Correlation of evoked potential and MRI findings in Wilson's disease

A weighted cranial diffusion-weighted imaging scale for Wilson's disease

Objectives

Cranial magnetic resonance imaging (MRI) could be a crucial tool for the assessment for neurological symptoms in patients with Wilson's disease (WD). Diffusion-weighted imaging (DWI) hyperintensity reflects the acute brain injuries, which mainly occur in specific brain regions. Therefore, this study aimed to develop a weighted cranial DWI scale for patients with WD, with special focus on specific brain regions.

Materials and methods

In total, 123 patients with WD were enrolled, 118 of whom underwent 1.5 T-MRI on admission. The imaging score was calculated as described previously and depended on the following sequences: one point was acquired when abnormal intensity occurred in the T1, T2, and fluid-attenuation inversion recovery sequences, and two points were acquired when DWI hyperintensity were found. Consensus weighting was conducted based on the symptoms and response to treatment.

Results

Intra-rater agreement were good (r = 0.855 [0.798-0.897], p < 0.0001). DWI hyperintensity in the putamen was a high-risk factor for deterioration during de-copper therapy (OR = 8.656, p < 0.05). The high-risk factors for readmission for intravenous de-copper therapies were DWI hyperintensity in the midbrain (OR = 3.818, p < 0.05) and the corpus callosum (OR = 2.654, p < 0.05). Both scoring systems had positive correlation with UWDRS scale (original semi-quantitative scoring system, r = 0.35, p < 0.001; consensus semi-quantitative scoring system, r = 0.351, p < 0.001.). Compared to the original scoring system, the consensus scoring system had higher correlations with the occurrence of deterioration (OR = 1.052, 95%CI [1.003, 1.0103], p < 0.05) and readmission for intravenous de-copper therapy (OR = 1.043, 95%CI [1.001, 1.086], p < 0.05).

Conclusion

The predictive performance of the consensus semi-quantitative scoring system for cranial MRI was improved to guide medication, healthcare management, and prognosis prediction in patients with WD. For every point increase in the neuroimaging score, the risk of exacerbations during treatment increased by 5.2%, and the risk of readmission to the hospital within 6 months increased by 4.3%.

Brainstem auditory evoked responses in children living at high altitude in the andes mountains

OBJECTIVES

This neurophysiological study compared brainstem auditory evoked responses (BAER) in children living at high elevations (2800 to 3000 meters) in the Andes Mountains of Ecuador with a reference group of children living at sea level in the U.S.

METHODS

BAER absolute latencies of waves I through V; interpeak latencies I-III, III-V, and I-V; amplitudes of waves I and V; and the V/I amplitude ratio were measured by scalp electrodes at acoustic click stimulus rates of 10 and 50 pulses per second (pps).

RESULTS

Statistical analysis showed that the high-altitude group had significantly longer absolute and interpeak BAER latencies than the sea-level reference group at both the 10 and 50 pps stimulus rates for most wave peaks. The amplitudes of waves I and V were significantly reduced for the high-altitude group at 10 and 50 pps, suggesting blood O2 saturation effects.

CONCLUSIONS

The BAER of children in the high-altitude group suggested physiological anomalies in auditory neural conduction and summation compared with the sea-level group. The results further suggest that small physiological effects of altitude on BAER, especially at elevations near 3000 meters and higher, should be taken into consideration in the evaluation of brainstem auditory function.

Wilson's disease

In the almost 100 years since Wilson's description of the illness that now bears his name, tremendous advances have been made in our understanding of this disorder. The genetic basis for Wilson's disease - mutation within the ATP7B gene - has been identified. The pathophysiologic basis for the damage resulting from the inability to excrete copper via the biliary system with its consequent gradual accumulation, first in the liver and ultimately in the brain and other organs and tissues, is now known. This has led to the development of effective diagnostic and treatment modalities that, although they may not eliminate the disorder, do provide the means for efficient diagnosis and effective amelioration if carried out in a dedicated and persistent fashion. Nevertheless, Wilson's disease remains both a diagnostic and treatment challenge for physician and patient. Its protean clinical manifestations make diagnosis difficult. Appropriate diagnostic evaluations to confirm the diagnosis and institute treatment can be confusing. In this chapter, the clinical manifestations, diagnostic evaluation, and treatment approaches for Wilson's disease are discussed.

Do MRI features distinguish Wilson's disease from other early onset extrapyramidal disorders? An analysis of 100 cases

Magnetic resonance imaging (MRI) is frequently used in the evaluation of various extrapyramidal disorders. Among the plethora of MRI features in Wilson's disease (WD), only "face of the giant panda" sign has been recognized to distinguish WD from other early onset extrapyramidal disorders (EOEPD). To ascertain the value of various MRI features in differentiating neuropsychiatric form of WD from other EOEPD. This retrospective analysis included 100 patients (M:F = 56:44) of EOEPD (5-40 years), who had undergone MRI during Jan'03 to Nov'08. Their clinical features were recorded and the following MR sequences were analyzed: T1WI, T2WI, FLAIR. Fifty-six patients had WD (M:F = 28:30, age at onset: 14 +/- 6.8 years) and 44 had other EOEPD (M:F = 27:17, age at onset: 19 +/- 9.8 years) that included Huntington's disease--4, young-onset Parkinson's disease--7, mitochondrial disorders--2, Hallervorden-Spatz disease--8, non-Wilsonian hepatolenticular degeneration--2, toxic/metabolic disorder--1, and others--20. The duration of illness at the time of MRI was comparable (WD: 3.1 +/- 4.9 years; Other EOEPD: 2.8 +/- 2.4 years). MR signal characteristics varied in topography and severity in both the groups. All the patients of WD had signal abnormalities in MRI, as against 16/44 of the other EOEPD group. The following MR observations were noted exclusively in WD: "Face of giant panda" sign (14.3%), tectal plate hyperintensity (75%), central pontine myelinolysis (CPM)-like abnormalities (62.5%), and concurrent signal changes in basal ganglia, thalamus, and brainstem (55.3%). Besides "Face of giant panda" sign, hyperintensities in tectal-plate and central pons (CPM-like), and simultaneous involvement of basal ganglia, thalamus, and brainstem are virtually pathognomonic of WD.

Central Pontine Signal Changes in Wilson's Disease: Distinct MRI Morphology and Sequential Changes with De-Coppering Therapy

BACKGROUND AND PURPOSE

Reports of central pontine myelinolysis (CPM)-like changes in Wilson's disease (WD) and its sequential changes are exceptional. The aim was to study the MRI characteristics of CPM-like changes in WD and the serial changes.

METHODS

Among the 121 patients of WD, twenty (M:F:9:11, age at onset: 14.2 +/- 4.6 years) had features similar to CPM. All had progressive neuropsychiatric form of WD. All except five were on de-coppering treatment. None had acute deterioration or hepatic failure. Ten patients underwent repeat studies.

RESULTS

Twenty patients with CPM-like changes manifested with characteristic phenotype of WD. Three distinct patterns of CPM-like changes were observed: (a) characteristic round shape -7, (b) "bisected" -9, and (c) "trisected" -4. Only one had signal changes suggesting extra-pontine myelinolysis. All patients had contiguous involvement of midbrain. Serial MRI evaluation in 10 patients, at mean interval period of 17.4 +/- 13.2 months, revealed complete reversal in one, partial improvement in five, and no change in three. Clinical and MRI improvement occurred pari passu, except in one.

CONCLUSIONS

CPM-like changes in WD are perhaps under-recognized and are distinct from the commonly known "osmotic demyelination." It is potentially reversible similar to other MRI features of WD.

Sequential MRI changes in Wilson's disease with de-coppering therapy: a study of 50 patients

Wilson's disease (WD) is clinically and radiologically a dynamic disorder. However, there is a paucity of studies involving sequential MRI changes in this disease with or without therapy This study looked at serial MRI changes and their clinical correlate in patients with WD The severity of MRI changes using 1.5 T MRI in 50 patients with WD was graded based on alteration in signal intensity of focal lesions and atrophy. Details of clinical manifestations, Schwab and England Activities of daily living (MSEADL) score, Neurological Symptom Score (NSS) and Chu staging were recorded. Clinical severity and disability scores were correlated with MRI scores using SPSS v10 The mean age at onset of illness and diagnosis was 12.8+/-5.6 years and 14.4+/-6.0 years, respectively. At the time of first MRI, patients had been treated for 49.0+/-77.3 months. At a follow-up of 24.2+/-12.2 months, clinically 36 patients had improved, 9 remained the same and 5 had worsened. Serial imaging revealed an improvement in MRI parameters in 35 patients, no significant changes in 10, worsening in 4 and an admixture of resolving and evolving changes in 1. The overall MRI score improved from 8.2+/-5.7 to 5.9+/-6.6. There was an improvement in measures of disability and impairment in all: Chu stage, 11.5+/-0.7 to 1.3+/-0.6; MSEADL score (%), 79.7+/-27.6 to 88.0+/-25.4; NSS, 10.6+/-11.2 to 8.0+/-11.6, with good clinico-radiological correlation. Patients with extensive changes, white-matter involvement and severe diffuse atrophy had a poor prognosis In conclusion, the majority of patients with WD showed variable improvement in clinical and MRI features when treated.

A study of clinical, MRI and multimodality evoked potentials in neurologic Wilson disease

The aims of this study were evaluate motor, somatosensory, visual and auditory brainstem evoked potential (MEP, SEP, VEP, ABER) changes in Wilson disease (WD) and correlate these with magnetic resonance imaging (MRI) and clinical findings. Neurologic WD diagnosed on the basis of clinical, ceruloplasmin and Kayser-Fleischer ring were evaluated including pedigree charting, hepatic, renal, hematologic and osteoarticular manifestations. Blood counts, serum chemistry, MRI, MEP to tibialis anterior, tibial SEP, VEP and ABER were performed. Evoked potential (EP) changes were correlated with clinical and MRI findings. Eighteen WD patients were recruited from 17 families whose mean age was 16 years. Movement disorders were present in 14, cognitive decline in 12 and pyramidal signs in 12 patients. MRI revealed involvement of basal ganglia in 80%, thalamus in 40%, brain stem in 46.7% and subcortical white matter in 53.3%. MEP was abnormal in 35.7%, SEP in 30.8%, VEP in 57% and ABER in 61.5% patients; the latter three EP changes were subclinical. Frequency and number of EP abnormalities were higher with increasing severity of illness. SEP, VEP and ABER reveals subclinical abnormality and MEP helps in documenting both clinical and subclinical abnormalities. Number of EP abnormalities increases with increasing clinical severity of WD.

Wilson’s disease: cranial MRI observations and clinical correlation

INTRODUCTION

Study of MRI changes may be useful in diagnosis, prognosis and better understanding of the pathophysiology of Wilson's disease (WD). We aimed to describe and correlate the MRI abnormalities of the brain with clinical features in WD.

METHODS

MRI evaluation was carried out in 100 patients (57 males, 43 females; mean age 19.3+/-8.9 years) using standard protocols. All but 18 patients were on de-coppering agents. Their history, clinical manifestations and scores for severity of disease were noted.

RESULTS

The mean duration of illness and treatment were 8.3+/-10.8 years and 7.5+/-7.1 years respectively. MRI of the brain was abnormal in all the 93 symptomatic patients. The most conspicuous observations were atrophy of the cerebrum (70%), brainstem (66%) and cerebellum (52%). Signal abnormalities were also noted: putamen (72%), caudate (61%), thalami (58%), midbrain (49%), pons (20%), cerebral white matter (25%), cortex (9%), medulla (12%) and cerebellum (10%). The characteristic T2-W globus pallidal hypointensity (34%), "Face of giant panda" sign (12%), T1-W striatal hyperintensity (6%), central pontine myelinosis (7%), and bright claustral sign (4%) were also detected. MRI changes correlated with disease severity scores (P<0.001) but did not correlate with the duration of illness.

CONCLUSION

MRI changes were universal but diverse and involved almost all the structures of the brain in symptomatic patients. A fair correlation between MRI observations and various clinical features provides an explanation for the protean manifestations of the disease.

Evoked potentials in children with Wilson's disease

We assessed multimodal evoked potentials (EPs) in 13 children with newly diagnosed neurologically symptomatic Wilson's disease (WD) and in their first degree symptom-free relatives, consisting of seven presymptomatic and 15 asymptomatic siblings and 22 asymptomatic parents. EP abnormalities of at least one modality and one side stimulation were observed in 38.5% of patients, 42.9% of presymptomatic siblings, 21.4% of asymptomatic siblings and 18.2% of parents. Patients tended to have more prolonged central latencies of EPs. However, the left I-V interpeak brainstem auditory EP latency difference was the only one to reach at the statistical significance (P = 0.001). Abnormal VEP P100 latency was detected more frequently in presymptomatic siblings than those in asymptomatic ones (42.9% vs 7.1%, P = 0.049). In all relatives, other diagnostic tests including electroencephalography, electromyography and head magnetic resonance imaging (MRI) for subclinical nervous system involvement and Kayser-Fleischer rings examination yielded normal results. In pre/asymptomatic siblings, genetic and biochemical studies may aid to initiate treatment prior to the development of permanent tissue damage. Our results indicate that abnormal EPs may signal unique pathological finding in some subjects. Importantly, these abnormalities occur earlier than Kayser-Fleischer rings and MRI lesions. In early stages of WD, EP recordings may, therefore, be used to help decide on treatment initiation and treatment efficacy evaluation. Moreover, EP recordings can readily be added to family screening studies.

Comparison of MRI, EEG, EPs and ECD-SPECT in Wilson's disease

OBJECTIVES

The purpose of this study is to evaluate the efficiency of a few methodologies in detecting anatomo-functional brain abnormalities in patients with Wilson's disease.

MATERIALS AND METHODS

Twenty-three patients with Wilson's disease underwent almost simultaneously brain magnetic resonance imaging (MRI), computerized electroencephalography (EEG), multimodal evoked potentials (EPs) and ECD single photon computerized tomography (SPECT) evaluation. The clinical picture was of the neurologic type in 8 patients and of the hepatic type in 15.

RESULTS

MRI was abnormal in 7 patients with neurological manifestations. The EPs proved pathologic in 7 neurologically symptomatic patients and in 4 cases with hepatic form. These results agree with those reported in other case studies. The EEG records were abnormal only in 3 cases. Nevertheless, the most interesting finding of this study is the particular frequency (86%) of diffuse or focal decrease of ECD uptake shown by brain SPECT.

CONCLUSION

We highlight the use of this interesting procedure in the therapeutic monitoring of this disease.

Neurological impairment and recovery in Wilson's disease: evidence from PET and MRI

We studied the relationship of regional cerebral glucose consumption (rCMRGlc) and striatal dopamine D2 receptor binding as assessed with positron emission tomography (PET) with the structural abnormalities of the brain in magnetic resonance images (MR), and the degree of neurological impairment in 18 patients with Wilson's disease (WD). The rCMRGlc was determined in the basal ganglia, the thalamus, the cerebral cortex, and the cerebellar hemispheres. The severity of neurological signs, defined by semiquantitative motor impairment scores, correlated highly (r = -0.80) with the reduction of striatal rCMRGlc. Clinical scores, striatal rCMRGlc, and the degree of MRI abnormalities showed no correlation with different indices of dopamine D2 receptor binding. Sequential PET measurements in three patients during treatment with chelating agents revealed a moderate increase of striatal rCMRGlc (in two patients) and a moderate to marked increase of striatal D2 receptor binding (in three patients) in association with clinical improvement. Our data suggest that the rCMRGlc represents a sensitive and objective measure for assessing and monitoring striatal and extrastriatal involvement in WD. The lack of correlation between the dopamine D2 receptor binding and striatal rCMRGlc and structural abnormalities may be explained by the wide spectrum of clinical manifestations and different responses to treatment in WD patients.

Case report: concordant traumatic brainstem contusion delayed diagnosis in a young man with Wilson's disease

Wilson's disease is a hereditary autosomal recessive disorder of copper metabolism. The corresponding gene locus has been localized on the long arm of chromosome 13. Three different clinical variants of the disease can be distinguished: hepato-cerebral, abdominal/hepatic, and central nervous type. The heterogeneity of symptoms can cause problems in differential diagnosis, especially when another concordant disorder can also explain the pathogenesis of symptoms. The case report of a young man who suffered from brainstem contusion demonstrates the possibilities of misinterpretation because presenting symptoms could be attributed either to traumatic brain injury followed by adjustment disorder or Wilson's disease. Clinical signs included leftsided hemiparesis, bilateral gaze direction nystagmus, marked dysarthria with consecutive pervasive mutism, choreo-athetoid movements, spasmodic torticollis and diplopia dependent on gaze direction. Slit lamp examination showed Kayser-Fleischer's corneal ring. EEG- and computer assisted tomography investigations revealed non-specific findings. The patient was treated with D-Penicillamine. Alternative treatment with oral zinc preparations is discussed.