MRI Investigation Research Articles

Stimulating learning: A functional MRI and behavioral investigation of the effects of transcranial direct current stimulation on stochastic learning in schizophrenia

Transcranial direct current stimulation (tDCS) of the medial prefrontal cortex (mPFC) is under clinical investigation as a treatment for cognitive deficits. We investigate the effects of tDCS over the mPFC on performance SSLT in individuals with schizophrenia, and the underlying neurophysiological effect in regions associated with learning values and stimulus-outcome relationships. In this parallel-design double-blind pilot study, 49 individuals with schizophrenia, of whom 28 completed a fMRI, were randomized into active or sham tDCS stimulation groups. Subjects participated in 4 days of SSLT training (days 1, 2, 14, 56) with tDCS applied at day-1, and during a concurrent MRI scan at day-14. The SSLT demonstrated a significant mean difference in performance in the tDCS treatment group: at day-2 and at day-56. Active tDCS was associated with increased insular activity, and reduced amygdala activation. tDCS may offer an important novel approach to modulating brain networks to ameliorate cognitive deficits in schizophrenia, with this study being the first to show a longer-term effect on SSLT.

A comparative study of conventional magnetic resonance sequences with 2D time of flight sequence versus contrast enhanced magnetic resonance venography in diagnosing cerebral venous sinus thrombosis

Background: The present study aimed to compare the accuracy between conventional MRV with 2D Time of Flight sequence versus contrast enhanced MRV in Cerebral venous sinus thrombosis.Materials and methods: This was a hospital based ambispective study that was conducted from Jan 2021 to Jun 2022 in Department of Radiodiagnosis in Mahatma Gandhi Medical College and Research Institute (MGMCRI), Pondicherry after obtaining approval from Ethical Committee. Patients admitted in MGMCRI as clinically suspected cases of CVT was included for the study. It was an ambispective study, so included records of patients retrospectively from JAN 2019 to DEC 2020 and prospectively from JAN 2021 to MAY 2022 in Mahatma Gandhi Medical College and Research Institute.Results: The study was conducted as a hospital based ambispective study comprising 30 patients of either sex.Majority of the study participants were in the age group of less than 25 years and were females (73.3%). Majority of the female study participants were in puerperium. Majority of the study patients had headache on presentation (73.3%). Sensitivity and specificity of MR TOF in diagnosing SSS thrombosis was 92.31% and 50% respectively. Sensitivity and specificity of MR TOF in diagnosing LS thrombosis was 79.17% and 33.33% respectively. Sensitivity and specificity of MR TOF in diagnosing STS thrombosis was 100% and 34.78% respectively.Conclusion: Multicentric large scale studies involving patients from different backgrounds of variable demography was required to clearly establish the accuracy of MRI investigations. The performance of contrast enhanced 3D MRV was superior in terms of picture quality and evaluation of all sinuses and veins. The findings of our study contributed to the body of data supporting the advantages of contrast enhanced 3D MR venography over 2D TOF MR Venography in the routine clinical diagnosis or exclusion of acute CVT.

Rhinocerebral Form of Invasive Mycosis in COVID-19 Patients: Clinical Course, Diagnosis, Treatment Experience

Background. The incidence of invasive mycoses is reported to increase among patients with a history of new coronavirus infection COVID-19. Adhesion and damage of endothelial cells by zygomycetes lead to fungus angioinvasion, release of a large number of fungal proteases, lipases and mycotoxins, as well as vascular thrombosis, subsequent necrosis of tissues.Objectives. Improvement of the diagnosis and treatment for COVID-19 associated invasive mycosis.Methods. Examination and treatment of 143 patients with invasive mycosis of the maxillofacial area in the period from August 2021 to May 2022 at the Maxillofacial Unit of Regional Clinical Hospital of Emergency Medical Care, Krasnodar Krai, Russia. The diagnosis was confi rmed by cytological, culture-based methods, as well as pathomorphological study of surgical specimen. Follow-up monitoring was carried out in 1, 3, 6 months, with repeated CT and MRI investigations. The group under follow-up monitoring included 91 patients. The incidence of signs was determined via descriptive statistics methods in proportion of the total number of observations and expressed as a percentage. Statistika 12.5 and Excel 2010 (Windows 10) were used in the study, the graphical representation of the material was made in the same programs.Results. Manifestation of invasive mycoses of the maxillofacial area occurred during the early convalescent period of coronavirus infection in specialized infectious hospitals or within two weeks after discharge from the hospital. A typical clinical picture includes rhinocerebral zygomycosis with the development of fungal osteomyelitis of the upper jaw, nasal bones, zygomatic bone, ethmoidal labyrinth bones, sphenoid bone, frontal bone. 17 cases (11.9%) had a lethal outcome as a result of disseminated form of fungal infection caused by Mucorales (14 patients), Aspergillus (3 patients) with damage to the brain, lungs, kidneys and fatal massive necrotic lesions of the craniofacial area. An integrated approach embraced early antifungal therapy (Amphotericin B) as well as surgical debridement of the lesions and provided a positive effect in treatment.Conclusion. Invasive fungal infections require prompt diagnosis and early prescription of antifungal therapy (prior to histological confi rmation of diagnosis) to minimize consequences and prevent fatal outcome. Due to the nonspecifi c nature of clinical symptoms and diffi culties of early diagnosis of invasive zygomycosis and aspergillosis, it is necessary to be alert to potential invasive aggressive mycoses in immunocompromised patients who have a history of a new coronavirus infection COVID-19.

SOC-I-10 MRI Investigations of total and local CSF volumes in juvenile and mature nonhuman primates for the preclinical safety assessment of antisense oligonucleotides

SOC-I-10 MRI Investigations of total and local CSF volumes in juvenile and mature nonhuman primates for the preclinical safety assessment of antisense oligonucleotides

Minimal number of sampling directions for robust measures of the spherical mean diffusion weighted signal: Effects of sampling directions, b-value, signal-to-noise ratio, hardware, and fitting strategy

Several recent multi-compartment diffusion MRI investigations and modeling strategies have utilized the orientationally-averaged, or spherical mean, diffusion-weighted signal to study tissue microstructure of the central nervous system. Most experimental designs sample a large number of diffusion weighted directions in order to calculate the spherical mean signal, however, sampling a subset of these directions may increase scanning efficiency and enable either a decrease in scan time or the ability to sample more diffusion weightings. Here, we aim to determine the minimum number of gradient directions needed for a robust measurement of the spherical mean signal. We used computer simulations to characterize the variation of the measured spherical mean signal as a function of the number of gradient directions, while also investigating the effects of diffusion weighting (b-value), signal-to-noise ratio (SNR), available hardware, and spherical mean fitting strategy. We then utilize empirically acquired data in the brain and spinal cord to validate simulations, showing experimental results are in good agreement with simulations. We summarize these results by providing an intuitive lookup table to facilitate the determination of the minimal number of sampling directions needed for robust spherical mean measurements, and give recommendations based on SNR and experimental conditions.

Pro-inflammatory cytokines in cystic glioblastoma: A quantitative study with a comparison with bacterial brain abscesses. With an MRI investigation of displacement and destruction of the brain tissue surrounding a glioblastoma.

Cystic glioblastomas are aggressive primary brain tumors that may both destroy and displace the surrounding brain tissue as they grow. The mechanisms underlying these tumors’ destructive effect could include exposure of brain tissue to tumor-derived cytokines, but quantitative cytokine data are lacking. Here, we provide quantitative data on leukocyte markers and cytokines in the cyst fluid from 21 cystic glioblastomas, which we compare to values in 13 brain abscess pus samples. The concentration of macrophage/microglia markers sCD163 and MCP-1 was higher in glioblastoma cyst fluid than in brain abscess pus; lymphocyte marker sCD25 was similar in cyst fluid and pus, whereas neutrophil marker myeloperoxidase was higher in pus. Median cytokine levels in glioblastoma cyst fluid were high (pg/mL): TNF-α: 32, IL-6: 1064, IL-8: 23585, tissue factor: 28, the chemokine CXCL1: 639. These values were not significantly different from values in pus, pointing to a highly pro-inflammatory glioblastoma environment. In contrast, levels of IFN-γ, IL-1β, IL-2, IL-4, IL-10, IL-12, and IL-13 were higher in pus than in glioblastoma cyst fluid. Based on the quantitative data, we show for the first time that the concentrations of cytokines in glioblastoma cyst fluid correlate with blood leukocyte levels, suggesting an important interaction between glioblastomas and the circulation. Preoperative MRI of the cystic glioblastomas confirmed both destruction and displacement of brain tissue, but none of the cytokine levels correlated with degree of brain tissue displacement or peri-tumoral edema, as could be assessed by MRI. We conclude that cystic glioblastomas are highly pro-inflammatory environments that interact with the circulation and that they both displace and destroy brain tissue. These observations point to the need for neuroprotective strategies in glioblastoma therapy, which could include an anti-inflammatory approach.

The incidence of adverse local tissue reaction due to head taper corrosion after total hip arthroplasty using V40 taper and 36 mm CoCr head

Aims Head-taper corrosion is a cause of failure in total hip arthroplasty (THA). Recent reports have described an increasing number of V40 taper failures with adverse local tissue reaction (ALTR). However, the real incidence of V40 taper damage and its cause remain unknown. The aim of this study was to evaluate the long-term incidence of ALTR in a consecutive series of THAs using a V40 taper and identify potentially related factors. Methods Between January 2006 and June 2007, a total of 121 patients underwent THA using either an uncemented (Accolade I, made of Ti12Mo6Zr2Fe; Stryker, USA) or a cemented (ABG II, made of cobalt-chrome-molybdenum (CoCrMo); Stryker) femoral component, both with a V40 taper (Stryker). Uncemented acetabular components (Trident; Stryker) with crosslinked polyethylene liners and CoCr femoral heads of 36 mm diameter were used in all patients. At a mean folllow-up of 10.8 years (SD 1.1), 94 patients (79%) were eligible for follow-up (six patients had already undergone a revision, 15 had died, and six were lost to follow-up). A total of 85 THAs in 80 patients (mean age 61 years (24 to 75); 47 (56%) were female) underwent clinical and radiological evaluation, including the measurement of whole blood levels of cobalt and chrome. Metal artifact reduction sequence MRI scans of the hip were performed in 71 patients. Results A total of 20 ALTRs were identified on MRI, with an incidence of 26%. Patients with ALTR had significantly higher median Co levels compared with those without ALTR (2.96 μg/l (interquartile range (IQR) 1.35 to 4.98) vs 1.44 μg/l (IQR 0.79 to 2.5); p = 0.019). Radiological evidence of osteolysis was also significantly associated with ALTR (p = 0.014). Median Cr levels were not significantly higher in those with ALTR compared with those without one (0.97 μg/l (IQR 0.72 to 1.9) v 0.67 μg/l (IQR 0.5 to 1.19; p = 0.080). BMI, sex, age, type of femoral component, head length, the inclination of the acetabular component, and heterotopic ossification formation showed no significant relationship with ALTR. Conclusion Due to the high incidence of local ALTR in our cohort after more than ten years postoperatively, we recommend regular follow-up investigation even in asymptomatic patients with V40 taper and metal heads. As cobalt levels correlate with ALTR occurrence, routine metal ion screening and consecutive MRI investigation upon elevation could be discussed. Cite this article: Bone Joint J 2022;104-B(7):852–858.

Limbic-predominant age-related TDP-43 encephalopathy neuropathological change (LATE-NC) is associated with lower R2 relaxation rate: an ex-vivo MRI and pathology investigation

Limbic predominant age-related transactive response DNA binding protein 43 (TDP-43) encephalopathy neuropathological change (LATE-NC) is common in persons older than 80 years of age and is associated with cognitive decline and increased likelihood of dementia. The MRI signature of LATE-NC has not been fully determined. In this study, the association of LATE-NC with the transverse relaxation rate, R2, was investigated in a large number of community-based older adults. Cerebral hemispheres from 738 participants of the Rush Memory and Aging Project, Religious Orders Study, and Minority Aging Research Study, were imaged ex-vivo with multi-echo spin-echo MRI and underwent detailed neuropathologic examination. Voxel-wise analysis revealed a novel spatial pattern of lower R2 for higher LATE-NC stage, controlling for other neuropathologies and demographics. This pattern was consistent with the distribution of LATE-NC in gray matter, and also involved white matter providing temporo-temporal, fronto-temporal, and temporo-basal ganglia connectivity. Furthermore, analysis at different LATE-NC stages showed that R2 imaging may capture the general progression of LATE-NC, but only when TDP-43 inclusions extend beyond the amygdala.

MRI Investigation of Caudate Networks in the Normal Aging (P10-3.003)

MRI Investigation of Caudate Networks in the Normal Aging (P10-3.003)

Rare case of Marchiafava Bignami Disease (MBD)

We report a case of a 45-year-old patient with a history of severe alcoholism who presented to the emergency department an impaired unconscious and weakness with upper and lower limbs. The patient was referred to our department for an MRI investigation. MRI showed abnormalities signal in the corpus callosum. The disease is due to a deficiency of each type of vitamin B, can be the result of necrosis and demyelination of the corpus callosum and later involves the genu and splenium. Keywords: Marchiafava Bignami Disease; Corpus Callosum; MRI.

Fifteen-minute consultation: The efficient investigation of infantile and childhood epileptic encephalopathies in the era of modern genomics

The investigation of children presenting with infantile and childhood epileptic encephalopathies (ICEE) is challenging due to diverse aetiologies, overlapping phenotypes and the relatively low diagnostic yield of MRI, electroencephalography (EEG)...

First evidence of long-term effects of transcranial pulse stimulation (TPS) on the human brain

BackgroundWith the high spatial resolution and the potential to reach deep brain structures, ultrasound-based brain stimulation techniques offer new opportunities to non-invasively treat neurological and psychiatric disorders. However, little is known about long-term effects of ultrasound-based brain stimulation. Applying a longitudinal design, we comprehensively investigated neuromodulation induced by ultrasound brain stimulation to provide first sham-controlled evidence of long-term effects on the human brain and behavior.MethodsTwelve healthy participants received three sham and three verum sessions with transcranial pulse stimulation (TPS) focused on the cortical somatosensory representation of the right hand. One week before and after the sham and verum TPS applications, comprehensive structural and functional resting state MRI investigations and behavioral tests targeting tactile spatial discrimination and sensorimotor dexterity were performed.ResultsCompared to sham, global efficiency significantly increased within the cortical sensorimotor network after verum TPS, indicating an upregulation of the stimulated functional brain network. Axial diffusivity in left sensorimotor areas decreased after verum TPS, demonstrating an improved axonal status in the stimulated area.ConclusionsTPS increased the functional and structural coupling within the stimulated left primary somatosensory cortex and adjacent sensorimotor areas up to one week after the last stimulation. These findings suggest that TPS induces neuroplastic changes that go beyond the spatial and temporal stimulation settings encouraging further clinical applications.

A traumatic injury leading the lipoma of neck: a rare image.

A 58 years old male visited our hospital with the complaint of swelling over the posterior aspect of the neck after sustaining a trauma as a result of a fall of a cement slab over him 5 years back. The patient is under a combination of metoprolol and telmisartan medication for the rectification of hypertension for 10 years. The patient got admitted to the hospital for the above complaint and has undergone a histopathology report, MRI, and USG investigation. In the histopathology report, we received a single container labelled as a resected specimen of large lipoma. On the cut section, a solid, yellowish, homogenous area was identified. MRI investigation reported a lesion over the nape of the neck size measuring from 25x20x8cm in size. USG report stated a lesion over the nape of the neck and occipital region with the dimensions of the left side as 53x25mm approximately, right side as 58x31.5Â mm approximately. After both MRI and USG investigation, the patient was diagnosed with lipoma over the nape of the neck and occipital region. The patient had gone through two separate operations in a spare of 11 days. Complete excision of Excessive fibrofatty tissue size 10x15 cm lipoma was done. Flap was approximated and romovac drian no 14 placed. Closure was done with ethilon2-0 ac. PPd debridement was done with secondary suturing. Hemostasis was confirmed and Patient stable. Shifted to ward and got discharged after 1 week with prescribed medications and physiotherapy exercise.

A Clinico–radiological Correlation of Patients with Lumbar Spinal Instability

Background: A larger than normal range of motion in the spinal segment defines lumbar segmental instability, which is a sort of aberrant motion to physiologic stressors. Clinical complaints and signs such as low back ache or radiculopathy, as well as Kotilainen and Valtonen's three criteria for instability (painful catch, instability catch, and apprehension) will be correlated with an MRI investigation to determine lumbar spinal instability. Disc degeneration and facet degeneration along with soft tissues supporting spinal motion segment are important provocative factors for lumbar spine instability. The existence of lumbar instability must be identified since it can alter the treatment approach and patient prognosis.
 Objective: To evaluate clinical signs and symptoms in patients with Lumbar spinal instability, as well as to investigate radiological signs using X-rays and an MRI scan.
 Methods and Materials: In this study in which patients with history suggestive of Lumbar spinal instability will be evaluated clinically and radiologically. Patients of age group of 25-75 years will be included in this study. Clinical tests, static and dynamic Xrays and MRI scan will be studied.
 Expected Outcomes: By this study we can expect clinico–radiological co relation in patient with low back ache in lumbar spinal instability. Outcome data will be assessed on Clinico-radiological Criteria of Lumbar Instability and clinic-radiological correlation will be done.

The importance of Nuclear Magnetic Resonance (MRI) in the diagnosis of cerebral cavernomas

Introduction: Cavernomas are one of the four types of vascular malformations which develop in the central nervous system. From an imaging point of view, they are low flow small vessel malformations that cannot be seen on conventional angiography and are rarely visible on CT. They can be seen on MRI because of the para-magnetic haemoglobin break-down products within them.
 Case presentation: A 35 years old male presented at the emergency room following a tonic-clonic seizure, without urine emission. After a clinical exam, it was decided to perform a cerebral MRI with contrast substance and angiographic sequence. Clinical and imagistic results showed a superficial left temporal cavernoma, which showed signs of recent bleeding. After the surgery, the patient has no neurological deficits and is discharged afebrile and without any other symptoms. At 6 weeks after the surgery, the patients returned for neurosurgical reevaluation in perfect neurological condition, without motor deficit or intracranial hypertension.
 Conclusions: Cavernomas are angiographic cryptic vascular lesions that need an MRI investigation in order to appreciate them correctly.

Novel imaging findings in pyruvate dehydrogenase complex (PDHc) deficiency-Results from a nationwide population-based study.

The vast clinical and radiological spectrum of pyruvate dehydrogenase complex (PDHc) deficiency continues to pose challenges both in diagnostics and disease monitoring. Prompt diagnosis is important to enable early initiation of ketogenic diet. The patients were recruited from an ongoing population-based study in Sweden. All patients with a genetically confirmed diagnosis who had been investigated with an MRI of the brain were included. Repeated investigations were assessed to study the evolution of the MRI changes. Sixty-two MRI investigations had been performed in 34 patients (23 females). The genetic cause was mutations in PDHA1 in 29, PDHX and DLAT in 2 each, and PDHB in 1. The lesions were prenatal developmental in 16, prenatal clastic in 18, and postnatal clastic in 15 individuals. Leigh-like lesions with predominant involvement of globus pallidus were present in 12, while leukoencephalopathy was present in 6 and stroke-like lesions in 3 individuals. A combination of prenatal developmental and clastic lesions was present in 15 individuals. In addition, one male with PDHA1 also had postnatal clastic lesions. The most common lesions found in our study were agenesis or hypoplasia of corpus callosum, ventriculomegaly, or Leigh-like lesions. Furthermore, we describe a broad spectrum of other MRI changes that include leukoencephalopathy and stroke-like lesions. We argue that a novel important clue, suggesting the possibility of PDHc deficiency on MRI scans, is the simultaneous presence of multiple lesions on MRI that have occurred during different phases of brain development.

Composite Materials Based on Iron Oxide Nanoparticles and Polyurethane for Improving the Quality of MRI.

Polyether urethane (PU)-based magnetic composite materials, containing different types and concentrations of iron oxide nanostructures (Fe2O3 and Fe3O4), were prepared and investigated as a novel composite platform that could be explored in different applications, especially for the improvement of the image quality of MRI investigations. Firstly, the PU structure was synthetized by means of a polyaddition reaction and then hematite (Fe2O3) and magnetite (Fe3O4) nanoparticles were added to the PU matrices to prepare magnetic nanocomposites. The type and amount of iron oxide nanoparticles influenced its structural, morphological, mechanical, dielectric, and magnetic properties. Thus, the morphology and wettability of the PU nanocomposites surfaces presented different behaviours depending on the amount of the iron oxide nanoparticles embedded in the matrices. Mechanical, dielectric, and magnetic properties were enhanced in the composites’ samples when compared with pristine PU matrix. In addition, the investigation of in vitro cytocompatibility of prepared PU nanocomposites showed that these samples are good candidates for biomedical applications, with cell viability levels in the range of 80–90%. Considering all the investigations, we can conclude that the addition of magnetic particles introduced additional properties to the composite, which could significantly expand the functionality of the materials developed in this work.

Association of Hispanic/Latino background and brain structure in Hispanics/Latinos from the SOL‐INCA MRI study

AbstractBackgroundThe Hispanic Community Health Study/Study of Latinos (HCHS/SOL) is a representative, community‐based study of Hispanics and Latinos across the US that seeks to understand health disparities within this heterogeneous population. The Study of Latinos ‐ Investigation of Neurocognitive Aging MRI (SOL‐INCA MRI) is an ancillary MRI study to HCHS/SOL focused on the genetic influence and cognitive impact of age‐ and disease‐related brain measures. Brain structure undergoes substantial development and remodeling from birth through adulthood. Intracranial volume is a measure of maximum brain development, which is under substantial genetic and environmental influences, and is an independent marker of cognitive resilience. We report the influence of self‐described background on intracranial volume, brain tissue and cortical thickness measures for 1388 individuals studied to date.MethodHispanics and Latinos (ages 35.9‐85.2 years; 66% female) underwent MRI and analysis at the Imaging of Dementia and Aging (IDeA) laboratory using previously published methods. MRI outcomes of interest included supratentorial intracranial volume (TCV), image segmentation into white matter, gray matter, total brain, and regional cortical thickness. Background was categorized as Cuban, Central American, Dominican, Mexican, Puerto Rican and South American. We performed association analysis using linear regression models accounting for sex, height, background, and their interactions.ResultHeight was positively associated with TCV. Women had significantly smaller TCV than men (Table 1). TCV did not vary significantly with age. After adjusting for age, gender, height, and interactions, TCV measures varied significantly by background, and were greatest for Dominicans. Cuban’s and Mexican’s TCV measures were significantly smaller than Dominican’s (Figure 1). Cerebral gray matter volume as a residual of TCV was also significantly greater for Dominicans as compared to all other backgrounds (Table 2). Residuals of brain, gray and white matter varied significantly across backgrounds (Figure 2). Finally, cortical thickness measures varied significantly by background and brain region, being greatest for both Dominicans and Puerto Ricans (Figure 3).ConclusionBrain development results from multiple factors including gene, environment, and gene‐environment interactions. Investigating the genetic and environmental causes of the heterogeneity of brain measures in SOL‐INCA‐MRI are likely to lead to discoveries related to both brain development and possibly brain aging.

White matter association tracts underlying language and theory of mind: An investigation of 809 brains from the Human Connectome Project

Language and theory of mind (ToM) are the cognitive capacities that allow for the successful interpretation and expression of meaning. While functional MRI investigations are able to consistently localize language and ToM to specific cortical regions, diffusion MRI investigations point to an inconsistent and sometimes overlapping set of white matter tracts associated with these two cognitive domains. To further examine the white matter tracts that may underlie these domains, we use a two-tensor tractography method to investigate the white matter microstructure of 809 participants from the Human Connectome Project. 20 association white matter tracts (10 in each hemisphere) are uniquely identified by leveraging a neuroanatomist-curated automated white matter tract atlas. The fractional anisotropy (FA), mean diffusivity (MD), and number of streamlines (NoS) are measured for each white matter tract. Performance on neuropsychological assessments of semantic memory (NIH Toolbox Picture Vocabulary Test, TPVT) and emotion perception (Penn Emotion Recognition Test, PERT) are used to measure critical subcomponents of the language and ToM networks, respectively. Regression models are constructed to examine how structural measurements of left and right white matter tracts influence performance across these two assessments. We find that semantic memory performance is influenced by the number of streamlines of the left superior longitudinal fasciculus III (SLF-III), and emotion perception performance is influenced by the number of streamlines of the right SLF-III. Additionally, we find that performance on both semantic memory & emotion perception is influenced by the FA of the left arcuate fasciculus (AF). The results point to multiple, overlapping white matter tracts that underlie the cognitive domains of language and ToM. Results are discussed in terms of hemispheric dominance and concordance with prior investigations.

Author Response: Clinical, Neuroimmunologic, and CSF Investigations in First Episode Psychosis.

We appreciate the interest in our research.1 According to Pollak and colleagues,2 criteria of possible autoimmune psychosis (AP) are fulfilled if a patient has abrupt onset psychotic symptoms with at least one of the following: the presence of a tumor, movement disorder (dyskinesias, catatonia), adverse response to antipsychotics, “severe or disproportionate” cognitive dysfunction, decreased level of consciousness, unexplained seizures, and significant autonomic dysfunction.2 Fulfilment of these criteria should lead to additional tests such as EEG, MRI, and serum or CSF investigations. In our series of 105 patients with first episode of psychosis (FEP), 20% fulfilled these criteria but never developed AP.1 We confirm that 2 of 3 patients with anti-N-methyl-d-aspartate receptor (anti-NMDAR) encephalitis presenting with FEP did not fulfill any of these criteria, including catatonia, which is a complex syndrome with its own set of 12 criteria that include echolalia.3 Thus, catatonia and echolalia should not be used as interchangeable terms.