Gitelman syndrome is an autosomal recessive renal tubular disorder characterized by hypokalemic metabolic
alkalosis, hypomagnesemia and hypocalciuria. The syndrome is caused by a defective
thiazide-sensitive
sodium chloride co-transporter in the distal convoluted tubules of the kidneys.
Gitelman syndrome could be confused with
Bartter syndrome; the main differentiating feature is the presence of low urinary
calcium excretion in the former. Descriptions of neuroradiological imaging findings associated with
Gitelman syndrome are very scarce in the literature and include basal ganglia calcification,
idiopathic intracranial hypertension and sclerochoroidal calcification.
Cauda equina syndrome-like presentation has been reported, but without any corresponding imaging findings on lumbar spine MRI. We report a 13-year-old male with
Gitelman syndrome who presented with altered mental status following a fall and scalp
laceration and unremarkable brain CT, followed during hospitalization by
somnolence and
seizures. Metabolically the patient demonstrated
hypokalemia and hypomagnesemia. MRI demonstrated features of
encephalopathy including predominantly right-sided cerebral hemispheric signal abnormality and cytotoxic
edema, with bilateral symmetric involvement of the thalami, midbrain tegmentum and tectum and cerebellar dentate nuclei. MRI after five months obtained during a later episode of
encephalopathy showed resolution of the signal abnormalities with setting in of brain
atrophy and also areas of newly developed cytotoxic
edema in the left thalamus, bilateral dorsal midbrain and right greater than left dentate nuclei. The described abnormalities, either recurrent or in isolation, have not previously been published in patients with
Gitelman syndrome. We believe that the findings are due to alteration of respiratory chain function secondary to the metabolic derangement and hence have a similar imaging appearance as
encephalopathy related to
mitochondrial cytopathy or
metabolic encephalopathy.