Acta neurochirurgica
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Acta neurochirurgica · Sep 2013
Case ReportsUnusual peroneal nerve palsy caused by intraneural ganglion cyst: pathological mechanism and appropriate treatment.
The origin of the peroneal intraneural ganglion and the outcome of treatment are still controversial. We report here three cases with peroneal intraneural ganglion and discuss the appropriate treatment. In our cases, 58-, 62-, and 65-year-old patients were operated on with extraneural decompression and epineurotomy within 4 months after onset of drop foot. ⋯ We propose correct early diagnosis, simple exoneural dissection, and atraumatic epineurotomy for the successful treatment of peroneal intraneural ganglion. Disruption of the stalk in the articular branch is a key point to prevent recurrence. For early diagnosis, clinicians should be aware of the existence of this rare lesion.
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Acta neurochirurgica · Sep 2013
Pathophysiology of shunt dysfunction in shunt treated hydrocephalus.
We hypothesized that shunt dysfunction in the ventricular catheter and the shunt valve is caused by different cellular responses. We also hypothesized that the cellular responses depend on different pathophysiological mechanisms. ⋯ The same cellular responses (i.e., glial cells and inflammatory cells) cause both catheter obstruction and valve obstruction. We propose two synergistic pathophysiological mechanisms. (1) Ventricle wall/parenchymal contact by the catheter causes mechanical irritation of the parenchyma including ependymal exfoliation. (2) The shunt material provokes an inflammatory reaction, either nonspecific or specific. In combination, these mechanisms cause obstructive tissue ingrowth (glial and inflammatory) in the catheter and clogging of the valve by exfoliated glial cells and reactive inflammatory cells.
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Acta neurochirurgica · Aug 2013
Decreased inhibitory neuronal activity in patients with frontal lobe brain tumors with seizure presentation: Preliminary study using magnetoencephalography.
Although 30-50 % of patients with brain tumors experience epileptic seizure as the presenting clinical symptom, and another 10-30 % are at risk for developing epilepsy in the later stages of the disease, the mechanisms of tumor-related epileptogenesis are poorly understood. We used magnetoencephalography (MEG) to investigate sensory evoked fields (SEFs) in patients with frontal lobe brain tumors as a means of evaluating the neuronal activity of peri-tumoral cortex. ⋯ The paradoxical increase in P35m/N20m in patients with seizure presentation suggests that decreased inhibitory neuronal activity is a potential cause of tumorrelated epilepsy.
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Acta neurochirurgica · Aug 2013
Case ReportsChanges in wall shear stress magnitude after aneurysm rupture.
Computational fluid dynamics (CFD) studies on cerebral aneurysms have attempted to identify surrogate hemodynamic parameters to predict rupture risk. We present a case of bilateral mirror image aneurysms, one of which ruptured soon after imaging. ⋯ Findings from our case suggest that CFD studies comparing unruptured and ruptured aneurysms may not yield valid estimation on aneurysm rupture risk because of changes in aneurysm shape after rupture. Changes in aneurysm shape after rupture should be considered in CFD research.