OSTEOPOROSIS IN ADULTS WITH CEREBRAL PALSY

Christina Marciniak, Joelle Gabet, JungWha Lee and Nicole WyosckiThe Rehabilitation Institute of Chicago and Northwestern University

AAPMR November 2014

NO AUTHORS HAVE ANY RELEVANT DISCLOSURES

Disclosures

BACKGROUND: CHILDREN WITH CPAND BONE MINERAL DENSITY Low bone mineral density (BMD) has consistently been

shown for children with cerebral palsy compared to non-disabled, and differences are increased as children age.

(Henderson, 2005)

• Predictors of BMD: Level of ambulation Nutritional status Body mass index (Henderson,2004)

Distal femur site reference values and techniques have been developed.

Longitudinal studies of children with CP and subsequent rate of change of BMD in adulthood have not been reported.

Studies in children with osteoporosis have shown response to bisphosphonates, but long term safety is unknown.

IN CHILDREN WITH CP, FRACTURES HAVE BEEN REPORTED IN 16-26%

Axial – 4%Upper Limb – 14%

Femur 48%

Tibia – 27%

Foot – 7%

Presedo, J Pediatr Orthop. 2007

Sixty-six percent of patients had spastic quadriplegia, of whom 83% were nonambulatory.

Risk Factors:anticonvulsant therapy spastic quadriplegia nonambulatory, osteopenic

DUAL ENERGY X-RAY ABSORPTIOMETRY

BMD = grams/centimeter squared• Relative Risk of hip fracture increases by 2.5 for every SD decrease

in femoral neck BMD. T score = SD more or less than a young adult with same sex

• Osteopenia = T score between -2.5 to -1 • Osteoporosis is less than or equal to -2.5 (expert consensus)• Recommendations based on T scores and fracture risk (FRAX)

T VS. Z SCORES

Z Score = Number of standard deviations more or less than a same age reference mean• Z scores are used in adults less than 50• Treatment recommendations have been based on

Z:- 2.0 and significant fracture

BACKGROUND: ADULTS WITH CP AND BMD

King (2003) L-spine 48 non-ambulatory children/ adults- Ages 5 - 48years (19 adults)

- Average z =2.37

- 58% had z scores lower than expected.

Yoon (2012) : 38 adults (mean age 35 years) Only 6 subjects with spastic quadriplegia, 12 non-ambulatory.• Average T score L spine -1.08 and Hip -1.5 (No Z scores reported)• BMD was not associated with gender, age and subtype of CP.• BMI correlated with BMD of L spine and femur• No difference in L spine for walker vs. non-walker• Higher ambulatory function positively correlated with BMD of

femur.

CURRENT SCREENING RECOMMENDATIONS

National Osteoporosis Foundation:• Woman 65 and old and men 70 and older• Younger peri-menopausal and men 50-69 with risk factors• Adults with fracture after age 50• Adults with medical condition or medication associated with low bone

mass or bone loss

Do NOT list CP under neurological conditions with risk for osteoporosis, though do list impaired transfers and mobility

Canadian Guidelines:• Women and men 65 years and older• Women and men 50-64 with risk factors• Younger men or women (under 50) with a disease or condition

associated with low bone mass or bone loss/ Fragility fractures

CHANGES IN BMD WITH AGE

• Adults with CP lose function at an earlier age.

OUR STUDY

Objective: • To identify factors associated with low bone mineral density

(BMD) in adults with cerebral palsy (CP) • To assess for longitudinal BMD changes 

Design: Retrospective review study

Participants: Adults with CP seen in an adult physiatry clinic over a two 1/2-year period and who had at least one dual-energy X-Ray absorptiometry (DXA) scan to assess bone health status over a 7 year time frame

HYPOTHESIS: OSTEOPOROSIS IN INDIVIDUALS WITH CP

• Low bone mineral density will be seen with high frequency in adults with CP.

• Z scores will decrease with age• Lower mobility levels will correlate with

lower BMD at hip sites, but not L spine locations.

MEASURES: Bone Mineral Density

Baseline and change

3 sites: L spine, total hip and femoral neck

T scores

Z scores Demographic

• Age• Sex

Body Mass index Gross Motor Function Classification Scale (I-V) Level of ambulation (none vs exercise or

community) /transfers CP Type: pattern (e.g. hemi- vs. quadriplegia)

and tone (spastic, dystonic, ataxic or mixed)

RESULTS

97 adults seen in time frame• 5 patients unable to obtain due movement disorder/cognitive• 3 declined• 18 had DXA at other facility• Others GMFCS I – III or Dxa performed outside of time frame

42 had at least one DXA performed at our institution.17 had two DEXAs performed

2 had had interventions following initial study, leaving 15 for analysis

Of the 42, 83% were less than age 50 years

RESULTS: DEMOGRAPHICSAge at first DEXA, years M (range) 38.9 (22.4-73)

<50 (n=35) , years M 34.2 years

50 or greater (n=7) , years M 62.2 years

Sex, N (%) Male/Female 24 (57.1) / 18 (42.9)

Anthropometrics

Weight, (kg) M (±SD) 59.4 (19)

BMI, (kg/m2) M(±SD) 59.4 (19)

Median (Range) 23.2 (14.2-39.9)

Under Weight 8 (19.05)

Normal weight 20 (47.6)

Overweight 7 (16.7)

Obese 7 (16.7)

Race, N (%)

Caucasian 29 (69.1)

African American 12 (28.6)

Asian 1 (2.4)

M = meanN = number

RESULTS: FUNCTIONAL AND MEDICAL

GMFCS Level

16.67

52.38

30.95

II-III

IV

V

PATTERN

4.76

19.05

2.38

73.81

HemiplegiaDiplegiaTriplegiaQuadriplegia

RESULTS: OSTEOPOROSIS AND FRACTURES

Osteoporosis/Osteopenia by T score criteria: ALL subjects had at least

one site with osteoporosis/osteopenia in LE• Osteopenia – 14 (33%)• Osteoporosis – 27 (64%)

Fractures Seven patients (16.7 %)

with fractures 12 fractures (5 with 2

fractures) • Foot/Toes: 4• Femur – 1• Tibia/fibula – 3• Spine – 3• Rib – 1

Lower BMD at the spine, left and right total hip, and right femoral neck sites was associated with quadriplegia.

Lower BMD at the left total hip and right and left femoral neck sites was associated with needing assistance with transfers and no ambulation.

RESULTS: MEAN T AND Z SCORES

Note: DXA could not be performed at all sites to due prior procedures/positioning/contractures.

Site Number of studies(All/<50)

T score Z- score Z-score <50 yr(range)

Lumbar Spine 38/32 -1.98 -1.69 -1.82

Total Hip R 27/27 -1.94 -1.60 -1.88

Total Hip L 34/27 -1.80 -1.50 -1.53

Femoral Neck R

33/27 -2.38 -1.94 -2.05

Femoral Neck L

35/29 -2.02 -1.56 -1.66

SPINE T SCORES BY AGE VS GMFCS

No relationship between osteoporosis presence and GMFCS P = 1.0Note: incidence low

SPINE Z- SCORES BY AGE AND GMFCS

LEFT FEMORAL NECK T SCORES

Higher GMFCS level is associated with osteoporosis at left femoral neck (p= 0.021).

LEFT FEMORAL NECK Z SCORE VS AGE AND GMFCS

LEFT TOTAL HIP T SCORES

Osteoporosis at the L total hip site was not associated with GMFCS (P=.449)

LEFT TOTAL HIP Z SCORE VS AGE

T SCORES SPINE FIRST TO NEXT DEXA

Percent change per year mean = - 4% per year

Z SCORES (SPINE) FROM 1ST TO NEXT DXA

Percent change per year -10%

LEFT TOTAL HIP T SCORE FROM FIRST TO NEXT DEXA

Percent change per year -5%

LEFT TOTAL HIP Z SCORE DEXA 1 TO 2

Left total hip z score change per year -6%

LIMITATIONS

Limitations - largely non-ambulatory population Not always easy to obtain BMD in this population

• Positioning/Contractures• Prior surgeries (hip and spine)• Movement disorders/cognition• Best location to identify who is at risk has not been identified.

CONCLUSIONS

Lower than expected-for-age BMD was found to be very frequent in adults with CP with mobility limitations

Low BMD is present at both lumbar spine and hip sites. Quadriplegia, transfer assistance and no ambulation is

associated with the presence of osteoporosis, at multiple sites

GMFCS did not correlate with spinal osteoporosis

THANK YOU!