Paula Ricci Arantes

Performing functional magnetic resonance imaging in patients with Parkinson's disease treated with deep brain stimulation

Deep brain stimulation (DBS) is a relatively novel treatment in advanced Parkinsons disease (PD). Functional magnetic resonance imaging (fMRI) is a useful technique for examining the effects of DBS both within the basal ganglia and its cortical connectivity. There are technical difficulties in imaging patients with PD, and the DBS itself can generate image artifacts. We describe aspects related to optimizing the fMRI acquisition parameters in patients with DBS and the results of sensorimotor activation tasks performed by four PD patients during hand, foot, and tongue movements, both before and after DBS implant. Provided that all safety conditions are followed, it is possible to perform fMRI in patients with PD and DBS. The standard DBS surgical procedure has to be slightly modified in order to reduce image artifacts. The event‐related design provided increased power to detect sensorimotor cortex and basal ganglia activation.

Wavelet based time-varying vector autoregressive modelling

Vector autoregressive (VAR) modelling is one of the most popular approaches in multivariate time series analysis. The parameters interpretation is simple, and provide an intuitive identification of relationships and Granger causality among time series. However, the VAR modelling requires stationarity conditions which could not be valid in many practical applications. Locally stationary or time dependent modelling seem attractive generalizations, and several univariate approaches have already been proposed. In this paper we propose an estimation procedure for time-varying vector autoregressive processes, based on wavelet expansions of autoregressive coefficients. The asymptotic properties of the estimator are derived and illustrated by computer intensive simulations. We also present an application to brain connectivity identification using functional magnetic resonance imaging (fMRI) data sets.

Serpentine fibula polycystic kidney syndrome is part of the phenotypic spectrum of Hajdu–Cheney syndrome

Serpentine fibula polycystic kidney syndrome (SFPKS; MIM600330) is a rare skeletal dysplasia that has polycystic kidneys and dysmorphic facies as additional defining phenotypic components. The nosological classification of this disease has been debated as the condition shares features common to other skeletal dysplasias such as Melnick Needles syndrome (MNS; MIM309350) and Hajdu–Cheney Syndrome (HCS; MIM102500). Here, two previously reported cases of SFPKS are presented with emphasis on their phenotypic evolution. With the recent discovery that HCS is caused by mutations in NOTCH2, DNA from the both cases was examined and both were found to have truncating mutations in exon 34 of NOTCH2. The phenotypic evolution of SFPKS and this molecular analysis strongly suggest that SFPKS is part of the phenotypic spectrum of HCS and should no longer be classified as a distinct disease entity.

Inter- and intrareader variability in the interpretation of two radiographic classification systems for juvenile rheumatoid arthritis

ObjectiveTo evaluate the inter- and intrareader variability for interpretation of a modified Larsens radiographic classification system for juvenile rheumatoid arthritis (JRA) focused on osteochondral lesions and a conventional Larsens classification system, compared to a reference MR scoring system of corresponding images.Materials and methodsSeventy-five radiographs of 60 children with JRA, performed within a short interval of time from the MR examinations, were independently evaluated by three experienced radiologists, three diagnostic imaging residents and three rheumatologists, in two separate sessions, according to the two different classification methods, blinded to the corresponding MR images.ResultsThe inter- and intrareader concordance rates between the two radiographic classification systems and the MR-related radiographs were respectively poor and poor/moderate. The interobserver range of weighted kappa values for the conventional and the modified Larsens system respectively was 0.25–0.37 vs 0.19–0.39 for radiologists, 0.25–0.37 vs 0.18–0.30 for residents and 0.19–0.51 vs 0.17–0.29 for rheumatologists. The intrareader rate ranged from 0.17–0.55 for radiologists, 0.2–0.56 for residents, and 0.14–0.59 for rheumatologists.ConclusionAlthough the proposal of a new radiographic classification system for JRA focused on osteochondral abnormalities sounds promising, the low inter- and intrareader concordance rates with an MR-related radiographic system makes the clinical applicability of such a radiographic system less suitable.

Epilepsy syndromes associated with hypothalamic hamartomas

PURPOSE Hypothalamic hamartoma (HH) related epilepsy presents with gelastic seizures (GS), other seizure types and cognitive deterioration. Although seizure origin in GS has been well established, non-GS are poorly characterized. Their relationship with the HH and cognitive deterioration remains poorly understood. We analyzed seizure type, spread pattern in non-GS and their relationship with the epileptic syndrome in HH. METHODS We documented all current seizure types in six adult patients with HH-epilepsy with video-EEG monitoring, characterized clinical-electrographic features of gelastic and non-gelastic seizures and correlated these findings with cognitive profile, as well as MRI and ictal SPECT data. RESULTS Only four seizure types were seen: GS, complex partial (CPS), tonic seizures (TS) and secondarily generalized tonic-clonic seizures (sGTC). An individual patient presented either CPS or TS, but not both. GS progressed to CPS or TS, but not both. Ictal patterns in GS/TS and in GS/CPS overlapped, suggesting ictal spread from the HH to other cortical regions. Ictal SPECT patterns also showed GS/TS overlap. Patients with GS-CPS presented a more benign profile with preserved cognition and clinical-EEG features of temporal lobe epilepsy. Patients with GS-TS had clinical-EEG features of symptomatic generalized epilepsy, including mental deterioration. CONCLUSIONS Video-EEG and ictal SPECT findings suggest that all seizures in HH-related epilepsy originate in the HH, with two clinical epilepsy syndromes: one resembling temporal lobe epilepsy and a more catastrophic syndrome, with features of a symptomatic generalized epilepsy. The epilepsy syndrome may be determined by HH size or by seizure spread pattern.

Good surgical outcome in discordant ictal EEG-MRI unilateral mesial temporal sclerosis patients.

Purpose: Video electroencephalography (vEEG) monitoring of patients with unilateral mesial temporal sclerosis (uMTS) may show concordant or discordant seizure onset in relation to magnetic resonance imaging (MRI) evidence of MTS. Contralateral seizure usually leads to an indication of invasive monitoring. Contralateral seizure onset on invasive monitoring may contraindicate surgery. We evaluated long‐term outcome after anteromesial temporal lobectomy (AMTL) in a consecutive series of uMTS patients with concordant and discordant vEEG findings, uniformly submitted to AMTL on the MRI evidence of MTS side without invasive monitoring.

New insights in mucopolysaccharidosis type VI: Neurological perspective

OBJECTIVE Mucopolysaccharidosis type VI is a rare autosomal recessive storage disorder, caused by deficiency of arylsulfatase B. Data on neurological involvement in mucopolysaccharidosis type VI patients under enzyme-replacement therapy are limited. This study explores the neurological and magnetic resonance imaging findings in a sample of mucopolysaccharidosis type VI patients receiving enzyme-replacement therapy. METHODS We performed a cross-sectional study including six patients with biochemical confirmation of mucopolysaccharidosis type VI and at least 105 consecutive weeks (two years) receiving intravenous enzyme-replacement therapy. The protocol included a comprehensive clinical examination, brain and spinal cord magnetic resonance imaging for all subjects. RESULTS Overall, cognition was spared, while we found presence of hearing impairment, increasing in deep tendon reflexes and deep sensation reduction in three patients. In addition to the classical abnormalities related to other types of mucopolysaccharidosis, imaging studies demonstrated morphological changes in anatomy of middle cranial fossa and sella shape. Even in asymptomatic or mild compromised patients, spinal cord compression was found. In four patients we noticed atlantoaxial joint subluxation and three had cervical spinal stenosis. Degenerative processes involving vertebral column, including discal protrusion and axis abnormalities, were present in all patients. CONCLUSIONS Neuroaxis involvement was a universal finding and neurological examination might not predict the severity of the disease in course. Image studies should not be performed according exclusively clinical parameters for these patients, once we have demonstrated that neurological involvement may be silent in these patients.

Mucopolysaccharidosis type IVA: Evidence of primary and secondary central nervous system involvement

Mucopolysaccharidosis type IVA is a rare lysosomal storage disease caused by a deficiency of N‐acetylgalactosamine 6‐sulfatase. Studies usually focus on skeletal abnormalities and their consequences. This study explores the neurological manifestations in a cohort of mucopolysaccharidosis type IVA patients, with a detailed focus on brain and spinal magnetic resonance imaging (MRI) findings. We performed a cross‐sectional study involving nine patients with a biochemical confirmation of mucopolysaccharidosis type IVA. The protocol consists of a comprehensive clinical examination and brain and spinal cord MRI analysis for all subjects. The mean age was 16.4 years (±5.7) and the mean onset of symptoms was 11.5 months (±6.3). Overall, cognition was spared in all but one patient and motor weakness was a constant finding in all patients. Deep sensation impairment was found in six patients. The brain MRIs showed non‐specific white matter changes in two patients. Other abnormalities such as clival hypoplasia, basilar invagination, and arachnoid cists appeared in seven of the nine patients. Eight patients presented spinal cord compression, and in three of them, two spinal levels were compromised. Odontoid hypoplasia and degenerative features in the neuroaxis were present in all patients. Our experience with mucopolysaccharidosis type IVA patients supports the evidence of central nervous system involvement. We emphasize the importance of regular clinical assessments with complete MRI studies, as an attempt to detect the early signs of spinal cord compression. This evaluation may be especially important before surgical interventions, as occult lesions may become symptomatic and promote postoperative unfavorable outcomes.

S132. Ipsilateral cerebellar atrophy and crossed ictal cerebellar diaschisis in a case of Rasmussen encephalitis

Introduction Rasmussen encephalitis is a rare hemispheric inflammatory disease with progressive course leading to intractable focal seizures and neurological deficits, which can evolve to epilepsia partialis continua, hemiplegia, aphasia and other symptoms. Neuroimaging classically reveals progressive hemispheric atrophy, based on sequential computed tomography (CT) and magnetic resonance imaging (MRI). Contralateral injury to the cerebellum is expected, represented either by atrophy in anatomical images or by hypometabolism in functional studies as positron emission tomography-computed tomography (PET-CT) or single-photon emission computed tomography (SPECT). The postulated mechanism is interruption to the cerebropontine-cerebellar pathway, with resultant involvement of cerebellum ipsilateral to motor deficits. Methods We describe a case of Rasmussen encephalitis with unexpected cerebellar involvement, evidenced in MRI and ictal SPECT performed during preoperative evaluation. Results A 4-year-old boy had onset of focal clonic motor seizures involving right face and tongue seizures, which evolved to epilepsia partialis continua, progressive right hemiparesis and aphasia. Neuroimaging studies showed progressive left cerebral hemisphere and left cerebellum atrophy. Ictal spect disclosed right cerebellar diaschisis. The patient underwent left functional hemispherectomy. Pathology findings were compatible with Rasmussen’s encephalitis. Clinical follow-up reveals a patient that remains with no more seizures. Conclusion Considering cerebral hemisphere and cerebellum fiber connections, one would expect cerebellar atrophy contralateral to the involved cerebral hemisphere, as previously demonstrated. In our case, functional assessment with ictal SPECT showed contralateral diaschisis, but MRI demonstrated ipsilateral atrophy of cerebellum. These findings did not compromise clinical and surgical prognosis and anatomopathological studies confirmed the diagnosis of Rasmussen encephalitis. The reason for ipsilateral cerebellar involvement in our patient is unclear, but it appears to be more an anatomical variation of neuronal circuits between cerebral cortex and cerebellum than a marker of different clinical course.

Pearls & Oy-sters: Symptomatic innominate artery disease.

A 64-year-old man presented to the emergency department with left-sided weakness and speech impairment upon awakening. He had a history of multiple myocardial infarctions and had undergone coronary angioplasty and coronary artery bypass graft surgery 1 year previously. He was a heavy smoker and had arterial hypertension. He was taking aspirin 100 mg QD, clopidogrel 75 mg QD, simvastatin 40 mg QD, and enalapril 5 mg BID.