Single center study of 53 consecutive patients with pituitary stalk lesions.

BACKGROUND: The etiological spectrum of pituitary stalk lesions (PSL) is wide and yet specific compared to the other diseases of the sellar and suprasellar region. Because of the pituitary stalk's (PS) critical location and role, biopsies of these lesions are rarely performed, and their underlying pathology is often a conundrum for clinicians. A pituitary MRI in association with a clinical context can facilitate their diagnosis. AIM: To present the various causes of PSL-their clinical, hormonal, histopathological, and MRI characteristics in order to gain better insight into this pathology. METHOD: A retrospective observational study consisting of 53 consecutive patients with PSL of the mean age 32 ± 4.2 years (range 6-67), conducted at the Department for Neuroendocrinology, Clinical Center of Serbia 2010-2018. RESULTS: Congenital malformations were the most common cause of PSL in 25 of 53 patients (47.1%), followed by inflammatory (9/53; 16.9%) and neoplastic lesions (9/53; 16.9%). The exact cause of PSL was established in 31 (58.4%) patients, of whom 23 were with congenital PS abnormalities and 8 with histopathology of PSL (7 neoplastic and 1 Langerhans Cell Hystiocytosis). A probable diagnosis of PSL was stated in 12 patients (22.6%): 6 with lymphocytic panhypophysitis, while Rathke cleft cyst, tuberculosis, dissemination of malignancy in PS were each diagnosed in 2 patients. In 10 patients (18.8%), the etiology of PSL remained unknown. CONCLUSION: Due to the inability of establishing an exact diagnosis, the management and prognosis of PSL are difficult in many patients. By presenting a wide array of causes implicated in this condition, we believe that our study can aid clinicians in the challenging cases of this pathology.

Differentiation between progression and pseudoprogresion by arterial spin labeling MRI in patients with glioblastoma multiforme.

PURPOSE: To compare arterial spin labeling (ASL) perfusion technique with the clinically established dynamic susceptibility contrast-enhanced (DSC) perfusion weighted-imaging (PWI), and to determine its value in routine MRI evaluation of disease progression in patients with glioblastoma multiforme (GBM). METHODS: A prospective intraindividual study was performed in 31 patients with histologically proven GBM who had clinical and/or radiological deterioration after treatment, including surgery, radiotherapy and therapy with temozolomide. Conventional brain protocol with ASL and DSC techniques was performed on 3T MRI unit. Cerebral blood flow (CBF) and cerebral blood volume (CBV) maps were analyzed by means of regions of interest (ROI). Each ROI average value was normalized to the contralateral normal brain parenchyma ROI value. Neuroradiologists analyzed CBF and CBV maps separately, and classified patients into progression or pseudoprogression group. Radiological diagnosis was confirmed by clinical-radiological follow-up for at least three months after patient deterioration. RESULTS: High linear correlation existed between DSC-PWI and ASL in the tumor ROI (r=0.733; p<0.001). 92% of ASL CBF maps were informative. ASL detected all lesions as well as DSC MRI. Both techniques provided perfusion values closely correlated. CONCLUSION: ASL allows distinction between GBM progression and pseudoprogression, and it can be used as reliable alternative to DSC-PWI.

A Survival Analysis with Identification of Prognostic Factors in a Series of 110 Patients with Newly Diagnosed Glioblastoma Before and After Introduction of the Stupp Regimen: A Single-Center Observational Study.

BACKGROUND: Current treatment protocol for glioblastoma multiforme (GBM) is based on maximal safe resection followed by the Stupp protocol. In Serbia, temozolomide was introduced as adjuvant therapy in 2011. The aims of this study were to confirm the safety and efficacy on overall and progression-free survival of the Stupp protocol and evaluate the influence of prognostic factors in one of the largest series of patients with GBM treated over a 2-year period. METHODS: Between January 2010 and December 2012, 110 patients with newly diagnosed GBM underwent surgical removal at the Neurooncology Department of the Clinic Center of Serbia. Patients were divided into 2 groups according to postoperative treatment. Group A (n = 24 patients), treated before January 2011, received adjuvant standard radiation therapy and carmustine (bis-chloroethyl-nitrosourea), and group B (n = 86 patients), treated after January 2011, received postoperative treatment according to the Stupp protocol. RESULTS: The Stupp protocol had a significant favorable impact on overall survival at 1-year follow-up (79.1% in group B vs. 62.5% in group A; P = 0.016); no differences were noted in regard to progression-free survival. Multivariate analysis identified younger age and gross total resection of tumor as positive prognostic factors. CONCLUSIONS: Adoption of the Stupp protocol had a favorable impact on overall, but not on progression-free, survival rate. Wider surgical resection involving the peritumoral brain zone, as confirmed by univariate and multivariate analysis, represents the most favorable prognostic factor.

Myopathy, muscle atrophy and tongue lipid composition in MuSK myasthenia gravis.

Myasthenia gravis (MG) associated with anti-muscle-specific tyrosine kinase (MuSK) antibodies differs in many aspects from typical presentation of acetylcholine receptor (AChR)-positive MG. Myopathy and muscle atrophy are observed in MuSK-positive MG patients, unlike AChR-positive patients with MG. That is why the aim of this study was to assess the presence of myopathy and muscle atrophy as well as the tongue lipid composition in our cohort of MuSK-positive MG patients. Clinical examination, electromyography (EMG) and proton magnetic resonance spectroscopy were performed in 31 MuSK-positive and 28 AChR-positive MG patients. Myopathic EMG was more frequent in MuSK compared to AChR MG patients. In AChR MG patients, myopathic EMG in facial muscles was more frequent after long-term corticosteroid treatment, which was not the case with MuSK-positive MG patients. Facial and/or tongue muscle atrophy was registered in 23 % of MuSK MG patients. Longer disease duration was observed in patients with clinical signs of tongue and/or facial muscle atrophy compared to those with normal tongue muscle. Intramyocellular lipid deposition in the tongue was present in 85.2 % of MuSK and 20 % of AChR MG patients. Female MuSK MG patients had more frequently electrophysiological signs of myopathy on the facial muscles and signs of intramyocellular lipid deposition in the tongue, compared to male patients with MuSK-positive MG. Myopathy, muscle atrophy and intramyocellular lipid deposition in the tongue are more frequent in MuSK-positive compared to AChR-positive MG patients.

Diagnostic value of combined magnetic resonance imaging examination of brachial plexus and electrophysiological studies in multifocal motor neuropathy.

BACKGROUND/AIM: Multifocal motor neuropathy (MMN) is an immune-mediated disorder characterised by slowly progressive asymetrical weakness of limbs without sensory loss. The objective of this study was to investigate the involvement of brachial plexus using combined cervical magnetic stimulation and magnetic resonance imaging (MRI) of plexus brachialis in patients with MMN. We payed special attention to the nerve roots forming nerves inervating weak muscles, but without detectable conduction block (CB) using conventional nerve conduction studies. METHODS: Nine patients with proven MMN were included in the study. In all of them MRI of the cervical spine and brachial plexus was performed using a Siemens Avanto 1.5 T unit, applying T1 and turbo spin-echo T1 sequence, axial turbo spin-echo T2 sequence and a coronal fat-saturated turbo spin-echo T2 sequence. RESULTS: In all the patients severe asymmetric distal weakness of muscles inervated by radial, ulnar, median and peroneal nerves was observed and the most striking presentation was bilateral wrist and finger drop. Three of them had additional proximal weakness of muscles inervated by axillar and femoral nerves. The majority of the patients had slightly increased cerebrospinal fluid (CSF) protein content. Six of the patients had positive serum polyclonal IgM anti-GM1 antibodies. Electromyoneurography (EMG) showed neurogenic changes, the most severe in distal muscles inervated by radial nerves. All the patients had persistent partial CBs outside the usual sites of nerve compression in radial, ulnar, median and peroneal nerves. In three of the patients cervical magnetic stimulation suggested proximal CBs between cervical root emergence and Erb's point (prolonged motor root conduction time). In all the patients T2-weighted MRI revealed increased signal intensity in at least one cervical root, truncus or fasciculus of brachial plexus. CONCLUSION: We found clinical correlation between muscle weakness, prolonged motor root conduction time and MRI abnormalities of the brachial plexus, which was of the greatest importance in the nerves without CB inervating weak muscles.

Proton magnetic resonance spectroscopy and apparent diffusion coefficient in evaluation of solid brain lesions.

BACKGROUND/AIM: Advanced magnetic resonance techniques can provide insight in physiological changes within pathological canges and contribute to better distinquishing between different tumor types and their discrimination from non-neoplastic lesions. The aim of this study was to evaluate the role of proton magnetic resonance spectroscopy (1H-MRS) and apparent diffusion coefficients (ADC) in distinguishing intracranial glial tumors from tumor like nonneoplastic lesions, as well as for differentiating high- from low-grade gliomas. METHODS: This retrospective study included 47 patients with solid brain lesions (25 nonneoplastic, 14 low-grade and 8 anaplastic glial tumors). In all patients 1H-MRS (at a TE of 135 ms and 30 ms) and diffusion-weighted imaging (DWI) were performed. The choline to creatine (Cho/Cr), choline to N-acetyl aspartate (Cho/NAA), N-acetyl aspartate to creatine (NAA/Cr) and myoinositol to creatine (mIn/Cr) ratios and the apparent diffusion coefficient (ADC) were determined. RESULTS: The Cho/Cr ratio was significantly higher in glial tumors grade II than in non-neoplastic lesions (p = 0.008) and in glial tumors grade III than in non-neoplastic lesions (p = 0.001). The Cho/NAA ratio was significantly higher in glial tumors grade II than in non-neoplastic lesions (p = 0.037). AADC/ADC between glial tumors grade II and glial tumors grade III showed a statistical significance (p = 0.023). CONCLUSION: Our study showed that 1H-MRS and apparent diffusion coefficients can help in evaluation and differentiation of solid brain lesions.

Brain iron MRI: a biomarker for amyotrophic lateral sclerosis.

PURPOSE: To evaluate the usefulness of MRI detection of hypointensity areas (iron deposits) in the brain using a dedicated MRI technique in patients with ALS in establishing this sign as a potential surrogate biomarker that correlates with the severity of disease. MATERIALS AND METHODS: Forty-six ALS patients and 26 age-matched controls were examined by MRI. The ALS Functional Rating Scale (ALSFRS) score was determined before the first MRI examination. The sub-set of 25 ALS patients was re-examined around 6 months after the first MRI examination. The MRI examination consisted of routine T1W, T2W, and FLAIR sequences with the addition of a thin slice heavily T2* weighted sequence to accentuate magnetic susceptibility artifacts. RESULTS: T2*W sequence is superior to any other MRI sequence in detecting hypointensities in the brain of ALS patients. Hypointensities were found only in the precentral gyruses gray matter (PGGM) and were detected in 42 patients. The extent of hypointensities was measured and scored (0-3) and correlated with ALSFRS (r = -0.545). Twenty-five patients were re-examined 6 months later, and the majority of them showed the shift toward higher MRI scores. No control subjects had hypointensities in PGGM. CONCLUSION: The detection of hypointensities in PGGM appears to be a very promising surrogate MRI biomarker for ALS due to its simplicity, high sensitivity and specificity, suitability for longitudinal studies, and relationship with the pathogenesis of the disease.

Intracranial yolk sac tumor in an adult patient: MRI, diffusion-weighted imaging and 1H MR spectroscopy features.

INTRODUCTION: Yolk sac tumors represent only 5%-7% of intracranial germ cell tumors, which comprise about 1% of all primary brain tumors in adults. Literature data about nonspecific imaging characteristics of these tumors are scant. We presented magnetic resonance imaging findings with diffusion-weighted imaging and proton magnetic resonance spectroscopy of this rare type of tumor in an adult patient. CASE REPORT: A 55-year-old man with progressive left side weakness, headache, dizziness and ataxia, underwent preoperative magnetic resonance imaging, diffusion-weighted imaging and proton magnetic resonance spectroscopy. After surgical resection and histological analysis, the final diagnosis of yolk sac tumor was established. Retrospective imaging analysis were performed in order to determine imaging and biochemical parameters that could be useful in the diagnostic evaluation of this tumor type. CONCLUSION: Though the imaging features of yolk sac tumor are not specific, morphoanatomical and metabolic imaging could offer the information that provides new insights into this tumor that may facilitate further therapeutic decision process and potentially provides better information regarding the disease prognosis.

Bálint-like syndrome as an unusual representation of non-convulsive status epilepticus.

The clinical signs of posterior cortex dysfunction are, due to their paucity and subtlety, very often ignored as non-specific during clinical evaluation of non-convulsive status epilepticus. Therefore, focal non-convulsive status epilepticus emerging from the posterior cortex, and especially the parietal lobes, can be fairly under-recognised. We report a 66-year-old patient with focal non-convulsive status epilepticus presenting as isolated Bálint-like syndrome, successfully treated to full clinical and electrophysiological recovery. The diagnostic and pathophysiological features are discussed. Focal non-convulsive status epilepticus can be associated with negative phenomena such as neuropsychological deficits mimicking those detected more often in degenerative and vascular brain diseases. [Published with video sequences].

Significance of magnetic resonance imaging in differential diagnosis of nontraumatic brachial plexopathy.

BACKGROUND/AIM: Nontraumatic brachial plexopathies may be caused by primary or secondary tumors, radiation or inflammation. The aim of this study was to present the significance of MRI in revealing the cause of nontraumatic brachial plexopathy. METHODS: A two-year retrospective study included 22 patients with nontraumatic brachial plexopathy. In all the patients typical clinical findings were confirmed by upper limb neurophysiological studies. In all of them MRI of brachial plexus was performed by 1.5 T scanner in T1 and T1 FS sequence with and without contrast, as well as in T2 and T2 FS sequences. RESULTS: Seven (32%) patients had brachial plexopathy with signs of inflammatory process, 5 (23%) patients had secondary tumors, in 4 (18%) patients multifocal motor neuropathy was established and in the same number (18%) of the patients postradiation fibrosis was found. Two patients (9%) had primary neurogenic tumors. CONCLUSION: According to the results of this study MRI is a method which may determine localization and cause of brachial plexopathy. MRI can detect focal nerve lesions when other methods fail to find them. Thus, MRI has a direct impact on further diagnostic and therapeutical procedures.

Proton magnetic resonance spectroscopy of the intrinsic tongue muscles in patients with myasthenia gravis with different autoantibodies.

OBJECTIVE: To assess lipid composition of the intrinsic tongue muscles in patients with myasthenia gravis (MG). METHODS: This study included 15 MG patients with antibodies against muscle-specific kinase (MuSK), 15 matched MG patients with antibodies against acetylcholine receptor (AChR) and 15 matched healthy subjects. Middle posterior region of the tongue was analyzed by single voxel point-resolved proton magnetic resonance spectroscopy (MRS) using 1.5T MRI scanner. RESULTS: MRS obtained from subject with AChR MG showed a broad resonance arising from methylene groups of lipids (PMN) with no observable shoulder attributed to methyl groups (PML). Full-width at half maximum (FWHM) of PMN+PML peak showed higher value in patients with AChR MG in comparison to healthy subjects and MuSK MG patients (p<0.05). In patients with MuSK MG, the shape and FWHM of PMN+PML peak was similar as in healthy subjects (p>0.05), with tendency toward increased ratio between PMN and resonance from vinyl protons of lipids (PV). In both AChR and MuSK MG, total creatine resonance (creatine+phosphocreatine, CP) was almost absent with significant increase of PMN/CP ratio in comparison to healthy subjects (p<0.05). CONCLUSION: MRS is useful in revealing muscle lipid composition in MG. In patients with AChR MG, MRS showed increased lipid content in the tongue muscles due to the lipid migration from intra- to extramyocellular space. Finding in patients with MuSK MG might reflect intramyocellular lipid deposition in the tongue. CP decrease in tongue muscles indicated impairment of oxidative metabolism in both AChR MG and MuSK MG.

[Transient lesion in the splenium of the corpus callosum and a sudden antiepileptic drugs withdrawal: a case with focal epilepsy in presurgical evaluation].

INTRODUCTION: A sudden withdrawal of antiepileptic drugs gives higher rate of epileptic seizures in the settings of video electroencephalography (vEEG), monitoring that is a subject to further registration and analysis. A very rare complication of this method is transient lesion of the splenium of corpus callosum (SCC) detected with brain MRI. CASE REPORT: We presented a patient with a 5-year history of pharmacoresistant epilepsy admitted to the Institute of Neurology (August, 2008) for vEEG monitoring. Interictal epileptic discharges but none seizure were recorded after the sudden withdrawal of antiepileptic medications, during 5 days of vEEG monitoring Initial brain MRI three days after vEEG monitoring revealed focal lesion in SCC, hyperintense on T2 and FLAIR sequence. A longitudinal radiological follow-up (7 and 49 days after initial acquisition) confirmed transient nature of the lesion without diffusion coefficient changes. CONCLUSION: SCC lesion, reversible and harmless, may occur after a sudden antiepileptic withdrawal. Its early detection makes further extensive neuroradiological and clinical examinations unnecessary.

[The use of magnetic resonance and MR angiography in the detection of cerebral infarction--a complication of pediatric bacterial meningitis].

BACKGROUND: Association of both cerebral infarction and acute bacterial meningitis is more common in younger patients than in the elderly. The rate of mortality and the frequency of sequela are very high inspite of the use of modern antibiotic therapy. In more than 30% of the cases of childhood bacterial meningitis, both arterial and venous infarctions can occur. The aim of this study was to present the role of the use of magnetic resonance (MRI), and MR angiography (MRA) in the detection of bacterial meningitis in children complicated with cerebral infarctions. METHOD: In the Centre for MR, the Clinical Centre of Serbia, 25 patients with the diagnosis of bacterial meningitis, of which 9 children with cerebral infarction whose clinical condition deteriorated acutely, despite the antibiotic therapy, underwent MRI and MR angiography examination on a 1T scanner. Examination included the conventional spin-echo techniques with T1-weighted saggital and coronal, and T2- weighted axial and coronal images. Coronal fluid attenuated inversion recovery (FLAIR) and the postcontrast T1-weighted images in three orthogonal planes were also used. The use MR angiography was accomplished by the three-dimensional time-of-flight (3D TOF) technique. RESULTS: The findings included: multiple hemorrhagic infarction in 4 patients, multiple infarctions in 3 patients, focal infarction in 1 patient and diffuse infarction (1 patient). Common sites of involvement were: the frontal lobes, temporal lobes and basal ganglia. The majority of infarctions were bilateral. In 3 of the patients empyema was found, and in 1 patient bitemporal abscess was detected. In 8 of the patients MR angiography confirmed inflammatory vasculitis. CONCLUSION: Infarction is the most common sequela of severe meningitis in children. Since the complication of cerebral infarction influences the prognosis of meningitis, repetitive MRI examinations are very significant for the evaluation of the time course of vascular involvement. The use of MRI, especially FLAIR imaging, confirmed its value in the detection and determination of the site and the extent of cerebral infarction. Non-invasive technique of examination, 3D TOF MR angiography clearly shoud show the presence of inflammatory vasculitis.

[FLAIR MR sequence in the diagnosis and follow-up of low-grade astrocytomas].

AIM: To evaluate the sensitivity of fluid-attenuated inversion recovery (FLAIR) sequence in the diagnosis and follow-up of the patients with low-grade astrocytomas compared with T2-weighted (T2W) sequence. METHODS: Twenty-four patients with biopsy-confirmed low-grade astrocytoma (age range, 15-66 years) underwent T1-weighted (T1W), T2W and FLAIR imaging with a superconducting unit 1.0 T. FLAIR images were qualitatively evaluated by comparison with T2W images by the three experienced neuroradiologists. To evaluate the diagnostic value of FLAIR, the neuroradiologists individually assessed the possibilities of the detection of lesions, as well as the possibilities of the differentiation of tumor from the surrounding edema on FLAIR vs. T2W images. Every examiner ranked FLAIR sequence vs. T2W in three degrees: worse, equal and better. RESULTS: The comparison of FLAIR with T2W spin-echo (SE) images with regard to the detection of the lesions showed that 82.8% of FLAIR studies were superior, 17.2% were of similar diagnostic value, and none was inferior to the T2W images. The comparison of images with regard to the differentiation of tumor boundaries vs. surrounding edema showed that 92.5% of FLAIR studies were superior, 7.5% were of similar diagnostic value, and none was inferior to the T2W images. CONCLUSION: Our results were similar to the previous studies' results concerning the advantages of FLAIR sequence in the diagnosis of low grade astrocytomas over T2W sequence. FLAIR was better at showing different tumor components, and at distinguishing CSF from the cystic component, and the postoperative cavity, compared with T2W images. Our conclusion was that FLAIR could be routinely used in the evaluation and follow-up of low-grade astrocytomas.