Keywords
charcot arthropathy - neurogenic arthropathy - syringomyelia - shoulder
Palavras-chave
artropatia de charcot - artropatia neurogênica - siringomielia - ombro
Introduction
Charcot arthropathy is a chronic, normally progressive, degenerative disease caused
by a sensorineural deficit that causes destruction of one or more joints.[1] Early diagnosis of Charcot neuroarthropathy is essential to prevent disease progression.
Feet and ankle involvement are more prevalent in diabetics. The knee is most often
affected in patients with syphilis. In syringomyelia, the shoulder and elbow joints
are most commonly affected.[2] Syringomyelia is a chronic, progressive, and degenerative disorder of the spinal
cord with formation and enlargement of a central fluid cavity (syrinx), affecting
pain and thermal sensations, and generally sparing motor function and proprioception.[3] The etiology of the disease can be congenital, Arnold-Chiari malformation type I,
communicating hydrocephalus, trauma, spinal tumors, infection, degeneration, or vascular
disease.[4]
About 5% of Charcot arthropathy cases affect the shoulder joint.[5] Shoulder involvement in Charcot neuroarthropathy is commonly misdiagnosed and often
confused with infections, rotator cuff tendon rupture, fractures, or pathological
conditions with a better prognosis.[6] The most common cause of shoulder Charcot arthropathy is syringomyelia. A quarter
of patients with syringomyelia develop neuropathic arthropathy.[7] In general, joint symptoms may appear earlier than neurological symptoms. Charcot
arthropathy can develop insidiously as well as abruptly, causing rapid and progressive
joint destruction.[3]
Despite the severity of Charcot arthropathy associated with syringomyelia if it is
not diagnosed early, there are still few case reports on the subject, especially in
cases related to syringomyelia. Thus, this study aimed to report two cases of Charcot
arthropathy caused by syringomyelia.
Case Report
Case 1
A 53-year-old man from the rural area of Cabrobó, in the state of Pernambuco, Brazil,
presented to the emergency department with clicking in the right shoulder for at least
12 months, associated with local swelling, pain, and limited range of joint motion.
He was a former smoker (quit smoking more than 10 years prior) and had a previous
prostate surgery due to urinary incontinence and benign prostatic hypertrophy. He
denied high blood pressure and diabetes. Neurological examination showed predominance
of right upper limb proximal monoparesis grade 3 muscle strength on the Medical Research
Counsil (MRC) scale, and distal grade-4 muscle strength, abolished deep tendon reflexes
in the upper right limb, hypotrophy of the suprascapular and lateral deltoid muscles,
and inability to abduct above 90 degrees, ipsilaterally ([Fig. 1]). A radiograph of the right shoulder in anteroposterior (AP) and profile views was
performed, showing significant joint destruction, with resorption of the head of the
right humerus ([Figs. 2A] and [2B]). The hypothesis of neoplasia and Charcot neuroarthropathy was raised, and magnetic
resonance imaging (MRI) of the shoulder and cervical spine was requested. Right shoulder
MRI showed bone destruction of the humeral head, with a liquid collection measuring
∼ 7.0 × 4.7 cm in the adjacent soft tissues ([Fig. 3]). Cervical spine MRI showed syringomyelic cavity extending from the C2 to the T3
level and diffuse degenerative disc disease predominantly at the C5-to-T1 level ([Fig. 4]). Neurosurgical treatment was proposed for occipitocervical decompression, but the
patient refused the procedure, even though he was aware of the risks of possible neurological
worsening. He is currently undergoing conservative treatment of neuroarthropathy with
neuroleptics and non-steroidal analgesics.
Fig. 1 Patient unable to abduct upper right limb of the arm from 90 degrees.
Fig. 2 Radiograph of upper limbs on coronal sections, showing destruction and absorption
of the humeral head.
Fig. 3 Magnetic resonance imaging (MRI) of the right shoulder in T1- (A) and T2-weighted
(B) sequence, in sagittal view, showing bone destruction of the humeral head with
adjacent fluid collection.
Fig. 4 Magnetic resonance imaging (MRI) of the cervical spine in T2-weighted sequence, in
sagittal section, showing extensive syringomyelic cavity extending from the C2 to
the T3 level.
Case 2
A 45-year-old man, a truck driver, from Salgueiro, in the state of Pernambuco, Brazil,
arrived at the neurosurgical department with pain in the right upper limb and difficulty
in joint motion for at least 24 months, associated with progressive worsening collection
and edema in the ipsilateral upper limb. He also presented paresthesia, loss of strength,
and inability to abduct the right upper limb ([Fig. 5A]). He denied high blood pressure, smoking, or diabetes. He was referred to an orthopedist,
who performed a puncture of the brachial collection. Laboratory analysis showed a
nonspecific chronic inflammatory process. The orthopedist proceeded with corticosteroid
infiltration and immunosuppressive treatment, with no improvement. On neurological
examination, he had grade-3 strength (MRC scale) in the right upper limb, signs of
hypotrophy in the deltoid muscle, and hyporeflexia grade 1 (National Institute of
Neurological Disorders and Stroke scale) in the ipsilateral upper limb. The deep tendon
reflexes in the other limbs were grade 3 on the National Institute of Neurological
Disorders and Stroke scale. He was unable to abduct the right upper limb from 45 degrees.
Humeral radiography showed complete destruction of the right humeral head with resorption
and signs of a local inflammatory reaction ([Fig. 6]). Right shoulder MRI showed marked heterogeneous fluid distension of the glenohumeral
joint cavity, associated with destruction of the humeral head, glenoid and rotator
cuff tendons, compatible with erosive inflammatory arthropathy ([Fig. 7]). Cervical spine MRI showed mild invagination of the cerebellar tonsils through
the foramen magnum, signs of diffuse degenerative disc disease, and extensive cervical
hydrosyringomyelia from C1 to T2 ([Fig. 8]). The right upper limb ultrasound showed a homogeneous collection involving the
humerus, measuring ∼ 7.6 × 7.0 × 6.6 cm (186 cm3) on its anterior view and 7.6 × 7.0 × 6.1 on its posterolateral view (172 cm3). Thus, dissection of the biceps brachii muscle through the anterior collection (∼
3 cm above the elbow) was performed. The hypothesis of Charcot neuroarthropathy secondary
to syringomyelia associated with humoral factors and chronic inflammatory response
was raised. Neurosurgical treatment was performed for posterior fossa decompression,
with suboccipital craniectomy, C1 vertebral arch resection and duraplasty. After surgery,
the patient had complete resolution of the inflammatory collection of the right brachial
soft tissues and improvement in distal muscle strength (grade 4 on the MRC scale).
Currently, the patient maintains the neurological condition and no progression of
osteoarticular disease of the humerus ([Fig. 5B]).
Fig. 5 Patient unable to elevate the right upper limb above 45 degrees before neurosurgical
treatment (A); After posterior occipitocervical decompression (B).
Fig. 6 Right upper limb radiograph on AP view, showing destruction and absorption of the
humeral head.
Fig. 7 Magnetic resonance Imaging of the right shoulder in T2-weighted (A) and short tau
inversion recovery (STIR) (B) sequence, in sagittal view, showing destruction of the
humeral head, glenoid and rotator cuff tendons, with a voluminous adjacent fluid collection.
Fig. 8 Cervical spine magnetic resonance imaging in T2-weighted sequence, in sagittal (A)
and axial (B) sections, showing extensive hydrosyringomyelia at the C1-to-T2 level.
Discussion
Neuropathic arthropathy was initially described by Mitchell in 1831, being fully characterized
for the first time in 1868 by Jean-Martin Charcot, correlated, at the time, with neuropathy
induced by tabes dorsalis (neurosyphilis). The first patient with neuropathic arthropathy
caused by syringomyelia was described by Sokoloff in 1892.[8] Charcot arthropathy in the shoulder is a progressive joint degeneration that develops
over years and is usually diagnosed only in advanced stages of neurological diseases,
the main one being syringomyelia of the cervical segments of the spinal cord.[9]
In syringomyelia, central fluid cavity present in the spinal cord causes progressive
destruction of the shoulder joint either by compression effects or by abnormal conduction.[10] Approximately 20 to 30% of patients with syringomyelia develop a secondary arthropathy
of the shoulder.[7] Syringomyelia is a rare disease that causes signs and symptoms such as massive bone
loss, high inflammation, and neurological abnormalities such as weakness, loss of
pain sensation, and arthropathy. In general, the affected shoulder presents a progressive
degeneration of the humeral head and glenoid.[5]
The pathophysiology of neuropathic arthropathy is not completely proven, and there
are two commonly accepted theories: neurovascular and neurotraumatic. The neurotraumatic
theory claims that joint destruction is caused by repeated microtrauma, as a consequence
of loss of proprioceptive and peripheral sensitivity resulting in macroscopic injuries
such as fractures, dislocations, and joint deformities. The neurovascular theory suggests
that peripheral neuropathy increases bone blood flow causing greater bone resorption
and osteopenia by osteoclasts. Fragile bones are more susceptible to fractures, lesions,
and joint destruction. Thus, it is believed that the junction of these two processes
is responsible for the progression of the disease.[1]
[3]
[5]
Early diagnosis is essential to prevent progressive joint destruction, since treatment
is based on the management of syringomyelia. Magnetic resonance imaging is the gold
standard for the diagnosis of syringomyelia. The progression of the disease can vary
from insidious cases, in which the patient is asymptomatic or with few symptoms, to
rapid progressions.[6] The purpose of treatment for patients with neuropathic arthropathy is to slow the
progression of the underlying disease and preserve joint functionality.[11] Conservative treatment consists of immobilizing the joint using orthosis and physical
therapy to prevent further episodes of trauma. Pharmacological treatment is performed
with non-steroidal anti-inflammatory drugs (NSAIDs) to decrease synovial inflammation.
Bisphosphonates and calcitonin are used to reduce osteoclastic activity.[12] In the case of surgical treatment, arthroplasty or arthrodesis is contraindicated
for most cases considering the high failure rates due to muscle weakness. The central
goal of neurosurgical treatment is to prevent cavity enlargement and damage to the
remaining parts of the spinal cord caused by syringomyelia.[5]
Conclusion
Charcot arthropathy is a differential diagnosis of pain, swelling and limited range
of motion in the shoulder joint. In patients with an unusual presentation of soft-tissue
diseases, in order not to miss the disorder diagnosis, craniocervical MRI scan should
be done to evaluate the presence of syringomyelia, in which the mainstay treatment
is posterior fossa decompression. The correct diagnosis and treatment are possible
by careful medical evaluation, and it can improve patient symptoms.
