A Comparison of Radiological andPalaeopathological Diagnostic Criteriafor Hyperostosis Frontalis Interna

GERALDINE BARBER,1 IAIN WATT2 AND JULIET ROGERS1

1RheumatologyUnit, Department ofMedicine, BristolRoyal Infirmary, BristolBS2 8HW,UK; and 2Department of Radiology, Bristol Royal Infirmary, Bristol BS8 8HW, UK

ABSTRACT Hyperostosis frontalis interna (HFI) is a common clinical ®nding in post-menopausal women,less often in men. The characteristic billowing symmetrical new bone formation is found on theendocranial surface of the skull and rarely causes any signi®cant symptoms. In clinicalmedicine HFI is diagnosed from its X-ray appearance, whereas in palaeopathology it isdiagnosed by direct observation of the skull. There are no standard palaeopathological criteriato diagnose HFI.

In past populations HFI appears to be much less common than today, with modernprevalences of up to 70 per cent of women over 40 affected, compared with archaeologicalprevalences of between 1 and 4 per cent. This discrepancy has been attributed to a youngermean age at death in ancient populations. This study aims to test the hypothesis that thedifference in prevalence may be due in part to the differential nature of diagnosis between thetwo disciplines. A sample of 85 skulls was X-rayed, and the presence of HFI was recordedusing radiological criteria. Using this method the results showed a marked increase in thenumber of cases of HFI to 31 per cent in females in the ancient population. # 1997 by JohnWiley & Sons, Ltd.

Int. J. Osteoarchaeol., 7: 157±164 (1997)No. of Figures: 4. No. of Tables: 3. No. of References: 13.

Key words: hyperostosis frontalis interna; age; X-ray; palaeopathology; skull; diagnosticcriteria.

Introduction

Hyperostosis frontalis interna (HFI) is a commonX-ray ®nding in modern clinical practice,appearing visually on a plain X-ray as billowingsymmetrical new bone on the inner table of thefrontal (and occasionally the parietal) bone. Itappears more commonly in females than males,with an estimated male:female ratio of 1:9 and apeak incidence in modern patients in the 40±60year age group.1 This phenomenon can vary inprevalence between populations, with ®gures ofanything from 22 to 70 per cent of the populationbeing affected (Table 1).

Clinically the presence of HFI has a slightassociation with Morgagni's syndrome (alsoknown as MSMÐMorgagni±Stewart±Morel syn-drome), which is a hormonal disorder presentingwith, among others, symptoms of obesity,

International Journal of Osteoarchaeology, Vol. 7: 157±164 (1997)

CCC 1047±482X/97/020157±08$17.50 Received 1 August 1996# 1997 by John Wiley & Sons, Ltd. Accepted 23 September 1996

*Correspondence to: G. Barber.

Table 1. Comparison of modern and archaeological preva-lences of hyperostosis frontalis interna.

Modern prevalence %Archaeologicalprevalence %

Home for the aged, USA(Gershon-Cohen, 1953)2 62

St Andrew Fishergate,York (Stroud, 1993)3 1

Elderly USA citizens(Henschen et al, 1949)4 40

Poundbury, England(Molleson, 1993)5 4

Normal citizens aged 15±70+ years, Finland (Salmi

et al, 1962)1 22

Pompeii, Italy (Lazer,1994)6

10

hirsutism and mental retardation;7,8 mostpatients with HFI are asymptomatic, however.9

In archaeological material the prevalence of HFIappears to be relatively low (Table 1). Cases arediagnosed by direct visual observation, and thereare no standard diagnostic criteria. Those sitereports that mention cases of HFI usually have afew individuals affected, and give prevalences ofbetween 1 and 4 per cent of the population. Thedifference between ancient and modern popu-lations is striking, and has been commented uponby several researchers.10,11 Armelagos suggests that`this high frequency in contemporary populationsmay re¯ect an increase in longevity'. Others agreewith this argument, but some go much further.Lazer6 is quoted in the New Scientist as interpretingthe slightly higher prevalence of 10 per cent for thepopulation of Pompeii as evidence that `a substantialminority . . . were obese, a bit on the hairy side andwould have suffered from headaches and a form ofdiabetes'. Clearly this sort of statement (which ofcourse may have been misquoted) does not help thediscussion. Anderson11 replied to this article in aletter where he suggests that the `paucity ofarchaeological cases is rather surprising'. Heattributes this again to a lower life expectancy inthe past, but he also points to the fact that outwardlynormal crania may not be subject to X-rayexamination. A recent study by Phillips12 ofskeletons from a nineteenth century Americanhospital population from Oneida County producedprevalences of closer to those of modern samples,but he attributes this high rate to the populationstudied having a higher proportion of MSMsufferers, the hospital in question having functionedpartly as an asylum.

It therefore would seem that there is a differencebetween the prevalence of HFI in past populationsand modern ones. However, as no standardmethod is used, nor one which has been comparedto the radiological criteria currently in use, it maybe that some percentage of the difference may beaccounted for in this way. It was proposedtherefore to undertake a study to grade anarchaeological sample of crania for HFI using exactradiological grading, and to compare the preva-lence with that of modern individuals. In additionthe direct visual appearance of the endocranialsurface of the graded frontal bones was used toprovide a standard for palaeopathological use.

Materials and methods

The sample

A random sample of 85 complete adult skullsfrom St Peter's Church, Barton-on-Humber werechosen for this study, consisting of 37 males, 42females and 6 of unknown sex (shown hereafteras ?). The dates of the individuals ranged fromthe twelfth to the eighteenth centuries. All theskeletons were aged using standard anthropolo-gical methods, the mean ages being as 40 yearsfor males and 35 years for females respectively.

Each skull was radiographed using standardanterio-posterio (AP) and lateral X-rays. Thesewere then graded (blind to the age and sex ofeach individual) for the presence of HFI usingthe radiological criteria of Littlejohn et al13 bythe second author as follows: 0, no new boneformation; 1, early endosteal new bone on theinner table; 2, more advanced endosteal bonewith a bosselated appearance; 3, severe changewith much irregularity and increased thickness.

Each skull was then observed directly using apen torch through the foramen magnum. One ofthe best examples of each of the skulls graded 0to 3 was then cut open to reveal the direct visualappearance to provide a directly comparablevisual standard (Figures 1±4).

Results

Observer error

A random subsample of eight of the radiographswere re-examined a week later by the sameobserver, blind to the original score, to checkobserver error. All the X-rays were given thesame score on both occasions.

The scores for all of the individuals in thesample are given in Table 2. Those aged over 45are also shown separately in Table 3. The resultsshow that no male was given a grade of above 1,but 19% of females had a score of 2 or above. Ahigher percentage of women over 45 are affectedcompared with those under.

158 G. Barber, I. Watt and J. Rogers

INT. J. OSTEOARCHAEOL., Vol. 7: 157±164 (1997) # 1997 by John Wiley & Sons, Ltd.

Diagnostic Criteria for Hyperostosis Frontalis Interna 159

# 1997 by John Wiley & Sons, Ltd. INT. J. OSTEOARCHAEOL., Vol. 7: 157±164 (1997)

Figure 1. Grade 0. X-ray and photographic appearance.

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INT. J. OSTEOARCHAEOL., Vol. 7: 157±164 (1997) # 1997 by John Wiley & Sons, Ltd.

Figure 2. Grade 1. X-ray and photographic appearance.

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# 1997 by John Wiley & Sons, Ltd. INT. J. OSTEOARCHAEOL., Vol. 7: 157±164 (1997)

Figure 3. Grade 2. X-ray and photographic appearance.

162 G. Barber, I. Watt and J. Rogers

INT. J. OSTEOARCHAEOL., Vol. 7: 157±164 (1997) # 1997 by John Wiley & Sons, Ltd.

Figure 4. Grade 3. X-ray and photographic appearance.

Discussion and conclusions

Even if a conservative grade of `2' is taken asde®nite evidence for the presence of HFI, then atleast 31 per cent of females anthropologicallyaged over 45 have HFI. This is considerablyhigher than any archaeological prevalence pre-viously quoted. It con®rms the suspicion thatworkers reporting cases in archaeological mate-rial are not using the same criteria as the medicalprofession. These results show that no male inthis sample had a HFI grade of over 1,con®rming the modern literature stating thatmales are affected less commonly. More olderfemale individuals are affected than younger,which again concurs with the modern data.

It would seem that, comparing the directappearance of the sectioned skulls in Figures 2and 3 (Littlejohns' grades 1 and 2) theappearance of the HFI is much less ¯oridthan the usual pictures of the cases that appearin the archaeological literature.5 If only casesthat are grade 3 are counted, the prevalencebecomes much closer to the archaeologicalnorm, and it may be that only those mostextreme cases are recorded in palaeopatho-logical reports. Given these results the currentassumptions that the lack of HFI cases in thearchaeological literature are due solely to lowerlife expectancy surely must be challenged. If

researchers wish to use the presence of thisphenomenon as an indication of the age atdeath of a population the results of this papersuggests two actions. Firstly, when givinginformation on the percentage of the populationaffected, the number of skulls actually examinedinternally or X-rayed should be stated.Secondly, the grading method used on thesample should be stated (such as the directvisual method outlined in this text); if onlythose most ¯orid cases (grade 3) are noted, thisshould be clearly mentioned, and no furthercomparisons with percentages in modern popu-lations should be made.

Acknowledgements

The authors would like to thank Sadie Dunn for herhelp in this study, and the ®rst author would like toacknowledge the comments and provision of areference from Professor Desmond Hawkins, andvarious people who attended the AmericanAssociation for Physical Anthropology Meeting inNorth Carolina, April 1996. This work forms part ofan as yet unsubmitted PhD thesis by the ®rstauthor.

References

1. Salmi, A., Voutilainen, A. Holsti, L. and Unnerus,C. Hyperostosis cranii in a normal population.Radiology, 1962; 87(6): 1032±1040.

2. Gershon-Cohen, J., Schraer, H. and Blumberg N.Hyperostosis frontalis interna among the aged.American Journal of Roentgenology, Radiation Therapyand Nuclear Medicine, 1953; 73: 396±397.

3. Stroud, G. and Kemp, R. L. The Human Bones incemeteries of St Andrew Fishergate. York: C. B. A.Publications, 1993.

4. Henschen, F. Morgagni's Syndrome. London:Oliver and Boyd, 1949.

5. Farwell, D. E. and Molleson, T. I. Excavations atPoundbury 1966±80. Vol II: The Cemeteries.Dorset Natural History and Archaeology SocietyMonograph Series No. 11: The Friary Press Ltd.Dorchester, 1993.

6. Dayton, L. The fat hairy women of Pompeii. NewScientist, 1994; September 22.

7. Eldridge, W. and Holm, G. Incidence of hyper-ostosis frontalis interna in female patients admitted

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Table 2. Percentages of individuals with each grade ofhyperostosis frontalis interna (HFI) by sexÐall the sample.

HFI grade (per cent)

0 1 2 3

Male 70 30 0 0Female 50 31 14 5? sex 83 0 17 0

Table 3. Percentages of individuals with each grade ofhyperostosis frontalis interna (HFI) by sexÐthose over 45years only.

HFI grade (per cent)

0 1 2 3

Male (n=23) 83 17 0 0Female (n=13) 46 23 23 8

to a mental hospital. American journal ofRoentgenology and Radiation Therapy, 1940; 43(3):356±359.

8. Stewart, R. Localised cranial hyperostosis in theinsane. Journal of Neurology and Psychopathology,1927; 8: 321±331.

9. Moore, S. Hyperostosis frontalis interna. Surgery,Gynecology and Obstetrics, 1935, 61: 345±362.

10. Armelagos, G. J. Hyperostosis frontalis interna: aNubian case. American Journal of Physical Anthropology,1988; 76: 25±28.

11. Anderson, T. Unfair to beauties of old Pompeii?New Scientist, 1994; 26 September.

12. Phillips, S. M. Hyperostosis frontalis interna inthe 19th century Oneida burial sample. AmericanJournal of Physical Anthropology, 1996; Supplement22. Annual Meeting Issue.

13. Littlejohn, G. O., Hall, S., Brand, C. A. andDavidson, A. New bone formation in acrome-galy: pathogenetic implications for diffuseidiopathic skeletal hyperostosis. Clinical andExperimental Rheumatology, 1986; 4: 99±104.

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