CASE REPORT Cavernous Angioma with Olivary Hypertrophy and Contralateral Cerebellar Diaschisis Yuichi Komaba, Tatsuya Nomoto, Shin Kitamura and Akiro Terashi We describe a 66-year-old man with a 20-year history of ataxic gait who suddenly developed diplopia on rightward gaze. Neurologic examination revealed right hemi-ataxia and hemi- hypesthesia, and left internuclear ophthalmoplegia. MRIshowed a cavernous angioma in the left tectum, mild right cerebellar atrophy, and left interior olivary hypertrophy. emission computed tomography (SPECT) imaging demonstrated contralateral chisis. Wediscuss the findings and review the literature cerebellar diascerebellar Key words: single photon emission computed tomography (SPECT), dentato-olivary pathway (Internal Medicine 36: 504-507, 1997) Introduction Crossed cerebellar diaschisis is defined as functional impairment in the cerebellum, which is remote from the causative lesion; it is often demonstrated in patients with contralateral lesions on single photon emission computed tomography (SPECT) or positron emission tomography (PET) imaging ( 1 ). Involvement of the cerebropontine-cerebellar tract is thought to result in crossed cerebellar diaschisis; however, infratentorial lesions interrupting the cerebropontine-cerebellar tract mayalso result in contralateral cerebellar diaschisis in some patients (2-4) [It may be more precise to refer to cerebellar diaschisis with contralateral supratentorial lesion as "crossed cerebellar diaschisis", and cerebellar diaschisis with contralateral photon concerning contralateral diaschisis. supratentorial Single infratentorial lesion as "contralateral cerebellar dias- chisis"]. Here, we describe a patient with a tegmental lesion whoappears to have developed contralateral cerebellar diaschisis as a result of interruption His blood pressure was 160/88 mmHg, andhis pulse rate was 90/min and regular. Physical examination revealed no abnormal findings in his chest and abdomen. On neurologic examination, no pathologic reflexes were elicited. Muscle tone, deep tendon reflexes, and muscle strength were normal in all extremities. There was right hemi-ataxia and right hemihypesthesia to vibration and touch. Movementof the right upper extremity was accompanied by an intention tremor, and his gait was ataxic with rightward deviation. No palatal myoclonus was present. Although left internuclear ophthalmoplegia was found, the ocular position was normal. Tests of cranial nerves revealed impaired hearing on the right due to tympanitis. Except for zinc sulfate turbidity test (ZTT), y-glutamyl transpeptidase (y-GTP), and blood urea nitrogen (BUN), the laboratory findings including blood count, urinalysis mission and blood biochemical profile were normal on ad- (ZTT=12.1 U, y-GTP=47 IU//, BUN=22.3 mg/dl). of the dentato-olivary pathway. Magnetic resonance imaging (MRI) was performed 3 weeks after the onset using a 1.0 T (Impulse Extra, Siemens Co.) system. On T2-weighted MRimages, there was a heterogeneCase Report ous high signal intensity lesion surrounded by a low intensity A 66-year-old man with a 20-year history of ataxic gait, rim in the left tectum (Fig. 1A, B). There was also hypertrophy presented with sudden onset of diplopia on rightward gaze. He of the left inferior olive (Fig. 1C) and mild right cerebellar was admitted to the Nippon Medical School Hospital 2 days atrophy (Fig. ID). On T2-weighted MRimages, the left inferior after onset of symptoms. No history of specific disease except olivary nucleus showed high signal intensity (Fig. IE). Refor right tympanitis at the age of62. His father died from stroke gional cerebral blood flow (rCBF) was measured utilizing the at the age of56, his mother died from cancer at the age of 86, and his siblings are healthy. method described by Iida et al (5). For data acquisition, a SPECTscan was performed after intravenous injection of N- From the Second Department of Internal Medicine, Nippon Medical School, Tokyo Received for publication November 5, 1996; Accepted for publication April 3, 1997 Reprint requests should be addressed to Dr. Yuichi Komaba, the Second Department of Internal Medicine, Nippon Medical School, 3-3-5 Iidabashi, Chiyodaku,Tokyo102 504 Internal Medicine Vol. 36, No. 7 (July 1997) Cavernous Angiomawith Olivary Hypertrophy and Diaschisis Figure 1. A 66-year-old man with right hemi-ataxia and hemi-hypesthesia, and left internuclear ophthalmoplegia. (A) MR image at the level of the upper pons (T2-weighted, axial, TR: 3,800 ms, TE: 120 ms) shows a heterogeneous high signal intensity lesion in the left tegmentum surrounded by a low intensity rim. (B) Sagittal MR image (T2-weighted, TR: 3,800 ms, TE: 120 ms) shows the lesion located in the left side of the tegmentum, and there was no evidence of invasion into the pontine nucleus. (C) Coronal MR image (T2-weighted, TR: 3,900 ms, TE: 120 ms) shows obvious hypertrophy of the left inferior olive. (D) Coronal MRimage (T2weighted, TR: 3,900 ms, TE: 120 ms) shows mild right cerebellar atrophy. (E) MRimage at the level of the medulla oblongata (T2weighted, axial, TR: 3,800 ms, TE: 120 ms) shows hypertrophy of the left inferior olive as a high signal intensity area. Internal Medicine Vol. 36, No. 7 (July 1997) 505 Komabaet al synaptic degeneration of the dentato-olivary pathway (8). The dentato-olivary pathway extends from the dentate nucleus to the contralateral inferior olive, coursing in the superior cerebellar peduncle, crossing the midline at its decussation (the commissure of Wernekink), passing by the internal and dorsal surface of the red nucleus, and becomingpart of the central tegmental tract of the contralateral can be seen with lesions side. Olivary hypertrophy of the dentate nucleus or central tegmental tract and is characterized by enlargement of neurons with vacuolation and bizarre shapes, and enlargement of astrocytes with bizarre nuclei and prominent thick processes (7). Astrocytes are increased in numberand multinucleated, and often there is severe fibrillary gliosis (8-10). The high signal intensity in the hypertrophic olivary nuclei on T2-weighted and proton density-weighted images appears to be due to gliosis and increased intracellular water content (1 1-14). In the present patient, the coronal MRimages demonstrated obvious hypertrophy of the inferior olivary nucleus opposite to the side of the Figure 2. IMPautoradiographic SPECTstudy demonstrates lesion of the central tegmental tract, and axial T2-weighted a reduction of CBFin the right cerebellum (R/L of cerebellum = images demonstrated the hypertrophic olive as an area of high 0.81) (rCBF image). signal intensity. Gautier and Blackwood described patients with lesions in the central tegmental tract who had ipsilateral olivary hypertrophy and pallor of myelin staining surrounding isopropyl-p-[I23I]iodoamphetamine (123I-IMP). The SPECT the contralateral dentate nucleus (15). Kim et al (10) showed scanner was a Headtome-SET080 (Simadzu Co.). We injected that in patients with lesions of the central tegmental tract the 222 MBqof 123I-IMP intravenously as a tracer and measured relative hypointensity of the contralateral dentate nucleus on rCBF (pitch 10 mm, 31 slices, parallel with OMline). We T2-weighted images was due to damage of axonal transport that measured the radioactivity of arterial blood sampled from the caused reduction of iron accumulation in the dentate nucleus. left brachial artery 10 minutes after the start of injection, using Interruption of the cerebropontine-cerebellar tract is thought a scintillator. Westarted to acquire images 25 minutes after the to be the most likely mechanismfor crossed cerebellar diasstart of injection and continued to acquire images for 30 chisis. SPECT or PET imaging often demonstrates crossed minutes. CBF images were created with the SPECT cerebellar diaschisis in patients with contralateral cerebrocortical autoradiographic method (5). A circular region of interest lesions. The cerebropontine-cerebellar tract derives from ex(ROI) of 22 mmdiameter was placed on each cerebellar tensive areas of the cerebrum, passes through the medial and lateral aspect of the cerebral peduncle, and projects to the hemisphere in the CBFimages and each rCBF was calculated. The rCBF of the right cerebellar hemisphere was 37.9 ml/100 ipsilateral pontine nuclei located ventral to the medial lemnisg/min and that of the left hemisphere was 47.2 ml/100 g/min cus (6). Pontine nuclei send axons to the contralateral cerebel(left to right ratio, 0.81). SPECT images (Fig. 2) also showed a lum via the middle cerebral peduncle, traversing the anterior reduction of CBFin the right cerebellar hemisphere confirming pons as the transverse pontine fibers. This explains howeither the contralateral cerebellar diaschisis. a supratentorial lesion maycause crossed cerebellar diaschisis or an infratentorial lesion maycause contralateral cerebellar Discussion diaschisis. In patients with a unilateral pontine lesion, contralateral MRimages of this patient revealed the left tegmental lesion that showed heterogeneous high signal intensity on T2-weighted images, surrounded by a low signal intensity rim. The lesion had the typical appearance of a cavernous angioma. The patient's 20-year history cerebellar diaschisis and ipsilateral supratentorial hypoperfusion have been observed (3, 6). The lesions of the cerebropontine-cerebellar tract within the pons are thought to produce contralateral cerebellar diaschisis. In addition, lesions in the thalamus also cause crossed cerebellar diaschisis, and this of ataxia supports the view that this has been attributed to disruption of the dentato-rubro-thalamic lesion was longstanding; however, the sudden onset ofinternu- pathway (2). In the present patient, MRIdemonstrated that the clear ophthalmoplegia suggests recent bleeding or ischemia. lesion was located in the left central tegmental tract and invaded However, because either Tj-weighted or T2-weighted images the left medial lemniscus. Since the lesion did not involve the of a patient with the subacute stage of cerebral hemorrhage pontine nucleus, this patient's CCDcould not be due to interruption of the cerebropontine-cerebellar tract. Though there show a homogenous high signal intensity which is a reflection of a pooling of dilute-free methemoglobin, the lesion with a maybe no fibers of the dentate-olivary pathway which precisely correspond to fibers of the dentato-rubro-thalamic pathway, the heterogenous high signal intensity may not suggest bleeding. Hypertrophic olivary degeneration is considered to be trans- course from the dentate nucleus to the red nucleus is common. 506 Internal Medicine Vol. 36, No. 7 (July 1997) Cavernous Angiomawith Olivary Hypertrophy and Diaschisis Therefore, we postulate that our patient' s contralateral cerebellar diaschisis may have resulted from interruption of the dentatoolivary pathway, similar to interruption of the dentato-rubrothalamic pathway. References Brodal A. Cerebrocerebellar pathways: Anatomical data and some functional implications. Acta Neurol Scan Suppl 51: 153, 1972. Sohn D, Levine S. The hypertrophy of the olive. A report of43 cases, in: Zimmermann HM(ed) Progress in Neuropathology, vol 3. Grune and Stratton, NewYork, 202, 1971. Lapresle J, Hamida MB. The dentato-olivary pathway: Somatotopic relationship betweenthe dentate nucleus and the contralateral inferior 1) Baron JC, Bousser MG, Comar D, Duquesnoy N, Sastre J, Castaigne P. Kitajima M, Korogi Y, Shimomura O, et al. 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