B Dyck, P James

ABSTRACTIntroductionSjögren syndrome is thought to be a lymphocyte‐driven process. Peripheral nervous system involvement occurs in about 20%–25% of patients. A sensory‐predominant, large‐fiber peripheral neuropathy is most common, and it is usually associated with a subacute to chronic presentation.MethodsWe report a rare case of an acute Sjögren‐associated, sensory predominant, length‐dependent peripheral neuropathy mimicking Guillain–Barré syndrome. The patient presented with sensory ataxia preceded by fever and polyarthralgia. She gave a history of years of dry eyes and dry mouth.ResultsShe had a positive Shirmer test, abnormal salivary gland scan, and positive SS‐A and SS‐B antibodies. A sural nerve biopsy showed an unusual, dense, non‐IgG4, polyclonal, plasma‐cell perivascular infiltrate. The patient responded to treatment with weekly pulse intravenous methylprednisolone.ConclusionsSjögren syndrome can present with acute‐onset, sensory predominant peripheral neuropathy. The role of plasma cells in Sjögren syndrome is unexplored and deserves further study. Muscle Nerve 55: 605–608, 2017

ObjectiveTo systematically compare transthyretin with primary amyloid neuropathy to define their natural history and the underlying mechanisms for differences in phenotype and natural history.MethodsAll patients with defined amyloid subtype and peripheral neuropathy who completed autonomic testing and electromyography at Mayo Clinic Rochester between 1993 and 2013 were included. Medical records were reviewed for time of onset of defined clinical features. The degree of autonomic impairment was quantified using the composite autonomic severity scale. Comparisons were made between acquired and inherited forms of amyloidosis.ResultsOne hundred one cases of amyloidosis with peripheral neuropathy were identified, 60 primary and 41 transthyretin. Twenty transthyretin cases were found to have Val30Met mutations; 21 had other mutations. Compared to primary cases, transthyretin cases had longer survival, longer time to diagnosis, higher composite autonomic severity scale scores, greater reduction of upper limb nerve conduction study amplitudes, more frequent occurrence of weakness, and later non‐neuronal systemic involvement. Four systemic markers (cardiac involvement by echocardiogram, weight loss > 10 pounds, orthostatic intolerance, fatigue) in combination were highly predictive of poor survival in both groups.InterpretationThese findings suggest that transthyretin has earlier and greater predilection for neural involvement and more delayed systemic involvement. The degree and rate of systemic involvement is most closely related to prognosis. Ann Neurol 2016;80:401–411