A 55-year-old woman with end-stage renal failure due to chronic glomerulonephritis was hospitalized for severe pain, numbness and paresthesia in both wrists, with progressive paralysis of the thenar muscles and both shoulders' pain for about 1 year. She had been on maintenance hemodialysis for 14 years at Chonnam University Hospital. Dialysis had been performed for 4 hours, 3 times weekly with hollow-fiber cuprophan dialyzers that were not reused. She had been on hemodialysis therapy since 1983 via a side to side cephalic vein-radial artery arteriovenous fistula in the left distal forearm and then, 5 years later, arteriovenous fistula in the right distal forearm due to loss of the function of the left arteriovenous fistula. Maintenance hemodialysis had been continued using this fistula. Symptoms mentioned above had been aggravated during hemodialysis and often awakened her at night.
On admission, blood pressure was 90/60mmHg, body temperature 37 C, pulse rate 94/min and respiration rate was 22/min. On physical examination, she was alert, obese and a chronically ill-looking appearance. She had pale conjunctiva and anicteric sclerae. Physical examination showed positive Phalen's wrist flexion test and positive Tinel's test at the wrist with thenar muscle atrophy. Her both knee joints were markedly swelled and their motions were moderately limited. On auscultation, her heart beat was regular and no murmur was heard. Her breathing sound was clear and no abnormal sound was heard. On abdominal palpation, liver, spleen or kidneys were not palpable. Peripheral lymph nodes were also not palpable. She had not suffered from tuberculosis or diabetes mellitus, but she had a trauma history at the right knee joint and the right thumb 4 years ago.
Laboratory findings were as follows: red blood cell count 2.87 x 106/mm3, white blood cell count 5.7 x 103/mm3, hematocrit 23.7%, hemoglobin 8.1 g/dL, platelet 179x 103/mm3 and the reticulocyte count 3.3%. Peripheral blood smear showed microcytic and hypochromic anemia (MCV: 80.3 fl, MCHC: 32.1%) with anisocytosis but preserved platelet and white blood cell counts. Blood chemistry studies showed serum electrolyte were normal, except for total serum calcium 8.1mg/dl and inorganic phosphate 6.6mg/dl. The AST was 65IU/I, ALT 51IU/I, alkaline phosphatase 143IU/I (liver origin 71.7%, and bone origin 28.3%), total bilirubin 0.4mg/dl, total serum protein 7.1g/dl and albumin 3.5g/dl, globulin 3.6g/dl and LDH 509IU/I. Renal function test revealed serum creatinine 8.6mg/dl, and blood urea nitrogen 44mg/dl and other laboratory tests showed that rheumatoid factor was 20IU/ml, C-reactive protein 2.8mg/dl, serum ferritin 210ng/ml, the erythrocyte sedimentation rate 78 mm/hr, serum beta2-microglobulin 60.5ug/l (normal: 1.1 to 2.7mg/ml), intact parathyroid hormone 147pg/ml, 1alpha, 25(OH)2D3 8.9pg/ml (normal: 16 to 45pg/ml) and serum osteocalcin 13.9ng/ml (normal: 4 to 12ng/ml).
Radiologic examination showed bony destructive changes at right first interphalangeal joints in both hands and narrowing of joint space in right knee joint and bony destructive lesions with sclerotic border of left tibial plate, but otherwise nonspecific. Bone mineral density was examined, and the total body bone mineral density of our patient was within normal limit (1.191+-0.0 g/cm2), compared with the normal controls (control group: 1.15+- 0.10g/cm2). Whole body bone scan showed that hot spot uptake was noted in the areas of middle phalanx of right thumb, 4th and 5th left posterior ribs, left carpal bones, right distal femur and right lower sacroiliac joint.
Electrocardiography showed left ventricular hypertrophy, but otherwise nonspecific. Echocardiogram showed marked concentric hypertrophy with diastolic dysfunction.
Electromyographic examinations were performed in both median motor and sensory nerves: Nerve conduction studies demonstrated delayed distal latency and conduction velocity in both median motor nerves, and sensory nerves were not evoked and these findings were compatible with compression of the median nerves within the carpal tunnels (left side was more severely involved). Needle electromyography showed profusely abnormal spontaneous activities at rest and increased polyphasic Voluntary Motor Unit Action Potentials (MUAP) on minimal vibration in both abductor pollicis brevis innervated by median nerves.
On 7th hospital day, abdominal fat aspiration biopsy was done, and the biopsy was negative for amyloid on Congo red staining. On 15th hospital day, she underwent an open surgical release and epineurolysis at the left carpal tunnel with an impression of carpal tunnel syndrome. At the time of the surgical release and exploration of the carpal tunnel in left hand, she had moderate thickening of the transverse carpal ligament, hyperemia of the median nerve epineurium and compression and narrowing of the median nerve. Flexor tenosynovial hypertrophy on the left wrist and degeneration of transverse carpal ligament and synovium were seen, and dilatation of proximal fragment of left median nerve was also seen. Epineurolysis of left median nerve and left synovectomy were performed.
Histologic examinations of the transverse carpal ligament and epineurium of median nerve for amyloid deposition by Congo red staining, fluorescence microscopy and electronmicroscopy were performed. These tissues specimens showed multifocal amorphous pinkish deposits in the dense collagenous fibrous bundles in light microscopy, and red colored in hematoxylin and eosin, and Congo red staining (Fig. 1). The amyloid protein with Congo red staining exhibited apple-green birefringence under polarized light microscopy (Fig. 2) and electron microscopic examination showed numerous short but thick, nonbranching curvilinear fibrills aligned in parallel and aggregated in bundles (Fig. 3).
After surgical release of CTS, she had dramatic relief of pain and numbness in left hand and wrist joint during dialysis at night, did well for the following 3 months.