Abstract Details

Title The clinical spectrum of acute nutritional axonal neuropathy (ANAN)

Topic Neuromuscular and Clinical Neurophysiology (EMG)

Presentation(s) S42 - Neuromuscular Disorders (4:58 PM-5:09 PM)

Poster/Presentation
Number 009

Background ANAN is a severe, symmetric, length-dependent, acute or sub-acute axonal polyneuropathy that occurs in the setting of nutritional deficiency (e.g., alcoholism, eating disorders, bariatric surgery) with marked weight loss, vomiting or diarrhea (Muscle Nerve 2018;57:33-39). Levels of micronutrients with short half-lives are low, most importantly thiamine, but also vitamin B6, folate, vitamin E, or copper. In our previous series, all patients were women and revealed a pure sensory or sensorimotor polyneuropathy.

Objective To describe the clinical and electrophysiologic spectrum of acute nutritional axonal neuropathy (ANAN) to enhance recognition and facilitate targeted treatment.

Design/Methods ANAN patients were identified by retrospective review of our EMG database and characterized by neuropathy type (pure sensory, sensorimotor, pure motor), presence of concomitant myopathy, associated clinical features (Wernicke’s encephalopathy, WE), and low vitamin levels.

Results

In our complete series of 22 ANAN patients (2 men), 13 were alcoholics, 6 were anorectic, and 3 had bariatric surgery. Their neuropathy was pure sensory in 6 (4 with low thiamine, 0 WE, 0 low B6), sensorimotor in 14 (4 with low thiamine, 3 WE, 9 low B6, 2 with myopathy), and pure motor in the 2 men (1 low thiamine, 0 WE, 1 low B6, 1 with myopathy).

Conclusions

The spectrum of ANAN is wide ranging from: 1) a pure sensory neuropathy with sensory ataxia to 2) a motor axonal neuropathy with low-amplitude motor responses with normal conduction velocities, and 3) a mixed sensorimotor axonal polyneuropathy with or without myopathy. The sub-group of ANAN patients with documented thiamine deficiency also range from pure sensory to pure motor, and only a minority have WE. It remains unclear whether co-existent micronutrient deficiencies or gender plays a role in the wide clinical spectrum of ANAN.

Authors/Disclosures
Johanna Hamel, MD (University of Rochester, Neurology) PRESENTER	Dr. Hamel has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Vertex Pharmaceuticals.
Eric L. Logigian, MD, FAAN (University of Rochester Medical Center)	Dr. Logigian has nothing to disclose.

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