Specific MR sequences have been able to identify the loss of neuromelanin in the substantia nigra... more Specific MR sequences have been able to identify the loss of neuromelanin in the substantia nigra (SN) of early stage Parkinson's disease (PD) patients. Since this technique may have a significant impact in clinical patient management, easy and widely available imaging analysis is needed for routine use. In this study we compared a quantitative analysis with a visual assessment of SN neuromelanin-sensitive MR images in early stage PD patients, in terms of pattern changes recognition and diagnostic accuracy. The inclusion criteria were untreated "de novo" PD patients or a 2-5 year PD duration; in addition, age matched controls were enrolled. These were studied with a high-resolution T1-weighted MR imaging sequence at 3.0 Tesla to visualize neuromelanin. The primary outcome was the comparison of quantitative width measurement with visual assessment by experienced neuroradiologists of SN neuromelanin sensitive MR images for PD diagnosis. A total of 12 "de novo" PD patients, 10 PD patients with 2-5 year disease duration and 10 healthy controls were evaluated. We obtained a good accuracy in discriminating early-stage PD patients from controls using either a quantitative width measurement of the T1 high signal or a simple visual image inspection of the SN region. Visual inspection of neuromelanin-sensitive MR images by experienced neuroradiologists provides comparable results to quantitative width measurement in the detection of early stage PD SN changes and may become a useful tool inclinical practice.
The authors reviewed the diffusion tensor imaging (DTI) and tractography (DTT) of the normal brai... more The authors reviewed the diffusion tensor imaging (DTI) and tractography (DTT) of the normal brainstem and cerebellar white matter in normal volunteers, correlating it with structural magnetic resonance (MR) imaging and DTI data obtained in patients evaluated in our institution with movement disorders, including multisystem atrophy (MSA), spinocerebellar ataxia (SCA), progressive supra-nuclear palsy (PSP) and idiopathic Parkinson's disease (PD). DTI and tractography data demonstrated major white-matter fibers within the brain stem and cerebellum, including cortico-spinal tracts, transverse pontine fibers, medial lemniscus and cerebellar peduncles. Visualization of selective degeneration of these individual fibre tracts with DTI, in our cases, added qualitative data to the differential diagnosis of movement disorders.
Hypertensive encephalopathy is a neurologic syndrome caused by a marked and rapid rise of blood p... more Hypertensive encephalopathy is a neurologic syndrome caused by a marked and rapid rise of blood pressure above baseline levels. Efficacy of current anti-hypertensive drugs greatly diminished the frequency of this situation in which diagnosis is essentially based on clinical parameters. This can justify the few papers found in radiologic literature. Nevertheless it is sometimes important to exclude ischemic or hemorrhagic complications or establish a differential diagnosis with other neuropathologic conditions. Then a striking imagiologic picture of focal or diffuse reversible edema of cerebral white matter can be found. We present three clinical cases of hypertensive encephalopathy. Imagiologic findings are reviewed and correlated with the pathophysiologic basis of the disease.
Neurocysticercosis (NCC) is the most frequent parasitic disease of the central nervous system. Ot... more Neurocysticercosis (NCC) is the most frequent parasitic disease of the central nervous system. Other Portuguese works showed it to be endemic in the north of our country. The purpose of this paper is to aid the characterization of NCC in the geographic area of our Institution. We retrospectively reviewed the findings of computed tomography (CT) in 35 patients with NCC, including 23 adults and 12 children. There was no significant sex predominance in adults, however, in children the female/male ratio was 2. We found important clinical and radiological differences between adults and children. In the pediatric age group, the active forms were characteristically solitary or scarce inflammatory lesions. This radiologic picture was associated with neurologic focal signs. In these cases, a trial with anticysticercoid drugs is important to settle the diagnosis and avoid brain biopsy. Almost all of our cases (94%) were parenchymatous forms. This can be explained, in part, by the limitations ...
Neuroepithelial cysts, heterogeneous group of lesions, are fluid collections similar to CSF, line... more Neuroepithelial cysts, heterogeneous group of lesions, are fluid collections similar to CSF, lined by epithelial cells, frequently found in the lateral ventricles and choroidal fissure; intraparenchymal cysts are relatively uncommon. We report CT and MRI imaging findings of four intraparenchymal neuroepithelial cysts, two of which have histological confirmation of the diagnosis.
Limbic encephalitis with LGI1 antibodies may cause drug-resistant temporal lobe epilepsy. We repo... more Limbic encephalitis with LGI1 antibodies may cause drug-resistant temporal lobe epilepsy. We report a case of a young man with progressive drug-resistant focal epilepsy, hyperhidrosis, and memory impairment associated with a left mesial temporal lesion. Epilepsy surgery was performed with the provisional diagnosis of cortical dysplasia or tumour. A neuropathological study following amygdalohippocampectomy revealed limbic encephalitis and LGI1 antibodies were identified in the serum. Two and a half years after surgery, the patient remains seizure-free without medication, with normal memory and without hyperhidrosis. Although immunosuppression is the first-line therapy for autoimmune limbic encephalitis, this case suggests that, in selected cases, a lasting response can be achieved with surgery.
The removal of mesial temporal structures, namely amygdalohippocampectomy, is the most efficient ... more The removal of mesial temporal structures, namely amygdalohippocampectomy, is the most efficient surgical procedure for the treatment of epilepsy. However, disconnection of the epileptogenic zones, as in temporal lobotomy or, for different purposes, hemispherotomy, have shown equivalent results with less morbidity. Thus, authors of the present study began performing selective amygdalohippocampotomy in cases of refractory mesial temporal lobe epilepsy (TLE) to treat mesial temporal lobe sclerosis (MTLS). The authors conducted a retrospective analysis of all cases of amygdalohippocampotomy collected in a database between November 2007 and March 2011. Since 2007, 21 patients (14 males and 7 females), ages 20-58 years (mean 41 years), all with TLE due to MTLS, were treated with selective ablation of the lateral amygdala plus perihippocampal disconnection (anterior one-half to two-thirds in dominant hemisphere), the left side in 11 cases and the right in 10. In 20 patients the follow-up was 2 or more years (range 24-44 months, average 32 months). Clinical outcome for epilepsy 2 years after surgery (20 patients) was good/very good in 19 patients (95%) with an Engel Class I (15 patients [75%]) or II outcome (4 patients [20%]) and bad in 1 patient (5%) with an Engel Class IV outcome (extratemporal focus and later reoperation). Surgical morbidity included hemiparesis (capsular hypertensive hemorrhage 24 hours after surgery, 1 patient), verbal memory worsening (2 patients), and quadrantanopia (permanent in 2 patients, transient in 1). Late psychiatric depression developed in 3 cases. Operative time was reduced by about 30 minutes (15%) on average with this technique. Amygdalohippocampotomy is as effective as amygdalohippocampectomy to treat MTLS and is a potentially safer, time-saving procedure.
Tuberculosis is becoming an increasingly troublesome public health problem mostly because of inco... more Tuberculosis is becoming an increasingly troublesome public health problem mostly because of incomplete therapy of existing cases giving rise to multi-drug resistant strains and because of increase in immunodeficiency states from various causes. The disease affects preferentially economically underprivileged individuals. In this paper, we review the pathogenesis and radiological findings of meningoencephalic tuberculosis. Imaging manifestations are very pleomorphic and can mimic parenchymal cerebral mass lesions or meningeal processes of different nature. Although imaging findings are generally non-specific, modern imaging plays a key role in the diagnosis. A high index of suspicion in the appropriate clinical and laboratorial setting may promote rapid diagnosis and institution of therapeutic measures that avoid death or serious neurological consequences.
The interobserver variation in the magnetic resonance (MR) location of cerebral vein and dural si... more The interobserver variation in the magnetic resonance (MR) location of cerebral vein and dural sinus thrombosis (CVT) has not been previously reported. Four independent observers rated a convenience sample of 40 MR/MR angiographies to assess whether or not each dural sinus and major cerebral veins were occluded. Interobserver reliability was measured using j statistics. Interobserver agreement was comparable between the six pairs of raters. Agreement was excellent for thrombosis of the deep cerebral venous system (j ¼ 1.00), cerebellar veins (j ¼ 1.00), superior saggital sinus (j range: 0.82-1) and right jugular vein (j range: 0.84-0.95); good to excellent for the right transverse/sigmoid sinus (j range: 0.75-0.90) and the left jugular vein (j range: 0.65-0.85); moderate to excellent for the left lateral sinus (j range: 0.59-0.78) and the straight sinus (j range: 0.59-0.92); poor to good for the cortical veins (j range: 0.02-0.65). Agreement between observers varies with the location of CVT. It is good or excellent for most of the occluded sinus and veins, except for the cortical veins. This study suggests that information on the location of CVT can be reliably collected and used in multicentre studies.
Primary leptomeningeal tumors are rare and can have multiple origins. This young man presented an... more Primary leptomeningeal tumors are rare and can have multiple origins. This young man presented an intracranial hypertension syndrome and brain MRI features of diffuse leptomeningeal enhancement over cerebral and cerebellar hemispheres. A second cerebellar biopsy allowed the diagnosis of a primary diffuse leptomeningeal Primitive Neuroectodermal Tumor (PNET). Besides the paucity of reports of primary leptomeningeal PNET, its differentiation from primary leptomeningeal medulloblastomas is not always clear-cut and is discussed. Correspondence
We describe a patient with an acute middle cerebral artery ischemic stroke developing subtle invo... more We describe a patient with an acute middle cerebral artery ischemic stroke developing subtle involuntary movements of the paretic upper limb with cortical origin during rt-PA perfusion. Despite the multiple potential pathophysiological mechanisms for the relationship between thrombolysis and epileptic activity, seizures during this procedure are scarcely reported. Our hypothesis is that subtle and transient clinical seizures, like those described in our patient, may not be detected or are misdiagnosed as nonepileptic involuntary movements. We aimed to draw attention to the recognition challenge of this paroxysmal motor behavior, highlighting this clinical and neurophysiological identification using video recording and back-average analysis of the EEG.
Specific MR sequences have been able to identify the loss of neuromelanin in the substantia nigra... more Specific MR sequences have been able to identify the loss of neuromelanin in the substantia nigra (SN) of early stage Parkinson's disease (PD) patients. Since this technique may have a significant impact in clinical patient management, easy and widely available imaging analysis is needed for routine use. In this study we compared a quantitative analysis with a visual assessment of SN neuromelanin-sensitive MR images in early stage PD patients, in terms of pattern changes recognition and diagnostic accuracy. The inclusion criteria were untreated "de novo" PD patients or a 2-5 year PD duration; in addition, age matched controls were enrolled. These were studied with a high-resolution T1-weighted MR imaging sequence at 3.0 Tesla to visualize neuromelanin. The primary outcome was the comparison of quantitative width measurement with visual assessment by experienced neuroradiologists of SN neuromelanin sensitive MR images for PD diagnosis. A total of 12 "de novo" PD patients, 10 PD patients with 2-5 year disease duration and 10 healthy controls were evaluated. We obtained a good accuracy in discriminating early-stage PD patients from controls using either a quantitative width measurement of the T1 high signal or a simple visual image inspection of the SN region. Visual inspection of neuromelanin-sensitive MR images by experienced neuroradiologists provides comparable results to quantitative width measurement in the detection of early stage PD SN changes and may become a useful tool inclinical practice.
The authors reviewed the diffusion tensor imaging (DTI) and tractography (DTT) of the normal brai... more The authors reviewed the diffusion tensor imaging (DTI) and tractography (DTT) of the normal brainstem and cerebellar white matter in normal volunteers, correlating it with structural magnetic resonance (MR) imaging and DTI data obtained in patients evaluated in our institution with movement disorders, including multisystem atrophy (MSA), spinocerebellar ataxia (SCA), progressive supra-nuclear palsy (PSP) and idiopathic Parkinson's disease (PD). DTI and tractography data demonstrated major white-matter fibers within the brain stem and cerebellum, including cortico-spinal tracts, transverse pontine fibers, medial lemniscus and cerebellar peduncles. Visualization of selective degeneration of these individual fibre tracts with DTI, in our cases, added qualitative data to the differential diagnosis of movement disorders.
Hypertensive encephalopathy is a neurologic syndrome caused by a marked and rapid rise of blood p... more Hypertensive encephalopathy is a neurologic syndrome caused by a marked and rapid rise of blood pressure above baseline levels. Efficacy of current anti-hypertensive drugs greatly diminished the frequency of this situation in which diagnosis is essentially based on clinical parameters. This can justify the few papers found in radiologic literature. Nevertheless it is sometimes important to exclude ischemic or hemorrhagic complications or establish a differential diagnosis with other neuropathologic conditions. Then a striking imagiologic picture of focal or diffuse reversible edema of cerebral white matter can be found. We present three clinical cases of hypertensive encephalopathy. Imagiologic findings are reviewed and correlated with the pathophysiologic basis of the disease.
Neurocysticercosis (NCC) is the most frequent parasitic disease of the central nervous system. Ot... more Neurocysticercosis (NCC) is the most frequent parasitic disease of the central nervous system. Other Portuguese works showed it to be endemic in the north of our country. The purpose of this paper is to aid the characterization of NCC in the geographic area of our Institution. We retrospectively reviewed the findings of computed tomography (CT) in 35 patients with NCC, including 23 adults and 12 children. There was no significant sex predominance in adults, however, in children the female/male ratio was 2. We found important clinical and radiological differences between adults and children. In the pediatric age group, the active forms were characteristically solitary or scarce inflammatory lesions. This radiologic picture was associated with neurologic focal signs. In these cases, a trial with anticysticercoid drugs is important to settle the diagnosis and avoid brain biopsy. Almost all of our cases (94%) were parenchymatous forms. This can be explained, in part, by the limitations ...
Neuroepithelial cysts, heterogeneous group of lesions, are fluid collections similar to CSF, line... more Neuroepithelial cysts, heterogeneous group of lesions, are fluid collections similar to CSF, lined by epithelial cells, frequently found in the lateral ventricles and choroidal fissure; intraparenchymal cysts are relatively uncommon. We report CT and MRI imaging findings of four intraparenchymal neuroepithelial cysts, two of which have histological confirmation of the diagnosis.
Limbic encephalitis with LGI1 antibodies may cause drug-resistant temporal lobe epilepsy. We repo... more Limbic encephalitis with LGI1 antibodies may cause drug-resistant temporal lobe epilepsy. We report a case of a young man with progressive drug-resistant focal epilepsy, hyperhidrosis, and memory impairment associated with a left mesial temporal lesion. Epilepsy surgery was performed with the provisional diagnosis of cortical dysplasia or tumour. A neuropathological study following amygdalohippocampectomy revealed limbic encephalitis and LGI1 antibodies were identified in the serum. Two and a half years after surgery, the patient remains seizure-free without medication, with normal memory and without hyperhidrosis. Although immunosuppression is the first-line therapy for autoimmune limbic encephalitis, this case suggests that, in selected cases, a lasting response can be achieved with surgery.
The removal of mesial temporal structures, namely amygdalohippocampectomy, is the most efficient ... more The removal of mesial temporal structures, namely amygdalohippocampectomy, is the most efficient surgical procedure for the treatment of epilepsy. However, disconnection of the epileptogenic zones, as in temporal lobotomy or, for different purposes, hemispherotomy, have shown equivalent results with less morbidity. Thus, authors of the present study began performing selective amygdalohippocampotomy in cases of refractory mesial temporal lobe epilepsy (TLE) to treat mesial temporal lobe sclerosis (MTLS). The authors conducted a retrospective analysis of all cases of amygdalohippocampotomy collected in a database between November 2007 and March 2011. Since 2007, 21 patients (14 males and 7 females), ages 20-58 years (mean 41 years), all with TLE due to MTLS, were treated with selective ablation of the lateral amygdala plus perihippocampal disconnection (anterior one-half to two-thirds in dominant hemisphere), the left side in 11 cases and the right in 10. In 20 patients the follow-up was 2 or more years (range 24-44 months, average 32 months). Clinical outcome for epilepsy 2 years after surgery (20 patients) was good/very good in 19 patients (95%) with an Engel Class I (15 patients [75%]) or II outcome (4 patients [20%]) and bad in 1 patient (5%) with an Engel Class IV outcome (extratemporal focus and later reoperation). Surgical morbidity included hemiparesis (capsular hypertensive hemorrhage 24 hours after surgery, 1 patient), verbal memory worsening (2 patients), and quadrantanopia (permanent in 2 patients, transient in 1). Late psychiatric depression developed in 3 cases. Operative time was reduced by about 30 minutes (15%) on average with this technique. Amygdalohippocampotomy is as effective as amygdalohippocampectomy to treat MTLS and is a potentially safer, time-saving procedure.
Tuberculosis is becoming an increasingly troublesome public health problem mostly because of inco... more Tuberculosis is becoming an increasingly troublesome public health problem mostly because of incomplete therapy of existing cases giving rise to multi-drug resistant strains and because of increase in immunodeficiency states from various causes. The disease affects preferentially economically underprivileged individuals. In this paper, we review the pathogenesis and radiological findings of meningoencephalic tuberculosis. Imaging manifestations are very pleomorphic and can mimic parenchymal cerebral mass lesions or meningeal processes of different nature. Although imaging findings are generally non-specific, modern imaging plays a key role in the diagnosis. A high index of suspicion in the appropriate clinical and laboratorial setting may promote rapid diagnosis and institution of therapeutic measures that avoid death or serious neurological consequences.
The interobserver variation in the magnetic resonance (MR) location of cerebral vein and dural si... more The interobserver variation in the magnetic resonance (MR) location of cerebral vein and dural sinus thrombosis (CVT) has not been previously reported. Four independent observers rated a convenience sample of 40 MR/MR angiographies to assess whether or not each dural sinus and major cerebral veins were occluded. Interobserver reliability was measured using j statistics. Interobserver agreement was comparable between the six pairs of raters. Agreement was excellent for thrombosis of the deep cerebral venous system (j ¼ 1.00), cerebellar veins (j ¼ 1.00), superior saggital sinus (j range: 0.82-1) and right jugular vein (j range: 0.84-0.95); good to excellent for the right transverse/sigmoid sinus (j range: 0.75-0.90) and the left jugular vein (j range: 0.65-0.85); moderate to excellent for the left lateral sinus (j range: 0.59-0.78) and the straight sinus (j range: 0.59-0.92); poor to good for the cortical veins (j range: 0.02-0.65). Agreement between observers varies with the location of CVT. It is good or excellent for most of the occluded sinus and veins, except for the cortical veins. This study suggests that information on the location of CVT can be reliably collected and used in multicentre studies.
Primary leptomeningeal tumors are rare and can have multiple origins. This young man presented an... more Primary leptomeningeal tumors are rare and can have multiple origins. This young man presented an intracranial hypertension syndrome and brain MRI features of diffuse leptomeningeal enhancement over cerebral and cerebellar hemispheres. A second cerebellar biopsy allowed the diagnosis of a primary diffuse leptomeningeal Primitive Neuroectodermal Tumor (PNET). Besides the paucity of reports of primary leptomeningeal PNET, its differentiation from primary leptomeningeal medulloblastomas is not always clear-cut and is discussed. Correspondence
We describe a patient with an acute middle cerebral artery ischemic stroke developing subtle invo... more We describe a patient with an acute middle cerebral artery ischemic stroke developing subtle involuntary movements of the paretic upper limb with cortical origin during rt-PA perfusion. Despite the multiple potential pathophysiological mechanisms for the relationship between thrombolysis and epileptic activity, seizures during this procedure are scarcely reported. Our hypothesis is that subtle and transient clinical seizures, like those described in our patient, may not be detected or are misdiagnosed as nonepileptic involuntary movements. We aimed to draw attention to the recognition challenge of this paroxysmal motor behavior, highlighting this clinical and neurophysiological identification using video recording and back-average analysis of the EEG.
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Papers by Carlos Morgado