If a patient with cervical spondylosis experiences involuntary head shaking, it may be due to the presence of increased differential pulse pressure, central neuropathy, or muscle spasm, among other causes. The specific causes are as follows: 1. Increased pulse pressure difference: When the patient has an attack of the disease, the blood supply to the brain will be insufficient due to the stimulation of the sympathetic nerve and the compression of the vertebral artery. At this time, the patient’s blood pressure will reflexively increase. Some patients also experience an increase in the difference in pulse pressure between the systolic and diastolic blood pressures, which can lead to involuntary head nodding. This symptom is called peripheral vascular sign. 2. Central neuropathy: Some patients may suffer from long-term insufficient blood supply to the brain due to cervical spondylosis. This may lead to hypoxia of the brain cells, and sometimes may even cause extrapyramidal lesions, such as Parkinson’s syndrome. At this time, the patient will often have the above symptoms of involuntary shaking. 3. Muscle spasms: patients with episodes of cervical spondylosis may experience muscle spasms in the neck and neck area, causing patients to feel localized pain, stiffness and constriction. And patients tend to tilt or swing their heads involuntarily in order to relieve this pathological change. It is recommended that patients experiencing these symptoms must visit an orthopedic or neurologist, etc., to clarify the cause of the condition and for further treatment.