Comparative analysis of the spatial distribution and severity of cerebral microbleeds and old lacunes

BACKGROUND

Cerebral microbleeds, which result from microangiopathic changes following chronic hypertension, may reflect bleeding-prone microangiopathy. However, the distribution of these lesions has not been compared with that of lacunes, which represent occlusive type microangiopathy.

OBJECTIVES

To compare the cerebral distribution of microbleeds and lacunes and correlate their severity.

METHODS

The study population comprised 129 hypertensive patients who underwent brain magnetic resonance imaging (MRI), including gradient echo (GE) sequences. Cerebral microbleeds were counted using GE-MRI data, and lacunes were also counted by comparing T1 and T2 weighted MRI. To investigate the distributions, the number of patients with each type of lesion was compared, and the occurrence index (the total number of the specific lesions divided by the total number of patients) was examined statistically. Correlation analyses were done on the relations between the different grades of microbleeds, lacunes, and leukoaraiosis.

RESULTS

Cerebral microbleeds and lacunes were found at various foci in the brain, with a preference for the cortico-subcortical region and the deep grey matter. The occurrence index of microbleeds, but not of lacunes, was significantly higher in the cortico-subcortical region than in the deep grey matter. The severity of the microbleeds was positively correlated with the severity of lacunes, and both types of lesion were closely correlated with the degree of leukoaraiosis.

CONCLUSIONS

These data suggest that microbleeds and lacunes tend to occur to a similar extent in long standing hypertension, but not necessarily in the same locations.

Cerebral microbleeds are regionally associated with intracerebral hemorrhage

BACKGROUND

Cerebral microbleeds (CMB) may be indicative of a hemorrhage-prone microangiopathy.

OBJECTIVE

To determine if increased numbers of these lesions are predictive of intracerebral hemorrhage (ICH), especially in terms of a distributional association.

METHODS

The authors examined consecutively 227 patients with acute stroke. CMB were counted using T2*-weighted gradient echo MRI data, and old lacunes and leukoaraiosis were also evaluated. The associations between the vascular risk factors and ICH were analyzed. With use of multivariate logistic regression analysis, the locations of the CMB or the old lacunes, which were categorized as being in the corticosubcortical area, the deep gray matter area, or the infratentorial area, were examined with regard to their relationships to the locations of the ICH.

RESULTS

The degrees of the CMB (r = 0.43, p < 0.01) and leukoaraiosis (r = 0.20, p < 0.01) were well correlated with the presence of ICH. Multivariate analysis revealed that the grades of the CMB were associated with the presence of ICH (p < 0.01, odds ratio [OR] = 2.67). CMB in the corticosubcortical area (p < 0.01, OR = 5.50) or deep gray matter (p < 0.01, OR = 2.55) were strongly associated with the presence of ICH in the same area, but no such association was observed in the case of CMB in the infratentorial area or in the case of old lacunes in any area.

CONCLUSIONS

Cerebral microbleeds are strongly associated with the presence of intracerebral hemorrhage, and the distributional associations are also quite strong.

Idiopathic normal pressure hydrocephalus predominantly with prolonged fever and hyponatremia

Described is a patient with hydrocephalus and a gait disorder with associated prolonged fever and hyponatremia. The authors made a diagnosis of normal pressure hydrocephalus (NPH) and performed a ventriculoperitoneal shunt, which improved the gait disturbance, accompanied by resolution of the fever and hyponatremia.

Targeted hsp70.1 disruption increases infarction volume after focal cerebral ischemia in mice

BACKGROUND AND PURPOSE

Heat-shock proteins (HSPs) are highly conserved proteins that are induced by a variety of stresses. HSP70 is a 70-kDa HSP family known to have cytoprotective effects against various insults. The role of HSP70 in cerebral ischemia remains to be elucidated in vivo.

METHODS

To investigate the effect of reduced HSP70 levels on cerebral ischemia, focal cerebral ischemia by intraluminal occlusion of the middle cerebral artery was induced in hsp70.1 knockout mice. The expressions of hsp70.1 and hsp70.3 mRNAs and HSP70 protein were determined, and infarction volumes were measured and compared.

RESULTS

Northern blots confirmed the absence of hsp70.1 mRNA expression in the knockout mice. The mean infarction volume was significantly larger in hsp70.1 knockout mice (92.5+/-8.3 mm(3)) than in the wild-type mice (59.3+/-8.9 mm,(3) P<0.001). Western blots showed increased HSP70 expression in the ischemic hemisphere in both knockout and wild-type mice, but HSP70 expression levels in knockout mice were significantly lower than those in their wild-type littermates. Immunohistochemistry did not show any significant differences between the knockout and wild-type animals and showed increased HSP70 immunoreactivity in the ischemic hemisphere, with predominance in the cerebral cortex, especially in the penumbra.

CONCLUSIONS

Our results suggest that hsp70.1 plays an important role in the early protection of the brain, at least after acute focal cerebral ischemia in mice.

Diffusion-weighted magnetic resonance in cerebral venous thrombosis

BACKGROUND

Cerebral venous thrombosis (CVT) is a cause of stroke with obscure pathophysiologic properties that differ from arterial stroke. Its main mechanisms of pathophysiology are the breakdown of the blood-brain barrier and the coexistence of cytotoxic and vasogenic edema. However, conventional magnetic resonance imaging (MRI) cannot differentiate between vasogenic and cytotoxic edema.

OBJECTIVES

To describe the diffusion-weighted imaging (DWI) findings and characterize the clinical applications of DWI in CVT.

SETTING

A tertiary referral center, neurology department.

DESIGN AND METHODS

From November 1998 to March 2001, 14 patients (5 men, 9 women; mean age, 43 +/- 10 years) with CVT underwent DWI, conventional MRI, MR venography, or conventional cerebral angiography. Abnormal findings on DWI and conventional MRI indicated the necessity of MR venography and conventional angiography to confirm the diagnosis of CVT. Apparent diffusion coefficient (ADC) values were measured in all of the abnormal lesions with visual inspection of DWI and T2-weighted echo planar imaging.

RESULTS

Findings on DWI were grouped according to 3 patterns: (1) Heterogeneous signal intensity (SI) (10 patients) showed mixed bright high SI and low SI and the corresponding ADC values were inversely correlated to the DWI SI. The areas of prominent low SI on DWI were reversed with adequate treatment on follow-up MRI in 1 patient. (2) Multifocal high SI (3 patients) was similar to that observed in acute arterial stroke. The corresponding ADC values were decreased and DWI was performed in the acute stages. (3) Intravascular clot with high SI was found with (1 patient, also in heterogeneous SI group) or without (1 patient) parenchymal lesions. In 1 patient, DWI demonstrated T2-negative and fluid attenuated inversion recovery-negative lesions without correlative symptoms.

CONCLUSIONS

These data suggest that DWI with ADC maps can be used to discriminate between types of edema for tissue viability and to provide information about stages and diagnostic clues in CVT.

Squamous cell carcinoma of the cornea

In this paper, a case of corneal squamous cell carcinoma is reported. Invasive squamous cell carcinoma of the cornea is a rare disorder and has not been previously described in the Korean literature. In this case, the invasive squamous cell carcinoma of the cornea was treated by complete excision and cryotherapy. No evidence of metastasis or recurrence has been found since the procedure. Complete excision and adjunctive cryotherapy has become the treatment of choice because of the higher recurrence rate following a simple excision.

Monthly 5-days 5-fluorouracil and low-dose leucovorin for adjuvant chemotherapy in colon cancer

We investigated the dose-related effect of the 5-fluorouracil (5-FU)/leucovorin regimen on survival in 139 colon cancer patients with Dukes' B2 and C2 stage disease. Chemotherapy consisted of 400 mg/m(2) of 5-FU and 20 mg/m(2) of leucovorin injected daily for 5 days in every 4 weeks for a maximum of 12 cycles. The total dose of 5-FU administered per body surface area had a significant effect on the 5-year disease-free survival and 5-year overall survival in stage B2 and C2 colon cancer patients (P=0.0018, P=0.0011). Analysis with reference to the median DSDI demonstrated that there was a significant difference in 5-year survival in Dukes' C2 (P=0.0016), but survival was not affected by the dose intensity. Multivariate analysis demonstrated that only the total dose of 5-FU administered per surface area affected the 5-year disease-free survival and 5-year overall survival (P=0.0016, P=0.0007, respectively). It can be concluded that the total dose of 5-FU administered is important in planned dosage schedule of adjuvant chemotherapy in colon cancer.

Sensory dermatomal representation in the medial lemniscus

BACKGROUND

Restricted sensory deficits along the somatotopic topography of the medial lemniscus rarely develop in medial medullary infarction. We describe a patient with medial medullary infarction who presented with dermatomal sensory deficits caused by a medial lemniscal lesion.

CASE DESCRIPTION

A 58-year-old man presented with sudden right-sided hemiparesis and paresthesia. He had noticed the paresthesia below the level of the right L5 dermatome, where his vibration and position senses were mildly diminished. His paresthesia was more severe over the right calf and foot. Magnetic resonance images of the brain showed an acute small infarct in the medial-ventral portion of the left rostral medulla oblongata. A nerve conduction study and electromyography showed no abnormalities. At follow-up, the patient's motor and sensory deficits had improved considerably.

CONCLUSIONS

The patient showed lemniscal sensory deficits below the right L5 dermatome that were caused by the partial involvement of the medial lemniscus. These findings suggest that lemniscal sensory dermatomal representation is preserved at least up to the level of the medulla oblongata.

Cerebral venous thrombosis associated with tentorial subdural hematoma during oxymetholone therapy

Androgen was reported to cause cerebral venous thrombosis (CVT) during replacement therapy for aplastic anemia. Oxymetholone, a synthetic androgen analogue, has been widely used in the treatment of aplastic anemia. A 40-year-old woman with aplastic anemia visited our hospital because of severe headache, nausea, vomiting, blurred vision and diplopia for a period of 1 month. She had taken oxymetholone for 2 years. Neurological examination revealed bilateral papilledema and bilateral sixth nerve palsies. Brain magnetic resonance imaging (MRI), performed at the time of admission, demonstrated left-sided tentorial SDH, and focal cerebral thrombosis of the left superficial sylvian vein and sigmoid sinus. MR venography revealed multiple irregularities in the superior sagittal sinus and left transverse sinus. CVT with tentorial subdural hematoma (SDH) caused by oxymetholone was strongly suggested. Oxymetholone was immediately discontinued, and her symptoms and signs disappeared. Because of the thrombocytopenia, anticoagulation was not started. She was discharged and visited the outpatient clinic without neurological symptoms for 6 months. This report supports the cautions given about the risk of CVT with oxymetholone supplementation in aplastic anemia. To the best of our knowledge, this is the first report of CVT associated with tentorial SDH that was probably caused by oxymetholone.

Early postoperative intraperitoneal chemotherapy with mitomycin C, 5-fluorouracil and cisplatin for advanced gastric cancer

OBJECTIVE

The long-term survival of patients who undergo surgery for stage IV gastric cancer is poor, due to metastatic spread of the tumor. Intraperitoneal chemotherapy (IPT) as a possible treatment for peritoneal dissemination has been investigated in a number of different tumors. The aim of this study was to investigate the toxicity and impact of early postoperative IPT on the survival of patients with advanced gastric cancer.

METHODS

Between 1993 and 1997, a total of 91 patients with stage IV gastric cancer who underwent potentially curative or palliative resection received intraperitoneal mitomycin C before closure of the abdominal wound. 5-Fluorouracil and cisplatin were administered intraperitoneally on postoperative days 1-4, and this was repeated at 4-week intervals.

RESULTS

All patients received a median of 3 IPT perfusions. There were 24 (26.4%) postoperative complications and 1 (1.1%) mortality. The most frequent hematologic toxicity (grade 3-4) was leukopenia. The major nonhematologic toxicities (grade 3-4) were emesis and nephrotoxicity. After a median follow-up period of 26 months, 14 patients remain alive without evidence of recurrence, whereas 75 patients died due to recurrence or progression of disease. The median survival period for all 91 patients was 15.4 months. When survival according to the residual tumor was analyzed, median survival was 36.0 months in the R0 (curative resection) group, 20.6 months in the R1 group (margins of resected specimens showing microscopic residual tumor or diameter of each residual tumor less than 3 mm) and 9.0 months in the R2 group (macroscopic residual tumor larger than 3 mm) (p < 0.001).

CONCLUSIONS

IPT was found to be safe, and it appears to improve the prognosis in patients with minimal residual tumors. However, complete cytoreductive surgery is mandatory for achieving the beneficial effect of IPT.

Intravenous 5-fluorouracil versus oral doxifluridine as preoperative concurrent chemoradiation for locally advanced rectal cancer: prospective randomized trials

BACKGROUND

Preoperative radiation treatment with concomitant intravenous infusion of 5-fluorouracil (5-FU) is known to be effective in shrinking and downstaging of tumors. However, chemotherapy has often been limited by its toxicity and poor patient compliance. Oral 5-FU is known to have several advantages over conventional intravenous 5-FU infusion such as lower toxicity and higher quality of life without compromising the efficacy of the treatment. The aim of this study was to compare intravenous 5-FU with oral doxifluridine with respect to tumor response, toxicity and quality of life.

METHODS

Twenty-eight patients with rectal cancer, staged as over T3N1 or T4 by transrectal ultrasonography between July 1997 and December 1998, were included in this study. Intravenous 5-FU (450 mg/m2) and leucovorin (20 mg/m2) were given for five consecutive days during the first and fifth weeks of radiation therapy (50.4 Gy) (n = 14). Oral doxifluridine (700 mg/m2/day) and leucovorin (20 mg/m2) were given daily during radiation treatment (n = 14). Quality of life was scored according to 22 activity items (good, >77; fair, >58; poor, <57). Surgical resection was performed 4 weeks after completion of concurrent chemoradiation treatment. Tumor response was classified into CR (complete remission), PR (partial response; 50% diminution of tumor volume or downstaging ) and NR (no response).

RESULTS

Tumor response was CR 3/14 (21.4%), PR 7/14 (50%) and NR 4/14 (28.6%) in the IV arm versus CR 2/14 (14.2%), PR 6/14 (42.9%) and NR 6/14 (42.9%) in the Oral arm (p = 0.16, 0.23, 0.24), respectively. The quality of life was poor (36.4% versus 33.3%), fair and good (63.6% versus 66.7%) between the IV arm and Oral arm, respectively. Gastrointestinal toxicity was 2/14 (14.3%) in the IV arm versus 5/14 (35.7%) in the Oral arm, respectively. Stomatitis was only observed in the IV arm (1/14, 7.1%). Hematological toxicity was 3/14 (21.4%) in the IV arm versus 4/14 (28.5%) in the Oral arm, respectively. Systemic recurrence during the follow-up periods were 1/14 (7.1%) in the IV arm and 2/14 (14.3%) in the Oral arm, respectively (p = 0.307). One local recurrence was observed in the Oral arm.

CONCLUSION

Even though the results were not entirely reliable owing to the small number of patients enrolled, oral doxifluridine-based chemotherapy as preoperative chemoradiation for advanced rectal cancer did not show any significant advantages over intravenous infusion.

Intracranial cerebral artery disease as a risk factor for central nervous system complications of coronary artery bypass graft surgery

BACKGROUND AND PURPOSE

Although extracranial carotid artery disease (ECAD) is accepted as a risk factor for central nervous system (CNS) complications after coronary artery bypass graft (CABG) surgery, it remains to be clarified whether intracranial cerebral artery disease (ICAD) may also increase the risk. We conducted a prospective study to elucidate the relation between ICAD and CNS complications after CABG surgery.

METHODS

We prospectively studied 201 patients undergoing nonemergency isolated CABG surgery during a 39-month period (from March 1995 to June 1998). Each patient was evaluated before surgery with neurological examination, transcranial Doppler, and carotid duplex ultrasonography. Magnetic resonance angiography was used to determine the presence and severity of ECAD and ICAD in patients with abnormal findings on clinical examination, carotid duplex ultrasonography, or transcranial Doppler. Patients were followed after surgery and evaluated for the development of CNS complications. Association between CNS complications and their potential predictors was analyzed.

RESULTS

One hundred nine patients (54.2%) were found to have ECAD and/or ICAD. ECAD alone was found in 48 patients (23.9%), ICAD alone in 33 (16.4%), and both ECAD and ICAD in 28 (13.9%). Fifty-one patients (25.4%) had single or multiple CNS complications: 23 (11.4%) had delirium; 18 (9.0%) had hypoxic-metabolic encephalopathy; 7 (3.5%) had stroke; and 7 (3. 5%) had seizure. In multivariate analysis, ICAD was found to have an independent association with the development of CNS complications (prevalence OR, 2.28; 95% CI, 1.04 to 5.01) after controlling for covariates including age, occurrence of intraoperative events, and reoperation. The joint effect of ECAD and ICAD was also statistically significant and stronger than ICAD alone (prevalence OR, 3.87; 95% CI, 1.80 to 6.52).

CONCLUSIONS

Our results suggest that ICAD may be an independent risk factor for CNS complications after CABG surgery. These results support pre-CABG evaluation of the intracranial arteries for the risk assessment of CABG surgery, at least in black and Asian patients, in whom there may be a higher prevalence of intracranial arterial stenosis.

Scrub typhus encephalomyelitis with prominent focal neurologic signs

BACKGROUND

Encephalomyelitis with prominent focal neurologic signs and associated neuroradiologic abnormalities has not been previously described in scrub typhus.

CASE DESCRIPTION

A 22-year-old woman was admitted because of fever and an altered mental state. Neurologic examination revealed bilateral sixth and seventh nerve palsies, bilateral gaze evoked nystagmus, anarthria, dysphagia, quadriparesis, and sensory level at T1. Serum and cerebrospinal fluid samples were positive for tsutsugamushi antibody. The patient's magnetic resonance images demonstrated the lesions responsible for the neurologic dysfunctions: in the lower brainstem, cerebellar peduncles, and spinal cord. It was interesting that the gray matter of the spinal cord was predominantly involved.

CONCLUSIONS

The recognition of unusual manifestations and the clinical suspicion of this treatment-responsive disease may be important, particularly in the face of increasing international and intranational travel.

Neuroprotective effect of low dose riluzole in gerbil model of transient global ischemia

Riluzole is a neuroprotective agent the efficacy of which was proven in amyotrophic lateral sclerosis in human and in animal models of cerebral ischemia. However, the dosage used in animal experiments was much higher than that in human. We investigated the efficacy of low dose riluzole, which was similar to the dose used in human trials, in animal model of global ischemia. Global ischemia was induced in male Mongolian gerbils for 5min under monitoring of rectal temperature. Riluzole (0.8 mg/kg) were injected intraperitoneally 30min before ischemia. Seven days after ischemia, animals were decapitated and surviving nerve cells in hippocampal CA1 area were quantified. The number of surviving cells was compared between in riluzole-treated and control groups and the former showed statistically significant better survivals than the latter (P<0.001).

Diffusion-weighted imaging in Wallerian degeneration

We report two patients displaying hyperintensities on diffusion-weighted imaging (DWI) in the area of Wallerian degeneration (WD) at 12 days after stroke. High signal intensities were more conspicuous on DWI than on T2-weighted images. Both patients showed decreased diffusion anisotropy resulting in elevated apparent diffusion coefficient in the area of WD. These patients illustrate that DWI may be useful in the detection of the early stage of WD.

Tissue urokinase-type plasminogen activator receptor levels in breast cancer

Cancer invasion is induced by several proteolytic enzyme systems associated with the destruction of basement membrane and extracellular matrix. Urokinase-type plasminogen activator (uPA) and plasminogen activator inhibitor-1 (PAI-1) have been reported as prognostic factors in breast cancer patients and plasminogen activation is regulated by various factors such as uPAR and growth factors. Thus, we examined the tissue levels of urokinase-type plasminogen activator receptor (uPAR) in breast cancer patients. Tissue uPAR levels were measured by ELISA assay in 268 breast cancer patients. The median and mean values of tissue uPAR level in breast cancer were 3.5 ng/mg cytosol protein and 4.8+/-3.6 ng/mg cytosol protein, respectively. Tissue uPAR level was the highest in T1 stage, but there was no statistical significance between the T stages (p>0.05), nor in nodal stage, in the value of uPAR according to progression. And the value of uPAR expression was not associated with estrogen and progesterone receptor status, number of involved node and percent of node involvement. In TNM stage, tissue uPAR levels were higher in patients with stage I-II than in patients with stage III-IV (p=0.027). In univariate analysis, nodal factor (p=0.002) and TNM stage (p=0.0004) were significant. But, multivariate analysis showed that TNM stage was the only significant prognostic factor (p=0.0002). These results suggest that uPAR is mainly associated with initial tumor invasion and other factors might be involved in later stages of cancer progression.

Transduction effect of antisense K-ras on malignant phenotypes in gastric cancer cells

The antitumoral effects of antisense RNA to K-ras were investigated in gastric cancer cell lines by examining the level of K-ras expression and the tumorigenicity in vitro and in vivo. Polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP), DNA sequencing, and immunoblotting analysis revealed that YCC-1 gastric cancer cells overexpressed wild type K-ras, whereas YCC-2 cells had a homozygous mutation in codon 12 from GGT (glycine) to AGT (serine), while SNU-1 cells had a heterozygous mutation to GAT (asparagine) in the identical position. Both YCC-1 and YCC-2 cells were transduced by LNC-AS/K-ras containing the antisense 2.2 kb genomic K-ras DNA fragment covering exon 2 and exon 3 specific for K-ras. The application of antisense K-ras significantly downregulated the expression of K-ras and had no influence on the expression of either H-ras or N-ras. The antisense-transduced YCC-2 cells grew considerably slower than the control group transduced by LNCX, whereas the growth inhibition of antisense-transduced YCC-1 cells was less prominent than that of transduced YCC-2 cells. In addition, the tumorigenicity of YCC-2 cells transduced by LNC-AS/K-ras was totally lost. Therefore, our results imply that the specific inhibition of K-ras p21 protein can be accomplished by introducing the antisense covering the K-ras- specific region to gastric cancer cells with aberrant K-ras expression, resulting in a reduction of the growth rate and suppression of tumorigenicity.

Acute bilateral cerebellar infarcts in the territory of posterior inferior cerebellar artery

The authors report 12 patients with acute bilateral cerebellar infarcts in posterior inferior cerebellar artery (PICA) territory. They found three topographic patterns: A) bilateral medial PICA in six patients; B) unilateral whole + contralateral medial PICA in four; and C) bilateral small multiple in two. Nine patients in Groups A and B had unilateral PICA or vertebral artery disease, and both patients in Group C had bilateral vertebral artery disease. These findings support that unilateral supply to both medial PICA territories may be the most relevant pathogenesis of this syndrome.

Combined peripheral facial and abducens nerve palsy caused by caudal tegmental pontine infarction

Isolated peripheral facial and abducens nerve palsy could theoretically be caused by a caudal pontine infarction, but as far as we know, there has been no published case history which has demonstrated this point. We describe the cases of two hypertensive patients who showed combined peripheral facial and abducens nerve palsy without other neurologic symptoms or signs. Other than hypertension, there was no identifiable etiology. Magnetic resonance imaging demonstrated compatible isolated ipsilateral ischemic infarction of the caudal tegmental pons. The present cases indicate that a well-placed small pontine infarction can cause isolated peripheral facial and abducens nerve palsy.

Hypoglycemia-induced cerebellar dysfunction and quantitative positron emission tomography study

OBJECTIVE

To describe an unusual case of hypoglycemia-induced bilateral cerebellar dysfunction.

BACKGROUND

The cerebellum is known to be resistant to hypoglycemia, and selective cerebellar dysfunction caused by hypoglycemia has not been reported. Previous studies showed that the ratio between the rate constants for glucose uptake and phosphorylation (K1 and k3) is reversed in the cerebellum compared with the cerebral cortex; higher K1 in the cerebellum and higher k3 in the cerebral cortex.

METHODS

Quantitative dynamic PET scanning with labeled fluorodeoxyglucose (18F-FDG) was performed to prove altered glucose kinetics in the cerebellum of a patient who presented with episodic cerebellar dysfunction associated with hypoglycemia. Four control subjects underwent the same study.

RESULTS

The ratio between K1 and k3 was not reversed in the cerebellum of our patient (K1 = 0.082, k3 = 0.192). On the contrary, the ratio was reversed in the control subjects (mean K1 = 0.109, mean k3 = 0.080). In addition, the patient's cerebellar metabolic rate of glucose (rCMRglu = 27.9 micromol/100 g/minute) and the rate constant of glucose egress (k2 = 0.543) were relatively increased compared with those of control subjects (mean rCMRglu = 21.9 micromol/100 g/minute, mean k2 = 0.352).

CONCLUSIONS

In a case of episodic bilateral cerebellar dysfunction caused by hypoglycemia, quantitative dynamic PET study demonstrated decreased glucose uptake-to-utilization ratio and increased leak of glucose in the cerebellum. The cerebellum is not invariably resistant to hypoglycemia.