked potentials in migraine patients: alterations depend on pattern spatial frequency.

Visual information is conducted by two parallel pathways (luminance- and contour-processing pathways) which are thought to be differentially affected in migraine and can be investigated by means of pattern-reversal visual evoked potentials (VEPs). Components and habituation of VEPs at four spatial frequencies were compared between 26 migraineurs (13 without aura, MO; 13 with aura, MA) and 28 healthy volunteers. Migraineurs were recorded in the headache-free interval (at least 72 h before and after an attack). Five blocks of 50 responses to chequerboards of 0.5, 1, 2 and 4 cycles per degree (c.p.d.) were sequentially averaged and analysed for latency and amplitude. Differences in VEPs were dependent on spatial frequency. Only when small checks were presented, i.e. at high spatial frequency (2 and 4 c.p.d.), was the latency of N2 significantly prolonged in MA and did it tend to be delayed in MO subjects. Habituation behaviour was not significantly different between groups under the stimulating conditions employed. Prolonged N2 latency might be explained by the lack or attenuation of a contour-specific component N130 in migraineurs, indicating an imbalance of the two visual pathways with relative predominance of the luminance-processing Y system. These results reflect an interictally persisting dysfunction of precortical visual processing which might be relevant in the pathophysiology of migraine.

Adult↗

PubMed1998

Olfactory function in acute rhinitis.

This study was performed to investigate the effects of the common cold on olfactory function, which was assessed using chemosensory event-related potentials (CSERP, in response to both olfactory [H2S] and trigeminal [CO2] stimuli) and psychophysical measures (intensity ratings, odor discrimination, butanol threshold); nasal volume was assessed by means of acoustic rhinometry. The investigation was performed in 36 subjects (18 women, 18 men). After onset of the rhinitis (day 0) measurements were performed on days 2, 4, 6 and 35. The cold produced a decrease of the volume of the anterior nasal cavity accompanied by an increase of mucus secretion, an increase of olfactory thresholds, a decrease of intensity ratings and a decrease of N1 CSERP amplitudes to olfactory and trigeminal stimuli. When mucus secretion of the contralateral nasal cavity was controlled with oxymetazoline, N1 amplitudes to olfactory stimuli were still affected by the cold as indicated by the significant increase of amplitudes as subjects recovered; this phenomenenon was not found for responses to trigeminal stimuli. This indicates that the common cold has a small effect on olfactory function which may be independent of nasal congestion.

Acute Disease↗

PubMed1998

Laparoscopy-assisted abdominal shunt revisions in children with hydrocephalus.

Abdominal shunt revisions are frequently necessary for ventriculoperitoneal shunt systems in children with hydrocephalus internus. There are many well-known problems related to abdominal shunt revisions such as difficulties in reaching the abdominal cavity, intra-abdominal adhesions, cerebrospinal fluid pseudocyst, or problems in retrieving dislocated catheters. From 6/1996 to 12/1997 we operated on twenty (20) children aged from 2-15 years (body weight 4.8-68 kg) with abdominal shunt insufficiency using the laparoscopy assisted technique. In only one case was it impossible to reach the abdominal cavity laparoscopically and conventional open surgery was necessary. We had no complications such as injured vessels or bowel and saw a complete recovery in all patients. In comparison to conventional surgery, we found handling simple, minor trauma to the patients, good intra-abdominal view, short operation times and good cosmetic results to be the advantages of laparoscopy-assisted abdominal shunt revision. In addition hospitalisation time can be reduced.

Adolescent↗

PubMed1997

Association between thrombolytic treatment and the prognosis of hemodynamically stable patients with major pulmonary embolism: results of a multicenter registry.

BACKGROUND: Thrombolytic treatment has been shown to accelerate resolution of major pulmonary embolism and lead to a rapid improvement of right-side hemodynamics. However, the association between these favorable effects and the clinical outcome of patients who have no severe hemodynamic compromise at presentation remains unknown. METHODS AND RESULTS: The present multicenter registry included 719 consecutive patients with major pulmonary embolism according to clinical, echocardiographic, scintigraphic, and cardiac catheterization criteria. Symptom onset was acute (<48 hours) in 63% of patients. All patients were hemodynamically stable (ie, without evidence of cardiogenic shock) at presentation. Primary thrombolytic treatment (within 24 hours of diagnosis) was given to 169 patients (23.5%), whereas the remaining 550 patients were initially treated with heparin alone. Overall 30-day mortality was significantly lower in the patients who received thrombolytic agents (4.7 versus 11.1%, P=.016). Clinical factors associated with a higher death rate were syncope (P=.012), arterial hypotension (P=.021), history of congestive heart failure (P=.013), and chronic pulmonary disease (P=.032). However, only primary thrombolysis was found by multivariate analysis to be an independent predictor of survival (odds ratio for in-hospital death, 0.46; 95% confidence interval, 0.21 to 1.00). Patients who underwent early thrombolytic treatment had a reduced rate of recurrent pulmonary embolism (7.7 versus 18.7%, P<.001) but also a higher frequency of major bleeding episodes (21.9% versus 7.8%, P<.001). Cerebral bleeding occurred in 2 patients in each treatment group, and 1 patient in each group died of a bleeding complication. CONCLUSIONS: The results of our study suggest that thrombolysis may favorably affect the clinical outcome of hemodynamically stable patients with major pulmonary embolism.

Adolescent↗

PubMed1997

[Does MRI compared with ultrasound examination add therapy-relevant knowledge in anorectal abnormalities?].

The topographical situation of the blind end of the recto-anal atresia to the musculus levator ani is the main question to ask when deciding on any operative procedure and for the prognosis of continence. In neonates, the use of preoperative perineal ultrasound is sufficient rather than magnetic resonance imaging in establishing the surgical way. In older incontinent children after pullthrough procedure, magnetic resonance imaging has benefits over endorectal ultrasound, especially in presenting muscular and cicatricial relationships.

Anus, Imperforate↗