MRI in sporadic olivopontocerebellar atrophy and striatonigral degeneration.
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Cerebellum↗
Biomedical subjects
M Grisoli
Publications and source records attributed to M Grisoli.
Acquired hemidystonia in childhood: a clinical and neuroradiological study of thirteen patients.
A retrospective study of 13 patients (4 males/9 females) with acquired hemidystonia in childhood is reported. The mean age of onset of hemidystonia was 6.4 years (range 1-13.4 years); the mean duration of dystonia at the time of last follow-up was 11.4 years (range 3.6-23 years). Hemidystonia was caused by ischemic infarction in 9 patients and was attributed to perinatal trauma in 1; in 4 of the 9 patients with stroke and in the remaining 3 patients laboratory investigations were suggestive of primary antiphospholipid syndrome. Eleven of the 13 patients had delayed onset of dystonia: between 1 month and 8.9 years (mean 3.4 years). Ten patients had neuroradiological evidence of contralateral basal ganglia damage. A history of hemiparesis and evidence of striatal damage on CT or MRI were important risk factors for the development of dystonia. Response to medical treatment (trihexyphenidyl dose as high as 40 mg daily) in 5 patients was disappointing; 4 of the 5 patients who underwent functional stereotaxic operations were improved, but dystonia was still present at the end of the follow-up. Our study provides additional evidence that lesions of the striatum may induce dystonia, supporting the theory of striatopallido-thalamic disconnection. Furthermore, our results indicate that the occurrence of delayed dystonia must be considered in the diagnostic approach to childhood-onset dystonia.
Adolescent↗
Triventricular hydrocephalus: review of 71 cases evaluated at the Istituto Neurologico "C. Besta" Milan over the last 10 years.
The authors review 71 patients with triventricular hydrocephalus in whom a contrast-enhanced CT scan did not show any tumoral or vascular lesion that could have caused the hydrocephalus. The patients were subdivided into three age groups. The results of the neuroradiological examination, the surgical treatment, and the complications of the shunt procedure are analyzed, with special reference to the high number (13) of periaqueductal alterations of signal pattern found on MRI (interpreted as a "slow growing" neoplasm) and to the incidence and causes of shunt malfunction.
Adolescent↗
Magnetic resonance signal abnormalities along the pyramidal tracts in amyotrophic lateral sclerosis.
Magnetic resonance imaging (MRI) studies of the brain were reviewed in 16 patients with amyotrophic lateral sclerosis (ALS), representative of a large and homogeneously studied series, 11 of whom showed signal abnormalities along the pyramidal tracts. These were more frequent in patients with more severe upper motor neuron signs but did not correlate with disease severity. Our study suggests that MRI signal abnormalities along the pyramidal tracts are common in ALS and may reflect the severity of pyramidal tract degeneration.
Amyotrophic Lateral Sclerosis↗
Neurologic symptoms after epidural anaesthesia. Report of three cases.
We describe 3 patients, who exhibited neurological symptoms after single dose epidural anaesthesia. In patient 1 an unrecognized spinal arteriovenous fistula (AVF) caused paraparesis following epidural block. The dilated veins draining an AVF are space-occupying structures and the injection of the anaesthetic solution may have precipitated latent ischaemic hypoxia of the spinal cord due to raised venous pressure. In patient 2, epidural block was followed by postoperative permanent saddle pain and hypoaesthesia. The injection of the anaesthetic in a narrow spinal canal with multiple discal protrusions and restriction of interlaminar foramina may have acutely produced mechanical compression of the spinal cord or roots. Patient 3 exhibited post-epidural block spinal arachnoiditis. Although the few reported cases of this syndrome exhibit severe neurological damage, our patient presented with scarse symptoms. Our cases point out the importance of accurate neurological history and examination of candidates for epidural anaesthesia and of accurate anaesthetic history for neurological patients.
Adult↗
The effects of wallerian degeneration of the optic radiations demonstrated by MRI.
The effects of wallerian degeneration can be demonstrated by MRI as abnormal signal along the course of the degenerate fibres; they have previously been reported in the corticospinal tract. We report two cases of wallerian degeneration of the right optic radiations due to lesions of the right lateral geniculate body. The anatomy and the MRI visibility of the normal optic radiations are briefly discussed.
Brain Ischemia↗
Hemifacial spasm in a child.
Hemifacial spasm in a 10-year-old child is herein reported. Computed tomography and angiography were normal. Magnetic resonance imaging showed an anomalous vascular structure, probably a redundant loop arising from AICA or PICA, which was identified at surgery. The spasm, presumably due to vascular compression at the root entry zone of the right facial nerve, promptly and completely remitted after surgical decompression, without functional deficits. Atypical clinical features, as well as pre- and postoperative neurophysiological findings supporting the microvascular compression theory, are discussed.
Cerebellum↗
Technical basis for magnetic resonance images.
The spin-echo procedure is the basic technique in a magnetic resonance (MR) study (the magnetization vector is flipped by 90 degrees onto the ortogonal plane to the main magnetic field). Very soon after the MR procedure was developed, it was pointed out how important it is to achieve the needed contrast with shorter repetition times (TRs) to reduce the imaging time. Recently, fast imaging techniques have been introduced (partial flip angles, short TRs, and the lack of 180 degrees radiofrequency pulses to refocus the spins are their main characteristics; the spins are refocused by the application of a gradient reversal technique). These techniques are particularly needed in pediatric neuroradiology, where the examination time must be as short as possible. At present, partial flip-angle techniques are almost completely replacing the conventional spin-echo procedure, but the variations in flip angle could result in a change in contrast. For these reasons, conventional spin-echo techniques may still be useful in a routine MR study.
Brain Diseases↗
Olivopontocerebellar atrophy: MR diagnosis and relationship to multisystem atrophy.
Clinical diagnosis of olivopontocerebellar atrophy (OPCA) must be confirmed by radiologic demonstration of atrophy in an appropriate distribution. OPCA may be associated with degeneration of other systems in multisystem atrophy (MSA). The authors report 23 cases of OPCA, eight of which were associated with MSA. Atrophy involved the cerebellum, pons, and middle cerebellar peduncles in all cases. On intermediate and T2-weighted magnetic resonance (MR) images, abnormal signal intensity was always observed in the transverse pontine fibers, middle cerebellar peduncles, and cerebellum, structures known from pathologic study to degenerate in OPCA. Pyramidal tracts and superior cerebellar peduncles stood out because of their normal signal intensity. Of the eight patients with MSA, four also had variable abnormal signal intensities in the putamen. The authors believe that the combination of atrophy and abnormal signal intensity in the appropriate distribution strongly supports the diagnosis of OPCA. In some cases, MR imaging may demonstrate involvement of different systems, thus confirming the diagnosis of MSA.
Adult↗
MRI in internal carotid artery dissection.
We report two cases of internal carotid artery dissection in which MRI unequivocally demonstrated the intramural hematoma. We propose that, whenever the clinical presentation or the angiogram suggest arterial dissection, MRI be done to confirm the diagnosis.
Carotid Artery Diseases↗
[Magnetic resonance in brain tumors: a classification based on signal behavior in multiple echo sequences].
MR is generally known to be more sensitive but less specific than CT in the detection of brain lesions. In our opinion multiple echo sequences can markedly improve MR specificity in the diagnosis of tumors. We reviewed a series of 343 intracranial tumors studied with MR using multiple echo sequences and histologically verified. On the basis of the different signal patterns we divided brain tumors into 5 classes. Class 1: the signal intensity of the tumor increases progressively in T2 WI (100% of craniopharyngiomas, 21/21; 100% of epidermoid tumors, 12/12; 81% of astrocytomas (grades I to III), 64/79; 65% of neurinomas, 30/46). Class 2: the signal intensity of the lesion decreases progressively in T2 WI: A) the tumor has higher signal intensity than the parenchyma in all echoes (100% of medulloblastomas, 14/14; 53% of pituitary adenomas, 15/28); B) the tumor has the same signal intensity as the parenchyma in late echo acquisitions (100% of ependymal tumors, 12/12; 60% of meningiomas, 25/41). Class 3: the tumor has the same signal intensity as the parenchyma in all echoes (34% of meningiomas, 14/41). Class 4: glioblastoma model: one or more cysts of high signal intensity in T2 WI and slightly hyperintense nodules and/or rings and hyperintense peritumoral edema (73% of glioblastomas, 35/48; 72% of metastases, 18/25). Class 5: oligodendroglioma model: mixed hyper/hypointense pattern; cyst, calcifications and edema are very difficult to recognize within the lesion (95% of oligodendrogliomas, 18/19). The signal pattern was sometimes characteristic but never pathognomonic. Nevertheless, this classification proved to be an useful criterion to restrict the number of possible diagnoses. The study of T1 and T2 values seems to be less useful.
Brain↗
Problems and perspectives of diagnostic imaging: the pineal region.
In 1970 the state of the art in neuroradiological diagnosis was considered satisfactory enough, if not almost perfect, by the people working in this field. But when a few years later Computerized Tomography appeared, a new impressive standard in neuroradiological resolution was achieved, moreover with a non-invasive method. In the '80 further improvement was brought by several striking new diagnostic technologies, such as Magnetic Resonance, Positron Emission Tomography and Single Photon Emission Computed Tomography which allow the physician to achieve a new standard in non-invasive high resolution neuro-imaging which was simply unbelievable a few years ago. A new era is now beginning in the neuro-radiological sciences in which the new techniques surely allow the diagnosis towards disease previously escaping the neuro-radiological observation.
Brain Neoplasms↗
Superficial siderosis of the CNS: MR diagnosis and clinical findings.
PURPOSE: To report the clinical and neuroradiologic findings of superficial siderosis of the CNS, due to chronic subarachnoid bleeding of unknown origin. MATERIALS AND METHODS: We observed seven cases. The main clinical manifestations were progressive deafness and ataxia. Four patients had had previous cranial or cervical trauma, with root avulsion in two, many years before onset of deafness and ataxia. Neuroradiologic studies included MR (0.5 T in four and 1.5 T in three) and angiography of the brain in all cases, CT in six cases, MR of the spine in six, and myelography in four. RESULTS: MR demonstrated a rim of marked hypointensity in T2-weighted images, consistent with hemosiderin deposits, on the surface of cerebellum, brain stem, inferior part of cerebral hemispheres, and spinal cord. CT showed cerebellar atrophy in five cases, and a rim of mild hyperdensity around the brain stem in two. Angiographic studies were negative. Myelography showed cervical nerve root avulsion in two cases and a cervicodorsal extradural cyst in one. Cerebrospinal fluid contained RBCs in all the six examined cases. CONCLUSION: Although CT may occasionally suggest the diagnosis of superficial siderosis, MR demonstrates this abnormality to better advantage.
Adult↗
Hemiballism in a patient with probable multiple system atrophy.
We report a patient with long-standing asymmetrical parkinsonism, cerebellar ataxia and dysautonomia, suggestive of multiple system atrophy (MSA). However, the patient also developed involuntary repetitive movements similar to ballic dyskinesias and mental deterioration. MRI revealed major involvement of both posterior fossa structures and basal ganglia. The case would be accommodated within a rubric of MSA widened to include involvement of the subthalamic nucleus and the medial part of the pallidum, pathology which may account for the ballic movements. Additionally the patient's cognitive and behavioural disturbances suggest an impairment of striato-prefrontal cortex loop.
Autonomic Nervous System Diseases↗