The pattern and diagnostic criteria of sensory neuronopathy: a case-control study

Abstract

Acquired sensory neuronopathies encompass a group of paraneoplastic, dysimmune, toxic or idiopathic disorders characterized by degeneration of peripheral sensory neurons in dorsal root ganglia. As dorsal root ganglia cannot easily be explored, the clinical diagnosis of these disorders may be difficult. The question as to whether there exists a common clinical pattern of sensory neuronopathies, allowing the establishment of validated and easy-to-use diagnostic criteria, has not yet been addressed. In this study, logistic regression was used to construct diagnostic criteria on a retrospective study population of 78 patients with sensory neuronopathies and 56 with other sensory neuropathies. For this, sensory neuronopathy was provisionally considered as unambiguous in 44 patients with paraneoplastic disorder or cisplatin treatment and likely in 34 with a dysimmune or idiopathic setting who may theoretically have another form of neuropathy. To test the homogeneity of the sensory neuronopathy population, likely candidates were compared with unambiguous cases and then the whole population was compared with the other sensory neuropathies population. Criteria accuracy was checked on 37 prospective patients referred for diagnosis of sensory neuropathy. In the study population, sensory neuronopathy showed a common clinical and electrophysiological pattern that was independent of the underlying cause, including unusual forms with only patchy sensory loss, mild electrical motor nerve abnormalities and predominant small fibre or isolated lower limb involvement. Logistic regression allowed the construction of a set of criteria that gave fair results with the following combination: ataxia in the lower or upper limbs + asymmetrical distribution + sensory loss not restricted to the lower limbs + at least one sensory action potential absent or three sensory action potentials <30% of the lower limit of normal in the upper limbs + less than two nerves with abnormal motor nerve conduction study in the lower limbs.

Rapid neurophysiological screening for sensory ganglionopathy: A novel approach

“…The asymmetry in the neurophysiological findings is not included in the published diagnostic criteria (Camdessanché et al., 2009), but the criteria only include the clinical asymmetric sensory deficits.A diagnosis of SG can still be made even in the absence of values below normal limits, as the diagnosis is based on the number asymmetries (often patients with SG at early stages present with asymmetric SNAPs, which are still within normal limits). …”

“…The asymmetry in the neurophysiological findings is not included in the published diagnostic criteria (Camdessanché et al., 2009), but the criteria only include the clinical asymmetric sensory deficits.…”

Ulnar sensory-motor amplitude ratio: a new tool to differentiate ganglionopathy from polyneuropathy

“…Camdessanché et al investigated whether SNAP amplitudes of the median, ulnar, radial, sural and superficial peroneal nerves would individually enable the distinction between GNP and PNP 3 . They found that nerves in the upper limbs are significantly more compromised in GNP, but using different thresholds to separate GNP and PNP sensitivity and specificity values ranged between 70 and 85% 3 .…”

“…They found that nerves in the upper limbs are significantly more compromised in GNP, but using different thresholds to separate GNP and PNP sensitivity and specificity values ranged between 70 and 85% 3 . This motivated us to investigate other parameters derived from NCS that might work better.…”

Transglutaminase 6 antibodies in gluten neuropathy

“…Patients were diagnosed with sensory ganglionopathy when only sensory fibers were affected in an asymmetrical fashion or where no sensory responses were elicited by any sensory nerve with motor responses being normal [11]. Finally, patients with involvement of sensory and motor fibers of specific nerves, sparing others, were diagnosed with mononeuritis multiplex.…”