Diagnosis of Pediatric CRPS

There is, unfortunately, no gold standard diagnostic test for CRPS in the pediatric population.

The diagnosis of CRPS-I is based on the history and the physical examination and rests on the Budapest criteria:

See Annexe 8: Budapest clinical diagnostic criteria for CRPS, p. 63.

The history must contain an assessment of the child’s familial, social, and academic environment, as well as a psychological evaluation. The physical examination usually reveals a normal neurologic examination, allodynia, and signs of autonomic dysfunction that might be present. The physical examination does not find anything suggesting an underlying disease as the cause of the patient’s complaints. It is crucial to eliminate any other possible causes as the differential diagnosis includes other neuropathic conditions and metabolic, systemic, vascular, and rheumatological disorders.

Therefore, even in cases with classic signs and symptoms, the initial inquiry usually includes blood tests and imaging (plain radiographs, magnetic resonance imaging, computed tomography, micro-CT and/or bone scintigraphy) of the affected limb. Baseline laboratory tests consist of a complete blood

Clinical features of complex regional pain syndrome in children and adolescents:

Pain descriptors → burning, painful numbness, shock-like, shooting, stabbing Neurovascular findings → coolness to touch, swelling, mottled appearance, other

color changes

Sudomotor changes → sweating, dryness, scaly patch of skin, shiny skin Motor disturbances → tremors, fasciculations, dystonia, spams, weakness Trophic changes → decreased, increased or unsual hair and nail groth patterns

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count, blood chemistry, C-reactive protein, erythrocytes sedimentation rate, creatinine kinase, antinuclear antibody, and rheumatoid factor. (16, 70, 155)

Differential diagnoses of CRPS-I:

Orthopedic disorders:

Fracture, bone contusion, sprain, bursitis, apophysitis, ligamentous injury, muscle injury.

Neurologic disorders:

Peripheral neuropathy, cervical/lumbosacral radiculopathy, neuroma, nerve entrapment, diabetic neuropathy, complex migraine, spinal cord trauma/tumor, transverse myelitis, syrinx, demyelinating disorders, poliomyelitis, Guillain-Barre syndrome.

Rheumatologic disorders:

Rhematoid arthritis, juvenile rheumatoid arthritis, osteoporosis, sarcoidosis.

Infectious disorders:

Systemic fungal/bacterial/viral infections, subacute or chronic osteomyelitis, Lyme disease.

Vascular disorders:

Vasculitis, arterial insufficiency, Raynaud’s disease.

Miscellaneous:

Toxic exposure to heavy metals (lead) or chemotherapeutic agents, porphyria, B12 deficiency, thiamine deficiency, Fabry disease, somatoform disorder.

Usually, CRPS-I patients have common laboratory values. Concerning the imagings, radiographic evidence of demineralization is often reported. Bone demineralization may be visible by radiograph or DXA Scan. Still, if the duration of the disease is lengthened or the degree of disability is consequent, bone demineralization due to disuse is extremely common. This bone loss, affecting the entire limb, is usually reversible within about six months. Computed tomography (CT) and, with even greater precision, micro-CT furnish quantitative measurements of bone morphology parameters. Bone scintigraphy has been helpful for a long time and used for the early diagnosis of pediatric CRPS-I where it reveals a decreased uptake in the affected area, producing a cold spot on the images. At a more advanced stage, when the clinical manifestations of pediatric CRPS-I decline, the differences between the two limbs tend to decrease or invert, with increased uptake in the affected limb. MRI abnormalities are far uncommon and aspecific and may reveal bone contusion or, edema.

39 5.7 Child psychiatry evaluation

As already outlined in this work, both psychological, family, social, environmental, and academic aspects are crucial in the care of children with CRPS.

A psychiatric evaluation in these children is essential to be able to evaluate individual, family, and child-parent functioning, and to exclude or highlight psychiatric comorbidities.

To do so, several specific areas of relevance to CRPS management should be addressed in the psychological evaluation, including:

- presence of comorbid Axis I psychiatric disorders - cognitive, behavioral, and emotional responses to CRPS - ongoing life stressors

- responses by significant others to the patient’s CRPS

Axis I psychiatric disorders such as Major Depression, Panic Disorder, Generalized Anxiety Disorder, and Posttraumatic Stress Disorder are at least as prevalent in CRPS patients as in other chronic pain patients.

As highlighted, a depression, when diagnosed, can be a significant barrier to success in active

physically focused treatment modalities (e.g., Physical Therapy (PT) and Occupational Therapy (OT)) due to also diminished energy level and low or lack of motivation and therefore should be assessed. So is anxiety in the light of the fear avoidance model as described.

Identification of specific life stressors and general emotional arousal (low mood, anxiety, fear, anger), even in the absence of a clinically diagnosable psychiatric disorder, is also important given the psychophysiological interactions hypothesized above. The psychological evaluation must assess the patient’s pain as well, although with a somewhat different emphasis than in the medical

evaluation.(24, 55)

The assessment of pain should evaluate how the pain relates to the functioning and the patient’s cognitive and emotional state. Although some activity avoidance may seem reasonable and directly connect to pain, other activity avoidance may be extreme and unreasonable. For example, several CRPS patients displayed extreme social avoidance, including reduced contact with family members, which can be mistaken for agoraphobia but is only a way for the patients to avoid being accidentally bumped in their allodynic extremity by those around them for example. (24)

A few studies that incorporate psychiatric clinical interviews have been published involving larger samples of children with CRPS and concluded that children and adolescents with CRPS had a high

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prevalence of elevated emotional distress compared with healthy peers and tended to be high achievers living in high-stress families. (5, 67, 79, 85, 126, 135, 161)

Sherry and Weisman studied psychosocial factors in 21 families of children with CRPS. They identified two different types of families, the first with a high level of cohesion, expression, and organization and with a low to average level of conflict (n=15), and the second (n=6) with a high overt conflict level and a low level of family cohesion, expressiveness, and organization. They reported that in all cases, there was significant parental enmeshment with the patient. Although most of the children were described as particularly bright, only 4 of them had above-average intelligence test scores. They also reported that multiple different stressors were present in these children, including marital conflict between the parents (n=12), significant school problems (n=13) and sexual abuse (n=4). (122)

Sherry et al. in another study on clinical and psychological findings on 100 children with

psychosomatic musculoskeletal pain, found that almost all the children maintained a cheerful affect when complaining of severe pain. Although frequently viewed as bright, most of these children had average intelligence, and some had unrecognized academic difficulty. In this study, the authors had the impression that the pain symptoms worked to relieve stress by focusing attention on the patient, reducing expectations of achievement or interrupting family conflict and the children were not expected to continue to perform academically or socially while in pain. Regarding the family setting, two predominant abnormal family milieus were also described: one was cohesive, stable, and organized but intolerant of separation and individuation and the other was chaotic, emotionally unsupportive, with high levels of conflict. Enmeshment between mother and child was also common in this study in both family types. (123)

Stanton et al. in reviewing a series of patients with CRPS, noted that 83% of the patient's given psychological evaluations had ‘‘significant emotional dysfunctions.’’ This was not further defined, although a great deal of stress in the lives of the patients was also reported. (135)

Vieyra et al. performed a preliminary study comparing patients with CRPS (n=28) to children with migraine headaches (n=21) and 21 healthy controls. Children with CRPS reported experiencing more painful days, higher pain severity with shorter chronicity, and more caretaking by their parents.

Contrary to expectations, no differences in family functioning were found among the three groups.

(149)

Cruz et al. in a study with 17 children and adolescents (all female; ages 9 to 18 years) diagnosed with CRPS1, reported consistent evidence for somatization. The patients had neuropsychological

assessments that included emotional functioning questionnaires, projective personality measures, and

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neuropsychological measures. 38% of patients exhibited at-risk/elevated mood symptoms (anxiety or depression) based on self-report or parent report. A substantial proportion of patients (36%), however, showed a high risk of difficulties with attention/working memory. (29)

Jaworowski et al. reported CRPS in a 12-year-old girl who developed a conversion disorder simultaneously; her identical twin also had a conversion disorder. (65)

A case series by Brommel et al. (n=22) based on a psychanalytic interview found psychological dysfunction in children with CRPS and they concluded that the dispair of these patients about their reflex sympathetic dystrophy expressed unsolved fears of early childhood. (20)

Children with Complex Regional Pain Syndrome Type 1 may experience emotional distress that can also be identified by using multiple assessment methods and questionnaires.

To mention some questionnaires used in the literature regarding CRPS, besides the questionnaires already cited in chapter 5 (Pain-related fear concept), we must cite :

Questionnaires:

- Functional impact by the Functional Disability Inventory (FDI)

- Social impact through school absenteeism and the Adolescent Perceived Life and Health -Scale (VSP-A12)

- Emotional impact by the Strengths and Difficulties Questionnaire (SDQ) - Anxiety Scales for Pupils

- Child Depression Inventory

- The Pain Response Inventory (PRI)

Catastrophic cognitions (e.g., patients may believe that CRPS is an untreatable, progressively deteriorating condition that will necessarily spread throughout the body), incorrect beliefs regarding the meaning of CRPS pain and mistaken beliefs regarding how CRPS treatment should progress (e.g.

common misconceptions beliefs that sympathetic blocks alone are curative, and that treatments that exacerbate pain temporarily cannot be valuable) are often a contributor to negative emotional states that can have a negative impact on CRPS and responses to treatment. (24)

However, the psychiatric evaluation should also include personal and family history and should look for some traits described in the clinic with these children as:

lack of self-confidence, abandonment/separation anxiety, meticulous, opposition, intolerance to frustration, lack of framework, parental couple conflict on education, feeling of unfairness, the feeling that we ask too much of them, the idea that the patient decides when to heal and the fear of not being taken seriously/understood/mad.

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Sleep disturbances for disturbed or interrupted sleep commonly occur in children with CRPS, and the majority will complain of difficulty getting to sleep and frequent awakenings. (10)