Carpal tunnel syndrome is an entrapment neuropathy. Affects about 5% of adults (1 in 20). Etiology can include repetitive maneuvers but also secondary to other diseases. Symptoms include hand pain, numbness, and tingling. Nerve conduction studies useful in confirming clinical suspicion. Initial treatment for mild symptoms include lifestyle changes such as ergonomics and decreasing repetitive actions, but this treatment has inconsistent results. Wrist splints and oral corticosteroids considered first line therapy. Moderate to severe disease is treated surgically.

HIGHLIGHTS:

*May affect a single or multiple organs, cardiac and renal involvement common
*Diagnosis is considered in patients with nondiabetic nephrotic syndrome, nonischemic cardiomyopathy with concentric hypertrophy, elevated NT-proBNP with the absence of primary heart disease
*Often presents with unexplained weight loss, fatigue, and edema
*Male > female
*Most common type is immunoglobulin light chain amyloidosis (AL amyloidosis)
*There is no known preventive measures for primary amyloidosis. For secondary amyloidosis from uncontrolled inflammation and hepatic production of serum amyloid, treatment of the underlying inflammatory condition reduces progression to amyloidosis

RISK FACTORS:

*Etiology unknown for primary amyloidosis
*monoclonal gammopathy of undetermined significance
*inflammatory polyarthropathy
*chronic infections
*inflammatory bowel disease

SYMPTOMS:

*Amyloidosis can affect the heart, leading to heart failure and associated symptoms
*Dyspnea on exertion
*Fatigue
*Weight loss

PHYSICAL:

*Jugular venous distention
*Peripheral edema from nephrotic syndrome and/or heart failure
*Periorbital purpura
*Hepatomegally
*Macroglossia

LABORATORY TESTS:

*Immunofixation of serum and urine => monoclonal light chains.
*Tissue biopsy performed for a definitive diagnosis
*Urinalysis (proteinuria)
*EKG (low voltage)
*NT-proBNP

IMAGING TESTS:

*For suspected cardiac amyloidosis: echocardiography

DIFFERENTIAL DIAGNOSIS:

*Hypertrophic cardiomyopathy
*Multiple myeloma
*Monoclonal gammopathy of undetermined significance

TREATMENT:

*Treatment highly individualized
*Manage clinical syndromes: nephrotic syndrome, cardiomyopathy, conduction disorders
*Definitive treatment: may include chemo0therapy, stem cell reconstitution

FOLLOW-UP:

*Prognosis primarily depends upon cardiac involvement
*For patients with AL amyloidosis, the 10-year cummulative survival is 31%
*Major consequences come from cardiac involvement and subsequent complications

REFERENCES:

*J Clin Oncol. 2011 May 10;29(14):1924-33. Epub 2011 Apr 11.
*ePocrates