Peripheral neuropathy occurs in Sjögren's syndrome, a disorder in which systemic immunologic phenomena, including vasculitis, are common. Neuropathy also occurs with isolated sicca complex (keratoconjunctivits sicca and xerostomia); whether this represents a distinct syndrome is unclear. We retrospectively studied 54 patients with sicca complex and peripheral neuropathy to determine mode of presentation, neuropathic patterns, frequency and pattern of serologic abnormalities, and frequency of systemic disease, including necrotizing vasculitis. Peripheral neuropathy was the presenting problem in 87%. Although sicca symptoms occurred in 93%, they were a presenting complaint in only 11% and were usually mild, reported only after specific inquiry. Minor salivary gland biopsy was positive in 73%. Sensory neuropathies strongly predominated; 61% of patients manifested either sensory polyneuropathy or polyganglionopathy. Less common patterns included sensorimotor polyneuropathy (17%) and polyradiculoneuropathy (11%). Vasculitic neuropathy was demonstrated in only two patients, but nonspecific epineurial inflammation was present in 70% of nerve biopsies. Clinical evidence of systemic disease was uncommon, particularly in the sensory polyganglionopathy group, in whom extraglandular features other than weight loss occurred in only 1 of 12 patients. Antibodies to extractable nuclear antigens, the most specific serologic marker of Sjögren's syndrome, were present in 10.4%. We conclude that peripheral neuropathy and isolated sicca complex form a distinctive syndrome in which neuropathy is the presenting feature and sicca is easily overlooked; sensory polyneuropathy and polyganglionopathy predominate; serology is confirmatory but very insensitive; and extraglandular disease, including vasculitis, is uncommon compared with typical Sjögren's syndrome. Tests of ocular or salivary involvement are needed for diagnosis, and demonstration of inflammation in biopsied nerve is supportive. Improved definition of this disorder should permit further studies of natural history and efficacy of immunotherapy.

The evolution of particle image velocimetry (PIV) from its various roots is discussed. The importance of these roots and their influence on different trends in the speciality are described. The state-of-the-art of the technique today is overviewed and illustrated by reference to recent, seminal publications describing both the development and application of PIV.

ObjectiveLong-term follow-up of population-based prospective studies is often achieved through linkages to coded regional or national health care data. Our knowledge of the accuracy of such data is incomplete. To inform methods for identifying stroke cases in UK Biobank (a prospective study of 503,000 UK adults recruited in middle-age), we systematically evaluated the accuracy of these data for stroke and its main pathological types (ischaemic stroke, intracerebral haemorrhage, subarachnoid haemorrhage), determining the optimum codes for case identification.MethodsWe sought studies published from 1990-November 2013, which compared coded data from death certificates, hospital admissions or primary care with a reference standard for stroke or its pathological types. We extracted information on a range of study characteristics and assessed study quality with the Quality Assessment of Diagnostic Studies tool (QUADAS-2). To assess accuracy, we extracted data on positive predictive values (PPV) and—where available—on sensitivity, specificity, and negative predictive values (NPV).Results37 of 39 eligible studies assessed accuracy of International Classification of Diseases (ICD)-coded hospital or death certificate data. They varied widely in their settings, methods, reporting, quality, and in the choice and accuracy of codes. Although PPVs for stroke and its pathological types ranged from 6–97%, appropriately selected, stroke-specific codes (rather than broad cerebrovascular codes) consistently produced PPVs >70%, and in several studies >90%. The few studies with data on sensitivity, specificity and NPV showed higher sensitivity of hospital versus death certificate data for stroke, with specificity and NPV consistently >96%. Few studies assessed either primary care data or combinations of data sources.ConclusionsParticular stroke-specific codes can yield high PPVs (>90%) for stroke/stroke types. Inclusion of primary care data and combining data sources should improve accuracy in large epidemiological studies, but there is limited published information about these strategies.

The pathologic changes of nerves in multifocal motor neuropathy (MMN), a rare neuropathy with selective focal conduction block of motor fibers in mixed nerves, remain essentially unstudied. Fascicular nerve biopsy of 8 forearm or arm nerves in 7 patients with typical MMN was undertaken for diagnostic reasons at the site of the conduction block. Abnormalities were seen in 7 of 8 nerves, including a varying degree of multifocal fiber degeneration and loss, an altered fiber size distribution with fewer large fibers, an increased frequency of remyelinated fiber profiles, and frequent and prominent regenerating fiber clusters. Small epineurial perivascular inflammatory infiltrates were observed in 2 nerves. We did not observe overt segmental demyelination or onion bulb formation. We hypothesize that an antibody-mediated attack directed against components of axolemma at nodes of Ranvier could cause conduction block, transitory paranodal demyelination and remyelination, and axonal degeneration and regeneration. Alternatively, the antibody attack could be directed at components of paranodal myelin. We favor the first hypothesis because in nerves studied by us, axonal pathological alteration predominated over myelin pathology. Irrespective of which mechanism is involved, we conclude that the unequivocal multifocal fiber degeneration and loss and regenerative clusters at sites of conduction block explains the observed clinical muscle weakness and atrophy and alterations of motor unit potentials. The occurrence of conduction block and multifocal fiber degeneration and regeneration at the same sites suggests that the processes of conduction block and fiber degeneration and regeneration are linked. Finding discrete multifocal fiber degeneration may also provide an explanation for why the functional abnormalities remain unchanged over long periods of time at discrete proximal to distal levels of nerve and may emphasize a need for early intervention (assuming that efficacious treatment is available).

This publication is based upon work from COST Action CA18218 (European Burden of disease Network-www.