Cerebral Subcortical White Matter Research Articles

Fahr's syndrome with hypoparathyroidism, thrombocytopenia, and seizure: a rare case report.

A 32-year-old male was brought with a repeated history of twitching of hands, tingling sensation, and uncontrolled seizure despite medications. Computed tomography findings showed bilateral basal ganglia, cerebellar dentate nuclei, and subcortical cerebral white matter calcifications. Laboratory studies revealed reduced levels of calcium, parathyroid hormone, and thrombocyte count. Based on these investigations Fahr's syndrome probably due to hypoparathyroidism with thrombocytopenia was diagnosed. The patient was initially treated with intravenous calcium gluconate and platelet transfusion followed by oral calcium supplementation. Fahr's syndrome due to hypoparathyroidism should be suspected in any patient with neurological symptoms and hypocalcemia. Seizures in the patient of Fahr's syndrome with thrombocytopenia could be very detrimental due to the risk of intracranial hemorrhage. Hence, treatment should be started as early as possible.

Differential reductions in the capillary red-blood-cell flux between retina and brain under chronic global hypoperfusion.

It has been hypothesized that abnormal microcirculation in the retina might predict the risk of ischemic damages in the brain. Direct comparison between the retinal and the cerebral microcirculation using similar animal preparation and under similar experimental conditions would help test this hypothesis. We investigated capillary red-blood-cell (RBC) flux changes under controlled conditions and bilateral-carotid-artery-stenosis (BCAS)-induced hypoperfusion, and then compared them with our previous measurements performed in the brain. We measured capillary RBC flux in mouse retina with two-photon microscopy using a fluorescence-labeled RBC-passage approach. Key physiological parameters were monitored during experiments to ensure stable physiology. We found that under the controlled conditions, capillary RBC flux in the retina was much higher than in the brain (i.e., cerebral cortical gray matter and subcortical white matter), and that BCAS induced a much larger decrease in capillary RBC flux in the retina than in the brain. We demonstrated a two-photon microscopy-based technique to efficiently measure capillary RBC flux in the retina. Since cerebral subcortical white matter often exhibits early pathological developments due to global hypoperfusion, our results suggest that retinal microcirculation may be utilized as an early marker of brain diseases involving global hypoperfusion.

Neurologic involvement in seronegative primary Sjögren's syndrome with positive minor salivary gland biopsy: a single-center experience.

To assess the demographics, neurologic manifestations, comorbidities, and treatment of patients with seronegative primary Sjögren's syndrome (pSS). We conducted a retrospective chart review on patients with seronegative pSS evaluated by a neurologist at the University of Utah Health between January 2010 and October 2018. The diagnosis was based on characteristic symptoms, positive minor salivary gland biopsy according to the American-European Consensus Group 2002 criteria, and seronegative antibody status. Of 45 patients who met the study criteria, 42 (93.3%) were Caucasian, and 38 (84.4%) were female. The patients' mean age at diagnosis was 47.8 ± 12.6 (range 13-71) years. Paresthesia, numbness and dizziness, and headache were noted in 40 (88.9%), 39 (86.7%), and 36 patients (80.0%), respectively. Thirty-four patients underwent brain magnetic resonance imaging. Of these, 18 (52.9%) showed scattered nonspecific periventricular and subcortical cerebral white matter T2/fluid-attenuated inversion recovery hyperintense foci. Twenty-nine patients (64.4%) presented to the neurology clinic prior to pSS diagnosis, and the median delay in diagnosis from the first neurology clinic visit was 5 (interquartile ranges 2.0-20.5) months. Migraine and depression were the most common comorbidities in 31 patients (68.9%). Thirty-six patients received at least one immunotherapy, and 39 were on at least one medication for neuropathic pain. Patients often display various nonspecific neurological symptoms. Clinicians should express a high degree of skepticism regarding seronegative pSS and consider minor salivary gland biopsy to avoid delaying diagnosis, as undertreatment can affect patients' quality of life.

Measurements of cerebral microvascular blood flow, oxygenation, and morphology in a mouse model of whole-brain irradiation-induced cognitive impairment by two-photon microscopy and optical coherence tomography: evidence for microvascular injury in the cerebral white matter.

Whole-brain irradiation (WBI, also known as whole-brain radiation therapy) is a mainstay treatment modality for patients with multiple brain metastases. It is also used as a prophylactic treatment for microscopic tumors that cannot be detected by magnetic resonance imaging. WBI induces a progressive cognitive decline in ~ 50% of the patients surviving over 6months, significantly compromising the quality of life. There is increasing preclinical evidence that radiation-induced injury to the cerebral microvasculature and accelerated neurovascular senescence plays a central role in this side effect of WBI. To better understand this side effect, male C57BL/6 mice were first subjected to a clinically relevant protocol of fractionated WBI (5Gy, two doses per week, for 4weeks). Nine months post the WBI treatment, we applied two-photon microscopy and Doppler optical coherence tomography to measure capillary red-blood-cell (RBC) flux, capillary morphology, and microvascular oxygen partial pressure (PO2) in the cerebral somatosensory cortex in the awake, head-restrained, WPI-treated mice and their age-matched controls, through a cover-glass-sealed chronic cranial window. Thanks to the extended penetration depth with the fluorophore - Alexa680, measurements of capillary blood flow properties (e.g., RBC flux, speed, and linear density) in the cerebral subcortical white matter were enabled. We found that the WBI-treated mice exhibited a significantly decreased capillary RBC flux in the white matter. WBI also caused a significant reduction in capillary diameter, as well as a large (although insignificant) reduction in segment density at the deeper cortical layers (e.g., 600-700μm), while the other morphological properties (e.g., segment length and tortuosity) were not obviously affected. In addition, we found that PO2 measured in the arterioles and venules, as well as the calculated oxygen saturation and oxygen extraction fraction, were not obviously affected by WBI. Lastly, WBI was associated with a significant increase in the erythrocyte-associated transients of PO2, while the changes of other cerebral capillary PO2 properties (e.g., capillary mean-PO2, RBC-PO2, and InterRBC-PO2) were not significant. Collectively, our findings support the notion that WBI results in persistent cerebral white matter microvascular impairment, which likely contributes to the WBI-induced brain injury and cognitive decline. Further studies are warranted to assess the WBI-induced changes in brain tissue oxygenation and malfunction of the white matter microvasculature as well.

Imaging Patterns Characterizing Mitochondrial Leukodystrophies.

Achieving a specific diagnosis in leukodystrophies is often difficult due to clinical and genetic heterogeneity. Mitochondrial defects cause 5%-10% of leukodystrophies. Our objective was to define MR imaging features commonly shared by mitochondrial leukodystrophies and to distinguish MR imaging patterns related to specific genetic defects. One hundred thirty-two patients with a mitochondrial leukodystrophy with known genetic defects were identified in the data base of the Amsterdam Leukodystrophy Center. Numerous anatomic structures were systematically assessed on brain MR imaging. Additionally, lesion characteristics were scored. Statistical group analysis was performed for 57 MR imaging features by hierarchic testing on clustered genetic subgroups. MR imaging features indicative of mitochondrial disease that were frequently found included white matter rarefaction (n = 50 patients), well-delineated cysts (n = 20 patients), T2 hyperintensity of the middle blade of the corpus callosum (n = 85 patients), and symmetric abnormalities in deep gray matter structures (n = 42 patients). Several disorders or clusters of disorders had characteristic features. The combination of T2 hyperintensity in the brain stem, middle cerebellar peduncles, and thalami was associated with complex 2 deficiency. Predominantly periventricular localization of T2 hyperintensities and cystic lesions with a distinct border was associated with defects in complexes 3 and 4. T2-hyperintense signal of the cerebellar cortex was specifically associated with variants in the gene NUBPL. T2 hyperintensities predominantly affecting the directly subcortical cerebral white matter, globus pallidus, and substantia nigra were associated with Kearns-Sayre syndrome. In a large group of patients with a mitochondrial leukodystrophy, general MR imaging features suggestive of mitochondrial disease were found. Additionally, we identified several MR imaging patterns correlating with specific genotypes. Recognition of these patterns facilitates the diagnosis in future patients.

Cortical myoclonus and epilepsy in a family with a new SLC20A2 mutation

Idiopathic basal ganglia calcification (IBGC) or primary familial brain calcification is a rare genetic condition characterized by an autosomal dominant inheritance pattern and the presence of bilateral calcifications in the basal ganglia, thalami, cerebellum and cerebral subcortical white matter. The syndrome is genetically and phenotypically heterogeneous. Causal mutations have been identified in four genes: SLC20A2, PDGFRB, PDGFB and XPR1. A variety of progressive neurological and psychiatric symptoms have been described, including cognitive impairment, movement disorders, bipolar disorder, chronic headaches and migraine, and epilepsy. Here we describe a family with a novel SLC20A2 mutation mainly presenting with neurological symptoms including cortical myoclonus and epilepsy. While epilepsy, although rare, has been reported in patients with IBGC associated with SLC20A2 mutations, cortical myoclonus seems to be a new manifestation.

1766. Osimertinib-Associated Progressive Multifocal Leucoencephalopathy

BackgroundProgressive multifocal leukoencephalopathy (PML) is a rare demyelinating disease of white matter in the central nervous system (CNS) caused by reactivation of John Cunningham (JC) virus. Drug-induced PML is increasingly reported with the widely used biological immunosuppressant drugs and molecular targeted antineoplastic agents. Monoclonal antibodies were the pioneer drugs to be associated with PML including the prototypical natalizumab.MethodsEpidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKI) have been rarely described in this context with few case reports of ibrutinib-associated PML. Osimertinib, a third-generation EGFR TKI, was recently FDA-approved for the first-line treatment of metastatic non-small-cell lung cancer (NSCLC), and to the best of our knowledge has never been associated with PML. We describe a case report of a rapidly progressive PML likely associated with osimertinib therapy.ResultsA 85-year-old female with history of NSCLC, on osimertinib, was admitted with progressively worsening left hemiparesis, facial palsy, unsteady gait, recurrent falls, and episodic confusion over a period of month. Brain magnetic resonance imaging revealed foci of non-enhancing increased T2 and fluid-attenuated inversion recovery (FLAIR) signal intensity in the periventricular and bilateral cerebral subcortical white matter. MRI cervical spine was unremarkable for acute enhancing lesions. Cerebrospinal fluid (CSF) was unremarkable for infectious etiology, oligoclonal bands, and cytology. The patient was readmitted 2 weeks later with worsening neurological deficits and new lesions in the bilateral middle cerebellar peduncles, pons, midbrain, and cerebral white matter. Positive CSF JC virus PCR lead to the final diagnosis of “probable” PML. Biopsy was deferred for high clinical suspicion of PML and procedural risks outweighing benefits. Osimertinib was likely contributing to PML in the absence of other immunosuppression.ConclusionInhibition of tyrosine kinase-dependent pathways can potentially aid in the replication of JC virus per previously reported ibrutinib-associated PML. Clinicians should be aware of PML risk in patients on osimertinib and TKI therapy, especially those with positive serum JC virus serology. Disclosures All authors: No reported disclosures.

Neuropathology of Spontaneous Hypertensive Encephalopathy in Cats.

Pathologic features of 12 cats with naturally acquired systemic hypertension and concomitant hypertensive encephalopathy were analyzed. All cats demonstrated acute onset of signs localized to the forebrain and/or brainstem, including stupor, coma, and seizures. All cats had systemic hypertension, ranging from 160 to 300 mm Hg. Gross lesions were identified in 4 of 12 cases, including caudal herniation of the cerebrum and cerebellum, sometimes with compression of the rostral colliculus and medulla. Histologically, all cases featured bilaterally symmetrical edema of the cerebral white matter. Associated vascular lesions, especially arteriolar hyalinosis, were also observed. Concurrent lesions were chronic tubulointerstitial nephritis (11/12 cases), adenomatous hyperplasia of the thyroid gland (4 cases), hypertensive choroidal arteriopathy (6 cases), and left ventricular hypertrophy (5 cases). This study demonstrates that the typical histologic manifestation of spontaneous hypertensive encephalopathy in cats is bilaterally symmetrical edema of the subcortical cerebral white matter.

Follow-up of folinic acid supplementation for patients with cerebral folate deficiency and Kearns-Sayre syndrome.

BackgroundKearns-Sayre syndrome (KSS) is a mitochondrial DNA deletion syndrome that presents with profound cerebral folate deficiency and other features. Preliminary data support the notion that folinic acid therapy might be useful in the treatment of KSS patients. Our aim was to assess the clinical and neuroimaging outcomes of KSS patients receiving folinic acid therapy.MethodsPatients: We recruited eight patients with diagnoses of KSS. Four cases were treated at 12 de Octubre Hospital, and the other two cases were treated at Sant Joan de Déu Hospital. Two patients refused to participate in the treatment protocol.Methods: Clinical, biochemical and neuroimaging data (magnetic resonance imaging or computed tomography scan) were collected in baseline conditions and at different time points after the initiation of therapy. Cerebrospinal fluid 5-methyltetrahydrofolate levels were analysed with HPLC and fluorescence detection. Large-scale mitochondrial DNA deletions were analysed by Southern blot.Treatment protocol: The follow-up periods ranged from one to eight years. Cases 1–4 received oral folinic acid at a dose of 1 mg/kg/day, and cases 6 and 8 received 3 mg/kg/day.ResultsNo adverse effects of folinic acid treatment were observed. Cerebral 5-methyltetrahydrofolate deficiencies were observed in all cases in the baseline conditions. Moreover, all three patients who accepted lumbar puncture after folinic acid therapy exhibited complete recoveries of their decreased basal cerebrospinal fluid 5-methyltetrahydrofolate levels to normal values. Two cases neurologically improved after folinic therapy. Disease worsened in the other patients.Post-treatment neuroimaging was performed for the 6 cases that received folinic acid therapy. One patient exhibited improvements in white matter abnormalities. The remaining patients displayed progressions in subcortical cerebral white matter, the cerebellum and cerebral atrophy.ConclusionsFour patients exhibited clinical and radiological progression of the disease following folinic acid treatment. Only one patient who was treated in an early stage of the disease exhibited both neurological and radiological improvements following elevated doses of folinic acid, and an additional patient experienced neurological improvement. Early treatment with high-dose folinic acid therapy seems to be advisable for the treatment of KSS.Trial registrationEudracT2007-00-6748-23Electronic supplementary materialThe online version of this article (doi:10.1186/s13023-014-0217-2) contains supplementary material, which is available to authorized users.

Neurocognitive Impairment in Adults With Moyamoya Disease Without Stroke

Adults with moyamoya disease (MMD) have been shown to manifest cognitive impairment, but it is unclear whether this is the result of ischemic stroke. To determine whether adults with MMD but without stroke have cognitive impairment. We performed detailed neuropsychological assessments in 30 adults with angiographically confirmed MMD without magnetic resonance imaging (MRI) evidence of stroke. Twenty patients (67%) exhibited small T2 hyperintensities in the cerebral subcortical white matter on brain MRI but no evidence of gray matter damage. Significant cognitive impairment, defined as half of test scores ≥ 1 SD below the normal mean, was present in 7 patients (23%). Executive functioning, mental efficiency, and word finding were the ability areas most frequently impaired, whereas memory was relatively intact. Clinically significant emotional distress (depression and/or anxiety) was present in 11 patients (37%). Comparable cognitive findings were also observed in the subset of 10 patients (33%) with completely normal static brain MRI. Cognitive impairment in MMD can occur in the absence of ischemic stroke as manifested on MRI.

Movement disorders: role of imaging in diagnosis

Magnetic resonance imaging (MRI and single-photon emission computed tomography (SPECT) have a considerable role in the diagnosis of the single patient with movement disorders. Conventional MRI demonstrates symptomatic causes of parkinsonism but does not show any specific finding in Parkinson's disease (PD). However, SPECT using tracers of the dopamine transporter (DAT) demonstrates an asymmetric decrease of the uptake in the putamen and caudate from the earliest clinical stages. In other degenerative forms of parkinsonism, including progressive supranuclear palsy (PSP), multisystem atrophy (MSA), and corticobasal degeneration (CBD), MRI reveals characteristic patterns of regional atrophy combined with signal changes or microstructural changes in the basal ganglia, pons, middle and superior cerebellar peduncles, and cerebral subcortical white matter. SPECT demonstrates a decreased uptake of tracers of the dopamine D2 receptors in the striata of patients with PSP and MSA, which is not observed in early PD. MRI also significantly contributes to the diagnosis of some inherited hyperkinetic conditions including neurodegeneration with brain iron accumulation and fragile-X tremor/ataxia syndrome by revealing characteristic symmetric signal changes in the basal ganglia and middle cerebellar peduncles, respectively. A combination of the clinical features with MRI and SPECT is recommended for optimization of the diagnostic algorithm in movement disorders.

Atypical Metronidazole-Induced Encephalopathy in Anaerobic Brain Abscess

Metronidazole-induced encephalopathy is a very rare complication of the long standing use of metronidazole. The encephalopathy is bilateral and symmetric in nature. We report on the magnetic resonance imaging (MRI) and clinical course of metronidazole-induced encephalopathy in a 60-year-old female with a persistent anaerobic brain abscess after draining of the abscess. After 3 months of metronidazole administration, the patient complained of dysarthria, tingling sense of all extremities, and left hemiparesis. MRI revealed symmetric hyperintensity lesions in medulla, pons, dentate nuclei of cerebellum, and splenium of corpus callosum, all of which represent typical findings of metronidazole-induced encephalopathy. In addition, asymmetric lesions in midbrain, thalamus, putamen and cerebral subcortical white matter were noted. The patient recovered after discontinuation of metronidazole and the remaining abscess was successfully treated with meropenem and levofloxacine.

Lesões perinatais em cordeiros induzidas pela administração de Tetrapterys multiglandulosa (Malpighiaceae) a ovelhas em diferentes estágios de gestação

Foi realizada a intoxicação experimental em ovelhas em diferentes dias de gestação, 12 ovelhas foram dividas em quatro grupos. As ovelhas do Grupo 1 consumiram quatro doses de 5g/kg de folhas verdes durante quatro dias; ovinos do Grupo 2 consumiram duas doses de 10g/kg durante dois dias, o Grupo 3 consumiu uma dose de 20g/kg em um único dia e os ovinos do Grupo 4 não consumiram a planta (controle-negativo). Para testar a toxicidade da planta um ovino macho consumiu 5g/kg até manifestação dos sintomas. Não foram observados sinais clínicos da intoxicação nas ovelhas, mas três cordeiros tiveram morte perinatal, e um cordeiro morreu com três meses de idade; o ovino controle-positivo morreu após 38 dias de consumo diário da planta e os sinais clínicos foram taquipnéia, taquicardia, sonolência, incoordenação e fraqueza. Todos os quatro cordeiros e o ovino controle-positivo foram necropsiados e os achados de necropsia foram áreas esbranquiçadas no miocárdio, evidenciação do padrão lobular do fígado, pulmão vermelho enegrecido e rúmen acentuadamente distendido com presença de gases livres. Os achados histopatológicos foram fibrose cardíaca, necrose dos cardiomiócitos, congestão e edema pulmonar, congestão hepática centrolobular e degeneração esponjosa na região subcortical do encéfalo. Tetrapterys multiglandulosa demonstrou ser tóxica para os fetos ovinos em dosagens que não foram suficientes para induzir sinais clínicos nas ovelhas prenhes, e que a intoxicação pode ocorrer com morte de cordeiros logo após o parto, mesmo após meses de ter cessada a ingestão da planta.

Osteoma of the calvaria in l‐2‐hydroxyglutaric aciduria

L-2-Hydroxyglutaric aciduria (L-2-OHGA) is a rare autosomal recessive neurometabolic disease linked to chromosome 14q21.1 and is caused by mutations in the gene that most likely encodes L: -2-hydroxyglutarate dehydrogenase, which normally catalyses L: -2-hydroxyglutarate to alpha-ketoglutarate. It is characterized by progressive mental deterioration, pyramidal and cerebellar syndromes, macrocephaly and marked polycystic white-matter degeneration mainly involving frontal lobes. Brain tumours of variable nature have frequently been observed in L-2-OHGA. We report a patient affected by this disease who at the age of 20 years developed a bone tumour involving the right frontal region of the calvaria. He had first presented at the age of 10 years with psychomotor delay, clumsy gait and moderate mental impairment. Examination showed macrocephaly, cerebellar ataxia and quadripyramidal syndrome. Brain MRI showed low signal intensities on T1-weighted images and high signal intensities on T2-weighted images in cerebral subcortical white matter. Serum and urinary amino acid assay was normal. Urinary 2-hydroxyglutaric acid was 1418 mmol/mol creatinine (controls <25). Analysis of the L-2-hydroxyglutarate dehydrogenase gene revealed a homozygous mutation in exon 2 (A320G). At the age of 20 years, an osteoma of the right frontal bone was diagnosed. This finding reinforces the opinion concerning the association of L-2-OHGA and tumorigenesis and prompted us to verify the possible responsibility of some overproduced substances in this disease for the development of tumours and to look for any correlation between the type of mutation in the L-2-OHGA gene and the tumorigenic potential observed in some patients affected by this disease.

The microvasculature of the cerebral white matter: arteries of the subcortical white matter.

The microvascular architecture of the human cerebral subcortical white matter was studied. Most of the subcortical arteries ran straight through the cortex, but upon entering the white matter, they began to coil, loop, and spiral. Vascular stains showed wide spaces between the adventitial sheaths and blood vessels. The blood vessels coiled, looped, and spiraled within these wide adventitial spaces. This phenomenon was observed in the brains from persons ranging from the first to ninth decades of life and there were no statistically significant age-related correlations. Furthermore, there was no evidence of a reduction in the volume of white matter after fixation. Therefore, the observed tortuosity does not appear to be the result of shrinkage of brain tissue following fixation. While the mechanisms responsible for the subcortical arteries circuitry remain undetermined, this coiling architecture may serve as a trap for tumor cells and microorganisms passing through the blood stream, suggesting that these coiling arterial blood vessels may play a significant role in the pathogenesis of tumor metastasis and the brain abscess that frequently occurs in the gray-white matter junction.

Acute disseminated encephalomyelitis associated with parainfluenza virus infection of childhood

Acute disseminated encephalomyelitis associated with the parainfluenza virus has rarely been reported in childhood. A 2.5-year-old girl with acute disseminated encephalomyelitis, who developed bilateral symmetrical lesions in the basal ganglion, thalamus, corpus callosum, cerebral subcortical white matter, and cerebellar medulla on brain magnetic resonance imaging is described. Serological confirmation of parainfluenza virus infection was made 2 weeks following the onset of neurological symptoms. Four months later, the patient had a full recovery. At present, 3 years later, no relapse has been reported and she is leading a normal life. Our case is of interest because of its rarity, the striking brain magnetic resonance imaging, and the good neurological outcome.

White matter changes: the clinical consequences in the aging population.

Neuroimaging changes in the cerebral subcortical white matter (WMC) are recognized with the highest frequency in elderly subjects, particularly in those with vascular risk factors. WMC have been consistently reported to be associated with global or selective cognitive deficits, depression, motor and gait impairment. All these deficits are main contributors to disability in the elderly. Moreover, subjects with WMC have an increased risk of cardiovascular events and death from vascular causes. Functional status in subjects with WMC is variable, from normal to severely (physically or cognitively) disable. The association of WMC with age and with some of the clinical manifestations of aging suggests that WMC could be one of the age-related processes involved in the transition to disability in the elderly. Large cohorts of patients with WMC of different severity and detailed follow-up observation may help elucidating this issue. If WMC are shown to have an impact on disability in the aged population, efforts could be made to prevent WMC and WMC-related motor and cognitive deficits, and to identify measures aimed to halt or slow their progression.

Circadian Variations of Blood Pressure in Patients With Sequelae of Carbon Monoxide Poisoning

It has been shown that carbon monoxide poisoning causes necrosis of the globus pallidum and the cerebral cortex, and a diffuse demyelination of the cerebral subcortical white matter, resulting in the impairment of the higher brain functions manifested as memory disturbances, apraxia, and agnosia. The purpose of the present study was to determine the effects of the lesions in the brain caused by carbon monoxide poisoning on the circadian changes in blood pressure and pulse rate. We measured the ambulatory blood pressure in 15 male patients with the sequelae of acute carbon monoxide poisoning and 16 age- and sex-matched controls. Using either brain computed tomography or brain magnetic resonance imaging, we determined that seven patients had lesions in the globus pallidum bilaterally, four had lesions in the parietotemporooccipital lobe bilaterally, and five had multiple deep white matter lesions. Circadian variations of blood pressure and pulse rate did not show any significant differences in either group. The average 24-h blood pressures were 120.8 +/- 2.2 (systolic)/74.1 +/- 1.5 mm Hg (diastolic) in the patients and 117.4 +/- 2.7/74.5 +/- 2.1 mm Hg in the controls. The daytime (6:00 to 21:00) and nighttime (21:00 to 6:00) blood pressures were 127.3 +/- 2.3/78.0 +/- 1.5 mm Hg and 109.7 +/- 2.4/67.4 +/- 1.7 mm Hg in the patients, and 121.6 +/- 2.9/77.5 +/- 2.2 mm Hg and 110.0 +/- 2.7/69.3 +/- 1.8 mm Hg in the controls, respectively. Furthermore, there were no differences in cardiovascular and plasma catecholamine responses induced by either a head-up tilt or a cold pressor test between the two groups. It is concluded that diffuse or multiple lesions in bilateral cerebral hemispheres caused by carbon monoxide poisoning per se do not affect the circadian changes in blood pressure and pulse rate observed in normotensive subjects.

Central nervous system lesions and cervical disc herniations in amateur divers

Permanent neuropsychological changes such as memory disturbances and depression have been found in professional divers, even in those who have never had decompression sickness. The changes are probably the result of intravascular gas bubbles insufficient to cause acute symptoms. We examined amateur divers with long histories of self-contained underwater breathing apparatus diving by magnetic resonance imaging and compared them with normal controls. Hyperintense lesions of the subcortical cerebral white matter and degenerative changes of the cervical disks were significantly more common in the divers. 27 of 52 divers had a total of 86 focal hyperintensities versus 10 of 50 controls with 14 focal hyperintensities (p<0·01). 32 divers had at least one degenerated intravertebral disc versus 9 controls (p<0·0001). These results suggest that amateur divers are at risk of accumulating lesions in the central nervous system and in cartilage.

Ubiquitinated structures in the white matter of the gerbil following chronic cerebral hypoperfusion.

Chronic cerebral hypoperfusion was produced in adult gerbils aged 3-6 months following bilateral stenosis of the carotid artery lasting 8 weeks. Animals with no evidence of cerebral infarction were used in the present study. Ubiquitin-immunoreactive free granules in the subcortical cerebral white matter and corpus callosum were observed in five of 12 animals. No similar lesions were found in sham-operated animals, age-matched controls, and gerbils subjected to transient forebrain ischaemia for 20 min and killed at different intervals. These results indicate that diffuse damage of the subcortical white matter may be encountered as the only neuropathological change following chronic hypoperfusion.