Kotaro Miyashita

Tortuosity of the white matter medullary arterioles is related to the severity of hypertension.

Background: The clinical implication of the tortuosity of white matter medullary arterioles has never been clarified precisely. We quantitatively investigated the relationship between such vascular tortuosity and the severity of hypertension (HT), which was graded according to the WHO classification. Methods: Forty-seven autopsied brains with age-adjusted stages of HT were evaluated. The largest tortuosity diameter and the largest vascular diameter in the same tortuous lesion were measured by light microscopic observation at the level of the corona radiata and centrum semiovale. A maximum ratio of these diameters was calculated for each patient. Results: Maximum ratios were found in almost all arterioles and were significantly increased according to the HT stages. Conclusions: Arteriolar tortuosity in the hemispheric white matter may reflect the severity of HT and be an indicator of hypertensive small vessel disease of the brain.

Genetic Variations of CYP2C9 in 724 Japanese Individuals and Their Impact on the Antihypertensive Effects of Losartan

CYP2C9, a drug-metabolizing enzyme, converts the angiotensin II receptor blocker losartan to its active form, which is responsible for its antihypertensive effect. We resequenced CYP2C9 in 724 Japanese individuals, including 39 hypertensive patients under treatment with losartan. Of two novel missense mutations dentified, the Arg132Gln variant showed a fivefold lower intrinsic clearance toward diclofenac when expressed in a baculovirus-insect cell system, while the Arg335Gln variant had no substantial effect. Several known missense variations were also found, and approximately 7% of the Japanese individuals (53 out of 724) carried one of the deleterious alleles (CYP2C9*3, *13, *14, *30, and Arg132Gln) as heterozygotes. After 3 months of losartan treatment, systolic blood pressure was not lowered in two patients with CYP2C9*1/*30, suggesting that they exhibited impaired in vivo CYP2C9 activity. CYP2C9*30 might be associated with a diminished response to the antihypertensive effects of losartan.

Linear Hyperintensity Objects on Magnetic Resonance Imaging Related to Hypertension

Linear hyperintensity lesions, which are sometimes recognized in the cerebral white matter on T2-weighted magnetic resonance (MR) images, have never been studied from the clinical viewpoint. We refer to these lesions as linear hyperintensity objects (LHOs) and have investigated them quantitatively. Twenty-six consecutive patients underwent routine 1.5-Tesla MR imaging. LHOs were found in 24 patients. We measured the width and number of LHOs at the upper corona radiata level on T2-weighted images (repetition time: 4,500.0 ms, echo time: 96.0 ms) using a scale loupe. The diameters were significantly correlated with the stages of hypertension (WHO classification). The LHOs may associated with the dilated perivascular spaces of cortical medullary arteries and may become an indicator for hypertensive small vessel disease.

How Commonly Is Stroke Found in Patients with Isolated Vertigo or Dizziness Attack

BACKGROUND The sudden development of vertigo or dizziness without focal neurological symptoms is generally attributable to vestibular diseases such as benign paroxysmal positional vertigo. Isolated vertigo or dizziness attack needs more attention than vestibular diseases. This retrospective study was performed to elucidate the frequency of strokes in patients with isolated vertigo or dizziness attack. SUBJECTS AND METHODS We enrolled 221 patients (men, 119; women, 102; mean age, 68.4 ± 10.3 years) who were admitted to our hospital over the last 10 years because of sudden isolated vertigo or dizziness attack without other neurological symptoms except for nystagmus, deafness, or tinnitus. We investigated the clinical features, final diagnosis, neuroimaging findings, and short- or long-term outcome of these patients. RESULTS One hundred eighteen patients had vertigo whereas the other 103 had dizziness. Brain computed tomography or magnetic resonance imaging revealed recent stroke lesions in 25 patients (11.3%) (ischemic, 21; hemorrhagic, 4).The lesions were generally small and localized in the cerebellum (n = 21), pons (n = 1), medulla oblongata (n = 1), or corona radiata (n = 1). Of the 25 patients, 19 (76%) had dizzy-type spells; none had neurological dysfunction at the time of discharge. In the remaining 196 patients, no stroke was detected on computed tomography or magnetic resonance imaging. CONCLUSIONS Stroke was found in 11% of patients with isolated vertigo or dizziness attack. The posterior inferior cerebellar artery area was the most frequently implicated for isolated vertigo or dizziness.

Old Cerebral Hemorrhages in Cases of Multiple Lacunar Infarction Found by Magnetic Resonance Imaging

In magnetic resonance imaging, cerebral infarcts are depicted as hyperintensity areas on T2-weighted images, whereas old intracerebral hemorrhages appear as hypointensity areas with or with

Progressive dysarthria and bilateral sensory disturbance in a case of bilateral ventrolateral pontine infarction

A rare case of bilateral ventrolateral pontine infarction in a 70-year-old man who developed progressive dysarthria and bilateral sensory disturbance is reported with literature review. He had been diagnosed with hypertension, dyslipidemia, and impaired glucose tolerance 10 years earlier. Ten days before admission, he was aware of the difficulty in walking and speaking, which gradually worsened. On admission he showed bilateral thermal hypoalgesia of face and lower extremities, dysarthria, dysphagia, and ataxic gait. High resolution three-dimensional MRI revealed bilateral ventrolateral pontine infarction with a large atherosclerotic plaque in the ventral side of the basilar artery, which led to a diagnosis of atherothrombotic brain infarction. The atherosclerotic plaque in the basilar artery was thought to be responsible for simultaneous occlusion of the bilateral short circumflex arteries of the pons.

Right parietal source in Mahjong‐induced seizure: a system epilepsy of focal origin

Mahjong, a game similar to bridge and chess in Western cultures, can cause reflex seizure. We report a case of Mahjong‐induced seizures with the first documentation of ictal electroencephalography (EEG) findings, which showed secondarily generalized partial seizure of the right parietal origin.