Motor neuron disease encompasses:
(1) amyotrophic lateral sclerosis (ALS)
(2) primary lateral sclerosis
(3) progressive muscular atrophy
(4) progressive bulbar palsy
When to suspect the possibility of a paraneoplastic MND:
(1) clinical improvement after a tumor is treated
(2) elevated protein in the CSF
(3) monoclonal protein in the serum
(4) anti-Hu or other neurologic autoantibody in the peripheral blood
(5) diagnosis of small cell lung cancer, breast cancer or malignant lymphoma preceding or following onset (onset of a paraneoplastic disorder may be 1-2 years before the tumor is diagnosed)
(6) atypical features for the motor neuron disease