Ophthalmologic Manifestations in MELAS Syndrome Woan Fang, MD; Chin-Chang Huang, MD; Chen-Chun Lee, MD; Shaw-Yi Cheng, MD; Cheng-Yoong Pang; Yau-Huei Wei, PhD \s=b\ We describe a 15-year-old boy with full-blown mitochondrial myopathy, encephalopathy, lactic acidosis, and strokelike episodes (MELAS) and chronic progressive external ophthalmoplegia (CPEO). He presented with visual disturbance, hearing impairment, continuous partial epilepsy on the right aspect of the face, and right hemiparesis since the age of 13. Four months later, he experienced another strokelike episode with continuous partial epilepsy on the left hand. Serial computed tomographic scans revealed bilateral parieto-occipital hypodense lesions with gyral enhancement and an additional low-density lesion in the right frontal area 4 months later, respectively. Results of laboratory examinations disclosed lactic acidosis and mitochondrial myopathy with many ragged-red fibers. To identify the defective gene in mitochondrial DNA, a simple molecular test was performed by using restriction endonuclease Apa I. A transition from A to G was found at nucleotide position 3243 of the tRNALeu gene. Interestingly, the patient also had marked external ophthalmoplegia and ptosis commonly found in patients with CPEO. Therefore, we suggest that ophthalmoplegia also occurs in the MELAS syndrome. (Arch Neurol. 1993;50:977-980) encephalomyopathy Mitochondrial group may is a heterogeneous of disorders that affect multiple sys¬ the central nervous system, peripheral tems, nerves, skeletal muscle, heart, liver, kidney, retina, and other organs.1,2 They encompass the following several ma¬ jor distinct syndromes: Kearns-Sayre syndrome (KSS),3,4 chronic progressive external ophthalmoplegia (CPEO),5 myoclonic epilepsy with ragged-red fibers (MERRF),6,7 and mitochondrial myopathy, encephalopathy, lactic acidosis, and strokelike syndrome (MELAS).8,9 The CPEO is charac¬ terized by progressive external ophthalmoplegia and pto¬ sis with marked degeneration of the extraocular muscles. The MERRF syndrome is characterized by myoclonic ep¬ ilepsy with cerebellar ataxia, and MELAS by strokelike episodes with headache, nausea, and vomiting. These including Accepted for publication August 17, 1992. From the Department of Neurology, Chang Gung Memorial Hospital (Drs Fang, Huang, and Cheng), the Department of Neurology, China Medical College Hospital (Dr Lee), and the Department of Biochemistry, National Yang-Ming Medical College (Mr Pang and Dr Wei), Taipei, Taiwan, Republic of China. Reprint request to Department of Neurology, Chang Gung Memorial Hospital, Chang Gung Medical College, 199 Tung-Hwa North Rd, Taipei, Taiwan, Republic of China (Dr Huang). main characteristic features provide a good clue in differ¬ entiating these syndromes. However, a few cases of MELAS or MERRF syndrome associated with the clinical presentation of KSS have been described.912 In these cases, no mutations in mitochondrial DNA (mtDNA) were iden¬ tified. We recently encountered a patient whose clinical features and genetic defect were consistent with the MELAS syndrome. Additionally, he also had the promi¬ nent external ophthalmoplegia commonly found in pa¬ tients with CPEO. Herein, we report the clinical picture and emphasize the importance of mtDNA analysis in the diagnosis of mitochondrial disease with overlapping syn¬ dromes. REPORT OF A CASE A 15-year-old boy had a normal birth and perinatal develop¬ ment. His family history was noncontributory. In a survey of his family members, no optic atrophy was found. He was rather healthy until the age of 8 years, when he incurred the sudden on¬ set of visual disturbance in both eyes. Bilateral optic atrophy with hand movements within 2 cm in visual acuity was noted 3 months later. At the age of 10 years, progressive hearing impairment and growth retardation developed. His general condition remained stable until 1.5 months before his admission to the hospital. Ep¬ isodic headache, nausea, and vomiting were noted in late November 1989. One month later, he experienced several epi¬ sodes of focal motor seizure over the right aspect of his face with marching to the right hand. He was admitted to the neurologic department of our hospital on lanuary 4, 1990, because of the sudden onset of right limb weakness. On evaluation, he was alert but asthénie, with a body weight of 28 kg and a body length of 133 cm. Results of an ophthalmologic examination showed severe external ophthalmoplegia and mild ptosis in both eyes (Fig 1) and bilateral visual impairment with only light perception in both eyes. Mild nystagmus was noted during gazing. There was optic atrophy but no retinitis pigmentosa. Neurologically, he had a bi¬ lateral neurosensory type of hearing loss, right hemiparesis, and hemianesthesia. Deep tendon reflexes were generally absent. He also showed mental retardation. Neither myoclonus nor cerebel¬ lar signs were noted. The serum lactate concentration was 6.0 mmol/L (normal, 0.8 to 2.4 mmol/L), and the serum pyruvate concentration was 57 µ /L (normal, 34 µ /L to 102 µ / L). Results of other routine hemograms and blood chemistry studies were normal, except that the creatine kinase concentration was 215 U/L (normal, 15 to 130 U/L), alanine aminotransferase concentration was 92 U/L (normal, 3 to 30 U/L), the aspartase aminotransferase concentration was 66 U/L (normal, 3 to 35 U/L), and the alkaline phosphatase concentration was 125 U/L (normal, 21 to 91 U/L). An electrocardiogram exhibited sinus ta¬ chycardia with a ventricular rate of 107 beats per minute and a Downloaded From: http://archneur.jamanetwork.com/ by a University of California - San Diego User on 06/09/2015 Fig 1.—Marked limitation of eyeball movements and mild ptosis on both eyes in gaze to both sides were noted in the patient. short P-R interval. Electroretinography revealed normal wave¬ forms and latencies of A and waves, but absence of PI 00 waves following each eye stimulation was noted by flashed-pattern visual-evoked potentials. Electroencephalography demonstrated diffuse slow waves and intermittent sharp waves with focal em¬ phasis on bilateral occipital areas. Generalized epileptiform dis¬ charges were also noted. A computed tomographic scan of the brain in lanuary 1990 revealed multiple low-density lesions in the right temporoparieto-occipital and left parieto-occipital areas with dilatation of bilateral occipital horns and bilateral basal ganglia calcification. After contrast medium injection, gyral enhancement was noted (Fig 2, top). Results of a motor nerve conduction velocity (MNCV) study disclosed temporal dispersion with decreased amplitude in com¬ pound muscle action potentials (CMAP) and slowing of MNCV of both peroneal and tibial nerves. Undetectable waves were found in the sensory nerve conduction velocity (SNCV) of both sural nerves but were relatively normal in both the median and the ulnar nerves. Results of an electromyogram were consistent with myopathy with spontaneous activities of fibrillations, pos¬ itive waves, and short duration with low-amplitude polyphasic waves. The electromyographic and NCV studies indicated pe¬ ripheral neuropathy, especially in the lower extremities. Muscle biopsy specimens were obtained from the right vastus lateralis muscle and stained with hematoxylin-eosin, modified Gomoritrichrome, succinate dehydrogenase, and nicotinamide adenine dinucleotide-tetrazolinum reducíase stains. When muscle sec¬ tions were stained by the hematoxylin-eosin method, some hypereosinophilic fibers and internal nuclei associated with vari¬ ability in fiber size were noted. Some of the muscle fibers showed a ragged-red appearance in the sections stained by the modified Gomori-trichrome method. Succinate dehydrogenase and nicoti¬ namide adenine dinucleotide-tetrazolinum reducíase activities were also present, corresponding to the ragged-red fibers (Fig 3). Based on the above findings, a diagnosis of MELAS syndrome was made, and the patient was discharged on lanuary 13, 1990, receiving carbamazepine and clonazepam for seizure control. On April 20,1990, another episode of continuous partial epilepsy de¬ veloped over the left side of his face with head deviation to the left side and left hemiparesis. He was readmitted to this hospital, and a repeated computed tomographic scan revealed a new hypodense lesion in the right frontal area with mild resolution of bilateral parieto-occipital lesions (Fig 2, bottom). During the follow-up period, the patient experienced two episodes of acute complete hearing loss followed by rapid recovery several days later. On August 18,1990, acute painful paresthesia and general¬ ized muscle weakness occurred. Three days later, the painful symptom disappeared but a follow-up MNCV study showed de¬ terioration with prolongation of distal latency and decreased am- Fig 2.—A, First computed tomographic scan showed multiple hypodense lesions in the right temporoparieto-occipital and the left parieto-occipital areas and bilateral basal ganglia calcifications. B, Re¬ peated computed tomographic scan showed an additional hypodense lesion in the right frontal area with some resolution of bilateral parietooccipital lesions. plitudes of CMAP in both the median and ulnar nerves and undetectable waves in both the peroneal and tibial nerves. There was median, ulnar, and sural an absence of waveforms in the SNCV of a slow nerves. In the last year, he presented progression to com¬ plete loss of vision (even light perception), deafness, and aphasia and an occasional seizure due to withdrawal of anticonvulsant therapy. To identify the mitochondrial gene defect, a simple molecular Downloaded From: http://archneur.jamanetwork.com/ by a University of California - San Diego User on 06/09/2015 Fig 3.—Light microscopy of vastus lateralis muscle, a, Some hypereosinophilic fibers (arrows) and internal nuclei with variability in fiber size were present in hematoxylin-eosin stain (X400). b, Ragged-red fibers (arrows) were shown by modified Gomori trichrome stain (X400). c, Succinate de¬ hydrogenase activity was present corresponding to the ragged-red fibers (X400). d, Similar features were demonstrated by nicotinamide adenine dinucleotide-tetrazolium reducíase stain (X400). performed on the mtDNA isolated from the muscle of the patient using the restriction endonuclease Apa I. For restriction analysis with Apa I, a 1159-base pair (bp) fragment encompass¬ ing the putative mutation site (nucleotide position 3243) was am¬ plified by polymerase chain reaction from the muscle mtDNA of the MELAS patient using a pair of primers, H2678-2696 and L3817-3836. The polymerase chain reaction cycle lasted for 1 minute denaturation of DNA at 94°C, 1 minute annealing at 56°C, and 1 minute extension at 72°C. Amplification was done with 30 cycles. The polymerase chain reaction product was cleaved by I to give three fragments, including the undigested original Apa 1159 bp and the new 591-bp and 568-bp digested products (Fig 4). The only possibility that can create a new Apa I site in this 1159bp fragment to produce the 591-bp and 568-bp fragments is the test was G-to-A transition at nucleotide 3243 to cause mutation of wild type -GAGCCC- to the -GGGCCC- sequence. Thus, the result clearly demonstrated that an A-to-G transition at nucleotide po¬ sition 3243 in the mtDNA was heteroplasmic in the patient. The fraction of mutant mtDNA in the muscle was estimated by densitometry to be about 70%. COMMENT The MELAS syndrome, as reviewed by DiMauro et al,1 has a distinct clinical manifestation that would be unlikely to be confused with CPEO and MERRF. The patient pre¬ sented meets the criteria of MELAS syndrome with mito¬ chondrial myopathy (ragged-red fibers), encephalopathy (focal motor seizure and episodic headache), lactic acido¬ sis, and two strokelike episodes. The patient also had oth- er common features of short stature, sensorineural type of hearing loss, and mental retardation. The molecular anal¬ ysis for mtDNA defect also identified an A-to-G transition at nucleotide position 3243, which confirmed the diagno¬ sis of MELAS syndrome. Interestingly, some unusual pre¬ sentations of external ophthalmoplegia, optic atrophy, and polyneuropathy were also found. Clinically, KSS is characterized by onset before the age of 20 years, external ophthalmoplegia, atypical pigmentary degeneration of the retina, and heart block. Patients with KSS usually do not demonstrate hemiplegia and hemian¬ opsia, which are commonly found in patients with the MELAS syndrome. Drachman13 had reported two atypical cases of KSS complicated by optic atrophy instead of retinitis pigmentosa. Chronic progressive external oph¬ thalmoplegia consists of limitation of ocular movements and ptosis. Our patient did not fit the typical features of KSS, but he did seem to have the features necessary for CPEO. Ophthalmologic abnormalities have been reported in overlapping syndromes. Fritz et al10 described a mixed form of KSS and MERRF in a 20-year-old man who under¬ went cataract extraction. Dest'ee et al11 reported a second case of combined MELAS and KSS. The patient had a saltand-pepper retinopathy and hemeralopia and WolffParkinson-White syndrome. Küchle et al12 reported over¬ lapping syndromes with MELAS and KSS in a patient who had an atypical retinitis pigmentosa and nuclear cataract Downloaded From: http://archneur.jamanetwork.com/ by a University of California - San Diego User on 06/09/2015 and confirm rather than confuse the distinction among the major syndromes initially suggested by clinical criteria. Therefore, further investigation on mtDNA mutations in patients with mitochondrial disease of overlapping syn¬ drome is warranted to elucidate the molecular basis of this disease. We express our appreciation to Lily Lee for technical assistance and to E. Lee for typing the manuscript. References 1. DiMauro S, Bonilla E, Zeviani N, Nakagawa M, DeVivo DC. Mitochondrial myopathies. Ann Neurol. 1985;17:521-538. 2. Petty RK, Harding AE, Morgan-Hughes JA. The clinical features of mitochondrial myopathy. Brain. 1986;109:915-938. 3. Kearns TP, Sayre GP. Retinitis pigmentosa, external ophthalmoplegia and complete heart block. Arch Ophthalmol. 1958;60:280-289. 4. Berenberg RA, Pellock JM, DiMauro S, et al. Lumping or splitting? ophthalmoplegia-plus or Kearns-Sayre syndrome? Ann Neurol. 1977;1: 37-54. 5. Drachman DA. Ophthalmoplegia plus: a classification of the disorders associated with progressive external ophthalmoplegia. In: Vinken PJ, Bruyn GW. Handbook of Clinical Neurology. Amsterdam, the Netherlands: North\x=req-\ Holland; 1975;22:203-216. 6. Fukuhara N, Tokiguchi S, Shirakawa S, Tsubaki T. Myoclonus epilepsy associated with ragged-red fibers (mitochondrial abnormalities): disease entity or syndrome? light and electron microscopy studies of two cases and review of the literature. J Neurol Sci. 1980;47:117-133. 7. Berkovic SF, Carpenter S, Evans A, et al. Myoclonus epilepsy and ragged red fibers (MERRF), I: a clinical, pathological, biochemical, magnetic resonance spectrographic and positron emission tomographic study. Brain. Fig 4.—The Apa I restriction pattern of the polymerase chain reaction (PCR) fragments encompassing the 3243 mutation site in the mitochrondrial DNA (mtDNA) of the patient with mitochondrial myopathy, encephalopathy, lactic acidosis, and strokelike episodes. M represents the 123-base pair (bp) DNA ladder as size markers. Lanes 1 and 2 are the Apa l-digested and -predigested PCR fragment amplified from the muscle mtDNA of the patient using the primers H2678-2696 and L3817-3836. Lanes 3 and 4 are the Apa ¡-digested and -predigested PCR fragment amplified from the muscle mtDNA of a patient with myoclon¬ ic epilepsy with ragged-red fibers (negative control). in the right eye. In these three cases, no ophthalmoplegia reported. To our knowledge, ophthalmoplegia has never been reported in the MELAS syndrome. However, the involvement of extraocular muscles with ragged-red fibers was demonstrated in MELAS and MERRF.14 Peripheral neuropathy has been described in a number of cases of mitochondrial myopathy, mainly in KSS and MERRF.1517 Only a few cases of MELAS had peripheral nerve damage.18 The presented case showed full-blown MELAS syndrome and characteristic pictures of CPEO. In the past few years, an increasing number of studies have been devoted to molecular analysis of the mtDNA from patients with various mitochondrial diseases. Largescale deletions ranging from 1 to 8 kb were found in the muscle mtDNA of patients with KSS,19,20 while a point mutation at nucleotide position 3243 and another one at position 3271 in the mtDNAs of patients with the MELAS syndrome were recently identified.21,22 In the previous three cases of overlapping syndrome, no molecular anal¬ ysis of mtDNA was reported. Recently, another article re¬ vealed a major deletion in mtDNA in two patients with combined features of KSS and MELAS syndrome.23 In contrast, from our results of a point mutation at the 3243rd nucleotide position of mtDNA, we suggest that ophthal¬ moplegia can manifest in MELAS patients. We believe that molecular analysis will provide fundamental differences was 1989;112:1231-1260. 8. Pavlakis SG, Phillips PC, DiMauro S, DeVivo DC, Rowland LP. Mito- chondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes: a distinctive clinical syndrome. Ann Neurol. 1984;16:481-488. 9. Driscoll PF, Larsen PD, Gruber AB. MELAS syndrome involving a mother and two children. Arch Neurol. 1987;44:971-973. 10. Fritz T, Wessel K, Weidle E, Lenz G, Peiffer J. Anesthesia for eye surgery in cases of mitochondrial encephalomyopathy. Klin Mbl Augenheilkd. 1988;193:174-178. 11. Dest'ee A, Martin JJ, Muller JP, et al. Mitochondrial myopathy: encephalopathy with lactic acidosis and cerebral infarct. Rev Neurol. 1989; 145:37-48. 12. K\l=u"\chleM, Brenner PM, Engelhard A, Naumann GOH. Ocular symptoms in MELAS syndrome. Klin Mbl Augenheilkd. 1990;197:258-264. 13. Drachman DA. Ophthalmoplegia plus: the neurodegenerative disor- ders associated with progressive external ophthalmoplegia. Arch Neurol. 1968;18:654-674. 14. Takeda S, Ohama E, Ikuta F. Involvement of extraocular muscle in mitochondrial encephalomyopathy. Acta Neuropathol. 1990;80:118-122. 15. Yiannikas C, McLeod JG, Pollard JD, Baverstock J. Peripheral neuropathy associated with mitochondrial myopathy. Ann Neurol. 1986;20:249\x=req-\ 257. 16. Pezeshkpour G, Krarup C, Buchthal F, DiMauro S, Bresolin N, McBurney J. Peripheral neuropathy in mitochondrial disease. J Neurol Sci. 1987;77:285-304. 17. Mizusawa H, Watanebe M, Kanazawa I, et al. Familial mitochondrial myopathy associated with peripheral neuropathy: partial deficiencies of complex I and complex IV. J Neurol Sci. 1988;86:171-184. 18. Ihara Y, Namba R, Kuroda S, Sato T, Shirabe T. Mitochondrial encephalomyopathy (MELAS): pathological study and successful therapy with coenzyme Q10 and idebenone. J Neurol Sci. 1989;90:263-271. 19. Holt IJ, Harding AE, Morgan-Hughes JA. Deletions of muscle mitochondrial DNA in patients with mitochondrial myopathies. Nature. 1988; 331:717-719. 20. Moraes CT, DiMauro S, Zeviani M, et al. Mitochondrial DNA deletions in progressive external ophthalmoplegia and Kearns-Sayre syndrome. N Engl J Med. 1989;320:1293-1299. 21. Kobayashi Y, Momoi MY, Tominaga K, et al. A point mutation in the mitochondrial tRNALeu (UUR) gene in MELAS (mitochondrial myopathy, en- cephalopathy, lactic acidosis and stroke-like episodes). Biochem Biophys Res Commun. 1990;173:816-822. 22. Goto YI, Nonaka I, Horai S. A new mtDNA mutation associated with mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS). Biochim Biophys Acta. 1991;1097:238-240. 23. Zupanc ML, Moraes CT, Shanske S, Langman CB, Ciafaloni E, DiMauro S. Deletion of mitochondrial DNA in patients with combined features of Kearns-Sayre and MELAS syndromes. Ann Neurol. 1991;29: 680-683. Downloaded From: http://archneur.jamanetwork.com/ by a University of California - San Diego User on 06/09/2015