Dynamics of dot-like hemosiderin spots on T2*-weighted MRIs associated with stroke recurrence.

BACKGROUND AND PURPOSE: Dot-like low-intensity spots (dot-like hemosiderin spots: dotHSs) on gradient echo T2*-weighted (-w) brain magnetic resonance imaging (MRIs) are frequently associated with cerebral small vessel disease (SVD), including deep intracerebral hemorrhages and lacunar infarctions. This study investigated how numbers of newly appeared dotHSs contribute to recurrent SVD. METHODS: We prospectively analyzed numbers of newly appeared dotHSs in 12 patients with prior SVD (8 males, 4 females; mean 67.6 +/- 10.7 years old) readmitted with recurring SVD between October 2001 and March 2003. Numbers of appeared dotHSs per year were counted on T2*-w MRI scans after SVD recurrence and compared to previous MRIs. Seventy-one outpatients (35 males, 36 females; mean 64.3 +/- 9.6 years old) with histories of intracerebral hemorrhages (ICH) that came to the hospital during the study period served as controls. The hazard ratio (HR) for recurrence was estimated from a multivariate logistic regression model, using the number of appeared dotHSs (per year) and other risk factors. RESULTS: Multivariate analyses revealed that an elevated rate of recurrence was found in patients with substantial numbers of appeared dotHSs (>or=5/year) (HR, 7.34; P= 0.0008). We also analyzed factors associated with the numbers of appeared dotHSs. A number of appeared dotHSs (>or=5/year) was significantly and independently associated with the initial number of dotHSs (>or=10) on T2*-w MRIs following the first SVD (HR, 18.6; P= 0.0001). CONCLUSIONS: Though a small sample size limited the power of our analyses, our findings suggest that a number of newly appeared dotHSs may be associated with SVD recurrence.

[Artery-to-artery embolism due to ruptured calcified carotid plaque].

Calcified carotid plaques are thought to be less likely to be symptomatic than non-calcified plaques. We present a patient with an unusual cerebral embolism that appeared as very high density on CT and was ascertained to derive from a calcified plaque. This 46-year-old male was admitted within 1 hr of sudden aphasia onset. The admission CT scan showed multiple high-intensity lesions that appeared like calcification. They were high intensity on MRI FLAIR images. MRA showed occlusion of the posterior trunk of the middle cerebral artery. As we considered cerebral embolism, the patient received heparin followed by warfarin. Routine MRA and DSA detected no abnormality, however, a carotid echogram showed a hyperechoic plaque at the left carotid bifurcation. As the NASCET method indicated 6.5% stenosis, carotid endarterectomy was not indicated. However, the thrombus at the bifurcation gradually enlarged despite adequate medical treatment (PT-INR 2.2 - 2.7) and we decided to surgically remove the calcified plaque, thought to be the embolus source. We removed the plaque content through a defect in the plaque membrane. Intraoperatively we found that the rapidly enlarging lesion was the plaque content rather than a thrombus. Pathologically, calcification was more dominant than atherosclerosis. His postoperative course was good and he required only aspirin. This case was peculiar in that the calcification mimicked a hyperdensity embolus and that the lesion derived from a calcified plaque which is usually stable. Repeat carotid ultrasonography is easy and useful when routine investigation fails to reveal the embolic source.

Dot-like hemosiderin deposition on T2*-weighted MR imaging associated with nonhypertensive intracerebral hemorrhage.

BACKGROUND AND PURPOSE: Microangiopathy, a disorder often related to hypertension, is an important cause of deep intracerebral hematoma (ICH). The microangiopathy is associated with dot-like low-intensity spots (a dot-like hemosiderin spot: dotHS) on gradient-echo T2*-weighted MR images that have been histologically diagnosed as old microbleeds. The locations of dotHS are consistent with deep ICH. METHODS: To investigate how dotHS or other risk factors contribute to nonhypertensive deep ICH, the number and location of dotHSs, as well as other risk factors were examined in 213 deep ICH patients (106 males, 107 females, age: 37-94 (65.8 +/- 11.2) years) consecutively admitted to Hakodate Municipal Hospital. Patients were divided into two subgroups according to the presence or absence of hypertension. DotHSs were also divided into deep and subcortical dotHS and investigated independently. Odds ratios (ORs) were estimated from logistic regression analyses. Furthermore, nonhypertensive ICH patients were compared with nonhypertensive healthy volunteers matched for age and sex. RESULTS: No risk factors were identified in the 31 nonhypertensive deep ICH patients that differed from those found in the 182 hypertensive deep ICH patients. Deep dotHS > or = 1 (OR: 25.5; 95% CI: 4.76-137; P = .0002), subcortical dotHS > or = 1 (OR: 9.0; 95% CI: 1.79-44.9; P = .046), diabetes mellitus (OR: 9.0; 95% CI: 1.53-52.3; P = .015), and smoking (OR, 9.6; 95% CI; 1.8-49.8, P = .007) significantly elevated the risk of nonhypertensive ICH, compared to the healthy volunteers. CONCLUSIONS: Our findings suggest that deep and subcortical dotHSs may be risk factors for the development of non-hypertensive deep ICH.

Detection of hemosiderin deposition by T2*-weighted MRI after subarachnoid hemorrhage.

BACKGROUND AND PURPOSE: Subarachnoid hemorrhage (SAH) is very difficult to diagnose several months after its onset. We thus investigated subarachnoid hemosiderin deposition well after SAH by T2*-weighted MRI, a sensitive method for hemosiderin detection. METHODS: To investigate how hemosiderin deposition as confirmed by T2*-weighted MRI contributes to the determination of prior SAH and how the extent of hemosiderin deposition is associated with a number of clinical factors, we retrospectively analyzed 58 patients >3 months after SAH associated with ruptured aneurysms. We also investigated 209 healthy volunteers as controls. RESULTS: T2*-weighted MRI demonstrated subarachnoid hemosiderin deposition in 72.4% of the SAH patients, whereas no deposition was seen in the healthy volunteer group. The hemosiderin was preferentially deposited in the subarachnoid space near a ruptured aneurysm. Odds ratios (ORs) were estimated from logistic regression analyses correlating hemosiderin deposition with other factors. Age (>or=54 years) (OR, 5.1; 95% CI, 1.03 to 25.0; P=0.046), Fisher grade 3 on initial CT (OR, 8.0; 95% CI, 1.26 to 50.4; P=0.027), and Karnofsky Scale score

Highly oriented aragonite nanocrystal-biopolymer composites in an aragonite brick of the nacreous layer of Pinctada fucata.

13C CP/MAS NMR and FE/TEM measurements of the aragonite brick of the nacreous layer of Pinctada fucata indicate that it assembles with highly oriented aragonite nanocrystals, which are regulated by biopolymers.

Dynamics of dotlike hemosiderin spots associated with intracerebral hemorrhage.

The authors observed dotlike, low-intensity spots in T2*-weighted magnetic resonance imaging (MRI), subsequently diagnosed histologically as previous microbleeds associated with lipofibrohyalinosis, amyloid angiopathy, and small vessel disease. The nature of dotlike hemosiderin spots (dotHSs), however, is still unknown. This case report seeks to demonstrate the dynamics of dotHSs associated with an intracerebral hematoma (ICH). T2*-weighted MRI of a 72-year-old man with a history of hypertension demonstrated 4 dotHSs 24 months after a left putaminal hemorrhage. Follow-up T2*-weighted MRI 40 months after the acute event demonstrated the asymptomatic formation of 3 more dotHSs, even with good control of blood pressure. Fifty months after the stroke, T2*-weighted MRI showed that 2 of the new dotHSs had become fainter, whereas the hemosiderin associated with the ICH scar remained detectable. To the authors' knowledge, this is the first description of dotHS dynamics associated with ICH.

Dot-like hemosiderin spots on gradient echo T2*-weighted magnetic resonance imaging are associated with past history of small vessel disease in patients with intracerebral hemorrhage.

BACKGROUND AND PURPOSE: Lipohyalinosis is considered an important cause of cerebral small vessel disease (SVD), including hypertensive intracerebral hematoma (ICH) and lacunar infarction. Dot-like low-intensity spots (dot-like hemosiderin spots [dotHSs]) on gradient-echo T2*-weighted (T2*-w) magnetic resonance imaging (MRI) have been histologically diagnosed as old microbleeds associated with microangiopathies (lipohyalinosis, amyloid angiopathy) and located in territories of perforating arteries (deep dotHSs) and subcortical regions (subcortical dotHSs). If dotHSs indicate the severity of lipohyalinosis, larger numbers of deep dotHSs may be associated with past history of SVD. METHODS: The number of dotHSs was investigated in 213 patients with deep ICH (106 men, 107 women, 37 to 94 years old, mean age = 65.8 +/- 11.2 years). Patients were divided into 2 subgroups according to past history of SVD. Odds ratio (OR) for the history was estimated from logistic regression analyses of the number of deep or subcortical dotHSs, as well as other factors. RESULTS: Of 213 patients, 36 had a past history of SVD (symptomatic deep ICH in 18, symptomatic lacunar infarction in 17, and both in 1). An increased rate of history of SVD was found for patients with subcortical dotHSs. The OR per 1 subcortical dotHS was 1.09 (95% confidence internal (CI), 1.03-1.17; P =.005), and per deep dotHS, the OR was 1.07 (95% CI, 1.00-1.13; P =.039). CONCLUSIONS: The findings suggest that deep and subcortical dotHSs on T2*-w MRI may indicate the severity of microangiopathy and may predict recurrence of SVD in patients with deep ICH.

[A case of a ruptured pseudoaneurysm arising from the distal part of the posterior inferior cerebellar artery].

We report a rare case of a pseudoaneurysm arising from the distal part of the posterior inferior cerebellar artery (PICA) and which was associated with intraventricular hemorrhages. A 48-year-old female had sudden onset of severe headache and vomiting, and was admitted in a semicomatous state to our hospital. Initial CT scan showed ventricular hematomas resulting in acute hydrocephalus, but no obvious parenchymal or subarachnoid hemorrhage. Ventricular drainage was carried out. Subsequently, cerebral angiography was performed, but neither, an aneurysm nor other vascular abnormality was detected. 50 days after admission, MRI revealed a homogenous and well-circumscribed hypointense mass (12 mm in diameter) in the right cerebellar tonsil, suggesting the presence of hemosiderin. 60 days after the onset, the second angiography showed an aneurysmal shadow arising from the distal part of the PICA. An aneurysmal clipping was performed via the suboccipital approach. A thrombosed aneurysm was identified in the right tonsil. At the time of the operation, we confirmed that the part of the PICA around the aneurysm was intact with neither branching nor discoloration. Histological examination revealed that elastic fiber was not identified in the aneurysmal wall, and the aneurysm was diagnosed as a pseudoaneurysm. Histories of trauma or infection, which may have induced the cerebral pseudoaneurysm, were not obtained by interview.

[Solitary brain metastasis from medullary carcinoma of the thyroid].

A 55-year-old woman first underwent total thyroidectomy in 1973, and the histopathology was medullary thyroid carcinoma. There was no familial history of endocrine neoplasm. She remained asymptomatic for the next 19 years. Neck and tracheal recurrence was treated with tracheal stent and radiation, in 1997. On July 1998, she presented with headache. Magnetic resonance imaging revealed a gadolinium enhanced mass in the left inferior temporal gyrus. Angiogram revealed a marked tumor stain feeding from the middle and inferior temporal artery. The tumor was successfully excised via a temporal craniotomy. Histopathological sections of the resected specimen confirmed the diagnosis, it demonstrated the medullary pattern that was composed of vascular stroma and clumps of cells. Immunocytochemistry, using carcino-embryonic antigen and calcitonin showed a strongly positive reaction, and MIB-1 was 5.4%. The patient subsequently underwent a course of whole brain radiotherapy, a total of 30 Gy/10 fr. She remains asymptomatic 14 months after treatment. Brain metastasis from medullary carcinoma of the thyroid is extremely rare and it does not usually occur distant spread. Thyroid carcinoma with brain metastasis tends to be identified in patients with older age, larger primary tumor, more frequent evidence of extrathyroidal invasion, and more aggressive histologies. The number of medullary thyroid carcinoma with brain metastasis is small and there has been little evidence from benefit of therapy. Neither is it clear wether radiation therapy is beneficial also is not clear. In this case, surgical resection and radiation therapy was effective against recurrence of other lesion.

[Preemptive analgesia for postoperative pain after frontotemporal craniotomy].

Two thirds of patients suffer from moderate to severe pain after frontotemporal craniotomy. We think neurosurgeons must try to reduce the postoperative pain, which may induce postoperative hypertension, restlessness, and pathological pains. To investigate how preemptive analgesia effects postoperative pain, we assessed the pain in 20 consecutive patients who underwent neck clipping for non-ruptured cerebral aneurysms of anterior circulation systems by frontotemporal craniotomies. Ten patients underwent preemptive analgesia with four procedures (preemptive group) as follows, 1) oral administration of long-acting non-steroid anti inflammatory drug (NSAID, ampiroxicam) two hours before the surgical operation, 2) nerve blockades of the supra-orbital nerve and the infra-orbital nerve by bupivacaine, 3) local anesthesia of the scalp along the marker of a skin incision by xylocaine, 4) local anesthesia by bupivacaine along a skin incision after the skin closure. Ten patients of the control group underwent only procedure No. 3. Visual analog pain score (VAS) for postoperative pain 6, 12, and 24 hours, and 3, 5, 7, and 14 days after operation and NSAID administration for the pain were evaluated. Patients of the preemptive group had significantly less postoperative pain during the whole post-surgery period and required less administration of NSAID than the control group. Preemptive analgesia procedures No. 1, 2 and 4 reduced the postoperative pain and the total administration of NSAID. Postoperative pain may be reduced after other types of brain surgery, with proper nerve blocks like procedure No. 2, procedures No. 1, 3 and 4.

[A case of deep cerebral venous thrombosis with sudden convulsion after delivery].

A 25-year-old woman was admitted to our hospital because of convulsions after delivering a baby. Her neurological examination revealed a disturbance of consciousness and weakness in both arms. A brain magnetic resonance imaging scan (MRI) showed thrombosis of the left transverse sinus and many patchy high signals at bilateral basal ganglia and subcortical areas. A digital subtraction angiogram (DSA) of the brain revealed a defect at the left transverse sinus, congestion of the cerebral venous flow at the vein of Galen and vasospastic changes at both posterior cerebral arteries. After treating the patient with a venous infusion of heparin, nicardipine and phenytoin, her neurological deficits improved within a day. When MRI and DSA were repeated 2 weeks later, the abnormal lesions had disappeared. These findings suggest that venous thrombosis and vasospasm had the pathogenesis of eclampsia in this case.

[Dynamic changes in magnetic resonance diffusion-weighted and fluid-attenuated images of cerebral fat embolism: a case report].

Cerebral fat embolism (CFE) is serious complication of a long-bone fracture. We reported magnetic resonance (MR) diffusion-weighted (DWI) and fluid attenuated inversion recovery (FLAIR) images in a patient suffered with CFE. A 26-year-old man with a right femoral bone fracture lapsed into a semicoma eight hours later. Eighteen hours after the depressed consciousness, DWI and FLAIR images on MR imaging showed multiple high-intensity spots in corona radiata, basal ganglia, thalamus, corpus callosum, brain stem and cerebellum. Thereby, he was diagnosed as CFE. These multiple lesions were more detectable on FLAIR images than DWI, particularly in posterior fossa. Eight days after the onset, follow-up DWI, FLAIR, and T 2-weighted MR image (T 2 WI) showed most of the lesions disappeared or shrunk. The resolution of the lesions suggests that most of the lesions were brain edema as a result of the unique pathophysiological condition of CFE. The remained lesions were diagnosed as cerebral infarctions. The consciousness of the patient improved alert. Three months later, follow-up MRI showed almost complete resolution of the abnormal intensities. Follow up DWI and FLAIR images observed in the patient indicated that many small lesions occurs throughout the whole brain without a preferential region, and many of the lesions can subside or attenuate in CFE.

Syringo-subarachnoidal shunting to correct unilateral leg deformity in a child with terminal syringomyelia: case report.

INTRODUCTION: Among cases with terminal syringomyelia, 25% are associated with tethered cord syndrome. As it can be difficult to determine whether the neurological deficits are attributable to a syrinx or to a coexisting occult spinal dysraphism, it is not easy to determine the correct surgical strategy. CASE: We report a 19-month-old girl with an underdeveloped right leg and pes varus detected when she was 1 month old; lumbosacral magnetic resonance imaging (MRI) revealed syringomyelia. She developed recurrent urinary tract infections and consulted our department with a diagnosis of congenital neurogenic bladder. She presented with clubbed equine position, wore a short brace on her underdeveloped right leg, and exhibited limping gait due to shortening of the right leg. There was no anal reflex. The skin on her lower back was normal. MRI study showed that the lower end of the conus medullaris existed at the L3/4 level; central-type syringomyelia was recognized in the conus medullaris at the T12/L1-L2/L3 level. Computed tomography myelography detected no trabeculae causing tethering effects or influx of contrast medium into the syrinx. There was no comorbid disease like hydrocephalus or Chiari malformation. We performed syringo-subarachnoidal shunt by L1-L2 hemilaminectomy. RESULT: Postoperative MRI confirmed shrinkage of the syrinx. One year later, although her perianal sensory loss and bowel and bladder dysfunction remained, her right leg had caught up with the left and at 1 year and 9 months after the procedure there is no discrepancy in her legs and she is able to run without limping.