Late onset spinal muscle atrophy--a sex linked variant of Kugelberg-Welander

Pilot Study on Quantitative Cervical Cord and Muscular MRI in Spinal Muscular Atrophy: Promising Biomarkers of Disease Evolution and Treatment?

Introduction: Nusinersen is a recent promising therapy approved for the treatment of spinal muscular atrophy (SMA), a rare disease characterized by the degeneration of alpha motor neurons (αMN) in the spinal cord (SC) leading to progressive muscle atrophy and dysfunction. Muscle and cervical SC quantitative magnetic resonance imaging (qMRI) has never been used to monitor drug treatment in SMA. The aim of this pilot study is to investigate whether qMRI can provide useful biomarkers for monitoring treatment efficacy in SMA. Methods: Three adult SMA 3a patients under treatment with nusinersen underwent longitudinal clinical and qMRI examinations every 4 months from baseline to 21-month follow-up. The qMRI protocol aimed to quantify thigh muscle fat fraction (FF) and water-T2 (w-T2) and to characterize SC volumes and microstructure. Eleven healthy controls underwent the same SC protocol (single time point). We evaluated clinical and imaging outcomes of SMA patients longitudinally and compared SC data between groups transversally. Results: Patient motor function was stable, with only Patient 2 showing moderate improvements. Average muscle FF was already high at baseline (50%) and progressed over time (57%). w-T2 was also slightly higher than previously published data at baseline and slightly decreased over time. Cross-sectional area of the whole SC, gray matter (GM), and ventral horns (VHs) of Patients 1 and 3 were reduced compared to controls and remained stable over time, while GM and VHs areas of Patient 2 slightly increased. We found altered diffusion and magnetization transfer parameters in SC structures of SMA patients compared to controls, thus suggesting changes in tissue microstructure and myelin content. Conclusion: In this pilot study, we found a progression of FF in thigh muscles of SMA 3a patients during nusinersen therapy and a concurrent slight reduction of w-T2 over time. The SC qMRI analysis confirmed previous imaging and histopathological studies suggesting degeneration of αMN of the VHs, resulting in GM atrophy and demyelination. Our longitudinal data suggest that qMRI could represent a feasible technique for capturing microstructural changes induced by SMA in vivo and a candidate methodology for monitoring the effects of treatment, once replicated on a larger cohort.

Spinal muscular atrophy type III complicated by spinal superficial siderosis: a case report with molecular and neuropathological findings

Spinal muscular atrophy (SMA) is largely linked to deletion or mutation of the Survival motor neuron 1 (SMN1) gene located on chromosome 5q13. Type III (Kugelberg–Welander disease) is the mildest childhood form and patients may become ambulatory and have a normal life expectancy. We report the clinical history and morphological findings of a 55-year-old woman who began to experience motor problems at the age of two. She was never fully ambulatory, and her severe scoliosis required the insertion of surgical rod at age 19. Unexpectedly, around 35 years of age, she began to experience sensory symptoms best characterized as a myelo-radiculo-neuropathy with pain as the dominant symptom. Investigations never clarified the etiology of these symptoms. Molecular confirmation of SMA type III was done post-mortem. Neuropathological examination showed classic changes of lower motor neuron neurodegeneration, in line with those reported in the single molecularly confirmed case published so far, and with findings in rare cases reported prior to the discovery of the gene defect. A key autopsy finding was the presence of a severe superficial siderosis of the lower half of the spinal cord. In recent years, the concept of duropathy was put forward, associating superficial siderosis of the spinal cord with various spinal abnormalities, some of which were present in our patient. The presence of significant hemosiderin deposits in the spinal cord and sensory nerve roots with associated tissue and axonal damage provide a plausible explanation for the unexpected sensory symptomatology in this mild lower motor neurodegeneration.

[An early history of Japanese amyotrophic lateral sclerosis (ALS)-related diseases and the current development]

The present review focuses an early history of Japanese amyotrophic lateral sclerosis (ALS)-related diseases and the current development. In relation to foreign previous reports, five topics are introduced and discussed on ALS with dementia, ALS/Parkinsonism dementia complex (ALS/PDC), familial ALS (FALS), spinal bulbar muscular atrophy (SBMA), and multisystem involvement especially in cerebellar system of ALS including ALS/SCA (spinocerebellar ataxia) crossroad mutation Asidan. This review found the great contribution of Japanese reports on the above five topics, and confirmed the great development of ALS-related diseases over the past 120 years.

Clinical aspects of CAG repeat diseases

Seven neurodegenerative disorders are known to be caused by unstable expansions of the trinucleotide CAG within human genes, and more will be discovered in the coming years. These disorders share some clinical similarities, as well as some differences, which are summarized here. These diseases have unusual clinical genetic properties related to the dynamic nature of CAG repeat expansions, including instability of the repeat expansion in meiosis, particularly male meiosis; a strong correlation between onset age and size of the repeat expansion; anticipation (earlier disease onset in succeeding generations); new mutations arising from unstable, mutable alleles with a high-normal CAG repeat number; and reduced penetrance for alleles in the low-affected range. Much more remains to be learned about the molecular biology and clinical pathophysiology of this new class of genetic diseases.

Regional cerebral blood flow and neuropsychological performance in a Danish family with X-linked bulbo-spinal neuronopathy

Regional Cerebral Blood Flow (rCBF) measurements and neuropsychological evaluation were performed in 6 patients from a Danish family affected with X-linked Bulbo-Spinal Neuronopathy (XBSN). This inherited form of motor neuron disease (MND) has been shown to affect various functions within the nervous and the endocrine systems. We investigated the possibility that focal or diffuse cortical deficits, already demonstrated in MND, were present in XBSN. The global CBF values of the patients, when compared to age- and sex-matched healthy controls, were found reduced, but no focal rCBF alterations, nor increased regional side-to-side asymmetry were observed. The neuropsychological evaluation showed no cognitive impairments. We conclude that cortical perfusion and cognitive functions are not significantly altered in XBSN.

Doença de Kennedy: Relato de dois casos

Relatamos, pela primeira vez em nosso meio, dois pacientes com atrofia muscular bulbo espinhal de início tardio (doença de Kennedy), caracterizada por fraqueza, atrofia muscular, tremores e manifestações endocrinológicas, com sinais eletromiográficos de desnervação. Esta entidade diferencia-se das demais doenças do neurônio motor pela sua peculiar herança ligada ao sexo, anormalidades endocrinas (ginecomastia, atrofia testicular e oligoespermia), tendo prognóstico relativamente favorável. Discutimos a caracterização clínica dos doentes apresentados, o aspecto fisiopatológico e a evolução.

Sensory neuron degeneration in familial Kugelberg-Welander disease

A 53 year old man developed symptoms of motor neuron disease in childhood. There was a family history of a similar disorder and it was felt to represent a form of Kugelberg-Welander disease. In addition to the motor deficits, sensory abnormalities in his legs were documented during life. Autopsy revealed anterior horn cell loss throughout the length of the spinal cord, with preservation of the phrenic nucleus. The lumbar dorsal root ganglia showed active degeneration of sensory neurons, with nuclear changes exceeding cytoplasmic ones. The fasciculus gracilis showed Wallerian degeneration. The findings provide direct evidence that sensory neurons can degenerate in some forms of motor neuron disease, and that the "demyelination" or "degeneration" of posterior columns sometimes seen in the various forms of motor neuron disease may actually be secondary to cell body disease in the dorsal root ganglia.

Familial bulbo-spinal muscular atrophy associated with testicular atrophy and sensory neuropathy (Kennedy-Alter-Sung syndrome). Autopsy case report of two brothers

Autopsy cases of two brothers with bulbo-spinal muscular atrophy associated with gynecomastia, testicular atrophy and sensory neuropathy are reported. The disease started with finger tremor, proximal muscle weakness and facial muscle twitching at the second and fourth decades, accompanied by bulbar signs and glove-stocking type sensory disturbance. Systemic neurogenic patterns and diminished sensory nerve action potential amplitudes were recorded by electrophysiological studies. A marked loss of myelinated fibers was noticed upon sural nerve biopsy. Gonadal hormone values were normal, except for elevated urinary estrogen. Postmortem examinations revealed a remarkable degeneration of the facial and hypoglossal nuclei, and the spinal cord motoneurons. The skeletal muscles and the tongue showed neurogenic muscular atrophy with fatty replacement. Testicular atrophy was prominent showing hyalinized seminiferous tubuli with nodular and diffuse Leydig cell hyperplasia, containing estrogen immunoreactive substance. These clinical and histological features seemed to be highly compatible with those of Kennedy-Alter-Sung type bulbo-spinal muscular atrophy. The involvement of sensory peripheral nerves, however, was a distinct feature of this family.

Clinical-anatomic study of a family with bulbo-spinal muscular atrophy in adults

Four cases are presented, with bulbo-spinal muscular atrophy characterised by adult onset and rapid evolution. They belong to a family in which the type of inheritance is probably dominant. Two cases were studied histologically. The most striking feature was the disappearance of neurons in the lower motor nuclei of medulla and of the spinal anterior horns. An electron microscopic study was carried out in one case. Accumulation of neurofilaments was a general characteristic, in addition to the picture of different sized spheroids. The clinical-pathological relationship is discussed.

X-linked adult form of spinal muscular atrophy

Neurological and endocrinological studies were carried out in 8 of 12 male patients with X-linked spinal muscular atrophy. In six investigated cases, gynaecomastia was discovered. First muscle symptoms started between 21 and 44 years of age, at which time the patients observed disturbances in their sexual life. In three cases decreased fertility and in two cases sterility was reported. Diagnostic testicular biopsy showed pronounced involutional changes of the Leydig cells. The plasma testosterone level was decreased, while the levels of luteinizing hormone and prolactine were normal, and the follicle stimulating hormone was at a high normal level. The dexamethasone/human chorionic gonadotrophin test revealed a pronounced decrease in the functional reserve of the Leydig cells. It is suggested that all these anomalies are connected with an increased ratio of oestrogen to androgen level.

Spinal and cranial motor nerve roots in amyotrophic lateral sclerosis and X-linked recessive bulbospinal muscular atrophy: morphometric and teased-fiber study

Amyotrophic lateral sclerosis (ALS) and adult onset X-linked recessive bulbospinal muscular atrophy (SPMA), constituting the category of adult onset form of motor neuron disease, were analyzed on motor nerve roots. The results of morphometric analysis on ventral spinal roots (VSR) of all spinal segments from ALS and SPMA revealed the following three findings: (1) the large-myelinated alpha-motoneuron fibers were markedly decreased in number throughout all segments; (2) thin-myelinated autonomic preganglionic fibers were almost completely preserved; (3) small-intermediate-myelinated fibers which are considered to correspond to gamma-motoneuron fibers were generally well preserved in ALS, but decreased by one-half to one-third in SPMA. However, all the components of the nerve roots of the oculomotor, trochlear, and abducent nerves were completely preserved in both ALS and SPMA. Moreover, the teased-fiber study showed that the regenerating-sprouting process rarely occurred in the VSR of ALS and SPMA. The present study suggested that the site of the primary lesion seems to be in the alpha-motoneuron fibers in motor neuron diseases, such as ALS or SPMA. However, the marked discrepancy in the pathologic change in the alpha-motoneuron fibers in the VSR and the nerve roots innervating the external ocular muscles was noteworthy.