Movement Disorders and Renal Diseases

Abstract

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.

Keywords: movement disorders; nephropathy; neurogenetics..

FIG. 1

Manifestations of glomerulopathy in disorders with movement abnormalities. ⁵² Abbreviations: GFR, glomerular filtration rate; MCARN, mitochondrial cerebellar ataxia, renal failure, neuropathy, and encephalopathy; NARP, neurogenic muscle weakness, ataxia, and retinitis pigmentosa.

FIG. 2

General and site‐specific manifestations of tubulopathy in disorders with movement abnormalities. ⁵³ Abbreviations: CoQ₁₀, coenzyme Q₁₀; EAST, epilepsy, ataxia, sensorineural deafness, and tubulopathy; KSS, Kearns‐Sayre syndrome; MERRF, myoclonic epilepsy with ragged‐red fibers; MMA, methylmalonic aciduria; mtDNA, mitochondrial deoxyribonucleic acid; nDNA, nuclear deoxyribonucleic acid; OCRL, oculocerebrorenal syndrome of Lowe; PS, Pearson syndrome; RTA, renal tubular acidosis. ^aMechanism of renal dysfunction is not clearly known but there is indirect evidence of tubulopathy. ^bThere is dysfunction of specific neutral amino acid transporter in the proximal convoluted tubule. ^cRhabdomyolysis can be caused by acquired and inherited movement disorders (see Supplementary Table S1).