Abstract
Electroencephalograms (EEGs) and evoked potentials (EPs) were studied in 43 patients with mitochondrial myopathies. Abnormalities were found most frequently in patients who presented predominantly or exclusively with central nervous system (CNS) dysfunction (abnormal EEGs in 18 of 21 patients, abnormal EPs in 9 of 11 patients). However, of patients presenting with ocular myopathy or proximal muscle weakness who had little or no CNS involvement clinically, 8 of 22 had abnormal EEGs and 5 of 10 had abnormal EPs, suggesting that electrophysiological tests are of value in demonstrating subclinical CNS disease in mitochondrial myopathy, although the abnormalities are not specific.
Similar content being viewed by others
References
Battaglia A (1981) Electroencephalogram, electroretinogram and visual evoked potential studies in opthalmoplegia plus. Acta Neurol Ital 3:721–727
Berkovic SF, Andermann F, Carpenter S, Wolfe LS (1986) Progressive myoclonus epilepsies: specific causes and diagnosis. N Engl J Med 315:296–305
Dawson GD (1947) Investigations on a patient subject to myoclonic seizures after sensory stimulation. J Neurol Neurosurg Psychiatry 10:141–162
DiMauro S, Bonilla E, Zeviani M, Nakagawa M, De Vivo DC (1985) Mitochondrial myopathies. Ann Neurol 17:521–538
Direke M, Campbell G (1975) Further studies on progressive external ophthalmoplegia. Acta Neurol Scand 51:245–248
Egger J, Lake BD, Wilson J (1981) Mitochondrial cytopathy: a multisystem disorder with ragged red fibres on muscle biopsy. Arch Dis Child 56:741–752
Fukuhara N, Tokiguchi S, Shirakawa K, Tsubaki T (1980) Myoclonus epilepsy associated with ragged-red fibres (mitochondrial abnormalities): disease entity or syndrome? Lightand electron-microscopic studies of two cases and review of literature. J Neurol Sci 47:117–133
Hammans SR, Sweeney MG, Brockington M, Morgan Hughes JA, Harding AE (1991) Mitochondrial encephalopathies: molecular genetic diagnosis from blood samples. Lancet 337:1311–1313
Harden A, Pamplighone G, Battaglia A (1982) Mitochondrial myopathy or mitochondrial disease? EEG, ERG, VEP studies in 13 children. J Neurol Neurosurg Psychiatry 45:627–633
Holt IJ, Harding AE, Cooper JM, et al (1989) Mitochondrial myopathies: clinical and biochemical features of 30 patients with major deletions of muscle and mitochondrial DNA. Ann Neurol 26:699–709
Jasper HH (1958) Report of the committee on methods of clinical examination in electroencephalography. Electroencephalogr Clin Neurophysiology 10:370–375
Kiruyama M, Umezaki H, Fukuda Y, Osame M, Koike K, Tateishi J, Igata A (1984) Mitochondrial encephalomyopathy with lactate-pyruvate elevation and brain infarctions. Neurology 34:72–77
Morgan-Hughes JA (1986) Mitochondrial disease. Trends Neurosci 9:15–19
Morgan-Hughes JA, Hayes DJ, Clark JB, Landon DN, Swash M, Stark RJ, Rudge P (1982) Mitochondrial encephalomyopathies: biochemical studies in two cases revealing defects in the respiratory chain. Brain 105:553–582
Obeso JA, Rothwell JC, Marsden CD (1985) The spectrum of cortical myoclonus. Brain 108:193–224
Pavlakis SG, Phillips PC, DiMauro S, De Vivo DC, Rowland LP (1984) Mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes: a distinctive clinical syndrome. Ann Neurol 3:455–458
Petty RKH, Harding AE, Morgan-Hughes JA (1986) The clinical features of mitochondrial myopathy. Brain 109:915–938
Rosing HS, Hopkins LC, Wallace DC, Epstein CM, Weidenheim K (1985) Maternally inherited mitochondrial myopathy and myoclonic epilepsy. Ann Neurol 17:228–237
Rowland LP, Hays AP, DiMauro S, De Vivo DC, Behrens M (1983) Diverse clinical disorders associated with morphological abnormalities of mitochondria. In: Scarlato G, Cerri C (eds) Mitochondrial pathology in muscle disease. Piccin, Padua, pp 142–158
Shapira Y, Harel S, Russell A (1977) Mitochondrial encephalomyopathies: a group of neuromuscular disorders with defects in oxidative metabolism. Isr J Med Sci 13:161–164
Shibasaki H, Yamashita Y, Kuroiwa Y (1978) Electroencephalographic studies of myoclonus. Myoclonus-related cortical spikes and high amplitude somatosensory evoked potentials. Brain 101:447–460
Shoffner JM, Lott MT, Lezza AMS, Seibel P, Ballinger SW, Wallace DC (1990) Myoclonic epilepsy and ragged-red fibre disease (MERRF) is associated with a mitochondrial DNA tRNAlys mutation. Cell 61:931–937
So N, Berkovic S, Andermann F, Kuzniecky R, Gendron D, Quesney LF (1989) Myoclonus epilepsy and ragged red fibre (MERRF). 2. Electrophysiological studies and comparison with other progressive myoclonus epilepsies. Brain 112:1261–1270
Tartara A, Manni R, Scelsi R, Piccolo G, Cosi V (1983) Electroencephalographic findings in patients with chronic progressive external opthalmoplegia. Ital J Neurol Sci 4:459–462
Truong DD, Harding AE, Scaravilli F, Smith SJM, MorganHughes JA, Marsden CD (1990) Movement disorders in mitochondrial myopathies: a study of nine cases with two autopsy studies. Mov Disord 5:109–117
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Smith, S.J.M., Harding, A.E. EEG and evoked potential findings in mitochondrial myopathies. J Neurol 240, 367–372 (1993). https://doi.org/10.1007/BF00839969
Received:
Revised:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00839969