Tohoku J. Exp. Med., 2001, 195, 135-140 Case Report Two Cases of Japanese CADASIL with Corpus Callosum Lesion Kaori Iwatsuk1, Tetsuro Murakami, Yasuntro ManaBe, Hisasut Narat, Hrrosu1 Warira, Takesa1 Hayasnt and Kosi ABE Department of Neurology, Graduate School of Medicine and Dentistry, Okayama University, Okayama 700-8558 Iwarsvk1, K., Muraxamt, T., Manasz, Y., Narat, H., Warrra, H., Havaset, T. and Asn, K. A CADASIL Family of Japan with Corpus Callosum Lesion. Tohoku J. Exp. Med., 2001, 195(2), 185-140 —— Cerebral autosomal dominant arteriopathy with subcortical infarcts and leucoencephalopathy (CADASIL) is a rare hereditary stroke disease. In the present study, a Japanese CADASIL family was first reported with missense mutation of Argl41Cys of Notch3 and a unique lesion of corpus callosum. Upon neuropsychological examination, our case 1 showed only right-handed constructional apraxia associated with corpus callosum lesion. Sagittal T2 weighted image of case 1 showed multiple small lesions along with the pericallosal branches from the truncus to the posterior part of the splenium in the corpus callosum. Although detailed mapping of the corpus callosum for functional fractionation in humans remains incomplete, the constructional apraxia on the right may be related to callosal dysfunction from the truncus to the posterior part of the No other callosal disconnection signs were present. splenium in the corpus structional apraxia © 2001 Tohoku University Medical Press Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoence- phalopathy (CADASIL) is an inherited cere- brovascular disease characterized by recurrent subcortical ischemic strokes starting in midadulthood, with stepwise progression over two decades, often leading to pseudobulbar palsy, dementia, mood disturbances, and recur- rent attacks of severe migraine (Sourander and Walinder 1977; Tournier-Lasserve et al. 1991; callosum, ————— CADASIL; corpus callosum; con- Hutchinson et al. 1995). However, vascular risk factors including hypertension, diabetes mellitus, hyperlipidemia are usually absent. Brain magnetic resonance imaging (MRI) shows multiple subcortical infarcts and widespread white matter lesions. Recent genetic studies have identified missense mutaitons of the Notch3 gene on chromosome 19 in CADASIL patients (Joutel et al. 1996, 1997). In the initial reports, multiple subcortical Received August 6, 2001; revision accepted for publication October 26, 2001. Address for reprints: Yasuhiro Manabe, M.D., Department of Neurology, Graduate School of Medicine and Dentistry, Okayama University, 2-5-1 Shikata-cho, Okayama 700-8558, Japan. e-mail:manabe @ cc.okayama-u.ac.jp 136 K. Iwatsuki et al. infarcts and widespread white matter lesions in the cerebral hemisphere were pointed out in CADASIL patients (Skehan ect al. 1995). Though a few recent reports pointed the lesion of cerebellum, brainstem, and corpus callosum (Yousry et al. 1999; Coulthard et al. 2000), subtentorial and corpus callosum lesions were considered to be rare. Symptoms of CADASIL could be variable depending on the site of lesion, However, a symptom with lesion of corpus callosum has never been reported. Here we report a Japanese family of CADASIL with corpus callosum lesion associated with a missen- se mutation (Argl41Cys) of the Notch3 gene. CASE REPORT Case 1 A 57-year-old right-handed woman began to have migraine with aura from 33 years old. Walking imbalance and slowing of speech and physical activity began at age 52. Soon after such symptoms, she developed a transient is- chemic attack (TIA) with right hemiplegia and dysarthria. With MRI examination, she was diagnosed as having multiple cerebral infarc- tion in the white matter of cerebrum. There- after similar TIAs repeated several times, and her emotional volition decreased. She was in a depression state at age 56. She did not have hypertension, hyperlipidemia nor diabetes mel- litus. In her family, her grandfather, father, aunt, and two of her siblings had the same disease. On admission at age 57, she showed normal blood pressure (130/88 mmHg) and normal general physical findings including the chest and abdomen. On neurological examination, her con- sciousness was clear, but she showed slow speech and bradykinesia. Smooth pursuit eye move- ment was saccadic. No abnormalities were found in other cranial nerves. She showed cerebellar ataxia such as dysdiadochokinesis and impossible tandem gait. There was neither limbs muscle atrophy nor sensory impairment. Deep tendon reflexes were hyperactive. Hoffmann and Babinski reflexes were present bilaterally. Blood, urine and cerebrospinal fluid (CSF) examinations were all normal. Gene analysis of the three patients was performed. Genomic DNA was isolated from TasLe 1. Clinical characteristics of affected members in this CADASIL family Case 1 2 3 Age 57 54 64 Sex Female Female Male Age at onset 33 41 34 Disease duration 24 13 31 Migraine + ~ ne Dysarthria + + + Dysphagia _ — + Hemiparesis _ + + Spasticity + + + Sensory deficits — + + Gait ataxia + — ne. Depression + + ne. Corpus callosum lesion + + ne. Honstructional impairment rt./It. +/- — /ne. me. Cognitive deficits (Demented) _ + ne. Mini mental state examination 30 13 ne. ne., not evaluated. CADASIL with Corpus Callosum 137 blood leucocytes using a standard procedure after informed consent was obtained. Exons 3 to 5 of the Motch3 gene were amplified by polymerase chain reaction (PCR). The sense and antisense primer were 20-mer, 5’- CTGCCCAACCAAGCCATCTC-3’ and 5’- CTCTCGCCTGTCCAGCCATT-3’, respective- ly. PCR was performed in a 50-y1 reaction mixture containing 1 xg of genomic DNA, 1U of Taq polymerase, and 10 pg of each primer. After an incubation at 95°C for 5 minutes, steps of 95°C for 60 seconds, 57°C for 60 seconds, 72°C for 120 seconds were repeated for 35 cycles, followed by an incubation at 72°C for 5 min- utes. An aliquot of the PCR product was reacted with Dye Terminator Kit (Amersham Pharmacia Biotech, NJ, USA), and the reaction product was analyzed using an automated DNA sequencer (Long Read Tower, Amersham Pharmacia Biotech). Sequence analysis of the proband showed a heterozygous mutation of a normal sequence and a transition of C to T, which resulted in the substitution of Arg to Cys (R141C) in exon 4 of the Notch3 gene. Ultrastructural analysis of skin vessels disclosed ganular osmiophilic material within the vascular smooth muscle basal lamina. In higher cerebral function, her intelligent quotient was 80 (verbal scale, 92; performance scale, 66) on Wechsler adult intelligence scale- revised, but her mini mental state examination (MMSE) scale was 30/30. Test for brick was poor on the right hand but good on the left hand. Upon neuropsychological examination, model right hand the model cube was copied fairly well by the left hand but not by the right hand (Fig. 1). She showed right-handed constructional aprax- ia. However, no other callosal disconnection signs including the left-limb apraxia were pres- ent. Neither aphasia, ideomotor apraxia nor anosognosia were observed. No unilateral spa- tial neglect was found. Brain MRI showed multiple hyperintense lesions with T2-weighted image in the anterior portions of the temporal lobe and cerebellum, and basal ganglia, subcortical cerebral hemi- spheres bilaterally (Figs. 2A and 2B). The multiple lesions of the corpus callosum are along with the pericallosal branches of the anterior cerebral artery from the truncus to the posterior part of the splenium (Fig. 2C, arrow- heads). A little decrease in cerebral blood flow in bilateral frontal and temporal lobes and the right parietal lobe was detected by °™Tc- HMPAO single photon emission computed tomography. Case 2 A 54-year-old right-handed woman is a sister of case 1. She first noticed sensory dis- turbance of temperature in left body at age 41, and was diagnosed as having multiple cerebral infarction in the white matter of cerebrum and rostral part of pons on MRI examination. She did not have hypertension, hyperlipidemia nor diabetes mellitus. had dysarthria and dysphasia as symptoms of a TIA. She then had a permanent left hemi- Thereafter, she sometimes left hand Fig. 1. Showing right-handed constructional apraxia of case 1. The model cube was copied fairly well by the left hand but not by the right hand. 138 K. Iwatsuki et al. Fig. 2. A: Axial T2 weighted image of case 1 at the level of the thalami shows confluent, bilateral and symmetrical subcortical hyperintensities. B: Axial T2 weighted image of the same patient at the level of the centrum semiovale shows hyperintensity multiple small lesions, confluent, bilateral and symmetrical subcortical hyperintensities. C: Sagittal T2 weighted image of case 1 shows multiple small lesions along with the pericallosal branches of the anterior cerebral artery from the truncus to the anterior part of the splenium (arrowheads). found in case 2 (D, arrowheads). plegia and became depressed at age 43 and demented at age 50. On medical examination at age 54, she showed normal findings of the chest and abdo- men with normal blood pressure (120/74 mmHg). Neurologically, her speech was dysar- thric, and smooth pursuit eye movement was saccadic. No abnormalities were found in other cranial nerves, and muscle volume or power in the extremities. Sensory disturbance was unidentified due to dementia. Deep ten- don reflexes were hyperactive. Snout and She did not Blood, urine and Case 2 had the same missense mutation as casel in the Notch3 gene. The skin biopsy was not perfor- Babinski reflexes were present. show cerebellar dysfunction. CSF examinations were all normal. The similar lesion is also med. In higher cerebral function, she had dementia with MMSE scale of 13/30. She did not obviously show right-handed constructional apraxia. The left-handed constructional apraxia and callosal disconnection signs containing the left-limb apraxia was not evaluated due to her left hemiplegia. Neuro- psychological examination including aphasia, ideomotor apraxia, anosognogia, and unilateral spatial neglect was not also evaluated due to dementia. Brain MRI showed multiple hyperintense lesions with T2-weighted image in the bilateral brainstem, basal ganglia, and subcortical cere- bral hemispheres predominantly in right side. The lesion of the corpus callosum (Fig. 2D, arrowheads) was similar to case 1 (Fig. 2C). CADASIL with Corpus Callosum 139 Such lesion was smaller than case 1. Case 3 A 64-year-old right-handed man is an elder brother of case 1. He had frequent dysarthria as TIA from age 34. He developed left hemi- plegia at age 37, then right hemiplegia at age 41. These cerebrovascular events resulted in akinetic mutism at age 50. He is bed-ridden now. Brain MRI was not performed. He did not have hypertension, hyperlipidemia nor diabetes mellitus. He also has a missense mutation of Argl41lCys in the Notch3 gene. Neuropsychological examination and the skin biopsy were not performed. Clinical character- istics of cases 1-3 are summarized in the Table 1. DISCUSSION In the present study, a Japanese CADASIL family was reported with missense mutation of Arg]141Cys and a unique lesion of corpus cal- losum. The missense mutation is located within the extracellular domain coded in exon 4, which forms epidermal growth factor-like repeats of the Notch3 protein. This missense mutation of Argl41Cys was reported in 6 patients with CADASIL in France (Joutel et al. 1997), but is the first from Japan (Kotorii et al. 2001). The main lesion in CADASIL has been recognised in the white matter of immediate periventricular or subcortical regions, the basal ganglia, thalamus, and external capsule. Recent reports pointed out that lesions are also present in brainstem, cerebellum, and corpus callosum (Yousry et al. 1999; Coulthard et al. 2000). Neuropathologically the lesion in cor- pus callosum was demyelinated, and that was radiologically hypointense on Tl-weighted and hyperintense on T2-weighted images, and multi- ple thick lesions with the atrophic corpus cal- losum on sagittal T2 weighted images (Gazzaniga et al. 1965; Coulthard et al. 2000). Our cases also showed similar MRI findings (Fig. 2). However, signs associated with lesion of corpus callosum have never been reported in CADASIL. Upon neuropsychological exami- nation, our case 1 showed only right-handed constructional apraxia associated with corpus callosum lesion. No other callosal disconnec- tion signs were present. Sagittal T2 weighted image of case 1 showed multiple small lesions along with the pericallosal branches from the truncus to the anterior part of the splenium (Fig. 20, arrowheads). Previous studies have indicated that constructional apraxia on the right was present in patients with complete commissurotomy (Gazzaniga et al. 1965, Bogen 1969; Zaidel and Sperry 1977). Although detailed mapping of the corpus callosum for functional fractionation in humans remains incomplete (Graff-Radford et al. 1987; Suzuki et al. 1998), the constructional apraxia on the right may be related to callosal dysfunction from the truncus to the posterior part of the splenium. 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