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The skull in mongolism
cfi,.:. Radial. (1973) 24, 475-480 THE
SKULL
IN MONGOLISM
R. J. BURWOOD, I. R. S. GORDON, and R. D. T A F T
From the Department of Radiodiagnosis, Medical School, University of Bristol
Mongols have been shown to have a disproportionate increase in the basal angle relative to their cranial capacity. The measurement of Boogard's basal angle may therefore be used as a confirmatory sign in the radiological diagnosis of mongolism. Increase in the basal angle in a group of non-mongols with hydrocephalus and a cranial capacity above the 95th percentile has been shown to relate to the increase in capacity. The shape of the skull in mongolism is more variable than previous authors have suggested and a re-classification of cranial form in both normality and mongolism is submitted to the literature.
ABNORMAL radiological appearances in the skull have been described in patients with mongolism. The cardinal features of these abnormalities are moderate microcephaly, brachycephaly and hypoplasia of the cartilaginous bones of the cranial base and of the maxilla, (Ingalls, 1947). Retroflexion of the sphenoid and an upward slanting of the anterior cranial fossa have been reported by Benda (1953). Spitzer, Rabinowitch and Wybar (1961) have observed a diminished pneumatization of the paranasal sinuses in mongolism and these authors have also confirmed the presence of facial hypoplasia noted by Ingalls. This paper records the basal angle, cranial capacity and cranial shape in mongolism and the interrelationship of these measurements is discussed. Symmetrical abnormalities in the shape of the cranial vault in the normal population and in mongolism have been defined and classified. MATERIAL Thirty-six mongols of varying age and sex were studied. Twenty-two cases (16 males and 6 females) were obtained from the Bristol Children's Hospital with ages ranging from birth to 16 years. Seven cases (6 males and 1 female) were referred from Hortham Hospital, Almondsbury, and were aged between 16 and 20 years and a further seven adults (3 males and 4 females) aged between 21 and 40 years were referred from Stoke Park Hospital, Bristol. Patients obtained from the Bristol Children's Hospital possessed both the clinical and chromosomal abnormalities characteristic of mongolism. The remaining patients had the classic clinical stigmata of mongolism but no chromosome studies were made. Marked mental retardation was present
in all the cases reviewed. A control series of radiographs was studied consisting of 189 non-mongoloid children's skulls of comparable age and sex. This series contained groups of children with cranial capacities that were normal, raised (macrocephaly) and diminished (microcephaly). Conditions known or believed to cause platybasia were excluded from the control series (Burwood, 1970).
METHOD On each set of radiographs, the cranial capacity, basal angle and skull shape were recorded. The cranial capacity was obtained by the method o f Gordon (1966) from antero-posterior and lateral skull radiographs. Volume = (L × W × B) q- (L × W × H) × 0.1594ccs where L = greatest internal longitudinal diameter from the frontal bone to the occipital pole. B = vertical height from the deepest part of the inner table of the posterior fossa to the inner margin of the bregma. H = vertical height from the centre of the external auditory meatus to the most distal point on inner table of the vertex. W = greatest internal cranial width as meashred on the anteroposterior radiograph. 0.1594 is a correction factor. The capacities determined by this method were converted to percentile values for age and sex from charts compiled by one of the authors (Gordon 1966). Arbitrary limits at the 5th and 95th percentiles were taken and cranial capacities outside these limits were expressed in terms of their percentage volume difference below and above the arbitrary limits of normality (Tables 1A and 1B). The basal angle referred to was described by
475
476
CLINICAL
RADIOLOGY
TABLE IA THE BASALANGLE IN RELATIONTO CRANIAL CAPACITY
(36 MONGOLS)
Cranial capacity
No. of cases
Basal angle (arithmetic mean)
One standard deviation
12
137.9°
6.8°
24
140.0°
6.0°
6 10 19 46
146.0° 144.2° 141.6° 137.5°
3 "2°
3"6° 5.7° 6.8 °
69
132.1°
4.6°
39
133.2°
5.6°
Normal a. (5th-95th percentile)
Reduced b. (30~ below the 5th percentile)
TABLE 1B
(189 NON-MONGOLS)
Increased c. d. e. f.
(91 ~ or more over the 95th percentile) (61-90~ over the 95th percentile) (31-60 ~ over the 95th percentile) (1-30~ over the 95th percentile)
Normal g. (5th-95th percentile)
Reduced h. (1-30~ below the 5th percentile) B o o g a r d (1865) and is defined as the angle subtended at the centre o f the pituitary fossa by lines d r a w n f r o m the highest and most anterior point o f the naso-frontal suture (the nasion) and the lowermost tip o f the clivus (the basion) (Figs. 1 and 2). These points were determined on a true lateral skull radiograph with the n o r m a l b e a m centred to the external auditory meatus. Cases in which the endpoints were not clearly defined were discarded, with the exception o f neonates, in w h o m it was necessary to make estimated positionings o f the the unossified basion. In a few cases midline coronal and sagittal t o m o g r a p h y was performed for clinical reasons unconnected with this study. Cranial shape was ascertained f r o m the same skull radiographs by recording the dimensions o f height, width and length and by obtaining ratios between pairs o f these measurements ( G o r d o n 1970). The authors felt that some clarification in the formal nomenclature attributed to symmetrical abnormalities o f cranial shape was necessary, especially in regard to the short high head. The terms oxycephaly and acrocephaly are traditionally used to describe pointed skulls in association with craniostenosis, and it is proposed that these terms be restricted in ~his context. It is p r o p o s e d that turricephaly become the term o f choice to describe
those skulls merely possessing an increase in the normal height/length ratio. Skull shape is therefore re-classified as follows :1. Dolichocephaly (Gk. dolichos - long; kephale -head) A long, n a r r o w cranium (width/ length ratio - low). 2. Brachycephaly (Gk. brachys - short) A short, wide cranium (width/length ratio - high). 3. Scaphocephaly (Gk. skaphe - boat). A long, low cranium (height/length ratio - low). 4. Turricephaly (L. tuttis - tower). A short, high cranium (height/length ratio - high). 5. Platycephaly (Gk, platys - broad). A low, wide cranium (height/width ratio - low). 6. Stelecephaly* (Gk. stele - pillar). A narrow, high cranium (height/width ratio - high). 7. Normal All ratios within normal limits.
8. Pointed Skulls. POINTED SKULLS
(a) Oxycephaly (Gk. oxys - sharp) (b) Acrycephaly (Gk. a k r o n - extremity) In order for a skull to be classified as o f abnormal * Stelecephaly is a new term introduced to the medical literature. It defines that shape of skull in which there is an increase in the height/width ratio.
THE
SKULL
477
IN MONGOLISM
On
FXG. 1
Normal control The radiographic positioning of end-points in the measurement of Boogard's basal angle.
FIG. 2
Normal control. The basal angle remains within the normal range i.e. 132"1 ° -T- one standard deviation of 4.6 °.
478
CLINICAL
• .
RADIOLOGY
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3
Mongolism. In a skull o f normal or reduced capacity, increase in the basal angle to beyond 1 4 0 ° is highly suggestive o f Mongolism. TABLE 2 THE
RELATIONSHIP
OF
CRANIAL
CAPACITY
TO
SHAPE
IN MONGOLISM
(36 mongols) A) C R A N I A OF N O R M A L C A P A C I T Y (12 cases)
Cranialshape
No. ofcases
Normal Brachycephaly Turricepbaly Platycephaly Stelecephaly
Percentage o f group 33% 33~
17%
8% 8%
B) CRANIAoEREDUCEDCAPACITY (24 cases below the 5th percentile) Cranial shape
Normal Brachycephaly Turricephaly Platycephaly
No. ofeases
Percentage of group
13 5 5 i
54% 21~/o 21~ 4%
shape, the ratio of the determined parameters should lie beyond the 5th or 95th percentiles for the normal distribution of that ratio for the known age (Gordon, 1968). RESULTS See Tables 1, 2, 3. DISCUSSION Size.--The reported reduction of cranial capacity in mongolism (Irlgalls, 1947) has been confirmed. In the present study no mongol skull lay above the 50th percentile for the age and sex of the patient and 24 (66.7%) patients with cranial capacities below the 5th percentile were classified as microcephalic. (Table 1A). The basal angle in mongolism (Fig. 3) was shown to be significantly elevated as compared with nonmongol controls of both similar cranial capacity (p < 0.001) and reduced cranial capacity (p < 0.001). When the basal angles in the controls of normal and reduced cranial capacity were compared, no significant difference of the mean values could be established (p > 0.05). Alteration of the basal angle with growth has been held to be insignificant after the neonatal period a.
Cranial
THE SKULL IN MONGOLISM
479
TABLE 3 THE BASALANGLE IN SKULLSOF ABNORMALSHAPE
(19 MONGOLSAND93 SELECTEDNoN-MoNGOLS)
Cranial shape
Number Ceases Non mongo&
Dolichocephaly Brachycephaly Scaphocephaly Turricephaly Platycephaly Stelecephaly
20 20 17 10 18 8
(Stamrud, 1959) but it is clear that the angle bears a close relationship to the cranial capacity when this is considerably increased (Table 1B). Increase of the basal angle with increasing capacity was independent of age in the range from birth to fourteen years. No similar reduction in the basal angle could be detected in normal skulls of diminished capacity. Basal angles found in the mongol series were similar to values recorded in non-mongol children with greatly increased cranial capacities (Tables 1h and 1B). b. Cranial Shape.--No significant difference in the basal angle could be detected between mongols of abnormal cranial shape and a highly selected group of non-mongols with similar deformities (Table 3), but this may reflect the small numbers in each of the subdivisions of shape. In the present series, 4 (11 ~ ) mongols were shown to have heads that were both of-normal capacity and normal shape. Thirteen (36 ~ ) demonstrated no other, radiological abnormality than microcephaly. Of those mongols with abnormally shaped skulls, 9 ( 2 5 ~ ) demonstrated brachycephaly, 7 (19.4~) turricephaly and 3 (8.3~) had either platycephaly or stelecephaly. The definite incidence of turricephaly and less significant numbers with platy- and stelecephaly are important in that previously brachycephaly alone had been reported in association with mongolism (Ingalls, 1947). The mean cephalic index (width/length ratio) for the mongol series was high (0.83) as compared with the normal mean value of 0-78. The figure in this series is in close agreement with that previously reported by Penrose (1961) of 0.82. Roche (1966) however, held that apart from the reduced cranial capacity, the mongol skull was usually of normal form. This opinion is not substantiated by other investigators. In this study it is interesting to note that mongol skulls of normal capacity had a higher incidence of
mongols
Basal angle (mean values) Non mongols
133.1° 134.0° 135.0° 134'6" 136.3° 129.5°
mongols
138° 136.7° 138° 135°
abnormal shape than did those with a reduced capacity, but there was no statistical indication that specific abnormalities of cranial shape were a function of that capacity. On the hypothesis that long skulls (dolicho- and scaphocephaly) might tend to have larger basal angles than short skulls (brachy- and turricephaly), the values in both groups were compared. The ranges for the basal angle in brachycephaly (120 ° 140 °) previously reported by McRae (1960) conformed to this hypothesis, but these values were not corroborated in the present series. In this study the basal angle in twenty non-mongol skulls with brachycephaly was shown to have an arithmetic mean value of 134 ° with a range of values between 127 ° and 140 °, and seventeen non-mongol children with scaphocephaly were shown to have a range of between 130 ° and 144 °, with an arithmetic mean value of 135 ° (Table 3). We would accept McRae's figures in scaphocephaly but can find no evidence of a reduction in the basal angle in brachycephaly.
Acknowledgements.--Drs. R. J. Burwood and R. D. Taft have been indebted to the Medical Research Council for grants enabling them to pursue studies into anomalies of the cranial base. Tile authors thank Professor J. H. Middlemiss for his help and advice and Drs. J. Jancar, Stoke Park Hospital and A. C. Fairburn, Hortham Hospital, Almondsbury for their co-operation in providing the material for this study. Dr. C. Pennock, Bristol Royal Infirmary is thanked for his statistical analysis of the results and we are grateful to Mrs. V. Young for the preparation of the manuscript. Finally, we thank the University of Bristol for permission to include material from a doctoral thesis (R.J.B.) entitled "The Cranio-Cervical Junction". REFERENCES BEND& C. E. (1953). "Research in congenital acromicria (mongolism) and its treatment." Quarterly Review of Paediatrics, 8, 79-96.
480
CLINICAL
BOOGARD,J. A. (1865). "Geneeskde indrukking grand alakle van den schedel door de verrekolom hare oorzaken en gerologen." Nederlandse Ti]dschrift voor Geneeskunde, 2, 81. BoRwoon, R. J. (1970). "The Cranio-Cervical Junction." Thesis. University of Bristol. GORDON, I. R. S. (1966). "Measurement of cranial capacity in children." British Journal of Radiology, 39, 377-381. GORDON, I. R. S. (1970). "Microcephaly and Craniostenosis". Clinical Radiology, 21, 19-31. INGALLS, T. H. (1947). "Etiology of mongolism; epidemiologic and teratologic implications." American Journal of Diseases of Childhood, 74, 147-165. INGALLS, T. H. (1947). "Pathogenesis of mongolism".
BOOK
RADIOLOGY
American Journal of Diseases of Childhood, 73, 279-292. McRAE, D. L. (1960). "The Caldwell Lecture". "The significance of abnormalities of the cervical spine." American Journal of Roentgenology, 84, 3-25. PENROSE, L. S. (1961). "Mongolism". British Medical Bulletin, 17, 184-189. ROCEm, A. F. (1966). "The cranium in mongolism". Acta Neurologica Scandinavica, 42, 62-78. SPITZER, R., RABINOWITCH,J. Y. & WYBAR,K. C. (1961). " A study of the abnormalities of tile skull, teeth and lenses in mongolism." Canadian Medical Association Journal, 84, 567-572. STAMRUD, J. (1959). "External and internal cranial base." Acta Odontologica Scandinavica, 17, 239.
REVIEW
Cardiac Clinicopathological Conferences of the Massachusetts General Hospital. Editors: BENJAMIN CASTELMAN and ROMAN W. DE SANCTIS. Publishers: Little, Brown and Company, Boston, Massachusetts, 1972. 440 pages. In this volume, 50 cases have been collected together from the many hundreds published in the New England Journal of Medicine since 1955. These 50 cases all have major involvement of the cardiovascular system and have been particularly chosen because of the teaching value of the discussions and of the post mortem findings. Presentation begins with the clinical history and the physical examination and this is followed by investigations including good reproductions of the electrocardiogram and the chest radiograph. The diagnosis is then discussed by an invited physician who has not seen the patient and, after a full presentation of his deductive reasoning, he comes to a clinical diagnosis. The findings at post mortem are then presented and illustrated. All the case histories and discussions make excellent reading and much useful information is obtained from a close study of the clinician's reasons for making Iris diagnosis. This particular form of presentation is of particular value to the radiologist interested in cardiac radiology because it provides him with a total picture of the patient's iliness while at the same time showing the value of radiological techniques (particularly chest radiography and angiocardiography) in diagnosis and management. The quality of the paper is high and tile reproduction of most radiological material is more than adequate. There is no index and this collection of case histories was not intended as a text book. Furthermore, advances in cardiology over the 14 years or so since the presentation of' the first of these clinico-pathological conferences make some of the material out of date. This has been recognised and remedied by an addendum at the end of most of the case presentations. Before studying each case, it is important to note the date of the original presentation, otherwise some of the statements will appear disconcerting and this feeling of confusion in not cleared until the addendum is reached at the very end of each article.
The standard of investigation and discussion is very high in every case, and this modern collection of ctinieo-pathological conferences is the best available for diseases of the cardiovascular system. JAMESFLEMING
Radiological Diagnosis of Digestive Tract Disorders in the New Born. By CREMIN, CYWES and Lovw. Published by the Butterworth Group. Price £5.80. This book covers the field indicated by its title in a concise but highly informative manner. The radiologist who does not routinely deal with alhnentary problems in the new born will find this book of great value. The techniques of examination, the likely findings, and their interpretation, are clearly described. The radiographs are well chosen and, in the main, adequately reproduced. The line drawings are excellent. The combined authorship by a radiologist and two surgeons provides an excellent balance between the clinical and technical aspects of the subject. In a few respects the recommendations in this book are not in accordance with the reviewer's practice. In chapter 2 it is suggested that three plain films of the abdomen should always be taken, an inverted film is suggested in addition to the conventional erect and supino views. It is thought better that the inverted film should only be taken after the initial erect and supine have been inspected, in an cndeavour to decrease radiation. The authors suggest that the value of hypertonic water soluble contrast enemata in obstruction due to meconium ileus and milk obstruction is a technique that requires further evaluation. It is, however, now widely used and with proper attention to selection of patients and the prevention of dehydration, will provide a satisfactory alternative to surgery in many cases. These points, however, are based more on local variations of practice than on any major criticism of the book. As noted above, it provides an excellent review of technique and findings in its field. R. K. LEVlCK
SKULL
IN MONGOLISM
R. J. BURWOOD, I. R. S. GORDON, and R. D. T A F T
From the Department of Radiodiagnosis, Medical School, University of Bristol
Mongols have been shown to have a disproportionate increase in the basal angle relative to their cranial capacity. The measurement of Boogard's basal angle may therefore be used as a confirmatory sign in the radiological diagnosis of mongolism. Increase in the basal angle in a group of non-mongols with hydrocephalus and a cranial capacity above the 95th percentile has been shown to relate to the increase in capacity. The shape of the skull in mongolism is more variable than previous authors have suggested and a re-classification of cranial form in both normality and mongolism is submitted to the literature.
ABNORMAL radiological appearances in the skull have been described in patients with mongolism. The cardinal features of these abnormalities are moderate microcephaly, brachycephaly and hypoplasia of the cartilaginous bones of the cranial base and of the maxilla, (Ingalls, 1947). Retroflexion of the sphenoid and an upward slanting of the anterior cranial fossa have been reported by Benda (1953). Spitzer, Rabinowitch and Wybar (1961) have observed a diminished pneumatization of the paranasal sinuses in mongolism and these authors have also confirmed the presence of facial hypoplasia noted by Ingalls. This paper records the basal angle, cranial capacity and cranial shape in mongolism and the interrelationship of these measurements is discussed. Symmetrical abnormalities in the shape of the cranial vault in the normal population and in mongolism have been defined and classified. MATERIAL Thirty-six mongols of varying age and sex were studied. Twenty-two cases (16 males and 6 females) were obtained from the Bristol Children's Hospital with ages ranging from birth to 16 years. Seven cases (6 males and 1 female) were referred from Hortham Hospital, Almondsbury, and were aged between 16 and 20 years and a further seven adults (3 males and 4 females) aged between 21 and 40 years were referred from Stoke Park Hospital, Bristol. Patients obtained from the Bristol Children's Hospital possessed both the clinical and chromosomal abnormalities characteristic of mongolism. The remaining patients had the classic clinical stigmata of mongolism but no chromosome studies were made. Marked mental retardation was present
in all the cases reviewed. A control series of radiographs was studied consisting of 189 non-mongoloid children's skulls of comparable age and sex. This series contained groups of children with cranial capacities that were normal, raised (macrocephaly) and diminished (microcephaly). Conditions known or believed to cause platybasia were excluded from the control series (Burwood, 1970).
METHOD On each set of radiographs, the cranial capacity, basal angle and skull shape were recorded. The cranial capacity was obtained by the method o f Gordon (1966) from antero-posterior and lateral skull radiographs. Volume = (L × W × B) q- (L × W × H) × 0.1594ccs where L = greatest internal longitudinal diameter from the frontal bone to the occipital pole. B = vertical height from the deepest part of the inner table of the posterior fossa to the inner margin of the bregma. H = vertical height from the centre of the external auditory meatus to the most distal point on inner table of the vertex. W = greatest internal cranial width as meashred on the anteroposterior radiograph. 0.1594 is a correction factor. The capacities determined by this method were converted to percentile values for age and sex from charts compiled by one of the authors (Gordon 1966). Arbitrary limits at the 5th and 95th percentiles were taken and cranial capacities outside these limits were expressed in terms of their percentage volume difference below and above the arbitrary limits of normality (Tables 1A and 1B). The basal angle referred to was described by
475
476
CLINICAL
RADIOLOGY
TABLE IA THE BASALANGLE IN RELATIONTO CRANIAL CAPACITY
(36 MONGOLS)
Cranial capacity
No. of cases
Basal angle (arithmetic mean)
One standard deviation
12
137.9°
6.8°
24
140.0°
6.0°
6 10 19 46
146.0° 144.2° 141.6° 137.5°
3 "2°
3"6° 5.7° 6.8 °
69
132.1°
4.6°
39
133.2°
5.6°
Normal a. (5th-95th percentile)
Reduced b. (30~ below the 5th percentile)
TABLE 1B
(189 NON-MONGOLS)
Increased c. d. e. f.
(91 ~ or more over the 95th percentile) (61-90~ over the 95th percentile) (31-60 ~ over the 95th percentile) (1-30~ over the 95th percentile)
Normal g. (5th-95th percentile)
Reduced h. (1-30~ below the 5th percentile) B o o g a r d (1865) and is defined as the angle subtended at the centre o f the pituitary fossa by lines d r a w n f r o m the highest and most anterior point o f the naso-frontal suture (the nasion) and the lowermost tip o f the clivus (the basion) (Figs. 1 and 2). These points were determined on a true lateral skull radiograph with the n o r m a l b e a m centred to the external auditory meatus. Cases in which the endpoints were not clearly defined were discarded, with the exception o f neonates, in w h o m it was necessary to make estimated positionings o f the the unossified basion. In a few cases midline coronal and sagittal t o m o g r a p h y was performed for clinical reasons unconnected with this study. Cranial shape was ascertained f r o m the same skull radiographs by recording the dimensions o f height, width and length and by obtaining ratios between pairs o f these measurements ( G o r d o n 1970). The authors felt that some clarification in the formal nomenclature attributed to symmetrical abnormalities o f cranial shape was necessary, especially in regard to the short high head. The terms oxycephaly and acrocephaly are traditionally used to describe pointed skulls in association with craniostenosis, and it is proposed that these terms be restricted in ~his context. It is p r o p o s e d that turricephaly become the term o f choice to describe
those skulls merely possessing an increase in the normal height/length ratio. Skull shape is therefore re-classified as follows :1. Dolichocephaly (Gk. dolichos - long; kephale -head) A long, n a r r o w cranium (width/ length ratio - low). 2. Brachycephaly (Gk. brachys - short) A short, wide cranium (width/length ratio - high). 3. Scaphocephaly (Gk. skaphe - boat). A long, low cranium (height/length ratio - low). 4. Turricephaly (L. tuttis - tower). A short, high cranium (height/length ratio - high). 5. Platycephaly (Gk, platys - broad). A low, wide cranium (height/width ratio - low). 6. Stelecephaly* (Gk. stele - pillar). A narrow, high cranium (height/width ratio - high). 7. Normal All ratios within normal limits.
8. Pointed Skulls. POINTED SKULLS
(a) Oxycephaly (Gk. oxys - sharp) (b) Acrycephaly (Gk. a k r o n - extremity) In order for a skull to be classified as o f abnormal * Stelecephaly is a new term introduced to the medical literature. It defines that shape of skull in which there is an increase in the height/width ratio.
THE
SKULL
477
IN MONGOLISM
On
FXG. 1
Normal control The radiographic positioning of end-points in the measurement of Boogard's basal angle.
FIG. 2
Normal control. The basal angle remains within the normal range i.e. 132"1 ° -T- one standard deviation of 4.6 °.
478
CLINICAL
• .
RADIOLOGY
..-
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.....
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- .-
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FIG.
:
-
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3
Mongolism. In a skull o f normal or reduced capacity, increase in the basal angle to beyond 1 4 0 ° is highly suggestive o f Mongolism. TABLE 2 THE
RELATIONSHIP
OF
CRANIAL
CAPACITY
TO
SHAPE
IN MONGOLISM
(36 mongols) A) C R A N I A OF N O R M A L C A P A C I T Y (12 cases)
Cranialshape
No. ofcases
Normal Brachycephaly Turricepbaly Platycephaly Stelecephaly
Percentage o f group 33% 33~
17%
8% 8%
B) CRANIAoEREDUCEDCAPACITY (24 cases below the 5th percentile) Cranial shape
Normal Brachycephaly Turricephaly Platycephaly
No. ofeases
Percentage of group
13 5 5 i
54% 21~/o 21~ 4%
shape, the ratio of the determined parameters should lie beyond the 5th or 95th percentiles for the normal distribution of that ratio for the known age (Gordon, 1968). RESULTS See Tables 1, 2, 3. DISCUSSION Size.--The reported reduction of cranial capacity in mongolism (Irlgalls, 1947) has been confirmed. In the present study no mongol skull lay above the 50th percentile for the age and sex of the patient and 24 (66.7%) patients with cranial capacities below the 5th percentile were classified as microcephalic. (Table 1A). The basal angle in mongolism (Fig. 3) was shown to be significantly elevated as compared with nonmongol controls of both similar cranial capacity (p < 0.001) and reduced cranial capacity (p < 0.001). When the basal angles in the controls of normal and reduced cranial capacity were compared, no significant difference of the mean values could be established (p > 0.05). Alteration of the basal angle with growth has been held to be insignificant after the neonatal period a.
Cranial
THE SKULL IN MONGOLISM
479
TABLE 3 THE BASALANGLE IN SKULLSOF ABNORMALSHAPE
(19 MONGOLSAND93 SELECTEDNoN-MoNGOLS)
Cranial shape
Number Ceases Non mongo&
Dolichocephaly Brachycephaly Scaphocephaly Turricephaly Platycephaly Stelecephaly
20 20 17 10 18 8
(Stamrud, 1959) but it is clear that the angle bears a close relationship to the cranial capacity when this is considerably increased (Table 1B). Increase of the basal angle with increasing capacity was independent of age in the range from birth to fourteen years. No similar reduction in the basal angle could be detected in normal skulls of diminished capacity. Basal angles found in the mongol series were similar to values recorded in non-mongol children with greatly increased cranial capacities (Tables 1h and 1B). b. Cranial Shape.--No significant difference in the basal angle could be detected between mongols of abnormal cranial shape and a highly selected group of non-mongols with similar deformities (Table 3), but this may reflect the small numbers in each of the subdivisions of shape. In the present series, 4 (11 ~ ) mongols were shown to have heads that were both of-normal capacity and normal shape. Thirteen (36 ~ ) demonstrated no other, radiological abnormality than microcephaly. Of those mongols with abnormally shaped skulls, 9 ( 2 5 ~ ) demonstrated brachycephaly, 7 (19.4~) turricephaly and 3 (8.3~) had either platycephaly or stelecephaly. The definite incidence of turricephaly and less significant numbers with platy- and stelecephaly are important in that previously brachycephaly alone had been reported in association with mongolism (Ingalls, 1947). The mean cephalic index (width/length ratio) for the mongol series was high (0.83) as compared with the normal mean value of 0-78. The figure in this series is in close agreement with that previously reported by Penrose (1961) of 0.82. Roche (1966) however, held that apart from the reduced cranial capacity, the mongol skull was usually of normal form. This opinion is not substantiated by other investigators. In this study it is interesting to note that mongol skulls of normal capacity had a higher incidence of
mongols
Basal angle (mean values) Non mongols
133.1° 134.0° 135.0° 134'6" 136.3° 129.5°
mongols
138° 136.7° 138° 135°
abnormal shape than did those with a reduced capacity, but there was no statistical indication that specific abnormalities of cranial shape were a function of that capacity. On the hypothesis that long skulls (dolicho- and scaphocephaly) might tend to have larger basal angles than short skulls (brachy- and turricephaly), the values in both groups were compared. The ranges for the basal angle in brachycephaly (120 ° 140 °) previously reported by McRae (1960) conformed to this hypothesis, but these values were not corroborated in the present series. In this study the basal angle in twenty non-mongol skulls with brachycephaly was shown to have an arithmetic mean value of 134 ° with a range of values between 127 ° and 140 °, and seventeen non-mongol children with scaphocephaly were shown to have a range of between 130 ° and 144 °, with an arithmetic mean value of 135 ° (Table 3). We would accept McRae's figures in scaphocephaly but can find no evidence of a reduction in the basal angle in brachycephaly.
Acknowledgements.--Drs. R. J. Burwood and R. D. Taft have been indebted to the Medical Research Council for grants enabling them to pursue studies into anomalies of the cranial base. Tile authors thank Professor J. H. Middlemiss for his help and advice and Drs. J. Jancar, Stoke Park Hospital and A. C. Fairburn, Hortham Hospital, Almondsbury for their co-operation in providing the material for this study. Dr. C. Pennock, Bristol Royal Infirmary is thanked for his statistical analysis of the results and we are grateful to Mrs. V. Young for the preparation of the manuscript. Finally, we thank the University of Bristol for permission to include material from a doctoral thesis (R.J.B.) entitled "The Cranio-Cervical Junction". REFERENCES BEND& C. E. (1953). "Research in congenital acromicria (mongolism) and its treatment." Quarterly Review of Paediatrics, 8, 79-96.
480
CLINICAL
BOOGARD,J. A. (1865). "Geneeskde indrukking grand alakle van den schedel door de verrekolom hare oorzaken en gerologen." Nederlandse Ti]dschrift voor Geneeskunde, 2, 81. BoRwoon, R. J. (1970). "The Cranio-Cervical Junction." Thesis. University of Bristol. GORDON, I. R. S. (1966). "Measurement of cranial capacity in children." British Journal of Radiology, 39, 377-381. GORDON, I. R. S. (1970). "Microcephaly and Craniostenosis". Clinical Radiology, 21, 19-31. INGALLS, T. H. (1947). "Etiology of mongolism; epidemiologic and teratologic implications." American Journal of Diseases of Childhood, 74, 147-165. INGALLS, T. H. (1947). "Pathogenesis of mongolism".
BOOK
RADIOLOGY
American Journal of Diseases of Childhood, 73, 279-292. McRAE, D. L. (1960). "The Caldwell Lecture". "The significance of abnormalities of the cervical spine." American Journal of Roentgenology, 84, 3-25. PENROSE, L. S. (1961). "Mongolism". British Medical Bulletin, 17, 184-189. ROCEm, A. F. (1966). "The cranium in mongolism". Acta Neurologica Scandinavica, 42, 62-78. SPITZER, R., RABINOWITCH,J. Y. & WYBAR,K. C. (1961). " A study of the abnormalities of tile skull, teeth and lenses in mongolism." Canadian Medical Association Journal, 84, 567-572. STAMRUD, J. (1959). "External and internal cranial base." Acta Odontologica Scandinavica, 17, 239.
REVIEW
Cardiac Clinicopathological Conferences of the Massachusetts General Hospital. Editors: BENJAMIN CASTELMAN and ROMAN W. DE SANCTIS. Publishers: Little, Brown and Company, Boston, Massachusetts, 1972. 440 pages. In this volume, 50 cases have been collected together from the many hundreds published in the New England Journal of Medicine since 1955. These 50 cases all have major involvement of the cardiovascular system and have been particularly chosen because of the teaching value of the discussions and of the post mortem findings. Presentation begins with the clinical history and the physical examination and this is followed by investigations including good reproductions of the electrocardiogram and the chest radiograph. The diagnosis is then discussed by an invited physician who has not seen the patient and, after a full presentation of his deductive reasoning, he comes to a clinical diagnosis. The findings at post mortem are then presented and illustrated. All the case histories and discussions make excellent reading and much useful information is obtained from a close study of the clinician's reasons for making Iris diagnosis. This particular form of presentation is of particular value to the radiologist interested in cardiac radiology because it provides him with a total picture of the patient's iliness while at the same time showing the value of radiological techniques (particularly chest radiography and angiocardiography) in diagnosis and management. The quality of the paper is high and tile reproduction of most radiological material is more than adequate. There is no index and this collection of case histories was not intended as a text book. Furthermore, advances in cardiology over the 14 years or so since the presentation of' the first of these clinico-pathological conferences make some of the material out of date. This has been recognised and remedied by an addendum at the end of most of the case presentations. Before studying each case, it is important to note the date of the original presentation, otherwise some of the statements will appear disconcerting and this feeling of confusion in not cleared until the addendum is reached at the very end of each article.
The standard of investigation and discussion is very high in every case, and this modern collection of ctinieo-pathological conferences is the best available for diseases of the cardiovascular system. JAMESFLEMING
Radiological Diagnosis of Digestive Tract Disorders in the New Born. By CREMIN, CYWES and Lovw. Published by the Butterworth Group. Price £5.80. This book covers the field indicated by its title in a concise but highly informative manner. The radiologist who does not routinely deal with alhnentary problems in the new born will find this book of great value. The techniques of examination, the likely findings, and their interpretation, are clearly described. The radiographs are well chosen and, in the main, adequately reproduced. The line drawings are excellent. The combined authorship by a radiologist and two surgeons provides an excellent balance between the clinical and technical aspects of the subject. In a few respects the recommendations in this book are not in accordance with the reviewer's practice. In chapter 2 it is suggested that three plain films of the abdomen should always be taken, an inverted film is suggested in addition to the conventional erect and supino views. It is thought better that the inverted film should only be taken after the initial erect and supine have been inspected, in an cndeavour to decrease radiation. The authors suggest that the value of hypertonic water soluble contrast enemata in obstruction due to meconium ileus and milk obstruction is a technique that requires further evaluation. It is, however, now widely used and with proper attention to selection of patients and the prevention of dehydration, will provide a satisfactory alternative to surgery in many cases. These points, however, are based more on local variations of practice than on any major criticism of the book. As noted above, it provides an excellent review of technique and findings in its field. R. K. LEVlCK