Cervical lower motor neuron syndromes: A diagnostic challenge.

Area of Science:

• Neurology
• Radiology

Background:

• Cervical lower motor neuron (LMN) syndromes, or brachial paresis, present with upper limb muscle atrophy and weakness, lacking sensory deficits.
• Etiologies are diverse, including degenerative, immune-mediated, infectious, toxic, metabolic, and vascular causes.
• Misdiagnosis rates for LMN presentations approach 20%, highlighting the need for improved diagnostic strategies.

Purpose of the Study:

• To propose a novel classification system for cervical LMN syndromes.
• To enhance diagnostic accuracy by integrating MRI findings, symptom onset, atrophy patterns, and etiology.

Main Methods:

• Review of existing literature on cervical LMN syndromes.
• Development of a classification framework based on MRI characteristics.
• Categorization by symptom onset (acute, subacute, chronic), atrophy symmetry/distribution, and etiology (sporadic/hereditary).

Main Results:

• The proposed classification system integrates MRI findings, symptom timing, atrophy patterns, and etiological factors.
• Acute presentations may involve spinal ischemia, while subacute/chronic forms can be symmetric (e.g., spondylogenic myelopathy) or asymmetric (e.g., Hirayama disease).
• Neurophysiological studies and cervical MRI are vital for localization and etiological clues.

Conclusions:

• A systematic diagnostic approach incorporating the proposed classification is essential.
• Accurate diagnosis of cervical LMN syndromes requires integrating clinical, neurophysiological, and advanced imaging data.
• The classification aims to reduce diagnostic errors and guide appropriate management.