[Ethylene glycol intoxication. Important differential diagnosis in comatose patients with metabolic acidosis]. / Athylenglykolintoxikation. Wichtige Differenzialdiagnose beim komatösen Patienten mit metabolischer Acidose.

Ethylene glycol is an alcohol, which is mainly used as antifreeze. Intoxication with ethylene glycol can cause neurological and cardiopulmonary symptoms, metabolic acidosis and acute renal failure. Therapeutic options include reversal of metabolic acidosis, inhibition of alcohol dehydrogenase and early hemodialysis. In survivors of the acute phase, lasting damage is rare. The case of a 49-year-old patient with ethylene glycol intoxication is reported which was characterized by progressive impairment of consciousness, tetraparesis, hyperventilation and metabolic acidosis.

Reduction in posterior cerebral artery blood flow velocity during caloric vestibular stimulation.

Transcranial Doppler (TCD) sonography was performed to assess the differential effects of caloric vestibular stimulation on cerebral blood flow (CBF) to the vestibular [middle cerebral artery (MCA)] and the visual [posterior cerebral artery (PCA)] cortices in 15 healthy volunteers with eyes closed. Caloric irrigation caused a sensation of rotation and nystagmus and not only increased velocity in the MCA (2.7 +/- 3.3%) but also, simultaneously, decreased velocity in the PCA (4.2 +/- 6.2%, p < 0.001 vs. MCA). CBF changes indicated by changes in velocity through the MCA and PCA may reflect functional deactivation of the visual cortex together with activation of the vestibular cortex: this beneficial multisensory interaction suppresses distressing oscillopsia.

Rotational vertebral artery occlusion syndrome with vertigo due to "labyrinthine excitation".

Leftward head rotations in a patient with a rotational vertebral artery occlusion syndrome elicited recurrent uniform attacks of severe rotatory vertigo and tinnitus in the right ear. These attacks were accompanied by a mixed clockwise torsional downbeat nystagmus with a horizontal component toward the right. A transient ischemia of the right labyrinth probably induced the attacks and led to a combined transient excitation of the right anterior and horizontal semicircular canals as well as the cochlea.

Near infrared spectroscopy (NIRS): a new tool to study hemodynamic changes during activation of brain function in human adults.

In healthy human adults, cerebral concentrations of oxygenated hemoglobin ([HbO2]) and deoxygenated hemoglobin ([HbR]) were assessed during brain activation using near infrared spectroscopy (NIRS). Measurements were made either in the frontal cortex (n = 10) during performance of cognitive tasks or in the occipital cortex (n = 6) during visual stimulation (flash-light exposure, picture observation). The typical findings during brain activation were an increase in [HbO2] and a decrease in [HbR]. We demonstrate that these findings are not due to alterations in skin blood flow. NIRS is a simple bedside technique for the assessment of hemodynamic alterations accompanying brain activation.

Noninvasive assessment of cerebral hemodynamics and tissue oxygenation during activation of brain cell function in human adults using near infrared spectroscopy.

Near Infrared Spectroscopy (NIRS) was employed to noninvasively and continuously (temporal resolution 0.5 s) assess changes in cerebral hemodynamics and oxygenation during various functional states of the adult human brain. During cognitive stimulation (performing calculations) a frontal increase in local cerebral blood volume and oxygenated hemoglobin concentration was observed in most (10 of 12) subjects. During visual stimulation (observing a picture) this was demonstrated in the occipital region in all three subjects. Deoxygenated hemoglobin either decreased, remained unchanged or slightly increased during these procedures. Epileptic patients were examined during spontaneously occurring complex-partial seizures. During these seizures extremely large increases in blood volume and oxygenated hemoglobin concentration were measured. In conclusion, this feasibility study indicates that NIRS might become a useful and simple bedside tool to assess brain function.

[Exophiala species--a rare cause of endocarditis with cerebral abscess formation]. / Exophiala-Spezies -- seltene Erreger einer Endokarditis mit zerebraler Abszedierung.

Exophiala species belong to the dematiaceous fungi. Occurring worldwide, they are a rare cause of human infection. We present the case of a 75-year-old immunocompetent patient with a cardiogenic embolic anterior cerebral artery infarction. Echocardiography revealed endocarditis of the aortic valve. Antibiotic therapy was initiated after susceptibility testing (blood cultures were positive for Staphylococcus aureus, and liquor was normal), with a subsequent fall in serologic markers of infection and resolution of the signs of endocarditis on echocardiography. However, 6 weeks after initiation of antibiotic therapy, abscesses were seen in the infarct region on CT scan, although antimicrobial treatment was still continued. At this stage, the CSF showed an inflammatory process, and Exophiala species, susceptible to voriconazol, could be detected in liquor cultures. However, antifungal therapy with voriconazol could not prevent severe sepsis and death from multiorgan failure. Autopsy revealed the clinically supposed Exophiala endocarditis with metastatic cerebral abscesses. In accordance with other published case reports, a fatal outcome in disseminated Exophiala infection might only be prevented by aggressive therapy consisting of early surgical removal of the foci and combined antifungal agents.

Single-fiber electromyography, nerve conduction studies, and conventional electromyography in patients with critical-illness polyneuropathy: evidence for a lesion of terminal motor axons.

Nine patients at risk for critical illness polyneuropathy (CIP) were included in a prospective study. We performed nerve conduction studies, electromyography, and a stimulation single-fiber electromyography (SFEMG). Five of 9 patients were diagnosed as CIP because they developed abnormal spontaneous activity during the follow-up period. Their SFEMG revealed a significant increase in mean jitter (25%, P < 0.005). In 4 patients without abnormal spontaneous activity there was no significant increase in the mean jitter, although 1 of the latter 4 patients showed an increased jitter, indicating that abnormal SFEMG may precede abnormal spontaneous activity. Nerve conduction studies did not show any significant changes in both patient groups. Our findings suggest that CIP is a primarily axonal motor neuropathy. The increased jitter in patients with CIP indicates that CIP is a primarily axonal neuropathy with a lesion of terminal motor axons.