To perform an observational retrospective cross-sectional case-control study to evaluate prevalence, clinical patterns and outcomes of neurological involvement in a cohort of Primary Sjögren Syndrome (pSS) patients followed up in a single center.
From a total of 93 pSS patients, diagnosed according to the 2002 criteria proposed by the American-European Consensus Group, we reviewed the clinical data of those with neurological complaints that were referred to observation by Neuroimmunology doctors. Demographic, clinical, seroimmunological data were compared between patients with and without neurological involvement.
Neurological involvement was detected in 26 (28%) of the 93 patients. Neurological symptoms preceded the diagnosis of pSS in 12 (46%) patients. They were all females. The mean age at disease onset and neurological onset were 41,2 and 47,9 years, respectively. Twelve patients (46%) had peripheral system involvement (PNS), 13 (50%) patients had central nervous involvement (CNS) disorders and one (4%) patient had both PNS and CNS involvement. In patients with PNS, pure sensory neuropathy (small fiber neuropathy confirmed by quantitative sensory testing and sural neuropathy) occurred most frequently (n =5), followed by cranial nerve involvement affecting trigeminal, facial, or trochlear nerves (n = 4). Multiple mononeuropathy (n = 1), sensorimotor polyneuropathy (n=1), autonomic neuropathy (n=1) and myasthenia gravis (n = 1), were also observed. In patients with CNS disorders, headache (n=3) occurred most frequently, in two patients with MRI abnormalities compatible with inflammatory disease. Spinal cord involvement (n=2), seizures (n = 2), motor and sensory deficit (n=2), movement disorders (n=2), neuromyelitis optica (n=2), aseptic meningitis (n=1) were others manifestations observed. Cognitive dysfunction was observed in 3 of these patients. The frequency of constitutional symptoms (such as fever and fatigue) and lung involvement was significantly higher (p< 0,05) and the articular symptoms were significantly less frequent (p< 0,05) in pSS with neurological involvement. The neurologic outcome was good in 77% of the patients.
The current study underlines the diversity of neurologic complications of pSS. The frequency of neurologic manifestations as first manifestation of pSS, especially in the event of CNS involvement, could explain why SS is frequently under diagnosed or late diagnosed. Screening for SS should be systematically performed in cases of acute or chronic myelopathy, axonal sensorimotor neuropathy, or cranial nerve involvement.