Central and peripheral neurological complications of primary Sjögren's syndrome

Use of a novel high-resolution magnetic resonance neurography protocol to detect abnormal dorsal root Ganglia in Sjögren patients with neuropathic pain: case series of 10 patients and review of the literature

The diagnosis and treatment of patients with Sjögren syndrome (SS) with neuropathic pain pose several challenges. Patients with SS may experience unorthodox patterns of burning pain not conforming to a traditional "stocking-and-glove" distribution, which can affect the face, torso, and proximal extremities. This distribution of neuropathic pain may reflect mechanisms targeting the proximal-most element of the peripheral nervous system-the dorsal root ganglia (DRG). Skin biopsy can diagnose such a small-fiber neuropathy and is a surrogate marker of DRG neuronal cell loss. However, SS patients have been reported who have similar patterns of proximal neuropathic pain, despite having normal skin biopsy studies. In such cases, DRGs may be targeted by mechanisms not associated with neuronal cell loss. Therefore, alternative approaches are warranted to help characterize abnormal DRGs in SS patients with proximal neuropathic pain.We performed a systematic review of the literature to define the frequency and spectrum of SS peripheral neuropathies, and to better understand the attribution of SS neuropathic pain to peripheral neuropathies. We found that the frequency of SS neuropathic pain exceeded the prevalence of peripheral neuropathies, and that painful peripheral neuropathies occurred less frequently than neuropathies not always associated with pain. We developed a novel magnetic resonance neurography (MRN) protocol to evaluate DRG abnormalities. Ten SS patients with proximal neuropathic pain were evaluated by this MRN protocol, as well as by punch skin biopsies evaluating for intraepidermal nerve fiber density (IENFD) of unmyelinated nerves. Five patients had radiographic evidence of DRG abnormalities. Patients with MRN DRG abnormalities had increased IENFD of unmyelinated nerves compared to patients without MRN DRG abnormalities (30.2 [interquartile range, 4.4] fibers/mm vs. 11.0 [4.1] fibers/mm, respectively; p = 0.03). Two of these 5 SS patients whose neuropathic pain resolved with intravenous immunoglobulin (IVIg) therapy had improvement of MRN DRG abnormalities.We have developed a novel MRN protocol that can detect DRG abnormalities in SS patients with neuropathic pain who do not have markers of peripheral neuropathy. We found that SS patients with MRN DRG abnormalities had statistically significant, increased IENFD on skin biopsy studies, which may suggest a relationship between trophic mediators and neuropathic pain. Given that our literature review has demonstrated that many SS neuropathic pain patients do not have a neuropathy, our findings suggest an important niche for this MRN DRG technique in the evaluation of broader subsets of SS neuropathic pain patients who may not have underlying neuropathies. The improvement of MRN DRG abnormalities in patients with IVIg-induced remission of neuropathic pain suggests that our MRN protocol may be capturing reversible, immune-mediated mechanisms targeting the DRG.

White matter water diffusion changes in primary Sjögren syndrome

BACKGROUND AND PURPOSE

Histopathologic studies have demonstrated WM damage in primary Sjögren syndrome. The purpose of this study was to evaluate WM microstructural changes by use of DTI-derived parameters in patients with primary Sjögren syndrome.

MATERIALS AND METHODS

DTI was performed in 19 patients with primary Sjögren syndrome (age, 64.73 ± 9.1 years; disease duration, 11.5 ± 7.56 years) and 16 age-matched control subjects. Exclusion criteria were a history of major metabolic, neurologic, or psychiatric disorder and high risk for cardiovascular disease. Data were analyzed by use of tract-based spatial statistics, for which the WM skeleton was created, and a permutation-based inference with 5000 permutations was used with a threshold of P < .01, corrected for multiple comparisons to enable identification of abnormalities in fractional anisotropy, mean diffusivity, radial diffusivity, and axial diffusivity.

RESULTS

Tract-based spatial statistics showed decreased fractional anisotropy in multiple areas in patients with primary Sjögren syndrome compared with control subjects, located mainly in the corticospinal tract, superior longitudinal fasciculus, anterior thalamic radiation, inferior fronto-occipital fasciculus, uncinate fasciculus, and inferior longitudinal fasciculus. Increased mean diffusivity and radial diffusivity and decreased axial diffusivity were observed in most of the fiber tracts of the brain in patients with primary Sjögren syndrome, compared with control subjects.

CONCLUSIONS

Patients with primary Sjögren syndrome show loss of WM microstructural integrity, probably related to both Wallerian degeneration and demyelination.

Spontaneous intracranial hemorrhage as an initial manifestation of primary Sjögren's syndrome: a case report

Background

Sjögren’s syndrome can involve the central nervous system; however, spontaneous intracranial hemorrhage has rarely been reported as the initial manifestation.

Case presentation

We report a 39-year-old woman with primary Sjögren’s syndrome presenting with intracranial hemorrhage. The diagnosis of primary Sjögren’s syndrome was based on the presence of ocular dryness, salivary gland secretory and excretory dysfunction confirmed with dynamic tracer emission CT, and positive anti-Sjögren’s syndrome A and anti-Sjögren’s syndrome B antibodies.

Conclusion

Primary Sjögren’s syndrome can present with variable central nervous system signs, which may precede the classic sicca symptoms. Therefore, Sjögren’s syndrome-associated indicators should be investigated in patients without the common risk factors for stroke who present with spontaneous intracranial hemorrhage.

Interactions between developing nerves and salivary glands

Our aim is to provide a summary of the field of salivary gland development and regeneration from the perspective of what is known about the function of nerves during these processes. The primary function of adult salivary glands is to produce and secrete saliva. Neuronal control of adult salivary gland function has been a focus of research ever since Pavlov’s seminal experiments on salivation in dogs. Less is known about salivary gland innervation during development and how the developing nerves influence gland organogenesis and regeneration. Here, we will review what is known about the communication between the autonomic nervous system and the epithelium of the salivary glands during organogenesis. An important emerging theme is the instructive role of the nervous system on the epithelial stem/progenitor cells during development as well as regeneration after damage. We will provide a brief overview of the neuroanatomy of the salivary glands and discuss recent literature that begins to integrate neurobiology with epithelial organogenesis, which may provide paradigms for exploring these interactions in other organ systems.