A Retrospective Study on the Status of Working Equids Admitted to an Equine Clinic in Cairo: Disease Prevalence and Associations between Physical Parameters and Outcome.

Working equids are often used to exhaustion, living and dying in conditions below minimal welfare standards. Due to their poor welfare status, euthanasia should be considered in certain conditions. The study aimed to describe the population and the disease frequency of the working equids admitted at an equine clinic in Cairo (i.e., Egypt Equine Aid (EEA)) from 2019 to 2022 and identify possible associations between physical parameters at admission and the outcome. Records of 1360 equids admitted at EEA were reviewed. The majority of the admitted equids were horses (65.6%), followed by donkeys (33%), in particular stallions (68.7%), from 1 to 15 years old (74.8%). Hospitalisation was mainly due to wounds (28.9%), orthopaedic problems (27.4%), colic (8.5%), or infectious diseases (7.4%). The majority of the equids were discharged, but 5.1% died on their own, without human intervention, and 23% were euthanised. Text mining revealed the anamnesis's most frequent words were 'accident', 'lameness', and 'wound'. In addition, owners sometimes reported using inappropriate remedies (e.g., firing) before hospitalisation. Multivariable ordinal regression analysis performed between physical parameters and the outcome (ordered based on severity: discharged, euthanasia, and dead) revealed that sex (male vs. female: OR = 1.33; p < 0.05), colour of the mucous membrane (pathological vs. physiological: OR = 1.72; p < 0.01), and capillary refill time (pathological vs. physiological: OR = 1.42; p = 0.02) increased the likelihood of a non-survival outcome. In conclusion, early euthanasia should be considered for these equids, to minimise prolonged suffering. Moreover, owners' education is recommended to guarantee minimal welfare standards to the working equids.

Postmortem findings of organ damage in novel psychoactive substances users: A comprehensive review.

INTRODUCTION: Despite the rising number of NPS-related deaths, comprehensive data on their prevalence, identification, and associated organ damage remain scarce. MATERIALS AND METHODS: A literature search was conducted. Predefined inclusion and exclusion criteria were applied, resulting in the identification of 197 articles. RESULTS: We identified 446 cases of NPS-related deaths, involving a total of 176 different substances. Synthetic opioids were the most prevalent class (34 %), followed by synthetic cannabinoids (22 %) and cathinones (21 %). Co-ingestion of NPS with other substances occurred in 77 % of cases. Macroscopic findings varied across organs, with congestion and edema most observed in the brain (23 %) and lung (56 %), respectively. DISCUSSION: The existing literature lacks comprehensive descriptions of organs subjected to autopsy and histological examination in NPS-positive subjects. Despite this limitation, our findings underscore the prominence of lung pathology. Moreover, the prevalence of normal organs in cases of acute intoxication is a significant observation. We advocate for future research to provide more detailed insights to enhance our understanding of the multifaceted landscape of NPS-related deaths.

Practical Recommendations from the Gulf Region on the Therapeutic Use of Cladribine Tablets for the Management of Relapsing Multiple Sclerosis: Impact of the Latest Real-World Evidence on Clinical Practice.

Cladribine tablets (CladT), like alemtuzumab, acts as an immune reconstitution therapy. However, CladT is administered orally (alemtuzumab is given by infusion) and without the potential for serious side effects that limit the therapeutic use of alemtuzumab in multiple sclerosis (MS). Treatment with CladT, given initially as short courses of treatment 1 year apart, provides years of freedom from MS disease activity in responders to treatment. The appearance of mild or moderate MS disease activity after the initial 2 years of treatment may prompt careful follow-up or a further course of CladT, depending on the nature of the activity and individual circumstances. The appearance of severe MS disease activity requires a switch to an alternative high-efficacy disease-modifying treatment (DMT). The accumulating data from CladT-treated people with MS in real-world studies, including those with follow-up durations extending for years beyond the initial treatment, have demonstrated long-term freedom from MS disease activity in a good proportion of patients. This clinical experience has also confirmed that treatment with CladT is generally safe and well tolerated. The best time to prescribe a high-efficacy DMT is the subject of debate, with evidence that earlier versus later use of such agents may provide more effective long-term protection from disability progression. High-efficacy DMTs have traditionally been reserved for use in people with MS and high disease activity on presentation or breakthrough disease on one or more DMTs, as per the current product labels. The latest evidence from real-world studies suggests that CladT is effective and safe in DMT-naïve patients, including those with shorter disease duration.

GLAD Scale for Ranking Welfare of Horses on Arrival after Transport to Slaughterhouses.

To date, there is no official method for measuring horse welfare after transport. This study aimed to develop a scale to classify horses into four categories: good shape; light affected; affected; down (GLAD) based on their welfare impairment measured at unloading. To this end, 15 animal-based measures (ABMs), previously recorded from 1019 horses, were scored. Weight and severity scores provided by welfare experts, alongside the number of welfare principles highlighted by the ABM, were assigned to each ABM. The welfare impairment (S) of each horse was then calculated as the weighted sum of the severity scores of the 15 ABMs. Three thresholds were also set to define the four GLAD categories; the ABM "down" (i.e., horses unable to stand and walk on arrival, also considered by the law as the indicator of the worst welfare) was used as the higher threshold, Sdown, (category D); the intermediate threshold, S2, was defined by the ABM "injuries", assumed to represent highly impaired welfare (category A); the threshold, S1, was defined assuming that significant welfare impairment starts from 20% of S2 (L category). Horses with an S value below S1 were considered physically and mentally fit (G category). Out of 1019, 43% of horses fell into category G, 48% into L, 9% into A, and 0.3% into D. Our scale could be useful for veterinarians to decide whether a horse can be slaughtered immediately (G), needs rest (L), needs attention (A), or euthanasia (D), but further validation is needed.

Dromedary camel's welfare: literature from 1980 to 2023 with a text mining and topic analysis approach.

Dromedary camels are the preferable livestock species in the arid and semi-arid regions of the world. Most of the world's camel populations are managed under a subsistence/extensive system maintained by migratory pastoralists but intensification is getting more frequent. Even though recently the welfare of camels has been receiving more attention, in many countries there are no regulations to protect their health and welfare. The objectives of this article were to explore the main research topics related to camel welfare, their distribution over time and to highlight research gaps. A literature search was performed to identify records published in English from January 1980 to March 2023 on Dromedary camel welfare via Scopus®, using "Camel welfare," "Camel behaviour," "She-camel" and "Camel management" as search words. A total of 234 records were retained for analysis after automatic and manual screening procedures. Descriptive statistics, text mining (TM) and topic analysis (TA) were performed. The result shows that even though there were fluctuations between years, records on camel welfare have increased exponentially over time. Asia was the region where most of the corresponding authors were located. The first five most frequent words were, "milk," "calv," "behaviour," "femal," and "breed," the least frequent word was "stabl." TA resulted in the five most relevant topics dealing with "Calf management and milk production," "Camel health and management system," "Female and male reproduction," "Camel behaviour and feeding," and "Camel welfare." The topics that contained the oldest records were "female and male reproduction" and "camel health and management system" (in 1980 and 1983, respectively), while the topic named "camel behaviour and feeding" had the first article published in 2000. Overall, even though topics related to camel behaviour and welfare are receiving more attention from academia, research is still needed to fully understand how to safeguard welfare in Dromedary camels.

Cats' and dogs' welfare: text mining and topics modeling analysis of the scientific literature.

Animal welfare is a field with increasing significance and has been raising huge concerns of the public and the political stage. Cats and dogs possess an important role in human life, but their welfare is not always secured from a legal aspect. This review aimed to describe the evolution and geographical distribution of "cats and dogs" and "puppies and kittens" welfare literature over the last 40 years, distinguish the main research topics studied and highlight gaps in knowledge. A search using Scopus® was performed with different search strings and predetermined filters as time range, language, and subject area. A total of 2,725 scientific literature records were retrieved but only the ones that referred to cats and dogs' welfare aspects were retained. The final 1,775 records were processed through descriptive statistics, and text mining and topic analysis procedures were performed on their titles and abstracts. The results showed that the number of studies has been increasing, especially in Europe and North America. "Shelter" was the most frequent word, followed by "behavior," "owner" and "adopt." The nine topics that emerged from the analysis were breeding, stress and housing conditions, welfare and pain assessment, public health, shelter management and euthanasia, behavioral problems, health issues and management, human-animal interaction, and owners' and veterinarians' perceptions. While stress and housing conditions, public health, and owners' and veterinarians' perceptions were the most studied topics, human-animal interaction was the least studied. This review confirmed the increasing research and interest in cats' and dogs' welfare and showed gaps in knowledge where further studies are needed.

Multicentre Observational Study of Treatment Satisfaction with Cladribine Tablets in the Management of Relapsing Multiple Sclerosis in the Arabian Gulf: The CLUE Study.

INTRODUCTION: Inconvenient administration and side effects of some disease-modifying therapies (DMTs) for relapsing multiple sclerosis (RMS) can deter adherence. We evaluated treatment satisfaction with cladribine tablets (CladT) for RMS in the Arabian Gulf. METHODS: This was a non-interventional, multicentre, prospective observational study in non-pregnant/lactating adults (aged ≥ 18 years) with RMS eligible for 1st treatment with CladT (EU labelling). The primary outcome was overall treatment satisfaction at 6 months (Treatment Satisfaction Questionnaire for Medication [TSQM]-14, v. 1.4), Global Satisfaction subscale. Secondary endpoints were TSQM-14 scores for convenience, satisfaction with side effects and satisfaction with effectiveness. Patients provided written informed consent. RESULTS: Of 63 patients screened, 58 received CladT and 55 completed the study. Mean age was 33 ± 9 years; mean weight 73 ± 17 kg; 31% male/69% female; mostly from the United Arab Emirates (52%) or Kuwait (30%). All had RMS (mean 0.9 ± 1.1 relapses in the past year), mean Expanded Disability Status Scale (EDSS) 1.4 ± 1.2; 36% were DMT-naïve. Mean [95% CI] score was high for overall treatment satisfaction (77.8 [73.0-82.6]), ease of use (87.4 [83.7-91.0]), tolerability (94.2 [91.0-97.3]) and effectiveness (76.2 [71.6-80.7]). Scores were similar irrespective of DMT history, age, gender, relapse history or EDSS. No relapses or serious treatment-emergent adverse events (TEAE) occurred. Two severe TEAE occurred (fatigue, headache) and 16% reported lymphopenia (two cases of grade 3 lymphopenia). Absolute lymphocyte counts at baseline and 6 months were 2.2 ± 0.8 × 109/L and 1.3 ± 0.3 × 109/L, respectively. CONCLUSIONS: Treatment satisfaction, ease of use, tolerability and patient-perceived effectiveness for CladT were high, irrespective of baseline demographics, disease characteristics and prior treatment.

Development of a Composite Pain Scale in Foals: A Pilot Study.

Prompt pain management is crucial in horses; however, tools to assess pain are limited. This study aimed to develop and pilot a composite scale for pain estimation in foals. The "Foal Composite Pain Scale" (FCPS) was developed based on literature and authors' expertise. The FCPS consisted of 11 facial expressions, 4 behavioural items, and 5 physical items. Thirty-five pain-free foals (Control Group) and 15 foals experiencing pain (Pain Group) were used. Foals were video-recorded at different time points: the Control Group only at inclusion (C), while the Pain Group at inclusion (T1), after an analgesic treatment (T2), and at recovery (T3). Physical items were also recorded at the same time points. Videos were scored twice by five trained observers, blinded to group and time points, to calculate inter- and intra-observer reliability of each scale item. Fleiss' kappa values ranged from moderate to almost perfect for the majority of the items, while the intraclass correlation coefficient was excellent (ICC = 0.923). The consistency of FCPS was also excellent (Cronbach's alpha = 0.842). A cut-off ≥ 7 indicated the presence of pain. The Pain Group scores were significantly higher (p < 0.001) than the Control Group and decreased over time (T1, T2 > T3; p = 0.001). Overall, FCPS seems clinically applicable to quantify pain and improve the judgment of the quality of life in foals, but it needs modifications based on these preliminary findings. Consequently, further studies on a larger sample size are needed to test the feasibility and validity of the refined FCPS.

Lethal aorto-oesophageal fistula 16 years after aortic prosthetic reconstruction: Delayed rupture as cause of death.

The development of aorto-oesophageal fistula (AOF) is a rare complication following thoracic aortic repair. Mortality is high, in most cases due to fatal haematemesis. The clinical onset is variable, occurring approximately one year after surgery. We report a case of a lethal AOF in a 58-year-old man. He underwent open vascular surgery 16 years prior to his death due to a rupture of the descending thoracic aorta. In the early 2000s, the open vascular approach was replaced by thoracic endovascular aortic repair. As a result of this approach, the number of surgical complications has reduced, with the exception of AOF.

Feasibility and safety of an enhanced recovery protocol (ERP) for upper GI surgery in elderly patients (≥ 75 years) in a high-volume surgical center.

Enhanced recovery protocols (ERP) have demonstrated their efficacy after esophagectomy and gastrectomy but little is known about their feasibility and safety in elderly patients. Patients submitted to Ivor-Lewis esophagectomy or gastrectomy for cancer between January 2016 and June 2019 were divided into three age groups: young-age group, YG (≤ 65 years, n = 130); middle-age group, MG (66-74 years, n = 101); old-age group, OG (≥ 75 years, n = 74). The groups were compared for adherence to our ERP, morbidity and mortality rates. After esophagectomy, adherence to ERP was comparable between the three groups, overall morbidity was higher in OG, without statistically significant difference, while the incidence of cardiac complications was significantly higher in OG (p = 0.02). After gastrectomy, OG presented a lower adherence to urinary catheter removal and to early mobilization. No difference in overall morbidity rate was observed (p = 0.13). The median length of stay was comparable both after esophagectomy (p = 0.075) and gastrectomy (p = 0.07). Multivariable analysis showed that age ≥ 75 years was not associated with a higher risk of ERP failure either after esophagectomy (p = 0.59) or after gastrectomy (p = 0.83). After esophagectomy, the risk of failure of the ERP program was higher for patients with ASA grade 3-4 (p = 0.03) and for those with postoperative complications (p < 0.001) while after gastrectomy only postoperative complications were associated to higher risk of ERP failure (p < 0.001). In our series, adherence to ERP protocol of patients ≥ 75 years old was similar to that of younger patients after esophagectomy and gastrectomy, without a significant increase in morbi-mortality rates.

Assessing "occult" cervical cord damage in patients with neuropsychiatric systemic lupus erythematosus using diffusion tensor MRI.

BACKGROUND: Whereas focal and diffuse brain damage on conventional MRI is seen in patients with neuropsychiatric systemic lupus erythematosus (NSLE), the spinal cord seems to be rarely involved. Diffusion tensor (DT) MRI provides information on the patterns of tissue disruption of the central nervous system, which may go undetected by conventional MRI. OBJECTIVE: To quantify the extent of otherwise "occult" injury of the cervical cord in NSLE, and to improve our understanding of its nature. SUBJECTS AND METHODS: Conventional and DT MRI scans of the cervical cord and brain were acquired from 11 patients with NSLE and 10 healthy controls. Histograms of mean diffusivity (MD) and fractional anisotropy (FA) of the cervical cord and brain were analysed. Measures of cervical cord and brain atrophy and focal lesion loads were computed. RESULTS: Only one patient had a single focal lesion of the cord whereas all had multiple brain lesions on conventional MRI scans. Cord and brain volumes did not differ between patients and controls. Mean peak height of the cervical cord MD histogram (p = 0.0001) and average brain FA (p = 0.001) were significantly lower in patients than in controls. Average cord MD was correlated with average brain MD (r = 0.69, p = 0.01) and FA (r = -0.81, p = 0.002). CONCLUSION: DT MRI shows mild and otherwise "occult" cord damage in NSLE, which might be secondary to Wallerian degeneration of long tract fibres passing trough damaged areas of the brain.

A brain magnetization transfer MRI study with a clinical follow up of about four years in patients with clinically isolated syndromes suggestive of multiple sclerosis.

Whereas it is important to gain prognostic information in patients with clinically isolated syndromes (CIS) suggestive of multiple sclerosis (MS), there is still a lack of definitive data about the significance of normal-appearing white (NAWM) and gray (NAGM) matter damage in these patients. The aim of this study was to clarify the role of magnetization transfer magnetic resonance imaging (MT MRI) in assessing "occult" damage at the earliest clinical stage of MS. Dual echo, post-contrast T1-weighted, and MT MRI were obtained from 43 CIS patients with paraclinical evidence of spatial disease dissemination within 3 months from disease onset and from 22 controls. In patients, conventional MRI was obtained after 3 and 12 months from the baseline assessment, to detect disease dissemination in time (DIT). A neurological examination was also conducted to ascertain the occurrence of relapses for an average follow up period of 1389 (range = 420-1847) days. MTR maps were derived and NAWM and NAGM MT ratio (MTR) histograms were analyzed. During the follow up, 30 patients showed MRI evidence of DIT, and 21 experienced a relapse. T2 lesion volume (LV) was significantly higher in patients with DIT than in those without (p=0.005). MTR histogram variables did not significantly differ between patients with MRI or clinical DIT. T2 LV was the only significant predictor of clinical DIT at follow-up (p=0.001). This study shows that MT MRI-detectable damage to NAWM and NAGM may not be an important feature of all patients at presentation with a CIS highly suggestive of MS and that such a damage may develop with subsequent disease evolution.

Axonal injury and overall tissue loss are not related in primary progressive multiple sclerosis.

BACKGROUND: There is an increasing body of evidence that magnetic resonance imaging-occult tissue damage is an important component of primary progressive multiple sclerosis (PPMS) pathology. Proton magnetic resonance spectroscopy (1H-MRS) can be used to measure in vivo whole-brain N-acetylaspartate (WBNAA) concentrations, the decrease of whose levels is considered a marker of neuronal-axonal injury. OBJECTIVES: To study WBNAA 1H-MRS as a tool to provide information about irreversible brain damage in PPMS and to investigate the relationship between WBNAA and other magnetic resonance imaging measures of MS disease burden, including brain atrophy. METHODS: The following magnetic resonance pulse sequences of the brain were obtained from 32 patients with PPMS and 16 age-matched healthy subjects: (1) dual-echo turbo spin-echo; (2) T1-weighted spin-echo; and (3) 1H-MRS to measure WBNAA concentration. Brain total lesion volumes were measured. Normalized brain volumes were calculated using a fully automated technique. Absolute WBNAA amounts were calculated using a phantom replacement method and were then corrected for individual subjects' brain size. RESULTS: Levels of WBNAA concentrations and normalized brain volumes were significantly lower in patients with PPMS (mean values, 10.2 mm and 1500.0 mL, respectively) than in healthy controls (mean values, 12.9 mm and 1585.2 mL). Both WBNAA concentrations and normalized brain volumes were included as independent factors in the final model of a multivariable analysis predicting the subjects' condition. No significant correlations were found between WBNAA values and normalized brain volumes, WBNAA and T2-weighted or T1-weighted lesion volumes. CONCLUSIONS: Axonal-neuronal damage in the brain of patients with PPMS seems to occur, at least partially, independently of the burden of magnetic resonance imaging-visible lesions. Whole-brain N-acetylaspartate values and normalized brain volumes were unrelated in this cohort, thereby suggesting that 1H-MRS and atrophy assessment may provide in vivo complementary information about the actual extent of brain damage in PPMS.

Diffusion-tensor magnetic resonance imaging detects normal-appearing white matter damage unrelated to short-term disease activity in patients at the earliest clinical stage of multiple sclerosis.

BACKGROUND: Diffusion-tensor (DT) magnetic resonance imaging (MRI) has the potential to elucidate some characteristics of tissue microstructure inaccessible to other MRI techniques. OBJECTIVE: To investigate whether normal-appearing brain tissue abnormalities occur in patients with multiple sclerosis at the earliest clinical stage and whether their severity is predictive of a short-term disease evolution by using DT MRI. DESIGN: Forty-five patients and 22 healthy control subjects were studied. All patients had had a clinically isolated syndrome within the 3 months preceding study enrollment and paraclinical evidence of disease dissemination in space. During a single session, dual-echo, pulsed-gradient spin-echo echo-planar, and postgadolinium T1-weighted images of the brain were obtained from each subject. In patients, dual-echo and enhanced images were obtained after 3 and 12 months, to detect MRI signs of disease dissemination in time. An on-study neurological examination was also conducted to ascertain the occurrence of clinical relapses. Mean diffusivity and fractional anisotropy maps were derived from DT images. Normal-appearing white matter (NAWM) and normal-appearing gray matter mean diffusivity and fractional anisotropy histograms were produced and analyzed. RESULTS: During the study period, 29 patients showed MRI evidence of disease dissemination in time. When compared with healthy controls, patients showed higher average NAWM mean diffusivity (P = .01), lower average NAWM mean diffusivity peak height (P < .001), and fractional anisotropy (P < .001). The DT MRI characteristics of patients did not differ between those with and those without disease dissemination in time at follow-up. CONCLUSIONS: In patients with multiple sclerosis at the earliest clinical stage, the severity of NAWM damage does not predict new lesion formation in the short term, suggesting that the "diffuse" component of tissue damage is, at least partially, independent of the "discrete," predominantly inflammatory aspects of the disease since its clinical onset.

The relation between MRI measures of inflammation and neurodegeneration in multiple sclerosis.

Gadolinium-enhanced magnetic resonance imaging (MRI) and measures of brain volume have been extensively applied in large-scale studies to assess disease activity and irreversible tissue damage in multiple sclerosis (MS). Although histopathological studies of MS demonstrated that axonal transection occurs at sites of inflammatory changes, the correlation between brain tissue loss and gadolinium enhancement was found to be either absent or poor in virtually all in vivo MRI studies. This review discusses the reasons of this "inflammation/neurodegeneration mismatch" in MS and proposes possible strategies for a better in vivo characterization of the complex pathological process of this disease.

Large-scale, multicentre, quantitative MRI study of brain and cord damage in primary progressive multiple sclerosis.

Although the mechanisms underlying the accumulation of disability in primary progressive (PP) multiple sclerosis (MS) are still unclear, a major role seems to be played by 'occult' tissue damage. We investigated whether conventional and magnetization transfer (MT) MRI may provide complementary information for the assessment of PPMS severity. Conventional and MT MRI scans from 226 PPMS patients and 84 healthy controls were collected for centralized analysis. The expanded disability status scale (EDSS) score was rated at the time of MRI acquisition. T2 lesion volume, normalized brain volume (NBV) and cervical cord cross-sectional area (CSA) were measured. Magnetization transfer ratio (MTR) histograms from whole brain tissue, normal-appearing white matter and grey matter (NAGM) were also obtained. Mean NBV, CSA and MTR histogram-derived metrics showed significant inter-centre heterogeneity. After correcting for the acquisition centre, pooled average MTR and histogram peak height values were different between PPMS patients and controls for all tissue classes (P-values between 0.03 and 0.0001). More severe brain and cord atrophy and MT MRI-detectable NAGM damage were found in patients who required walking aids than in those who did not (P-values: 0.03, 0.001 and 0.016). A composite score of NBV, CSA, whole brain and NAGM MTR histogram peak height z-scores was correlated with patients' EDSS (r = 0.37, P 0.001). Magnetization transfer MRI might provide information complementary to that given by conventional MRI when assessing PPMS severity. Sequence-related variability of measurements makes the standardization of MT MRI acquisition essential for the design of multicentre studies.

Mean diffusivity and fractional anisotropy histogram analysis of the cervical cord in MS patients.

The spinal cord is frequently involved in multiple sclerosis (MS), and cord damage may be an important contributor to disability. Diffusion tensor magnetic resonance imaging (DT-MRI) provides quantitative information about the structural and orientational features of the central nervous system. In order to assess whether diffusion tensor-derived measures of cord tissue damage are related to clinical disability, mean diffusivity (MD) and fractional anisotropy (FA) histograms from the cervical cord were acquired from a large cohort of MS patients. Diffusion-weighted sensitivity-encoded (SENSE) echo planar images of the cervical cord, and brain dual-echo and diffusion-weighted scans were acquired from 44 patients with MS and 17 healthy controls. Cord and brain MD and FA histograms were produced. An analysis of variance model, adjusting for cord volume and patient age, was used to compare cord DT-MRI parameters from controls and patients. A multivariate linear regression model was used to identify DT-MRI variables independently associated with disability. Average cervical cord FA was significantly lower in MS patients compared to controls. Cord cross-sectional area, average FA and average MD were all significantly correlated with the degree of disability (r values ranging from 0.36 to 0.51). The multivariate linear regression model retained average cord FA and average brain MD as variables independently associated with disability, with a correlation coefficient of 0.73 (P < 0.001). DT-MRI reveals a loss of cervical cord tissue structure in MS patients. The strong correlation found between a composite DT-MRI score and disability suggests that a full and accurate assessment of cervical cord damage in MS provides information that usefully contributes to an explanation of the clinical manifestations of the disease.

Short-term accrual of gray matter pathology in patients with progressive multiple sclerosis: an in vivo study using diffusion tensor MRI.

The mechanisms underlying the progressive course of multiple sclerosis (MS) are not fully understood yet. Since diffusion tensor (DT) MRI can provide quantitative estimates of both MRI-visible and MRI-occult brain damage related to MS, the present study investigated the value of DT MRI-derived measures for the assessment of the short-term accumulation of white and gray matter (GM) pathology in patients with primary progressive (PP) and secondary progressive (SP) MS. Fifty-four patients with PPMS and 22 with SPMS were studied at baseline and after a mean follow-up of 15 months. Dual-echo, T1-weighted, and DT MRI scans of the brain were acquired on both occasions. Total lesion volumes (TLV) and percentage brain volume changes (PBVC) were computed. Mean diffusivity (MD) and fractional anisotropy (FA) maps of the normal-appearing white (NAWM) and gray matter (NAGM) were produced, and histogram analysis was performed. In both patient groups, a significant increase of average lesion MD (P = 0.01) and of average NAGM MD (P = 0.007) was found at follow-up. No significant differences between PPMS and SPMS patient groups were found for the on-study changes of any MRI-derived measure. No significant correlations were found between the percentage changes of DT MRI-derived measures and those of TLV and PBVC. No significant changes of DT MRI-derived measures were observed in age-matched healthy controls over the same study period. Over a 1-year period of follow-up, DT MRI can detect tissue changes beyond the resolution of conventional MRI in the NAGM of patients with progressive MS. The accumulation of DT MRI-detectable gray matter damage does not seem to merely depend upon the concomitant increase of T2-visible lesion load and the reduction of brain volume. These observations suggest that progressive NAGM damage might yet be an additional factor leading to the accumulation of disability in progressive MS.