A 38 years old gentleman brought to emergency room with complaints of recurrent vomiting for 7 days, dizziness for 5 days, and gait imbalance along with visual perception of oscillatory movements of objects for last 2 days. There was no history of tremors/ diplopia/motor deficits/ or altered sensorium or seizures. History of fever/ chronic drug exposure/ thyroid disorder/Jaundice was absent. There was no history of alcohol consumption. Hypertension was present but controlled for last 1 year. There was history of receiving influenza vaccine 1 week back. On examination, Pt was alert with normal higher mental functions. Vitals were stable. Cranial nerve examination revealed bilateral downbeat nystagmus. Kayser Fleischer (KF) ring was absent. Fundus was normal. There was no motor or sensory deficits and reflexes were normal. Cerebellar examination revealed dysdiadokinesia, impaired finger nose finger test, impaired heel shin test. Gait was ataxic with left sided deviation.
Initial Lab investigations revealed normal complete blood count, (Liver function test) LFT, (Kidney Function Test) KFT with normal, (thyroid peroxidase) TPO Antibodies. Thyroid Stimulating hormone (TSH), Free triiodothyronine (FT3) and Free Throxine (FT4) were normal. Serum Mg was low, 0.25 mg/dl (1.8–2.5). Serum calcium, Potassium and albumin were normal. Leptospira and chikangunya serology was negative. Serum Angotensin converting enzyme (ACE) was normal (13.1 U/L). Serum Vitamin B12 levels were in normal range. Viral markers were negative. Vasculitic and autoimmune profiles were negative. Paraneoplastic Profile result showed positive anti YO (qualitative) antibody. Fluorodeoxyglucose (FDG)-positron emission tomography (PET) scan was normal. Cerebrospinal fluid (CSF) analysis was done which was normal (Cells: 5 (all lymphocytic) Protein: 126 mg/dl, Glucose: 56 mg/dl (Blood sugar: 90 mg /dl)).
Treatment started with intravenous magnesium after which imbalance and vertigo improved. Pt was discharged on maintenance dose of magnesium. After 3 months, pt. came back with multiple episodes of whole body stiffness, uprolling of eyes, vigorous shaking, irritability, Short term memory loss, night time hallucinations. This time Serum magnesium levels were 0.9 mg/dl. Magnesium was replaced again this time, pt. improved gradually. Work for recurrent hypomagnesaemia was done which was negative. Patient was on proton pump inhibitors. On stopping it, patient improved significantly. Magnetic Resonance Imaging (MRI) brain at the time of admission was showing hyperintensity at left cerebellar hemisphere which disappeared after 4 weeks of definite management. (Fig. 1a and b).