Vol 43 # 3 September 2011 - Kma.org.kw

September 2011
urea 4.3 mmol/l, creatinine 55 Umol/l, serum sodium
141 mmol/l, potassium 4.1 mmol/l, bicarbonate
24 mmol/l, calcium 2.49 mmol/l, albumin 40 g/l,
alkaline phosphatase 159 IU/l. ferritin 185 ng/ml.
Renal function and electrolytes were normal. C-reactive
protein 3 mg/l, ASO-titer < 20 Todd units, rheumatoid
factor < 20 IU/l, CK 141 IU/l, LDH 191 IU/l. Blood,
urine and throat cultures showed no growth.
Doppler ultrasound of right lower limb (done
twice) showed no evidence of deep vein thrombosis.
Magnetic resonance imaging (MRI) of the hip showed
that the posterior column of the right acetabulum
including the ischial bone had low signal intensity on
T1-weighted images, with a thin rim of high signal
intensity seen in the soft tissue medial to the right
acetabulum with significant enhancement of this
abnormal signal intensity. Minimal right-sided joint
effusion was seen. There was normal joint congruity
with no evidence of slipped capital femoral epiphysis.
In addition, a CT study was performed that showed no
lytic or sclerotic lesions and no cortical destruction. An
MRI of the lumbosacral spine showed that the lumbar
intervertebral disks were normal in signal intensity.
There were minor disk bulges seen from L3-4 to L5-S1.
These were touching the thecal sac but not affecting
the nerves. There was minimal bilateral narrowing of
the lower part of the neural foramen at L4-5. The other
inter-vertebral disks and the canal and foraminae at
these levels were all within normal limits.
A neurosurgical specialist evaluated the patient and
he was of the opinion that the radiological findings did
not correlate with the clinical picture and ruled out any
neurosurgical problems. This led to us to perform a
bone scan that showed hyperemia of the right hip joint
region during the flow and blood pool. The delayed
whole body and static images showed increased tracer
uptake of the right hip joint, right ischium, trochanteric
region, knee joint, ankle joint and the right foot. The rest
of the skeleton was unremarkable. This bone scan led
to the diagnosis of right lower limb reflex sympathetic
dystrophy.
S.A. remained in hospital for five weeks with
restricted movement and refusing physiotherapy due
to pain. She started receiving transcutaneous nerve
stimulator treatment and seemed to be satisfied. A
pediatric rheumatologist saw the patient and his
opinion was consistent with the diagnosis of CRPS.
He advised to start physiotherapy, naproxen, an oral
non-steroidal anti-inflammatory drug (NSAID), and
ranitidine. The patient did not show any improvement
after four weeks of NSAID and it was stopped.
Carbamazepine was started by 5 mg/kg and gradually
was built up to 10 mg/kg. She started to sleep better
and her pain improved slightly. The pain service offered
our patient a spinal block but her mother refused all
other modalities of treatment since they were traveling
to the UK for further management.
KUWAIT MEDICAL JOURNAL 245
DISCUSSION
CRPS is defined as chronic musculoskeletal pain
dysfunction. In children, there is a female to male
predilection, and 80% of cases involve the lower
extremity [2-4] . According to the International Association
for the Study of Pain, the characteristic features
required to establish its diagnosis are as follows: (1)
the presence of an initiating noxious event or a cause
of immobilization; (2) continuing pain, allodynia, or
hyperalgesia with pain disproportionate to any inciting
event; (3) evidence at some time of edema, changes in
skin blood flow, or abnormal sudomotor activity in
the region of the pain; and (4) the exclusion of medical
conditions that would otherwise account for the degree
of pain and dysfunction [4,5] . Our patient fulfilled the
above criteria. We excluded other conditions that might
cause pain and dysfunction like osteomyelitis, deep
venous thrombosis, orthopedic or other neurosurgical
conditions. Her normal inflammatory markers
(including ESR, CRP, WBC, platelets, and rheumatoid
factor) and the clinical picture excluded connective
tissue disorders.
The onset of CRPS is usually linked to a history
of trauma, immobilization, or surgery. There is no
correlation between the severity of the initial injury
and the ensuing painful syndrome [4] . The pain in our
patient started two weeks after a minor trauma and was
disproportionate to the inciting event. Psychological
factors, such as stressful life events and inadequate
coping mechanisms, are potential risk factors that
influence the severity of symptoms in CRPS [4] . This
may have been a risk factor in our patient due to her
family’s poor psychosocial situation.
The clinical presentation consists of a triad of sensory,
autonomic, and motor signs and symptoms [3,5,6] . Pain
in CRPS varies in quality from a deep ache to a sharp
stinging or burning sensation. Often, patients report
that the pain is worsened by environmental (cold,
humidity) and emotional (anxiety, stress) factors.
Cutaneous hypersensitivity presents as pain on
contact with clothing or exposure to a cool breeze. The
involved extremity is often guarded, even from the
examining physician. Patients frequently experience
pain from tactile stimuli (allodynia) and have an
increased response to painful stimuli (hyperalgesia) [4] .
The pain that was described in our patient was
burning in nature, worsened by cold and improved
with hot baths. She experienced pain even in contact
with clothing or with light touch.
MRI is often normal or shows non-specific soft
tissue changes [7] (e.g., periarticular marrow edema often
involving more than one bone, soft tissue swelling,
joint effusions [8] and a subchondral band of low T1-
weighted intensity). The MRI of our patient showed
low signal intensity on T1-weighted images involving
the acetabulum and the ischial bone with minimal
joint effusion. The three-phase bone scan plays an