Diabetic uremic syndrome

Movement Disorders and Renal Diseases

Movement disorders often emerge from the interplay of complex pathophysiological processes involving the kidneys and the nervous system. Tremor, myoclonus, ataxia, chorea, and parkinsonism can occur in the context of renal dysfunction (azotemia and electrolyte abnormalities) or they can be part of complications of its management (dialysis and renal transplantation). On the other hand, myoglobinuria from rhabdomyolysis in status dystonicus and certain drugs used in the management of movement disorders can cause nephrotoxicity. Distinct from these well-recognized associations, it is important to appreciate that there are several inherited and acquired disorders in which movement abnormalities do not occur as a consequence of renal dysfunction or vice versa but are manifestations of common pathophysiological processes affecting the nervous system and the kidneys. These disorders are the emphasis of this review. Increasing awareness of these conditions among neurologists may help them to identify renal involvement earlier, take timely intervention by anticipating complications and focus on therapies targeting common mechanisms in addition to symptomatic management of movement disorders. Recognition of renal impairment in a patient with complex neurological presentation may narrow down the differentials and aid in reaching a definite diagnosis.

Diabetic uremic syndrome studied with cerebral MR spectroscopy and CT perfusion

Diabetic uremic syndrome (DUS) is an increasingly reported acute neurometabolic cerebral disease with characteristic clinical and imaging features. Clinical spectrum includes a wide range of movement disorders such as acute parkinsonism. Imaging studies show reversible (with hemodialysis) bilateral lesions in the lenticular nuclei. DUS pathophysiology has not been entirely clarified yet. Our case study shows certainly that LN lesions are characterized with increased lactate peak with MR spectroscopy and decreased perfusion in computerized tomography perfusion along with increased diffusion with apparent diffusion coefficient (ADC) mapping in the subacute phase of the syndrome. Abnormalities were almost normalized quickly after metabolic control by hemodialysis. Together with reports indicating that a deficit of glucose use exacerbated with acute increase of uremic toxins in bilateral LN, observed changes (lactate peak and hypoperfusion) led us to state that a primary metabolic depression may cause this syndrome. Metabolic depression is probably due to uncompensated uremic toxin accumulation related mitochondrial supression and/or dysfunction. This definition fits well to the other elements of DUS such as ADC evolution and marked lesion regression. Our single case study is not supportive of other previously credited mechanisms such as microvascular dysfunction related focal ischemia or hypoperfusion, prolonged uremic toxin related histotoxic hypoxia, central pontine myelinolysis-like demyelination and posterior leukoencephalopathy spectrum disorder related vasogenic edema.

[A case of subacute parkinsonism presenting as bilateral basal ganglia legions by MRI in diabetic uremic syndrome]

A 60-year-old male was admitted because he had developed tremulous movement in both upper and lower limbs and gait disturbance over the course of 3 months. He had been on continuous ambulatory peritoneal dialysis almost 1 year earlier due to end-stage diabetic nephropathy. A neurological examination revealed a mild disturbance of his consciousness, asterixis in the upper limbs, bilateral extensor plantar responses and parkinsonism, which were characterized by bradykinesia, akinesia, rigidity, and bilaterally tremors at rest. Cranial magnetic resonance imaging (MRI) revealed swollen bilateral basal ganglia legions, which appeared hyperintense on T2-weighted images. The patient was treated for metabolic acidosis and continued hemodialysis three times a week; however, the parkinsonism remained 1 year later. Follow-up MRI revealed decreased swelling of the basal ganglia, and the pattern of diffusion-weighted images and the apparent diffusion coefficient (ADC) map indicated vasogenic and cytotoxic edema in bilateral globus pallidus. The case was diagnosed as encephalopathy due to diabetic uremic syndrome, initially characterized by Wang et al. (2003). Only 17 cases with parkinsonism have been reported. Diabetic uremic syndrome is characterized by acute or subacute onset consciousness disturbance and movement disorders such as parkinsonism, chorea and the other extrapyramidal signs to various degrees related to bilateral lesions of the basal ganglia.

Increased risks of parkinsonism in the 3 years after chronic renal failure

AIMS

Movement disorders are one of the central nervous system complications in uremic patients. Asterixis, multifocal myoclonus, and restless leg syndrome are well-documented in this category. Acute parkinsonism, however, is only reported in rare series with a small number of cases. In this study, we investigated the risk for parkinsonism during a 3-year follow-up period after a diagnosis of uremia.

METHODS

The Longitudinal Health Insurance Database in Taiwan was utilised. We identified a total of 2862 patients who had visited ambulatory care centers with a diagnosis of chronic renal failure between 1999 and 2001 as the study cohort. We further randomly selected 14,310 enrollees matched with the study cohort in terms of gender, age, and year of their index visit for comparison. Each patient was individually tracked for 3 years to identify the occurrence of parkinsonism. Stratified Cox proportional hazard regressions (stratified by age and gender) were performed for analyses.

RESULTS

We found the annual incidence rates of parkinsonism to be 1.2% and 0.6% in the uremic and non-uremic groups, respectively. Furthermore, uremic patients were more vulnerable to developing parkinsonism with a 1.81-fold higher risk [95%CI = (1.21-2.71)] than the non-uremic group after adjusting for diabetes mellitus, which did not augment the risk.

CONCLUSIONS

The importance of raising awareness regarding the early symptoms of parkinsonism among patients with uremia is tied to its early identification, with timely aggressive dialysis being able to apply to slow the progression of the disease and its symptoms. Further study is warranted to elucidate the pathophysiology of uremic parkinsonism.