Blackout at Rest and Slurring in a Man Afraid of COVID-19

Ankit Raiyani, MBBS, MD, DNB (Hematology)


March 03, 2021

After systemic amyloidosis, the second most probable diagnosis in the differential is diabetic nephropathy and autonomic neuropathy. Type 2 diabetes with poor glycemic control may cause end-organ damage. The heart, kidneys, peripheral and autonomic nervous systems, and blood vessels are among the most commonly affected organs.[2] Diabetic nephropathy can cause nephrotic-range proteinuria with declining renal function, which can lead to anasarca, heart failure, severe fatigue, and renal failure.[3,4] Autonomic neuropathy can explain this patient's symptoms of postural hypotension, palpitations, and frequent loose bowel movements. However, his easy bruising, recurrent cardiac arrhythmias, low voltage on an ECG, and macroglossia cannot be explained by diabetes complications.

Protein-losing enteropathy (PLE) is a condition in which an excess loss of proteins occurs through the gastrointestinal tract. PLE can be caused by more than 60 different conditions, including nearly all gastrointestinal diseases. It should be suspected in patients who have low serum protein levels and in whom other causes of hypoproteinemia have been ruled out.[5]

The leg swelling, periorbital puffiness, and low serum protein levels observed in this patient could be explained by PLE. Loose bowel movements can result from an underlying gastrointestinal condition. Palpitations can occur with the congestive heart failure associated with severe hypoproteinemia. However, the easy bruising, macroglossia, and cardiac arrhythmias observed in this patient are not usually associated with PLE.

Connective tissue disorders such as systemic lupus erythematosus can involve the kidneys. In lupus nephritis, the autoimmune response damages the renal tubules. Proteinuria develops in nearly all patients, and nephrotic-range proteinuria is observed in almost 50% of patients.[6] Loss of serum proteins in the urine can lead to anasarca, heart failure, severe fatigue, and renal failure.

Hypertension, hematuria, and granular casts in the urine develop in the majority of patients with lupus nephritis. These findings are absent in the patient in this case. In addition, this diagnosis cannot explain the other symptoms of the patient, including macroglossia, easy bruising, frequent loose bowel movements, and postural hypotension.

Similarly, nephrotic syndrome due to other conditions may result in anasarca, heart failure, severe fatigue, and renal failure. However, nephrotic syndrome does not cause arrhythmia, macroglossia, easy bruising, frequent loose bowel movements, and postural hypotension, which were observed in this patient.

The workup for systemic amyloidosis consists of these steps[1]:

  • Confirmation of the diagnosis

  • Classification of amyloidosis

  • Assessment of end-organ damage

The diagnosis is confirmed with biopsy of an affected organ (eg, skin, kidney, abdominal fat pad, or bone marrow trephine). Amyloid material stains with Congo red stain (Figure 1) and gives a characteristic apple-green birefringence on polarized microscopy (Figure 2). This finding is diagnostic of amyloid and is almost universally reported as evidence of amyloidosis.[7]

Figure 1.

Figure 2.

The classification of AL amyloidosis involves these studies:

  • Immunofixation electrophoresis

  • Serum free light chain assay

  • Bone marrow aspiration and biopsy

  • Whole body PET/CT scanning

These studies are used to classify AA amyloidosis:

  • C-reactive protein level, erythrocyte sedimentation rate, and ferritin level

  • Rheumatoid factor assay

  • Workup for tuberculosis

The assessment of end-organ damage includes these studies:

  • Serum creatinine level, estimated glomerular filtration rate, and 24-hour urine protein collection

  • Complete blood cell count, prothrombin time, and activated partial thromboplastin time

  • Liver function tests

  • ECG

  • NT-proBNP and troponin T/I levels

  • Fecal occult blood test

  • Nerve conduction study


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.
Post as: