Autonomic neuropathy and secondary hyperparathyroidism in uremia

Severe Acro-osteolysis Mimicking Arthritis Mutilans in a Patient with Primary Hyperparathyroidism: A Case Report

BACKGROUND

Primary hyperparathyroidism (PHPT) should be considered in the differential diagnosis of a patient with suspected secondary osteoporosis, and severe osteoporosis with multiple fractures is frequently the first clinical manifestation of the disease.

CASE PRESENTATION

Mutilating arthritis (arthritis mutilans) can be part of the clinical presentation of a number of rheumatic diseases, most commonly seen in psoriatic arthritis, rheumatoid arthritis, and juvenile idiopathic arthritis, but also in systemic lupus, systemic sclerosis, and multicentric reticulohistiocytosis. Evidence exists that subperiosteal and subchondral bone resorption, seen in PHPT, could induce the so-called 'osteogenic synovitis', which could eventually lead to the development of a secondary osteoarthritis with bone deformities.

CONCLUSION

Here, we present a case report of a patient initially diagnosed with PHPT who presented with mutilating arthritis of the finger joints and discuss whether the severe acro-osteolysis is a manifestation of the endocrinopathy or whether there is a co-existing undiagnosed inflammatory joint disease.

There is No Association between Cardiovascular Autonomic Dysfunction and Peripheral Neuropathy in Chronic Hemodialysis Patients

BACKGROUND AND PURPOSE

The potential association between the severity of autonomic dysfunction and peripheral neuropathy has not been extensively investigated, with the few studies yielding inconsistent results. We evaluated the relationship between autonomic dysfunction and peripheral neuropathy in chronic hemodialysis patients in a cross-sectional study.

METHODS

Cardiovascular autonomic function was assessed in 42 consecutive patients with chronic renal failure treated by hemodialysis, using a standardized battery of 5 cardiovascular reflex tests. Symptoms of autonomic dysfunction and of peripheral neuropathy were evaluated using the Autonomic Neuropathy Symptom Score (ANSS) and the Neuropathy Symptoms Score. Neurological deficits were assessed using the Neuropathy Disability Score. Conduction velocities along the sensory and motor fibers of the sural and peroneal nerves were measured. Thermal thresholds were documented using a standardized psychophysical technique.

RESULTS

Parasympathetic and sympathetic dysfunction was prevalent in 50% and 28% of cases, respectively. Peripheral neuropathy was identified in 25 cases (60%). The prevalence of peripheral neuropathy did not differ between patients with impaired (55%) and normal (75%) autonomic function (p=0.297; Fisher's exact test). The electrophysiological parameters for peripheral nerve function, neuropathic symptoms, abnormal thermal thresholds, age, gender, and duration of dialysis did not differ significantly between patients with and without autonomic dysfunction. Patients with autonomic dysfunction were more likely to have an abnormal ANSS (p=0.048). The severity of autonomic dysfunction on electrophysiological testing was positively correlated with ANSS (r=0.213, p=0.036).

CONCLUSIONS

The present data indicate that although cardiovascular autonomic dysfunction is prevalent among patients with chronic renal failure, it is not associated with the incidence of peripheral neuropathy.

Sympathetic skin response and R-R interval variation in chronic uremic patients

Sympathetic skin response (SSR) and R-R interval variation (RRIV) were studied in 36 chronic, nondiabetic uremics to compare with their nerve conduction studies (NCS) and clinical dysautonomia. Abnormal SSR was noted in 5 (13.9%) patients, abnormal RRIV in 14 (38.9%), and abnormal NCS in 26 (72.2%). The patients were classified into three groups: group (GP) 1: "normal," n = 21 (58.3%), normal RRIV and SSR; GP 2: "isolated parasympathetic dysfunction," n = 10 (27.8%), abnormal RRIV and normal SSR; and GP 3: "sympathetic sudomotor dysfunction," n = 5 (13.9%), abnormal SSR. A significant difference in age was found among the three groups (GP 3 > GP 2 > GP 1; P < 0.0001, ANOVA). After controlling the age factor, we still noted a tendency toward increasing NCS disturbances (distal latency and nerve conduction velocity of peroneal nerve; P < 0.05, multiple regression analysis) and frequencies of clinical autonomic symptoms (postural dizziness and impotence; P < 0.05, Mantel-Hanszel test) from GP 1 to GP 3. Patients with abnormal SSR (GP 3) displayed significantly higher frequencies of postural dizziness and impotence, indicating the relationship between an absence of SSR and clinical dysautonomia.