Citations

AbstractGeniculate neuralgia (GN) is an uncommon, but severe, condition that is characterized by excruciating paroxysmal pain in the seventh cranial nerve's cutaneous distribution of general somatic afferent fibers carried through the nervus intermedius (NI). GN becomes a surgical disease in refractory cases of pain after exhaustive medical management. Surgical intervention in the form of microvascular decompression and nerve sectioning has been investigated with good patient outcomes. Despite this, there are limited guidelines on either technique's appropriateness in specific operative scenarios. In our 30‐year experience in GNs surgical management, we have found that a detailed knowledge of the NIs anatomy, variants, and intraoperative surgical anatomic findings are the key to choosing the most appropriate intervention, and may provide the answer to why some patients fail to experience pain relief after surgery. These anatomic variants also may explain why many patients commonly do not experience side effects related to the visceral efferent and special afferent fibers after nerve sectioning.

ABSTRACTBackground: Dysregulation of the specialized lipid metabolism involved in myelin synthesis and maintenance by oligodendrocytes has been associated with the unique neuropathology of MSA. We hypothesized that apolipoprotein E, which is associated with neurodegeneration, may also play a role in the pathogenesis of MSA.Objective: This study evaluated genetic associations of Apolipoprotein E alleles with risk of MSA and α‐synuclein pathology, and also examined whether apolipoprotein E isoforms differentially affect α‐synuclein uptake in a oligodendrocyte cell.Methods: One hundred sixty‐eight pathologically confirmed MSA patients, 89 clinically diagnosed MSA patients, and 1,277 control subjects were genotyped for Apolipoprotein E. Human oligodendrocyte cell lines were incubated with α‐synuclein and recombinant human apolipoprotein E, with internalized α‐synuclein imaged by confocal microscopy and cells analyzed by flow cytometry.Results: No significant association with risk of MSA or was observed for either Apolipoprotein E ɛ2 or ɛ4. α‐Synuclein burden was also not associated with Apolipoprotein E alleles in the pathologically confirmed patients. Interestingly, in our cell assays, apolipoprotein E ɛ4 significantly reduced α‐synuclein uptake in the oligodendrocytic cell line.Conclusions: Despite differential effects of apolipoprotein E isoforms on α‐synuclein uptake in a human oligodendrocytic cell, we did not observe a significant association at the Apolipoprotein E locus with risk of MSA or α‐synuclein pathology. © 2018 International Parkinson and Movement Disorder Society

ABSTRACTBackgroundThis study aimed to determine the frequency of transactive response DNA binding protein 43 kDa pathology in PSP, the clinical features of patients with this pathology, and genetic risk factors for it.MethodsHippocampal sections were screened with immunohistochemistry for transactive response DNA binding protein 43 kDa in 945 PSP cases. A subset of 261 cases that were negative in hippocampus was screened in the amygdala. The density and disruption of this pathology, as well as regional tau burden, and clinical and genetic characteristics were analyzed.ResultsWe observed transactive response DNA binding protein 43 kDa pathology in 47 cases in the hippocampus and an additional 9 cases that only affected the amygdala. Hippocampal sclerosis was the strongest risk factor, followed by Alzheimer's disease pathology, argyrophilic grain disease, and older age at death. Five stages of transactive response DNA binding protein 43 kDa pathology were identified in PSP: Stage A had pathology only in the amygdala (16%); stage I had pathology confined to the hippocampus and entorhinal cortex (9%); stage II included both regions of stage A and I (38%); stage III spread further to medial occipitotemporal gyrus (20%); and stage IV had pathology in the dorsolateral frontal lobe (18%). Anatomical areas vulnerable to PSP pathology had varying degrees of this pathology in stage II and later. PSP with transactive response DNA binding protein 43 kDa pathology were older at disease onset and had lower median MMSE scores; however, the latter was driven by concurrent pathologies.ConclusionsDistribution and clinical characteristics of transactive response DNA binding protein 43 kDa pathology in PSP were influenced by concurrent pathologies. This is the first study to observe that PSP‐vulnerable regions are also susceptible to this non‐tau pathology. © 2016 International Parkinson and Movement Disorder Society.

ABSTRACTBackgroundThe objectives of this study were to elucidate any potential association between α‐synuclein pathology and cognitive impairment and to determine the profile of cognitive impairment in multiple system atrophy (MSA) patients. To do this, we analyzed the clinical and pathologic features in autopsy‐confirmed MSA patients.MethodsWe retrospectively reviewed medical records, including neuropsychological test data, in 102 patients with autopsy‐confirmed MSA in the Mayo Clinic brain bank. The burden of glial cytoplasmic inclusions and neuronal cytoplasmic inclusions were semiquantitatively scored in the limbic regions and middle frontal gyrus. We also assessed concurrent pathologies potentially causing dementia including Alzheimer's disease, hippocampal sclerosis, and cerebrovascular pathology.ResultsOf 102 patients, 33 (32%) were documented to have cognitive impairment. Those that received objective testing, deficits primarily in processing speed and attention/executive functions were identified, which suggests a frontal‐subcortical pattern of dysfunction. Of these 33 patients with cognitive impairment, 8 patients had concurrent pathologies of dementia. MSA patients with cognitive impairment had a greater burden of neuronal cytoplasmic inclusions in the dentate gyrus than patients without cognitive impairment, both including and excluding patients with concurrent pathologies of dementia.ConclusionsThe cognitive deficits observed in this study were more evident on neuropsychological assessment than with cognitive screens. Based on these findings, we recommend that clinicians consider more in‐depth neuropsychological assessments if patients with MSA present with cognitive complaints. Although we did not identify the correlation between cognitive deficits and responsible neuroanatomical regions, a greater burden of neuronal cytoplasmic inclusions in the limbic regions was associated with cognitive impairment in MSA. © 2016 International Parkinson and Movement Disorder Society

ABSTRACTBackgroundCerebellar ataxia is an exclusion criterion for the clinical diagnosis of progressive supranuclear palsy, but a variant with predominant cerebellar ataxia has been reported. The aims of this study were to estimate the frequency of progressive supranuclear palsy with predominant cerebellar ataxia in an autopsy series from the United States and to compare clinical, pathologic, and genetic differences between progressive supranuclear palsy with and without predominant cerebellar ataxia.MethodWe selected 100 consecutive patients with pathologically confirmed progressive supranuclear palsy who had been evaluated at the Mayo Clinic (referred to as the Mayo Clinic patient series) from our brain bank database (N = 1085). We next enriched in cases likely to have cerebellar ataxia by searching the remaining 985 cases for (1) an antemortem diagnosis of multiple system atrophy or (2) neuropathologic evidence of prominent degeneration of the cerebellum or cerebellar afferent nuclei. Subsequently, clinical, pathologic, and genetic features were compared between the two groups.ResultsOne patient in the Mayo Clinic patient series (1%) met criteria for progressive supranuclear palsy with predominant cerebellar ataxia and had both cerebellar and mild midbrain atrophy on MRI. Four patients were identified with the targeted search. Four of the five patients were clinically misdiagnosed as multiple system atrophy. The severity of tau‐related pathology and cerebellar degeneration were not different between the two groups. No differences were detected in tau genotypes.ConclusionAlthough our data cannot provide definitive information about how to make an accurate clinical diagnosis, they should serve to raise awareness of progressive supranuclear palsy with predominant cerebellar ataxia in the differential diagnosis of multiple system atrophy. © 2016 Movement Disorder Society