Neurological presentation of Fabry's disease in a 52 year old man

Pathogenesis and Molecular Mechanisms of Anderson-Fabry Disease and Possible New Molecular Addressed Therapeutic Strategies

Anderson-Fabry disease (AFD) is a rare disease with an incidenceof approximately 1:117,000 male births. Lysosomal accumulation of globotriaosylceramide (Gb3) is the element characterizing Fabry disease due to a hereditary deficiency α-galactosidase A (GLA) enzyme. The accumulation of Gb3 causes lysosomal dysfunction that compromises cell signaling pathways. Deposition of sphingolipids occurs in the autonomic nervous system, dorsal root ganglia, kidney epithelial cells, vascular system cells, and myocardial cells, resulting in organ failure. This manuscript will review the molecular pathogenetic pathways involved in Anderson-Fabry disease and in its organ damage. Some studies reported that inhibition of mitochondrial function and energy metabolism plays a significant role in AFD cardiomyopathy and in kidney disease of AFD patients. Furthermore, mitochondrial dysfunction has been reported as linked to the dysregulation of the autophagy-lysosomal pathway which inhibits the mechanistic target of rapamycin kinase (mTOR) mediated control of mitochondrial metabolism in AFD cells. Cerebrovascular complications due to AFD are caused by cerebral micro vessel stenosis. These are caused by wall thickening resulting from the intramural accumulation of glycolipids, luminal occlusion or thrombosis. Other pathogenetic mechanisms involved in organ damage linked to Gb3 accumulation are endocytosis and lysosomal degradation of endothelial calcium-activated intermediate-conductance potassium ion channel 3.1 (KCa3.1) via a clathrin-dependent process. This process represents a crucial event in endothelial dysfunction. Several studies have identified the deacylated form of Gb3, globotriaosylsphingosine (Lyso-Gb3), as the main catabolite that increases in plasma and urine in patients with AFD. The mean concentrations of Gb3 in all organs and plasma of Galactosidase A knockout mice were significantly higher than those of wild-type mice. The distributions of Gb3 isoforms vary from organ to organ. Various Gb3 isoforms were observed mainly in the kidneys, and kidney-specific Gb3 isoforms were hydroxylated. Furthermore, the action of Gb3 on the KCa3.1 channel suggests a possible contribution of this interaction to the Fabry disease process, as this channel is expressed in various cells, including endothelial cells, fibroblasts, smooth muscle cells in proliferation, microglia, and lymphocytes. These molecular pathways could be considered a potential therapeutic target to correct the enzyme in addition to the traditional enzyme replacement therapies (ERT) or drug chaperone therapy.

[Fabry's disease: Neurological disorders]

The paper considers the pathogenesis and clinical features of Fabry's disease. It is stressed that along with cardiovascular system damage and kidney injury, there are peripheral and central nervous system lesions in this disease. In Fabry's disease, great attention is paid to cerebrovascular diseases that frequently give rise to disability. Peripheral neuropathy is mainly due to involvement of minor fibers and autonomic disorders. Signs that allow this disease to be diagnosed are given.

Cognitive dysfunction and depression in Fabry disease: a systematic review

BACKGROUND

Fabry disease, an X-linked lysosomal storage disorder, leads to multi-organ dysfunction, including cerebrovascular disease and psychological disorders. However, the prevalence and pattern of associated cognitive dysfunction is not well understood.

OBJECTIVES

To investigate whether there is reliable evidence for neuropsychological impairment in patients with Fabry disease and which cognitive domains are affected. To estimate the prevalence of and factors associated with depression in patients with Fabry disease.

METHOD

Qualitative systematic review of the literature of studies conducting neuropsychological assessment or measuring the prevalence of depression in adults with Fabry disease using the preferred reporting items for systematic reviews and meta-analysis (PRISMA) guidelines where appropriate.

RESULTS

There is some evidence for neuropsychological impairment in Fabry disease in executive functioning, information processing speed and attention, with preservation of: general intellectual functioning, memory, naming, perceptual functioning and global cognitive functioning. Prevalence rates of depression in Fabry disease ranged from 15% to 62%, with the largest study to date reporting a prevalence rate of 46%. The most common factor associated with depression was neuropathic pain, both directly and indirectly by affecting social and adaptive functioning.

CONCLUSION

Our review suggests that Fabry disease may be associated with a characteristic pattern of cognitive deficits and a high prevalence of psychological disorders such as depression but highlights the limited available data. Exploring the nature of cognitive impairment in Fabry disease using standardised neuropsychological assessment, brain imaging and measures of depression is an important task for future research.

Neuropsychiatric symptoms and brain structural alterations in Fabry disease

BACKGROUND

Neuropsychiatric symptoms (NPS), mainly cognitive deficits up to dementia and depressive syndromes have been described repeatedly in Fabry disease (FD). However, examinations regarding the pattern, extent, and frequency of the NPS in FD are still lacking. Moreover, the relationship between NPS and brain structural alterations in FD is unknown. The aim of this study was 1) to characterize NPS in a relatively large cohort of adult subjects with FD, and 2) to explore the association of cognitive performance and depressive syndromes with the FD-typical brain structural findings.

METHODS

Twenty-five Fabry patients (age 36.5 ± 11.0) with mild to moderate disease involvement and 20 age, gender-, and education-matched healthy controls were extensively studied by neuropsychiatric assessment, structural magnetic resonance imaging, magnetic resonance angiography, and diffusion-tensor imaging.

RESULTS

Patients with FD showed deficits only in the attention domain. Clinically relevant depressive syndromes were noted in 60% of the patients. The subgroup of patients with markedly elevated volumes of white matter lesions (not associated with actual stroke; n=7) showed slightly more learning and memory deficits, but no higher depression rate compared to less affected patients.

CONCLUSIONS

Against the prevailing assumption, Fabry patients, even those with marked brain structural alterations, showed only mild cognitive deficits. The high frequency of depression in FD is likely to be related to the burden of this chronic multiorganic hereditary disease, but not to the FD-typical brain structural alterations. Longitudinal studies are necessary to clear, if the mild cognitive deficits in FD might precede clinically relevant cognitive decline.

Psychiatric and cognitive profile in Anderson-Fabry patients: a preliminary study

Anderson-Fabry disease (AFD) is an X-linked inherited lysosomal storage disorder disease caused by a deficiency in the activity of the alpha-galactosidase enzyme. We investigated neuropsychological and psychiatric function in AFD patients. We studied 16 AFD patients, aged 7 to 61 years. Intelligence, language, vision-spatial abilities, memory, sensorimotor abilities, and attention and executive functions were tested with a computerized test battery as well as standard paper and pencil tests. The results were compared to known age-based norms. In addition, all patients were screened for lifelong DSM-IV Axis-I and Axis-II psychiatric diagnoses, and 4 were interviewed by a psychiatrist. Performance on most cognitive measures was within average range. All measures of information processing speed were significantly reduced, as were some measures of executive functions. Ten out of 16 patients met DSM-IV criteria for Axis I or Axis II diagnoses at some point in their lives. This preliminary study delineates a psychiatric and cognitive phenotype in AFD patients and contributes to the growing field of characterizing behavioral phenotypes of patients with genetic diseases. We suggest that psychiatric and neuro-psychological evaluation be included in the patient's evaluation.

An autopsy case of Fabry disease with neuropathological investigation of the pathogenesis of associated dementia

The pathogenesis of dementia associated with Fabry disease was examined neuropathologically in an autopsy case. The patient was a 47-year-old computer programmer who developed renal failure at the age of 36, necessitating peritoneal dialysis, and thereafter suffered in succession episodic pulmonary congestion, bradyacusia, heart failure, and dementia, before dying of acute myocardial infarction. MRI of the brain demonstrated leuko-araiosis. The CNS parenchyma showed widespread segmental hydropic swelling of axons in the bilateral cerebral and cerebellar deep white matter in addition to neuronal ballooning due to glycolipid storage in a few restricted nuclei and multiple tiny lacunae. Hydropic axonal swelling was also sparsely distributed in the pyramidal tract, pedunculus cerebellaris superior and brachium colliculi inferioris, but wallerian degeneration of these tracts was absent. Additional features included angiopathy of the subarachnoidal arteries due to Fabry disease, such as medial thickening resulting from glycolipid deposition in smooth muscle cells (SMCs) and adventitial fibrosis with lymphocytic infiltration, together with widespread subtotal or total replacement of medial SMCs by fibrosis, associated with prominent intimal fibrous thickening and undulation of the internal elastic membrane of medium-sized (1000-100 microm diameter) arteries. The findings in this case suggest that axonopathic leukoencephalopathy due to multisegmental hydropic swelling of axons in the bilateral cerebral deep white matter is responsible for the dementia associated with Fabry disease, and may be caused by ischemia resulting from widespread narrowing and stiffening of medium-sized subarachnoidal arteries and progressive heart failure.

MRI and the diagnosis of multiple sclerosis: expanding the concept of "no better explanation"

Although the diagnosis of multiple sclerosis relies on the demonstration of disease dissemination in space and time, the exclusion of other neurological disorders is also essential. The limited specificity of abnormalities disclosed by MRI may increase the likelihood of diagnosis of multiple sclerosis in patients affected by other disorders. The available criteria for diagnosis of multiple sclerosis have not taken advantage of the potential of MRI to detect features "not suggestive" of multiple sclerosis. Recognition of such features in the work-up of patients suspected of having multiple sclerosis may reduce the likelihood of a false positive diagnosis of the disorder in some, while suggesting the correct alternative diagnosis in other patients. On the basis of this, a workshop of the European MAGNIMS (Magnetic Resonance Network in Multiple Sclerosis) was held to define a series of MRI red flags in the setting of clinically suspected multiple sclerosis that is derived from evidence-based findings and educated guesses. The presence of such red flags should alert clinicians to reconsider the differential diagnosis more extensively. In this review we will report on the conclusions of this international consensus, which should represent a first step beyond the concept of "no better explanation", and inform future diagnostic criteria for multiple sclerosis.

Parkinsonism and Anderson Fabry's disease: a case report

We describe and present a videotape of a 57-year-old woman admitted to our Neurological Clinic at 46 years of age due to extrapyramidal manifestations suggesting Parkinson's disease (PD) and with a brain magnetic resonance imaging scan showing multi-infarctual leukoencephalopathy. Various investigations led to the diagnosis of Anderson Fabry's disease (AFD). We discuss the possibility of correlation between the patient's parkinsonism and AFD.

Genetics of cerebrovascular disorders

Physicians must be able to recognize stroke caused by a mendelian or mitochondrial disorder. Some genetic disorders such as sickle cell anemia and Fabry disease have proven disease-specific treatments, whereas others have no effective treatment, including cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) and mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes (MELAS). Proper diagnosis of a genetic disorder has prognostic value and prevents patient exposure to unnecessary and potentially harmful therapeutic agents and diagnostic tests. This article reviews the clinical and genetic features of some mendellan and mitochondrial disorders associated with ischemic stroke, hemorrhagic stroke, and cerebrovascular malformations.

Monitoring the 3-year efficacy of enzyme replacement therapy in fabry disease by repeated skin biopsies

The earliest clinical signs of Fabry disease often manifest as dermatologic disturbances such as angiokeratomata, hypohidrosis, acroparesthesias, and impaired thermal and vibration detection. These disturbances are caused by cellular globotriaosylceramide accumulation in the skin due to deficient lysosomal alpha-galactosidase A activity. In this histologic study, we analyzed pre- and post-treatment dermatologic biopsies from 58 Fabry patients enrolled in a 5 mo, Phase 3 double-blind, randomized, placebo-controlled trial followed by a 30 mo open label extension study of recombinant human alpha-galactosidase A (r-halphaGalA), administered i.v. at 1 mg per kg every 2 wk. Baseline evaluations revealed globotriaosylceramide in multiple dermal cell types (vascular endothelial cells, vascular smooth muscle cells, perineurium). Five months of r-halphaGalA treatment in the Phase 3 trial resulted in complete clearance of globotriaosylceramide from the superficial capillary endothelium in all treatment patients and in only 1 (3%) placebo patient (p<0.001). The placebo group achieved similar results after 6 mo of r-halphaGalA in the open label trial. The capillary endothelium remained free of globotriaosylceramide for up to 30 mo into the extension study among 39 of 40 (98%) patients who underwent biopsies. Globotriaosylceramide clearance from deep vascular endothelial cells was similarly robust. Vascular smooth muscle cells and perineurium demonstrated moderate clearance. These findings suggest that long-term treatment with r-halphaGalA may halt the progression of pathology and prevent the dermatologic disturbances in Fabry patients, and that periodic dermal biopsies can serve as a reliable monitor of sustained efficacy.

[Fabry's disease: new therapeutic options for this lysosomal storage disorder]

Fabry's disease is an x-linked, recessive, lysosomal storage disorder that results from deficient alpha-galactosidase A activity with pathological sphingolipid deposition mainly in endothelium, smooth muscle cells, kidneys, central and peripheral nervous system, and myocardium. Clinical manifestation mostly occurs during childhood and adolescence with severe pain attacks or chronic pain mainly in hands and feet, hypohydrosis, and skin lesions (angiokeratoma). In more advanced disease stages, renal and cerebrovascular complications develop with proteinuria and later renal failure and cerebral ischemia caused by cerebral microangiopathy, dilatative arteriopathy, or cardiac embolism. Heterozygote female carriers are severely affected more often than was previously considered. The diagnosis is based on the detection of deficient alpha-galactosidase A activity in leukocytes, fibroblasts, or tissue biopsies. Two randomised placebo-controlled studies showed that enzyme replacement is effective by demonstrating either reduced pain or reduced tissue sphingolipid deposition. Early diagnosis of Fabry's disease is important in view of these new causal therapeutic options.