Journal of Neurology, Neurosurgery, and Psychiatry 1987;50:786-788 Short report Mirror-writing and reversed repetition of digits in a right-handed patient with left basal ganglia haematoma LIE-GAN CHIA, MARCEL KINSBOURNE* From the Neurology Section, Veterans General Hospital, Taichung, Taiwan, and the Department ofBehavioral Neurology,* Eunice Kennedy Shriver Center, Massachusetts, USA SUMMARY A 57 year old right-handed Chinese man sustained a left basal ganglia haemorrhage resulting in speech disorder and right hemiplegia. He mirror-wrote with his left hand and during speech recovery repeated digits in reverse sequence. The abnormal right to left directionality possibly reflected release of right basal ganglia from left-sided control. "Mirror-writing" is a well recognised occasional finding after acute left cerebral damage as well as in young and developmentally delayed children.' The underlying neuroanatomy is not clear, however. We report an illustrative case with a well defined and isolated left basal ganglia lesion, which shows that damage in this area is sufficient (and perhaps necessary) to cause mirror-writing and reversed repetition of digits, which has not previously been reported. his home address, he reversed the door number "523" to "3-2-5." Asked to repeat other digit sequences, he also reversed their order: for example, hearing or seeing "4-3-5," he repeated "5-3-4." However, he did not reverse the order of connected spoken words; given the phrase "ni-hen-hao," indicating "you are very good," he did not reverse it. His hemiplegia was improved, but he still could not use his right hand to write. He now could write normal script with his left hand, but some words were still mirror-written (fig 2c). He was not observed to use tools in reverse directionality in the interim. Two years after the onset, the brain CT scan was similar to the previous one. Although his right arm could move, the right hand remained paretic. He was still writing with the left hand. But mirror-writing was no longer evident (fig 2D), and he now found mirror-writing very difficult when asked to do it. His speech was much improved, and he now never reversed the order of spoken digits. Case Report A 57 year old right-handed Chinese man suddenly developed slurred speech and right hemiplegia. On admission to hospital the same day, his blood pressure was 160/110 mm Hg. He had no speech output, but good comprehension. There was right spastic hemiplegia, but no hemianopsia or alexia. CT scan revealed a haematoma with surrounding oedema in the left basal ganglia (fig 1, left). Because he could not speak, he communicated by writing. This he spontaneously did in mirror-writing (fig 2b), which he had never previously been known to do. When, on request, he tried to write in the normal direction, he found this very difficult. There were no left-handers in his family. Ten months later, CT of the brain showed a low density area in the left basal ganglia region, resulting from absorption of the haematoma (fig 1, right). His speech was grammatical and slow, with a severe dysarthria. When he stated @.?~~~~~~~~~~~~~J. 'k. O., ::-i AM Address for reprint requests: Dr Chia, Neurology Section, Veterans General Hospital, Taichung, Taiwan (400). Received 25 March 1986 and in revised form 13 August 1986. Accepted 23 September 1986 Fig 1 Left: CTshowing patient's intracerebral haematoma on left basal ganglia at onset ofillness. Right: CTshowing a low density with absorption ofhaematoma on left basal ganglia ten months after onset ofillness. 786 Mirror-writing and reversed repetition ofdigits in a right-handed patient with left basal ganglia haematoma 787 For both, our patient is a test case. (1) Had the conventional direction of action been right-to-left, that too would be subject to reversal. Inherent in Chinese script is not only left-to-right directionality for characters, which was reversed, but also right-to-left directionality for columns. This was not reversed. (2) The reversal tendency is rather nonspecific, in that any activity with a practised, unidirectional component should be affected. Indeed, associated mirror reading is often reported. But our patient did not mirror read (that is, he did not read the columns left-toright). Nor did he exhibit reversed directionality in activities of daily living. We conclude that the above-mentioned hypotheses are not supported in the present case. His mirror writing appears to have arisen from a programming flaw I I W'1 specific to one component of writing. Left-to-right action was reversed, whereas right-to-left action and Fig 2 (A) Normal script (It means "Veterans General configuration remained intact. We attributed the seHospital Taichung Neurology Section Lee San"). (B) mirror-writing, at onset of illness. (C) normal script lective reversal of left-to-right action to the left basal intermixed withfew mirror written words (indicated by ganglia damage and predict that in cases of right asterisk), ten months after onset ofillness. (D) normal script, basal ganglia damage the opposite element of the ditwo years after onset of illness. rectional dissociation will be found, selective reversal of the right-to-left tendency for columns. The case of closed head injury reported by Streifler Discussion and Hofman' is consistent with this expectation Individual Chinese characters are normally written (though anatomical verification is lacking). He wrote from left to right and our patient reversed this direc- Hebrew in reverse (that is, from left to right), but tion. Their sequence, however, is vertical, and right to maintained Western script in its left-to-right direcleft, and this was unaffected. Our patient's mirror- tion. The present case offers more direct evidence for the writing was not accompanied by any abnormality in reading. However, as Chinese is read vertically, there locus of the damage than the older case reports were was no scope for mirror-reading to appear. We could able to. Also, the case of Heilman et al5 was not only find no previously reported cases of mirror-writing in a left-hander (and indeterminate with respect to brain Chinese after acute brain-lesions, but the case seems organisation), but also had previously undergone left comparable to reported instances of mirror-writing in thalamotomy. His CT scan was normal. The subcorEnglish following acute left cerebral damage' such as tical location of the damage in our patient perhaps the case of Heilman et al.' supports a directional theory3 better than one inMirror-writing is not uncommon in young and de- voking mirror-image engrams.2 7 Each striatum is velopmentally handicapped children, perhaps partic- known to direct action contralaterally. Rats with uniularly in the presence of left-handedness (although lateral basal ganglia lesions circle towards the side of such individuals produce mirror-writing with either the lesion contralaterally, with basal ganglia stimuhand). Both for the developmental2 and the acquired3 lation ipsilaterally.7 Asymmetries are accentuated afinstance, a theory of double representation of the mo- ter callosal section,8 suggesting that the basal ganglia tor act has been proposed. In addition to being repre- are normally in reciprocal inhibitory interaction in sented in the dominant hemisphere, a representation the control of turning tendencies. We therefore sugin mirror image is hypothesised in the other hemi- gest that in our patient the element of left to right sphere (the latter taking control of behaviour inter- directionality in skilled writing performance relied on mittently when dominance is "incomplete," or a greater left than right basal ganglia activation. After continuously for a time when the dominant hemi- left-sided damage, activation balance reversed and so sphere is damaged). Evidence from interocular trans- did the direction of writing. As the large haematoma fer in monkeys with sectioned optic chiasm is cited in was absorbed in the left basal ganglia, normally disupport.4 Alternatively, the mirror tendency has been rected writing with the left hand emerged. This might viewed as a directional confusion, as illustrated in a be due to functional compensation by the normal tisreport of a patient who also had a spatial deficit.5 sue surrounding the lesion. Implicit in both points of view are two corollaries. The speech disturbance induced by left basal gan- I"''I1 788 glia lesion in this case was of the type described as subcortical Broca's aphasia.9 The patient's unique tendency to reverse digit sequences that he was asked to repeat also fits more comfortably with a directional interpretation. The patient perhaps visualised the digit names in the lateral direction, then read them out from his imagery in the other direction. The reversal of spoken digits disappeared in parallel with his mirror writing. The alternative theory that the writing act in toto is represented bilaterally in mirror-image2 3 becomes less attractive once this has to be attributed to the basal ganglia level. Disordered letter formation (apraxic agraphia) is attributed to left parietal lobe dysfunction,10 and mirror-writing is not cited as an associated finding. It seems more likely that whereas the cerebral cortex is involved in letter formation, the basal ganglia concurrently contribute the direction of writing. We thank Dr WC Shen, Chief of Neuroradiology in VGH-Taichung, for his review of the CTs, and Dr P Alexander for his review of this paper. References 1 Critchley M. Mirror-Writing. London: Kegan Paul, Trench, Trubner, 1928. Chia, Kinsbourne 2 Orton ST. Specific reading disability-strephosymbolia. JAMA 1928;90:1095-9. 3 Corballis MC, Beale IL. The Psychology of Left and Right. Hillsdale, NJ: Erlbaum, 1976. 4 Noble J. Paradoxical interocular transfer of mirrorimage discriminations in the optic chiasm sectioned monkey. Brain Res 1968;10:127-51. 5 Heilman KM, Howell G, Valenstein E, Rothi L. Mirror reading and writing in association with right-left spatial disorientation. J Neurol Neurosurg Psychiatry 1980;43:774-80. 6 Streifier M, Hofman S. Sinistral mirror writing and reading after brain concussion in a bi-systemic (orientaloccidental) polyglot. Cortex 1976;12:356-64. 7 Zimmerberg B, Glick SD. Changes in side preference during unilateral electrical stimulation of the caudate nucleus in rats. Brain Res 1975;86:335-8. 8 Glick SD, Crane AM, Jerussi TP, Flusher LN, Green JP. Functional and neurochemical correlates of potentiation of striatal asymmetry by callosal section. Nature 1975;254:616-7. 9 Naeser MA, Alexander MP, Helm-Estabrooks N, Levine HL, et al. Aphasia with predominantly subcortical lesion sites: description of three capsular/putaminal aphasia syndromes. Arch Neurol 1982;39:2-14. 10 Hecaen H, Angelergues R, Douzenis JA. Les agraphies. Neuropsychologia. 1963;1:179-208.