Evaluation of Cases Diagnosed with Cervical Myelopathy or Syringomyelia Referred with a Preliminary Diagnosis of Amyotrophic Lateral Sclerosis

Objective: Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease involving both upper and lower motor neurons. Upper motor neuron signs include spasticity and hyperreflexia, while lower motor neuron signs include weakness, muscle atrophy, and fasciculations. Because of these signs, ALS can be confused with cervical spondylotic myelopathy (CSM), syringomyelia, and similar diseases. This study aimed to evaluate the clinical and demographic characteristics of patients diagnosed with CSM or syringomyelia after initially being referred with suspected ALS. Materials and Methods: Ten patients referred to our neurology clinic between January 2018 and June 2020, with a preliminary diagnosis of ALS, were evaluated. Those patients later diagnosed with CSM or syringomyelia after neurological examination, including electromyography (EMG) and magnetic resonance imaging (MRI), were included in the study. Results: Ten patients (mean age 65.6 years) were analysed. Thenar and hypothenar atrophy was observed in 8 patients (80%). EMG revealed fasciculations and subacute denervation in cervical myotomes in all patients; 1patietnt had lumbar involvement. EMG of rectus abdominis and genioglossus muscles was normal. Thenar and hypothenar atrophy, fasciculation, and denervation in cervical and lumbar myotomes on EMG are similar to ALS signs. A normal rectus abdominis and genioglossus muscle EMG excludes the diagnosis of ALS. Conclusions: CSM and syringomyelia should be considered in the differential diagnosis of ALS. A detailed history, neurological examination, EMG, and MRI are essential for diagnostic accuracy.