Intraneural ganglion cysts of the lower limb. / Intraneurale Ganglionzysten der unteren Extremität.

BACKGROUND: Intraneural ganglion cysts are rare. They affect the peripheral nerves. According to the most widely accepted theory (articular/synovial theory), the cysts are formed from a capsular defect of an adjacent joint, so that synovial fluid spreads along the epineurium of a nerve branch. This leads to diverse neurological symptoms. We will illustrate this disease based on three of our own cases. METHODS: Patients were examined between 2011 and 2018 using lower limb MRI. MRI scans were also performed for the follow-up examinations. CASE STUDIES AND DISCUSSION: The patients had many symptoms. We were able to accurately detect the intraneural ganglion cysts on MRI and provide the treating surgeons with the basis for the operation to be performed. The success of surgical therapy depends on the resection of the nerve endings supplying the joint as the only way to treat the origin of the disease and prevent recurrence. Based on our case studies, we can support the commonly favored articular/synovial theory. KEY POINTS: · Intraneural ganglion cysts can cause diverse neurological symptoms depending on their location.. · The pathogenesis is reasonably explained by the articular/synovial theory, which states that cysts are the result of a capsular defect of a joint.. · MRI is the method of choice for diagnosing intraneural ganglion cysts. However, ultrasound is also important.. · Surgery is the only curative treatment with treatment success being dependent on ligature of the nerve endings supplying the articular branch.. CITATION FORMAT: · Fricke T, Schmitt AD, Jansen O. Intraneural ganglion cysts of the lower limb. Fortschr Röntgenstr 2019; 191: 732 - 738.

Alpha-synuclein is associated with the synaptic vesicle apparatus in the human and rat enteric nervous system.

BACKGROUND AND AIMS: Aggregation of alpha-synuclein (a-syn) has been implicated in the development of neurodegenerative diseases including its spread from the enteric nervous system (ENS) to the brain. Physiologically, a-syn is located at the presynapse and might be involved in regulating of neurotransmission. Therefore, the aim of the study was to characterize the physiological ontogenetic and locoregional expression pattern of a-syn in the ENS and its association with the synaptic vesicle apparatus. MATERIAL AND METHODS: Ontogenetic mRNA expression of a-syn and synaptophysin was determined in the rat intestine. Myenteric plexus cultures treated with glial cell line-derived neurotrophic factor (GDNF) were assessed for mRNA expression of a-syn, co-localization of a-syn with the pan-neuronal marker PGP 9.5 and the synaptic vesicle marker synaptophysin and studied by scanning electron microscopy (SEM). Human colonic specimens were subjected to co-localization studies of a-syn with synaptophysin. RESULTS: a-syn and synaptophysin intestinal gene expression levels were highest during early postnatal life and also detectable at adult age. a-syn was co-localized with PGP 9.5 and synaptophysin in myenteric plexus cultures and up-regulated after GDNF treatment. SEM confirmed the presence of neuronal varicosities to which a-syn was associated. Consistently, a-syn and synaptophysin showed partial co-localization in the human ENS. CONCLUSIONS: The ontogenetic and cellular expression pattern as well as the regulation by GNDF give evidence that a-syn is physiologically associated to the synaptic vesicle apparatus. The data suggest that a-syn is involved in the regulation of synaptic plasticity in the ENS during early postnatal life and adult age.

Expression pattern and localization of alpha-synuclein in the human enteric nervous system.

BACKGROUND: Alpha-synuclein (α-syn) is abundantly expressed in the central nervous system and involved in the regulation of neurotransmission. Insoluble fibrils of phosphorylated α-synuclein (p-α-syn) have been implicated in several neurodegenerative diseases (e.g. Parkinson's disease, Alzheimer's disease). The aim of the study was to determine the gene expression pattern and localization of α-syn/p-α-syn in the human enteric nervous system (ENS). METHODS: Human colonic specimens (n=13, 15-83 years) were processed for α-syn and p-α-syn immunohistochemistry. Colocalization of α-syn was assessed by dual-labeling with pan-neuronal markers (PGP 9.5, HuC/D). For qPCR studies, tissue was obtained from full-thickness sections, tunica muscularis, submucosa, mucosa, and laser-microdissected (LMD) enteric ganglia. RESULTS: Highest α-syn levels were detectable within the tunica muscularis and submucosa. Ganglia isolated by LMD showed high expression of α-syn mRNA. All myenteric and submucosal ganglia and nerve fibers were immunoreactive for α-syn. Dual-labeling revealed colocalization of α-syn with both pan-neuronal markers. p-α-syn immunoreactivity was consistently observed in specimens from adults with increasing age. CONCLUSIONS: α-syn is abundantly expressed in all nerve plexus of the human ENS including both neuronal somata and processes. The presence of p-α-syn within the ENS is a regular finding in adults with increasing age and may not be regarded as pathological correlate. The data provide a basis to unravel the functions of α-syn and to evaluate altered α-syn in enteric neuropathies and α-synucleinopathies of the CNS with gastrointestinal manifestations.