ABSTRACT
Objective To investigate cervical spinal upper motor neuron (UMN) dysfunction in patients with frail arm syndrome (FAS) by physical examination,triple stimulation technique (TST) and pectoralis tendon reflex tests.Methods Sixty-seven FAS patients,coming from Peking University Third Hospital from June 2013 to June 2016,underwent physical examination and routine electrophysiological tests.The pyramid signs,the results of pectoralis tendon reflex and TST were collected to estimate the function of cervical spinal UMN.Results On the time of diagnosis,weakness of bilateral proximal upper limbs was found in 61 patients,while weakness of unilateral proximal upper limb was found in six patients.There were 25 patients with tendon hyperreflexia,20 patients with tendon hyporeflexia and 22 patients with tendon areflexia.All the patients were pectoral muscle tendon hyperreflexia except one.UMN score of cervical region was 2.0 ± 0.5.Lower motor neuron score of cervical region was 2.0 ± O.2.The amplitude ratio of TSTtest/TSTcontrol was 78.31％ ± 6.52％.The latency and amplitude of quantitative detection of pectoralis tendon reflex was (7.80 ± 1.22) ms and (1.23 ± 0.14) mV,respectively.In the follow-up study,the tendon reflexes and the UMN score declined,the amplitude ratio of TSTtest/TSTcontrol decreased,while the lower motor neuron score increased and the latency of quantitative detection of pectoralis tendon reflex remained almost unchanged.Conclusion The results showed that there was cervical spinal UMN dysfunction in patients with FAS,and the pyramid signs were often concealed by muscle atrophy with progression of the disease.