In patients with dry syndrome, neurological involvement is not uncommon, and the international reports on the incidence of neurological lesions are different, the incidence of combined peripheral neurological lesions in patients with dry syndrome is about 10% to 60%, and the incidence of combined central neurological lesions is relatively small, the incidence is between 2% and 25%, the reason for such a large difference in incidence may be: at present, the international standard for combined neurological lesions in dry syndrome has not been unified, and the prevalence of different populations also differs greatly. The reason for such a big difference in the incidence may be that the international diagnostic standard of combined neurological lesions in dry syndrome has not been unified yet, and the prevalence rate of different populations also has big differences, but in general, neurological involvement is not uncommon in dry syndrome. Neurological lesions are divided into peripheral neurological lesions and central neurological lesions, and their clinical manifestations are various, and we will explain them from these two aspects: peripheral neurological lesions (1) sensory neurological lesions, such as burning sensation in hands and feet, pain in extremities, etc.; (2) sensory-motor neurological lesions; (3) multiple single neurological lesions; (4) autonomic neurological lesions: autonomic neurological lesions of the urinary system can show increased nocturia, frequent and urgent urination in the daytime, and (5) autonomic neurological lesions. (4) autonomic neuropathy: autonomic neuropathy of the urinary system may include increased nocturia, frequent and urgent urination during the day, urinary incontinence, straining to urinate, and incomplete urination (except for renal tubular acidosis, urinary tract infection, and prostatic hyperplasia), and intestinal dysfunction, such as diarrhea, constipation, or alternating diarrhea and constipation; (5) peripheral neuropathy, which is more common in peripheral neuropathy. (6) cranial neuropathy, which can involve the olfactory nerve, optic nerve, facial nerve, and auditory nerve, but the most common one is trigeminal neuralgia. If you have abnormal sensation in the extremities, especially numbness in both hands and feet, you should be alert to the combination of peripheral neurological lesions, and need to go to the specialist clinics (rheumatology and neurology) in time. Central nervous system lesions Lesions can involve the brain and spinal cord. Brain lesions include mainly focal and diffuse lesions. Focal lesions are mainly manifested by aphasia, seizures, dysarthria, visual impairment, local sensory and motor abnormalities; diffuse lesions are mainly manifested by subacute or acute encephalopathy, aseptic meningoencephalitis, psychological and cognitive impairment. Cognitive dysfunction is the most common clinical manifestation in patients with mild cognitive impairment, mainly frontal lobe executive function abnormalities and memory impairment. In addition, the central nervous system can also involve the spinal cord, mostly in the form of acute transverse myelitis, chronic progressive myelopathy, and neurogenic bladder, and acute transverse myelitis can sometimes be the first manifestation of dry syndrome and other immune diseases such as lupus erythematosus. Electrophysiological and imaging examinations Electromyography and nerve conduction velocity are extremely important for the diagnosis of peripheral nervous system lesions. Prolonged action potential time frame, slowed nerve conduction velocity and reduced wave amplitude are all indicative of neurogenic damage. The sensitivity of cranial MRI in diagnosing dry syndrome combined with central nervous system lesions is high, about 80% of patients show progressive focal neurological abnormalities, and patients with cranial MRI can see multiple small focal T2 signal hyperintensities mainly in the subcortical and paraventricular white matter, and some patients can see cortical and cerebellar atrophy or ventricular dilatation. However, the significance of MRI in the diagnosis of diffuse CNS lesions is uncertain. The probability of cranial MRI abnormalities in patients without CNS manifestations is low. Pathogenesis of neurological lesions The pathogenesis is unclear, and some studies have suggested that sensorimotor neuropathy, autonomic neuropathy, and trigeminal neuralgia are associated with gangliositis. Some pathological biopsies suggest that the pathological mechanism may be vasculitis, mainly involving small vessels, predominantly small and medium-sized veins, but also small arteries. In addition, humoral immunity plays an important role in neuropathy. Some studies have shown that anti-DRG antibodies are present only in patients with primary dry syndrome combined with neuropathy, and others have suggested that anti-muscarinic receptor type 3 antibodies inhibit cholinergic neurotransmission and thus play an important role in neuropathy of the intestine and bladder. Treatment of neurological lesions The treatment of primary dry syndrome combined with neurological lesions is largely empirical, and no large-scale clinical trials have so far confirmed the therapeutic effects of hormones and immunosuppressive agents. The literature reports that glucocorticoids and immunosuppressants are mostly used, and the results of some studies show that the condition of most patients can be stabilized and remitted by adding immunosuppressants to the application of hormones. When the disease is active and progressive, hormone therapy can be given, and for those who are hormone insensitive, immunosuppressants can be added, of which cyclophosphamide is the most commonly used, and for patients who are insensitive or intolerant to cyclophosphamide, other immunosuppressants (including azathioprine and methotrexate) can be applied. For patients with refractory recurrent disease, studies have shown that plasma exchange and high-dose gammaglobulin are effective. In conclusion, it is not uncommon for patients with desiccation syndrome to have combined neurological lesions, so it is necessary to draw the attention of clinicians and patients to better control the disease and improve the quality of life.