History and physical examination If the patient’s condition allows, take a detailed history of multiple sclerosis, diabetes mellitus, central nervous system infection, tumor, prior stroke, family history of ataxia, chronic alcoholism and industrial poisoning such as mercury poisoning. To understand whether the ataxia is sudden or progressive, the Romberg test was performed to distinguish cerebellar from sensory ataxia. The patient is placed in an upright position with the feet together and the upper extremities on the side of the body. The patient’s posture and balance are noted and the eyes are first opened and then closed. The results will suggest normal posture and balance, cerebellar ataxia (body swaying, failure to maintain balance, both with eyes open and closed), and sensory ataxia (increased swaying, failure to maintain balance with eyes closed). The patient should be examined close to the patient to prevent falls. When examining gait and limb ataxia, pay attention to checking muscle strength. If gait ataxia is serious, ask the patient if there is a tendency to fall to one side and if it is worse at night. Patients with trunk ataxia when lying down, hysteria (hysteria [translation]: is a class of neuropsychiatric disorders caused by mental stimulation or adverse suggestion.) , alcohol intoxication when its manifestations disappear. Physical examination 1. Finger-nose test: In ataxia, the patient’s movements may vary in weight and speed, and he may point to the target by mistake or only after adjustment. In the case of cerebellar hemisphere lesions, the closer the ipsilateral side is to the target, the more pronounced the ataxia is, and the poor distance discrimination can often exceed the target. In sensory ataxia, there is no impairment of ataxic movement with eyes open, but there is obvious ataxia when eyes are closed. 2.Heel, knee and shin test: When the cerebellar damage lifts the leg and touches the knee, the patient often sways unsteadily when moving down because of poor distance discrimination and intentional tremor; in sensory ataxia, the patient’s heel often cannot find the knee and sways unsteadily when moving down. 3.Rapid alternation test: When the cerebellum is damaged, the movement is clumsy and the rhythm is uneven. 4, rebound test: when cerebellar lesions. Patients often lead to excessive movements and whack themselves. 5. Over-finger test: In vestibular ataxia, the upper limb descends in favor of the side of the vagus with lesions; in sensory ataxia, the examiner’s finger is often not found when the eyes are closed. 6.Toe-finger test: The patient lies on his back and raises the big toe to touch the outstretched finger. 7.Sit-up test: Patients with cerebellar damage have the medulla and trunk flexed at the same time, and both lower limbs are raised, which is called the joint flexion sign. Ancillary tests 1, cerebellar ataxia should be examined by brain CT or MRI to exclude cerebellar tumors, metastases, tuberculomas or abscesses and vascular disease and cerebellar degeneration and atrophy. If the lesion is located in peripheral nerve, electromyography and somatosensory evoked potentials should be examined; if the lesion is considered in posterior root lesion or posterior cord lesion, electromyography, evoked potentials, MRI of the lesion, cerebrospinal fluid examination, or myelography should be examined. It is better to check brain CT or MRI when considering thalamus or parietal lobe. 3.Brain ataxia should check brain CT or MRI, EEG, etc. 4.Vestibular ataxia can be examined by electrical audiometry, auditory evoked potentials, vestibular function examination, etc.