Diffusion-weighted MRI hyperintensity patterns differentiate CJD from other rapid dementias.

BACKGROUND: Diffusion-weighted imaging (DWI) and fluid-attenuated inversion recovery (FLAIR) MRI have high sensitivity and specificity for Creutzfeldt-Jakob disease (CJD). No studies, however, have demonstrated how MRI can distinguish CJD from nonprion causes of rapidly progressive dementia (npRPD). We sought to determine the diagnostic accuracy of MRI for CJD compared to a cohort of npRPD subjects. METHODS: Two neuroradiologists blinded to diagnosis assessed DWI and FLAIR images in 90 patients with npRPD (n = 29) or prion disease (sporadic CJD [sCJD], n = 48, or genetic prion disease [familial CJD, n = 6, and Gerstmann-Sträussler-Scheinker, n = 7]). Thirty-one gray matter regions per hemisphere were assessed for abnormal hyperintensities. The likelihood of CJD was assessed using our previously published criteria. RESULTS: Gray matter hyperintensities (DWI > FLAIR) were found in all sCJD cases, with certain regions preferentially involved, but never only in limbic regions, and rarely in the precentral gyrus. In all sCJD cases with basal ganglia or thalamic DWI hyperintensities, there was associated restricted diffusion (apparent diffusion coefficient [ADC] map). This restricted diffusion, however, was not seen in any npRPD cases, in whom isolated limbic hyperintensities (FLAIR > DWI) were common. One reader's sensitivity and specificity for sCJD was 94% and 100%, respectively, the other's was 92% and 72%. After consensus review, the readers' combined MRI sensitivity and specificity for sCJD was 96% and 93%, respectively. Familial CJD had overlapping MRI features with sCJD. CONCLUSIONS: The pattern of FLAIR/DWI hyperintensity and restricted diffusion can differentiate sCJD from other RPDs with a high sensitivity and specificity. MRI with DWI and ADC should be included in sCJD diagnostic criteria. New sCJD MRI criteria are proposed.

Engagement of the medial temporal lobe in verbal and nonverbal memory: assessment with functional MR imaging in healthy subjects.

BACKGROUND AND PURPOSE: The hippocampus and parahippocampal gyrus have a central role in the acquisition of new memories. Although functional MR imaging (fMRI) can provide information on the functional status of these brain regions, it has not reached widespread use in the presurgical assessment of patients undergoing temporal lobectomy. We aimed to evaluate whether simple memory-encoding paradigms could be used to elicit robust activations in the hippocampus and parahippocampal gyrus and to determine the lateralization of verbal and nonverbal memory. We also studied the relative contribution of the anterior and posterior portions of these structures. MATERIALS AND METHODS: We conducted this study on 16 healthy subjects by performing event-related fMRI using 3 memory encoding tasks with words, objects, and faces. In addition to a second-level group analysis, region-of-interest (ROI)-based measurements of the signal intensity percent change and of the percentage of activated voxels, determined at 2 thresholds, were performed. ROIs were drawn on the hippocampus and parahippocampal gyrus, divided into anterior and posterior segments. RESULTS: We found overall left-lateralized activation with words, bilateral activation with objects, and right-lateralized activation with faces. In particular, significant hippocampal activations were observed with all 3 categories of stimuli, and the head of the hippocampus was generally more engaged than its body and tail. Data on the signal intensity percent change and percentage of activated voxels are provided for each ROI and task. CONCLUSIONS: The combination of these 3 undemanding memory tasks could be considered, following appropriate validation, as a tool to assess the functional status of the medial temporal lobe in clinical settings.

Natural history and management of brainstem gliomas in adults. A retrospective Italian study.

Brainstem gliomas in adults are rare tumors, with heterogeneous clinical course; only a few studies in the MRI era describe the features in consistent groups of patients. In this retrospective study, we report clinical features at onset, imaging characteristics and subsequent course in a group of 34 adult patients with either histologically proven or clinico-radiologically diagnosed brainstem gliomas followed at two centers in Northern Italy. Of the patients 18 were male, 14 female, with a median age of 31. In 21 of the patients histology was obtained and in 20 it was informative (2 pilocytic astrocytoma, 9 low-grade astrocytoma, 8 anaplastic astrocytoma and 1 glioblastoma). Contrast enhancement at MRI was present in 14 patients. In all of the 9 patients who were investigated with MR spectroscopy, the Cho/NAA ratio was elevated at diagnosis. In 8 of the patients, an initial watch and wait policy was adopted, while 24 were treated shortly after diagnosis with either radiotherapy alone [4] or radiotherapy and chemotherapy [20] (mostly temozolomide). Only minor radiological responses were observed after treatments; in a significant proportion of patients (9 out of 15) clinical improvement during therapy occurred in the context of radiologically (MRI) stable disease. Grade III or IV myelotoxicity was observed in 6 patients. After a follow-up ranging from 9 to 180 months, all but 2 patients have progressed and 14 have died (12 for disease progression, 2 for pulmonary embolism). Median overall survival time was of 59 months. Investigation of putative prognostically relevant parameters showed that a short time between disease onset and diagnosis was related to a shorter survival. Compared with literature data, our study confirms the clinical and radiological heterogeneity of adult brainstem gliomas and underscores the need for multicenter trials in order to assess the efficacy of treatments in these tumors.

Deep brain stimulation as a functional scalpel.

Since 1995, at the Istituto Nazionale Neurologico "Carlo Besta" in Milan (INNCB,) 401 deep brain electrodes were implanted to treat several drug-resistant neurological syndromes (Fig. 1). More than 200 patients are still available for follow-up and therapeutical considerations. In this paper our experience is reviewed and pioneered fields are highlighted. The reported series of patients extends the use of deep brain stimulation beyond the field of Parkinson's disease to new fields such as cluster headache, disruptive behaviour, SUNCt, epilepsy and tardive dystonia. The low complication rate, the reversibility of the procedure and the available image guided surgery tools will further increase the therapeutic applications of DBS. New therapeutical applications are expected for this functional scalpel.

A pilot study of the reading processes combining reading-related potentials (RRPs) and fMRI.

Aim of this work is to describe temporally and spatially the activation of the cerebral areas involved in reading processes by combining fMRI and reading-related potentials (RRPs). RRPs and fMR images were recorded in separate studies during a specifically designed experimental procedure. The protocol consisted of three visual tasks of increasing complexity. In the first two tasks subjects were asked to passively watch at letters and symbols respectively without making any effort in reading or articulating silently them. In the third task subjects were asked to read aloud letters appearing on a screen at a rate of 0.5 Hz. 7 young healthy subjects participated in the experiment. The analysis of RRPs highlighted the following results. During non-alphabetic symbols presentation the amplitude of the potentials was lower in comparison to presentation of letters. Reading aloud generated RRPs of greater amplitude than implicit reading. The analysis of fMRI scans revealed that the visual presentation of both letters and symbols produced similar activation of primary visual areas. Besides these areas, reading aloud activated the motor and pre-motor cortices and the left anterior temporal lobe. The combined analysis of RRPs and fMRI characterizes both temporally and spatially the development of reading processes.

Idiopathic, intrinsic haematoma of the third cranial nerve.

We describe an exceptional case of an intrinsic, spontaneous haematoma of the oculomotor nerve and review the literature. We conclude that, even in an elderly patient, an isolated cranial nerve palsy should be extensively investigated and, when necessary, surgically treated, since a good functional recovery is possible.

CT-guided neurosurgery: preliminary experience.

BACKGROUND: With the possibility of CT systems becoming more handy and sophisticated, intraoperative CT was introduced in a few neurosurgical Centres with better results in lesion removal and surgical outcome. METHOD: At our Institution a mobile CT scanner was recently used for intraoperative evaluation (Philips Tomoscan M). For 27 tumour resections performed with a neuronavigation system, and 23 deep brain electrode positioning examinations, an intraoperative CT was employed. In addition the CT scanner was used in the recovery room for a postoperative control in 198 patients. FINDINGS: Our preliminary experience used for a real time evaluation of the treated patients, permitted to verify an incomplete removal in 23/27 cases. Evaluation of stereotactic electrode position in relation to the planned target was also possible and demonstrated a correct position in 21 cases. INTERPRETATION: Intraoperative CT scan is a useful system that permits to modify neuronavigation planning and is able to give information to the surgeon for better tumour removal, rule out possible hemorrhagic complications, and suitable deep brain electrode positioning.

Reversal of CSF positivity for JC virus genome by cidofovir in a patient with systemic lupus erythematosus and progressive multifocal leukoencephalopathy.

We report the case of a 36-year-old woman affected by systemic lupus erythematosus who developed rapidly progressive multifocal leukoencephalopathy. Cidofovir therapy induced disappearance of JC virus genome from the cerebrospinal fluid and stabilization of the MRI picture. Despite the fatal outcome after a few months of disease, cidofovir treatment deserves further testing as single antiviral therapy in HIV-negative PML patients.

Doxorubicin for acromegaly: a case report.

We report the case of an acromegalic woman, aged 35 years, with a huge GH-secreting tumor, repeatedly treated with neurosurgery and radiotherapy, not responsive to bromocriptine (Br) and octreotide (SMS), whose clinical picture evolved to coma due to endocranic hypertension. Since remnant size was too large to be further treated by surgery, chemotherapy with doxorubicin (DOX) (100 mg i.v. every three weeks up to 0.5 mg/m2 over 7 months) was started. Treatment was followed by a rapid improvement of clinical picture with resumption out of coma, progressive decline of GH levels (from 800 ng/ml to 15 ng/ml) and a slight shrinkage of tumor. No side effects were observed during DOX administration. We suggest that in those few acromegalic patients resistant both to SMS and Br, and with poor prognosis, DOX may be effectively used.