Novel brain MRI abnormalities in Gitelman syndrome

Abstract

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.

Gitelman Syndrome: A Rare Cause of Seizure Disorder and a Systematic Review

“…A less common association is seen with empty sella syndrome in 2 patients. Seizure disorder as a possible association with GS was previously reported in only one case by Beltagi et al, most likely due to hypomagnesemia [15]. Our patient, however, was unique with no prior history of epilepsy and had a seizure as the very first presentation with normal magnesium levels.…”

“…Our case reports are unique in this sense that the patient of GS presented with seizure despite having normal serum magnesium levels. In our literature review, only one patient who was reported by Beltagi et al [15] presented with somnolence and altered mental status and had a focal seizure as a complication. Even in that case, hypomagnesemia can be considered as the cause of epileptiform activity on EEG.…”

“…Most patients with GS remain untreated. The observation that chondrocalcinosis is due to magnesium deficiency argues clearly in favor of magnesium supplementation [15]. Most asymptomatic patients with GS remain untreated and undergo ambulatory monitoring, once a year, generally by nephrologists.…”

The atypical form of Gitelman syndrome with cerebral calcifications

“…Мы впервые в отечественной педиатрической нефрологии наблюдали редкую форму тубулопатии -атипичный синдром Гительмана с церебральными кальцификатами. В зарубежной литературе нам встретились единичные работы, в которых описывается кальцификация базальных ганглиев у пациентов с данным синдромом [9,12,[19][20][21][22]. A. Beltagi и соавт.…”

“…A. Beltagi и соавт. (2015) трактовали церебральные кальцификаты при синдроме Гительмана как следствие энцефалопатии при митохондриальной цитопатии [12]. Под нашим наблюдением находились 4 пациента с синдромом Гительмана, у одного из них выявлена атипичная форма с церебральными кальцификатами.…”