Fahr's syndrome as the initial imaging characteristics of MELAS syndrome with a possible seizure activity and cardiac arrest: a case report

Abstract

This study reported a case of MELAS syndrome presenting as the initial imaging characteristics of Fahr's syndrome with "near" sudden unexpected death in epilepsy (SUDEP) and lateralized periodic discharges (LPD). The patient, a young boy, experienced loss of consciousness 2 days prior, which was followed by two limb and facial convulsions. He was later found in cardiac arrest during hospitalization, but regained consciousness gradually after receiving cardiopulmonary resuscitation and tracheal intubation. The patient exhibited short stature, intellectual disability, poor sports abilities, and academic performance since childhood, but had no family history. Emergency head computed tomography (CT) revealed high density calcification in bilateral caudate nucleus, lentiform nucleus, thalamus, and dentate nucleus with evidence of an acute process. The patient was transferred to the neurology department where he continued to recover consciousness, though he experienced dysarthria, left limb hemiplegia, and hemiparesthesia. Changes in head magnetic resonance imaging (MRI) findings were noted at admission, 1 month later, and 6 months later. LPD were observed in his video electroencephalogram. The CT urography indicated a narrow left ureteropelvic junction with left hydronephrosis, which was suggestive of ureteropelvic junction obstruction. Ultimately, a diagnosis of near-SUDEP was suspected in this patient, indicating a rare case of MELAS syndrome with near-SUDEP and LPD. The gene tests results revealed the presence of the mitochondrial DNA A3243G mutation, leading to the final diagnosis of MELAS syndrome. This case expands the clinical disease spectrum of the MELAS syndrome.

Keywords: Fahr’s syndrome; LPD; MELAS syndrome; UPJO; near-SUDEP.

FIGURE 1

Imaging characteristics at admission and follow-up of this patient. (A) Symmetrical calcification of bilateral basal ganglia and thalamus was showed in head CT at admission; (B) CT urography showed that the left ureteropelvic junction was narrow with left hydronephrosis; (C) No abnormality in the head CTA. (D–F) Showed the cranial MRI T2flair characteristics of this patient at admission, after 1 month and 6 months of follow-up. After admission, only the right occipital cortex showed laminated high signal (D). One month later, the patient showed typical high signal intensity area in the right occipital lobe (E). Six months later, the right occipital lobe lesion disappeared and transferred to the left occipital cortex (F).

FIGURE 2

The video EEG characteristics at the first admission and 1-month follow-up of this patient. (A) Showed typical spine and slow wave distribution (00:15:07), mainly in area of Fp2-F4 and Fp2-F8, and conducted to Fp1-F3 at 222 m, and no clinical onset of the patient was observed (at admission) (Montage:Bipolar longitudinal connection, TR:30 mm/s, Sensitivity:100 μV/cm, HF:40 Hz, LF:1.0 Hz). (B) Showed lateralized periodic discharges (LPD) composed of sharp slow wave, interval cycle: 1.17–1.58 s, mainly in area of O1, no clinical onset of the patient was observed (1 month later) (Montage:Earlobe reference, TR:30 mm/s, Sensitivity:100 μV/cm, HF:70 Hz, LF:1.0 Hz).