Diagnosis and Recording of Pathologies

The diagnosis of pathology within past populations relies on the observation of abnormal changes of the skeleton. Therefore, it is not possible to identify those disease processes that leave no osteological trace, resulting in the underestimation of the true pattern of disease within the past (Waldron 2007: 59ff). The pathological changes observed in the skeleton are the result of two processes: bone formation or bone destruction, or a combination of the two (Ortner 2012: 252). The first and most important stage in palaeopathological diagnosis is the careful macroscopic examination and accurate description of all pathological lesions present (Lovell 2000: Table 8.1 for recommended terminology). Radiography, histology, or biochemical techniques may also be utilised to ascertain additional information (Donoghue 2008; Mays 2008a; Turner-Walker and Mays 2008). The identification of the bone processes present (i.e. bone formation/destruction/both) and the type and location of a lesion will provide evidence regarding the nature of the pathology and the individual’s stage of healing (Roberts and Manchester 2005: 8). For example, rapidly deposited woven bone occurs during the active stage of lesion formation, while smooth compact lamellar bone is indicative of healed or chronic, long-standing conditions (Grauer 2008: 62). Following this, it is essential to determine the location of the lesion(s) and their skeletal distribution.

From this information it should then be possible to assign pathological changes to a particular disease classification – e.g. trauma, metabolic disease, infectious disease, etc (Lovell 2000: 219; Ortner 2012: 262). Utilising knowledge gleaned from clinical and palaeopathological literature, it may be possible to be more specific regarding the type of disease process (important palaeopathological texts include amongst others: Aufderheide and Rodríguez- Martín 1998; Ortner 2003; Roberts and Manchester 2005; Pinhasi and Mays 2008; Waldron 2009; Grauer 2012; Larsen 2015). For example, particular features of a lesion, or the nature of the lesion distribution observed within a skeleton may be indicative, or pathognomonic, of a specific disease (e.g. Roberts and Buikstra 2003; Brickley and Ives 2008). For example, eburnation is considered to be pathognomonic of osteoarthritis (Waldron 2009: 28), while rhinomaxillary syndrome is considered pathognomonic of lepromatous leprosy (Andersen and Manchester 1992: 122). However, due to the limited capability of bone to react to pathological stimuli, similar lesions may be observed for a number of different diseases (Roberts and Manchester 2005: 9). For example, periosteal new bone formation is associated with a number of different infectious diseases, such as leprosy and syphilis, as well as trauma, and neoplastic disease (Weston 2008: 49-50). Therefore, the differential diagnosis of all likely disease processes implicated in the production of a pathological change is necessary. The age of an

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individual should also be considered when interpreting pathological changes, as differences in the type and distribution of lesions caused by the same disease process may be observed in subadults and adults (Lewis 2007: 133ff). For example, due to age-related differences in bone vascularity, haematogenous osteomyelitis in subadults is most commonly found within the metaphyseal region of long bones, whereas in adults the vertebrae are more often affected (Rosenberg et al. 2010: 341-344). Differential diagnosis may not always allow further specificity beyond a disease classification, and it is important to avoid over-diagnosis in the absence of sufficient evidence (Ortner 2012: 252).

The skeletal pathologies utilised in this analysis are taken from the WORD database. The WORD recording methodology and diagnostic criteria for each indicator used in this research are described below (Powers 2007, and Powers 2012a). All osteological examinations were undertaken by professional osteologists following the step-by-step procedure of diagnosis recommended by Roberts and Connell (2004). All lesions were examined macroscopically and, where appropriate, radiographs of skeletal elements were taken to ascertain definitive

diagnoses. In this study, in order to ensure consistency in the data collection, pathologies were only recorded as present if they had been positively diagnosed recorded on WORD in the appropriate disease categories. For example, for an individual to be recorded as having tuberculosis, it must have been recorded specifically under the disease code for tuberculosis (i.e. 221).

As discussed in chapter 2, Goodman et al. (1988) advocate the assessment of multiple skeletal indicators of both chronic and acute stress in order to evaluate the adaptation of a population to environmental and cultural stressors. In addition, they demonstrated that the use of this methodology allows for the identification of the members of a community that are most affected. The stress indicators utilised for this analysis include: cribra orbitalia, porotic hyperostosis, enamel hypoplastic defects, and non-specific infection (periostitis and maxillary sinusitis). These stress indicators were selected as they are the most commonly studied stress markers in subadult populations and they were consistently recorded in WORD. As the

radiography of long bones was not consistently undertaken, the presence of Harris Lines could not be assessed. The fragmentary nature of the skeletal collections meant that many of the subadult remains could not be used for the metrical analysis of growth, and this stress marker was also excluded from the study. Other potential stress markers identified by Goodman et al. (1988) were excluded due to their absence in the sample (i.e. trauma), or a lack of available data (i.e. vertebral canal stenosis, skull base height). Due to the primary focus on subadult individuals, those stress indicators recorded solely in adults, such as a lack of sexual dimorphism and adult stature, were also not included. In addition to the aforementioned

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stress markers, two metabolic diseases indicative of nutritional deficiency were also included in the analysis, namely vitamin D deficiency (rickets and osteomalacia) and vitamin C

deficiency (scurvy). These deficiency diseases are considered with the stress indicators in this study to identify overall levels of stress within the sample population.

The occurrence of each of the studied pathologies within the sample is either given as a:  Crude prevalence rate (CPR) - the percentage of individuals within the sample

affected as a percentage of the total population, or

 True prevalence rate (TPR) - the percentage of individual elements affected as a percentage of the total number of elements available for analysis. The type of data presented for each of the pathologies is given in the following sections.

(i) Cribra orbitalia

In WORD, the presence and absence of the left and right orbits are recorded for each individual (Mikulski 2012: 52). If an orbit is not present, it is coded as unobservable (code 9). Each orbital roof present is examined macroscopically and lesions are recorded as present or absent, following the grading system by Stuart-Macadam (1991: 109) (see Table 5.9) (Mikulski 2012: 52).

For this study, the presence and absence of the orbital roofs of each individual was recorded. An individual had to have at least one orbital roof present in order to be included in the prevalence rate calculations for the sample. Those individuals with no orbital roofs were excluded. In the remaining individuals, cribra orbitalia was recorded as present if at least one of the orbital roofs was affected. The prevalence of cribra orbitalia in the sample is presented as a CPR, giving the number of individuals affected as a percentage of the total number of individuals with at least one orbit present.

Following this, the cribra orbitalia score assigned to each orbit was recorded (Table 5.9). Where right and left orbits had different degrees of expression, the larger score was used for analysis by lesion score.

128 Code Description

0 Normal Bone Surface

1 Capillary like impressions on the bone 2 Scattered foramina

3 Large and small isolated foramina

4 Foramina have linked into a trabecular structure

5 Outgrowth in trabecular form from the outer table surface 9 Not present/unobservable

Table 5.9: Pathological codes for the description of cribra orbitalia (after Stuart-Macadam 1991: 109)

(ii) Porotic Hyperostosis

Porotic hyperostosis is recorded in WORD by presence or absence in the miscellaneous blood disorder category, under the code 1010, with descriptions given of the lesion and its

distribution (Powers 2007:26). The diagnostic criteria followed is that of Stuart-Macadam (1987).

In this study, porotic hyperostosis is recorded at the individual level as present or absent. Porotic hyperostosis was only recorded as present when it was specifically diagnosed, under the pathology code 1010. In order to calculate prevalence rates, individuals were included within counts if one or more of the bones of the cranial vault (namely the frontal, parietal, squamous temporal or squamous occipital bones) were available for macroscopic inspection. Therefore, the prevalence of porotic hyperostosis in the sample is presented as a CPR, giving the number of individuals affected as a percentage of the total number of individuals with at least one bone of the cranial vault present.

(iii) Enamel Hypoplasia

The diagnosis of enamel hypoplasia in WORD is based on criteria obtained from Hillson (1996: 167) (Kausmally 2012: 24). Each individual tooth is examined and the presence of any enamel hypoplastic defect is scored by severity and location (Table 5.10). If more than one defect is present on an individual tooth, the location recorded was that of the most severe defect (Powers 2007: 17).

In this study, enamel hypoplasia is recorded at the individual level as present or absent, with individuals exhibiting one or more defects being recorded as affected. If an individual had no teeth present, they were recorded as unobservable and removed from prevalence rate

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calculations. Therefore, the presence of enamel hypoplasia in the sample is presented as a CPR, giving the number of individuals affected as a percentage of the total number of individuals with at least one tooth present. As no measurements from the cemento-enamel junction were available, it was not possible to determine the age at which the person developed the defect.

Enamel Hypoplastic Defect Grading System Location Of Enamel Hypoplastic

Defect

Severity of Enamel Hypoplastic Defect

Code Location of Defect Code Severity of Hypoplastic Defect

Definition

1 Cusp/Upper Crown 1 Linear Enamel Hypoplasia –

Just discernible

Can be seen but not felt with fingernail

2 Middle Crown 2 Linear Enamel Hypoplasia –

Clear groove on tooth surface

Clearly felt with the fingernail

3 Lower Crown 3 Linear Enamel Hypoplasia –

Gross Defect (Ridges/dentine exposed)

Clear brown ridges on enamel surface

4 Hypoplastic Pit Circular Defect on

Crown Table 5.10: Grading system for enamel hypoplastic defects (taken from Powers 2007: 17)

(iv) Non-Specific Infection

On the WORD database, infectious diseases are recorded according to the involvement of the bone, i.e. periosteal involvement, osteitis, and non-specific osteomyelitis. The WORD

diagnostic criteria for each of these are as follows:

 Periosteal involvement is diagnosed when the presence of either abnormal

pitting/porosity of the bone surface or periosteal new bone formation overlying the original bone surface is observed. (Powers 2012c: 37).

 Osteitis is diagnosed when a swelling or expansion of the original bone surface is observed without the presence of a cloaca (Powers 2012c: 38).

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 Osteomyelitis is diagnosed when a swelling or expansion of the original bone surface is observed alongside an involvement of the medullary cavity in the form of a cloaca (Powers 2012c: 38). Other indicative elements include the presence of a sequestrum and involucrum (Powers 2012c: 38).

Following the identification of a lesion, descriptions of the location are recorded, including: the type of new bone (woven, striated, lamellar, spiculated, etc.) and a classification of healed or active at time of death is given following the guidelines of Roberts and Connell (2004: 35). Analysis of the type of lesions and their distribution are conducted to determine the potential infectious process and, if possible, the specific infection (see Section 5.2.3 (v)). If a specific infection is identified, the lesions observed will be coded to that particular pathology (e.g. tuberculosis is 221). Where a specific infection cannot be identified, the lesion is recorded as non-specific infection (i.e. 211 for periostitis, 214 for osteitis, and 213 for osteomyelitis). For this study, the presence of non-specific infection (i.e. periostitis, osteitis, and osteomyelitis that cannot be attributed to a specific infection) was recorded for each individual. The location of each lesion was recorded by element, along with the available description included on WORD. Only individuals that were specifically recorded as having evidence of non-specific infection on WORD were identified as having non-specific infection present. Furthermore, as they have multiple aetiologies (Weston 2012), all periosteal lesions that could be attributed to another diagnosed pathology, such as trauma or metabolic disease, were removed from prevalence counts.

For analytical purposes, non-specific infection is first considered at the individual level to ascertain general levels of non-specific infection within the population, giving a CPR of the number of individuals affected as a percentage of the total population. Unfortunately, the descriptions of lesions given in WORD varied and detailed information was not consistently recorded. Therefore, the prevalence of lesion type can only be given at the level of bone affected (i.e. periosteal involvement, osteitis, or osteomyelitis). The available description of each lesion given on WORD is recorded in Appendix 6. As CPR’s are affected by preservation, TPR’s for individual bones are also presented, i.e. the number of individual elements affected as a percentage of the total number of observable elements. Laterality of the lesions was also recorded.

As it was not possible to ascertain the extent to which sinus cavities were studied within the sample, sinusitis was excluded from overall non-specific infection counts and presented as a separate category. Sinusitis was diagnosed if new reactive bone was observed within any of the sinus cavities, most notably those of the maxillary and frontal bones (Powers 2012c: 39).

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As it was not possible to identify the number of individuals with exposed sinuses (i.e. broken post-mortem, thus enabling direct observation) that could be examined, TPR could not be calculated.

(v) Specific Infectious Disease

Where assessment of the type and distribution of pathological lesions allows the identification of a specific disease, the lesions are assigned to a specific disease code. As with non-specific infection, all elements affected were recorded, alongside the type (i.e. destructive or proliferative) and severity of bony changes (periosteal new bone formation, osteitis, and/or osteomyelitis) following the guidelines of Roberts and Connell (2004: 34-37) (Powers 2012c: 38). In order for a diagnosis of a specific infection to be recorded on WORD, disease specific diagnostic criteria had to be satisfied. For example, tuberculosis is diagnosed macroscopically using the diagnostic criteria of Rogers and Waldron (1989), Resnick and Niwayama (1995); Aufderheide and Rodríguez-Martín (1998: 133-140); and Ortner (2003: 227-262) (Powers 2012c: 38-39). For subadults, further information is obtained from Lewis (2011).

In this study, the presence of a specific infection was only recorded when it was positively diagnosed and coded in WORD. Prevalence rates for specific infection are given as CPR’s, i.e. the number of individuals affected as a percentage of the total number of individuals within the sample.

(vi) Metabolic Diseases

The WORD diagnostic criteria for the metabolic diseases considered in this study follow the criteria and guidelines described in Ortner (2003: 383-418) and Aufderheide and Rodríguez- Martín (1998: 305-344) (Mikulski 2012: 51). Further guidelines considered for specific diseases are given below. In this study, metabolic diseases are identified as present or absent at the individual level as CPRs. The metabolic diseases were only considered as present if they had been diagnosed as that metabolic condition in the database, or the original osteologists identified it as the most likely diagnosis.

(a) Vitamin D Deficiency - Rickets

In WORD, rickets is diagnosed based on the criteria of Mays et al. (2006) and Ortner and Mays (1998) (Mikulski 2012: 51). The subadult remains were also re-examined by Dr. Rebecca

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Redfern in 2012 using the methods published by Brickley and Ives (2008). All infant cases were also digitally radiographed to aid diagnosis.

Diagnostic changes include:  Bowing of the long bones

 Lack of cortical density towards the metaphyses

 Thickening of the cranium by sub-periosteal new bone deposition  Flaring and cupping of metaphyseal ends

 Decreased curvature of the ribs

 Rachitic rosary characterised by enlarged or flared sternal rib ends

(b) Vitamin D Deficiency - Osteomalacia

Osteomalacia was diagnosed following the guidelines of Brickley et al. (2007) (Mikulski 2012: 51-52). Diagnostic criteria included:

 Healed and unhealed fractures at or around the base of the acromial spine (considered the most diagnostic)

 Vertebral collapse

 Angular “kinking” of the sacrum  Stress fractures

 Accentuated cupping of vertebral end plates leading to angular kyphosis in severe cases, usually at the level of T8-9

 Decreased curvature in the ribs  Angular deformation to the sternum

 Abnormal morphology of the pelvic girdle – severe reduction of sub-pubic angle and narrowing of the pelvic canal

(c) Vitamin C Deficiency - Infantile Scurvy

Infantile scurvy is considered following the diagnostic criteria of Brickley and Ives (2006) (Mikulski 2012: 52). As with vitamin D deficiency, subadult human remains were re-examined by Dr. Rebecca Redfern in 2012 using the methods published by Brickley and Ives (2008). All infant cases were also digitally radiographed to aid diagnosis.

133 Diagnostic changes include:

 Profuse irregular porous new bone plaques on ectocranial surfaces (with “honeycomb” appearance), pitting to the lingual aspects of the mandibular rami, and new bone on the diaphyses of long bones (in particular the humerii, femora, tibiae, and fibulae)  New bone formation in the orbits

 Flaring of sternal rib ends – “scorbutic” rosary

 Porosity or porous new bone formation on the muscle attachment sites, such as the suprascapular fossae.

(d) Vitamin C Deficiency - Scurvy in Adults

Scurvy in adults was considered following the diagnostic criteria of Aufderheide and Rodríguez- Martín (1998: 313) (Mikulski 2012: 52). Diagnostic criteria included:

 Symmetrical periosteal lesions with a shell of lamellar bone attached to the original cortex via woven bone

 Evidence of haematoma  Pathological fractures

 Gingival haemorrhage leading to tooth loss  Orbital lesions (new bone formation)

In document Childhood Health and Diet in Roman London: The Palaeodemographic, Palaeopathological and Isotopic Evidence (Page 150-158)