Ill-defined neurological syndromes with autoimmune background: a diagnostic challenge

OBJECTIVE

To define the diagnostic features of a cohort of patients presenting with autoimmune manifestations and atypical neurological features not fulfilling criteria for a well defined neurological or connective tissue disorder.

METHODS

Twenty-nine such patients were referred to our institution for evaluation. Nine were excluded from this study since they were diagnosed with antiphospholipid syndrome. The remaining 20 patients underwent complete clinical and laboratory evaluation, spinal fluid analysis, minor salivary gland biopsy (if sicca features were present), and were tested for evoked potentials. Magnetic resonance imaging (MRI) scans of the brain were performed in all patients and of the spine in 7.

RESULTS

Brain and/or spinal cord MRI abnormalities were found in all 20 patients. Based on morphologic criteria and distribution, these lesions were classified into 3 subsets: (1) multiple sclerosis (MS)-like (4 patients); (2) vasculitic (8 patients); and (3) nonspecific (8 patients). The most frequent underlying abnormality in patients with subgroups 1 and 2 were the presence of homozygous methylenetetrahydrofolate reductase (MTHFR) mutations (5 of 12, 41.6%). The most common findings among subgroup 3 were the presence of antithyroid antibodies (6 of 8 patients, 75%).

CONCLUSION

Homozygous MTHFR mutations are frequently encountered in patients presenting with neurological features and MS-like or vasculitic type MRI abnormalities in a setting of autoimmune disease. Nonspecific MRI changes are frequently associated with antibodies against thyroid antigens.

Magnetic resonance imaging and computed tomography in emergency assessment of patients with suspected acute stroke: a prospective comparison

BACKGROUND

Although the use of magnetic resonance imaging (MRI) for the diagnosis of acute stroke is increasing, this method has not proved more effective than computed tomography (CT) in the emergency setting. We aimed to prospectively compare CT and MRI for emergency diagnosis of acute stroke.

METHODS

We did a single-centre, prospective, blind comparison of non-contrast CT and MRI (with diffusion-weighted and susceptibility weighted images) in a consecutive series of patients referred for emergency assessment of suspected acute stroke. Scans were independently interpreted by four experts, who were unaware of clinical information, MRI-CT pairings, and follow-up imaging.

RESULTS

356 patients, 217 of whom had a final clinical diagnosis of acute stroke, were assessed. MRI detected acute stroke (ischaemic or haemorrhagic), acute ischaemic stroke, and chronic haemorrhage more frequently than did CT (p<0.0001, for all comparisons). MRI was similar to CT for the detection of acute intracranial haemorrhage. MRI detected acute ischaemic stroke in 164 of 356 patients (46%; 95% CI 41-51%), compared with CT in 35 of 356 patients (10%; 7-14%). In the subset of patients scanned within 3 h of symptom onset, MRI detected acute ischaemic stroke in 41 of 90 patients (46%; 35-56%); CT in 6 of 90 (7%; 3-14%). Relative to the final clinical diagnosis, MRI had a sensitivity of 83% (181 of 217; 78-88%) and CT of 26% (56 of 217; 20-32%) for the diagnosis of any acute stroke.

INTERPRETATION

MRI is better than CT for detection of acute ischaemia, and can detect acute and chronic haemorrhage; therefore it should be the preferred test for accurate diagnosis of patients with suspected acute stroke. Because our patient sample encompassed the range of disease that is likely to be encountered in emergency cases of suspected stroke, our results are directly applicable to clinical practice.

NF1 plexiform neurofibroma growth rate by volumetric MRI: Relationship to age and body weight

OBJECTIVE

To longitudinally analyze changes in plexiform neurofibroma (PN) volume in relation to age and body growth in children and young adults with neurofibromatosis type 1 and inoperable, symptomatic, or progressive PNs, using a sensitive, automated method of volumetric MRI analysis.

METHODS

We included patients 25 years of age and younger with PNs entered in a natural history study or in treatment trials who had volumetric MRI over > or =16 months.

RESULTS

We studied 49 patients (median age 8.3 years) with 61 PNs and a median evaluation period of 34 months (range 18 to 70). The PN growth rates varied among patients, but were constant within patients. Thirty-four patients (69%) experienced > or =20% increase in PN volume during the observation period. PN volume increased more rapidly than body weight over time (p = 0.026). Younger patients had the most rapid PN growth rate.

CONCLUSIONS

Volume increase of plexiform neurofibromas is a realistic and meaningful trial endpoint. In most patients plexiform neurofibroma growth rate exceeded body growth rate. The youngest patients had the fastest plexiform neurofibroma growth rate, and clinical drug development should be directed toward this population. Age stratification for clinical trials for plexiform neurofibromas should be considered.

Anti-N-methyl-D-aspartate receptor antibodies, cognitive dysfunction, and depression in systemic lupus erythematosus

OBJECTIVE

To assess the association of cognitive dysfunction and depression with serum antibodies to N-methyl-D-aspartate (NMDA) receptor (anti-NR2) and analyze clinical and neuroimaging correlates in patients with systemic lupus erythematosus (SLE).

METHODS

Sixty patients underwent neurocognitive assessment, evaluation for depression with the Beck Depression Inventory II (BDI-II) and psychiatric interview (Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition [DSM-IV] criteria), brain magnetic resonance imaging, and proton magnetic resonance spectroscopy imaging (1H-MRSI). Cognition was assessed in 5 domains: memory, attention/executive, visuospatial, motor, and psychomotor, and adjusted to each individual's best level of prior cognitive functioning estimated from the reading subtest of the Wide Range Achievement Test-3 (WRAT-3). Serum anti-NR2 antibodies were measured by enzyme-linked immunosorbent assay using a pentapeptide from the human NMDA receptor.

RESULTS

Cognitive dysfunction was found in 28 of 60 patients (mild in 8, moderate in 20) before adjustment for WRAT-3 and in 35 of 60 patients (mild in 15, moderate in 11, and severe in 9) after adjustment for WRAT-3. The changes were most pronounced in the memory and visuospatial domains. There was no significant association between anti-NR2 antibody levels and cognition. On 1H-MRSI, patients with moderate or severe cognitive dysfunction had significantly higher choline:creatine ratios in the dorsolateral prefrontal cortex and the white matter, compared with patients with mild or absent cognitive dysfunction. Anti-NR2 antibodies were significantly correlated with BDI scores; patients with BDI-II scores of > or =14 had higher serum levels of anti-NR2 antibodies (P = 0.005, 95% confidence interval 0.83, 4.31), and there was a trend toward higher anti-NR2 antibody levels among patients who fulfilled the DSM-IV criteria for major depression.

CONCLUSION

Serum anti-NR2 antibodies are associated with depressive mood but not with cognitive dysfunction in SLE at a given time point. Larger longitudinal studies are needed to address the possible association between anti-NR2 antibodies and depression in SLE.

Hypothalamic hamartomas and seizures: distinct natural history of isolated and Pallister-Hall syndrome cases

PURPOSE

Hypothalamic hamartomas (HHs) have been associated with uncontrolled seizures, and aggressive therapy including surgery is often recommended. However, some patients, particularly those with other findings associated with Pallister-Hall syndrome (PHS), have a more benign course.

METHODS

Thirty-seven of 40 PHS patients and 16 of 16 patients with isolated HH had a lesion confirmed on magnetic resonance imaging (MRI). Records for all patients were reviewed for the following information: presence of seizures, age at seizure onset, seizure type, seizure frequency, number of antiepileptic medications (AEDs) at the time of evaluation, past AEDs, MRI characteristics of the HH, presence of endocrine dysfunction, and presence of developmental and behavioral problems.

RESULTS

All isolated HH patients had a history of seizures, compared with 13 of 40 PHS patients (all PHS patients with seizures had hamartomas). In isolated HH, seizures started earlier in life, occurred more frequently, and were harder to control than those in patients with PHS. Isolated HH patients were more likely to have behavioral and developmental problems than were PHS patients. The T2 signal of the hamartoma was isointense to gray matter in the majority of PHS patients, but showed a significant increase in all but one patient with isolated HH.

CONCLUSIONS

Patients with isolated HH have a distinct clinical phenotype, showing more severe seizures and neurologic dysfunction, HH showing increased T2 signal, and are more likely to have precocious puberty. In contrast, PHS patients usually have well-controlled seizures and other endocrine disturbances than precocious puberty. Patients with HH with or without seizures should be evaluated carefully for other clinical manifestations of PHS, particularly before surgery is considered.

Automated detection and volume measurement of plexiform neurofibromas in neurofibromatosis 1 using magnetic resonance imaging

An automated technique for segmentation and volumetric measurement of plexiform neurofibromas (PN) in neurofibromatosis 1 using short T1-inversion recovery magnetic resonance images is presented. The algorithm described implements heuristics derived from human-based recognition of lesions. This technique combines region-based with boundary-based segmentation. Two observers, who performed semi-automated volume calculations and manual tracings to estimate tumor volume, validated this method on 9 PNs of different size and location. This automated method was reproducible (coefficient of variation 0.6-5.6%), yielded similar results to manual tumor tracings (R = 0.999) and will likely improve the ability to measure PNs in ongoing clinical trials.

Comparison of MRI and CT for detection of acute intracerebral hemorrhage

CONTEXT

Noncontrast computed tomography (CT) is the standard brain imaging study for the initial evaluation of patients with acute stroke symptoms. Multimodal magnetic resonance imaging (MRI) has been proposed as an alternative to CT in the emergency stroke setting. However, the accuracy of MRI relative to CT for the detection of hyperacute intracerebral hemorrhage has not been demonstrated.

OBJECTIVE

To compare the accuracy of MRI and CT for detection of acute intracerebral hemorrhage in patients presenting with acute focal stroke symptoms.

DESIGN, SETTING, AND PATIENTS

A prospective, multicenter study was performed at 2 stroke centers (UCLA Medical Center and Suburban Hospital, Bethesda, Md), between October 2000 and February 2003. Patients presenting with focal stroke symptoms within 6 hours of onset underwent brain MRI followed by noncontrast CT.

MAIN OUTCOME MEASURES

Acute intracerebral hemorrhage and any intracerebral hemorrhage diagnosed on gradient recalled echo (GRE) MRI and CT scans by a consensus of 4 blinded readers.

RESULTS

The study was stopped early, after 200 patients were enrolled, when it became apparent at the time of an unplanned interim analysis that MRI was detecting cases of hemorrhagic transformation not detected by CT. For the diagnosis of any hemorrhage, MRI was positive in 71 patients with CT positive in 29 (P<.001). For the diagnosis of acute hemorrhage, MRI and CT were equivalent (96% concordance). Acute hemorrhage was diagnosed in 25 patients on both MRI and CT. In 4 other patients, acute hemorrhage was present on MRI but not on the corresponding CT--each of these 4 cases was interpreted as hemorrhagic transformation of an ischemic infarct. In 3 patients, regions interpreted as acute hemorrhage on CT were interpreted as chronic hemorrhage on MRI. In 1 patient, subarachnoid hemorrhage was diagnosed on CT but not on MRI. In 49 patients, chronic hemorrhage, most often microbleeds, was visualized on MRI but not on CT.

CONCLUSION

MRI may be as accurate as CT for the detection of acute hemorrhage in patients presenting with acute focal stroke symptoms and is more accurate than CT for the detection of chronic intracerebral hemorrhage.

Magnetic resonance imaging-based volumetry differentiates progressive supranuclear palsy from corticobasal degeneration

Because there are no biological markers for the clinical diagnosis of progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD), we established a mathematical model based on three-dimensional magnetic resonance (MR) imaging to differentiate between these parkinsonian disorders. Using MR imaging-based volumetry we studied the pattern of atrophic changes in patients with probable, possible or definite PSP (n = 33) or CBD (n = 18). Patients were compared with 22 controls with similar age. To establish a mathematical model that would allow for differentiation of PSP, CBD and controls we performed a discriminant analysis. We found a significant reduction in average brain, brainstem, midbrain and frontal gray matter volumes in patients with PSP, whereas patients with CBD showed atrophy of parietal cortex and corpus callosum. With the exception of reduced midbrain volumes in PSP, the measured volumes of anatomical structures showed an extensive overlap with the normal range on an individual basis. Using only post mortem confirmed cases of PSP (n = 8) and CBD (n = 7) as well as all controls, the volumes of midbrain, parietal white matter, temporal gray matter, brainstem, frontal white matter and pons were identified to separate best between groups and were used to construct a model with two canonical variables. This model allowed to correctly predict the diagnosis in 95% of controls as well as in 76% of all PSP and 83% of all CBD patients. Similar results were obtained only when patients with a possible and probable diagnosis of PSP and CBD, who were not involved in the development of the discriminant analysis, were classified. 3D-MR imaging-based volumetry may help to differentiate PSP from CBD ante mortem.

Pituitary magnetic resonance imaging in 15 patients with Prop1 gene mutations: pituitary enlargement may originate from the intermediate lobe

Pituitary morphology in patients with Prop1 gene mutations varies. Most patients demonstrate a normal or small pituitary gland. Occasionally, pituitary enlargement of undetermined origin has also been detected. In the present study we use long-term magnetic resonance imaging findings to characterize the morphological abnormalities of the pituitary gland in 15 patients (aged 2.5-45 yr) with combined pituitary hormone deficiency caused by Prop1 gene mutations (GA296del/GA296del in seven, GA296del/A150del in two, A150del/A150del in five, and GA296del/R73H in one patient) and attempt to uncover the origin and nature of the pituitary enlargement. Small pituitary gland was detected in seven patients (25.2 +/- 14.4 yr of age), normal pituitary size in three patients (10.2 +/- 5.8 yr of age), and pituitary enlargement in five patients (6.5 +/- 2.7 yr of age). The pituitary enlargement consisted of a nonenhancing mass lesion interposed between the normally enhancing anterior lobe and the neurohypophysis. The pituitary stalk was displaced anteriorly, whereas the neurohypophysis was orthotopic, displaying a normal signal. Spontaneous regression of the mass lesion with normalization of the pituitary stalk position was observed in three patients. Our data indicate that although a small pituitary gland is usually observed in older subjects, a significant number of young patients with Prop1 gene mutations demonstrate pituitary enlargement with subsequent regression. The distinct magnetic resonance imaging characteristics of the pituitary enlargement in our patients in conjunction with pertinent data from Prop1-deficient mice suggest that the mass causing the pituitary enlargement most likely originates from the intermediate lobe.

Cerebrospinal fluid levels of catechols in patients with neurogenic orthostatic hypotension

In multiple system atrophy (MSA) and pure autonomic failure (PAF), orthostatic hypotension (OH) results from deficient noradrenaline release from sympathetic nerves during standing. Post-mortem findings have indicated loss of central noradrenergic cells in both diseases. The present study sought in vivo neurochemical evidence for central noradrenergic deficiency in patients with OH due to MSA or PAF. A total of 28 patients with OH (18 with MSA; 10 with PAF) had cerebrospinal fluid and blood sampled for levels of noradrenaline and its neuronal metabolite dihydroxyphenylglycol. A control group of 44 subjects included 10 elderly normal volunteers, 10 patients with Alzheimer's disease, 18 patients with dysautonomia (postural tachycardia syndrome or neurocardiogenic syncope) and six patients with MSA in the absence of OH. Patients with OH had lower cerebrospinal fluid concentrations of noradrenaline (0.53+/-0.07 nmol/l) and dihydroxyphenylglycol (6.52+/-0.46 nmol/l) than did control subjects (0.90+/-0.09 and 9.64+/-0.46 nmol/l respectively; P =0.0001). The MSA+OH group had higher plasma levels of both catechols (noradrenaline, 1.31+/-0.16 nmol/l; dihydroxyphenylglycol, 5.08+/-0.43 nmol/l) than did the PAF group (noradrenaline, 0.38+/-0.08 nmol/l; dihydroxyphenylglycol, 2.53+/-0.30 nmol/l; P <0.001), despite similarly low cerebrospinal fluid levels. Among MSA patients, those with OH had lower cerebrospinal fluid levels of noradrenaline and dihydroxyphenylglycol than those without OH (noradrenaline, 1.71+/-0.64 nmol/l; dihydroxyphenylglycol, 10.41+/-1.77 nmol/l respectively; P =0.006). The findings are consistent with central noradrenergic deficiency in both MSA+OH and PAF. In MSA, central noradrenergic deficiency seems to relate specifically to OH.

Pituitary apoplexy induced by corticotrophin-releasing hormone in a patient with Cushing's disease

Pituitary apoplexy can occur spontaneously or following anterior pituitary stimulation tests. Apoplexy is a rare complication of Cushing's disease. We report a 19-year-old woman who was admitted to the National Institutes of Health for evaluation of possible Cushing's syndrome. Her symptoms and initial laboratory work were suggestive of Cushing's disease. Magnetic resonance imaging (MRI) revealed a macroadenoma of the pituitary gland. As part of her evaluation she received corticotrophin-releasing hormone (CRH). Two days later she developed severe headache, accompanied by nausea and vomiting, followed by meningismus, ptosis and diplopia. A diagnosis of pituitary apoplexy was made and she was treated conservatively with dexamethasone. Her neurological symptoms resolved shortly afterwards. By the time of discharge her anterior pituitary function was suppressed. All symptoms and signs of Cushing's syndrome resolved thereafter. This is the first case to demonstrate that CRH administration can induce pituitary apoplexy in a patient with Cushing's disease. Therapy with glucocorticoids was effective in our case, suggesting that conservative treatment can be successfully and safely applied in certain cases with pituitary apoplexy.

Spoiled gradient recalled acquisition in the steady state technique is superior to conventional postcontrast spin echo technique for magnetic resonance imaging detection of adrenocorticotropin-secreting pituitary tumors

Recent studies show that the standard T1-weighted spin echo (SE) technique for magnetic resonance imaging (MRI) fails to identify 40% of corticotrope adenomas. We hypothesized that the superior soft tissue contrast and thinner sections obtained with spoiled gradient recalled acquisition in the steady state (SPGR) would improve tumor detection. We compared the performance of SE and SPGR MRI in 50 patients (age, 7-67 yr) with surgically confirmed corticotrope adenoma. Coronal SE and SPGR MR images were obtained before and after administration of gadolinium contrast, using a 1.5 T scanner. SE scans were obtained over 5.1 min (12-cm field of view; interleaved sections, 3 mm). SPGR scans were obtained over 3.45 min (12- or 18-cm field of view, contiguous 1- or 2-mm slices). The MRI interpretations of two radiologists were compared with findings at surgical resection. Compared with SE for detection of tumor, SPGR had superior sensitivity (80%; confidence interval, 68-91; vs. 49%; confidence interval, 34-63%), but a higher false positive rate (2% vs. 4%). We recommend the addition of SPGR to SE sequences using pituitary-specific technical parameters to improve the MRI detection of ACTH-secreting pituitary tumors.

Mixing during intravertebral arterial infusions in an in vitro model

Regional delivery of drugs can offer a pharmacokinetic advantage in the treatment of localized tumors. One method of regional delivery is by intra-arterial infusion into the basilar/vertebral artery network that provides local access to infratentorial tumors, which are frequent locations of childhood brain cancers. Proper delivery of drug by infused solutions requires adequate mixing of the infusate at the site of infusion within the artery lumen. Our mixing studies with an in vitro model of the vertebral artery network indicate that streaming of drug solution is likely to occur at low, steady infusion rates of 2 ml/min. Streaming leads to maldistribution of drug to distal perfused brain regions and may result in toxic levels in some regions while concurrently yielding subtherapeutic levels in adjacent regions. According to our model findings, distribution to both brain hemispheres is not likely following infusion into a single vertebral artery even if the infusate is well-mixed at the infusion site. This outcome results from the unique fluid flow properties of two converging channels, which are represented by the left and right vertebral branches converging into the basilar. Fluid in the model remains stratified on the side of the basilar artery served by the infused vertebral artery. Careful thought and planning of the methods of intravertebral drug infusions for treating posterior fossa tumors are required to assure proper distribution of the drug to the desired tissue regions. Improper delivery may be responsible for some noted toxicities or for failure of the treatments.

Phase I trial of lobradimil (RMP-7) and carboplatin in children with brain tumors

PURPOSE

To determine the maximum tolerated dose (MTD), the incidence and severity of toxicities, and the pharmacokinetics of lobradimil administered intravenously over 10 min in combination with carboplatin in children with refractory brain tumors.

METHODS

A group of 25 children with primary brain tumors received carboplatin and lobradimil on two consecutive days every 28 days. The 10-min lobradimil infusion began 5 min before the end of the carboplatin infusion. Four lobradimil dose levels (100, 300, 450 and 600 ng/kg ideal body weight, IBW) were studied in cohorts of 4 to 13 patients. Carboplatin was adaptively dosed based on the glomerular filtration rate to achieve a target plasma area under the concentration-time curve (AUC) of 7.0 mg min/ml per course (5.0 mg min/ml for patients who had previously received craniospinal radiation or myeloablative chemotherapy).

RESULTS

Lobradimil toxicity was immediate, tolerable and rapidly reversible. The most frequent toxicities were hypotension, flushing, headache and gastrointestinal complaints. One patient on the 600 ng/kg dose level had a seizure during the lobradimil infusion. The incidence and severity of lobradimil toxicities were not dose-related and the lobradimil dose was not escalated beyond the 600 ng/kg IBW dose level. Two patients had partial responses and ten patients had stable disease. Myelosuppression (thrombocytopenia more prominent than neutropenia) was the primary toxicity attributed to carboplatin. Lobradimil pharmacokinetics were characterized by rapid clearance from the plasma compartment and substantial interpatient variability.

CONCLUSIONS

The combination of carboplatin and lobradimil is safe and tolerable. An MTD for lobradimil was not defined because toxicity was not dose-related. The recommended pediatric phase II dose of lobradimil is 600 ng/kg IBW.

Intramedullary spinal cord metastasis from renal cell carcinoma: detection by positron emission tomography

Although positron emission tomography (PET) is an established diagnostic method in brain and lung cancer, its use is often confined to research. The authors report a case of a minimally symptomatic intramedullary spinal cord metastasis, an uncommon and often diagnostically challenging lesion, that was confirmed by PET. A 37-year-old man with a history of metastatic renal cell carcinoma treated with systemic agents, an autologous stem cell transplant, and local palliative radiotherapy with a 2-month history of vague right foot numbness and right leg dysesthesias was found to have an intramedullary lesion at the level of T12. Although the findings of magnetic resonance imaging suggested central necrosis, a PET scan revealed a metabolically active lesion and confirmed the diagnosis of intramedullary metastasis. PET can be used to detect and confirm intramedullary spinal cord metastatic carcinoma. PET imaging may have a vital role in clinical diagnosis by helping to distinguish diagnostically troublesome lesions based on metabolic activity.

Comparison of one-, two-, and three-dimensional measurements of childhood brain tumors

BACKGROUND

End points for assessing drug activity in brain tumors are determined by measuring the change in tumor size by magnetic resonance imaging (MRI) relative to a pretreatment or best-response scan. Traditionally, two-dimensional (2D) tumor measurements have been used, but one-dimensional (1D) measurements have recently been proposed as an alternative. Because software to estimate three-dimensional (3D) tumor volume from digitized MRI images is available, we compared all three methods of tumor measurement for childhood brain tumors and clinical outcome.

METHODS

Tumor size from 130 MRI scans from 32 patients (32 baseline and 98 follow-up scans, for a total of 130 scans; median, three scans per patient; range, two to 18 scans) was measured by each method. Tumor-response category (partial response, minor response, stable disease, or progressive disease) was determined from the percentage change in tumor size between the baseline or best-response scan and follow-up scans. Time to clinical progression was independently determined by chart review. All statistical tests were two-sided.

RESULTS

Concordances between 1D and 2D, 1D and 3D, and 2D and 3D were 83% (95% confidence interval [CI] = 67% to 99%), 61% (95% CI = 47% to 75%), and 66% (95% CI = 52% to 80%), respectively, on follow-up scans. Concordances for 1D and 3D and for 2D and 3D were statistically significantly lower than the concordance for 1D and 2D (P< .001 and P = .003, respectively). Concordance among 1D, 2D, and 3D methods in detecting partial response was high; there was less concordance in classifying tumors in the minor response and progressive-disease categories. Median times to progression measured by the 1D, 2D, and 3D methods were 154, 105, and 112 days, respectively, compared with 114 days based on neurologic symptoms and signs (P = .09 for overall comparison).

CONCLUSIONS

Detection of partial responses was not influenced by the measurement method, but estimating time to disease progression may be method dependent for childhood brain tumors.

Ophthalmic manifestations of Allgrove syndrome: report of a case

A male patient with the ocular manifestations of Allgrove or triple-A syndrome is described. The need for early diagnosis based on alacrima, anisocoria and optic atrophy of this potentially fatal condition is stressed.

Spectroscopic imaging of radiation-induced effects in the white matter of glioma patients

External radiation therapy of brain tumors may cause adverse effects on normal brain tissue, resulting in severe neuropsychological and cognitive impairment. We investigated the late delayed radiation effects in the white matter (WM) using (1)H magnetic resonance spectroscopic imaging ((1)HMRSI). Nine glioma patients with local radiation-induced signal abnormalities in the T(2)-weighted MR images were studied with nine age- and sex-matched controls. The metabolite ratios in the radiation-induced hyper intensity area (RIHA) and in the normal appearing white matter (NAWM) of the patients were compared with respective WM areas of the controls. In RIHA, choline/creatine (Cho/Cr) was 17% decreased (1.22 +/- 0.13 vs 1.47 +/- 0.16, p = 0.0027, significant (s), unpaired Student's t test with Bonferroni correction) in the patients compared to the controls, while there was no difference in N-acetyl aspartate/Cr (NAA/Cr) (2.49 +/- 0.57 vs 2.98 +/- 0.32, p = 0.039) or NAA/Cho (2. 03 +/- 0.40 vs 2.04 +/- 0.17, p = 0.95). In NAWM, Cho/Cr was 24% decreased (1.21 +/- 0.15 vs 1.59 +/- 0.13, p < 0.0001, s) and NAA/Cho was 20% increased (2.49 +/- 0.49 vs 1.98 +/- 0.15, p = 0. 0082, s) in the patients compared to the controls, while there was no difference in NAA/Cr (2.99 +/- 0.46 vs 3.16 +/- 0.32, p = 0.38). NAA(RIHA)/NAA(NAWM) was 25% decreased (0.75 +/- 0.20 vs 1.00 +/- 0. 12, p = 0.0043, s) and Cr(RIHA)/Cr(NAWM) was 16% decreased (0.89 +/- 0.15 vs 1.06 +/- 0.10, p = 0.013, s) in the patients compared to the controls, while there was no difference in Cho(RIHA)/Cho(NAWM) (0.92 +/- 0.23 vs 0.98 +/- 0.10, p = 0.47). (1)HMRSI reveals widespread chemical changes in the WM after radiation therapy. In RIHA, there is loss of NAA, Cho, and Cr implying axonal and membrane damage and in NAWM, there is loss of Cho, reflecting membrane damage.

Intratumoral administration of recombinant circularly permuted interleukin-4-Pseudomonas exotoxin in patients with high-grade glioma

Human glioblastoma but not normal brain cells express numerous receptors for the cytokine interleukin (IL)-4. To target these receptors, we have investigated the safety and activity of directly infusing IL-4(38-37)-PE38KDEL, a chimeric protein composed of circularly permuted IL-4 and a truncated form of Pseudomonas exotoxin (PE), into recurrent malignant high-grade gliomas. IL-4(38-37)-PE38KDEL (IL-4-toxin) was infused over a 4-8-day period into gliomas of nine patients by one to three stereotactically placed catheters. No apparent systemic toxicity occurred in any patient. The infusion of IL-4-toxin in six of nine patients showed glioma necrosis as evidenced by diminished gadolinium enhancement on magnetic resonance imaging. Seven of nine patients underwent craniotomy because of increased intracranial pressure at 16-101 days after the beginning of infusion. In six of these seven patients, partial-to-extensive tumor necrosis with edema was confirmed pathologically. No histological evidence of neurotoxicity to normal brain was identified in any patient. Two patients were not operated on; by magnetic resonance imaging, one showed mottled gadolinium enhancement, and the other showed extensive necrosis of tumor leading to complete remission; this patient remains disease-free > 18 months after the procedure. We conclude that direct glioma injection of IL-4(38-37)-PE38KDEL is safe without systemic toxicity. Local toxicity seemed attributable mainly to tumor necrosis or occasionally to the volume of infusion. Histological evidence of toxicity to normal brain was not observed and in many patients, could be pathologically excluded. Additional patients are being treated to determine the maximal tolerated concentration and volume of IL-4(38-37)-PE38KDEL.

Language disturbances in corticobasal degeneration

To characterize the language deficits in corticobasal degeneration (CBD) and their relation to neuroradiologic findings, the authors administered a standardized battery of neurobehavioral tests and performed MRI studies on 15 patients with CBD. Eight patients (53%) had classifiable aphasias, including anomic, Broca's and transcortical motor aphasias. The aphasias were associated primarily with left frontal and parietal cortical damage and subcortical white matter and corpus callosum abnormalities. Our findings demonstrate that language disturbances in CBD are more frequent than previously considered.

Elucidating the pathophysiology of syringomyelia

OBJECT

Syringomyelia causes progressive myelopathy. Most patients with syringomyelia have a Chiari I malformation of the cerebellar tonsils. Determination of the pathophysiological mechanisms underlying the progression of syringomyelia associated with the Chiari I malformation should improve strategies to halt progression of myelopathy.

METHODS

The authors prospectively studied 20 adult patients with both Chiari I malformation and symptomatic syringomyelia. Testing before surgery included the following: clinical examination; evaluation of anatomy by using T1-weighted magnetic resonance (MR) imaging; evaluation of the syrinx and cerebrospinal fluid (CSF) velocity and flow by using phase-contrast cine MR imaging; and evaluation of lumbar and cervical subarachnoid pressure at rest, during the Valsalva maneuver, during jugular compression, and following removal of CSF (CSF compliance measurement). During surgery, cardiac-gated ultrasonography and pressure measurements were obtained from the intracranial, cervical subarachnoid, and lumbar intrathecal spaces and syrinx. Six months after surgery, clinical examinations, MR imaging studies, and CSF pressure recordings were repeated. Clinical examinations and MR imaging studies were repeated annually. For comparison, 18 healthy volunteers underwent T1-weighted MR imaging, cine MR imaging, and cervical and lumbar subarachnoid pressure testing. Compared with healthy volunteers, before surgery, the patients had decreased anteroposterior diameters of the ventral and dorsal CSF spaces at the foramen magnum. In patients, CSF velocity at the foramen magnum was increased, but CSF flow was reduced. Transmission of intracranial pressure across the foramen magnum to the spinal subarachnoid space in response to jugular compression was partially obstructed. Spinal CSF compliance was reduced, whereas cervical subarachnoid pressure and pulse pressure were increased. Syrinx fluid flowed inferiorly during systole and superiorly during diastole on cine MR imaging. At surgery, the cerebellar tonsils abruptly descended during systole and ascended during diastole, and the upper pole of the syrinx contracted in a manner synchronous with tonsillar descent and with the peak systolic cervical subarachnoid pressure wave. Following surgery, the diameter of the CSF passages at the foramen magnum increased compared with preoperative values, and the maximum flow rate of CSF across the foramen magnum during systole increased. Transmission of pressure across the foramen magnum to the spinal subarachnoid space in response to jugular compression was normal and cervical subarachnoid mean pressure and pulse pressure decreased to normal. The maximum syrinx diameter decreased on MR imaging in all patients. Cine MR imaging documented reduced velocity and flow of the syrinx fluid. Clinical symptoms and signs improved or remained stable in all patients, and the tonsils resumed a normal shape.

CONCLUSIONS

The progression of syringomyelia associated with Chiari I malformation is produced by the action of the cerebellar tonsils, which partially occlude the subarachnoid space at the foramen magnum and act as a piston on the partially enclosed spinal subarachnoid space. This creates enlarged cervical subarachnoid pressure waves that compress the spinal cord from without, not from within, and propagate syrinx fluid caudally with each heartbeat, which leads to syrinx progression. The disappearance of the abnormal shape and position of the tonsils after simple decompressive extraarachnoidal surgery suggests that the Chiari I malformation of the cerebellar tonsils is acquired, not congenital. Surgery limited to suboccipital craniectomy, C-I laminectomy, and duraplasty eliminates this mechanism and eliminates syringomyelia and its progression without the risk of more invasive procedures.

Elucidating the pathophysiology of syringomyelia

Object

Syringomyelia causes progressive myelopathy. Most patients with syringomyelia have a Chiari I malformation of the cerebellar tonsils. Determination of the pathophysiological mechanisms underlying the progression of syringomyelia associated with the Chiari I malformation should improve strategies to halt progression of myelopathy.

Methods

The authors prospectively studied 20 adult patients with both Chiari I malformation and symptomatic syringomyelia. Testing before surgery included the following: clinical examination; evaluation of anatomy by using T1-weighted magnetic resonance (MR) imaging; evaluation of the syrinx and cerebrospinal fluid (CSF) velocity and flow by using phase-contrast cine MR imaging; and evaluation of lumbar and cervical subarachnoid pressure at rest, during the Valsalva maneuver, during jugular compression, and following removal of CSF (CSF compliance measurement). During surgery, cardiac-gated ultrasonography and pressure measurements were obtained from the intracranial, cervical subarachnoid, and lumbar intrathecal spaces and syrinx. Six months after surgery, clinical examinations, MR imaging studies, and CSF pressure recordings were repeated. Clinical examinations and MR imaging studies were repeated annually. For comparison, 18 healthy volunteers underwent T1-weighted MR imaging, cine MR imaging, and cervical and lumbar subarachnoid pressure testing.

Compared with healthy volunteers, before surgery, the patients had decreased anteroposterior diameters of the ventral and dorsal CSF spaces at the foramen magnum. In patients, CSF velocity at the foramen magnum was increased, but CSF flow was reduced. Transmission of intracranial pressure across the foramen magnum to the spinal subarachnoid space in response to jugular compression was partially obstructed. Spinal CSF compliance was reduced, whereas cervical subarachnoid pressure and pulse pressure were increased. Syrinx fluid flowed inferiorly during systole and superiorly during diastole on cine MR imaging. At surgery, the cerebellar tonsils abruptly descended during systole and ascended during diastole, and the upper pole of the syrinx contracted in a manner synchronous with tonsillar descent and with the peak systolic cervical subarachnoid pressure wave. Following surgery, the diameter of the CSF passages at the foramen magnum increased compared with preoperative values, and the maximum flow rate of CSF across the foramen magnum during systole increased. Transmission of pressure across the foramen magnum to the spinal subarachnoid space in response to jugular compression was normal and cervical subarachnoid mean pressuree and pulse pressure decreased to normal. The maximum syrinx diameter decreased on MR imaging in all patients. Cine MR imaging documented reduced velocity and flow of the syrinx fluid. Clinical symptoms and signs improved or remained stable in all patients, and the tonsils resumed a normal shape.

Conclusions

The progression of syringomyelia associated with Chiari I malformation is produced by the action of the cerebellar tonsils, which partially occlude the subarachnoid space at the foramen magnum and act as a piston on the partially enclosed spinal subarachnoid space. This creates enlarged cervical subarachnoid pressure waves that compress the spinal cord from without, not from within, and propagate syrinx fluid caudally with each heartbeat, which leads to syrinx progression. The disappearance of the abnormal shape and position of the tonsils after simple decompressive extraarachnoidal surgery suggests that the Chiari I malformation of the cerebellar tonsils is acquired, not congenital. Surgery limited to suboccipital craniectomy, C-1 laminectomy, and duraplasty eliminates this mechanism and eliminates syringomyelia and its progression without the risk of more invasive procedures.

Trypanosoma cruzi meningoencephalitis in HIV-infected patients

Five cases of Trypanosoma cruzi meningoencephalitis in HIV-infected patients are reported. All patients presented with mass lesions on head computed tomographic scan, trypanosomes in the cerebrospinal fluid and failure to respond to antitoxoplasmosis therapy. Benznidazole therapy was associated with clinical improvement in 1 patient. Another 4 patients had T cruzi identified in a peripheral smear. T cruzi needs to be considered in the differential diagnosis of HIV-infected patients with central nervous system mass lesions if they have a history of appropriate exposure.

MR image segmentation and tissue metabolite contrast in 1H spectroscopic imaging of normal and aging brain

The impact of image segmentation on 0.84-ml nominal voxel volume proton spectroscopic imaging in normal brain and in age-related cortical atrophy was investigated. Segmentation improved the gray matter-white matter (GM-WM) contrast for N-acetyl aspartate (NAA)/creatine (Cr) and choline (Cho)/Cr in normal brain, and for NAA/Cho and NAA/Cr in atrophic brain. NAA(GM/WM) (approximately 0.7), Cho(GM/WM) (approximately 0.8), and Cr(GM/WM) (approximately 1.3) in normal brain obtained with segmentation agreed with values obtained with quantitative magnetic resonance spectroscopy. Age-related cortical atrophy led to decreased cortical GM NAA/Cho and NAA/Cr; no changes were evident in WM or in NAA(GM/WM), Cho(GM/WM), or Cr(GM/WM). GM/WM metabolite analysis may be of limited use in conditions in which parallel metabolite changes occur in WM and GM.

Phase II trial of chemotherapy alone for primary CNS and intraocular lymphoma

PURPOSE

Primary CNS lymphoma (PCNSL) and primary intraocular lymphoma (IOL) are usually treated with radiation therapy alone or in combination with chemotherapy. The neurotoxicity of these treatments can be substantial. This study attempts to define the toxicity and efficacy of the treatment of this disease with chemotherapy alone.

PATIENTS AND METHODS

Fourteen nonimmunocompromised patients were accrued to a chemotherapy regimen that incorporated a 24-hour infusion of high-dose methotrexate total dose of 8.4 g/m2 with leucovorin rescue; thiotepa 35 mg/m2; vincristine 1.4 mg/m2; dexamethasone; and intrathecal cytarabine (Ara-C) and methotrexate (MTV) administered in 21-day cycles. Seven patients were prospectively followed up with formal neuropsychologic assessments for evidence of CNS toxicity.

RESULTS

The response rate was 100% with 11 (79%) complete responses and three (21%) partial responses. Cumulative survival and progression-free survival rates at more than 4.5 years were 68.8% and 34.3%, respectively. Median survival has not been reached, and median progression-free survival was 16.5 months. Toxicity included severe leukoencephalopathy that was clearly attributable to chemotherapy (two patients), grade 3 or 4 neutropenia in 50% of the cycles administered, ileus (one patient), and seizures (two patients). Mucositis and renal and hepatic toxicity were mild and not therapy limiting.

CONCLUSION

The MTV regimen is generally well tolerated and produces a high complete response rate. Chemotherapy alone should be investigated further in this disease to assess the necessity of initial radiation therapy, either alone or in combined modality regimens, for the achievement of optimal response and survival.