The Huashan diagnostic criteria and clinical classification of Hirayama disease

Objective To establish Huashan diagnostic criteria and clinical classification system for Hirayama disease. Methods Retrospective analysis 359 cases of puberty onset, upper extremity muscle atrophy as main clinical manifestations, and complete clinical data from September 2007 to August 2018. There were 348 males and 11 females (31.6∶1 male and female) in this group. The average age of onset was 16.7±2.2 years, the average age of visits was 19.2±4.5 years, and the average duration of treatment was 29.3±45.4 months. Descriptive study of the clinical manifestations, radiologic and neurophysiological findings of this group of patients, the Huashan clinical diagnostic criteria of Hirayama disease were established by including 100% of the clinical manifestations, imaging and neurophysiological findings. According to the following parameters, the clinical classification system of Hirayama disease was proposed. The parameters specifically included: the muscle atrophy involves the upper limbs, whether the quadriplegia was active or hyperactive, the Babinski sign positive and other pyramidal tract damage, whether it was accompanied by sensory dysfunction such as upper limb numbness, muscle atrophy location, and the progress of clinical symptoms or electrophysiological examination within 6 months. Thirty patients were randomly selected from the above 359 cases. Four orthope dic surgeons who were not involved in the classification system completed the clinical classification within the specified time. The Kappa value was used for the credibility evaluation. Results The Huashan diagnostic criteria of Hirayama disease included clinical manifestations, imaging examinations and neurophysiological examinations. The main diagnostic indicators were: 1) occult onset puberty, more common in men; 2) localized muscle atrophy and weakness in the upper extremities; 3) compared with the cervical neutral MRI, the MRI of cervical flexion showed that spinal cord was significantly shift forward and the anterior spinal cord was narrowed or disappeared. 4) MRI T2 weighting of the cervical flexion showed cyst-wall separation behind the spinal cord; 5) Neurophysiological examination showed that the affected muscles were neurogenic damage. 6) The affected parts are limited to the middle and lower neck segment. At the same time, it was necessary to combine imaging and neurophysiological manifestations to distinguish cervical spondylosis with upper limb muscle atrophy and motor neuron disease. According to the clinical characteristics of different patients, Hirayama disease can be divided into type I-III. Type I: 72.1%, one-sided upper limb or one upper limb-based hand inner muscle and forearm muscle atrophy. According to whether progress of symptoms or electrophysiological examination was seen in the past 6 months, type I can be divided into: Ia. stable period. Regular follow-up assessment was recommended. If the disease progressed, to wear a cervical collar was suggested; surgery could be done if necessary; Ib. progression period, it was recommended to use a cervical collar, and regularly evaluate. if patients could not wear cervical collar for long, it was recommended to operate. Type II: 14.2%, unilateral upper limb or one upper limb-based hand inner muscle and forearm muscle atrophy with pyramidal tract injury. Surgery was recommended. Type II: 13.7%, atypical Hirayama disease, including upper limb proximal muscle atrophy, symmetrical double upper limb muscle atrophy, and sensory disturbances associated with upper limb numbness. Wear a cervical collar, and follow-up and assess closely, and choose surgical treatment if necessary. The credibility evaluation showed that the average Kappa value of the classification was 0.732 (0.688-0.834), which is a basic credibility. Conclusion The Huashan diagnostic criteria of Hirayama disease was conducive to the early diagnosis. The clinical classification system of Hirayama disease has good credibility and good clinical intervention guidance value. Key words: Cervical vertebrae; Spinal cord compression; Upper extremity; Muscular atrophy; Diagnosis