Long insular artery damage might be a key sign for predicting functional prognosis of putaminal hemorrhage

OBJECTIVE

Although the putamen is the most common area of spontaneous intracerebral hemorrhage, previous reports about the effects of surgery are limited. We sometimes experience a poor prognosis in patients in whom there is no damage to the internal capsule, but with injury in the long insular artery (LIA) region. The purpose of this study was to confirm the relationship between LIA damage and patient prognosis following surgery for putaminal hemorrhage.

METHODS

We retrospectively collected data of 287 surgical cases who presented with putaminal hemorrhage between January 2004 and March 2022. Among them, we chose patients without initial damage to the posterior limb of the internal capsule, and divided these patients into two groups, those without (Group A) and with (Group B) final damage in the LIA region. We compared positivity rates of final manual muscle test (MMT) scores≥3 and related factors.

RESULTS

Sixty-three of the 287 patients were included in this study. Of them, 11 cases in Group A were positive for MMT scores≥3 (68.8%) and 9 cases (19.1%) in Group B had MMT scores≥3 seven days after surgery. Group A thus had a significantly higher rate of MMT scores≥3 than group B (p=0.00).

CONCLUSION

In patients without initial damage to the internal capsule, LIA injury might be a key sign for predicting the functional prognosis of putaminal hemorrhage.

Hemichorea associated with cavernous angioma and a small errhysis: A case report and literature review

RATIONALE

Chorea is a movement disorder characterized by randomly appearing involuntary movements of the face, neck, limbs, or trunk. Hemichorea is unilateral, involving one side of the body. Hemichorea is commonly caused by non-ketotic hyperglycemia and/or cerebrovascular injury to the contralateral basal ganglia.

PATIENT CONCERNS

Here, we report the case of a patient diagnosed with hemichorea who had diabetes, cavernous angioma, and a small intracranial errhysis. Routine testing showed the patient's blood glucose level was slightly higher than the normal range.

INTERVENTIONS

The errhysis was too small to be treated.

DIAGNOSES

Brain magnetic resonance imaging showed a cavernous angioma with a small errhysis in the right putamen.

OUTCOMES

Hemichorea was completely resolved after 4 months.

LESSONS

If diabetes is well controlled and imaging indicates brain lesions suggestive of a recent stroke, a diagnosis of post-stroke hemichorea should be considered.

MDMA (Ecstasy) association with impaired fMRI BOLD thalamic coherence and functional connectivity

BACKGROUND

MDMA exposure is associated with chronic serotonergic dysfunction in preclinical and clinical studies. A recent functional magnetic resonance imaging (fMRI) comparison of past MDMA users to non-MDMA-using controls revealed increased spatial extent and amplitude of activation in the supplementary motor area during motor tasks (Karageorgiou et al., 2009). Blood oxygenation level dependent (BOLD) data from that study were reanalyzed for intraregional coherence and for inter-regional temporal correlations between time series, as functional connectivity.

METHODS

Fourteen MDMA users and ten controls reporting similar non-MDMA abuse performed finger taps during fMRI. Fourteen motor pathway regions plus a pontine raphé region were examined. Coherence was expressed as percent of voxels positively correlated with an intraregional index voxel. Functional connectivity was determined using wavelet correlations.

RESULTS

Intraregional thalamic coherence was significantly diminished at low frequencies in MDMA users compared to controls (p=0.009). Inter-regional functional connectivity was significantly weaker for right thalamo - left caudate (p=0.002), right thalamo - left thalamus (p=0.007), right caudate - right postcentral (p=0.007) and right supplementary motor area - right precentral gyrus (p=0.011) region pairs compared to controls. When stratified by lifetime exposure, significant negative associations were observed between cumulative MDMA use and functional connectivity in seven other region-pairs, while only one region-pair showed a positive association.

CONCLUSIONS

Reported prior MDMA use was associated with deficits in BOLD intraregional coherence and inter-regional functional connectivity, even among functionally robust pathways involving motor regions. This suggests that MDMA use is associated with long-lasting effects on brain neurophysiology beyond the cognitive domain.

Arterial vascularisation of the anterior perforated substance

INTRODUCTION

The arteries of the anterior perforated substance (APS) are important due to their role in supplying blood to important internal structures such as the internal capsule, putamen and caudate nucleus. The purpose of this study was to investigate in detail the arteries of the APS.

METHODS

The arteries of the APS were investigated in 60 cerebral hemispheres from 30 adult cadaveric brains. The internal carotid arteries were cannulated and perfused with coloured latex. The branches of the middle cerebral artery (MCA) penetrating the APS were investigated. These arteries, known as the lateral lenticulostriate arteries and originating from the M1 segment, early temporal and early frontal branches of the MCA, were recorded.

RESULTS

The branches of the anterior choroidal artery, which reached the APS, were seen in all specimens. We found one to three branches that arose from the A2 segment of the anterior cerebral artery (ACA) to the APS in all hemispheres, and one to three branches that originated from the A1 segment of the ACA in 48 hemispheres. In addition, two accessory MCAs that originated from the A2 segment of the ACA were recorded as variations, and perforating branches to the APS were observed.

CONCLUSION

Serious complications like motor deficits can occur as a result of injury to the arteries of the APS. Hence, neurosurgeons performing operations such as aneurysm or insular tumour surgeries must be aware of the importance of preserving these arteries.

Gender difference in neural response to psychological stress

Gender is an important biological determinant of vulnerability to psychosocial stress. We used perfusion based functional magnetic resonance imaging (fMRI) to measure cerebral blood flow (CBF) responses to mild to moderate stress in 32 healthy people (16 males and 16 females). Psychological stress was elicited using mental arithmetic tasks under varying pressure. Stress in men was associated with CBF increase in the right prefrontal cortex (RPFC) and CBF reduction in the left orbitofrontal cortex (LOrF), a robust response that persisted beyond the stress task period. In contrast, stress in women primarily activated the limbic system, including the ventral striatum, putamen, insula and cingulate cortex. The asymmetric prefrontal activity in males was associated with a physiological index of stress responses-salivary cortisol, whereas the female limbic activation showed a lower degree of correlations with cortisol. Conjunction analyses indicated only a small degree of overlap between the stress networks in men and women at the threshold level of P < 0.01. Increased overlap of stress networks between the two genders was revealed when the threshold for conjunction analyses was relaxed to P < 0.05. Further, machine classification was used to differentiate the central stress responses between the two genders with over 94% accuracy. Our study may represent an initial step in uncovering the neurobiological basis underlying the contrasting health consequences of psychosocial stress in men and women.

Acupuncture of LI-4 in Anesthetized Healthy Humans Decreases Cerebral Blood Flow in the Putamen Measured with Positron Emission Tomography

To minimize the influence of exogenous factors, 13 volunteers were anesthetized with sevoflurane 1 MAC while exposed to manual acupuncture stimulation of LI-4 (Group 1, n = 7) or a placebo point in the space between the third and fourth metacarpals (Group II, n = 6). During anesthesia (baseline) and anesthesia + acupuncture, one H2(15)O scan was performed, respectively. Group I demonstrated a significant decrease in regional cerebral blood flow in the right medial frontal gyrus (20%) and in the left putamen (17%). In Group II regional cerebral blood flow was decreased in the right medial frontal gyrus (22%); in the putamen no significant changes were observed. These data suggest that needle penetration of the skin affects the medial frontal gyrus, whereas acupuncture of LI-4 influences the putamen.

Perimesencephalic Non-aneurysmal Subarachnoid Hemorrhage Caused by Cavernous Sinus Thrombosis-Case Report-

A 37-year-old man presented with perimesencephalic non-aneurysmal subarachnoid hemorrhage associated with cavernous sinus thrombosis. Anticoagulant therapy was administered to treat the cavernous sinus thrombosis, but provoked severe intracranial hemorrhage, severely disabling the patient. Perimesencephalic non-aneurysmal subarachnoid hemorrhage is a benign clinical entity with generally good prognosis, but the association with cavernous sinus thrombosis requires careful investigation prior to treatment.

Evaluation of basal ganglia haemodynamic changes with perfusion–weighted magnetic resonance imaging in patients with Parkinson’s disease

PURPOSE

The aim of our study was to assess the regional cerebral blood flow (rCBF) of basal ganglia and thalami in patients with Parkinson's disease (PD) using perfusion-weighted magnetic resonance imaging (PW-MRI).

MATERIAL AND METHODS

Twenty subjects affected by idiopathic PD according to the United Kingdom Brain Bank criteria were enrolled in the study. Twenty normal subjects matched for age and gender were included as controls. After 20-day therapy withdrawal, the PD patients underwent PW-MRI. The rCBF was calculated both in patients and in controls. The regions of interest were manually positioned on rCBF maps over the caudate nucleus, the putamen, the external and internal globus pallidus, and over the ventrolateral nucleus of the thalamus. Data were normalised with those obtained from parieto-occipital white matter (POWM). Statistical analysis was performed using a parametric ANOVA test.

RESULTS

Patients showed a significant (p<0.01) interhemispheric asymmetry; rCBF values were higher on the more severely affected side. Controls showed no interhemispheric asymmetry.

CONCLUSION

Our study suggests that PW-MRI is a valuable tool for assessing haemodynamic changes in PD patients. Haemodynamic change pattern may be useful in the early diagnosis of PD.

Silent microbleeds are associated with volume of primary intracerebral hemorrhage

The authors performed a correlative radiologic study on the micro-bleeds and volume of intracerebral hemorrhage in the supratentorial ICH patients. In the patients with lobar or putaminal hemorrhage, the hemorrhage volumes increased more than twofold or threefold in the patients with micro-bleeds. Moreover, the presence of microbleeds was an independent risk factor for large-sized hemorrhage. These data show that microbleeds may be associated with a larger ICH volume.

Brain activation during craving for alcohol measured by positron emission tomography

OBJECTIVE

Craving for alcohol is probably involved in acquisition and maintenance of alcohol dependence to a substantial degree. However, the brain substrates and mechanisms that underlie alcohol craving await more detailed elucidation.

METHOD

Positron emission tomography was used to map regional cerebral blood flow (CBF) in 21 detoxified patients with alcohol dependence during exposure to alcoholic and non-alcoholic beverages.

RESULTS

During the alcohol condition compared with the control condition, significantly increased CBF was found in the ventral putamen. Additionally, activated areas included insula, dorsolateral prefrontal cortex and cerebellum. Cerebral blood flow increase in these regions was related to self-reports of craving assessed in the alcoholic patients.

CONCLUSIONS

In this investigation, cue-induced alcohol craving was associated with activation of brain regions particularly involved in brain reward mechanisms, memory and attentional processes. These results are consistent with studies on craving for other addictive substances and may offer strategies for more elaborate studies on the neurobiology of addiction.

Effects of the perivascular space on convection-enhanced delivery of liposomes in primate putamen

Convection-enhanced delivery has recently entered the clinic and represents a promising new therapeutic option in the field of neurodegenerative diseases and treatment of brain tumors. Understanding of the principles governing delivery and flow of macromolecules within the CNS is still poorly understood and requires more investigation of the microanatomy and fluid dynamics of the brain. Our previously established, reflux-free convection-enhanced delivery (CED) technique and real-time imaging MR method for monitoring CED delivery of liposomes in primate CNS allowed us to closely monitor infusions of putamen. Our findings indicate that CED in putamen is associated with perivascular transport of liposomes, throughout CNS arteries. The results may explain side effects seen in current clinical trials using CED. In addition, they clearly show the necessity for a monitoring technique for future direct delivery of therapeutic agents to the human central nervous system. Based on these findings, we believe that the physiological concept that the perivascular space serves as a conduit for distribution of endogenous molecules within the CNS also applies to interstitially infused agents.

fMRI reveals two distinct cerebral networks subserving speech motor control

BACKGROUND

There are few data on the cerebral organization of motor aspects of speech production and the pathomechanisms of dysarthric deficits subsequent to brain lesions and diseases. The authors used fMRI to further examine the neural basis of speech motor control.

METHODS AND RESULTS

In eight healthy volunteers, fMRI was performed during syllable repetitions synchronized to click trains (2 to 6 Hz; vs a passive listening task). Bilateral hemodynamic responses emerged at the level of the mesiofrontal and sensorimotor cortex, putamen/pallidum, thalamus, and cerebellum (two distinct activation spots at either side). In contrast, dorsolateral premotor cortex and anterior insula showed left-sided activation. Calculation of rate/response functions revealed a negative linear relationship between repetition frequency and blood oxygen level-dependent (BOLD) signal change within the striatum, whereas both cerebellar hemispheres exhibited a step-wise increase of activation at approximately 3 Hz. Analysis of the temporal dynamics of the BOLD effect found the various cortical and subcortical brain regions engaged in speech motor control to be organized into two separate networks (medial and dorsolateral premotor cortex, anterior insula, and superior cerebellum vs sensorimotor cortex, basal ganglia, and inferior cerebellum).

CONCLUSION

These data provide evidence for two levels of speech motor control bound, most presumably, to motor preparation and execution processes. They also help to explain clinical observations such as an unimpaired or even accelerated speaking rate in Parkinson disease and slowed speech tempo, which does not fall below a rate of 3 Hz, in cerebellar disorders.

Comparison of cerebral blood flow between perfusion computed tomography and xenon-enhanced computed tomography for normal subjects: territorial analysis

OBJECTIVE

The purpose of this study was to clarify the difference between cerebral blood flow (CBF) by perfusion computed tomography (CT) and that by xenon-enhanced CT (Xe-CT) through simultaneous measurement.

METHODS

Xenon-enhanced CT and perfusion CT were continually performed on 7 normal subjects. Ratios of CBF by perfusion CT (P-CBF) to CBF by Xe-CT (Xe-CBF) were measured for 5 arterial territories; 3 were territories of 3 major arteries (the anterior [ACA], middle [MCA], and posterior [PCA] cerebral arteries), and the other 2 were areas of the thalamus and putamen.

RESULTS

The ratios were 1.30 +/- 0.10, 1.26 +/- 0.15, 1.61 +/- 0.15, 0.801 +/- 0.087, and 0.798 +/- 0.080 for the ACA, MCA, PCA, thalamus, and putamen, respectively. Although a good correlation was observed between P-CBF and Xe-CBF for each territory, the ratios were significantly different (P < 0.0001) between 3 territory groups (group 1: ACA and MCA, group 2: PCA, and group 3: thalamus and putamen).

CONCLUSIONS

The difference in the ratio of P-CBF to Xe-CBF between the 3 territory groups was considered to result principally from the features of P-CBF. To evaluate P-CBF properly, its territorial characteristics should be taken into account.

A differential pattern of neural response toward sad versus happy facial expressions in major depressive disorder

BACKGROUND

Accurate recognition of facial expressions is crucial for social functioning. In depressed individuals, implicit and explicit attentional biases away from happy and toward sad stimuli have been demonstrated. These may be associated with the negative cognitions in these individuals.

METHODS

Using event-related functional magnetic resonance imaging (fMRI), neural responses to happy and sad facial expressions were measured in 14 healthy individuals and 16 individuals with major depressive disorder.

RESULTS

Healthy but not depressed individuals demonstrated linear increases in response in bilateral fusiform gyri and right putamen to expressions of increasing happiness, while depressed individuals demonstrated linear increases in response in left putamen, left parahippocampal gyrus/amygdala, and right fusiform gyrus to expressions of increasing sadness. There was a negative correlation in depressed individuals between depression severity and magnitude of neural response within right fusiform gyrus to happy expressions.

CONCLUSIONS

Our findings indicate preferential increases in neural response to sad but not happy facial expressions in neural regions involved in the processing of emotional stimuli in depressed individuals. These findings may be associated with the above pattern of implicit and explicit attentional biases in these individuals and suggest a potential neural basis for the negative cognitions and social dysfunction in major depression.

Brain T2 relaxation times correlate with regional cerebral blood volume

We previously reported cerebellar and putaminal transverse relaxation time (T2) differences in children with ADHD and in adults with childhood trauma. As brain T2 can be altered by deoxyhemoglobin concentration ([dHb]) and because [dHb] is proportional to regional cerebral blood volume (rCBV), at steady state we attributed those differences to rCBV changes. Studies in other species have established a correlation between T2 and rCBV; however this has yet to be demonstrated in human brain. Echo planar imaging (EPI) T2 relaxometry and dynamic susceptibility-contrast (DSC) MRI were used to measure T2 and rCBV in 11 healthy adults. Significant T2-rCBV correlations were observed in both cerebellar vermis and putamen (r = 0.759,p = 0.007;r = 0.782,p = 0.004, respectively). These correlations predict 9 +/- 3% and 10 +/- 3% rCBV changes, respectively, for each 1-msec change in T2. Consequently, brain T2 measurements may be useful for estimating steady-state rCBV.

Oral methylphenidate challenge selectively decreases putaminal T2 in healthy subjects

Despite the recent rise in oral methylphenidate (MPH) abuse, few studies have characterized the time course of oral MPH brain effects in human subjects. Accordingly, this study assessed the hemodynamic effects of oral MPH effects in 11 healthy young adults (six women), by measuring brain transverse relaxation times (T2). T2 can be interpreted as a surrogate marker for, and inversely correlated with, steady-state cerebral blood volume (CBV). Data were acquired from the caudate nucleus, putamen, and thalamus, using a 1.5 T MRI scanner at baseline and serially for 2 h following oral MPH administration (0.5 mg/kg). Physiological and subjective measures and plasma MPH levels also were examined. MPH induced a selective T2 decrease (-1.65+/-0.53 ms) in the putamen (F(6,54)=2.68, P<0.03). Heartrate, blood pressure and plasma MPH levels increased significantly after drug administration, as well as subjective ratings of "feeling drug effect". T2 decreases may reflect MPH-induced increases in putaminal blood volume. These data suggest that T2 relaxometry can be used to study the time course of regional cerebral blood volume responses to MPH and perhaps to other stimulant drugs.

Dystonic posturing associated with putaminal hyperperfusion depicted on subtraction SPECT

PURPOSE

Dystonic posturing (DP) is one of the most reliable lateralizing indicators for temporal lobe epilepsy (TLE). We evaluated the ictal hyperperfusional areas in patients with DP by using ictal-interictal subtraction single-photon emission computed tomography (SPECT).

METHODS

Ninety-seven patients were treated surgically for intractable TLE, and 39 patients underwent ictal and interictal SPECT studies with the same isotope. These patients were divided into three groups: group I with DP of the contralateral side extended to the epileptogenic focus, group II with elevated muscle tonus but without DP, and group III without DP or alteration of muscle tonus. Ictal, interictal SPECT and thin-slice magnetic resonance imaging (MRI) were overlaid by using the automatic multimodality registration program to construct ictal-interictal subtracted images of SPECT on MRI.

RESULTS

Thirteen patients belonged to group I; 14, to group II; and 12, to group III. A statistically significant difference in hyperperfusion rate was observed in the putamen (10 patients in group I, three in group II and two in group III; p < 0.01) and mesial temporal lobe (10 patients in group I, seven in group II, and two in group III; p < 0.05) on the ipsilateral side of the epileptogenic focus. No statistically significant difference was observed for other ictal symptoms except ipsilateral upper-limb automatism (eight patients in group I, three in group II, and none in group III; p < 0.01).

CONCLUSIONS

A strong correlation between DP and hyperperfusion in the putamen and mesial temporal lobe was demonstrated. Some patients showed a wide hyperperfusion area extending from the mesial temporal lobe to putamen, which may correspond to the propagation of epileptic discharges. Our results suggest a correlation between hyperperfusion of putamen and contralateral dystonic posturing.

Regional cerebral hyperperfusion with ictal dystonic posturing: ictal-interictal SPECT subtraction

PURPOSE

Ictal-interictal single-photon emission computed tomography (SPECT) subtraction was performed to find brain structures related to ictal dystonic posturing (DP) in patients with temporal lobe epilepsy (TLE).

METHODS

Thirty-two patients with mesial TLE who had ictal and interictal SPECTs were included. They were divided into two groups; DP group with ictal dystonia during ictal SPECT (n = 15) and Non-DP group without ictal DP (n = 17). Ictal-interictal SPECT subtraction was performed, and then subtracted SPECT was coregistered with brain spoiled gradient recalled (SPGR) magnetic resonance imaging (MRI). The ictal hyperperfusion on subtracted SPECT was analyzed in basal ganglia, frontal cortex, thalamus, temporal lobe, and insular cortex.

RESULTS

The incidences of ictal hyperperfusion on brain regions in DP versus Non-DP groups were 80.0% (12 of 15 patients) versus none (0 of 17), p = 0.001, chi2, in caudate nucleus; 93.3% (14 of 15) versus 47.0% (eight of 17), p = 0.005, in putamen; and 80.0% (12 of 15) versus 41.2% (seven of 17), p = 0.026, in thalamus. No significant difference of ictal hyperperfusion was found in globus pallidus, temporal lobes, insular and frontal cortices between DP and Non-DP groups. DP patients showed an earlier age at seizure onset [8.6 years (DP) vs. 15.7 years (Non-DP) (p = 0.015)] and a longer duration of seizure history [19.0 years (DP) vs. 11.9 years (Non-DP) (p = 0.015)].

CONCLUSIONS

Caudate nucleus, putamen, and thalamus were significantly related to the ictal DP during TLE seizures. Our study showed first an active involvement of the caudate nucleus in the generation of ictal DP.

Normal pressure hydrocephalus and cerebral blood flow: a PET study of baseline values

Regional cerebral blood flow (CBF) was studied with O(15)-water positron emission tomography and anatomic region-of-interest analysis on co-registered magnetic resonance in patients with idiopathic (n = 12) and secondary (n = 5) normal pressure hydrocephalus (NPH). Mean CBF was compared with values obtained from healthy volunteers (n = 12) and with clinical parameters. Mean CBF was significantly decreased in the cerebrum and cerebellum of patients with NPH. The regional analysis demonstrated that CBF was reduced in the basal ganglia and the thalamus but not in white matter regions. The results suggest that the role of the basal ganglia and thalamus in NPH may be more prominent than currently appreciated. The implications for theories regarding the pathogenesis of NPH are discussed.

Alcohol misuse: a risk factor for putaminal damage by ischemic brain infarct?

The relationship between alcohol consumption and the risk of ischemic stroke has been widely studied, whereas the effect of alcohol use on stroke features is not well established. This study compared the clinical and stroke features of ischemic stroke in two groups of patients with ischemic stroke: those with a history of alcohol misuse and those with a history of more social drinking. DSM-IV criteria were used to diagnose alcohol use disorder (dependency or abuse) in 275 of 486 consecutive patients aged 55-85 years, 3-4 months after ischemic stroke. Magnetic resonance imaging of the head was performed 3 months after stroke. Alcohol use disorder was diagnosed in 37/275 (13.5%) of ischemic stroke patients. These patients had more frequently (70.3 vs. 34.5%; OR 4.5; 95% CI 2.2-9.1; p < 0.000) an infarct affecting the putamen compared with patients who indulged in more social drinking. Another predisposed area was the superior anterior cerebral artery area. The stroke due to large- artery atherosclerosis was more common in patients with alcohol use disorder. The misuse of alcohol seemed to be associated with cerebral infarct localization in the putamen and superior anterior cerebral artery area. Prospective studies are needed to verify our preliminary finding.

Arm chorea secondary to an unruptured giant aneurysm

We describe the case of a 20-year-old male who developed right-arm choreic movements secondary to a giant unruptured aneurysm impinging upon the left thalamus, putamen, globus pallidus, cerebral peduncle, midbrain, and subthalamic nucleus. The aneurysm was treated successfully with coils and a supraclinoid balloon. Abnormal movements initially failed to ameliorate, but within a few months, it was possible to discontinue symptomatic haloperidol therapy, with only mild residual abnormal movements.

Positron emission tomography of striatal serotonin transporters in Parkinson disease

BACKGROUND

Little is known about serotonin neurons in Parkinson disease (PD).

OBJECTIVE

To study the serotonin system in PD with positron emission tomography, using the serotonin transporter radioligand [11C](+)McN5652.

DESIGN AND PATIENTS

We measured the density of the serotonin transporter and the density of [11C]WIN35,428-labeled dopamine transporters in the striatum of 13 adults with PD and 13 age- and sex-matched controls. To assess the effects of possible differences in blood flow or brain atrophy, we also measured regional cerebral blood flow and the size of the regions of interest for the caudate nucleus and putamen.

RESULTS

Patients with PD showed reductions in the specific distribution volumes of [11C](+)McN5652 in the caudate (P<.01) and putamen (P<.01), along with the expected reductions in striatal [11C]WIN35,428 binding (P<.01). There were no reductions in regional cerebral blood flow or the sizes of the regions of interest, mitigating against potential confounding effects of blood flow, brain atrophy, or partial volume effects. Reductions in serotonin transporter binding correlated with ratings of disease staging.

CONCLUSIONS

These results suggest that the density of serotonin transporters, like that of dopamine transporters, is reduced in the striatum of patients with PD and that these changes are related to disease stage.

Type I glutaric aciduria, part 1: natural history of 77 patients

Type I glutaric aciduria (GA1) results from mitochondrial matrix flavoprotein glutaryl-CoA dehydrogenase deficiency and is a cause of acute striatal necrosis in infancy. We present detailed clinical, neuroradiologic, molecular, biochemical, and functional data on 77 patients with GA1 representative of a 14-year clinical experience. Microencephalic macrocephaly at birth is the earliest sign of GA1 and is associated with stretched bridging veins that can be a cause of subdural hematoma and acute retinal hemorrhage. Acute striatal necrosis during infancy is the principal cause of morbidity and mortality and leads to chronic oromotor, gastroesophageal, skeletal, and respiratory complications of dystonia. Injury to the putamen is heralded by abrupt-onset behavioral arrest. Tissue degeneration is stroke-like in pace, radiologic appearance, and irreversibility. It is uniformly symmetric, regionally selective, confined to children under 18 months of age, and occurs almost always during an infectious illness. Our knowledge of disease mechanisms, though incomplete, is sufficient to allow a rational approach to management of encephalopathic crises. Screening of asymptomatic newborns with GA1 followed by thoughtful prospective care reduces the incidence of radiologically and clinically evident basal ganglia injury from approximately 90% to 35%. Uninjured children have good developmental outcomes and thrive within Amish and non-Amish communities.

Chronological changes of perihematomal edema of human intracerebral hematoma

Recent investigations have indicated the importance of secondary brain damage in the pathophysiology of intracerebral hemorrhage (ICH), which includes ischemic brain damage and edema formation around a hematoma. The purpose of the current study is to investigate chronological changes of perihematomal edema in patients with human ICH and also the correlation between volume of perihematomal edema and neurological status. Fourteen patients with medium-sized putaminal hemorrhage (29.4 +/- 13.2 ml) without hematoma enlargement were included in this study. To investigate chronological changes of perihematomal edema, we performed CT scans prospectively on the day of hemorrhage and repeated them on days 1, 3, 7, 14, and 28. We evaluated the patients neurologically using the NIH stroke scale on the day a CT scan was performed. The volume of perihematomal edema in human ICH increased rapidly three days after hemorrhage and the score on the NIH stroke scale showed a deterioration. The volume of perihematomal edema then increased slowly until day 14 after hemorrhage, and decreased thereafter. Despite progression of perihematomal edema, the score on the NIH stroke scale improved gradually after day 3.

Aphasia following left putaminal hemorrhage. Statistical analysis of factors affecting prognosis

Multivariate and single variable analyses were employed to investigate the recovery mode of aphasia in right-handed patients with putaminal hemorrhage on the left side. Speech disturbance was evaluated using the standard language test for aphasia (SLTA) at intervals of 1, 3 and 6 months after the ictus. Recovery was assessed in relation to age, gender, volume and location of hematoma, and treatment modalities. Extension of the hematoma into the corona radiata was the factor that dominated the prognosis of aphasia at all intervals during the follow-up period. Good recovery was documented in patients with less than 2 cm2 of the hematoma volume located in the corona radiata. Recovery was poor, however, in patients with more than 12 cm2 of the hematoma in the corona radiata. While aphasia continued to improve over 6 months after the ictus, recovery was more prominent in the first 3 months. Our study precisely demonstrated that the extension into the corona radiata independently and strongly influenced the outcome of aphasia in patients with left putaminal hemorrhage.

The effects of neuroleptic medications on basal ganglia blood flow in schizophreniform disorders: a comparison between the neuroleptic-naïve and medicated states

BACKGROUND

Previous studies indicate that basal ganglia volumes of first-episode neuroleptic-naïve patients with schizophrenia are smaller than those of normal control subjects. Subsequent exposure to neuroleptic medication appears to induce volumetric change. Possible reasons for this include differences in blood flow and metabolism between the neuroleptic-naïve and medicated states.

METHODS

We used positron emission tomography (PET) to measure blood flow to the caudate and putamen, in a sample of 29 neuroleptic-naïve patients with schizophreniform disorders and 29 matched control subjects. We also studied a subset of the patient sample (n = 13), comparing their "before" versus "on" medication PET scans.

RESULTS

We did not find a significant difference in blood flow to the caudate and putamen between neuroleptic-naïve patients and control subjects even after controlling for whole brain blood flow; however, in the subset of 13 patients compared in the "on" versus "off" medication states, there was a statistically significant increase in blood flow to both the caudate and putamen.

CONCLUSIONS

Before treatment, there appears to be no difference in striatal blood flow between first-episode neuroleptic-naïve patients and healthy volunteers, but there appears to be a significant increase in blood flow to the striatum after the treatment is initiated.

Impaired functionality of reperfused brain tissue following short transient focal ischemia in rats

Functional magnetic resonance imaging (fMRI) has been applied to study the consequences of transient focal ischemia on neuronal excitability in the rat brain. The experimental paradigm consisted of measuring the changes in local cerebral blood volume (CBV) induced by systemic infusion of the GABA(A) antagonist bicuculline after occlusion of the middle cerebral artery (MCA) for durations of 5, 15, 30 and 60 min using the intraluminal thread model. fMRI studies were carried out 60 min after successful reperfusion of the ischemic territory. Bicuculline-induced dynamic changes in local CBV were assessed in three brain regions: Parietal cortex, caudate putamen and thalamus. The measured CBV response was negatively correlated with the ischemia duration. Additionally, the three regions showed different vulnerability to the transient MCA occlusion, caudate being the most susceptible followed by parietal cortex and thalamus. The fMRI signals weakly correlated with basal CBF and CBV following reperfusion. Our results indicate that fMRI is a sensitive method to assess functional integrity of the brain. Activation maps allow to quantitatively assess the functionally compromized territory at an early stage following the ischemic event prior to the manifestation of pathomorphological changes.

Symptomatic characteristics of parkinsonism and the width of substantia nigra pars compacta on MRI according to ischemic changes in the putamen and cerebral white matter: implications for the diagnosis of vascular parkinsonism

To investigate the significance of vascular lesions as a cause of secondary parkinsonism, we analyzed the symptomatic characteristics, the width of the substantia nigra pars compacta (SNpc) on MRI and the responsiveness to L-dopa in 227 parkinsonian cases, excluding those with drug-induced parkinsonism and neurodegenerative diseases other than idiopathic Parkinson's disease (IPD). They were classified into those without a significant infarct in the basal ganglia (n = 144), those with status lacunaris in the putamen (SLP; n = 66) and those with confluent white matter hyperintensity signals (CWMH; n = 17). The 4- to 6-Hz tremor and cogwheel rigidity were significantly more frequent in cases without significant infarct (69%) than those with SLP (50%) and those with CWMH (12%; p < 0.05). Among cases with 4- to 6-Hz tremor and cogwheel rigidity, the frequency of patients with a reduced SNpc width and L-dopa responders did not significantly differ between those with SLP (73 and 83%, respectively) and those without significant infarct (83 and 86%, respectively), suggesting that the diagnosis for most of these cases would be probable IPD. In contrast, among cases without 4- to 6-Hz tremor and cogwheel rigidity, those with a reduced SNpc width or L-dopa responders were significantly less frequent among cases with SLP (25 and 38%, respectively) than among those without significant infarct (75 and 71%, respectively; p < 0.05). Patients with neither 4- to 6-Hz tremor and cogwheel rigidity nor reduction in the SNpc width, for whom the probable diagnosis was vascular parkinsonism (VP), were significantly more frequent in cases with SLP (26%) and with CWMH (40%) than those without significant infarct (8%), accounting for 10.6% of the total parkinsonian cases. These findings suggest that parkinsonian cases with SLP or CWMH consist of not only cases with vascular-lesion-related VP but also IPD in which vascular lesions are not directly related to parkinsonism. Absence of 4- to 6-Hz tremor, cogwheel rigidity and the reduction in the SNpc width could be indicators for differentiating VP from IPD.

Effects of anesthesia on functional activation of cerebral blood flow and metabolism

Functional brain mapping based on changes in local cerebral blood flow (lCBF) or glucose utilization (lCMR(glc)) induced by functional activation is generally carried out in animals under anesthesia, usually alpha-chloralose because of its lesser effects on cardiovascular, respiratory, and reflex functions. Results of studies on the role of nitric oxide (NO) in the mechanism of functional activation of lCBF have differed in unanesthetized and anesthetized animals. NO synthase inhibition markedly attenuates or eliminates the lCBF responses in anesthetized animals but not in unanesthetized animals. The present study examines in conscious rats and rats anesthetized with alpha-chloralose the effects of vibrissal stimulation on lCMR(glc) and lCBF in the whisker-to-barrel cortex pathway and on the effects of NO synthase inhibition with N(G)-nitro-L-arginine methyl ester (L-NAME) on the magnitude of the responses. Anesthesia markedly reduced the lCBF and lCMR(glc) responses in the ventral posteromedial thalamic nucleus and barrel cortex but not in the spinal and principal trigeminal nuclei. L-NAME did not alter the lCBF responses in any of the structures of the pathway in the unanesthetized rats and also not in the trigeminal nuclei of the anesthetized rats. In the thalamus and sensory cortex of the anesthetized rats, where the lCBF responses to stimulation had already been drastically diminished by the anesthesia, L-NAME treatment resulted in loss of statistically significant activation of lCBF by vibrissal stimulation. These results indicate that NO does not mediate functional activation of lCBF under physiological conditions.

Putaminal hyperperfusion in dystonic posturing on subtracted SPECT: a case report

Dystonic posturing (DP) is one of the most reliable lateralizing symptoms for mesial temporal lobe epilepsy, although the mechanism remains unclear. We demonstrated a hyperperfusion area in the right putamen on subtracted postictal SPECT by using the automatic registration technique in one patient with ictal DP of the left hand. The putamen may play a key role in DP, similar to other diseases with dystonia.

Facial myokymia in brain death

BACKGROUND

Brain death (BD) is the irreversible loss of all functions of the brain and brainstem. Spontaneous and reflex movements of the limbs have been described in this condition. However, facial myokymia (FM) in BD has not been previously reported. The origin of that motor phenomenon in alive patients is still uncertain, since supranuclear, nuclear and peripheral mechanisms have been proposed.

OBJECTIVE

We describe the presence of FM in a patient who fulfilled the criteria for BD. A 40-year-old-man had right-sided weakness and impaired consciousness. After 14 h admission, he fulfilled the criteria for BD. A CT scan of the head showed a large putaminal hemorrhage. The EEG was isoelectric. At that time, fine spontaneous twitches of the left cheek were noticed. They consisted of repetitive and rhythmic movements in groups of 3-5 lasting for < 5 s. These movements appeared every 2-10 min during 6 h.

DISCUSSION

Spinal reflexes have been described in BD. The presence of any movements other than the recognized reflexes may question this diagnosis and limit organ procurement for transplantation. The recognition of FM as an accepted movement in BD patients has practical and legal implications.

Dopa-induced blood flow responses in nonhuman primates

Initially, treatment with the dopamine precursor levodopa provides substantial symptomatic relief for patients with Parkinson's disease (PD). However, as the disease progresses, side effects such as involuntary movements or psychosis may accompany the response to medication. The mechanisms underlying these actions of levodopa remain unclear. To develop methodology for longitudinal studies of the effects of PD and levodopa treatment in living nonhuman primates, we first studied the effects of an acute dose of levodopa on regional brain activity in sedated baboons using positron emission tomography. We found that levodopa significantly decreased regional cerebral blood flow (rCBF) bilaterally in putamen and right cingulate and increased rCBF in right lateral temporal cortex and bilateral frontal cortex. We then performed similar studies on a nemestrina in awake and sedated states to determine whether these responses were affected by sedation. Interestingly, the directions of the rCBF responses in the putamen and temporal cortex were reversed depending on the presence or absence of sedation. Specifically, responses were decreased in sedated animals, but increased dose-dependently in the awake nemestrina. These findings have important implications for the interpretation of studies that use anesthesia. The responses in the awake nemestrina were most similar to those reported in humans and thus may be the most useful model system. Future imaging studies using selective dopaminergic agents in awake animals may permit the identification of relatively specific agonist-mediated pathways and may help separate the mechanisms that mediate levodopa's benefit from those that produce its unwanted side effects.

Arteries of the insula

OBJECT

The insula is located at the base of the sylvian fissure and is a potential site for pathological processes such as tumors and vascular malformations. Knowledge of insular anatomy and vascularization is essential to perform accurate microsurgical procedures in this region.

METHODS

Arterial vascularization of the insula was studied in 20 human cadaver brains (40 hemispheres). The cerebral arteries were perfused with red latex to enhance their visibility, and they were dissected with the aid of an operating microscope. Arteries supplying the insula numbered an average of 96 (range 77-112). Their mean diameter measured 0.23 mm (range 0.1-0.8 mm), and the origin of each artery could be traced to the middle cerebral artery (MCA), predominantly the M2 segment. In 22 hemispheres (55%), one to six insular arteries arose from the M1 segment of the MCA and supplied the region of the limen insulae. In an additional 10 hemispheres (25%), one or two insular arteries arose from the M3 segment of the MCA and supplied the region of either the superior or inferior periinsular sulcus. The insular arteries primarily supply the insular cortex, extreme capsule, and, occasionally, the claustrum and external capsule, but not the putamen, globus pallidus, or internal capsule, which are vascularized by the lateral lenticulostriate arteries (LLAs). However, an average of 9.9 (range four-14) insular arteries in each hemisphere, mostly in the posterior insular region, were similar to perforating arteries and some of these supplied the corona radiata. Larger, more prominent insular arteries (insuloopercular arteries) were also observed (an average of 3.5 per hemisphere, range one-seven). These coursed across the surface of the insula and then looped laterally, extending branches to the medial surfaces of the opercula.

CONCLUSIONS

Complete comprehension of the intricate vascularization patterns associated with the insula, as well as proficiency in insular anatomy, are prerequisites to accomplishing appropriate surgical planning and, ultimately, to completing successful exploration and removal of pathological lesions in this region.

[Clinical study of cerebral blood flow in unilateral chronic subdural hematoma measured by 99mTc-HMPAO SPECT]

Cerebral blood flow (CBF) measured by 99mTc-HMPAO SPECT before operation was studied in 60 patients with unilateral chronic subdural hematoma. The regional CBF was measured in 26 regions of the fronto-occipital 10 cortices, putamen, thalamus and cerebellar hemisphere on both sides. Sixty cases with unilateral chronic subdural hematoma were classified into four groups on the basis of clinical symptoms: 17 cases with headache (headache group), 34 cases with hemiparesis (hemiparesis group) and 9 cases with consciousness disturbance or dementia (consciousness disturbance group), and into three groups on the basis of the degree of midline brain shift on MRI: 7 cases of mild shift group, 24 cases of moderate shift group and 29 cases of severe shift group. The average CBF in 60 patients in each region indicated that the regional CBF was reduced in frontal, occipital cortices and cerebellum on the non-hematoma side, and in putamen and thalamus on the hematoma side. In the headache group, the regional CBF reduction on the non-hematoma side was found in only frontal and occipital cortices compared with the corresponding regions on the hematoma side. In the hemiparesis group, the regional CBF was reduced in frontal and occipital cortices on the non-hematoma side and in putamen and thalamus on the hematoma side. The part of CBF reduction in both hemispheres was also noted in the hemiparesis group. In the consciousness disturbance group, the CBF reduction was markedly noted in whole brain. The CBF reductions in frontal and occipital cortices on the non-hematoma side and in putamen, thalamus and cerebellum on the hematoma side was not mutually related with the degree of midline brain shift. We concluded that the disturbance of CBF in chronic subdural hematoma was started from frontal and occipital cortices on the non-hematoma side observed in the headache group, and which was extended to putamen and thalamus on the hematoma side and a part of both hemispheres observed in the hemiparesis group. And such disturbance was finally observed as the CBF reductions in whole brain in the consciousness disturbance group.

Increased blood flow in the basal ganglia when using cues to direct attention

We used positron emission tomography (PET) in ten subjects to study the brain regions involved in voluntary shifts of attention. For six scans, subjects performed a visual target detection task in which the location of the target was indicated in advance on some proportion of trials by the appearance of an arrow cue at fixation. The informative cues were successful in speeding reaction time to the target. Blood flow in the left putamen was correlated with the proportion of informative cues provided within a scan. We discuss this finding in terms of three possible interpretations: attentional shifts, response inhibition, and motor preparation related to the use of the right hand to respond. Blood flow in cortical regions commonly associated with attention was not related to cue ratio, a finding that may reflect automatization of the processes involved in interpreting and using the cues.

Xenon contrast-enhanced CT imaging of supratentorial hypoperfusion in patients with brain stem infarction

BACKGROUND AND PURPOSE

The characteristics of hypoperfusion in the supratentorial region of patients with brain stem infarction are unclear. We investigated the relationships between the presence of hypoperfusion and the location, number, and size of the infarcts with xenon contrast-enhanced CT.

METHODS

One hundred five patients with brain stem infarction detected by MR imaging underwent xenon contrast-enhanced CT to measure the regional CBF (rCBF) in the frontal, temporal, parietal, and occipital regions and in the putamen and thalamus. A decrease of more than 10% from the mean rCBF value for normal individuals was considered to indicate hypoperfusion.

RESULTS

Thirty-six patients had supratentorial hypoperfusion. The mean rCBF values (measured in mL/100 g/minute) were as follows: frontal region, 36.2 +/- 5.1 (-14.8%, n = 28); parietal region, 42.3 +/- 4.7 (-19.1%, n = 29); temporal region, 41.5 +/- 2.8 (-12.6%, n = 12); and thalamus, 50.1 +/- 3.2 (-19.6%, n = 7). Supratentorial hypoperfusion was associated with pontine infarction in 33 patients (upper pons in 15, middle pons in 18, and lower pons in seven), midbrain infarction in two, and medulla infarction in one. Twenty-three patients had infarcts that were larger than 5 mm, and 11 had infarcts that were 2 to 5 mm. Only two had infarcts that were smaller than 2 mm. Seven patients each had one infarct, 13 each had two, and 16 each had three.

CONCLUSION

Supratentorial hypoperfusion was associated with larger infarcts, with more infarcts, and with pontine infarction.

Lenticulocapsular hemorrhages presenting as pure sensory stroke

Pure sensory stroke (PSS) syndrome is most often produced by a small infarct involving the lateral thalamus. Larger than lacune-sized putaminal hemorrhages have not been considered as a cause of this syndrome. The author describes 3 patients with hypertensive lenticulocapsular hemorrhage presenting with hemisensory symptoms without any other neurological deficits. In these patients, the sensory symptoms were more marked and persistent in the legs than in the other body parts. Neuroradiological data suggested that thalamocortical sensory pathways were exclusively involved. These patients highlight the heterogeneity of the vascular lesion producing PSS syndrome and illustrate that a putaminal hemorrhage should be included in the differential diagnosis of this clinical syndrome.

Unusual CT and MRI appearance of carbon monoxide poisoning

Unilateral low attenuation areas within the right putamen, globus pallidus and thalamus were observed on CT in a patient after exposure to carbon monoxide. A transient bilateral appearance was found on subsequent CT examinations. Hemorrhagic infarction of the right putamen, and ischemic lesions in both thalami were visualized on MRI 2 weeks later.

Developmental characteristics of vessel density in the human fetal and infant brains

We demonstrated the developmental characteristics of vessel density in the human brain, using an antibody against CD31, which specifically reacts with endothelium. In the cerebral cortex and subcortical white matter, the vessel density was low at 16-28 weeks of gestation (GW), and then increased after 36 GW. In the deep white matter, the vessel density was high in the middle fetal period (16-24 GW), and then transiently decreased at 28-36 GW, and increasing after 39 GW. In the putamen, the vessel density was high at 20-21 GW, remained high throughout the fetal period, and then rapidly increased after birth. In the basis pontis, the number of vessels increased after 28 GW, and after 32 GW was greater than in the pontine tegmentum. These alterations in vessel density may correlate with the pathogenesis of perinatal brain injury. Thus, the transient decrease of vessel density in the deep white matter may predispose to periventricular leukomalacia in cerebral hypoperfusion. Similarly, the well-developed vascularity in the basis pontis may predispose its relatively immature neurons to neuron necrosis produced by free radical injury.

Correlation between contingent negative variation and regional cerebral blood flow

The relationship between contingent negative variation (CNV) and regional cerebral blood flow was investigated, using the stable xenon computed tomography method. Seventeen cases of chronic multiple cerebral infarction in the perforating artery areas (vascular dementia, mean age 67.0), 6 cases of Alzheimer's disease (mean age 69.5) and 8 healthy controls (mean age 62.5) were studied. Regional cerebral blood flows in the frontal, temporal, parietal and occipital cortex, frontal, temporal and occipital white matter, caudate nucleus, putamen and thalamus were measured. The amplitude of early CNV was significantly smaller in the vascular dementia group than in the healthy control group. The blood flows in the parietal cortex and thalamus were significantly lower in the vascular dementia group than in the healthy control group. There was a significant positive correlation between the amplitude of early CNV and frontal cortex blood flow. No significant correlations were present between the CNV and the other regional cerebral blood flows nor in healthy controls. The amplitude of CNV has been reported to be decreased in dementia. From the present study, the amplitude of early CNV was considered to be influenced by the blood flow in the frontal cortex.

Subcortical crossed aphasia

A 55 year-old, right-handed, hypertensive woman with global aphasia, due to a spontaneous hemorrhage in the right putamen extending to the periventricular white matter was examined thirteen days after the acute onset of stroke. She had left hemiplegia and inability to speak. She displayed no spontaneous speech output and was capable only of occasional undifferentiated grunts in conversation. Other language modalities such as auditory and reading comprehension, naming, repetition and writing were severely impaired. Her aphasia was classified as global aphasia. Forty-five days after the onset of stroke, rapid recovery from the aphasia with mild deficits in speaking, naming, and repetition was detected. This case is a good example of crossed aphasia, favouring the importance of deep structures of the right hemisphere in this type of aphasia. Rapid recovery is an important feature.

Multivariate analysis of predictors of hematoma enlargement in spontaneous intracerebral hemorrhage

BACKGROUND AND PURPOSE

We conducted this study to determine, through use of multivariate analyses, the independent predictors of hematoma enlargement occurring after hospital admission in patients with spontaneous intracerebral hemorrhage (i.c.h.).

METHODS

We reviewed 627 patients with ICH admitted within 24 hours of onset. The first CT was performed at admission and the second within 24 hours of admission, and a blood sample was taken for laboratory examinations. Univariate and multivariate analyses were performed to assess the relationships between hematoma enlargement and time from onset, consciousness level, CT findings, amount of alcohol consumption, systolic blood pressure at and after admission, clinical outcome, and hematologic parameters.

RESULTS

Eighty-eight patients (14.0%) showed enlarged hematomas after admission. Multivariate analyses revealed that the following five factors were independently associated with hematoma enlargement: the time from onset (odds ratio [OR], 0.26 for a 1-SD change; 4.9 hours; P < 0.001); the amount of alcohol consumption (OR, 1.50 for 1 SD; 46.3 g/d; P = 0.002); the sharp of hematoma (OR, 1.40 for 1 SD; 0.45 round; P = 0.006); the presence of consciousness disturbance (OR, 1.38 for 1 SD; 0.50 coma; P = 0.026); and the level of fibrinogen (OR, 0.74 for 1 SD; 87.1 mg/dL; P = 0.042). Hematoma enlargement was an independent factor increasing the mortality rate in the ICH patients (OR, 1.57; P < 0.001).

CONCLUSIONS

A particularly high likelihood of hematoma enlargement was observed in patients who (in order of importance) were admitted shortly after onset, who were heavy drinkers; who had an irregularly shaped hematoma, whose consciousness was disturbed, and who had a low level of fibrinogen.