Radiological outcomes for endovascular treatment of posterior communicating artery aneurysms: a retrospective multicenter study of the occlusion rate.

Although several innovations in techniques and implantable devices were reported over the last decades, a consensus on the best endovascular treatment for intracranial aneurysms originating from the posterior communicating artery is still missing. This work investigates radiological outcomes of different endovascular techniques for posterior communicating artery aneurysms treatment in a retrospective multi-centric cohort. We included patients endovascularly treated for posterior communicating artery aneurysms from 2015 through 2020 in six tertiary referral hospitals. We evaluated the relationship between patients and aneurysms characteristics, baseline neurological status, radiological outcomes, and the different endovascular techniques. Overall, 250 patients were included in this study. Simple coiling was the most frequent treatment in 171 patients (68%), followed by flow-diverter stenting in 32 cases (13%). Complete occlusion was reported in 163 patients (65%), near-complete occlusion in 43 (17%), and incomplete occlusion in 44 (18%). Radiological follow-up was available for 247 (98%) patients. The occlusion rate was stable in 149 (60%), improved in 49 (19%), and worsened in 51 (21%). No significant difference in exclusion rate was seen between ruptured and unruptured aneurysms at the last follow-up (p = 0.4). Posterior communicating artery thrombosis was reported in 25 patients (9%), transient ischemic attack in 6 (2%), and in 38 patients (15%), subsequent procedures were needed due to incomplete occlusion or reperfusion. Endovascular strategies for posterior communicating artery aneurysms represent effective and relatively safe treatments. Simple coiling provides a higher immediate occlusion rate, although recanalization has been frequently reported, conversely, flow-diversion devices provide good long-term radiological outcomes.

Neuroform Atlas stent-assisted coiling of ruptured intracranial aneurysms: A multicenter study.

PURPOSE: To assess efficacy, safety and to discuss optimal medical therapy of stent-assisted coiling of ruptured intracranial aneurysms. METHODS: Ruptured intracranial aneurysms treated with stent-assisted coiling in eight different institutions were retrospectively reviewed. Medical treatment regimens varied among the centers, mainly regarding heparin administration and post-procedural single or double antiplatelet therapy. Clinical and angiographic results, including complications and outcomes were analyzed and related to the different therapies. RESULTS: Sixty-one consecutive patients (male/female 23/38), aged 59.1 years (36-86) underwent stent-assisted coiling for ruptured intracranial aneurysm without antiplatelet pre-medication. Intravenous acetylsalicylic acid (ASA) 500mg was administered to all patients immediately after stent deployment. At the same time heparin was given as bolus in 15 patients (24.6%) as part of local protocol. Intravenous glycoprotein 2b/3a inhibitors (antiGP2b3a) were used as bail-out therapy for stent thrombosis. Stent thrombosis occurred in 22 patients (36.1%), of which 4 (6.5%) lead to incomplete and 18 (29.6) to complete occlusion of the stent. Heparin administration had no effect on thrombosis rate. Thrombosis resolution occurred in all cases with intravenous antiGP2b3a (7 tirofiban, 15 abciximab), without increasing overall complication rate. Single antiplatelet therapy with ASA (28 patients, 45.9%) or double antiplatelet therapy including ASA and clopidogrel (33 patients, 54.1%) were administered after procedure, depending on local protocols and on neurointerventionists' experience. Overall complication rate, including ischemia and hemorrhage was higher in patients in which only ASA was administered (21.4% vs. 12.1%). No late stent thrombosis was seen, regardless of whether a single or double antiplatelet regimen was used. Nevertheless, the small sample size suggests caution in interpreting these results. Moreover, a possible bias may arise from the decision whether to modify the maintenance therapy or not depending on the severity of the intracranial hemorrhage in a case-by-case assessment. At three months, 34 out of 38 patients with HH grade 1-2 (89.4%), and 11 out of 23 with Hunt-Hess grade of 3-4 (47.8%) were independent (Modified Ranking Scale 0-2). CONCLUSION: Stent assisted coiling of ruptured intracranial aneurysms is a feasible option when simple coiling is not possible. Optimal medical treatment is still controversial because balance between hemorrhagic and ischemic risks is difficult to evaluate. In our series, heparin bolus had no effect on subsequent stent thrombosis. In all cases peri-operative stent thrombosis was successfully managed using bail-out intravenous antiGP2b3a, which did not increase post-procedural hemorrhage rates. A non-significant trend towards increased complications rate was noticed in patients treated with single antiplatelet therapy versus double antiplatelet therapy.

Utility of 3D rotational angiography road map in flow diverter deployment in a distal dissecting MCA aneurysm.

Distal, dissecting, middle cerebral artery (MCA) aneurysms are changing surgically and endovascularly. Endovascular treatment requires flow diverter stenting. A good vessel visualization is crucial for safe navigation. Three-dimensional rotational digital subtraction angiography (3D-DSA) is used routinely in diagnostic imaging. The utilization of the 3D-DSA road map in vessel navigation and stent deployment is novel. An illustrative video of a distal, dissecting left MCA aneurysm treated with flow diverter stenting is presented. The technical issues were distal location, dissecting nature with double lumen, proximal stenosis, and vessel curves. The 3D-DSA road map helped to enhance visualization with a safer procedure.The video can be found here: https://youtu.be/sS3o1Z0P8WE.

Complete embolization of jugular paragangliomas by direct puncture. Technical note.

Objective: Intra-arterial embolization of jugular paragangliomas is an established endovascular technique. Intratumoral embolization by direct puncture has been proposed, prior to surgical treatment or radiosurgery to reduce the risk of cranial nerve deficits. Methods: We examined the technical aspects of two patients with jugular paragangliomas embolized with liquid embolic agent by direct puncture of the lesion, as sole treatment. Results: Two patients with jugular paragangliomas presented with lower cranial nerve deficits. The first patient showed an extended lesion (55-mm) and was treated with partial intra-arterial embolization plus direct puncture and injection of Squid 18 and a second staged embolization by direct puncture and filling of the remainder of the lesion. The second patient with a smaller jugular paraganglioma (33-mm) was treated by single embolization by direct puncture of the tumor and injection of Squid 12 and Squid 18 obtaining complete filling of the lesion. No procedural complications were observed. Both patients showed no residual and initial improvement of the neurological deficits. Conclusion: The intratumoral embolization by direct puncture of jugular paragangliomas, under accurate radiological control is a safe procedure, and complete exclusion of the lesion can be obtained in selected cases. A staged particle embolization of the lesion by direct puncture can be proposed for large lesions. Only further studies with larger series and long-term follow-up will be able to define, if this strategy can be curative avoiding additional surgical or radio-surgical treatment.

Italian multicenter experience with flow-diverter devices for intracranial unruptured aneurysm treatment with periprocedural complications--a retrospective data analysis.

INTRODUCTION: We report the experiences of 25 Italian centers, analyzing intra- and periprocedural complications of endovascular treatment of intracranial aneurysms using Silk (Balt Extrusion, Montmorency, France) and pipeline embolization devices (EV3 Inc, Irvine California). METHODS: Two hundred seventy-three patients with 295 cerebral aneurysms, enrolled in 25 centers in Italy and treated with the new flow-diverter devices, were evaluated; 142 patients were treated with Silk and 130 with pipeline (in one case, both devices were used). In 14 (5.2 %) cases devices were used with coils. Aneurysm size was >15 mm in 46.9 %, 5-15 mm in 42.2 %, and <5 mm in 10.8 %. Aneurysm locations were supraclinoid internal carotid artery (ICA) in 163 cases (55.2 %), cavernous ICA in 76 (25.7 %), middle cerebral artery in 11 (3.7 %), PCoA in 6 (2 %), and ACoA in 2 (0.7 %); the vertebrobasilar system accounted for 32 cases (10.8 %) and PCA in 5 (1.7 %). RESULTS: Technical adverse events occurred with 59 patients (21.6 %); 5 patients died after ischemic events, 10 to hemorrhagic complications, and 1 from external ventricular drain positioning. At 1 month, morbidity and mortality rates were 3.7 % and 5.9 %, respectively CONCLUSION: Our retrospective study confirms that morbidity and mortality rates in treatment with FDD of unruptured wide-neck or untreatable cerebral aneurysms do not differ from those reported in the largest series.

Surgical management of large scalp infantile hemangioma in 30-month-old infant.

Infantile Hemangiomas (IH) are the most common benign tumor of infancy, occurring in over 10% of newborns. The head and neck is the most frequently affected area (60%), and the scalp is a typical site for such large lesions. Scalp-IHs are usually focal lesions that can be both disfiguring and may lead to complications such as ulceration and bleeding. We describe a case of a 30-months old female who presented a large scalp-IH at birth that rapidly grew in the first year of life. Topical and systemic treatments (with timolol ointment and oral propranolol, respectively) were not effective in reducing dimensions of the hemangioma. After vascular imaging study, the patient underwent surgical resection of the IH and primary closure with excellent cosmetic outcome. When medical therapy is ineffective or cosmetic and functional integrity is threatened, early surgery allows to completely removing large scalp-IHs, with good cosmetic results.

Successful treatment of ruptured multiple fusiform middle cerebral artery aneurysms with Silk Vista Baby flow diverter in a 10-month-old infant.

We report the successful treatment of multiple ruptured fusiform middle cerebral artery (MCA) aneurysms in a 10-month-old girl. This previously healthy infant presented with subarachnoid hemorrhage and was found to have multiple irregular dilatations of the superior division branch of the right MCA. Cerebral angiography was performed and confirmed the presence of multiple fusiform aneurysms of the MCA. After discussion with the multidisciplinary team, it was decided to treat the aneurysms with a endovascular approach, using a flow diverter. Microsurgical clipping was deemed risky because of the high likelihood of parent artery occlusion, and expectant management was also considered inappropriate because of the risk of rebleeding. Dual antiplatelet therapy was started, and a flow diverter was successfully delivered in the superior division branch of the right MCA. The postoperative course was uneventful, MRI at 12 months did not show any sign of recurrence, and at 3 years of age the patient had a normal neurological examination.

Non-traumatic Myositis Ossificans as Unusual Cause of Neck Pain During COVID-19 Pandemic: a Case Report.

Myositis ossificans circumscripta (MOC) is a benign disease characterized by localized heterotopic bone formation within muscles or soft tissue, usually interesting great muscles of extremities. We report a rare case of unusual location in the neck not associated with previous trauma, mimicking a solid tumor, with well-documented diagnostic imaging features. During COVID-19 pandemic outbreak in Italy, in May 2020, a 14-year-old boy developed a progressive and persistent neck pain on the right side, without known history of trauma. Initial therapy with non-steroid anti-inflammatory drugs and physiokinetic therapy gave only a slight improvement. A neck ultrasound showed an inhomogeneous right neck mass, with posterior shadowing due to calcifications. Computed tomography and magnetic resonance imaging confirmed a huge right neck mass, located in the paravertebral space with peripheral calcifications and mild central contrast enhancement. After surgical excision of the lesion, pathology revealed the presence of muscular tissue mixed with fibroblastic/myofibroblastic proliferation and ossification areas consistent with myositis ossificans. A careful analysis of clinical and radiological features is very important to manage young patients showing progressive pain and swelling of the neck, since MOC can mimic soft tissue or bone tumors, and it should be suspected even in the absence of a known history of trauma.

Radiologic Imaging of the In Vivo Position of the New Supraglottic Airway Device Spritztube® in an Adult Patient-A Case Report.

Spritztube® is a new supraglottic airway device that allows either extraglottic ventilation or orotracheal intubation with the same device. The aim of the present report is to provide the first radiologic images of the Spritztube in situ in a living human and to assess the depth of insertion and its anatomical relationships in vivo. We present the case of a 55-year-old man who was admitted to our centre to perform an interventional neuroradiological procedure. We obtained and analysed radiologic images of the head and neck of an adult patient to ascertain the position of the cuffs of the Spritztube relative to different anatomic structures. The insertion and depth of the device, correct tip positioning, effects of the distal and proximal cuffs on adjacent soft tissues, and the position of the pharyngeal cuff from the cranial to the hyoid bone were evaluated. Our report shows that Spritztube could be helpful in maintaining an adequate airway during radiologic procedures.

Isolated cerebellar progressive multifocal leukoencephalopathy after allogeneic bone marrow transplantation: focus on imaging.

INTRODUCTION: Progressive multifocal leukoencephalopathy (PML) is caused by JC virus opportunistic infection in the setting of immunodeficiency. Typical imaging features are multifocal and asymmetric lesions within supratentorial subcortical white matter in parieto-occipital regions. CASE DESCRIPTION: A 47-year-old patient experienced a relapse of acute myeloid leukemia 21 months after hematopoietic stem cell transplantation. He also had visual impairment and magnetic resonance imaging showed an isolated cerebellar lesion without mass effect or enhancement. Common opportunistic infections and leukemic central nervous system involvement were excluded by cerebrospinal fluid (CSF) analysis. Given the worsening clinical and radiologic scenario, PML was suspected, and CSF protein chain reaction analysis was positive for JC virus. CONCLUSIONS: Given its potential curability, PML should be thoroughly investigated in patients with hematologic neoplasms and atypical isolated cerebellar presentation.

Republished: Successful treatment of ruptured multiple fusiform middle cerebral artery aneurysms with silk vista baby flow diverter in a 10-months-old infant.

We report the successful treatment of multiple ruptured fusiform middle cerebral artery (MCA) aneurysms in a 10-month-old girl. This previously healthy infant presented with subarachnoid haemorrhage and was found to have multiple irregular dilatations of the superior division branch of the right MCA. Cerebral angiography was performed and confirmed the presence of multiple fusiform aneurysms of the MCA. After multidisciplinary team discussion, it was decided to treat the aneurysms with endovascular approach, using a flow-diverter. Microsurgical clipping was deemed risky because of the high likelihood of parent artery occlusion and expectant management was also considered inappropriate because of the risk of re-bleeding. Dual antiplatelet therapy was started, and a flow-diverter was successfully delivered in the superior division branch of the right MCA. The post-operative course was uneventful, MRI at 12 months did not show any sign of recurrence and at 3 years of age the patient had a normal neurological examination.

Gadolinium-based contrast media exposure and the possible risk of subclinical kidney damage: a pilot study.

PURPOSE: We performed a pilot study to evaluate the feasibility of future research about the presence of subclinical kidney damage after Gadolinium-based contrast media exposure. The future study aims to understand which are the behaviors of two markers of kidney damage, such as urinary NephroCheck (NC) and/or neutrophil gelatinase-associated lipocalin (NGAL). Specifically, after GBCM exposure, NC urinary detection should identify proximal tubule damage while NGAL urinary detection should be related to distal tubule damage. METHODS: We performed a pilot study in patients who had Gadolinium exposure. The feasibility of future study is reached when at least 90% of candidates completed the pilot study. In each patient, we tested urinary NC and NGAL levels 24 h before magnetic resonance imaging (MRI) and 12-24 h after the exposure. Furthermore, we evaluated the administration of other nephrotoxic agents, the presence of comorbidity, and kidney function by S-creatinine and urine protein before the MRI. RESULTS: We enrolled 35 candidates of whom 33 patients completed all study procedures. Our population had a mean age of 60.7 ± 14.8 years with normal kidney function with a median S-creatinine equal to 0.7 mg/dl (Interquartile range [IQR] 0.6-0.91). Urinary NC levels increased from 0.21 ng2/ml2 (IQR 0.11-0.4) before MRI to 0.34 ng2/ml2 (IQR 0.16-0.86) (p = 0.005). Conversely, we did not appreciate any significant modification in urinary NGAL (p = 0.53). CONCLUSION: Our pilot study seems adequate in terms of feasibility and encourages us to focus our future research on renal proximal tubule, as the principal site of subclinical kidney damage after Gadolinium exposure.

Long-term follow-up of the Derivo® Embolization Device (DED®) for intracranial aneurysms: the Italian Multicentric Registry.

BACKGROUND: The flow-diverter devices (FDDs) safety and effectiveness have been demonstrated by large series and meta-analyses. Due to the high occlusion rates and the acceptable morbidity rates of FDDs, the indications for their use are continuously expanding. We presented our Italian multicentric experience using the second generation of DERIVO® Embolization Device (DED®; Acandis, Pforzheim, Germany) to cure cerebral aneurysms, evaluating both middle and long-term safety and efficacy of this device. METHODS: Between July 2016 and September 2017 we collected 109 consecutive aneurysms in 108 patients treated using DED® during 109 endovascular procedures in 34 Italian centers (100/109 aneurysms were unruptured, 9/109 were ruptured). The collected data included patient demographics, aneurysm location and characteristics, baseline angiography, adverse event and serious adverse event information, morbidity and mortality rates, and pre- and post-treatment modified Rankin Scale scores. Midterm and long-term clinical, angiographic and cross-sectional CT/MR follow-up were recorded and collected until December 2018. RESULTS: In 2/109 cases, DED® placement was classified as technical failures. The overall mortality and morbidity rates were respectively 6.5% and 5.5%. Overall DERIVO® related mortality and morbidity rates were respectively 0% and 4.6% (5 out of 108 patients). Midterm neuroimaging follow-up showed the complete or nearly complete occlusion of the aneurysm in 90% cases, which became 93% at long-term follow-up. Aneurysmal sac shrinking was observed in 65% of assessable aneurysms. CONCLUSIONS: Our multicentric experience using DED® for endovascular treatment of unruptured and ruptured aneurysms showed a high safety and efficacy profile, substantially equivalent or better compared to the other FDDs.

Spinal 'flip-flop' effect in anorexia nervosa: A case report.

Anorexia nervosa is a psychiatric eating disorder related to malnutrition and consequent altered metabolism. A 48-year-old female with a history of anorexia in the last 2 years referred to our hospital with spinal pain. She underwent spinal X-ray and magnetic resonance imaging (MRI) showing multiple vertebral collapses in dorsal and lumbar spine with inversion of normal bone marrow and soft tissue signal in T1-weighted and STIR images. We describe this case of spinal 'flip-flop' phenomenon, underlining how what seems a technical failure is actually a specific imaging pattern related to the clinical context.

Subclinical Contrast-Induced Acute Kidney Injury in Patients Undergoing Cerebral Computed Tomography.

INTRODUCTION: The nephrotoxicity of modern contrast media remains controversial. Novel biomarkers of kidney damage may help in identifying a subclinical structural renal injury not revealed by widely used markers of kidney function. OBJECTIVE: The aim of this study was to investigate clinical (contrast-induced acute kidney injury [CI-AKI]) and subclinical CI-AKI (SCI-AKI) after intra-arterial administration of Iodixanol and Iopamidol in patients with an estimated glomerular filtration rate (eGFR) ≥60 mL/min/1.73 m2. METHODS: This is a prospective observational monocentric study. Urinary sample was collected at 4-8 h after contrast medium exposure to measure neutrophil gelatinase associated lipocalin (NGAL) and the product tissue inhibitor of metalloproteinase-2 and insulin-like growth factor-binding protein 7 ([TIMP-2] × [IGFBP7]), while blood samples were collected at 24 and 48 h after exposure to measure serum creatinine. RESULTS: One hundred patients were enrolled, of whom 53 were exposed to Iodixanol and 47 to Iopamidol. Patients in Iodixanol and Iopamidol groups were comparable in terms of demographics, pre-procedural and procedural data. No patient developed CI-AKI according KDIGO criteria, while 13 patients reported SCI-AKI after exposure to iodine-based medium contrast (3 patients in Iodixanol group and 10 patients in Iopamidol group), defined by positive results of NGAL and/or [TIMP-2] × [IGFBP7]. A positive correlation was found between NGAL and [TIMP-2] × [IGFBP7] in the analysed population (Spearman's rho 0.49, p < 0.001). In logistic regression analysis, Iopamidol exposure showed higher risk for SCI-AKI compared to Iodixanol (OR 4.5 [95% CI 1.16-17.52], p = 0.030), even after controlling for eGFR and volume of contrast medium used. CONCLUSIONS: This study showed that intra-arterial modern contrast media administration may have a nephrotoxic effect in a population without pre-existing chronic kidney disease. Further investigations on larger scale are warranted to confirm if Iopamidol exposed patients to increased risk of SCI-AKI compared to Iodixanol.

Progressive gray matter damage in patients with relapsing-remitting multiple sclerosis: a longitudinal diffusion tensor magnetic resonance imaging study.

BACKGROUND: Diffusion tensor magnetic resonance imaging (DT MRI) has the potential to provide in vivo information about tissue microstructure. In multiple sclerosis (MS), DT MRI has disclosed the presence of occult structural damage in the normal-appearing brain tissues. OBJECTIVE: To investigate whether DT MRI is sensitive to longitudinal changes of brain damage that may occur beyond the resolution of T2-weighted images in patients with relapsing-remitting MS. DESIGN: Twenty-six untreated patients with relapsing-remitting MS were followed up for 18 months. Dual-echo, DT and postcontrast T1-weighted MRIs of the brain were obtained at baseline and then every 3 months. Mean diffusivity (D) histograms of normal-appearing gray (GM) and white matter were produced. Total T2-hyperintense and T1-hypointense lesion volumes; normalized whole brain tissue, GM, and white matter volumes; percentage brain volume change between the study entry and exit images; average lesion D; and fractional anisotropy were also calculated. RESULTS: During the study period, a significant decrease of normalized whole brain tissue, average lesion fractional anisotropy and normal-appearing GM D histogram peak height, and a significant increase of average normal-appearing GM D and T2-hyperintense lesion volumes were observed. Changes of normal-appearing GM diffusivity were independent of the concomitant changes of normalized whole brain tissue and GM volumes. CONCLUSIONS: The DT MRI findings show progressive microstructural changes in the normal-appearing GM of patients with untreated relapsing-remitting MS. Such changes do not reflect a concomitant development of brain atrophy and confirm the importance of GM pathology in MS.

European study on intravenous immunoglobulin in multiple sclerosis: results of magnetization transfer magnetic resonance imaging analysis.

BACKGROUND: Magnetization transfer magnetic resonance imaging (MT MRI) can provide in vivo markers reflecting the severity of multiple sclerosis-related brain damage occurring within and outside T2-visible lesions. OBJECTIVE: To investigate the effect of intravenous immunoglobulin (IVIG) treatment on the accumulation of brain damage in patients with secondary progressive multiple sclerosis (SPMS), measured using MT MRI.Design, Patients, and Intervention Seventy patients with SPMS participating in the European, multicenter, randomized, double-blind, placebo-controlled trial of IVIG in SPMS underwent brain T2-weighted and MT MRI at baseline and after 12 and 24 months. The MT MRI scans were post-processed and analyzed to obtain MT ratio values from T2-visible lesions and MT ratio histograms from the normal-appearing brain tissue (NABT). RESULTS: At baseline, a significant difference was found for NABT MT ratio histogram peak height (P =.003) between treated patients and patients receiving placebo. No significant differences between treated patients and those receiving placebo were found for any of the considered MT MRI-derived metrics in terms of treatment x time interaction. Nevertheless, over the 24-month period, the placebo patients experienced a 6.75% reduction of the NABT MT ratio histogram peak height, whereas treated patients experienced only a 0.92% reduction of the NABT MT ratio histogram peak height. CONCLUSIONS: This study did not show any statistically significant effect of IVIG on MT MRI quantities. Nevertheless, the markedly different percentage change of the NABT MT ratio histogram peak height over time between patients receiving placebo and treated patients suggests a possible role of IVIG treatment in preventing the loss of "truly" normal brain tissue in SPMS patients.

Assessment of normal-appearing white and gray matter in patients with primary progressive multiple sclerosis: a diffusion-tensor magnetic resonance imaging study.

BACKGROUND: Diffusion-tensor magnetic resonance imaging is sensitive to the more destructive aspects of multiple sclerosis (MS) evolution occurring outside and within T2-visible lesions and, as a consequence, holds promise for providing a more complete picture of primary progressive (PP) MS-related tissue damage than conventional magnetic resonance imaging. OBJECTIVE: To improve our understanding of PPMS by assessing the extent of occult pathological features in the normal-appearing white and gray matter of the brain using diffusion-tensor magnetic resonance imaging. METHODS: Ninety-six patients with PPMS, 47 patients with secondary progressive (SP) MS, and 44 healthy control subjects were studied. T2-hyperintense and T1-hypointense lesion volumes were calculated, and the volume of the whole brain tissue was measured. Diffusion-tensor magnetic resonance imaging scans were postprocessed and analyzed to obtain the mean diffusivity and fractional anisotropy histograms from the brain and from the normal-appearing white and gray matter in isolation. RESULTS: The mean T2-hyperintense and T1-hypointense lesion volumes were lower in patients with PPMS than in patients with SPMS, while the mean absolute brain volumes were similar in the 2 groups. The average lesion diffusivity was significantly higher in patients with SPMS than in patients with PPMS (P<.001). Histogram-derived metrics of the brain tissue and normal-appearing white and gray matter were significantly different between patients with PPMS and healthy subjects (range, P =.004 to <.001). Average diffusivity values were significantly higher in patients with SPMS than in patients with PPMS for all the tissues studied (range, P =.001 to <.001). Fractional anisotropy histogram-derived quantities did not significantly differ between the 2 patient groups (range, P =.94 to.03). CONCLUSION: This study confirms that, in patients with PPMS, normal-appearing white and gray matter are not spared by disease-related pathological processes, although they are affected to a lesser degree than in patients with SPMS.