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Hydrocephalus and the congenital anomalies associated with it: Angiographic diagnosis
Hydrocephalus and the Congenital Associated With It : Angiographic By ANTHONY
J. RAIMONDI,
Anomalies Diagnosis
M.D.
T
HE DECISION to perform angiography on the newborn or infant with a large head is predicated upon the need to know: ( 1) the status of the cerebral or cerebellar hemispheres; (2) the presence of an intraventricular space occupying lesion, expansile or static; (3) the existence of hydroccphalus, communicating or obstructive; or (4) less common, but no less important, whether an infectious or vascular process is the cause. The clinical diagnosis of hydrocephalus in the newborn may at times be difficult though, generally speaking, it presents few problems. Similarly, the diagnosis of enlarged ventricles may be made after injecting a variable amount of air into the lateral ventricles. In the past, the diagnosis of communicating hyd:ocephalus was made by injecting dye into a lateral ventricle and then withdrawing fluid from the lumbar subarachnoid space and determining whether it was colored.“,‘-’ A more ambitious request concerning the specific nature and site of obstruction necessitated a complete air exchange with manipulation of the head.” In essence, using small amounts of Pantopaque requires the same manipulation, yet only provides information concerning the site of blockage. These studies are complicated and sometimes dangerous, so are often omitted. Thus, most hydrocephalic infants presently have shunting procedures as soon as the genetic diagnosis of hydrocephalus is made. In 1951, Tolosa reported preliminary angiographic studies on the hydrocephalic infant,” and in 1959 Faure and Gruson described the arteriographic characteristics of such specific tumors as the craniopharyngioma.’ The work of Paillas et al. concerned itself with the diagnosis and localization of vascular anomalies and suspected vascular tumors such as choroid plexus papilloma,” With few exceptions, the reports published on angiography in childhood are concerned with the juvenile and adolescent age groups.’ ‘?I”” The limited knowledge regarding the normal angiogram and its variations diminished the reliability of this procedure in the newborn and infant. However, recent studies have served as a basis for an improved systematic analysis of the angiographic characteristics of hydrocephalus.‘,‘” I6 Hydrocephalus is not a single disease entity, nor is it a syndrome.” The various etiologic factors range from congenital malformation’” through neoplasm to meningitis. From a practical point of view, it is best to consider external hydrocephalus as a collection of fluid over the surface of the brain (in the subdural compartment). Internal hydrocephalus results in an increase in ven-
Supported in part by a grant from nois Department of Mental Health Memorial Hospital, Chicago, 111.
the Psychiatric and by general
Training
ANTHONY J. RAIMONDI, M. D.: Professor of Surgery Chairman of Neurosurgery, Children’s Memorial
versity;
SEMINARSINROENTCENOLOGY,VOL.~,NO.~
research
and Research Fund funds from the
(Neurosurgery),
Hospital, Chicago,
(JANUARY), 1971
of the IlliChtldren’s
Northwestern Ill. 60614.
Uni-
111
ANTHONY
Fig. L-External hydrocephalus, A. Arterial phase showing bilateral subdural fluid and a filling defect on the left. B. AP venous phase. The cortical veins are thin and stretched. C. Lateral venogram. The bridging veins are elongated with loss of norrnak angulation.
J, RAIMONDI
HYDROCEPHALUSANDTHECONGENITALANOMALIES
113
tricular size, intraventricular pressure, and volume of intraventricular cerebrospinal fluid. It may be subdivided into communicating, obstructive, and constrictive varieties. In communicating hydrocephalus, there is free flow of fluid from the lateral ventricles, through the midline third and fourth ventricles, and out into the basal cisterns. These latter are invariably enlarged. Obstructiw hydrocephalus, as the name implies, consists of a distension of the ventricular system upstream from the point of obstruction, which may be located at a foramen of Monro, at the aqueduct of Sylvius, or at the foramina of Luschka and Magendie. It is essential to know the degree of vascularization of the cortex and brain stem since it is this, and not the mantle thickness, that determines the amenability of the hydrocephalic process to surgery. Laurence and Coates stressed that there is no meaningful correlation between thickness of the cerebral mantle and subsequent intellectual development.” In studying the angiographic characteristics of hydrocephalus in the newborn, we should (1) make a diagnosis of hydrocephalus; (2) determine whether th? hydrocephalus is internal or external; (3) if internal, determine whether it is communicating or obstructive; (4) if obstructive, determine the nature and exact point of occlusion; and (5) evaluate the status of cortical and brain stem vascularity as an index of the reversibility of the hydrocephalic process. We will explain our angiographic criteria for arriving at a diagnosis of the The clinical material for this specific type of hydrocephalus in the newborn.“’ report consists of 450 hydrocephalic newborns and infants studied angiographically during the years 1963 to 1970. EXTERNALHYDROCEPHALUS
In the anteroposterior and axial projections, the arterial phase demonstrates the convex outline of the brain and the large space filling defect located over all portions of the cerebral cortex. The single most characteristic roentgen observation is the collection of fluid in the subdural space along the surface of the falx cerebri bilaterally (Fig, 1A). In the lateral projection, the early and midarterial phases reveal a space filling defect over the entire convexity of the brain, again with evidence of fluid in the subdural space. This projection also discloses anterior displacement of the anterior cerebral artery, indicative of enlargement of the lateral ventricle; and occasional elevation of the middle cerebral artery in the sylvian fissure, indicative of an enlarged temporal horn. In the AP projection during the venous phase, the cortical veins course over the surface of the hemisphere and bridge the subdural fluid collection to reach the superior longitudinal sinus (Fig. 1B ). These veins are long, thin, and stretched. Depression and flattening of the venous angle are evidence of an enlarged body of the lateral ventricle. In the lateral projection, the filling of the cortical veins is impressive (Fig. 1C ) . It is possible to see an entire lobe draining into a complex of veins and to identify readily the main vein that receives these tributaries. These large bridging veins are stretched as they pass through the subdural fluid. They lose
114
ANTHONYJ.RAIMONDI
their normal angulation and enter the superior sagittal sinus at a right angle. These bridging veins appear to suspend the cerebral hemispheres from the superior sagittal sinus, hence our descriptive term ‘hanging veins,” INTERNALHYDROCEPHALUS
In all types of internal hydrocephalus, the arteries and veins are stretched, deformed, or displaced. In addition, the superior and lateral sinuses may also be displaced. The distinction between the types of internal hydrocephalus, communicating and obstructive, is based on the relative changes between arteries, veins, and sinuses, thus permitting extrapolation of lateral and/or midline ventricular enlargement . . . . and identification of foraminal (Monro, Luschka, or Magendie) occlusion or aqueduct stenosis. A normal complement of anterior, middle, and posterior cerebral arteries and branches, irrespective of the size of the ventricles or the thickness of the cerebral mantle, in a newborn or an infant under three months of age, indicates that the hydrocephalic process is still amenable to a shunting procedure and that the child’s intellectual potential is equal to that of his peer group.” Absence of one or more of the major branches of either the internal carotid or vertebrobasilar system in a child with hydrocephalus indicates porencephaly, lobar aplasia, or hydranencephaly.
Communicating
Hydroceplzalus
The specific changes seen in the arterial and venous anatomy of the newborn with communicating hydrocephalus permit its diagnosis and an estimation of the degree of enlargement in the aqueduct and each of the four ventricles. These observations may serve for comparison when localizing the site of occlusion in obstructive hydrocephalus. In the AP arteriogram, the anterior cerebral arteries in the midline are “strung” tautly between the anterior communicating artery below and the genu of the corpus callosum above. The middle cerebral arteries are displaced laterally and inferiorly, with the resultant increased space between the anterior and middle cerebral arteries reflecting enlargement of the corresponding lateral ventricle ( Fig. 2A). Inferolateral displacement of the lenticulostriate arteries indicates the direction in which the basal ganglia and thalami are shifted. When the temporal horns are maximally enlarged, the middle cerebral artery angulates superolaterally as it passes through the sylvian fissure, wedged between distending frontal and temporal horns. The wide circular sweep of the posterior cerebral arteries around the brain stem outline an enlarged aqueduct. The obtuse angle created by the posteroinferior temporal and internal occipital branches of the posterior cerebral artery results from dilatation of the trigone of the lateral ventricle. In the lateral projection, the anterior cerebral artery is displaced anteroinferiorly and is bowed over the genu and body of the corpus callosum (Fig. 2B). The normal posteroinferior sweep of this artery down to and around the splenium of the corpus callosum is lost. These changes in the anterior cerebral artery are caused by enlargement of the third and lateral ventricles. The
HYDROCEPHALUS
AND THE CONGENITAL
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Fig. 2.-Internal communicating hydrocephalus. A. AP arterial phase. Increased distance between the anterior and middle cerebral arteries indicates enlarged lateral ventricles. 8. Lateral arteriogram. Anteroinferior displacement of the anterior cerebral artery by dilated third and lateral ventricles. C. Venous phase, lateral view. The deep venous structures are altered by the enlarged aqueduct and third and fourth ventricles.
116
ANTHONY
J. RAIMONDI
Fig. 3.-Occlusion of one foramen of Monro, obstructive hydrocephalus. A. Early arterial phase. Dilatation of the right lateral ventricle is shown by the increased distance between the anterior and middle cerebral arteries and the contralateral shift of the anterior cerebral. B. Bowing of the anterior cerebral artery by the enlarged body of the lateral ventricle. The middle cerebral artery is vertically directed by the dilated temporal horn. Displacement of the superior sagittal sinus, inferior longitudinal sinus, and the deep cerebral veins to the left was evident in the AP venous phase.
ventricular distension is also responsible for the portion of the pericallosal artery. If the body proportionately larger than the temporal horn, be displaced slightly inferiorly and posteriorly. is disproportionately larger than the body, the elevated.
upward course of the terminal of the lateral ventricle is disthe middle cerebral artery will However, if the temporal horn middle cerebral artery will be
HYJMOCEPHALUS
AND THE CONGENITAL
ANOMALIES
117
The posterior communicating and posterior cerebral arteries follow a superior and posterior rectilinear course around the brain stem and over the surface of the tentorium, flattened between expanding supratentorial and infratentorial compartments. The basilar artery is displaced anteriorly until it comes to rest on the clivus. The superior cerebellar arteries course posteriorly and superiorly and then directly downward and backward. The posteroinferior and anteroinferior cerebellar arteries are displaced posteriorly and inferiorly as they course over the inferior surface of the cerebellar vermis and hemispheres. These two vessels are separated from the inner table of the squamous portion of the occipital bone by a space filling defect, the enlarged cisterna magna. All the changes in the arterial structures of the posterior fossa are indicative of both an enlarged fourth ventricle and cisterna magna. In the axial projection the enlarging third ventricle widens the circle of Willis giving it an almost circular appearance. The venous phase in AP projection permits a diagnosis of a dilated lateral ventricle. Inferior displacement of the thalamostriate-terminal vein complex occurs. The veins of Rosenthal are shifted laterally by the enlarged aqueduct and join one another at the vein of Galen to form the apex of an isosceles triangle. It is in the lateral projection that the deep venous system is most characteristic (Fig. 2C). There is an increase in the posterosuperiorly directed convexity of the internal cerebral vein, a result of distension of the roof of the third ventricle. The vein of Rosenthal courses superiorly and posteriorly as it goes to join the internal cerebral vein and then the vein of Galen. The plane created by the extension of the vein of Rosenthal into the vein of Galen forms one side of the apex of an isosceles triangle, the other side of which is formed by the straight sinus; the base is the lateral sinus. The straight sinus is directed inferiorly and posteriorly in its course from the point at which the vein of Galen enters it to the torcular Herophili. These changes in the deep venous structures and the straight and lateral sinuses indicate an increase in the size of the aqueduct and the third and fourth ventricles. Obstructive
Hydrocephalus
Anatomically, obstructions may occur at a foramen of Monro, the aqueduct of Sylvius, or the foramina of Luschka and Magendie. Congenital occlusion of one foramen of Monro is extremely rare. Only two cases other than the one reported here have been published, and there is some cause to think that both of these may have been infectious in origin.” The occlusion results in enormous distension of one lateral ventricle, so that the angiographic picture is one of asymmetrical hydrocephalus (Fig. 3). Aqueduct stenosis. Occlusion, stenosis, or forking of the aqueduct represent the most common causes of obstructive hydrocephalus. In point of fact, approximately 55 per cent of all congenital hydrocephalus is caused by diminished %ow through the aqueduct of Sylvius.” In addition to the general angiographic characteristics of hydrocephalus, there are specific alterations in the course and
118
ANTHONY
J. RAIMONDI
Fig. I.-Aqueduct stenosis, obstructive hydrocephalus. A. Arterial phase, axial view. Enlarged diameter of circle of Willis. B. AP projection. The posterior cerebral arteries are smoothly curvilinear as they course around the small brain stem. The anterior and middle cerebral artery configuration is typical of hydrocephalus. C. Lateral arteriogram. Anterosuperior stretching of the posterior cerebral and posterior communicating arteries.The posterior cerebralinternal occipital complex is almost horizontal. D. Venous phase. The expanded supratentorial ventricles displace the internal cerebral vein inferiorly and flatten the vein of Galen.
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AND
THE CONGENITAL
ANOMALIES
119
form of the major arterial and venous structures which permit the diagnosis of aqueduct obstruction ( Fig. 4). In the axial projection (Fig. 4A), the arteriogram reveals an enlarged diameter of the circle of Willis as seen in communicating hydrocephalus. The posterior cerebral arteries in aqueduct stenosis adhere to the midbrain in their sweep first laterally and then posteriorly to the point at which they extend directly into the internal occipital artery. In the AI? view (Fig. 4B), the posterior cerebral-internal occipital complex passes posteriorly and medially in a linear direction without any sharp angulation, implying a small brain stem. This finding, combined with the enlarged circle of Willis denoting a dilated third ventricle, localizes the obstruction to the aqueduct of Sylvius. Otherwise the AP arteriogram is indistinguishable from that of communicating hydrocephalus. The deep venous structures differ from those in communicating hydrocephalus only in that the veins of Rosenthal are medially displaced and follow an almost parallel course as they go to the vein of Galen. This indicates constriction of the brain stem by expansion of the lateral ventricles without expansion of the aqueduct. In the lateral projection (Fig, 4C), the arteriogram differs from communicating hydrocephalus only in two respects. The perforating branches of the posterior cerebral and posterior communicating arteries are directed superiorly and anteriorly and are stretched. In addition, the posterior cerebral-internal occipital complex follows an almost horizontal course from the origin of the posterior cerebral artery to the point at which the internal occipital artery bifurcates into the calcarine and cuneate branches. The lateral venous phase is characteristic and provides the most reliable diagnostic information ( Fig. 4D ) . The internal cerebral vein is displaced anteriorly and inferiorly, and the vein of Galen is lengthened and flattened. This results in an almost linear appearance of the internal cerebral vein and what appears to be direct continuation with the vein of Galen. This stretched and horizontal course of the two veins results from the anterior inferior displacement of the thalamus and basal ganglia by the expanded supratentorial ventricular system uncumbered by expansion in the infratentorial compartment. The course of the straight sinus is almost vertical. Inferior displacement of the lateral sinuses indicates a diminution in overall size of the posterior fossa. Atresia of the foramina of Luschka and Magendie (the Dandy-Walker cyst) is a most characteristic form of obstructive hydrocephalus in that it presents clinically as communicating hydrocephalus, but subsequently develops into a picture of obstructive hydrocephalus and posterior fossa space occupying lesion.15 The reason for this rests in the fact that the fourth ventricle is transformed into an enormous cyst which compresses the brain stem and displaces the cerebellar hemispheres superiorly and laterally, with resultant kinking of the aqueduct and secondary distension of the supratentorial ventricular system.” The angiographic diagnosis of the Dandy-Walker cyst depends on adequate visualization of the vascular structures in the posterior fossa. The arteriographic and venographic characteristics of the supratentorial compartment are diag-
120
ANTHONY
J. RAIMONDI
Fig. 5.-Atresia of the foramina of Luschka and Magendie (Dandy-Walker cyst). A. Arterial phase.
Large, spaceoccupying defect in posterior fossa displaces the arteries, occipital lobe, and cerebellar hemispheresanteriorly. B. Venous phase. Note displacement of the venous sinusesin the greatly enlarged posterior fossa.
nostic of hydrocephalus. However, when the vascular structures of the posterior fossa are demonstrated, it becomes possible to state that the fourth ventricle is maximally dilated. The AP arterial phase reveals that the posterior cerebral arteries pass directly laterally and form a right angle as they turn superiorly. These arteries never approach the midline, but rather pass directly upward to their termination. This failure of the posterior cerebral arteries to return to the midline as they course over the medial surface of the occipital lobe is probably the result of the superior displacement of the tentorium secondary to the cystic transformation of the fourth ventricle. The lateral arteriogram shows anterior displacement of the basilar artery so
HYDROCEPHALUS
AND
THE
CONGENPIAL
ANOMALIES
121
that it abuts upon the clivus (Fig, 5A). The posterior cerebral arteries follow a markedly superior and slightly posterior course since the occipital lobe is displaced superiorly and slightly anteriorly. The posteroinferior and anteroinferior cerebellar arteries outline the inferior surface of each cerebellar hemisphere and reveal it to maintain its normal convexity, though it is displaced anteriorly and superiorly. Similarly, the superior cerebellar arteries, which outline the superior surface of the vermis and cerebellar hemispheres, permit visualization of the convex superior surface of the cerebellar hemisphere displaced forward and upward through the tentorial opening. It is possible to see a very large space filling defect beneath the inferior surface of the cerebellar hemispheres because of the lack of vascular structures within it. This, in essence, is the cystic transformation of the fourth ventricle. AP projection of the venous phases reveals that the internal cerebral veins do not occupy their normal paramedian position, but that they are laterally displaced and follow a medial and superior course as they go to join the vein of Galen. This latter structure is impossible to identify in the AP projection, The lateral sinuses are elevated superiorly and laterally, the result of the expansile cystic mass within the posterior fossa. The torcular Herophili is located almost at the vertex of the skull. Lateral venograms exhibit anterior and superior displacement and elongation of the internal cerebral vein (Fig. 5B). The posterosuperior course of the vein of Galen as it passes to meet the superiorly displaced straight sinus is apparent, The latter structure is almost horizontal as it enters the elevated torcular Herophili. The lateral sinuses, which take their origin from the torcular, pass forward and downward in a rectilinear course to enter the sigmoid sinuses. These alterations in the sinus structures indicate the enormous increase in volume of the posterior fossa. Constrictive
Hydrocephalus
The angiographic criteria by which constrictive hydrocephalus is diagnosed consist of kinking of the vertebral arteries at the occipitocervical junction, angulation of the vertebral and the basilar arteries over the pontomedullary junction, and dislocation of the posterio inferior carotid artery into the cervical canal. The lateral projection is most valuable in the diagnosis of this type of hydrocephalus. Platybasiu and basilar impression. Theoretically, it is simple to distinguish between flattening of the base of the skull (platybasia) and a deformity of the squamous and basilar portions of the occipital bone (basilar impression), characterized by an indentation of the foramen magnum. At a clinical level, however, this is quite another matter since the symptoms caused by either basilar impression or platybasia are those of cervical cord, hind cranial nerve, and cerebellar dysfunction. In some patients, the deformity may be so severe as to produce a constrictive hydrocephalus. Consequently, the newborn with either of these anomalies may suffer repeated episodes of aspiration pneumonia, regurgitation through the nose, vocal cord paralysis, spontaneous nystagmus, irregular respiratory rate, and, on occasion, progressive increase in head size
ANTHONYJ.RAIMONDI
Fig. 6.-Agenesis of corpus callosum. A. Deformed third ventricle on pneu-
mography. B and C. Displacement the anterior cerebral artery.
of
with a clinical diagnosis of hydrocephalus. Laminagraphic studies may reveal the craniovertebral anomaly. Pancraniostenosis. The pancraniostenosis associated with Hurler’s disease and craniovertebral anomalies may cause a constrictive process in the basal cisterns at the level of the foramen magnum. This results in impairment of circulation of the CSF through the foramina of Luschka and Magendie and the basal cisterns. The resultant hydrocephalus is of the constrictive variety. OTHER CONGENITAL
ANOMALIES
COMMONLY
AS.WCIATED
WITH HYDROCEPHALUS
Agenesis of Corpus Callosum Of relatively common occurrence is agenesis of the corpus callosum. Though this may exist in an otherwise normal patient, it is commonly associated with the Dandy-Walker cyst, the Arnold-Chiari malformation, communicating hydrocephalus, craniovertebral anomalies, and other cerebral dysplasias. The deformity and elevation of the third ventricle which result from agenesis of the body of the corpus callosum cause characteristic displacement and elevation of the pericallosal artery (Fig. 6).
HYDROCEPHALUS
AND
THE CONGENITAL
ANOMALIES
123
Hydranencephaly The first definitive publication of hydranencephaly was that of Cruveilheir in 1833. Morphologic changes in this congenital anomaly are characterized by aplasia of the frontal lobes, parietal lobes, and the dorsolateral surface of the and medial surfaces of the temporal and temporal lobes. The inferior occipital lobes are preserved. The brain stem and cerebellum are generally intact. The result is a congenital malformation characterized by aplasia of that portion of the brain supplied by the anterior and middle cerebral arteries. It is precisely this discrete distribution which has led many authors to conclude that hydranencephaly is the result of a primary intrauterine vascular dysplasia of the internal carotid artery just distal to the origin of the anterior choroidal. Well over 90 per cent of the children born with this congenital malformation have an associated occlusion of the aqueduct which results in an accumulation
Fig. 7.-Hydranencephaly. A. Dysplasia of the
internal carotid arteries distal to the origin of the anterior choroidals. B. Shunting of contrast medium from the arterial directly into the deep venous system with premature filling of the straight and lateral sinuses.The brain stem is stained.
124
ANTHONY
J. RAIMONDI
of cerebral spinal fluid within the supratentorial compartment. Consequently, these children appear to have severe hydrocephalus. Careful neuroradiologic evaluation reveals that the primary problem is not hydrocephalus. In point of fact, hydranencephaly has been repeatedly confused with severe hydrocephalus. The air study reveals an almost total absence of cerebral mantle in the entire supratentorial compartment except for portions of the temporal and occipital lobes. Cerebral angiography (Fig. 7) reveals normal vertebral basilar, posterior cerebral, and anterior choroidal artery systems. However, the internal carotid artery is attenuated immediately superior to the anterior choroidal artery. On occasion, there may be a hypoplastic anterior cerebral artery or a truncated cerebral artery. The terminal branches of the middle and anterior cerebral arteries are absent. The stained basal ganglia, thalami, and brain stem often stand out in stark contrast to the absen cerebral hemispheres. There is early filling of the straight and lateral sinuses. Porencephaly Technically, porencephaly signifies a cystic area within the parenchyma of either cerebral hemisphere. The cyst is generally in contact with the subarachnoid space over the surface of the brain and with the ependyma of the ventricular lining. However, this does not always obtain. Many porencephalic cysts communicate with the ventricular system but not with the subarachnoid space. Occasionally the reverse is true. Therefore, one may not be sure whether a porencephalic cyst is present or absent on the basis of air studies alone. The angiographic picture of a porencephalic cyst is indistinguishable from that of any other nonvascular space occupying lesion of the cerebral hemispheres. However, since porencephaly is often associated with hydrocephalus of either communicating or obstructive variety, one may suspect the presence of a porencephalic cyst in a hydrocephalic child who has a nonvascular space occupying lesion in the cerebrum.
REFERENCES 1. Achslogh, J., and Saintes, M.-J.: L’artkriographie normale et pathologique du nourisson et du jeune enfant. Acta Neural. belg. 61: 162, 1961. 2. Carrea, R.: Angiografia cerebral en el niiio. Communication preliminar. Ann. Inst. Med. Exp. Roffo 269, 1950. 3. Dandy, W. E.: The diagnosis and treatment of hydrocephalus due to occlusions of the foramina of Magendie and Luschka. Surg. Gynec. Obstet. 32:112, 1921. 4. Dandy, W. E., and Blackfan, K. D.: An experimental and clinical study of internal hydrocephalus. JAMA 61:2216, 1913.
5. DeLange, S. A.: Surgical treatment of progressive hydrocephahrs. Amsterdam, North-Holland Publishing Co., 1966, p. 134. 6. Dott, N. M.: A case of unilateral hydrcF cephahrs in an infant. Operation-cure. Brain 50:548,1927. 7. Faurk, C., and Gruson, B.: L’exploration radiologique des craniopharyngiomes de I’enfant (a propos de 17 observations). Ann. Radiol. 2: 197, 1959. 8. Laurence, K. M.: Some applications of the urinary phenolsulphonphthalein excretion test in hydrocephahrs and related conditions. Brain 82:551, 1959.
HPDROCEPKlLUS
AND
THE CONGENITAL
ANOMALIES
9. Laurence, K. M., and Coates, S.: Further thoughts on the natural history of hydrocephalus. Develop. Med. Child. Neurol. 4:263,1962. 10. Matson, D. D.: Prenatal obstruction of the fourth ventricle. Amer. J. Roentgen. 76: 499,1956. 11. Paillas, J.-E., Bonnal, J., Berard-Badier, and Serratrice, G.: Les angiomes arterioveineux du cerveau chez l’enfant. Presse Med. 66:525,1958. 12. Picaza, J. A.: Cerebral angiography in children: an anatomoclinical evaluation. J. Neurosurg. 9:235, 1952. 13. Raimondi, A. J.: The neuroradiologic evaluation of craniocerebral injury in the newborn and infant. Minerva Pediat. 21.: 1251,1969. 14. Raimondi, A. J., Grossman, H. J., and Warren, S. A.: Intellectual levels of children with repeated shunt surgery for hydrocephalus. Presented to the Amer. Acad. Ped., Oct. 1968. 15. Raimondi, A. J., Samuelson, C. H., Yarzagaray, L., and Norton, Ft. F.: Angiographic diagnosis of communicating hydro-
125
cephalus in the newborn. J. Neurosurg. 31: 550,1969. 16. Raimondi, A. J., and White, H.: Cerebral angiography in the newborn and infant: general principles. Ann. Radiol. 10: 147,1967. 17. Russell, D. 8: Observations on the Pathology of Hydrocephalus. London, Her Majesty’s Stationery Office, 1949, p. 152, 18. Taveras, J. M.: Neuroradiology in children. In Clinical Neuroradiology. New York, McGraw-Hill, 1966, pp. 359-399. 19. Taveras, J. M., and Poser, C. M.: Roentgenologic aspects of cerebral angiography in children. Amer. J. Roentgen. 82: 371,1959. 20. Tinel, J., de Martel, T., and Guillaume, J.: Hydrocephalie unilaterale. Intervention, Gukrison, Rev. Neurol. 1:415, 1932. 21. Tolosa, E.: L’exploration arteriographique dans l’hydrocephalie infantile. Semaine Hop. Paris 27:2401, 1951. 22. Walker, A. E.: A case of congenital artesia of the foramina of Luschka and Magendie: surgical cure. J. Neuropath. Exp. Neurol. 3:368, 1944.
4
J. RAIMONDI,
Anomalies Diagnosis
M.D.
T
HE DECISION to perform angiography on the newborn or infant with a large head is predicated upon the need to know: ( 1) the status of the cerebral or cerebellar hemispheres; (2) the presence of an intraventricular space occupying lesion, expansile or static; (3) the existence of hydroccphalus, communicating or obstructive; or (4) less common, but no less important, whether an infectious or vascular process is the cause. The clinical diagnosis of hydrocephalus in the newborn may at times be difficult though, generally speaking, it presents few problems. Similarly, the diagnosis of enlarged ventricles may be made after injecting a variable amount of air into the lateral ventricles. In the past, the diagnosis of communicating hyd:ocephalus was made by injecting dye into a lateral ventricle and then withdrawing fluid from the lumbar subarachnoid space and determining whether it was colored.“,‘-’ A more ambitious request concerning the specific nature and site of obstruction necessitated a complete air exchange with manipulation of the head.” In essence, using small amounts of Pantopaque requires the same manipulation, yet only provides information concerning the site of blockage. These studies are complicated and sometimes dangerous, so are often omitted. Thus, most hydrocephalic infants presently have shunting procedures as soon as the genetic diagnosis of hydrocephalus is made. In 1951, Tolosa reported preliminary angiographic studies on the hydrocephalic infant,” and in 1959 Faure and Gruson described the arteriographic characteristics of such specific tumors as the craniopharyngioma.’ The work of Paillas et al. concerned itself with the diagnosis and localization of vascular anomalies and suspected vascular tumors such as choroid plexus papilloma,” With few exceptions, the reports published on angiography in childhood are concerned with the juvenile and adolescent age groups.’ ‘?I”” The limited knowledge regarding the normal angiogram and its variations diminished the reliability of this procedure in the newborn and infant. However, recent studies have served as a basis for an improved systematic analysis of the angiographic characteristics of hydrocephalus.‘,‘” I6 Hydrocephalus is not a single disease entity, nor is it a syndrome.” The various etiologic factors range from congenital malformation’” through neoplasm to meningitis. From a practical point of view, it is best to consider external hydrocephalus as a collection of fluid over the surface of the brain (in the subdural compartment). Internal hydrocephalus results in an increase in ven-
Supported in part by a grant from nois Department of Mental Health Memorial Hospital, Chicago, 111.
the Psychiatric and by general
Training
ANTHONY J. RAIMONDI, M. D.: Professor of Surgery Chairman of Neurosurgery, Children’s Memorial
versity;
SEMINARSINROENTCENOLOGY,VOL.~,NO.~
research
and Research Fund funds from the
(Neurosurgery),
Hospital, Chicago,
(JANUARY), 1971
of the IlliChtldren’s
Northwestern Ill. 60614.
Uni-
111
ANTHONY
Fig. L-External hydrocephalus, A. Arterial phase showing bilateral subdural fluid and a filling defect on the left. B. AP venous phase. The cortical veins are thin and stretched. C. Lateral venogram. The bridging veins are elongated with loss of norrnak angulation.
J, RAIMONDI
HYDROCEPHALUSANDTHECONGENITALANOMALIES
113
tricular size, intraventricular pressure, and volume of intraventricular cerebrospinal fluid. It may be subdivided into communicating, obstructive, and constrictive varieties. In communicating hydrocephalus, there is free flow of fluid from the lateral ventricles, through the midline third and fourth ventricles, and out into the basal cisterns. These latter are invariably enlarged. Obstructiw hydrocephalus, as the name implies, consists of a distension of the ventricular system upstream from the point of obstruction, which may be located at a foramen of Monro, at the aqueduct of Sylvius, or at the foramina of Luschka and Magendie. It is essential to know the degree of vascularization of the cortex and brain stem since it is this, and not the mantle thickness, that determines the amenability of the hydrocephalic process to surgery. Laurence and Coates stressed that there is no meaningful correlation between thickness of the cerebral mantle and subsequent intellectual development.” In studying the angiographic characteristics of hydrocephalus in the newborn, we should (1) make a diagnosis of hydrocephalus; (2) determine whether th? hydrocephalus is internal or external; (3) if internal, determine whether it is communicating or obstructive; (4) if obstructive, determine the nature and exact point of occlusion; and (5) evaluate the status of cortical and brain stem vascularity as an index of the reversibility of the hydrocephalic process. We will explain our angiographic criteria for arriving at a diagnosis of the The clinical material for this specific type of hydrocephalus in the newborn.“’ report consists of 450 hydrocephalic newborns and infants studied angiographically during the years 1963 to 1970. EXTERNALHYDROCEPHALUS
In the anteroposterior and axial projections, the arterial phase demonstrates the convex outline of the brain and the large space filling defect located over all portions of the cerebral cortex. The single most characteristic roentgen observation is the collection of fluid in the subdural space along the surface of the falx cerebri bilaterally (Fig, 1A). In the lateral projection, the early and midarterial phases reveal a space filling defect over the entire convexity of the brain, again with evidence of fluid in the subdural space. This projection also discloses anterior displacement of the anterior cerebral artery, indicative of enlargement of the lateral ventricle; and occasional elevation of the middle cerebral artery in the sylvian fissure, indicative of an enlarged temporal horn. In the AP projection during the venous phase, the cortical veins course over the surface of the hemisphere and bridge the subdural fluid collection to reach the superior longitudinal sinus (Fig. 1B ). These veins are long, thin, and stretched. Depression and flattening of the venous angle are evidence of an enlarged body of the lateral ventricle. In the lateral projection, the filling of the cortical veins is impressive (Fig. 1C ) . It is possible to see an entire lobe draining into a complex of veins and to identify readily the main vein that receives these tributaries. These large bridging veins are stretched as they pass through the subdural fluid. They lose
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ANTHONYJ.RAIMONDI
their normal angulation and enter the superior sagittal sinus at a right angle. These bridging veins appear to suspend the cerebral hemispheres from the superior sagittal sinus, hence our descriptive term ‘hanging veins,” INTERNALHYDROCEPHALUS
In all types of internal hydrocephalus, the arteries and veins are stretched, deformed, or displaced. In addition, the superior and lateral sinuses may also be displaced. The distinction between the types of internal hydrocephalus, communicating and obstructive, is based on the relative changes between arteries, veins, and sinuses, thus permitting extrapolation of lateral and/or midline ventricular enlargement . . . . and identification of foraminal (Monro, Luschka, or Magendie) occlusion or aqueduct stenosis. A normal complement of anterior, middle, and posterior cerebral arteries and branches, irrespective of the size of the ventricles or the thickness of the cerebral mantle, in a newborn or an infant under three months of age, indicates that the hydrocephalic process is still amenable to a shunting procedure and that the child’s intellectual potential is equal to that of his peer group.” Absence of one or more of the major branches of either the internal carotid or vertebrobasilar system in a child with hydrocephalus indicates porencephaly, lobar aplasia, or hydranencephaly.
Communicating
Hydroceplzalus
The specific changes seen in the arterial and venous anatomy of the newborn with communicating hydrocephalus permit its diagnosis and an estimation of the degree of enlargement in the aqueduct and each of the four ventricles. These observations may serve for comparison when localizing the site of occlusion in obstructive hydrocephalus. In the AP arteriogram, the anterior cerebral arteries in the midline are “strung” tautly between the anterior communicating artery below and the genu of the corpus callosum above. The middle cerebral arteries are displaced laterally and inferiorly, with the resultant increased space between the anterior and middle cerebral arteries reflecting enlargement of the corresponding lateral ventricle ( Fig. 2A). Inferolateral displacement of the lenticulostriate arteries indicates the direction in which the basal ganglia and thalami are shifted. When the temporal horns are maximally enlarged, the middle cerebral artery angulates superolaterally as it passes through the sylvian fissure, wedged between distending frontal and temporal horns. The wide circular sweep of the posterior cerebral arteries around the brain stem outline an enlarged aqueduct. The obtuse angle created by the posteroinferior temporal and internal occipital branches of the posterior cerebral artery results from dilatation of the trigone of the lateral ventricle. In the lateral projection, the anterior cerebral artery is displaced anteroinferiorly and is bowed over the genu and body of the corpus callosum (Fig. 2B). The normal posteroinferior sweep of this artery down to and around the splenium of the corpus callosum is lost. These changes in the anterior cerebral artery are caused by enlargement of the third and lateral ventricles. The
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Fig. 2.-Internal communicating hydrocephalus. A. AP arterial phase. Increased distance between the anterior and middle cerebral arteries indicates enlarged lateral ventricles. 8. Lateral arteriogram. Anteroinferior displacement of the anterior cerebral artery by dilated third and lateral ventricles. C. Venous phase, lateral view. The deep venous structures are altered by the enlarged aqueduct and third and fourth ventricles.
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Fig. 3.-Occlusion of one foramen of Monro, obstructive hydrocephalus. A. Early arterial phase. Dilatation of the right lateral ventricle is shown by the increased distance between the anterior and middle cerebral arteries and the contralateral shift of the anterior cerebral. B. Bowing of the anterior cerebral artery by the enlarged body of the lateral ventricle. The middle cerebral artery is vertically directed by the dilated temporal horn. Displacement of the superior sagittal sinus, inferior longitudinal sinus, and the deep cerebral veins to the left was evident in the AP venous phase.
ventricular distension is also responsible for the portion of the pericallosal artery. If the body proportionately larger than the temporal horn, be displaced slightly inferiorly and posteriorly. is disproportionately larger than the body, the elevated.
upward course of the terminal of the lateral ventricle is disthe middle cerebral artery will However, if the temporal horn middle cerebral artery will be
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The posterior communicating and posterior cerebral arteries follow a superior and posterior rectilinear course around the brain stem and over the surface of the tentorium, flattened between expanding supratentorial and infratentorial compartments. The basilar artery is displaced anteriorly until it comes to rest on the clivus. The superior cerebellar arteries course posteriorly and superiorly and then directly downward and backward. The posteroinferior and anteroinferior cerebellar arteries are displaced posteriorly and inferiorly as they course over the inferior surface of the cerebellar vermis and hemispheres. These two vessels are separated from the inner table of the squamous portion of the occipital bone by a space filling defect, the enlarged cisterna magna. All the changes in the arterial structures of the posterior fossa are indicative of both an enlarged fourth ventricle and cisterna magna. In the axial projection the enlarging third ventricle widens the circle of Willis giving it an almost circular appearance. The venous phase in AP projection permits a diagnosis of a dilated lateral ventricle. Inferior displacement of the thalamostriate-terminal vein complex occurs. The veins of Rosenthal are shifted laterally by the enlarged aqueduct and join one another at the vein of Galen to form the apex of an isosceles triangle. It is in the lateral projection that the deep venous system is most characteristic (Fig. 2C). There is an increase in the posterosuperiorly directed convexity of the internal cerebral vein, a result of distension of the roof of the third ventricle. The vein of Rosenthal courses superiorly and posteriorly as it goes to join the internal cerebral vein and then the vein of Galen. The plane created by the extension of the vein of Rosenthal into the vein of Galen forms one side of the apex of an isosceles triangle, the other side of which is formed by the straight sinus; the base is the lateral sinus. The straight sinus is directed inferiorly and posteriorly in its course from the point at which the vein of Galen enters it to the torcular Herophili. These changes in the deep venous structures and the straight and lateral sinuses indicate an increase in the size of the aqueduct and the third and fourth ventricles. Obstructive
Hydrocephalus
Anatomically, obstructions may occur at a foramen of Monro, the aqueduct of Sylvius, or the foramina of Luschka and Magendie. Congenital occlusion of one foramen of Monro is extremely rare. Only two cases other than the one reported here have been published, and there is some cause to think that both of these may have been infectious in origin.” The occlusion results in enormous distension of one lateral ventricle, so that the angiographic picture is one of asymmetrical hydrocephalus (Fig. 3). Aqueduct stenosis. Occlusion, stenosis, or forking of the aqueduct represent the most common causes of obstructive hydrocephalus. In point of fact, approximately 55 per cent of all congenital hydrocephalus is caused by diminished %ow through the aqueduct of Sylvius.” In addition to the general angiographic characteristics of hydrocephalus, there are specific alterations in the course and
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ANTHONY
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Fig. I.-Aqueduct stenosis, obstructive hydrocephalus. A. Arterial phase, axial view. Enlarged diameter of circle of Willis. B. AP projection. The posterior cerebral arteries are smoothly curvilinear as they course around the small brain stem. The anterior and middle cerebral artery configuration is typical of hydrocephalus. C. Lateral arteriogram. Anterosuperior stretching of the posterior cerebral and posterior communicating arteries.The posterior cerebralinternal occipital complex is almost horizontal. D. Venous phase. The expanded supratentorial ventricles displace the internal cerebral vein inferiorly and flatten the vein of Galen.
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form of the major arterial and venous structures which permit the diagnosis of aqueduct obstruction ( Fig. 4). In the axial projection (Fig. 4A), the arteriogram reveals an enlarged diameter of the circle of Willis as seen in communicating hydrocephalus. The posterior cerebral arteries in aqueduct stenosis adhere to the midbrain in their sweep first laterally and then posteriorly to the point at which they extend directly into the internal occipital artery. In the AI? view (Fig. 4B), the posterior cerebral-internal occipital complex passes posteriorly and medially in a linear direction without any sharp angulation, implying a small brain stem. This finding, combined with the enlarged circle of Willis denoting a dilated third ventricle, localizes the obstruction to the aqueduct of Sylvius. Otherwise the AP arteriogram is indistinguishable from that of communicating hydrocephalus. The deep venous structures differ from those in communicating hydrocephalus only in that the veins of Rosenthal are medially displaced and follow an almost parallel course as they go to the vein of Galen. This indicates constriction of the brain stem by expansion of the lateral ventricles without expansion of the aqueduct. In the lateral projection (Fig, 4C), the arteriogram differs from communicating hydrocephalus only in two respects. The perforating branches of the posterior cerebral and posterior communicating arteries are directed superiorly and anteriorly and are stretched. In addition, the posterior cerebral-internal occipital complex follows an almost horizontal course from the origin of the posterior cerebral artery to the point at which the internal occipital artery bifurcates into the calcarine and cuneate branches. The lateral venous phase is characteristic and provides the most reliable diagnostic information ( Fig. 4D ) . The internal cerebral vein is displaced anteriorly and inferiorly, and the vein of Galen is lengthened and flattened. This results in an almost linear appearance of the internal cerebral vein and what appears to be direct continuation with the vein of Galen. This stretched and horizontal course of the two veins results from the anterior inferior displacement of the thalamus and basal ganglia by the expanded supratentorial ventricular system uncumbered by expansion in the infratentorial compartment. The course of the straight sinus is almost vertical. Inferior displacement of the lateral sinuses indicates a diminution in overall size of the posterior fossa. Atresia of the foramina of Luschka and Magendie (the Dandy-Walker cyst) is a most characteristic form of obstructive hydrocephalus in that it presents clinically as communicating hydrocephalus, but subsequently develops into a picture of obstructive hydrocephalus and posterior fossa space occupying lesion.15 The reason for this rests in the fact that the fourth ventricle is transformed into an enormous cyst which compresses the brain stem and displaces the cerebellar hemispheres superiorly and laterally, with resultant kinking of the aqueduct and secondary distension of the supratentorial ventricular system.” The angiographic diagnosis of the Dandy-Walker cyst depends on adequate visualization of the vascular structures in the posterior fossa. The arteriographic and venographic characteristics of the supratentorial compartment are diag-
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Fig. 5.-Atresia of the foramina of Luschka and Magendie (Dandy-Walker cyst). A. Arterial phase.
Large, spaceoccupying defect in posterior fossa displaces the arteries, occipital lobe, and cerebellar hemispheresanteriorly. B. Venous phase. Note displacement of the venous sinusesin the greatly enlarged posterior fossa.
nostic of hydrocephalus. However, when the vascular structures of the posterior fossa are demonstrated, it becomes possible to state that the fourth ventricle is maximally dilated. The AP arterial phase reveals that the posterior cerebral arteries pass directly laterally and form a right angle as they turn superiorly. These arteries never approach the midline, but rather pass directly upward to their termination. This failure of the posterior cerebral arteries to return to the midline as they course over the medial surface of the occipital lobe is probably the result of the superior displacement of the tentorium secondary to the cystic transformation of the fourth ventricle. The lateral arteriogram shows anterior displacement of the basilar artery so
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that it abuts upon the clivus (Fig, 5A). The posterior cerebral arteries follow a markedly superior and slightly posterior course since the occipital lobe is displaced superiorly and slightly anteriorly. The posteroinferior and anteroinferior cerebellar arteries outline the inferior surface of each cerebellar hemisphere and reveal it to maintain its normal convexity, though it is displaced anteriorly and superiorly. Similarly, the superior cerebellar arteries, which outline the superior surface of the vermis and cerebellar hemispheres, permit visualization of the convex superior surface of the cerebellar hemisphere displaced forward and upward through the tentorial opening. It is possible to see a very large space filling defect beneath the inferior surface of the cerebellar hemispheres because of the lack of vascular structures within it. This, in essence, is the cystic transformation of the fourth ventricle. AP projection of the venous phases reveals that the internal cerebral veins do not occupy their normal paramedian position, but that they are laterally displaced and follow a medial and superior course as they go to join the vein of Galen. This latter structure is impossible to identify in the AP projection, The lateral sinuses are elevated superiorly and laterally, the result of the expansile cystic mass within the posterior fossa. The torcular Herophili is located almost at the vertex of the skull. Lateral venograms exhibit anterior and superior displacement and elongation of the internal cerebral vein (Fig. 5B). The posterosuperior course of the vein of Galen as it passes to meet the superiorly displaced straight sinus is apparent, The latter structure is almost horizontal as it enters the elevated torcular Herophili. The lateral sinuses, which take their origin from the torcular, pass forward and downward in a rectilinear course to enter the sigmoid sinuses. These alterations in the sinus structures indicate the enormous increase in volume of the posterior fossa. Constrictive
Hydrocephalus
The angiographic criteria by which constrictive hydrocephalus is diagnosed consist of kinking of the vertebral arteries at the occipitocervical junction, angulation of the vertebral and the basilar arteries over the pontomedullary junction, and dislocation of the posterio inferior carotid artery into the cervical canal. The lateral projection is most valuable in the diagnosis of this type of hydrocephalus. Platybasiu and basilar impression. Theoretically, it is simple to distinguish between flattening of the base of the skull (platybasia) and a deformity of the squamous and basilar portions of the occipital bone (basilar impression), characterized by an indentation of the foramen magnum. At a clinical level, however, this is quite another matter since the symptoms caused by either basilar impression or platybasia are those of cervical cord, hind cranial nerve, and cerebellar dysfunction. In some patients, the deformity may be so severe as to produce a constrictive hydrocephalus. Consequently, the newborn with either of these anomalies may suffer repeated episodes of aspiration pneumonia, regurgitation through the nose, vocal cord paralysis, spontaneous nystagmus, irregular respiratory rate, and, on occasion, progressive increase in head size
ANTHONYJ.RAIMONDI
Fig. 6.-Agenesis of corpus callosum. A. Deformed third ventricle on pneu-
mography. B and C. Displacement the anterior cerebral artery.
of
with a clinical diagnosis of hydrocephalus. Laminagraphic studies may reveal the craniovertebral anomaly. Pancraniostenosis. The pancraniostenosis associated with Hurler’s disease and craniovertebral anomalies may cause a constrictive process in the basal cisterns at the level of the foramen magnum. This results in impairment of circulation of the CSF through the foramina of Luschka and Magendie and the basal cisterns. The resultant hydrocephalus is of the constrictive variety. OTHER CONGENITAL
ANOMALIES
COMMONLY
AS.WCIATED
WITH HYDROCEPHALUS
Agenesis of Corpus Callosum Of relatively common occurrence is agenesis of the corpus callosum. Though this may exist in an otherwise normal patient, it is commonly associated with the Dandy-Walker cyst, the Arnold-Chiari malformation, communicating hydrocephalus, craniovertebral anomalies, and other cerebral dysplasias. The deformity and elevation of the third ventricle which result from agenesis of the body of the corpus callosum cause characteristic displacement and elevation of the pericallosal artery (Fig. 6).
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Hydranencephaly The first definitive publication of hydranencephaly was that of Cruveilheir in 1833. Morphologic changes in this congenital anomaly are characterized by aplasia of the frontal lobes, parietal lobes, and the dorsolateral surface of the and medial surfaces of the temporal and temporal lobes. The inferior occipital lobes are preserved. The brain stem and cerebellum are generally intact. The result is a congenital malformation characterized by aplasia of that portion of the brain supplied by the anterior and middle cerebral arteries. It is precisely this discrete distribution which has led many authors to conclude that hydranencephaly is the result of a primary intrauterine vascular dysplasia of the internal carotid artery just distal to the origin of the anterior choroidal. Well over 90 per cent of the children born with this congenital malformation have an associated occlusion of the aqueduct which results in an accumulation
Fig. 7.-Hydranencephaly. A. Dysplasia of the
internal carotid arteries distal to the origin of the anterior choroidals. B. Shunting of contrast medium from the arterial directly into the deep venous system with premature filling of the straight and lateral sinuses.The brain stem is stained.
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ANTHONY
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of cerebral spinal fluid within the supratentorial compartment. Consequently, these children appear to have severe hydrocephalus. Careful neuroradiologic evaluation reveals that the primary problem is not hydrocephalus. In point of fact, hydranencephaly has been repeatedly confused with severe hydrocephalus. The air study reveals an almost total absence of cerebral mantle in the entire supratentorial compartment except for portions of the temporal and occipital lobes. Cerebral angiography (Fig. 7) reveals normal vertebral basilar, posterior cerebral, and anterior choroidal artery systems. However, the internal carotid artery is attenuated immediately superior to the anterior choroidal artery. On occasion, there may be a hypoplastic anterior cerebral artery or a truncated cerebral artery. The terminal branches of the middle and anterior cerebral arteries are absent. The stained basal ganglia, thalami, and brain stem often stand out in stark contrast to the absen cerebral hemispheres. There is early filling of the straight and lateral sinuses. Porencephaly Technically, porencephaly signifies a cystic area within the parenchyma of either cerebral hemisphere. The cyst is generally in contact with the subarachnoid space over the surface of the brain and with the ependyma of the ventricular lining. However, this does not always obtain. Many porencephalic cysts communicate with the ventricular system but not with the subarachnoid space. Occasionally the reverse is true. Therefore, one may not be sure whether a porencephalic cyst is present or absent on the basis of air studies alone. The angiographic picture of a porencephalic cyst is indistinguishable from that of any other nonvascular space occupying lesion of the cerebral hemispheres. However, since porencephaly is often associated with hydrocephalus of either communicating or obstructive variety, one may suspect the presence of a porencephalic cyst in a hydrocephalic child who has a nonvascular space occupying lesion in the cerebrum.
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5. DeLange, S. A.: Surgical treatment of progressive hydrocephahrs. Amsterdam, North-Holland Publishing Co., 1966, p. 134. 6. Dott, N. M.: A case of unilateral hydrcF cephahrs in an infant. Operation-cure. Brain 50:548,1927. 7. Faurk, C., and Gruson, B.: L’exploration radiologique des craniopharyngiomes de I’enfant (a propos de 17 observations). Ann. Radiol. 2: 197, 1959. 8. Laurence, K. M.: Some applications of the urinary phenolsulphonphthalein excretion test in hydrocephahrs and related conditions. Brain 82:551, 1959.
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ANOMALIES
9. Laurence, K. M., and Coates, S.: Further thoughts on the natural history of hydrocephalus. Develop. Med. Child. Neurol. 4:263,1962. 10. Matson, D. D.: Prenatal obstruction of the fourth ventricle. Amer. J. Roentgen. 76: 499,1956. 11. Paillas, J.-E., Bonnal, J., Berard-Badier, and Serratrice, G.: Les angiomes arterioveineux du cerveau chez l’enfant. Presse Med. 66:525,1958. 12. Picaza, J. A.: Cerebral angiography in children: an anatomoclinical evaluation. J. Neurosurg. 9:235, 1952. 13. Raimondi, A. J.: The neuroradiologic evaluation of craniocerebral injury in the newborn and infant. Minerva Pediat. 21.: 1251,1969. 14. Raimondi, A. J., Grossman, H. J., and Warren, S. A.: Intellectual levels of children with repeated shunt surgery for hydrocephalus. Presented to the Amer. Acad. Ped., Oct. 1968. 15. Raimondi, A. J., Samuelson, C. H., Yarzagaray, L., and Norton, Ft. F.: Angiographic diagnosis of communicating hydro-
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cephalus in the newborn. J. Neurosurg. 31: 550,1969. 16. Raimondi, A. J., and White, H.: Cerebral angiography in the newborn and infant: general principles. Ann. Radiol. 10: 147,1967. 17. Russell, D. 8: Observations on the Pathology of Hydrocephalus. London, Her Majesty’s Stationery Office, 1949, p. 152, 18. Taveras, J. M.: Neuroradiology in children. In Clinical Neuroradiology. New York, McGraw-Hill, 1966, pp. 359-399. 19. Taveras, J. M., and Poser, C. M.: Roentgenologic aspects of cerebral angiography in children. Amer. J. Roentgen. 82: 371,1959. 20. Tinel, J., de Martel, T., and Guillaume, J.: Hydrocephalie unilaterale. Intervention, Gukrison, Rev. Neurol. 1:415, 1932. 21. Tolosa, E.: L’exploration arteriographique dans l’hydrocephalie infantile. Semaine Hop. Paris 27:2401, 1951. 22. Walker, A. E.: A case of congenital artesia of the foramina of Luschka and Magendie: surgical cure. J. Neuropath. Exp. Neurol. 3:368, 1944.
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