Chapter XII: Temporal Expanding Processes, Including Those in the Sylvian Fissure and the Insula

Transcription

1 Acta Radiologica ISSN: (Print) (Online) Journal homepage: Chapter XII: Temporal Expanding Processes, Including Those in the Sylvian Fissure and the Insula To cite this article: (1954) Chapter XII: Temporal Expanding Processes, Including Those in the Sylvian Fissure and the Insula, Acta Radiologica, 41:sup107, , DOI: / To link to this article: Published online: 14 Dec Submit your article to this journal Article views: 17 Full Terms & Conditions of access and use can be found at

2 CHAPTER XI1 Temporal Expanding Processes, Including Those in the Sylvian Fissure and the Insula A. The Arteries In expanding processes lying anteriorly in the lateral part of the middle cranial fossa, typical features are an upward displacement of the middle cerebral artery and a curved deflection upwards, or forwards and upwards, of its branches in the Sylvian fissure. When the process is situated more posteriorly, the middle cerebral artery is affected to a lesser extent or not at all, although its branches in the Sylvian fissure are displaced in the upward direction. Expanding processes lying far back in the temporal lobe sometimes invade the parietal or occipital lobe. The arterial displacement then shows a combination of the changes resulting from expanding processes in the respective lobes. Tumours lying in the Sylvian fissure lead to either upward or downward deflection of the arteries of the Sylvian group, depending on whether the process is situated below or above them. Some vessels may be more displaced than others andconsiderably stretched or compressed. Medial displacement of the arteries of the Sylvian group is also found. With temporal expanding processes, the arteries in the longitudinal fissure are almost invariably pushed across the midline. The expanding process may affect the different arteries to a varying degree or, if it is extremely large, to about the same degree. In deep-seated turnours, the posterior temporal artery is almost constantly less displaced than the other arteries of the Sylvian group. In tumours situated anteriorly and reaching or lying medially, the carotid siphon may be stretched and the anterior choroid artery deflected, usually upwards. If the posterior cerebral artery is filled, it may be seen to be displaced in a downward curve in the presence of such processes. It can, however, be difficult to judge whether there is actually a displacement, since the usual pattern of the artery varies and it sometimes forms a curve, convex downwards. B. The Central Veins and Deep Dural Sinuses Earlier Observations In a deep tumour ( tiefer Tumor ) of the middle cranial fossa, MONIZ found upward displacement of both the internal cerebral and the basal vein. WICKBOM wrote: Sometimes the basilar vein may be affected if the tumour lies sufficiently far medially. This observation was also made by LIMA. In a highly vascular tumour of the temporal lobe, extending towards the corpus caliosum, UMBACH found compression and elevation of the basal and the internal cerebral veins; in addition, the straight sinus was elevated ( aufgerichtet ). LORENZ reported that, with temporal tumours, the internal cerebral vein could lie more basally than usual and that the great cerebral vein could lose its semicircular shape and become straightened. I22

3 CURTIS was able to identify the internal cerebral vein in the lateral view in 23 out of 39 temporal and temporal-occipital tumours; he found it to be displaced upwards in 7 of the cases. SCHURR studied a series of temporal abscesses and observed in the a-p projection a shift of the anterior cerebral artery to the opposite side and in many cases a shift of the great vein of Galen in the same direction. Present Observations My observations were made on 15 cases. In 3 cases the expanding process involved the whole or the greater part of the temporal lobe, in 6 its anterior part and in 2 its posterior part. In I case the tumour lay subtemporally and anteriorly, in 2 cases in the Sylvian fissure and in I in the insula. Pneumography was performed in all except 3 cases. The presence of the expanding process was verified at operation in every case. An account of the findings at pneumography and of the arterial displacement in each of the cases is given in the case reports. In none of the cases did the appearance or position of the inferior longitudinal and straight sinuses differ from the variations described in the chapters on normal anatomy. Consequently, there was no reason to conclude that they were displaced. Expanding Processes Involving the Greater Part of the Temporal Lobe In temporal expanding processes, the most constant finding was displacement of the basal vein. In the 3 cases in which the tumour involved the whole or the greater part of the temporal lobe, this vein was dislocated medially. In z of the cases (Nos. 58, 60) it was also stretched and shifted downwards. This downward and medial displacement of the basal vein implies that the medial margin of the temporal lobe is pushed over the free margin of the tentorium; it is thus an indication of tentorial herniation. The internal cerebral vein was pushed across the midline and in one of the cases (No. 60) it was also elevated. The sideward displacement of this vein was less than that of the basal vein, which lay closer to the tumour. In I case (No. 58) the arteries in the longitudinal fissure lay in the midline. In the other 2, they were pushed across the midline but to a lesser extent than the internal cerebral vein. The displacement of the arteries in the Sylvian fissure left no doubts regarding the localization of the expanding process to the temporal lobe. The depth of the Sylvian fissure varies and the arteries of the Sylvian group indicate the position of the boundaries of the temporal lobe mainly in the lateral and upward directions. The basal vein and the posterior cerebral artery accompany each other for part of their course and indicate the extent of the temporal lobe in the medial direction. In none of my cases under discussion was the posterior cerebral artery filled. The basal vein, on the other hand, was filled. In carotid angiography with the routine method, this vein is more frequently

4 filled with contrast medium than is the posterior cerebral artery. Consequently, the basal vein can deputize as an indicator of the position of the medial part of the temporal lobe. Anterior Temporal Expanding Processes As I showed in the chapters on normal anatomy, the posterior part of the basal vein runs dlrectly medial to the medial margin of the temporal lobe, whereas its anterior part lies medially above this lobe (above its uncus). Consequently, it is easy to understand the position and appearance of the basal vein in expanding processes lying in the anterior part of the temporal lobe or subtemporally and anteriorly. In my cases (Nos ) the anterior part of the basal vein was displaced upwards and with one exception (No. 62) medially as well. ln Case 62, a congenital glioma of the temporal pole, lateral displacement of the internal cerebral vein and of the arteries in the longitudinal fissure was also lacking. In every case in which the basal vein was displaced medially, the internal cerebral vein was pushed across the midline, in the same direction as the basal vein but to a lesser degree. In only 2 cases (Nos. 63, 65) was the anterior part of theinternal cerebral vein shifted upwards. As compared to the arteries in the longitudinal fissure, the internal cerebral vein was displaced farther across the midline, except in one case (No. 6j) in which the degree of displacement was approximately the same. In none of these cases was the posterior cerebral artery filled. In 6 cases (Nos ) the anterior choroid artery was stretched. In I of them (No. 62) it ran in an upward convex curve and in another (No. 64) its posterior part was elevated. The pattern of the basal vein complemented the information provided by the appearance of the arteries. Medial displacement of the basal vein was present not only when the expanding process was situated laterally (No. 61) but also when it occupied the whole or the greater part of the breadth of the temporal lobe (Nos ) and when it involved the whole breadth of the lateral part of the middle cranial fossa. Consequently, displacement of the vein in the medial direction only does not indicate the extension of the process. A common feature of all the tumours extending medially to the anterior part of the basal vein was its local deformation. In the subtemporal tumour (No. 67), a highiy vascular meningeoma, the basal vein was thicker than usually, indicating an increased blood flow. Posterior Temporal Expanding Processes In expanding processes in the posterior part of the temporal lobe (Nos. 68, 69) the basal vein was displaced medially and its posterior part slightly upwards as well. The latter change may be difficult to assess; when its presence is suspected, it is suitable to compare the course of the basal vein in the two hemispheres. The internal cerebral vein was pushed across the midline; in I case it was also elevated. The degree of displacement sidewards was about the same as that of the basal vein.

5 Compared to the arteries in the longitudinal fissure, the internal cerebral vein was pushed across the midline to about the same degree in one case and to a greater degree in the other. The position of the expanding process could be determined partly with the help of the appearance of the arteries and partly (in the medial direction) with that of the basal vein. As pointed out earlier, upward displacement of the posterior part of the basal vein may be caused by an infratentorial expanding process. It may also be a result of an expanding process which, from a posterolateral direction in the parietal or occipital lobe, extends from below towards the lateral ventricle. In the former case there is usually symmetric hydrocephalus with downward and backward displacement of the internal cerebral vein but no lateral shift. In the latter, there is displacement of the internal cerebral vein beyond the midline. This, together with the appearance of the arteries, may be used as a basis for distinguishing between the respective localizations of the tumours. Expanding Processes in the Sylvian Fissure In z cases (Nos. 70, 71) the expanding process lay in the Sylvian fissure. The basal vein was shifted medially. In one of them (No. 70) the tumour originated in the dura, at the pterion. In the other (No. 71) the tumour was situated more posteriorly; the posterior part of the basal vein was stretched in a curve, convex medially, and the internal cerebral vein was pushed across the midline more than the arteries in the longitudinal fissure. In the former case, on the other hand, the sideward displacement of these arteries was slightly greater than that of the internal cerebral vein, whereas that of the internal cerebral and basal veins was of about the same degree. Expanding Process of the Insula It may be inferred from the aforegoing that it was often possible to delimit an expanding process with the help of the central veins in addition to the arteries. Its position could then be determined with greater accuracy than when the appearance of the arteries alone was used. This also applies to Case 72, although in this instance the pattern of the central veins was sufficient to indicate the exact localization. The basal vein was deflected medially and slightly downwards. The internal cerebral vein was pushed across the midline and slightly upwards. Its sideward displacement was about the same as that of the basal vein but greater than that of the arteries in the longitudinal fissure. The arteries in the Sylvian fissure were displaced slightly in the lateral direction; anteriorly, some of them were separated. Consequently, the expanding process could be delimited between the arteries in the Sylvian fissure, the basal vein and the internal cerebral vein. Its exact position was, however, indicated by the veins coming from the insula. They were distinctly thicker than usually, denoting an increased blood flow from the insula.

6 Summary The basal vein is usually displaced medially. With large expanding processes, involving the whole or the greater part of the temporal lobe, it is apt to be shifted downwards as well. The anterior part of the vein is deflected upwards when the tumour lies anteriorly. When the process is situated in the posterior part of the temporal lobe, the posterior part of the basal vein is shifted both upwards and medially. As a rule, the internal cerebral vein is pushed across the midline. Its displacement sidewards is usually slightly less than that of the basal vein but greater than that of the arteries in the longitudinal fissure. The difference between the lateral displacement of the internal cerebral vein and that of the arteries in the longitudinal fissure and its importance for the localization of expanding processes in the sagittal direction has been discussed earlier (Chaps. X and XI). It is found to apply to the localizations dealt with in this chapter as well. The change in the appearance and position of the basal vein is, however, of greater consequence. Conclusions In temporal expanding processes, including those in the Sylvian fissure and the insula, the pattern of the central veins gives additional information to that provided by the arteries. In particular, the position of the process is indicated by a shift of the basal vein medially, upwards or downwards. Medial extension of the process may be indicated by local deformation of the basal vein or its displacement upwards. The expanding process can often be delimited as lying between the middle cerebral artery and its branches and the basal vein. Case Reports Expanding Process bvoluing the Greater Part of the Temporal Lobe Case ~8.-Astrocytoma of the right temporal lobe. E-y: Displacement of the lateral ventricles and the 3rd ventricle to the left; no oblique position of the septum lucidum. The right temporal horn is very slightly displaced medially; it is flattened from the lateral direction and from above and its middle part is depressed. Arteries: No definite displacement of the arteries in the longitudinal fissure. Upward and medial deflection of the arteries of the Sylvian group; stretching of their anterior parts. Stretching and separation of their branches running downwards and laterally from this site. Central veins: Displacement of the internal cerebral vein to the left. Medial deflection of the basal vein, thus in the same direction as that of the internal cerebral vein but more marked. The basal vein is also stretched in a curve, convex downwards; posteriorly, the curve is convex medially as well. Case ~9.-Astrocytoma of the left temporal lobe. Fig. 57. E-y: Displacement to the right of the lateral ventrides and the 3rd ventricle; the septum lucidum and the 3rd ventricle form an angle, open to the left. The trigone of the left lateral ventricle and the posterior part of its body, as well as the posterior part of the temporal horn, are grossly deformed and narrowed by irregular bulges. 126

7 Fig. 57. Case 19. Arteries: Displacement to the right of the arteries in the longitudinal fissure. Curved upward and forward deflection of the arteries of the Sylvian group. Central veins: Displacement to the right of the internal cerebral vein, somewhat greater than that of the arteries in the longitudinal fissure. Displacement of the basal vein in the same

8 direction as the internal cerebral vein but to a greater extent; no definite upward or downward deflection. Case 6o.-Glioma of the right temporal lobe. Fig. 38. V-y: Displacement to the left of the lateral ventricles and the 3rd ventricle; the septum lucidum and the 3rd ventricle form an angle, open to the right. The displacement is greatest behind the interventricular foramen. In the trigone and body of the right lateral ventricle, a bulge from below. The right temporal horn is slightly deflected downwards and is partly compressed by a bulge from above. Arteries: Displacement of the arteries in the longitudinal fissure to the left. The curve of the pericallosal artery is greatly widened. Considerable curved, upward deflection of the arteries of the Sylvian group, most marked anteriorly. Central veins: The internal cerebral vein is elevated; it is also displaced to the left, more than the arteries in the longitudinal fissure. Medial displacement of the basal vein; thus in the same direction as that of the internal cerebral vein, but to a considerably greater degree. The basal vein is also stretched and shifted downwards. Anterior Temporal Expanding Processes Case 61.-Astrocytoma situated laterally in the right temporal pole. Fig. 39. E-y: Displacement of the lateral ventricles a few mm to the left; the right lateral ventricle is slightly compressed laterally from below. The right temporal horn is displaced medially, backwards and upwards. Its lateral cleft is flattened from below and laterally. Arteries: Anteriorly, very slight curved displacement to the left of the arteries in the longi- Fig. 58. Case 60. I28

9 Fig. 59. Case 61. tudinal fissure. The middle cerebral artery and the arteries in the anterior part of the Sylvian fissure are deflected upwards. No filling of the posterior cerebral artery. Central veins: Displacement to the left of the internal cerebral vein, slightly more than that of the arteries in the longitudinal fissure. Elevation and medial deflection of the anterior part of the basal vein, thus in the same direction and to about the same extent as that of the internal cerebral vein. Case Congenital glioma of the right temporal pole. E-y: Displacement of the lateral ventricles a few mm to the left. The right temporal horn is displaced backwards and upwards and flattened in the anteroposterior direction. Arteries: Anteriorly, the arteries of the Sylvian group are displaced upwards and medially. The branches running laterally and downwards from this site are slightly stretched. Deflection of the anterior choroid artery in a curve, convex upwards. No filling of the posterior cerebral artery. Central veins: Elevation of the anterior part of the basal vein. 9-.?041.?4 1-29

10 Case 6j.-Secondary tumour, barely 4 cm in diameter, of the right temporal pole. Arteries: Slight displacement to the left, most marked anteriorly, of the arteries in the longitudinal fissure. Elevation of the middle cerebral artery and of its branches in the Sylvian fissure, the last-mentioned in a curve. Stretching of the anterior choroid artery. No filling of the posterior cerebral artery. Central veins: Displacement of the internal cerebral vein to the left, slightly more than that of the arteries in the longitudinal fissure; it is also elevated anteriorly. Anteriorly, the basal vein is also lifted, as well as displaced medially; thus in the same direction as the internal cerebral vein but considerably more. Case 64. -Oligodendroglioma, about 5 cm in diameter, of the left temporal pole. E-y: Displacement to the right, greatest anteriorly, of the lateral ventricles and the 3rd ventricle; no oblique position of the septum lucidum. Slight upward displacement of the superior lateral corner of the left lateral ventricle. The left temporal horn is shifted backwards and upwards and flattened from in front. Arteries: Displacement of the arteries in the longitudinal fissure a few mm to the right. Medial and upward deflection of the middle cerebral artery. Anteriorly, curved upward displacement of the arteries in the Sylvian fissure. Stretching of the anterior choroid artery and elevation of its posterior part. No filling of the posterior cerebral artery. Central veins: Displacement of the internal cerebral vein to the right, slightly more than that of the arteries in the longitudinal fissure. Elevation and deformation of the anterior part of the basal vein. The vein is also deflected medially, thus in the same direction as the internal cerebral vein but to a greater degree. Case 6j. -Astrocytoma of the right temporal pole, invading structures lying medially to the temporal lobe. Fig. 60. Arteries: Displacement to the left, greatest anteriorly, of the arteries in the longitudinal fissure. The middle cerebral artery and the arteries in the anterior part of the Sylvian fissure are Fig. 60. Case 65.

11 slightly elevated in a curve. Stretching of the anterior choroid artery. No filling of the posterior cerebral artery. Central veins: The internal cerebral vein is displaced to the left to about the same degree as the arteries in the longitudinal fissure; its anterior part is also elevated. Considerable deformation of the basal vein. There is angulated elevation of its anterior extremity as well as medial displacement; thus in the same direction as that of the internal cerebral vein but considerably more marked. Case 66.-Glioma, about 5 cm in diameter, in the anterior two-thirds of the right temporal lobe. V-y: No air in the right lateral ventricle. Displacement of the left lateral ventricle and the 3rd ventricle to the left. The septum lucidum and the 3rd ventricle form an angle, open to the right. Arteries: Anteriorly, displacement to the left of the arteries in the longitudinal fissure; the curve of the pericallosal artery is widened. Medial displacement and curved elevation of the middle cerebral artery. The arteries in the Sylvian fissure are lifted in a curve and some of them are separated. Stretching of the anterior choroid artery. No filling of the posterior cerebral artery. Central veins: Displacement to the left of the internal cerebral vein, considerably greater than that of the arteries in the longitudinal fissure. Irregular deformation of the basal vein; it is elevated anteriorly and displaced medially, thus in the same direction as the internal cerebral vein but to a far greater degree. Case 67.-Highly vascular meningeoma, broadly adherent to the floor of the middle cranial fossa on the right side (subtemporally) and occupying the whole of its anterior part. The turnout extends approximately to the level of the superior surface of the lesser wing of the sphenoid bone. Fig. 61. Fig. 61. Case 67.

12 E-y: Only the left lateral ventricle and the 3rd ventricle are filled with air; they are displaced to the left, most anteriorly. Arteries: The superior part of the carotid siphon is narrow; it is displaced forwards and medially. The anterior cerebral artery on the right side is not filled, despite compression ofthe left common carotid during injection. Elevation of the middle cerebral artery; gross forward and upward displacement of its branches in the Sylvian fissure. Considerably less deflection of the posterior temporal artery than of the other branches. Stretching of the anterior choroid artery. No filling of the posterior cerebral artery. Central veins: Displacement of the internal cerebral vein to the left. Anteriorly, the basal vein is elevated. It is also displaced medially, thus in the same direction as the internal cerebral vein but to a greater degree. The basal vein is thicker than usually, indicating an increased blood flow from the area drained by it. Posterior Temporal Expanding Processes Case 68. -Astrocytoma of the left temporal lobe, lying posteriorly below the temporal horn. Fig. 62. V-y: Displacement to the right of the lateral ventricles and the 3rd ventricle. The septum lucidum and the 3rd ventricle form a very slight angle, open to the left. Marked displacement Fig. 62. Case 68.

13 in a forward and upward curve of the temporal horn, the posterior horn and the trigone of the left lateral ventricle. In the postero-inferior part of the left temporal horn, a rounded bulge. Arteries: Displacement to the right, greatest anteriorly, of the arteries in the longitudinal fissure. Slight upward deflection of the arteries in the Sylvian fissure, particularly of the posterior temporal artery. Central veins: The internal cerebral vein is displaced to the right to approximately the same degree as the arteries in the longitudinal fissure. Medial deflection of the basal vein; thus in the same direction as that of the internal cerebral vein and to about the same degree. Elevation of the posterior part of the basal vein (cf. the contralateral vein). Case 69.-Glioma, about 5 cm in diameter, lying posteriorly in the right temporal lobe. V-y: Only the left lateral ventricle is filled with air; it is displaced to the left, its posterior part being most affected. A curved bulge from the right in the medial wall of its body. Arteries: Displacement to the left of the arteries in the longitudinal fissure. The arteries in the Sylvian fissure are elevated with the exception of the posterior temporal artery which, like the posterior cerebral artery, is shifted downwards instead. The area formed by the curved separation of these arteries is mainly avascular, but a number of arteriovenous fistulae are present in its superior part. Central veins: The internal cerebral vein is elevated and displaced to the left, more than the arteries in the longitudinal fissure. Medial displacement of the basal vein, thus in the same direction as that of the internal cerebral vein and to about the same degree. Considerable deformation of the posterior part of the basal vein and deflection forwards, upwards and medially. Expanding Processes in the Sylvian Fissure Case To.--Meningeoma about 2.5 cm in diameter, arising in the dura at the pterion on the right side and causing separation of the Sylvian fissure. E-y: Displacement of the lateral ventricles and the 3rd ventricle to the left. The septum lucidum is vertical and forms an angle, open to the right, with the 3rd ventricle. Sharpening of the angle of the superior lateral corner of the right lateral ventricle, which is partly pushed below the falx. The right temporal horn is displaced medially and very slightly elevated. Arteries: Displacement to the left, greatest anteriorly, of the arteries in the longitudinal fissure. The arteries in the anterior part of the Sylvian fissure are considerably deflected medially and slightly elevated; their anterolateral branches are stretched. Central veins: Displacement to the left of the internal cerebral vein, very slightly less than that of the arteries in the longitudinal fissure. The basal vein is deflected in the same direction as the internal cerebral vein and to about the same degree. Case 7r.-Oligodendroglioma in the middle part of the left Sylvian fissure. Arteries: Curved displacement to the right, greatest at the level of the bregma, of the arteries in the longitudinal fissure. In the Sylvian fissure, the arteries are displaced around an expanding process about 3 cm in diameter; the ascending branches are slightly stretched. Central veins: Displacement to the right of the internal cerebral vein, slightly more than that of the arteries in the longitudinal fissure. The basal vein is displaced in the same direction, anteriorly to about the same degree, as the internal cerebral vein. Its posterior part is elongated in a curve, convex medially. Expanding Process of the Insula Case 7z.-Glioma of the left insula. Fig. 63. V-y: Displacement to the right, greatest basally, of the lateral ventricles. The body of the left

14 Fig. 63. Case 72. lateral ventricle is somewhat flattened from below and laterally. Very slight elevation of the anterior horn. Anteriorly, the left temporal horn is slightly flattened and displaced backwards. Arteries: Displacement to the right, greatest fairly far anteriorly, of the arteries in the longitudinal fissure. The arteries of the Sylvian group are slightly deflected laterally; anteriorly, some of them are separated. '34

15 Central veins: The internal cerebral vein is displaced to the right, somewhat more than thc arteries in the longitudinal fissure; anteriorly, it is shifted upwards. Medial displacement of the basal vein; thus in the same direction as that of the internal cerebral vein and to about the same degree. It is also slightly deflected downwards. Its tributaries from the insula are considerably thicker than usually, indicating an increased blood flow from the insula. '35