Lower extremity vasospasm associated with ischemic neuropathy, dermal fibrosis, and digital gangrene in a patient with carcinoid syndrome

Structural Nerve Remodeling at 3-T MR Neurography Differs between Painful and Painless Diabetic Polyneuropathy in Type 1 or 2 Diabetes

Background The pathophysiologic mechanisms underlying painful symptoms in diabetic polyneuropathy (DPN) are poorly understood. They may be associated with MRI characteristics, which have not yet been investigated. Purpose To investigate correlations between nerve structure, load and spatial distribution of nerve lesions, and pain in patients with DPN. Materials and Methods In this prospective single-center cross-sectional study, participants with type 1 or 2 diabetes volunteered between June 2015 and March 2018. Participants underwent 3-T MR neurography of the sciatic nerve with a T2-weighed fat-suppressed sequence, which was preceded by clinical and electrophysiologic tests. For group comparisons, analysis of variance or the Kruskal-Wallis test was performed depending on Gaussian or non-Gaussian distribution of data. Spearman correlation coefficients were calculated for correlation analysis. Results A total of 131 participants (mean age, 62 years ± 11 [standard deviation]; 82 men) with either type 1 (n = 45) or type 2 (n = 86) diabetes were evaluated with painful (n = 64), painless (n = 37), or no (n = 30) DPN. Participants who had painful diabetic neuropathy had a higher percentage of nerve lesions in the full nerve volume (15.2% ± 1.6) than did participants with nonpainful DPN (10.4% ± 1.7, P = .03) or no DPN (8.3% ± 1.7; P < .001). The amount and extension of T2-weighted hyperintense nerve lesions correlated positively with the neuropathy disability score (r = 0.37; 95% confidence interval [CI]: 0.21, 0.52; r = 0.37; 95% CI: 0.20, 0.52, respectively) and the neuropathy symptom score (r = 0.41; 95% CI: 0.25, 0.55; r = 0.34; 95% CI: 0.17, 0.49, respectively). Negative correlations were found for the tibial nerve conduction velocity (r = -0.23; 95% CI: -0.44, -0.01; r = -0.37; 95% CI: -0.55, -0.15, respectively). The cross-sectional area of the nerve was positively correlated with the neuropathy disability score (r = 0.23; 95% CI: 0.03, 0.36). Negative correlations were found for the tibial nerve conduction velocity (r = -0.24; 95% CI: -0.45, -0.01). Conclusion The amount and extension of T2-weighted hyperintense fascicular nerve lesions were greater in patients with painful diabetic neuropathy than in those with painless diabetic neuropathy. These results suggest that proximal fascicular damage is associated with the evolution of painful sensory symptoms in diabetic polyneuropathy. © RSNA, 2019 Online supplemental material is available for this article.

Complications from carcinoid syndrome: review of the current evidence

Patients with well-differentiated neuroendocrine tumours may develop carcinoid syndrome (CS), which is characterised by flushing, abdominal cramps, diarrhoea, and bronchospasms. In this scenario, long-term secretion of vasoactive substances—serotonin, tachynins, and others, may induce fibrogenic responses in local or distant tissues, leading to complications such as carcinoid heart disease (CHD), mesenteric and/or retroperitoneal fibrosis. Rare cases of lung/pleural fibrosis and scleroderma have also been described. Despite it not being well described yet, current evidence suggests the pathogenesis of such fibrogenic complications relies on signalling through 5-HT_2B and TGF-β1. Medical management is still very limited and lacks prospective and randomised studies for definitive recommendations. Surgical procedures remain the best definitive treatment option for CHD and abdominal fibrosis. Recently, cognitive impairment has also been described as a potential consequence of CS. This review critically discusses the literature concerning the epidemiology, pathogenesis, clinical features, diagnosis, and treatment options for CS-related long-term complications.

Primary lung carcinoid, a rare cause of paraparesis: report of a case and review of the literature

Carcinoids are neuroendocrine tumors mainly involving the gastrointestinal tract, lungs and bronchi. They were considered benign with slow growth, but they can be malignant in a substantial percentage of patients (metastasizing to liver, bones, skin, etc). Endocrine activity results in carcinoid syndrome. Proximal myopathy has been reported in 7% of patients with carcinoid syndrome. Bronchopulmonary and thymic carcinoids producing adrenocorticotropic hormone can cause Cushing's syndrome, a main feature of which is myopathy. There are a few reports of carcinoids associated with paraneoplastic neurological syndromes, including neuropathy. We hereby present an extremely rare case of a primary lung carcinoid presented with paraparesis due to polyneuropathy, and review the relevant literature. To the best of our knowledge there is no similar previous report. Complete resolution of paraparesis after excision of the lung carcinoid suggests paraneoplastic neurological syndrome.

Fibrosis and carcinoid syndrome: from causation to future therapy

Carcinoid tumors are part of a heterogeneous group of gastrointestinal and pancreatic endocrine tumors that are characterized by their capacity to produce and secrete hormones, 5-hydroxytryptamine, tachykinins and other mediators. These substances are thought to be responsible for the collection of symptoms, which include diarrhea, flushing and wheezing, that is known as carcinoid syndrome. Fibrosis that occurs either local to or distant from the primary tumor is one of the hallmarks of carcinoid tumors that originate from the midgut. The fibrotic process can occur in the mesentery as a desmoplastic response and may lead to obstruction of the small bowel, but it can also occur in the lungs, skin or retroperitoneum. Importantly, up to one-third of patients develop cardiac valvulopathy. One or more products that are secreted by the tumor and enter into the circulation are likely to have a role in this process. This Review discusses the incidence and prevalence of fibrosis in carcinoid syndrome and explores evidence to date for causative agents, in particular the roles of 5-hydroxytryptamine and elements of the downstream signaling pathway. Improved understanding of the etiology of carcinoid-tumor-related fibrosis may lead to better treatments for this condition than those we currently have.

Alteration in cardiovascular function and body surface temperature during percutaneous stereotactic upper thoracic ganglionectomy and sympathectomy in palmar hyperhidrotic patients

We assessed changes in cardiovascular function, specifically arterial blood pressure and heart rate in 6 palmar hyperhidrotic patients before, during, and after T2 and T3 ganglionectomy and sympathectomy. We also assessed changes in skin temperature, specifically at the forehead, axilla, thumb, loin, and sole of the foot (all bilaterally) in 10 palmar hyperhidrotic patients before, during, and after T2 ganglionectomy and sympathectomy. In both methods, ganglionectomy and sympathectomy were done by percutaneous stereotactic thermocoagulation, under local anesthesia, at room temperature 21.4 +/- 0.6 degrees C. During the procedure we found a significant acute decrease in systolic and pulse pressures, from 153 +/- 10 to 127 +/- 9 and from 80 +/- 7 to 56 +/- 4mmHg respectively, and a lesser decrease in diastolic pressure; heart rate showed no statistically significant changes. We also noted a marked increase in thumb temperature, from 21.2 +/- 0.6 to 36.0 +/- 0.1 degrees C, with a mean increase of 14.8 degrees C, at a room temperature 21.4 +/- 0.6 degrees C, after complete bilateral T2 ganglionectomy and sympathectomy. Skin temperature at the forehead, axilla, loin, and sole of the foot, all measured bilaterally, showed no significant increase, although there was a decrease in sweating in both forehead and axillary regions. The decrease in systolic and pulse pressures observed during the thermocoagulation procedure were temporary effects. The increase in thumb temperature, however, appears to be a permanent effect for palmar hyperhidrotic patients. Finally, the data indicate that the sympathetic innervation of the blood vessel in the periphery presents a segmental organization.

Complications of midgut carcinoid tumors and carcinoid syndrome

The carcinoid syndrome, associated with carcinoid tumors of the midgut, consists of symptoms such as diarrhea, flushing, wheezing and cardiovascular symptoms. This review focuses on these symptoms and discusses therapeutic options. The symptoms are caused by the secretion of biogenic amines, polypeptides and other factors of which serotonin is the most prominent. However, diarrhea is also due to factors such as malabsorption. Besides antitumor therapy, more specific interventions such as serotonin receptor blockers can be useful. The carcinoid heart disease involves the tricuspid and pulmonary valve. In the pathogenesis, serotonin plays a central role. The therapeutic approach is mostly symptomatic. Other cardiovascular complications include bowel ischemia and hypertension. Pellagra and psychiatric symptoms are due to a depletion of tryptophan, which is consumed by the carcinoid tumor for serotonin synthesis. Finally, follow-up and clinical practice of patients with carcinoid tumors are discussed.

Mast cells and biogenic amines in radiation-induced pulmonary fibrosis

Sprague-Dawley rats were exposed to a single X-ray dose of 30 Gy over the lungs and examined at 1-wk intervals during the following 3 to 8 wk. Mast cells were counted after specific staining with toluidine blue at a low pH and the mast-cell amines, histamine (Hi) and serotonin (5-HT), were measured using high-performance liquid chromatography. Irradiation induced pneumonitis followed by pulmonary mast-cell hyperplasia and progressive fibrosis 4 to 8 wk after irradiation. By week 4, immature-looking mast cells with a few granules started to appear, followed by a gradual increase in mast cells that reached very high levels after 8 wk, up to 40 to 200 times the normal. The pulmonary Hi and 5-HT content increased concomitantly from 6 and 1 micrograms/g to a maximum of 200 and 18 micrograms/g, respectively. These high levels of amine content and mast-cell densities greatly exceed those of any normal tissue. There was a strong correlation between the Hi and 5-HT content in both normal (r = 0.87) and irradiated (r = 0.93) lung tissue, as well as between the mast-cell density and amine content after irradiation (r = 0.86), thereby indicating that both amines derived from mast cells. The Hi/5-HT quotients were much lower in both normal and irradiated lung tissue (5 and 9, respectively) than in other tissues where these amines are stored in mast cells, or in isolated peritoneal mast cells (43). This relatively higher 5-HT content in pulmonary mast cells suggests that this amine performs a specific function in the lung.