Journal of Neurology, Neurosurgery, and Psychiatry 1989;52:792-794 Short report Cheiro-oral syndrome with bilateral oral involvement: a study of pontine lesions by high-resolution magnetic resonance imaging SADAYUKI MATSUMOTO,* SHIZUMA KAKU,* MASAHIRO YAMASAKI,* TERUKUNI IMAI,* HIDEHIKO NABATAME,I MASAKUNI KAMEYAMAI From the Department of Neurology, Kitano Hospital and Neurological Center,* Tazuke-Kohukai Medical Institute, Osaka, Department of Neurology, Faculty of Medicine,t Kyoto University, Kyoto, Sumitomo Hospital,: Osaka, Japan SUMMARY Two cases of unusual cheiro-oral syndrome due to small pontine haemorrhage are described, in which both sides of the mouth were involved in the initial stage. High resolution magnetic resonance imaging revealed a small lesion at the paramedian pontine tegmentum in both cases and suggested involvement of the medial portion of the medial lemniscus. In 1914 Sitting' first described a sensory defect observed around the corner of the mouth and on the palm on the same side of the body, the cheiro-oral syndrome. The syndrome is usually considered to be due to a small lesion in the contralateral post-central gyrus of the parietal lobe' or to a lesion in the thalamus2 limited to the inferior medial portion of the ventral posterolateral nucleus and the lateral part of the ventral posteromedial nucleus of the thalamus.3 Recently, some cases of this syndrome associated with brainstem lesions have been reported.9 We report two cases of small pontine haemorrhages showing an unusual cheiro-oral syndrome, in which both sides of the mouth were involved. Magnetic resonance imaging (MRI) revealed details of the lesion in the pontine tegmentum in both cases. Case reports Case I A hypertensive 38 year old man suddenly felt dizzy followed by numbness in his lower right face and his right hand and was admitted to hospital on the same day. He remained alert and was not dysarthric. Dysaesthesia and mild sensory defects of pain, temperature and tactile sensations were found all around his mouth, on the oral mucosa and on his right palm. There was no sign of either weakness or cerebellar ataxia. Sensory defects of both sides of the mouth persisted only for three days, after which the left side of the mouth was affected. In a month all sensory defects had disappeared. CT detected a small haematoma in the left paramedian tegmentum of the upper pons and the midbrain, and an old small infarct in the left putamen. MRI using a 1 5-T superconducting unit (Sigma System, General Electric, Milwaukee) demonstrated the small lesion precisely and the sagittal image delineated the rostro-caudal extension (fig 1). Case 2 A hypertensive 47 year old woman on renal dialysis suddenly felt headache, nausea and numbness around her mouth and right fingers. On admission, she was alert but slightly dysarthric. Her pupils were slightly anisocoric but promptly reactive. Dysaesthesia around both sides of her mouth and on her right fingers persisted, but no objective hypaesthesia was detected. Right hemiparesis and bilateral cerebellar ataxia were noted, and the Babinski sign was present on the right side. On the ninth hospital day, numbness around the mouth remained only on the right side and disappeared completely in a month. CT revealed a haematoma in the left paramedian region of the mid-pons. MRI disclosed in more detail two small lesions involving the paramedian pontine tegmentum and the dorsal basis pontis (fig 2). No other lesions were found in the thalamus and parietal lobe. Address for reprint requests: Dr Sadayuki Matsumoto, Bluestone Laboratory of the Division of Neuropathology, Montefiore Medical Center, 111 East 210th Street, Bronx, New York 10467, USA. Discussion Received 30 September 1988 and in revised form 30 December 1988. The cheiro-oral syndrome has so far been reported Accepted 1O January 1989 associated with small lesions of the parietal post- 792 793 Cheiro-oral syndrome with bilateral oral involvement: a study ofpontine lesions by high-resolution MRI W.: :: . -A,;.: -s Fig V, A %w 1% (Case 1) (a) Axial T2-weighted image. (spin echo, TR: 2000 ms, TE: 80 ins). A small low-intensity area is (b) Sagittal Ti-weighted image. (partial saturation located at the paramedian tegmentum of the upper pons (arrow). recovery. TR: 400 ms, TE: 25 ins) A slit-like low intensity area is located at the tegmentum in the middle to upper pons (arrow). central gyrus,' stem thalamus," and, recently, in the brain- tegmentumi"9 The combined unilateral sensory sensory cortex of the parietal post-central gyrus. In the brainstem that the lesions, clinical and CT findings syndrome is due disturbance of the hand and the corner of the mouth is suggest thought to be derived from the close somatotopical involvement of the medial lemniscus.79 localisation of the thalamic sensory nuclei and the MRI studies Fig 2 to partial In our cases, clearly delineated a small lesion at the (Case 2) (a) Axial T2-weighted image. (spin echo, TR: 2000 ins, TE: 40 ins) Two low-intensity areas are tegmentwn (black arrow). (b) Sagittal located at the basis of the pons (white arrow) and at the paramedian pontine at Ti-weighted image (partial saturation recovery. TR: 400 ms, TE: 25 ins) Two slit-like low intensity areas are noted the base (white arrow) and tegmentum (black arrow) of the middle pons. 794 Matsumoto, Kaku, Yamasaki, Imai, Nabatame, Kameyama Herbert M Dembitzer for their advice and which in case, each paramedian pontine tegmentum was probably responsible for the sensory defects. The encouragement in preparing this manuscript. basal pontine lesion in case 2 was probably the cause of References paresis and ataxia. It is noteworthy that both sides of the mouth were involved at the initial stages. No I Sitting 0. Klinische Beitrage zur Lehre von der Lokalisation der sensiblen Rindenzentren. Prager Med Wochenschr previous cheiro-oral syndrome case has been 1914;45:548-50. associated with such a sensory distribution as far as we 2 Garcin R, Lapresle J. Syndrome sensitif de type thalamique et a are aware. topographie cheiro-orale par lesion localis6e du thalamus. Rev The clinico-anatomical basis for the temporary Neurol (Paris) 1954;90:124-9. bilateral involvement of the mouth is unknown. One 3 Garcin R, Lapresle J. Deuxi6me observation personnele de syndrome sensitif de type thalamique et a topographie cheiropossibility is that the haematomas in the acute stage orale par lesion localisee du thalamus. Rev Neurol (Paris) may have transiently impaired the medial portion of 1960;103:474-81. the contralateral medial lemniscus, where the secon- 4 Strauss H. Ober Sensibilitiitsstorungen an Hand und'Gesicht. Geschmacksstorungen und ihre lokalisatorische Bedeutung. dary sensory fibres from the mouth are located most Monatsschr Psychiat Neurol 1925;58:265-76. medially and close to the other side.'" The second 5 Araga S, Fukada M, Kagimoto H, Takahashi K. Pure sensory possibility is that the uncrossed fibres of the dorsal stroke due to pontine haemorrhage. J Neurol 1988;235:116-7. trigeminothalamic tract'0 and the medial portion of 6 Hashiguchi K, Igata A. A case of primary pontine hemorrhage with cheiro-oral syndrome. Neurol Med (Tokyo) 1976;5:79-80. the medial lemniscus may be involved in the unilateral S, Inoue K. Cheiro-oral syndrome following midbrain brainstem. The mechanism of impairment of pain and 7 Onohaemorrhage. J Neurol 1985;232:304-6. temperature sensation in case 1 remains to be 8 Sueda T, Minematsu K, Tagawa K, Yamaguchi T. A case of elucidated. Based on these clinico-radiological findpontine hemorrhage with cheiro-oral syndrome. Neurol Med (Tokyo) 1981;15:286-8. ings, the present cases show at least that a brainstem ShirabeT,TeraoA, Araki S. Unilateral MLF syndrome lesion can produce a sensory defect involving both 9 TawaraS, with palm-oral sensory disturbance-report of a case. Clin sides of the mouth in a cheiro-oral syndrome. Neurol 1974;14:745-51. We thank Drs Asao Hirano, Hidehiro Mizusawa and 10 Brodal A. Neurological Anatomy: in Relation to Clinical Medicine. New York: Oxford University Press, 1981.