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PubMed1997

[Delayed exacerbation of cervical myelopathy in a case of juvenile muscular atrophy of unilateral distal upper extremity].

We reported a case in which cervical myelopathy exacerbated 20 years after the stabilization of juvenile muscular atrophy of unilateral distal upper extremity. The patient presented progressive weakness in the right proximal upper extremity and spastic paraparesis in addition to the long-lasting muscular atrophy of right distal upper extremity. Plain x-ray showed severe cervical spondylosis with kyphosis of the cervical spine. Dynamic study on MRI disclosed cervical spinal cord atrophy and compression enhanced in both flexion and extension position of the neck. Malalignment (kyphosis) and severe spondylotic change of the cervical spine seemed to affect the spinal cord with little functional reservoir, manifesting the delayed exacerbation of myelopathy. We conclude that malalignment and subsequent spondylotic change of the cervical spine would be significant factors to determine the long term prognosis of patients with juvenile muscular atrophy of unilateral distal upper extremity.

Arm↗

PubMed1997

Magnetic resonance imaging correlates of memory impairment in the healthy elderly: association with medial temporal lobe atrophy but not white matter lesions.

OBJECTIVE: To investigate the neuroradiological correlates of age-related cognitive decline in the elderly. DESIGN: A sample of healthy control subjects underwent magnetic resonance imaging (MRI) scanning and cognitive testing. SETTING: Melbourne, Australia. PARTICIPANTS: 40 volunteers over the age of 55 who were spouses of subjects seen in a hospital memory clinic, subjects from a register of normal volunteer subjects (not staff) kept for research purposes or residents of a retirement hostel. MEASURES: Hippocampal and amygdala (HA) atrophy, periventricular lesions (PVL) and deep white matter lesions (DWML) were rated by two radiologists blind to cognitive test score results. Cognitive assessment was by the Cambridge Cognitive Examination (CAMCOG). RESULTS: After controlling for age and education, lower scores on the memory subscale of the CAMCOG were associated with the presence of HA atrophy, but not with DWML or PVL. CONCLUSIONS: HA atrophy on MRI is associated with impaired memory performance in the healthy elderly, while PVL and DWML are not. Further study should determine whether HA atrophy is a risk factor for developing dementia.

Aged↗

PubMed1997

BDNF and NT-4/5 prevent atrophy of rat rubrospinal neurons after cervical axotomy, stimulate GAP-43 and Talpha1-tubulin mRNA expression, and promote axonal regeneration.

Rubrospinal neurons (RSNs) undergo a marked atrophy in the second week after cervical axotomy. This delayed atrophy is accompanied by a decline in the expression of regeneration-associated genes such as GAP-43 and Talpha1-tubulin, which are initially elevated after injury. These responses may reflect a deficiency in the trophic support of axotomized RSNs. To test this hypothesis, we first analyzed the expression of mRNAs encoding the trk family of neurotrophin receptors. In situ hybridization revealed expression of full-length trkB receptors in virtually all RSNs, which declined 7 d after axotomy. Full-length trkC mRNA was expressed at low levels. Using RT-PCR, we found that mRNAs encoding trkC isoforms with kinase domain inserts were present at levels comparable to that for the unmodified receptor. TrkA mRNA expression was not detected in RSNs, and the expression of p75 was restricted to a small subpopulation of axotomized cells. In agreement with the pattern of trk receptor expression, infusion of recombinant human BDNF or NT-4/5 into the vicinity of the axotomized RSNs, between days 7 and 14 after axotomy, fully prevented their atrophy. This effect was still evident 2 weeks after the termination of BDNF treatment. Moreover, BDNF or NT-4/5 treatment stimulated the expression of GAP-43 and Talpha1-tubulin mRNA and maintained the level of trkB expression. Vehicle, NGF, or NT-3 treatment had no significant effect on cell size or GAP-43 and Talpha1-tubulin expression. In a separate experiment, infusion of BDNF also was found to increase the number of axotomized RSNs that regenerated into a peripheral nerve graft. Thus, in BDNF-treated animals, the prevention of neuronal atrophy and the stimulation GAP-43 and Talpha1-tubulin expression is correlated with an increased regenerative capacity of axotomized RSNs.

Animals↗

PubMed1997

Cerebellar atrophy with basilar artery occlusion.

Small and large vessel occlusive disease leading to chronic cerebral ischemia and brain atrophy is a concept originating in the last century. The modern notion of acute brain infarct, however, appears to have eclipsed the idea of chronic hypoperfusion as an important factor in ischemic cerebral damage. We present a patient history featuring recurrent episodes of acute posterior circulation infratentorial ischemia in addition to a progressive cerebellar syndrome over a course of several years. Laboratory work-up including cerebral angiography, repeated CT and MR scanning revealed basilar artery occlusion, a pontine infarct and a subsequently developing cerebellar atrophy without signs of cerebellar infarction. Findings indicating causes of cerebellar atrophy other than ischemia could not be elicited. We offer the hypothesis that basilar artery occlusion, inducing subsequent chronic ischemia, is the most likely cause of the cerebellar atrophy observed in our case.

Adult↗

PubMed1997

[Diagnosis of thymoma and thymic atrophy in patients with myasthenia gravis].

We have compared clinical, immunological and radiological data in 20 patients with myasthenia gravis and thymoma and in 21 patients with myasthenia gravis and thymic atrophy. The median age at onset was 54 years in the thymoma group and 63 years in the thymic atrophy group (p = 0.04). The severity of the disease was similar in the two groups, and there was no significant difference in the concentration of acetylcholine receptor antibodies. CA antibodies were demonstrated in 17/20 thymoma patients and in 6/21 with thymic atrophy, while 19/20 thymoma patients had antibodies to titin, compared with 9/21 among those with thymic atrophy. The diagnosis and treatment of patients with myasthenia gravis is based upon an evaluation of clinical, immunological and radiological data.

Adult↗

PubMed1998

Parapapillary chorioretinal atrophy in chronic high-pressure experimental glaucoma in rhesus monkeys.

PURPOSE: To evaluate in rhesus monkeys parapapillary chorioretinal atrophy in chronic high-pressure glaucoma and the effects of age, atherosclerosis, and chronic arterial hypertension in a prospective, planned study. METHODS: Seventy-six eyes from 38 monkeys were studied. First, experimental atherosclerosis and chronic arterial hypertension were produced in 24 animals. Then experimental high-pressure glaucoma was produced by laser photocoagulation of the anterior chamber angle in 38 eyes from the 38 animals. Intraocular pressure measurements and fundus photography were serially performed. The photographs were morphometrically analyzed. RESULTS: In the glaucomatous eyes, area and frequency of beta zone of parapapillary atrophy were significantly (P < 0.0001) larger at the end of the study than at baseline. Area of beta zone was significantly (P < 0.0001) and negatively correlated with neuroretinal rim area. In an intraindividual intereye comparison, beta zone was significantly (P < 0.0001) larger in the glaucomatous than in the contralateral nonglaucomatous eyes. Increase of beta zone and loss of neuroretinal rim were independent of presence and size of beta zone at start of the study. Beta zone was significantly (P = 0.036) greater in older than in younger monkeys; however, atherosclerosis-arterial hypertension had no significant influence on frequency and size of beta zone. Area and frequency of alpha zone showed no significant change between baseline values and those at the end of study. CONCLUSIONS: In experimental chronic high-pressure glaucoma in monkeys, beta zone of parapapillary atrophy was positively correlated with glaucomatous optic nerve damage. This confirms previous biomorphometric and histomorphometric studies on patients with glaucoma. In chronic experimental high-pressure glaucoma, neuroretinal rim loss and an increase of beta zone may be independent of preexisting parapapillary atrophy. Increase of beta zone may be independent of concomitant atherosclerosis-arterial hypertension.

Aging↗

PubMedDate not supplied

Ewing's sarcoma in a patient with congenital optic atrophy.

PURPOSE: The authors report Ewing's sarcoma in a patient with congenital optic atrophy. Congenital optic atrophy is an autosomal dominant disorder with variable expression. It manifests itself within the first decade of life and is accompanied by changes in visual acuity. This condition has not been known to cause a predisposition toward malignancy. PATIENT AND METHODS: In this article, a 16-year-old girl with dominant optic atrophy and Ewing's sarcoma is described. RESULTS: After tumor resection, the patient was successfully treated for Ewing's sarcoma with chemotherapy and radiation therapy. Today she has no evidence of malignancy. However, she continues to have deterioration of her visual acuity. CONCLUSION: This report of cancer in a child with dominant optic atrophy suggests the possible need for a higher degree of suspicion of malignancy in these patients.

Adolescent↗

PubMed1998

[A case of juvenile muscular atrophy of the upper limb with intraspinal cavity formation].

The patient was a 23-year-old man. He had no history of trauma in the head and neck. When he was 20 years old (in 1992), he noticed muscle atrophy and weakness in the right hand. In a hospital, he had cervical MRI study and other examinations. The diagnosis was juvenile muscular atrophy of the upper limb (Hirayama's disease). After that the symptoms became worse in the bilateral forearms and hands. The neurological examination showed severe atrophy in bilateral C7 to Th1 innervated muscles, right pyramidal sign, mild superficial and deep sensory disturbance in the dermatome of C7-Th1, and right Horner's sign. Cervical MRI and myelography revealed the atrophy of cervical cord and intraspinal cavity formations from C5 to Th1. We concluded that chronic and intermittent compression to cervical cord with flexion position made the cavities during the clinical course because these cavities were not found in the MRI taken in 1992.

Adult↗

PubMed2002

Corneal endothelial degeneration in dentatorubral-pallidoluysian atrophy.

BACKGROUND: Dentatorubral-pallidoluysian atrophy (DRPLA) is an autosomal dominant spinocerebellar degeneration that exhibits a variety of neurologic manifestations. However, only a few reports have studied disturbances outside the central nervous system. We described 2 unrelated patients with DRPLA accompanied by corneal endothelial degeneration. PATIENTS AND METHODS: A 52-year-old man presented with cerebellar ataxia and dementia. Magnetic resonance imaging of the brain showed cerebellar atrophy. Dentatorubral-pallidoluysian atrophy was diagnosed because of the detection of expansion of CAG repeats at the DRPLA locus. On admission, his visual acuity was severely impaired. Specular microscopy showed decreased endothelial cell density (500 cells/mm(2)) compared with that of healthy subjects. The second patient was a 69-year-old man with cerebellar ataxia. Magnetic resonance imaging of the brain showed cerebellar and brainstem atrophy. The diagnosis of DRPLA was based on expanded CAG repeats of the DRPLA gene. Specular microscopy showed significant decrease of endothelial cell density (1506 cells/mm(2)). Reverse transcriptase-polymerase chain reaction analysis showed DRPLA gene expression in corneal endothelial cells. CONCLUSIONS: Mutant DRPLA protein may be directly associated with corneal endothelial degeneration. Corneal endothelial cell loss is an important sign of DRPLA, and the corneas of patients with DRPLA should be examined.

Aged↗

PubMed2006

Frontotemporal lobar degeneration without lobar atrophy.

BACKGROUND: Frontotemporal lobar degeneration with ubiquitin-only-immunoreactive neuronal inclusions (FTLD-U) is the most common form of frontotemporal dementia. Neuronal loss and gliosis in cornu ammonis 1 and the subiculum of the hippocampus are features of hippocampal sclerosis (HpScl), which occurs in many cases of FTLD-U. OBJECTIVE: To determine if there were any clinical or magnetic resonance imaging correlates of HpScl in FTLD-U. DESIGN: We reviewed demographics and clinical features of 24 cases of FTLD-U and subjectively assessed the severity of neuronal loss and frequency of ubiquitin-positive neuronal lesions in the frontal and temporal cortices and the dentate gyrus of the hippocampus. SETTING: Mayo Clinic, Rochester, Minn. Patients Twenty-six cases were identified from the medical records linkage system query that met clinical criteria and had autopsy material available for additional studies. Two cases were excluded from further analysis after pathologic studies revealed coexisting Alzheimer disease, leaving 24 cases included in the study. Cases were subdivided based on the presence or absence of HpScl. MAIN OUTCOME MEASURES: Patterns of gray matter atrophy were assessed in cases of FTLD-U with and without HpScl using voxel-based morphometry. RESULTS: Six of the 24 cases of FTLD-U did not have HpScl. No differences were found in demographic or clinical features, including disease duration, between cases with and without HpScl; however, voxel-based morphometry analysis revealed minimal cortical atrophy in cases without HpScl, which was significantly different from the pattern of moderate to severe frontal and temporal lobe atrophy in FTLD-U with HpScl. This finding was in keeping with histopathologic observations. CONCLUSIONS: Despite similar clinical features, cases of FTLD-U with HpScl differ from those without HpScl with respect to pathologic findings and structural imaging. Specifically, FTLD-U without HpScl showed on average minimal or no cortical atrophy, even at end-stage disease. Consequently, FTLD-U without HpScl does not conform to the proposed FTLD staging scheme, is underrecognized, and may have different genetic and environmental underpinnings.

Aged↗

PubMed2000

Glucocorticoids and hippocampal atrophy in neuropsychiatric disorders.

An extensive literature stretching back decades has shown that prolonged stress or prolonged exposure to glucocorticoids-the adrenal steroids secreted during stress-can have adverse effects on the rodent hippocampus. More recent findings suggest a similar phenomenon in the human hippocampus associated with many neuropsychiatric disorders. This review examines the evidence for hippocampal atrophy in (1) Cushing syndrome, which is characterized by a pathologic oversecretion of glucocorticoids; (2) episodes of repeated and severe major depression, which is often associated with hypersecretion of glucocorticoids; and (3) posttraumatic stress disorder. Key questions that will be examined include whether the hippocampal atrophy arises from the neuropsychiatric disorder, or precedes and predisposes toward it; whether glucocorticoids really are plausible candidates for contributing to the atrophy; and what cellular mechanisms underlie the overall decreases in hippocampal volume. Explicit memory deficits have been demonstrated in Cushing syndrome, depression, and posttraumatic stress disorder; an extensive literature suggests that hippocampal atrophy of the magnitude found in these disorders can give rise to such cognitive deficits.

Adult↗

PubMed1990

Differing patterns of striatal 18F-dopa uptake in Parkinson's disease, multiple system atrophy, and progressive supranuclear palsy.

Using positron emission tomography (PET), we studied regional striatal 18F-dopa uptake in 16 patients with L-dopa-responsive Parkinson's disease (PD), 18 patients with multiple system atrophy, and 10 patients with progressive supranuclear palsy. Results were compared with those of 30 age-matched normal volunteers. The patients with PD showed significantly reduced mean uptake of 18F-dopa in the caudate and putamen compared to controls, but while function in the posterior part of the putamen was severely impaired (45% of normal), function in the anterior part of the putamen and in the caudate was relatively spared (62% and 84% of normal). Mean 18F-dopa uptake in the posterior putamen was depressed to similar levels in all patients. Unlike patients with PD, the patients with progressive supranuclear palsy showed equally severe impairment of mean 18F-dopa uptake in the anterior and posterior putamen. Caudate 18F-dopa uptake was also significantly lower in patients with progressive supranuclear palsy than in patients with PD, being depressed to the same level as that in the putamen. Mean 18F-dopa uptake values in the anterior putamen and caudate in patients with multiple system atrophy lay between PD and progressive supranuclear palsy levels. Locomotor disability of individual patients with PD or multiple system atrophy correlated with decline in striatal 18F-dopa uptake, but this was not the case for the patients with progressive supranuclear palsy. We conclude that patients with PD have selective nigral pathological features with relative preservation of the dopaminergic function in the anterior putamen and caudate, whereas there is progressively more extensive nigral involvement in multiple system atrophy and progressive supranuclear palsy.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1976

Effect of peripheral anatomy on the fine structure and histochemistry of the Rolando substance: degenerative atrophy of central processes of pseudounipolar cells.

Disappearance of fluorid-resistant acid phosphatase activity from the ipsilateral Rolando substance after transection of the peripheral nerve, is shown to be due to the cessation of enzyme supply from dorsal root ganglion cells to their central terminals. This is accompanied by (or ensues in consequence of) a fine structural derangement of these terminals ("degenerative atrophy"). Fine structural alterations of axon terminals undergoing degenerative atrophy, though similar to some extent to those seen during early phases of a Wallerian degeneration, are markedly different. Also myelinated nerve fibers, both in the dorsal horn and in dorsal columns, are affected by degenerative atrophy. This important, new trophical feature of sensory ganglion cells suggests a delicate metabolic balance between peripheral and central axonal branches of bipolar (pseudounipolar) cells. Degenerative atrophy raises serious implications in evaluating hodological experiments based upon Wallerian degeneration and offers new perspectives for theoretical and clinical neurology.

Acid Phosphatase↗

PubMed1998

Usefulness of ultrasound in Sudeck's atrophy of the foot.

Quantitative ultrasound (QUS) of bone has been proposed as an inexpensive and radiation-free device method of assessing skeletal status. QUS has been widely used in the assessment of osteoporosis. Until now only few data are available on the usefulness of QUS in different disorders, such as Sudeck's atrophy. To evaluate the ability of QUS in the diagnosis and monitoring of regional osteoporosis, we investigated 19 patients (12 women and 7 men, age range 30-65 years) with osteoporosis of the foot (Sudeck's atrophy), as evidenced by X-ray study and Technetium-99 bone scan. In all patients we measured speed of sound (SOS), broadband ultrasound attenuation (BUA), and stiffness of the calcaneus using Lunar Achilles Ultrasound, both in the affected and unaffected foot. Bone mineral density at the lumbar spine, by DXA (Hologic QDR 1000), was also performed. QUS was repeated after 3 and 6 months of treatment with salmon calcitonin (100 IU I.M. every second day). At baseline, SOS, BUA, and stiffness, expressed as T-score, were -1.9, -2.4, and -2.4 in unaffected feet and -2.9, -5.1, and -4.3, respectively, in affected feet. The difference between the unaffected and affected foot was significant for SOS, BUA, and stiffness (P < 0.001). No significant difference was found in QUS parameters in the unaffected foot during the study period. After 3 and 6 months of treatment, SOS increased in the affected foot by 0.2% and 0.3%, BUA increased by 6. 2% and 8.2%, and stiffness by 7.5% and 11.1%, respectively. In conclusion, BUA and stiffness seem to be influenced more than SOS by Sudeck's atrophy; QUS, namely, BUA and stiffness, significantly increase with calcitonin treatment. In conclusion, QUS is a sensitive tool in the diagnosis of Sudeck's atrophy of the foot and is adequate for measuring improvement in bone status following treatment.

Adult↗

PubMed2005

Corticotropin releasing factor 2 receptor agonists reduce the denervation-induced loss of rat skeletal muscle mass and force and increase non-atrophying skeletal muscle mass and force.

Of the two corticotropin releasing factor receptors known, corticotrophin releasing factor 2 receptor (CRF2R) is expressed in skeletal muscle. The function of this receptor in skeletal muscle is at present unknown. In order to better understand the role of the CRF2R in skeletal muscle, we treated rats with CRF2R agonists and evaluated the effect of these agents on normal and denervated muscle mass. Rats treated with the non-selective CRFR agonist, sauvagine, did not demonstrate any significant and consistent change in non-denervated and denervated fast twitch [tibialis anterior (TA) or extensor digitorum longus (EDL)] or slow/mixed twitch [medial gastrocnemius (MG) or soleus] fiber muscle mass. In adrenalectomized rats, sauvagine treatment resulted in no significant and consistent change in non-denervated fast or slow/mixed twitch fiber muscles but did cause a significant and consistent increase in denervated fast twitch (TA and EDL) but not slow/mixed twitch muscle mass. Interestingly adrenalectomy had no effect on the degree of muscle atrophy. Rats treated with the CRF2R selective agonist urocortin 2 demonstrated an increase in non-denervated and denervated fast and slow/mix twitch fiber muscle mass. The urocortin 2 induced increase in muscle mass was accompanied by an increase in muscle fiber cross-sectional area and muscle absolute force. These studies demonstrated that activation of the CRF2R decreased the level of skeletal muscle mass, force, and myocyte cross-sectional area loss resulting from sciatic nerve damage and increased the mass, force and myocyte cross-sectional area of normal (non-atrophying) skeletal muscle. In addition, we also observed that removal of the adrenals increased the effectiveness of the non-selective CRFR agonists sauvagine, presumably via the removal of the pro-atrophy influence of adrenal produced corticosteroids. These results demonstrate that pharmacological modulation of the CRF2R may be a viable method to treat skeletal muscle atrophy.

Amphibian Proteins↗

PubMed1994

2,3,7,8-Tetrachlorodibenzo-p-dioxin-induced thymic atrophy and lymphocyte stem cell alterations by mechanisms independent of the estrogen receptor.

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) has both agonist and antagonist effects on estrogen-mediated activities and estrogen receptor (ER) levels in epithelial tissues following exposure. We previously demonstrated that TCDD alters bone marrow lymphocyte stem cells, including prothymocytes, as measured by functional assays and alterations in the lymphocyte stem cell-specific markers terminal deoxynucleotidyl transferase (TdT) and recombinase activating gene-1 (RAG-1). We have also shown that 17 beta-estradiol valerate (E2V) affects lymphocyte stem cells by reducing TdT and RAG-1 mRNA. It has been suggested that the effect of TCDD on these lymphocyte stem cells may be mediated directly or indirectly through estrogenic action and/or the ER. Studies were designed to evaluate whether endogenous estrogens or the ER mediate TCDD-elicited bone marrow alterations and thymic atrophy. Ovariectomy did not alter the sensitivity of mice to TCDD-induced thymic atrophy or to a reduction in TdT biosynthesis in bone marrow cells compared with either intact or sham-operated mice. The pure estrogen antagonist ICI 164,384 blocked E2V-induced uterine hypertrophy, thymic atrophy and reductions in lymphocyte stem cell markers. However, the antiestrogen failed to protect against TCDD-elicited thymic atrophy or bone marrow alterations in intact animals. The results are consistent with the hypothesis that the effects of TCDD on the thymus and/or bone marrow are mediated by mechanisms independent of estrogens or the ER.

Animals↗

PubMed1995

Polyubiquitin in crustacean striated muscle: increased expression and conjugation during molt-induced claw muscle atrophy.

The claw muscles of decapod crustaceans undergo a molt-induced atrophy to facilitate withdrawal of the claws at ecdysis. Polyubiquitin expression, as well as the levels of ubiquitin conjugates, a ubiquitin-conjugating enzyme involved in the ATP/ubiquitin-dependent proteolytic pathway (crustacean E2(16 kDa) homolog of Drosophila UbcD1), and proteasome, were examined to determine the role of ATP/ubiquitin-dependent proteolysis in the enhanced degradation of myofibrillar proteins during muscle atrophy. A partial-length clone (1.7 kb) of polyubiquitin was isolated from a lobster muscle cDNA library; the 5' end lacked the 5' untranslated region (UTR) and the beginning of the first ubiquitin monomer, while the 3' end contained the terminal ubiquitin monomer and 3' UTR. The deduced amino acid sequence was 100% identical with that from Manduca, Drosophila, and human. In land crab claw muscle, the polyubiquitin mRNA (2.7 kb) increased about 5-fold and ubiquitin-protein conjugates (> 200 kDa) increased about 8-fold during atrophy. In contrast, the level of a ubiquitin-conjugating enzyme (E2(16 kDa)) remained unchanged. The proteasome, which constitutes the catalytic core of the ATP/ubiquitin-dependent proteinase complex, increased about 2-fold during proecdysis, reaching its highest level immediately before ecdysis. These results suggest that the ATP/ubiquitin-dependent proteolytic pathway contributes to the changes in protein metabolism that occur during molt-induced muscle atrophy.

Amino Acid Sequence↗

PubMed1998

Cell-specific survival motor neuron gene expression during human development of the central nervous system: implications for the pathogenesis of spinal muscular atrophy.

Spinal muscular atrophy is an autosomal recessive disorder characterized by the progressive loss or degeneration of the motor neurons. To investigate the expression of survival motor neuron (SMN), the spinal muscular atrophy-determining gene, and its relationship with the pathogenesis of the disease, we analyzed by means of in situ hybridization the location of SMN mRNA in fetal, newborn, infant, and adult human central nervous system tissues. The large motor neurons of the spinal cord are the main cells that express SMN together with the neurons of the medulla oblongata, the pyramidal cells of the cortex, and the Purkinje cells of the cerebellum. Some sensory neurons from the posterior horn and dorsal root ganglia express SMN to a lesser degree. Furthermore, strong SMN expression is detected in the ependymal cells of the central canal. The expression is present in the spinal cord at 8 weeks of fetal life throughout postnatal and adult life. The sharp expression of SMN in the motor neurons of the human spinal cord, the target cells in spinal muscular atrophy, suggests that this gene is implicated in neuronal development and in the pathogenesis of the disease. The location of the SMN gene expression in other neuronal structures not clearly or directly associated with clinical manifestations or pathological findings of spinal muscular atrophy may indicate a varying sensitivity to the absence or dysfunction of the SMN gene in motor neurons.

Adult↗