Table 1.

Clinical characteristics and laboratory findings on admission

Patients		At the time of disease onset	On admission
	Age (years)	Clinical feature	Age (years)	Clinical features	Laboratory finding (serum)
					Lactic acid (mmol/L) (<2.0 normal)	Creatine kinase (IU/L) (22 ~ 270 normal)	Brain MRI findings
1	9	Twitching,stroke like episode	11	Deafness, twitching, glossolalia, mobility limitation	6.7	118	Patchy T1 and T2 abnormal signals in right temporal, occipital and parietal lobes and left parietal lobes.
2	1	Mobility limitation	3	Mobility and speaking limitation, amyotrophy, monophasia	4.58	276	Spotted T1 and T2 abnormal signals in left corona radiata.
3	12	Vomiting,headache, diarrhea	13	Vomiting, lethargy, hypophrenia, speaking and mobility limitation	4.5	602	Multiple patchy T1 and T2 abnormal signals in bilateral cerebellar hemisphere, both occipital lobes and right parietal lobe.
4	9	Vomiting, headache, lethargy	9	Vomiting, headache, lethargy, positive reflex	2.8	766	Large patchy T1 and T2 abnormal signals in left temporo-occipito-parietal lobes.
5	11	Pitting edema, tachycardia, blurred vision, seizures	11	Pitting edema, tachycardia, blurred vision, seizures	3.0	277	Large patchy T1 and T2 abnormal signals in bilateral temporo-occipito-parietal lobes.
6	1	Progressive motor retardation, tremor, ptosis	1	Progressive motor retardation, tremor, ptosis	3.9	138	Abnormal signals in bilateral cerebral peduncle and brainstem tegmental area.

Note: The mean level of lactic acid was 4.25 ± 1.41 mmol/L, the mean level of creatine kinase was 362.83 ± 262.73 IU/L. These brain MRI findings represent those at admission, subsequent brain MRI during follow up showed different degree of changes in different sites.