Intracranial findings in progressive facial hemiatrophy.

There have been infrequent reports of cerebral lesions associated with progressive facial hemiatrophy. Six children with progressive facial hemiatrophy were evaluated. Four were referred for evaluation of neurological deficits: 2 with seizures, one with left hemiparesis and one with learning problems. The remaining 2 patients had only facial hemiatrophy. Cranial computed tomography (CT) in 5 patients revealed the bony and soft tissue defects, but cerebral calcifications were seen in only 3 patients. Cranial magnetic resonance imaging (MRI) demonstrated areas of increased signal in the ipsilateral white matter on T2 weighted images in all 5 patients with upper facial atrophy. Ipsilateral cerebral lesions with progressive facial hemiatrophy may be more common than once believed. MRI sometimes reveals abnormalities of the white matter even in patients without neurologic symptoms, and may be more sensitive than CT in the diagnostic evaluation of patients with progressive facial hemiatrophy.     

Progression of cerebral white matter lesions: 6-year results of the Austrian Stroke Prevention Study

More than half of all elderly people have some degree of cerebral white matter lesions. However, the rate of progression of these lesions is uncertain. We aimed to assess the progression of lesions in community-dwelling volunteers aged 50-75 years without neuropsychiatric disease. We used MRI to grade and measure the total volume of white matter lesions in 296 volunteers at baseline, 3 years, and 6 years. 58 participants with no lesions and 123 with punctate abnormalities at baseline had a low tendency for lesion progression, whereas 14 participants with early confluent and nine with confluent lesions underwent median increases of 2.7 cm(3) (IQR 0.5-5.9) and 9.3 cm(3) (7.1-21.0), respectively, in lesion volume at 6 years. Lesion grade at baseline was the only significant predictor of lesion progression (p<0.0001). Punctate white matter lesions are not progressive and are thus benign, whereas early confluent and confluent white matter abnormalities are progressive, and thus malignant.     

Magnetic resonance imaging of central nervous system lesions in patients with lupus erythematosus. Correlation with clinical remission and antineurofilament and anticardiolipin antibody titers

Clinical, magnetic resonance imaging (MRI), and serologic studies were performed on 11 patients with diffuse central nervous system (CNS) systemic lupus erythematosus and 8 patients with focal CNS lupus. MRI of patients with diffuse clinical disease showed symmetrically distributed areas of increased signal intensity in the subcortical white matter; these resolved after treatment with high-dose methylprednisolone. These patients' sera contained elevated levels of antineurofilament antibodies. Patients with focal CNS lupus had areas of increased signal intensity and atrophic changes in regions corresponding to the major cerebral vessels. These MRI abnormalities did not improve after treatment with high-dose steroids. The sera of patients with focal CNS lupus had elevated levels of cardiolipin and lupus anticoagulant but normal levels of antineurofilament antibody. Our findings suggest that results of a combined clinical, MRI, and serologic evaluation of patients with CNS lupus may predict the response of patients to high-dose steroid therapy.     

Clinical significance of cerebral white matter lesions in older Asians with suspected dementia

BACKGROUND: cerebral white matter lesions are commonly seen on neuroimaging in older people and have been associated with clinical features such as gait abnormalities, urinary incontinence and depression. The significance of cerebral white matter lesions in older people with dementia remains uncertain. OBJECTIVES: to study the association between cerebral white matter lesions and the presence or absence of dementia in a group of elderly Asian patients; and to determine the clinical significance of cerebral white matter lesions in patients who are diagnosed to have dementia in terms of associated clinical features and the impact of cerebral white matter lesions on cognitive status. METHODS: for the first objective, the records of 141 older people of Asian ethnicity presenting to a memory clinic for the evaluation of suspected dementia were reviewed to compare the prevalence of cerebral white matter lesions in patients who did not fulfil the criteria for dementia, patients diagnosed to have Alzheimer's disease and patients diagnosed to have vascular dementia. For the second objective, 115 of these patients who were diagnosed to have dementia were studied to determine if demented patients with cerebral white matter lesions were more likely to have urinary incontinence, Parkinsonism, depression and greater severity of dementia. In addition, a comparison was made between demented patients with cerebral white matter lesions and those without cerebral white matter lesions in terms of psychometric assessment scores. RESULTS: cerebral white matter lesions were more common in Asian patients with vascular dementia. Demented patients with cerebral white matter lesions were also found to have more severe dementia and greater functional disability. CONCLUSION: cerebral white matter lesions are common, and are associated with greater functional disability in elderly Asian patients with dementia.     

Central nervous system involvement in adults with haemophagocytic lymphohistiocytosis: a single-center study

Hemophagocytic lymphohistiocytosis (HLH) is a rare multisystem disorder characterized by proliferation and diffuse infiltration multiple organs with histiocytes, including the central nervous system (CNS). Neurological manifestations of HLH have been recognized in different studies with children, but they remain relatively ill-defined in adults with HLH. From March 2008 to October 2014, 289 adult patients with HLH were admitted to our center. Clinical, radiological, and cerebral spinal fluid (CSF) data of the patients with CNS involvement were reviewed, and a retrospective study in our single-center was carried out. CNS involvement was observed in 29 patients (10%) either in their diagnosis process or during disease course. CNS symptoms included disturbance of consciousness, cranial nerve palsies, seizures, headache, limb paralysis, irritability, meningism, and memory loss. CSF analysis was conducted in 17 patients (59%). Among them, 11 patients (65%) were reported as having abnormal CSF. Neuroradiological studies were performed in 25 patients (86%). Among the 13 cases that underwent CT scan, one patient hemorrhaged. Single or multiple hypodense foci were detected in the other 2 patients. Magnetic resonance imaging (MRI) abnormalities were found in 15 patients, including focal lesions in cortical and adjacent subcortical regions with or without variable nodular or ring contrast-enhancement, multiple lesions in white matter, diffuse white matter signal changes, and meningeal enhancement. Basal ganglia, cerebellum, and brainstem lesions were also observed. CNS involvement could also be found in adult patients with HLH, but not as frequent as it was in children. The clinical manifestations could be diversified. By carrying out rigorous CNS examinations, an early diagnosis could be made and it was of the utmost importance for the prevention of further lesions.     

Cerebral white matter lesions in primary Sj?gren's syndrome: a controlled study.

OBJECTIVE: To determine the prevalence of neurological and magnetic resonance imaging (MRI) abnormalities in a well defined population of unselected patients with primary Sj?gren's syndrome (SS) and age and sex matched healthy patients. METHODS: Thirty patients with SS and 29 age and sex matched controls were examined by a neurologist and subsequently underwent MRI scanning with a 1.0 Tesla Siemens Impact MR scanner. Scans were graded by a neuroradiologist blinded to the clinical status of each subject. The number and location of white matter lesions > 3 mm in long axis (to exclude non-specific perivascular changes) were recorded for each subject. RESULTS: There was a significant increase in lesions detected by MRI in SS patients versus controls (p = 0.02) including deep white matter lesions (p = 0.03) and subcortical white matter lesions (p = 0.02). The presence of white matter lesions did not correlate with serum IgG or rheumatoid factor levels, or with presence of anticardiolipin antibodies. No subjects had symptoms or signs of serious neurological disease including multiple sclerosis, and corpus callosal lesions commonly seen in multiple sclerosis were notably absent in this study. CONCLUSION: Cerebral white matter lesions detected by MRI are more frequent in patients with primary SS than control subjects, yet do not appear to be associated with significant clinical manifestations. Although the pathological nature of these lesions is yet to be defined, their presence should not be over-interpreted.     

Transient tetraparesis after intrathecal and high-dose systemic methotrexate

 Aggressive polychemotherapy, intrathecal cytostatic prophylaxis and cranial irradiation have contributed to the remarkable improvement in the prognosis of acute lymphoblastic leukemia (ALL) and subtypes of high-grade non-Hodgkin's lymphoma (NHL) and the reduction of central nervous system (CNS) relapses. Early and late neurologic changes have been observed after different CNS-directed therapies. We report on the rare event of an acute tetraparesis after methotrexate (MTX) without other CNS-directed therapy. A young female with a diffuse large B-cell lymphoma developed signs of meningeal irritation a few hours after intrathecal prophylaxis with MTX, cytosine-arabinoside and dexamethasone. She recovered quickly. Ten days after her last course of systemic chemotherapy including high dose MTX she was admitted with a tetraparesis and motoric aphasia. A computer assisted tomography (CT) scan was normal. On magnetic resonance imaging (MRI) hyperintense white matter lesions were visible in the periventricular white matter. Initially, the radiologic signs were progressive while the patient's clinical condition improved. MRI controls after complete neurologic normalization revealed delayed partial regression of the white matter abnormalities. The patient has now been free of neurologic symptoms for 16 months. This case report demonstrates acute and subacute neurotoxic effects of MTX in the same patient and illustrates that radiologic CNS changes can persist irrespective of the disappearance of clinical symptoms. Received: March 13, 1998 / Accepted: July 29, 1998     

Central nervous system involvement in hepatitis C virus cryoglobulinemia vasculitis: a multicenter case-control study using magnetic resonance imaging and neuropsychological tests

OBJECTIVE: Involvement of the central nervous system (CNS) in patients with hepatitis C virus (HCV) mixed cryoglobulinemia (MC) is rare. The mechanism by which brain lesions are produced is unclear. We investigated these phenomena by clinical evaluation (neuropsychological tests) and cerebral magnetic resonance imaging (MRI) studies in patients with HCV-MC vasculitis. METHODS: This prospective study included 40 patients with MC vasculitis and chronic active HCV infection (HCV RNA+), 11 HCV controls without MC, and 36 healthy controls, matched for sex and age. A battery of 10 standardized neuropsychological tests was administered by one experienced neuropsychiatrist. All patients underwent cerebral MRI investigation. RESULTS: Twenty-four of the 27 (89%) evaluated patients with HCV-MC had a deficiency in one or more of the 10 cognitive domains examined. The most commonly involved domains were those of attention (70%), executive functions (44%), visual construction (37%), and visual spatial functions (33%). The number of impaired cognitive functions was significantly higher in patients with MC vasculitis than in HCV controls (2.18 +/- 1.84 vs 0.87 +/- 3.1; p < 0.05). MRI analysis showed that HCV-MC patients had a higher mean number of total (7.03 +/- 9.9 vs 0.90 +/- 1.81 and 2.03 +/- 3.1; p < 0.05) and periventricular (2.4 +/- 3.0 vs 0.38 +/- 0.5 and 0.8 +/- 1.4; p < 0.05) white matter high intensity signals than HCV controls and healthy controls, respectively. CONCLUSION: The high frequency of impaired cognitive function and the extent of MRI brain abnormalities in patients with HCV-associated mixed cryoglobulinemia vasculitis strongly suggest specific inflammatory involvement of the CNS.     

缺血性脑白质病变的临床研究进展

对健康老年人和动脉粥样硬化患者进行头部MRI和CT扫描常可发现缺血性脑白质病变.缺血性脑白质病变被认为是脑小血管病变的一种表现,可引起认知功能障碍等症状,并可能预测颅内或颅外缺血性事件等.文章对近年来脑白质病变及其发病机制和临床意义等方面的研究进展做了综述.     

Inborn errors and demyelination: MRI and the diagnosis of white matter disease

Summary The progress and extent of myelination can be assessed using magnetic resonance imaging (MRI). Myelination is delayed or diminished in several inherited metabolic abnormalities presenting in early life. Only minimal myelination of the CNS occurs in Pelizaeus-Merzbacher disease. Dysmyelination tends to produce fairly symmetrical lesions affecting white matter. In many mitochondrial enzyme and some lysosomal defects, the grey matter is also involved. The appearances and in particular the distribution on MRI and/or CT are characteristic in some conditions and the diagnosis is limited in others. Demyelination due to inflammatory disorders typically causes multifocal white matter lesions, recurrent in multiple sclerosis, monophasic in acute disseminated encephalomyelitis, extending in progressive multifocal leukoencephalopathy and classically involving the pons or corpus callosum in myelinolysis. Hypoxic ischaemic lesions may be metabolically induced and simulate primary demyelinating disorders. Mitochondrial enzyme defects in particular may present with stroke-like appearances. In many of these conditions, diagnosis is biochemical, but imaging has a significant role in suggesting the diagnosis, and documenting progression, response to therapy or complications.     

The relationship between cerebral white matter changes, mental function and blood pressure in normal elderly

The authors examined the relationship between cerebral white matter changes and mental function, blood pressure in 39 neurologically normal aged (21 males, 18 females, mean age 75.0 years) who had no latent lesions on MRI images. The severity of cerebral white matter changes was estimated by T1 value images on MRI and was measured in the bilateral frontal lobe on an axial slice at the level of the basal ganglia and in the bilateral anterior, middle, and posterior portions on axial slices at the level of the body of the lateral ventricle. Mental function was measured by the Hasegawa's dementia rating scale (HDS) and Kohs' block design test (Kohs' test). The severity of cerebral frontal white matter changes increased significantly with age (p less than 0.05). However there was no significant correlation between the severity of cerebral white matter changes and HDS, Kohs' test. The severity of frontal white matter changes correlated with the mean arterial blood pressure (p less than 0.02). These results suggest that the severity of cerebral white matter changes is not related with mental function in the normal elderly, and that the severity of frontal white matter lesions is related with mean arterial blood pressure.     

Brain MRI in patients with acute confusional state of diffuse psychiatric/neuropsychological syndromes in systemic lupus erythematosus

Objective: The objective of this study is to explore the characteristics of brain MRI abnormalities in acute confusional state (ACS) in neuropsychiatric systemic lupus erythematosus (NPSLE).

Methods: Thirty-six patients with ACS admitted to our institutions from 1992 to 2015 were exhaustively enrolled. Their medical charts and brain MRI scans were reviewed.

Results: Eighteen of 36 ACS patients had MRI abnormalities, mostly high-intensity lesions of various sizes in the cerebral white matter. MRI abnormalities improved after treatment in 12 of 14 patients in follow-up studies. MRI abnormalities were not correlated with ages at the onset of ACS, disease durations of SLE, the presence of anti-DNA, anti-phospholipid or anti-ribosomal P antibodies, or IL-6 levels in sera or cerebrospinal fluid. Notably, MRI abnormalities were significantly associated with the presence of serum anti-Sm antibodies (p?=?0.0067). Finally, eight of the 18 patients with MRI abnormalities, but none of the other 18 patients without MRI abnormalities, died from active SLE. Thus, MRI abnormalities significantly increased the mortality in ACS (p?=?0.0013, HR =10.36 [95% CI: 2.487–43.19]).

Conclusion: These results demonstrate that patients with ACS with MRI abnormalities have more severe diseases, resulting in poorer prognoses. The data also indicate that anti-Sm is involved in the development of MRI abnormalities in ACS.     

Abnormal regional cerebral blood flow on 99mTc ECD brain SPECT in patients with primary Sjögren's syndrome and normal findings on brain magnetic resonance imaging

Objective: Technetium-99m ethyl cysteinate dimer (^99mTc ECD) single photon emission computed tomography (SPECT) of the brain was used to detect abnormal regional cerebral blood flow (rCBF) in patients with primary Sjögren''s syndrome (pSS) and normal findings on brain magnetic resonance imaging (MRI). Methods: ^99mTc ECD brain SPECT was performed to detect brain lesions showing hypoperfusion in 32 female patients with pSS and definite neuropsychiatric symptoms or signs. Seventeen female patients with pSS without neuropsychiatric symptoms and signs were included as a control group for comparison. All of the 49 patients with pSS had normal findings on brain MRI. Results: ^99mTc ECD brain SPECT showed brain regions with hypoperfusion in 18 (56.3%) of the 32 patients, and parietal lobes were the most common areas with such lesions. By contrast, ^99mTc ECD brain SPECT showed brain regions with hypoperfusion in only three (17.6%) of the 17 patients with pSS without neuropsychiatric symptoms or signs. Conclusion: This study suggests that ^99mTc ECD SPECT is a sensitive tool for detecting regions of hypoperfusion in the brains of patients with pSS and neuropsychiatric symptoms or signs and normal findings on brain MRI. However, a review of the literature showed that the ^99mTc ECD SPECT findings in patients with pSS were non-specific.     

Clinical value of abnormal findings on brain magnetic resonance imaging in patients with intravascular large B-cell lymphoma

To investigate the prevalence and clinical value of abnormal findings detected via brain magnetic resonance imaging (MRI) in patients with intravascular large B-cell lymphoma (IVLBCL), we identified 33 patients with IVLBCL pathologically diagnosed and evaluated with pretreatment brain MRI. Abnormal findings on brain MRI were categorized into four patterns: (1) hyperintense lesion in the pons on T2-weighted imaging (T2WI), (2) nonspecific white matter lesions, (3) infarct-like lesions, and (4) meningeal thickening and/or enhancement. Abnormal cerebral findings were detected in 29 patients (87.9%). Hyperintense lesion in the pons was the most common finding (n?=?19 (57.6%) patients), followed by nonspecific white matter lesions (n?=?14 (42.4%) patients), infarct-like lesions (n?=?8 (24.2%) patients), and meningeal thickening and/or enhancement (n?=?4 (12.1%) patients). Impaired consciousness was seen in most of the patients with infarct-like lesions (87.5%) but less frequently in patients with hyperintense lesion in the pons (47.4%). We reviewed brain MRI findings in 39 patients with diffuse large B cell lymphoma with central nervous system (CNS) involvement and/or high-risk extranodal lesions for CNS involvement as a control group. In contrast to the patients with IVLBCL, no patient had hyperintense lesion in the pons in the control group (P?<?0.001). Follow-up brain MRI revealed improvement of abnormal findings in most of the patients who responded to chemotherapy. This study highlighted the diagnostic implication of hyperintense lesion in the pons on T2WI and the clinical usefulness of pretreatment brain MRI in IVLBCL even in patients without impaired consciousness.     

Subclinical brain magnetic resonance imaging abnormalities predict physical functional decline in high-functioning older adults

OBJECTIVES: To determine whether severity of subclinical brain magnetic resonance imaging (MRI) abnormalities predicts incident self-reported physical impairment or rate of decline in motor performance. DESIGN: Longitudinal analysis, average follow-up time: 4.0 years. SETTING: Cardiovascular Health Study (CHS). PARTICIPANTS: CHS participants with modified Mini-Mental State Examination (3MS) score of 80 or greater, no self-reported disability, no history of stroke, and at least one assessment of mobility (n=2,450, mean age=74.4). MEASUREMENTS: Brain MRI abnormalities (ventricular enlargement, white matter hyperintensities, subcortical and basal ganglia small brain infarcts), self-reported physical impairment (difficulty walking half a mile or with one or more activities of daily living), and motor performance (gait speed, timed chair stand). RESULTS: After adjusting for demographics, cardiovascular risk factors, and diseases, risk of incident self-reported physical impairment was 35% greater for those with severe ventricular enlargement than for those with minimal ventricular enlargement, 22% greater for those with moderate white matter hyperintensities than for those with minimal white matter hyperintensities, and 26% greater for participants with at least one brain infarct than for those with no infarcts. Those with moderate to severe brain abnormalities experienced faster gait speed decline (0.02 m/s per year) than those with no MRI abnormalities (0.01 m/s per year). Further adjustment for incident stroke, incident dementia, and 3MS score did not substantially attenuate hazard ratios for incident self-reported physical impairment or coefficients for decline in gait speed. CONCLUSION: Subclinical structural brain abnormalities in high-functioning older adults can increase the risk of developing physical disabilities and declining in motor performance.     

Characterization of White Matter Microstructure in Fetal Alcohol Spectrum Disorders

Background:  Exposure to alcohol during gestation is associated with CNS alterations, cognitive deficits, and behavior problems. This study investigated microstructural aspects of putative white matter abnormalities following prenatal alcohol exposure.
Methods:  Diffusion tensor imaging was used to assess white matter microstructure in 27 youth (age range: 8 to 18 years) with ( n  = 15) and without ( n  = 12) histories of heavy prenatal alcohol exposure. Voxelwise analyses, corrected for multiple comparisons, compared fractional anisotropy (FA) and mean diffusivity (MD) between groups, throughout the cerebrum.
Results:  Prenatal alcohol exposure was associated with low FA in multiple cerebral areas, including the body of the corpus callosum and white matter innervating bilateral medial frontal and occipital lobes. Fewer between-group differences in MD were observed.
Conclusions:  These data provide an account of cerebral white matter microstructural integrity in fetal alcohol spectrum disorders and support extant literature showing that white matter is a target of alcohol teratogenesis. The white matter anomalies characterized in this study may relate to the neurobehavioral sequelae associated with gestational alcohol exposure, especially in areas of executive dysfunction and visual processing deficits.     

DTI Study of Cerebral Normal-Appearing White Matter in Hereditary Neuropathy With Liability to Pressure Palsies (HNPP)

The majority of previous studies on hereditary neuropathy with liability to pressure palsies (HNPP) were focused on peripheral nerves, whereas cerebral alterations in HNPP have been less attended to. In this work, Diffusion tensor imaging (DTI) was used to detect the changes in WM, especially in the normal-appearing white matter (NAWM) in HNPP patients for its sensitivity in probing the microstructure of WM, the sensitive metric was searched for probing cerebral alterations and the regional distribution of cerebral abnormalities was identified. Twelve HNPP patients and 12 age- and gender-matched healthy controls underwent the conventional MRI, DTI scan, and electrophysiological examination. The conventional MRI images were first analyzed to identify abnormal intense regions and the NAWM regions. NAWM refers to the white matter regions that do not include the lesions on conventional MRI. The apparent diffusion coefficient and fractional anisotropy (FA) values of the NAWM were then measured and compared between patient and control groups. The sensitivity and specificity of 3 methods and the cerebral regional distribution of MR signal abnormalities were further analyzed. Hyperintense foci were observed on T2 weighted image and fluid attenuated inversion recovery images in 6 patients. Compared to the controls, FA values of the patients were significantly lower in bilateral frontal, orbitofrontal, and temporal NAWMs; whereas the electrophysiological examination results of patients and controls exhibited no statistically significant difference. The sensitivity of FA value was higher than that of electrophysiological examination and conventional MRI. The majority of abnormal signals on conventional MRI images and abnormal FA values were located in the frontal and temporal lobes. The results of our study show cerebral WM changes in HNPP patients. FA value in DTI has been shown to be sensitive to the cerebral microstructural changes in HNPP. The frontal lobe is the predilection site that is most involved in HNPP.     

A case of systemic lupus erythematosus with extensive brain stem involvement

Systemic lupus erythematosus (SLE) is a multisystem, autoimmune connective tissue disorder. Neuropsychiatric SLE (NPSLE) has varied clinical and radiological manifestations. Clinical manifestations range from subtle abnormalities of neurocognitive functions and mood changes to overt psychiatric or neurological manifestations such as seizures, stroke, and psychosis. Magnetic resonance imaging (MRI) may show various types of abnormalities. Cerebral white matter lesions are most common (60–86%). Here, we are discussing a young female who presented with alteration of sensorium and right-sided hemiparesis, and MRI of the brain showed extensive involvement of brainstem in the form of possible demyelination.     

A case of systemic lupus erythematosus with extensive brain stem involvement

Systemic lupus erythematosus (SLE) is a multisystem, autoimmune connective tissue disorder. Neuropsychiatric SLE (NPSLE) has varied clinical and radiological manifestations. Clinical manifestations range from subtle abnormalities of neurocognitive functions and mood changes to overt psychiatric or neurological manifestations such as seizures, stroke, and psychosis. Magnetic resonance imaging (MRI) may show various types of abnormalities. Cerebral white matter lesions are most common (60–86%). Here, we are discussing a young female who presented with alteration of sensorium and right-sided hemiparesis, and MRI of the brain showed extensive involvement of brainstem in the form of possible demyelination.     

Neurological Manifestations in Parry–Romberg Syndrome: 2 Case Reports

Parry–Romberg syndrome (PRS) is a variant of morphea usually characterized by a slowly progressive course. Clinical and radiological involvement of the central nervous system may be observed in PRS.We describe 2 patients with PRS and neurological symptoms (one with trigeminal neuralgia associated with deafness, and the second with hemifacial pain associated with migraine without aura) in conjunction with abnormal cerebral MRI including white matter T2 hyperintensities and enhancement with gadolinium. Despite the absence of specific immunosuppressive treatments, both patients have presented stable imaging during follow-up without any clinical neurologic progression. We have performed a large review of the medical literature on patients with PRS and neurological involvement (total of 129 patients)Central nervous system involvement is frequent among PRS patients and is inconsistently associated with clinical abnormalities. These various neurological manifestations include seizures, headaches, movement disorders, neuropsychological symptoms, and focal symptoms. Cerebral MRI may reveal frequent abnormalities, which can be bilateral or more often homolateral to the skin lesions, localized or so widespread so as to involve the whole hemisphere: T2 hyperintensities, mostly in the subcortical white matter, gadolinium enhancement, brain atrophy, and calcifications. These radiological lesions do not usually progress over time. Steroids or immunosuppressive treatments are controversial since it remains unclear to what extent they are beneficial and there is often no neurological progression.