figure, B). The proportion of heteroplasmy was estimated by Genescan analysis (ABI 377) of fluorescently labeled PCR restriction fragment length polymorphism products as previously described.2 This mutation was absent in 105 healthy controls. Both ND5 gene changes were homoplasmic and present in controls. Single-fiber PCR studies were performed to investigate the relationship between the mutant G4810A mtDNA load and RRFs at the level of single muscle fiber (see figure, C). The mean proportion of the mutant mtDNA in the RRFs was 84.27% (SEM ⫽ 3.66, n ⫽ 15) and that in the non-RRFs was 7.15% (SEM ⫽ 1.91, n ⫽ 14) (p ⬍ 0.0001, independent sample t test). Discussion. We describe a patient with mitochondrial myopathy and isolated complex I deficiency presenting with marked exercise intolerance and myalgia. The ophthalmoplegia was only first detectable almost 40 years after the initial presentation with exercise intolerance. Exercise intolerance is increasingly recognized as the sole feature of mitochondrial respiratory chain disease in association with nonsense mtDNA mutations (see table E-1 on the Neurology Web site at www.neurology.org). Such mutations are confined to skeletal muscle and may represent spontaneous somatic mutations. Such patients often have a marked inability to engage in persistent exercise but may have minimal weakness on examination. We identified an unreported G4810A mutation in the mitochondrial ND2 gene that fulfilled the criteria for pathogenicity: First, it was a nonsense mutation resulting in a change from tryptophan to a stop codon at position 114. This change predicts a truncated ND2 protein with the loss of 233 amino acids from the C terminus of the ND2 polypeptide. Second, the mutation was heteroplasmic in muscle and was absent from blood. Third, it was absent in control samples. Fourth, single-fiber PCR analysis revealed a positive correlation between the proportion of mutant mtDNA and abnormal muscle fiber morphology. Fifth, the muta- tion was consistent with the biochemical finding of the complex I defect in muscle. This mutation significantly truncates ND2 and is predicted to have important deleterious structural and functional consequences. However, the measured defect in complex I is relatively mild. This may be a reflection of the assay used or may indicate a compensatory mechanism is present. These findings add to the evidence that sporadic somatic nonsense mutations in mtDNA, confined to skeletal muscle, particularly associate with exercise intolerance. Acquired stuttering secondary to callosal infarction moshi (if), she said “mo-mo-mo-mo-shi.” Instead of ohiruni (a nap), she said “ohi-ohi-rune.” When she read, repetition occurred frequently. However, her voice volume did not change. She achieved the intended sound relatively correctly, only to repeat it. Although she showed adaptation (decreased stuttering on successive oral readings of the same material), she was not fluent during singing. The speech disturbances did not fluctuate. Laboratory studies. Hypercholesterolemia (319 mg/dL) was present. Imaging studies. T2-weighted brain MRI (GE-Signa, 1.5 T, repetition time/echo time 3,000/102) demonstrated a high intensity signal in the body of the CC (arrow, figure, A and B). Spotty high intensity signals were also present in the deep white matter. The CC lesion showed a low-intensity signal on T1-weighted imaging. After 1 year, MRI showed reduced lesion size and partial atrophy of the CC (figure, C and D). Neuropsychological testing. Eight weeks after the stroke, the patient’s score on the Mini-Mental State Examination was 30/30. On Wechsler Adult Intelligence Scale–Revised, verbal IQ was 101, nonverbal IQ was 110, and full-scale IQ was 106. Tests for leftsided tactile anomia and left-sided ideomotor apraxia, left-sided agraphia, left-sided visual anomia, left-sided deafness, alien hand sign, and frontal gait disturbances were negative. The patient was tested with the Japanese version of the Western Aphasia Battery. She made no errors on subsets for auditory comprehension, repetition, naming, reading, and writing. Her score on the Token Test was perfect. She completed 40 tests of buccofacial praxis without error. The patient was started on ticlopidine, 200 mg/day. Discussion. A disorder characterized by stuttering-like, repetitive speech has been reported after infarctions in the SMA, paramedian thalami and midbrain, left and right parietal lobes, and left striatocapsular area.2 Lesions in the deep white matter below the SMA, disrupting the interhemispheric connections coursing through the body of the CC, contribute to an affective-prosodic deficit.4 A few cases of dysprosody following a lesion in the CC have been reported. For example, dysprosody and speech delay have followed anterior callosotomy in patients with intractable epilepsy and crossed cerebral dominance.5 In a case of subarachnoid hem- T. Hamano, MD, PhD; S. Hiraki, MD, PhD; Y. Kawamura, MD, PhD; M. Hirayama, MD, PhD; T. Mutoh, MD, PhD; and M. Kuriyama, MD, PhD Stuttering is defined as an impairment of continuous utterance. The cause of developmental stuttering remains obscure despite many studies of its possible neurologic origin.1 The appearance of stuttering after adult-onset brain damage has received attention because this sequence of events may provide clues to the mechanisms of developmental stuttering.2 The corpus callosum (CC) constitutes the largest nerve fiber tract in the human brain. Its anterior portion carries prefrontal fibers; its middle portion, fibers from the motor cortex, including the supplementary motor area (SMA), as well as from somatosensory and auditory cortex; and its posterior portion, fibers from the occipital and temporal lobes.3 Its chief function is interhemispheric integration. It is widely believed that an acquired callosal lesion causes apraxia and agraphia in the left hand. However, it is not commonly accepted that callosal lesions cause speech disturbances. We report an unusual manifestation of a small infarction in the body of the CC: stuttering without disconnection syndrome. Case report. A 77-year-old woman with a junior-high-school education suddenly developed dizziness, nausea, and speech disturbances. She was admitted to the hospital on the following day. The patient was right-handed for writing, throwing a ball, and using chopsticks. She preferred the right foot for kicking a ball, the right eye for looking through a telescope, and the right ear for monaural listening. She had taken medication for hypertension for 10 years. She had no personal or family history of dysfluency. Physical examination. Blood pressure was 140/90 mm Hg. Pulse was regular at 82/minute. General findings were unremarkable. Neurologic examination. The patient was alert and had normal mentation. Cranial nerve examination was normal. There was no weakness. Deep tendon reflexes were brisk. Sensory and cerebellar functions were normal. The patient’s speech lacked fluency. She often repeated an initial syllable or phoneme. For example, when she tried to say 1092 NEUROLOGY 64 March (2 of 2) 2005 From the Department of Molecular Neuroscience (Drs. Pulkes, Liolitsa, and Hanna), Centre for Neuromuscular Disease (Dr. Hanna), and Department of Neurochemistry (Drs. Hargreaves and Heales), Institute of Neurology, London, and Department of Neurology (Dr. Wills), University Hospital of Nottingham, UK. Supported by the Brain Research Trust, UK, University College Hospitals Special Trustees, and the UCL MRC Cooperative Grant “Mitochondria in Health and Disease.” Received August 11, 2004. Accepted in final form November 15, 2004. Address correspondence to Dr. M.G. Hanna, Centre for Neuromuscular Disease and Department of Molecular Neuroscience, Division of Neurology, Institute of Neurology, Queen Square, London WC1N 3BG, UK; e-mail: m.hanna@ion.ucl.ac.uk Copyright © 2005 by AAN Enterprises, Inc. References 1. Andreu AL, Hanna MG, Reichmann H, et al. Exercise intolerance due to mutations in the cytochrome b gene of mitochondrial DNA. N Engl J Med 1999;341:1037–1044. 2. Hanna MG, Nelson IP, Rahman S, et al. Cytochrome c oxidase deficiency associated with the first stop-codon point mutation in human mtDNA. Am J Hum Genet 1998;63:29 –36. Figure. Sagittal (A) and axial (B) sections from T2-weighted brain MRI (GESigna, 1.5 T, repetition time/echo time 3,000/102). The study demonstrates a high intensity signal in the body of the corpus callosum (CC) (arrow, A and B). Spotty high intensity signals are also present in the deep white matter. Sagittal (C) and axial (D) sections from T2weighted brain MRI of the patient 1 year after onset. The lesion is smaller and the CC is partially atrophied. orrhage, a lesion in the anterior four-fifths of the CC, including the body, caused dysprosody with left limb apraxia and alien hand sign. The authors suspected that the CC plays an important role in the programming of prosody by providing interhemispheric connections.6 Acquired stuttering and left hand apraxia following infarction in the body of the CC have also been reported.7 The body was a commonly affected portion of the CC in reported cases of acquired stuttering.6,7 Destruction of SMA fibers in the body of the CC may contribute to the development of stuttering. Our patient showed that even a CC lesion that is not large enough to induce a callosal disconnection syndrome may be the source of acquired stuttering. Acknowledgment The authors thank Dr. M. Sugishita, Department of Cognitive Neuroscience, Faculty of Medicine, University of Tokyo, and Dr. S. Ito, Department of Neurology, for helpful comments, and Y. Kida, Department of Rehabilitation, Fukui General Hospital, and Y. Iwasa, Department of Logopedics, Fukui Rehabilitation Hospital, for performing mental tests. From the Second Department of Internal Medicine (Drs. Hamano, Hirayama, Mutoh, and Kuriyama), Department of Radiology (Dr. Kawamura), Faculty of Medical Sciences, University of Fukui; and Department of Internal Medicine (Dr. Hiraki), Fukui Rehabilitation Hospital, Japan. Supported by a grant from the Ministry of Education, Cultures, Sports, Science and Technology of Japan (to T.H. and T.M.). Received July 28, 2004. Accepted in final form November 19, 2004. C2 myelitis presenting with neuralgiform occipital pain Christopher J. Boes, MD Neuralgiform occipital pain can be secondary to occipital neuralgia or great auricular neuralgia. Occipital neuralgia is characterized by jabbing pain in the distribution of the greater or lesser occipital nerves or of the third occipital nerve, sometimes associated with diminished sensation in the affected area.1 The affected nerve is often tender, and the pain is eased temporarily by local Address correspondence and reprint requests to Dr. T. Hamano, Second Department of Internal Medicine, Faculty of Medical Sciences, University of Fukui, 23-Shimoaizuki, Matsuoka-cho, Yoshida-gun, Fukui 910 –1193, Japan; e-mail: tada_hamano@yahoo.co.jp Copyright © 2005 by AAN Enterprises, Inc. References 1. Braun AR, Varga M, Stager S, et al. Altered patterns of cerebral activity during speech and language production in developmental stuttering. An H215O positron emission tomography study. Brain 1997;120:761–784. 2. Ciabarra AM, Elkind MS, Roberts JK, Marshall RS. Subcortical infarction resulting in acquired stuttering. J Neurol Neurosurg Psychiatry 2000;69:546 –549. 3. Pandya DN, Seltzer B. The topography of commissural fibers. In: Lepre F, Ptito M, Jasper HH, eds. Two hemispheres— one brain: functions of the corpus callosum. New York: Alan R. Liss, 1986;47–73. 4. Ross ED, Thompson RD, Yenkosky J. Lateralization of affective prosody in brain and the callosal integration of hemispheric language functions. Brain Lang 1997;56:27–54. 5. Sass KJ, Novelly RA, Spencer DD, Spencer SS. Postcallosotomy language impairments in patients with crossed cerebral dominance. J Neurosurg 1990;72:85–90. 6. Klouda GV, Robin DA, Graff-Radford NR, Cooper WE. The role of callosal connections in speech prosody. Brain Lang 1988;35:154 –171. 7. Hagiwara H, Takeda K, Saito F, Shimizu T, Bando M. A case of callosal apraxia without agraphia and acquired stuttering associated with callosal infarction. Rhinsho Shinkeigaku 2000;40:605– 610. anesthetic blockade.1 Occipital neuralgia can be caused by injury, inflammation, or compression of the greater occipital nerve.2 C1 to C2 arthrosis can mimic occipital neuralgia.3 Patients with occipital neuralgia secondary to an upper cervical cord cavernous angioma2 and neurosyphilis4 have been reported. We report another unusual cause of neuralgiform occipital pain. Case report. A 55-year-old left-handed man received tetanus/ diphtheria toxoid, hepatitis A, and typhoid vaccinations in preparation for a trip from America to Ecuador. Seven days later, he noted episodes of shooting pain in the right occipital region, superior and posterior to the right ear and rarely in the right anterior March (2 of 2) 2005 NEUROLOGY 64 1093 Acquired stuttering secondary to callosal infarction T. Hamano, S. Hiraki, Y. Kawamura, et al. Neurology 2005;64;1092-1093 DOI 10.1212/01.WNL.0000154472.51190.FB This information is current as of March 21, 2005 Updated Information & Services including high resolution figures, can be found at: http://www.neurology.org/content/64/6/1092.full.html References This article cites 8 articles, 2 of which you can access for free at: http://www.neurology.org/content/64/6/1092.full.html##ref-list-1 Subspecialty Collections This article, along with others on similar topics, appears in the following collection(s): All Cerebrovascular disease/Stroke http://www.neurology.org//cgi/collection/all_cerebrovascular_disease_ stroke Infarction http://www.neurology.org//cgi/collection/infarction Stuttering http://www.neurology.org//cgi/collection/stuttering Permissions & Licensing Information about reproducing this article in parts (figures,tables) or in its entirety can be found online at: http://www.neurology.org/misc/about.xhtml#permissions Reprints Information about ordering reprints can be found online: http://www.neurology.org/misc/addir.xhtml#reprintsus Neurology ® is the official journal of the American Academy of Neurology. 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