Ultrasound-guided alcoholization demonstrated a safe profile, relieved neuropathic symptoms in a majority of patients and improved their quality of life. Rescue therapy with surgery is feasible in patients with unsatisfactory response. However, a thorough evaluation for forefoot comorbidities should be obtained, as they may act as confounding factors.

In patients with suspected dementia with Lewy bodies the detection of the disease-associated α-synuclein in easily accessible tissues amenable to be collected using minimally invasive procedures, remains a major diagnostic challenge. This approach has the potential to take advantage of modern molecular assays for the diagnosis of α–synucleinopathy and, in turn, to optimize the recruitment and selection of patients in clinical trials, using drugs directed at counteracting α-synuclein aggregation. In this study, we explored the diagnostic accuracy of α-synuclein real-time quaking-induced conversion assay by testing olfactory mucosa and CSF in patients with a clinical diagnosis of probable (n = 32) or prodromal (n = 5) dementia with Lewy bodies or mixed degenerative dementia (dementia with Lewy bodies/Alzheimer’s disease) (n = 6). Thirty-eight patients with non-α-synuclein-related neurodegenerative and non-neurodegenerative disorders, including Alzheimer’s disease (n = 10), sporadic Creutzfeldt-Jakob disease (n = 10), progressive supranuclear palsy (n = 8), corticobasal syndrome (n = 1), fronto-temporal dementia (n = 3) and other neurological conditions (n = 6) were also included, as controls. All 81 patients underwent olfactory swabbing while CSF was obtained in 48 participants. At the initial blinded screening of olfactory mucosa samples, 38 out of 81 resulted positive while CSF was positive in 19 samples out of 48 analyzed. After unblinding of the results, 27 positive olfactory mucosa were assigned to patients with probable dementia with Lewy bodies, five with prodromal dementia with Lewy bodies and three to patients with mixed dementia, as opposed to three out 38 controls. Corresponding results of CSF testing disclosed 10 out 10 positive samples in patients with probable dementia with Lewy bodies and six out of six with mixed dementia, in addition to three out of 32 for controls. The accuracy among results of real-time quaking-induced conversion assays and clinical diagnoses was 86.4% in the case of olfactory mucosa and 93.8% for CSF. For the first time, we showed that α-synuclein real-time quaking induced conversion assay detects α-synuclein aggregates in olfactory mucosa of patients with dementia with Lewy bodies and with mixed dementia. Additionally, we provided preliminary evidence that the combined testing of olfactory mucosa and CSF raised the concordance with clinical diagnosis potentially to 100%. Our results suggest that nasal swabbing might be considered as a first line screening procedure in patients with a diagnosis of suspected dementia with Lewy bodies followed by CSF analysis, as a confirmatory test, when the result in the olfactory mucosa is incongruent with the initial clinical diagnosis.

Pathological evidence of amyloid on nerve biopsy has been the gold standard for diagnosis in hereditary transthyretin amyloidosis polyneuropathy (hATTR-PN) for a long time. In this article, we reviewed the pathological findings of a large series of sural nerve biopsies from a cohort of hATTR-PN patients, collected by different Italian referral centers. Patients and Methods: We reviewed clinical and pathological data from hATTR-PN patients, diagnosed and followed in five Italian referral centers for peripheral neuropathies. Diagnosis was formulated after a positive genetic test for transthyretin (TTR) mutations. Sural nerve biopsy was performed according to standard protocols. Results: Sixty-nine sural nerve biopsies from hATTR-PN patients were examined. Congo red positive deposits were found in 73% of cases. Only the Phe64Leu mutation failed to show amyloid deposits in a high percentage of biopsies (54%), as already described. Unusual pathological findings, such as myelin abnormalities or inflammatory infiltrates, were detected in occasional cases. Conclusions: Even if no longer indicated to confirm hATTR-PN clinical suspicion, nerve biopsy remains, in expert hands, a rapid and inexpensive tool to detect amyloid deposition. In Italy, clinicians should be aware that a negative biopsy does not exclude hATTR-PN, particularly for Phe64Leu, one of the most frequent mutations in this country.

No abstract

A novel neuronal tauopathy, mainly confined to hypothalamus and brainstem tegmentum, has recently been reported in patients with autoantibodies to the neuronal cell-adhesion molecule IgLON5. We describe a patient with anti-IgLON5 syndrome, who presented with dysautonomia and sleep disorder, followed by subacute dementia. Postmortem brain examination disclosed neuronal tau pathology prevailing in the hippocampus, amygdala, and locus coeruleus, in addition to microglial/neuronal TDP-43 pathology, with overexpression of aberrantly phosphorylated forms and neurotoxic truncated fragments, in basal ganglia, nucleus basalis, thalamus, and midbrain. These findings suggest that neurodegeneration in anti-IgLON5 syndrome might also occur via a microglia-triggered non-cell autonomous pathway.

Background A biallelic intronic AAGGG repeat expansion in the Replication Factor C subunit 1 (RFC1) gene has been recently associated with Cerebellar Ataxia, Neuropathy, Vestibular Areflexia Syndrome, a disorder often presenting as a slowly evolving sensory neuropathy at the onset. “Chronic Idiopathic Axonal Polyneuropathy” (CIAP) is a common indolent axonal neuropathy of adulthood which remains without an identifiable cause despite thorough investigations. Methods We screened 234 probands diagnosed with CIAP for a pathogenic biallelic RFC1 AAGGG repeat expansion. Patients were selected from 594 consecutive patients with neuropathy referred to our tertiary-care center for a sural nerve biopsy over 10 years. Results The RFC1 AAGGG repeat expansion was common in patients with pure sensory neuropathy (21/40, 53%) and less frequent in cases with predominantly sensory (10/56, 18%, P < 0.001) or sensorimotor (3/138, 2%, P < 0.001) neuropathy. The mutation was associated with sensory ataxia (τb = 0.254, P < 0.001), autonomic disturbances (35% vs 8%, Prevalence Odds Ratio—POR 6.73 CI 95% 2.79–16.2, P < 0.001), retained deep tendon reflexes (score 18.0/24 vs 11.5/24, R = 0.275, P < 0.001). On pathology, we observed absent/scant regenerative changes (τb = − 0.362, P < 0.001), concomitant involvement of large (100% and 99%, n.s.), small myelinated (97% vs 81%, POR 7.74 CI 95% 1.03–58.4, P = 0.02) and unmyelinated nerve fibers (85% vs 41%, POR 8.52 CI 95% 3.17–22.9, P < 0.001). Cerebellar or vestibular involvement was similarly rare in the two groups. Conclusions This study highlights the frequent occurrence of the RFC1 AAGGG repeat expansion in patients diagnosed with CIAP and characterizes the clinical and pathological features of the related neuro(no)pathy.

This simplified callosal angle measure represents an accurate, reproducible, and easy marker of iNPH.

Background In patients with Parkinson’s disease (PD), real-time quaking-induced conversion (RT-QuIC) detection of pathological α-synuclein (α-syn) in olfactory mucosa (OM) is not as accurate as in other α-synucleinopathies. It is unknown whether these variable results might be related to a different distribution of pathological α-syn in OM. Thus, we investigated whether nasal swab (NS) performed in areas with a different coverage by olfactory neuroepithelium, such as agger nasi (AN) and middle turbinate (MT), might affect the detection of pathological α-syn. Methods NS was performed in 66 patients with PD and 29 non-PD between September 2018 and April 2021. In 43 patients, cerebrospinal fluid (CSF) was also obtained and all samples were analyzed by RT-QuIC for α-syn. Results In the first round, 72 OM samples were collected by NS, from AN (NSAN) or from MT (NSMT), and 35 resulted positive for α-syn RT-QuIC, including 27/32 (84%) from AN, 5/11 (45%) from MT, and 3/29 (10%) belonging to the non-PD patients. Furthermore, 23 additional PD patients underwent NS at both AN and MT, and RT-QuIC revealed α-syn positive in 18/23 (78%) NSAN samples and in 10/23 (44%) NSMT samples. Immunocytochemistry of NS preparations showed a higher representation of olfactory neural cells in NSAN compared to NSMT. We also observed α-syn and phospho-α-syn deposits in NS from PD patients but not in controls. Finally, RT-QuIC was positive in 22/24 CSF samples from PD patients (92%) and in 1/19 non-PD. Conclusion In PD patients, RT-QuIC sensitivity is significantly increased (from 45% to 84%) when NS is performed at AN, indicating that α-syn aggregates are preferentially detected in olfactory areas with higher concentration of olfactory neurons. Although RT-QuIC analysis of CSF showed a higher diagnostic accuracy compared to NS, due to the non-invasiveness, NS might be considered as an ancillary procedure for PD diagnosis.