Differential Diagnosis for Sensory Axonal Polyneuropathy
Single Most Likely Diagnosis
- Diabetic Neuropathy: This is a common cause of sensory axonal polyneuropathy, especially given the presence of chronic neurogenic changes on EMG. Diabetes can cause a length-dependent neuropathy that spares the compound muscle action potential (CMAP) initially, affecting sensory nerves more prominently.
Other Likely Diagnoses
- Alcohol-Related Neuropathy: Chronic alcohol abuse can lead to a sensory-predominant axonal polyneuropathy. The extensive denervation and chronic neurogenic changes on EMG are consistent with long-standing alcohol use.
- Vitamin Deficiency (B12, B6): Deficiencies in these vitamins can cause neuropathies that are predominantly sensory. B12 deficiency, in particular, can lead to extensive neurological damage if not treated promptly.
- Idiopathic Axonal Neuropathy: Some cases of axonal neuropathy remain idiopathic after thorough investigation. These cases can present with sensory predominant symptoms and extensive denervation on EMG.
Do Not Miss Diagnoses
- Amyloidosis: Although rare, amyloidosis can cause a sensory-predominant neuropathy and is crucial to diagnose due to its potential for systemic involvement and the availability of specific treatments. Missing this diagnosis could have significant implications for patient management and prognosis.
- Paraproteinemia (e.g., MGUS): Conditions like monoclonal gammopathy of undetermined significance (MGUS) can lead to neuropathy. Identifying these conditions is critical because they may progress to more serious diseases like multiple myeloma or amyloidosis.
- Toxic Neuropathy: Exposure to certain toxins (e.g., heavy metals like arsenic, lead, or mercury) can cause neuropathies. Identifying and removing the toxin is essential for preventing further damage.
Rare Diagnoses
- Sjögren's Syndrome: This autoimmune disorder can cause a sensory neuropathy. While less common, it's an important consideration due to its association with other systemic symptoms and the potential for specific treatments.
- Mitochondrial Disorders: Certain mitochondrial disorders can present with neuropathy, among other systemic symptoms. These are rare but important to consider, especially in younger patients or those with a family history of similar conditions.
- Inherited Neuropathies (e.g., Hereditary Sensory and Autonomic Neuropathy, HSAN): These are rare genetic disorders that can cause significant neuropathic symptoms. They are usually identified in childhood but can sometimes present later in life.