Neuroimaging Markers for Differential Diagnosis Between Multifocal Motor Neuropathy and Multifocal Acquired Demyelinating Sensory and Motor Neuropathy

Introduction. Similar asymmetric patterns of motor disorders and neurophysiological changes complicate the differential diagnosis between multifocal motor neuropathy (MMN) and multifocal acquired demyelinating sensory and motor neuropathy (MADSAM) as two chronic dysimmune neuropathies with significantly different treatment approaches. The lack of specific paraclinical markers often result in misdiagnosis and selection of ineffective specific therapy. Identification of specific neuroimaging biomarkers to differentiate these conditions may improve diagnostic approaches. Objective: To identify neuroimaging markers for the differential diagnosis between MMN and MADSAM. Materials and methods. The study included 65 participants, particularly 30 individuals with MMN and 35 individuals with MADSAM followed up in the Center of Peripheral Nervous System Diseases, Research Center of Neurology, Moscow, Russia. We retrospectively analyzed their clinical and epidemiological characteristics as well as ultrasonography and magnetic resonance imaging (MRI) findings. Results. Ultrasonography was performed on the peripheral nerves of the upper extremities, the spinal nerves, and the brachial plexus. The results showed that participants with MADSAM had significantly greater cross-sectional areas (CSAs) and a higher incidence of intraneural ultrasonographic abnormalities compared to participants with MMN. CSA thresholds of the median nerves were identified using ROC analysis to differentiate between MMN and MADSAM. MRI scans of the brachial plexus revealed no abnormalities in 41.4% of the individuals with MMN and 27.3% of the individuals with MADSAM. Meanwhile, STIR hyperintense signal from the brachial plexus was most typical ( 70%) for the MADSAM group. Conclusions. This was the first detailed comparative analysis of neuroimaging findings in a large sample of patients with either MMN or MADSAM in Russia. Ultrasonographic markers for differential diagnosis have been determined. The advantages and limitations of ultrasonography and MRI of the brachial plexus and the spinal and peripheral nerves in diagnosing multifocal chronic dysimmune neuropathies have been demonstrated

Salivary gland immunohistochemistry vs substantia nigra sonography: comparative analysis of diagnostic significance

Introduction. Parkinson's disease (PD) urges for new instrumental methods of diagnosis. Transcranial sonography of the substantia nigra (SN TCS) is an established method for early PD diagnosis but its application is limited. Recently, biopsies (primarily that of salivary gland) and test for abnormal -synuclein are suggested to verify PD. Materials and methods. We assessed 12 individuals with PD, HoehnYahr 2.3 0.4. The assessments included: UPDRS, NMSQ, NMSS, RBDSQ, PDQ-8, MoCA, and HADS scoring; SN TCS; and sublingual gland immunohistochemistry for phosphorylated -synuclein (PS-129) with automated morphometric analysis. Results. Substantia nigra hyperechogenicity was shown in 75% of patients whereas biopsy revealed PS-129 in 100% of patients. Echogenic area of the substantia nigra was 0.24 [0.21; 0.3] cm2. PS-129 inclusion area varied from 28.47 [27.55; 96.26] to 238.77 [234.13; 272.49] m2, and PS-129 proportion varied from 13.4% to 93.4% of the nervous fiber area across the patients. We found relations between PS-129 and NMSQ (r = 0.8; p 0.001), NMSS (r = 0.9; p 0.001), PDQ-8 (r = 0.7; p = 0.003), UPDRS-I (r = 0.7; p = 0.009), UPDRS-II (r = 0.6; p = 0.03), and HADS (anxiety r = 0.8; p = 0.002; depression r = 0.6; p = 0.04) scores. Conclusion. The results demonstrate a higher biopsy sensitivity as compared to SN TCS. Automated morphometric analysis has been newly applied to assess PS-129 occurrence. Immunohistochemistry results are directly related to non-motor symptom severity, which may indicate high probability of PS-129 presence and diagnosis confirmation in early disease

Conventional magnetic resonance imaging of peripheral nerves: MR-neurography

Peripheral neuropathy is known to be one of the most common neurological disorders. Despite the great diagnostic value of electroneuromyography and ultrasound, addressing the diagnostics and differential diagnostics of peripheral nerve diseases of different origin could be challenging. In recent years, magnetic resonance tomography has been increasingly used for evaluating cases of suspected or established peripheral neuropathy with excellent results. This manuscript mainly deals with the advantages and limitations of the aforementioned diagnostic instruments, technical considerations according to different anatomy of peripheral nerves, along with state-of-the-art technical decisions, frequently used magnetic resonance imaging sequences and their diagnostic value based on own observation, and recommendations for contrast enhancement use and different methods of fat suppression. Currently, there is practically no standardized description of normal magnetic resonance imaging features of peripheral nerves, as well as their changes in different diseases. The evaluation of images is mainly based on the radiologist experience, which obviously decreases method’s diagnostic value. Studies of large numbers involving healthy volunteers and patients with peripheral neuropathies of different origin are required to address this issue