Life expectancy and causes of death in a group of head-injured veterans of World War I.

The life spans and causes of death were examined for a group of Bavarian veterans of World War I who had suffered head injuries and for comparable control subjects who had not. The occurrence of posttraumatic fits was a significant prognostic factor for a higher death rate after the age of 50 years. Other indicators of the severity of injury did not lead to differences in the death rates. There were significantly more deaths due to cerebrovascular causes in the head-injured group than in the control group, but no subgroup was found to have significantly more cerebrovascular deaths than any other.

Somatosensory tibial nerve evoked potentials with parasagittal tumours: a contribution to the problem of generators.

Somatosensory evoked potentials following stimulation of the median nerve at the wrist and the tibial nerve at the ankle were recorded in 5 patients with parasagittal tumours, 4 in the fronto-parietal and 1 in the frontal region. Three had intracerebral tumours and 2 parasagittal meningiomas. The extent of each lesion was determined by CT scan, showing a unilateral process involving predominantly the paracentral lobule and adjacent parts of the post- and precentral gyri ("Mantelkante') in 4 patients and a more frontal location of one meningioma affecting mainly the superior frontal gyrus. SEPs recorded from the patients with fronto-parietal tumours showed a uniform pattern with a complete absence of the wave N70 of the tibial SEP elicited by stimulating the nerve contralateral to the lesion. All other waves, including the P40-N50 complex on both sides and the median SEP, were in the normal range. In contrast, the frontal meningioma led to an only slightly altered from of the waves immediately following the initial P40-N50 complex. It is concluded that the tumour abolished the generators of the wave N70 which are apparently located in the cortical somatosensory leg area. Therefore unilateral loss of the wave N70 is indicative of parasagittal lesions. The results may give good evidence that the P40-N50 complex is generated in the thalamus or thalamo-cortical connections.

The angiographic diagnosis of occlusions of the posterior cerebral artery.

The angiographic appearance of twenty-seven unilateral or bilateral occlusions of the posterior cerebral artery (PCA) are described. They are classified into proximal, interpeduncular, ambient or distal occlusions according to their prefered location. Ambient occlusions were by far the most common and have therefore probably not developed from a stenosing arteriosclerosis since this forms preferentially in the proximal and interpeduncular segment. Leptomeningeal anastomoses were common between all respective branches of the middle cerebral artery and the PCA but the anterior cerebral artery and the interarterial anastomoses rarely contributed to the collateral blood supply. A retrograde progression of the occlusion was observed on reangiography occasionally in cases in which there was no major artery originating just proximal to the occlusion. Anterograde progression and disintegration of obstructing material was also observed. PCA occlusions had a good prognosis in terms of survival but the associated visual field defects rarely improved.