Gitelman syndrome (GS) is an autosomal recessive salt-wasting disorder caused by mutations in the SLC12A3 gene ^[1], encoding the thiazide-sensitive sodium-chloride cotransporter (NCC) in the distal convoluted tubule ^[2]. It typically presents during adolescence or early adulthood with nonspecific symptoms such as fatigue, muscle cramps, or paresthesia. Biochemically, Gitelman syndrome is characterized by hypokalemia, hypomagnesemia, metabolic alkalosis, and hypocalciuria ^[3].

Although classically a disease of the young, Gitelman syndrome may present later in life, especially when mild or masked by comorbid conditions. In such cases, diagnosis may be delayed or missed altogether ^[4]. Seizures are a rare manifestation and usually reflect severe underlying electrolyte imbalance, particularly hypomagnesemia ^[5]. Here, we report a case of late-onset Gitelman syndrome in an elderly male presenting with seizures and hypokalemic paralysis.

A 65-year-old male presented to the geriatric outpatient department with progressive generalized weakness and multiple episodes of vomiting over two weeks. Two days prior to presentation, he developed two episodes of generalized tonic-clonic seizures followed by flaccid weakness in both lower limbs, resulting in inability to ambulate.

He had a past history of systemic hypertension and a cerebrovascular accident (CVA) nine months ago. Brain MRI revealed a frontoparietal lacunar infarct and an incidental arachnoid cyst (48 × 38 mm). He had no previous seizures. He was not on any medications associated with electrolyte disturbances, except for a brief use of cognition enhancers and ayurvedic preparations.

On examination, he was hemodynamically stable. Neurological examination revealed decreased muscle tone and reduced power (MRC grade 3/5) in both lower limbs. Cranial nerves, reflexes, and higher mental functions were normal.

Investigations showed profound hypokalemia (1.2 mmol/L), hypomagnesemia (1.5 mg/dL), metabolic alkalosis on ABG, and hypocalciuria. Urinary potassium was elevated. Serum renin and aldosterone were within normal limits. Other labs revealed subclinical hyperthyroidism, normal homocysteine, and a normal low-dose dexamethasone suppression test.  ECG showed bradyarrhythmia with U-waves and flattened T-waves. Ultrasonography of the abdomen and pelvis was normal. MRI findings were consistent with previous infarct; no acute lesions were found.

The patient was admitted and treated with intravenous potassium chloride (1000 mEq over several days), intravenous magnesium sulfate (4 ampules), and supportive care. Gradual clinical improvement was observed.

He was discharged on: levetiracetam 500 mg BD, clopidogrel 75 mg OD, escitalopram 10 mg OD, spironolactone 50 mg OD, potassium chloride syrup 15 ml OD for 5 days, and desloratadine 5 mg OD for 5 days.

At follow-up after 2.5 months, he remained seizure-free and regained full muscle strength.

Table 1: RFT on the day of presentation

Table 2: Other Urinary Investigations

Table 3: Other investigations

Table 4: ABG at the time of presentation

Table 5: Timeline of Clinical Events

Gitelman syndrome is estimated to affect approximately 1 in 40,000 individuals, though the carrier frequency may approach 1% ^[3]. It results from mutations in SLC12A3, impairing sodium and chloride reabsorption via the NCC channel in the distal convoluted tubule ^[1,2]. This leads to increased distal sodium delivery, with compensatory loss of potassium and magnesium. Concurrently, volume contraction stimulates proximal calcium reabsorption, contributing to the hallmark finding of hypocalciuria ^[6].

Most patients present during adolescence or early adulthood, but atypical late-onset cases have been reported and may go unrecognized in older adults ^[7,8]. In our patient, the diagnosis was considered due to the biochemical constellation of hypokalemia, hypomagnesemia, metabolic alkalosis, and hypocalciuria, in the absence of other obvious causes.

Seizures are not a typical feature of Gitelman syndrome but can occur in the setting of severe hypomagnesemia. Magnesium deficiency has been shown to reduce neuronal threshold and promote hyperexcitability, increasing susceptibility to seizures ^[9]. In our case, the combination of profound hypokalemia and hypomagnesemia likely triggered generalized tonic-clonic seizures.

Bartter syndrome was excluded based on the late age of presentation, normotension, and hypocalciuria. Other causes, such as chronic diuretic use, gastrointestinal losses, and surreptitious vomiting, were excluded by history and biochemical findings.

The diagnosis in this case was made clinically and biochemically, as genetic testing was not available due to financial constraints. While confirmation via SLC12A3 gene sequencing is ideal, it is not always feasible in resource-limited settings. In such cases, a syndromic diagnosis based on classic electrolyte abnormalities may suffice.

Similar reports have been described in the literature. Puthenkote et al. presented cases where Gitelman syndrome manifested with seizures, an uncommon presentation likely linked to electrolyte disturbances ^[9]. Bowatte et al. reported diagnostic challenges in atypical Gitelman syndrome cases, especially given overlaps with other causes of hypokalemia and the complexity of managing chronic electrolyte imbalances in older adults ^[4]. Annadatha et al. described Gitelman syndrome masquerading as hypokalemic periodic paralysis, emphasizing the diagnostic pitfalls that mimic other neuromuscular disorders ^[10]. These reports stress the importance of comprehensive biochemical and genetic evaluation in elderly patients with hypokalemia and neuromuscular symptoms. Karaahmetoğlu and Coşkun documented a case of incidental Gitelman syndrome diagnosis in an elderly patient, reinforcing that Gitelman syndrome can remain undiagnosed due to subtle symptomatology or overlap with age-related comorbidities.^[8] Sun et al. highlighted recurrent falls as a presenting symptom of Gitelman syndrome in octogenarians, a presentation that may overlap with neurological or musculoskeletal etiologies, adding to diagnostic complexity. Such falls may result from hypokalemia-induced muscle weakness or electrolyte imbalance-induced neurological dysfunction ^[11]. These cases, along with our own, highlight the importance of maintaining a high index of suspicion even in elderly patients

This case demonstrates a rare presentation of Gitelman syndrome in an elderly patient, manifesting with seizures and hypokalemic paralysis. Clinicians should consider Gitelman syndrome in the differential diagnosis of unexplained electrolyte abnormalities in older adults. Early recognition and correction of imbalances can prevent serious complications and result in complete recovery

Conflict of Interest: None declared
Funding:

 None
Ethical Clearance: Not obtained, as this is a retrospective single-patient report.
Patient Consent: Informed consent for publication was obtained.

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