MARCH, 1976 Pre EMBOLIC OCCLUSION OF THE SUPERIOR AND IN- FERIOR DIVISIONS OF THE MIDDLE CEREBRAL ARTERY WITH ANGIOGRAPHIC-CLINICAL CORRELATION* ABSTRACT: Superior Rolandlc rolandic By L. REED ALTEMUS, M.D., GLENN H. ROBERSON, M.D., C. MILLER FISHER, M.D., and MICHAEL PESSIN, M.D. BOSTON, MASSACHUSETTS Clinicians, in defining cerebral vascular syndromes, recognize embolism to the superior and inferior divisions of the middle cerebral artery in addition to embolism of the individual branches. In the present study 14 examples of arteniographically visualized divisional occlusion are analyzed, and a good correlation is demonstrated between the roentgenologic and clinical findings. T HE branching pattern of the middle clinico-pathologic interpretation of embolic cerebral artery (MCA) is variable and strokes in the MCA territory, neurologists a variety of MCA nomenclatures has been have recognized two main divisions of the suggested. 5 6 8 #{176} As early as 1958, ii the MCA, a superior and an inferior. The con- L. Division Inferior Division FIG. I. Diagram illustrating the classical branching pattern of the superior and inferior divisions. Central sulcus between anterior parietal and rolandic arteries separates areas of motor from sensory functions. * From the Departments of Radiology and Neurology, Harvard Medical School, and Massachusetts General Hospital, Boston, Massachusetts. 576
VOL. is6, No. 3 Embolic Occlusion of Middle Cerebral Artery 577 TABLE I ANGIOGRAPHIC LOCALIZATION OF MIDDLE CEREBRAL OCCLUSIONS. Location S Prior to origin of striate arteries. ;. 2. (A) r division embolus (arrows) cxtending into proximal branches. Large frontal avascular zone results from occlusion. Inferior division including its branches appears normal (arrow). (B) Photographic enlargement of superior division embolus (arrows), bifurcation of both divisions (b) and normal appearing inferior dlvision (large arrow). No. Cases of Approximate Percent Proximal stemt 5 6 Distal stem 27 32 Superior Division 9 10 Inferior Division 6 Combined division (saddle) 3 15 Distal branches 30 Total 84 FIG. 3. (A) Embolus within distal inferior division (arrow). Superior division identified by arrowhead. (B) Photographic enlargement of normal superior division (arrowhead) with embolus in inferior division (arrow). (C) Late arterial phase demonstrating slow antegrade flow within the three major branches of the inferior division: posterior parietal (p), angular (a), and temporal (t).
Altemus, Robenson, Fisher and Pessin 578 MARCH, 1976 4,.-.:: ;,- : v_ :. ;,..,1 :,..)#{149} r : rh c.l!:. : :kt \ t. 4. area indicates extent ofinfarction and corresponds to territory supplied by the inferior * The three reference levels at.5 cm intervals are superimposed on angiogram using inner table ofskull and Reid s baseline as common reference points. Measurements were corrected for magnification difference. responding angiographic definition of divisional MCA occlusion is undertaken in the present study. We define a classic superior division as a major trunk consisting of four ascending branches, the lateral orbitofrontal, prerolandic, rolandic, and anterior panietal; while the inferior division consists of the remainder of the MCA branches, namely, posterior parietal, angular, and temporal arteries (Fig. i). Minor exceptions to this model are commonly definable angiographically; e.g., the orbitofrontal branch may arise from the distal main MCA stem* rather than the proximal superior division, or the anterior temporal may originate from the distal MCA system rather than the proximal inferior division. Thus is cxplained the escape of one or both of these branches in distal MCA occlusion by a large embolus arrested at the point where the MCA bifurcates into its two divisions. Posteriorly, the anterior parietal branch may arise from the inferior division rather S The term stem refers to the section ofsuperficial artery lying between the origin ofthe MCA and the first major branch.4
VOL. i26, No. 3 Embolic Occlusion of Middle Cerebral Artery 579 than the superior. Despite these anatomical variations, a superior division supplying three on four individual branches is present in 90 percent of anatomic specimens. MATERIAL Eighty-four angiographic examples of occlusion of the MCA or its branches were reviewed (Table I) and from this group 14 satisfying our angiographic criteria of division occlusion were selected for special study. In addition the clinical manifestations of the eleven cases with divisional occlusion in the left or dominant hemisphere were analyzed. j::--, 5. TcJ occlusion of superior division. (. Large frontal avascular zone resulting from superior division occlusion. (B) Later arterial phase of (A) showing simultaneous retrograde filling of A) superior division branches (arrows). F i, Retrograde right brachial arteriogram showing avascular parietal-temporal zone resulting from total occlusion of inferior division. Flash filling of opposite hemispheric MCA branch mdicated by arrowhead. (B) Reconstitution of the three major branches of the inferior division by retrograde collateral circulation primarily from the post cerebral artery (PC). RESULTS Division occlusion by an embolus was angiographically defined either by demonstrating a filling defect within the lumen (Fig. 2-4) or by demonstrating abrupt total occlusion of the division with simultaneous retrograde filling of all its major branches by collaterals (Fig. 5; and 6). Intraluminal filling defects representing emboli were visible in four of 14 cases while the remainder showed total occlusion with reconstitution by retrograde flow. Collateral filling of superior division branches was
58o Altemus, Robenson, Fisher and Pessin MARCH, 3976 -.- Anterior Speech (Broca) (Motor) FIG. 7. Functional areas of dominant hemisphere. Motor and sensory areas separated by central sulcus and in turn perfusion territories of superior and inferior divisions. Compare with Figure I. furnished by multiple branches of the ipsilateral anterior cerebral artery, while inferion division branches were reconstituted by multiple branches of the ipsilateral postenor cerebral artery or the penicallosal artery, or both. Callosomarginal arteries in the cingulate sulcus never participated in collateral flow to inferior division territory. Clinical-angiographic correlations were undertaken in the eleven cases involving occlusion in the dominant hemisphere with aphasia. Clinicians have found that embolism to the superior division causes a hemiplegia and motor aphasia due to infarction of the motor cortex and Broca s area respectively, whereas embolism to the infenior division does not cause a hemiplegia nor paralysis since the motor area of the brain is spared, but gives rise to Wernicke s aphasia as a result of infarction of the temporal lobe2 (Fig. 7). It was to examine this clinico-pathologic rule that the eleven cases were analyzed. Six of seven patients with superior di- Posterior Speech (Sensory) Optic Radiations vision occlusion showed severe hemiplegia with motor aphasia while all four patients with inferior division occlusion exhibited sensory receptive aphasia without motor weakness. Three of four inferior division occlusions had a hemianopia. This excellent correlation of the clinical and roentgenological findings during the acute phase of the illness strongly supported the conclusions derived from pathologic studies. In the past, clinical manifestations have been correlated wi th angiographically proved occlusion of individual branches of the MCA.7 The concept ofdivision occlusion, however, has not been clearly formulated. We have found it very useful in increasing the precision of clinico-angiographic correlation. Moreover, appreciation ofthe anatomy ofdivisions assists in understanding the angiographic distribution of embolic fragments and in interpreting the clinical picture in what appear to be partial or incomplete divisional syndromes. Magnification and subtraction techniques should
VOL. 126, No. 3 Embolic Occlusion of Middle Cerebral Artery 8 I be employed for optimal visualization of intraluminal emboli and consideration should be given to visualizing the various routes of collateral circulation, particularly if none is visible by unilateral carotid injection. This is particularly true of inferior division occlusion where collateral vessels may be demonstrated only by opacification of the posterior cerebral artery (Fig. 6). Since the cervical carotid may serve as a source of emboli, it should be carefully studied. L. Reed Altemus, M.D. Department of Radiology Maine Medical Center 22 Bramhall Street Portland, Maine 04102 REFERENCES I. DELONG, W. B. Anatomy of middle cerebral artery: temporal branches. Stroke, 1973, 4, 412-418. 2. FISHER, C. M. Clinical syndromes in cerebral arterial occlusion. In : Pathogenesis and Treatment of Cerebrovascular Disease. Edited by W. S. Fields. Charles C Thomas, Publisher, Springfield, Ill., 1961. 3. FISHER, C. M., MOHR, J. P., and ADAMS, R. D. Cerebrovascular diseases. In : Harrison s Principles of Internal Medicine. Seventh edition. Chapt. 326. McGraw-Hill, New York, 1974, pp. 1747-1749. 4. FISHER, C. M., MOHR, J. P., and ADAMS, R. D. Cerebrovascular diseases. In : Harrison s Principles of Internal Medicine. Sixth edition. Chapt. 357. McGraw-Hill, New York, 1970, pp. 1731. 5. JAIN, K. K. Some observations on anatomy of middle cerebral artery. Canad. 7. Surg., 1964, 7, 134-139. 6. LASCELLES, R. G., and BURROWES, E. H. Occlusion of middle cerebral artery. Brain, 1965, 88, 85-96. 7. RING, A. B. Angiographic recognition of occlusions of isolated branches of middle cerebral artery. AM. J. ROENTGENOL., RAD. THERAPY & NUCLEAR MED., 1973, 89, 39 1-397. 8. STEPHENS, R. B., and STILWELL, D. L. Arteries and Veins of Human Brain. Charles C Thomas, Publisher, Springfield, Ill., I969, pp. 33-70. 9. VANDER EECKEN, H. M. Anastomoses between Leptomeningeal Arteries of Brain. Charles C Thomas, Springfield, Ill., 1959, pp. 8-i6. 10. WADDINGTON, M. M. Lateral cerebral hemisphere and middle cerebral artery. In: Atlas of Cerebral Angiography with Anatomic Correlation. Little, Brown & Co., Inc., Boston, 1974, 2-45. I I. WADDINGTON, M. M., and RING, A. B. Syndromes of occlusions of middle cerebral artery branches. Brain, 1968, 91, 685-696.
This article has been cited by: 1. Daniel K. Kido, Jessica Tan, Steven Munson, Udochukwu E. Oyoyo, J. Paul JacobsonSWI Venographic Anatomy of the Cerebrum 137-150. [CrossRef]