Causally treatable, hereditary neuropathies in Fabry's disease, transthyretin-related familial amyloidosis, and Pompe's disease

OBJECTIVES

Most acquired neuropathies are treatable, whereas genetic neuropathies respond to treatment in Fabry's disease (FD), transthyretin-related familial amyloidosis (TTR-FA), and Pompe's disease (PD). This review summarizes and discusses recent findings and future perspectives concerning etiology, pathophysiology, clinical presentation, diagnosis, treatment, and outcome of neuropathy in FD, TTR-FA, and PD.

METHODS

Literature review.

RESULTS

Neuropathy in FD concerns particularly small, unmyelinated, or myelinated sensory fibers (small fiber neuropathy [SFN]) and autonomic fibers, manifesting as acroparesthesias, Fabry's crises, or autonomous disturbances. FD neuropathy benefits from agalsidase alpha (0.2 mg/kg every second week intravenously) or from beta (1.0 mg/kg every second week intravenously). Neuropathy in TTR-FA is axonal and affects large and small sensory, motor, and autonomous fibers. Neuropathy in TTR-FA profits from liver transplantation and the TTR kinetic stabilizer tafamidis (20 mg/d). Neuropathy in PD particularly occurs in late-onset PD and manifests as mononeuropathy, polyneuropathy, or SFN. PD neuropathy presumably responds to alglucosidase-alpha (20 mg/kg every second week intravenously).

CONCLUSIONS

Neuropathy in FD, TTR-FA, and PD is predominantly a SFN and can be the dominant feature in FD and TTR-FA. SFN in FD, TTR-FA, and PD needs to be recognized and benefits from enzyme replacement treatment or TT-kinetic stabilizers.

Secondary myopathy due to systemic diseases

Background

Some systemic diseases also affect the skeletal muscle to various degrees and with different manifestations. This review aimed at summarizing and discussing recent advances concerning the management of muscle disease in systemic diseases.

Method

Literature review by search of MEDLINE, and Current Contents with appropriate search terms.

Results

Secondary muscle disease occurs in infectious disease, endocrine disorders, metabolic disorders, immunological disease, vascular diseases, hematological disorders, and malignancies. Muscle manifestations in these categories include pathogen‐caused myositis, muscle infarction, rhabdomyolysis, myasthenia, immune‐mediated myositis, necrotising myopathy, or vasculitis‐associated myopathy. Muscle affection may concern only a single muscle, a group of muscles, or the entire musculature. Severity of muscle affection may be transient or permanent, may be a minor part of or may dominate the clinical picture, or may be mild or severe, requiring invasive measures including artificial ventilation if the respiratory muscles are additionally involved. Diagnostic work‐up is similar to that of primary myopathies by application of non‐invasive and invasive techniques. Treatment of muscle involvement in systemic diseases is based on elimination of the underlying cause and supportive measures. The prognosis is usually fair if the causative disorder is effectively treatable but can be fatal in single cases if the entire musculature including the respiratory muscles is involved, in case of infection, or in case of severe rhabdomyolysis.

Conclusion

Secondary muscle manifestations of systemic diseases must be addressed and appropriately managed. Prognosis of secondary muscle disease in systemic diseases is usually fair if the underlying condition is accessible to treatment.

Increased frequencies of serum antibodies to neurofilament light in patients with primary chronic progressive multiple sclerosis

We investigated whether serum and cerebrospinal fluid (CSF) antibodies to the light subunit of the NF protein (NF-L), a main component of the axonal cytoskeleton, may serve as biological markers for axonal pathology and/or disease progression in multiple sclerosis (MS). IgG to NF-L was measured in sera and CSF of MS patients, patients with inflammatory demyelinating diseases of the PNS, with acute inflammatory neurological diseases (including bacterial and viral meningitis), with neurodegenerative diseases, with acute noninflammatory neurological diseases (including stroke, headache and backache) and healthy controls by enzyme-linked immunosorbent assay. We found that serum anti-NF-L IgG antibodies were significantly elevated in MS patients with primary progressive disease course and we provide evidence for an intrathecal production of these antibodies. Our findings support the use of serum antibodies to NF-L as a marker for axonal destruction.

Iatrogenic lesions of peripheral nerves

Iatrogenic nerve lesions (INLs) are an integral part of peripheral neurology and require dedicated neurologists to manage them. INLs of peripheral nerves are most frequently caused by surgery, immobilization, injections, radiation, or drugs. Early recognition and diagnosis is important not to delay appropriate therapeutic measures and to improve the outcome. Treatment can be causative or symptomatic, conservative, or surgical. Rehabilitative measures play a key role in the conservative treatment, but the point at which an INL requires surgical intervention should not be missed or delayed. This is why INLs require close multiprofessional monitoring and continuous re-evaluation of the therapeutic effect. With increasing number of surgical interventions and increasing number of drugs applied, it is quite likely that the prevalence of INLs will further increase. To provide an optimal management, more studies about the frequency of the various INLs and studies evaluating therapies need to be conducted. Management of INLs can be particularly improved if those confronted with INLs get state-of-the-art education and advanced training about INLs. Management and outcome of INLs can be further improved if the multiprofessional interplay is optimized and adapted to the needs of the patient, the healthcare system, and those responsible for sustaining medical infrastructure.

Diagnostic value of markers of muscle degeneration in sporadic inclusion body myositis

Sporadic inclusion body myositis (s-IBM) is characterized histologically by the association of concomitant inflammatory and degenerative processes. We evaluated the sensitivity and specificity of different markers of the degenerative process in order to refine the histological diagnosis. We performed an immunohistochemical study with antibodies directed against ubiquitin, amyloid-beta precursor protein (AbetaPP), amyloid-beta (Abeta), SMI-31, SMI-310, Tar-DNA binding protein-43 (TDP-43) and p62 on s-IBM and control muscle biopsies. Based on conventional stains 36 patients with characteristic clinical features of s-IBM were subclassified as presumed definite s-IBM (d s-IBM, n = 17) or possible s-IBM (p s-IBM, n = 19) according to the presence or absence of vacuolated muscle fibers. Immunohistochemically, TDP-43 and p62 were the most sensitive markers, accumulating in all d s-IBM and in 31% and 37%, respectively, of the p s-IBM cases and thus enabling reclassification of these cases as d s-IBM. We recommend using TDP-43 and p62 antibodies in the histological diagnosis workup of s-IBM. The specificity of these markers has to be further validated in prospective series.

Two families with autosomal dominant progressive external ophthalmoplegia

OBJECTIVES

We report here the clinical and genetic features of two new families with autosomal dominant progressive external ophthalmoplegia (adPEO).

PATIENTS AND METHODS

The examination of index patients included a detailed clinical characterisation, histological analysis of muscle biopsy specimens, and genetic testing of mitochondrial and nuclear DNA extracted from muscle and leucocytes.

RESULTS

Index patients in both families presented with PEO and developed other clinical disease manifestations, such as myopathy and cardiomyopathy (patient 1) and axonal neuropathy, diabetes mellitus, hearing loss, and myopathy (patient 2), later in the course of illness. Both patients had ragged red fibres on muscle histology. Southern blot of mtDNA from muscle of patient 2 showed multiple deletions. In this case, a novel heterozygous missense mutation F485L was identified in the nuclear encoded putative mitochondrial helicase Twinkle. The mutation co-segregated with the clinical phenotype in the family and was not detected in 150 control chromosomes. In the other index patient, sequencing of ANT1, C10orf2 (encoding for Twinkle), and POLG1 did not reveal pathogenic mutations.

CONCLUSIONS

Our cases illustrate the clinical variability of adPEO, add a novel pathogenic mutation in Twinkle (F485L) to the growing list of genetic abnormalities in adPEO, and reinforce the relevance of other yet unidentified genes in mtDNA maintenance and pathogenesis of adPEO.

Nail-patella syndrome associated with respiratory chain disorder

Nail-patella syndrome (NPS) has not been described to be associated with a respiratory chain disorder (RCD) before. In a 42-year-old man with the typical phenotype of an NPS, weakness and wasting of the shoulder girdle muscles, muscle cramps, fatigability, hyperhidrosis, chest pain and creatine kinase elevation were observed. Echocardiography revealed left ventricular hypertrabeculation. Needle electromyography was myopathic, lactate stress testing was abnormal, muscle biopsy showed typical features of an RCD and mtDNA analysis revealed the A3243G MELAS mutation. In conclusion, this case demonstrates that NPS may be randomly associated with RCD. NPS patients should undergo detailed cardiological and neurological investigations, in order not to overlook a double trouble partially mimicking NPS.

Prognostic relevance of intracytoplasmic cytokeratin pattern, hormone expression profile, and cell proliferation in pituitary adenomas of akromegalic patients

Seventy-six pituitary adenomas of akromegalic patients were investigated to find out the prognostic relevance of the intracytoplasmic distribution of cytokeratins (CK), immunohistochemically defined hormone production profile, proliferative activity and clinical presentation. CK distribution, growth fraction (MIB1 index) and hormone production profile were analyzed by means of immunohistochemistry. Apoptotic activity was investigated by the TUNEL method. Two different CK distribution patterns were seen: a dot-like pattern in 29 cases (type 1 adenomas), and a perinuclear fibrillary pattern in 47 cases (type 2 adenomas). Type 2 adenomas showed more prominent coexpression of prolactin (p < 0.0001), luteotrophic hormone (p < 0.002), follicle-stimulating hormone (p < 0.005), thyroid-stimulating hormone (p < 0.0001), and alpha-subunit (p < 0.005), as compared to type 1 adenomas. The mean MIB1 index was significantly higher in type 1 vs. type 2 tumors (4.23%, range: 1.93% - 9.83% vs. 2.07%, range: 0.67% - 4.87%, p < 0.0001). Apoptotic activity was too low in both examined groups to be used for balancing of tumor cell turnover. Clinical analysis of patients with type 1 adenomas revealed female predominance, younger age, larger tumor size, and more frequently aggressive growth with higher incidence of suprasellar extension (p < 0.0001) and cavernous sinus infiltration (p < 0.0001), as well as larger proportions of re-operations and incomplete resections (34.5% vs. 8.51%). Additionally, the interval until re-operation was shorter in type 1 adenomas (mean: 16 months, range: 9 - 21 months vs. mean: 57 months, range: 18- 158 months). We conclude that classification of adenomas of akromegalic patients based on intracytoplasmic CK distribution, combined with examination of proliferative activity, and immunohistochemically defined hormone production profile, provides important prognostic information for the management of akromegalic patients.

Serotonergic nuclei of the raphe are not affected in human ageing

Sleep disorders increase with ageing. The serotonergic system has been linked with sleep regulation. In fatal familial insomnia, a prion disease with insomnia as one major clinical feature, we recently observed a disturbance in the serotonergic system as likely substrate of typical symptoms. Using immunohistochemistry for the serotonin synthesizing enzyme, tryptophan hydroxylase, we investigated the serotonergic median raphe nuclei (dorsal raphe nucleus, superior central nucleus, and raphe obscurus nucleus) in brains of an older (n = 12; age range 62-84 years) and a younger group (n = 10; age range 5-29 years). We found no significant difference between age groups in the percentage of neurons able to synthesize serotonin. Other changes might relate to sleep disturbances in the elderly.

Autoradiography with [3H]PK11195 of spinal tract degeneration in amyotrophic lateral sclerosis

The diagnostic hallmarks of amyotrophic lateral sclerosis (ALS) are degeneration of upper and lower motor neurons and of corticospinal tracts. Here, we demonstrate the suitability of the gliosis marker [3H]PK11195 for quantitative evaluation of tract degeneration in ALS in vitro. Binding of [3H]PK11195 was increased in lateral and ventral white matter of ALS spinal cords but not in the anterior horn, in spite of a dramatic loss in muscarinic binding sites and a high level of oxidatively modified protein. Labeling of activated microglia with [11C]PK11195 may also allow tract degeneration in ALS to be visualized in vivo.

Hypertrophic chronic pachymeningitis as a localized immune process in the craniocervical region

Hypertrophic chronic pachymeningitis (HCP) is a rare disorder that causes intracranial or spinal thickening of the dura mater. This report describes a patient with progressive HCP in the craniocervical region associated with signs of rheumatic disease. A ventricular-atrial shunt had to be inserted because of increased intracranial pressure. The patient improved after suboccipital craniotomy, C1 to C6 laminectomy, and removal of the thickened dura. Additional therapy with methotrexate stopped progression, which was documented by MRI and PET.

Acquired neuromyotonia and peripheral neuropathy in a patient with Hodgkin's disease

Acquired neuromyotonia is characterized by hyperexcitability of motor nerves resulting in continuous muscle fiber activity. It occurs most often as a paraneoplastic syndrome in patients with cancers of the immune system. Antibodies against voltage-gated potassium channels (VGKCs) have been detected in some patients. Peripheral neuropathy is sometimes present. We report on a patient with Hodgkin's lymphoma in complete remission who developed paresthesias followed by neuromyotonia with bulbar involvement. Peripheral sensorimotor neuropathy was diagnosed electrophysiologically and evidence of axonal degeneration and demyelination was detected by sural nerve biopsy. The patient's complaints, including dysarthria, improved after carbamazepine treatment.

Pseudogliomatous growth pattern of anaplastic small cell carcinomas metastatic to the brain

Carcinomas metastatic to the brain usually grow very well circumscribed, with sharp delineation. Radiosurgery takes advantage of this fact by using the gamma knife for definitive treatment of small metastases. We report a systematic study of the growth pattern of cerebral metastases, focusing on tumor delineation. In 26 cases of 66 metastatic anaplastic small cell carcinomas and in one case of adenocarcinoma, we observed poorly defined borders and a highly diffuse pattern of invasion. Infiltrating carcinoma cells changed to an elongated shape adapting to preexisting tissue structures. This pseudogliomatous growth pattern of some brain metastases--apparently most likely in neuroendocrine carcinomas--is of potential importance for therapeutic strategies in the treatment of brain metastases, especially when considering treatment with radiosurgery and gamma knife.

Alteration of the serotonergic nervous system in fatal familial insomnia

Fatal familial insomnia (FFI) is a unique hereditary prion disease with characteristic disturbances of sleep. We studied the serotonergic system in 8 FFI-affected subjects by immunohistochemistry for the serotonin-synthesizing enzyme, tryptophan hydroxylase (TH). Quantification of neurons in median raphe nuclei showed no total neuronal loss in FFI but a substantial increase of TH+ neurons (approximately 62%) in FFI subjects compared with controls. Our data indicate an alteration of the serotonergic system that might represent the functional substrate of some typical symptoms of FFI.

Selective neuronal vulnerability in human prion diseases. Fatal familial insomnia differs from other types of prion diseases

Human transmissible spongiform encephalopathies (TSEs) or prion diseases are neurodegenerative disorders of infectious, inherited or sporadic origin and include Creutzfeldt-Jakob disease (CJD), Gerstmann-Sträussler-Scheinker disease (GSS), kuru and fatal familial insomnia (FFI). Clinicopathologic features of FFI differ markedly from other human TSEs. Previous studies demonstrated selective neuronal vulnerability of parvalbumin positive (PV+) GABAergic inhibitory interneurons in sporadic CJD and experimental TSEs. In this report we show uniform severe loss of PV+ neurons also in other TSEs such as GSS, kuru, new variant and familial CJD. In contrast, these neurons are mostly well preserved, or only moderately reduced, in FFI. Only PV+ neurons surrounded by isolectin-B4 positive perineuronal nets were severely affected in TSEs, suggesting a factor residing in this type of extracellular matrix around PV+ neurons as modulator for the selective neuronal vulnerability.

Coexistence of Alzheimer-type neuropathology in Creutzfeldt-Jakob disease

Creutzfeldt-Jakob disease (CJD) and Alzheimer's disease (AD) share clinical, neuropathological, and pathogenetic features. To investigate eventual mutual influences, we screened prominently affected neocortex from 110 neuropathologically proven CJD patients for Alzheimer-type pathology with anti-beta/A4, Bielschowsky and anti-tau (immuno)stains. The neuropathological classification of Alzheimer-type pathology was made according to the CERAD criteria. Results were controlled by comparison with Alzheimer-type changes in sections from the same cortical areas in 110 sex- and age-matched non-demented control patients. For comparison, the control patients were also classified according to the CERAD neuropathology criteria as if they had been demented. Alzheimer-type tissue changes as in definite and probable CERAD AD occur in 10.9% of the CJD patients and 19.1% of control patients (P=0.11). The median age of CJD and control patients with CERAD AD is 72 and 68 years, respectively, which differs significantly from the median ages of 64 and 63 years, respectively, in the non-AD/CJD and non-AD control patients. Since CERAD criteria include "presence of other neuropathological lesions likely to cause dementia", an AD diagnosis in CJD patients (all of whom are demented) is solely based on densities of neuritic plaques. Similar Alzheimer-type changes in even higher frequency, however, are also present in elderly non-demented controls. Thus, the coexistence of Alzheimer-type pathology in CJD most likely represents an age-related change. Deposits of prion protein (PrP) frequently accumulate at the periphery of beta/A4 plaques. The presence of beta/A4 amyloid in the brain may influence PrP morphogenesis.

Proliferation and DNA fragmentation in meningioma subtypes

Atypical meningioma has been introduced as tumour subtype of intermediate biological behaviour between classical and malignant meningiomas. To substantiate this three-step scale of malignancy, we assessed the proliferative activity reflected by Ki-67 (MIB1) labelling index (LI) in a series of 89 meningiomas, including 15 classical, 29 atypical, 35 anaplastic tumours, and 10 haemangiopericytomas and papillary meningiomas. The possible correlation of proliferation with the frequency of apoptosis and their relations to BCL-2 immunoexpression was investigated in seven classical, 10 atypical and 10 malignant meningiomas. Apoptosis was demonstrated by evaluation of the frequency of apoptotic figures, by the enzymatic technique of in situ tailing (IST) which stains apoptotic DNA fragments, and by DNA preparation and gel electrophoresis demonstrating DNA laddering in frozen tissues of five meningiomas. MIB1 LI revealed a highly significant increase from classical through atypical to anaplastic meningiomas (P < 0.0001); haemangiopericytomas and papillary meningiomas were well within the range of atypical meningiomas. IST indices rose with increasing malignancy and correlated with MIB1 LI (P < 0.0001): they showed a weak inverse correlation with BCL-2 immunoexpression (P = 0.05). BCL-2 expression tended to decrease with malignancy grade and was unrelated to MIB1 LI or frequency of apoptosis. Our data show that (i) apoptosis is a feature of meningiomas, significantly correlated with the malignancy scale. (ii) DNA fragmentation shows significant correlation with proliferation and inversely with BCL-2 expression; (iii) proliferation indices and frequencies of apoptosis/DNA fragmentation within meningioma subgroups corroborate the intermediate biological position of the atypical meningioma between classical and malignant meningiomas.

Ganglionitis in paraneoplastic subacute sensory neuronopathy: a morphologic study

A 69-year-old woman presented with subacute sensory neuropathy and autonomic dysfunction of 9 months' duration, associated with high serum titers of anti-Hu antibodies. A small cell carcinoma of the lung was diagnosed by biopsy. She died after cardiorespiratory arrest. At autopsy, spinal and autonomic ganglia showed subacute inflammation with diffuse endoneurial T-cell, B-cell, and plasma cell infiltration. The cytoplasm and nuclei of some ganglion neurons displayed IgG immunocytochemical positivity. CD8+ T cells were tightly attached to, and indented the cell surface of, IgG-positive and IgG-negative neurons. This observation suggests that both cytotoxic T-cell-mediated attack against neurons and humoral mechanisms play a role in paraneoplastic subacute sensory neuronopathy.

Non-HTLV-I associated pleomorphic T-cell lymphoma of the brain mimicking post-vaccinal acute inflammatory demyelination

Two weeks after vaccination against tick-borne encephalitis (TBE), a 57-year-old female suddenly developed mental confusion and hemiparesis of the left side. Cranial MRI demonstrated extensive bilateral lesions in the fronto-parietal white matter of both hemispheres, suggesting an acute inflammatory demyelinating disease following vaccination. Despite administration of high-dose corticosteroids, the patient died 3 weeks after onset of neurological symptoms. Autopsy revealed diffuse infiltrates of a primary cerebral pleomorphic T-cell lymphoma of medium and large cell type. PCR on brain tissue for HTLV-I and serology for anti-HTLV-I antibodies in CSF and serum were negative; immunocytochemistry on brain tissue did not detect EBV-related antigen. This is the first recorded observation of a diffusely infiltrating primary central nervous system T-cell lymphoma, clinically and radiologically mimicking a fatal acute inflammatory demyelinating complication after vaccination.

Suprasellar meningioma with expression of glial fibrillary acidic protein: a peculiar variant

A 24-year-old female presented with a 3-year history of a suprasellar and intraventricular solid midline process measuring about 3 x 4 cm. At surgery, this tumour was sharply delineated and of stone-like firmness and was removed completely. Histology suggested meningioma, featuring nests and cords of epithelium-like cells with prominent cytoplasm amidst abundant fibrous stroma with prominent lymphoplasmocellular infiltration. Immunocytochemically, the tumour cells expressed vimentin, S-100 protein, epithelial membrane antigen, cytokeratins, and most surprisingly, glial fibrillary acidic protein (GFAP). Ultrastructural investigation revealed abundant intermediate filaments and occasionally dense secretory granules in tumour cells with short, finger-like cytoplasmic processes joined by very rare small, but well-developed desmosomes. This tumour most likely represents a peculiar variant of meningioma with prominent production of GFAP, as previously described [Budka H (1986) Acta Neuropathol (Berl) 72: 43-54].