Normal Muscle Biopsy: Causes & Reasons

Possible Causes for Normal Muscle Biopsy

Infantile-Onset Ascending Hereditary Spastic Paralysis

Infantile-onset ascending hereditary spastic paralysis (IAHSP) is a rare, early-onset autosomal recessive motor neuron disease associated with mutations in ALS2. We studied a 17-year-old boy who had features of IAHSP. We also reviewed the current literature on ALS2-related syndromes. Clinical and neuroimaging[…] [ncbi.nlm.nih.gov]

Mitochondrial Myopathy with Reversible Cytochrome C Oxidase Deficiency

Muscle biopsy showed normal muscle fibers, normal mitochondria and type II hypotrophy, in agreement with clinical and neurophysiological signs consistent with a suprasegmental [semanticscholar.org]

[…] morphologically normal at the second biopsy. [ncbi.nlm.nih.gov]

September 1982 Journal of Neurology volume 227, pages 201–207 (1982)Cite this article 69 Accesses 63 Citations Metrics details Summary A 4-month-old girl had hypotonia, muscle [link.springer.com]

Late-Onset Pompe Disease

Further, the muscle biopsy can be nonspecific or even normal if sampling from a mildly affected muscle.1 While a vacuolar myopathy with accumulation of glycogen is a classic [ncbi.nlm.nih.gov]

[…] tissue, can provide a definitive diagnosis.32 Although muscle biopsy often reveals a vacuolar myopathy with increased amounts of glycogen,31,33 a normal muscle biopsy does [ncbi.nlm.nih.gov]

Images provided by Dr Yalda Nilipour In some cases, muscle biopsy can be normal or show non-specific changes using routine techniques of evaluation. [ncbi.nlm.nih.gov]

Central Core Disease

Muscle biopsy disclosed almost complete predominance of type-1 fibers, and fibers with central cores. This is the first report of AS and CCD. [ncbi.nlm.nih.gov]

Gastrocnemius muscle biopsy showed central cores in over 80% of the fibers on H&E section. [ncbi.nlm.nih.gov]

Muscle biopsy revealed type 1 fiber atrophy and central core abnormalities. [ncbi.nlm.nih.gov]

Distal Myopathy Type 3

Diagnostic methods Diagnosis of MM relies on laboratory findings showing an elevated serum creatine kinase level (20 to 150 times the normal), muscle biopsy routine reveals [orpha.net]

Normal CMAP amplitudes: Small SNAPs: Normal Muscle biopsy Fiber type grouping Grouped atrophy Ultrastructure: Abnormal mitochondria; Paracrystalline inclusions Intellectual [neuromuscular.wustl.edu]

Distal latency occasionally long Sensory: Normal EMG: Distal fibrillations & Polyphasic large potentials Muscle biopsy: Varied fiber size MRI: Atrophy of distal leg muscles [neuromuscular.wustl.edu]

Tibial Muscular Dystrophy

Serum CK concentration may be normal or slightly elevated. [ncbi.nlm.nih.gov]

Muscle biopsy shows progressive dystrophic changes in the tibialis anterior muscle with rimmed vacuoles at the early stages and replacement with adipose tissue at later stages [ncbi.nlm.nih.gov]

Muscle MRI shows selective fatty degeneration of the anterior tibial muscles and other anterior compartment muscles of the lower legs. [ncbi.nlm.nih.gov]

Focal Myositis

The pseudo-tumor can be painful, but is not associated with a muscle weakness. Creatine kinase level is normal. [pubmed.ncbi.nlm.nih.gov]

Muscle MRI shows an inflammation restricted to a muscle or a muscle group. [pubmed.ncbi.nlm.nih.gov]

Muscle biopsy and pathological analysis remain necessary for the diagnosis, showing inflammatory infiltrates composed by macrophages and lymphocytes without any specific distribution [pubmed.ncbi.nlm.nih.gov]

Miyoshi Myopathy Type 1

Diagnostic methods Diagnosis of MM relies on laboratory findings showing an elevated serum creatine kinase level (20 to 150 times the normal), muscle biopsy routine reveals [orpha.net]

The first application aims at visualizing molecules which are developmentally, neurally, and/or immunologically regulated and not expressed by normal muscle. [scienceopen.com]

In this disease the frozen muscle biopsy shows unique or multiple fiber muscles vacuoles .Another distal autosomic dominant myopathy is the form described by Lang and col. [scielo.br]

Myoadenylate Deaminase Deficiency

Abstract Adenylate deaminase activity was determined in cultured muscle cells of different maturation grades and muscle biopsies from normal subjects and four patients with [ncbi.nlm.nih.gov]

Despite the absence of more than 99% of normal adenylate deaminase activity, the muscle biopsy shows no anatomic pathology, and other enzymes are at normal levels. [ncbi.nlm.nih.gov]

Adenylate deaminase activity was much lower in cultured human muscle cells than in normal muscle. The activity increased with maturation. [ncbi.nlm.nih.gov]

Myopathic Carnitine Deficiency

By biochemical assay, cytochrome c oxidase (cytochrome aa3) was 6% of normal in muscle biopsy and undectectable in autopsy muscle; spectra and content of cytochromes showed [n.neurology.org]

Serum CK: Normal Muscle biopsy: Normal Corticosteroid withdrawal Myalgias & arthralgias Joint effusions Rash Subjective weakness ACROMEGALY Myopathy Clinical Weakness Proximal [neuromuscular.wustl.edu]

However, a normal muscle biopsy has been reported in up 1/4 of cases with Pompe disease. [emedicine.medscape.com]

Myopathy, Endocrine

Diagnosis and management Muscle enzymes, including CK, are generally normal. At the EMG, a myopathic pattern can be observed. Muscle biopsy is frequently normal. [ncbi.nlm.nih.gov]

Late atrophy of muscles may occur. In addition, muscle biopsy findings at times may be normal. [78stepshealth.us]

Dysferlinopathy

The dystrophin was normal in all muscle biopsy. [acervodigital.ufpr.br]

In view that MABs are a subtype of pericytes, periendothelial cells present in the normal skeletal muscle, we wondered if these cells are able to participate in the normal [tesisenred.net]

The electromyography and muscle biopsy showed myopathic pattern in most of cases. An isolated neurogenic pattern in the muscular biopsy doesn't exclude the diagnosis. [acervodigital.ufpr.br]

Myotonia fluctuans

Microelectrode studies done on one muscle biopsy specimen revealed a normal chloride conductance of the muscle fiber membrane. [brain.unboundmedicine.com]

Microelectrode studies done on one muscle biopsy specimen revealed a normal chloride conductance of the muscle fiber membrane. Full Text [jamanetwork.com]

Microelectrode studies done on one muscle biopsy specimen revealed a normal chloride conductance of the muscle fiber membrane. Comment in Myotonia fluctuans. [pubmed.ncbi.nlm.nih.gov]

Welander Distal Myopathy

Additional examinations include muscle biopsy of distal muscles showing dystrophic features and prominent rimmed vacuoles. [rarediseases.info.nih.gov]

Scapular winging (40%) Course: Slow progression; Ambulation retained Cardiac: Normal Laboratory Muscle MRI: Anterior legs; Hamstrings late Muscle biopsy Fiber sizes: Varied [neuromuscular.wustl.edu]

Idiopathic Camptocormia

Muscle Biopsy Muscle biopsy reveals a myopathic pattern showing e disorganization of the normal architecture with the replacement of variable intensity of the muscular tissue [boneandspine.com]

Muscle biopsy Paraspinous muscles Variable muscle fiber size Endomysial fibrosis Little necrosis or regeneration Internal architecture: Disorganized, but same change may [neuromuscular.wustl.edu]

Serum creatine kinase levels were normal or moderately elevated. Muscle imaging showed consistent involvement of the lower paravertebral muscles and the posterior thigh. [kclpure.kcl.ac.uk]

Metabolic Myopathy

However, a normal muscle biopsy has been reported in up 1/4 of cases with Pompe disease. [emedicine.com]

Muscle biopsy showed normal light-microscopic and histochemical findings, but scattered sarcoplasmic vacuoles with storage of granular material were evident on electron microscopy [ncbi.nlm.nih.gov]

Ischemic forearm exercise test Absence of normal increase in lactate level Normal Muscle biopsy Usually shows glycogen accumulation May be normal Gene location Band 11q13 [emedicine.com]

Glycogen Storage Disease Type 10

CK was 2.5-folds increased and forearm exercise test was normal. Sections of the muscle biopsy stained with PAS showed moderate glycogen accumulation. [link.springer.com]

Ammonia rise 4x normal Muscle biopsy Subsarcolemmal & Sarcoplasmic glycogen accumulation Total glycogen: Normal or Low Variant syndrome: Congenital disorder of glycosylation [neuromuscular.wustl.edu]

 Although fibrosis can be detected in liver biopsies, this is apparently non-progressive.  No cardiac or skeletal muscle involvement is seen.  These patients have normal [slideshare.net]

Myofibrillar Myopathy Type 3

Levels of CK are normal or mildly increased. Muscle biopsy shows nonspecific myopathic changes with dystrophic changes and rimmed vacuoles in some cases. [practicalneurology.com]

CK is normal or mildly elevated and muscle biopsy demonstrates vacuolar myopathy with myofibrillar features. [ncbi.nlm.nih.gov]

Levels of CK are normal or mildly increased. Muscle biopsy shows myopathic changes and rimmed vacuoles. The causative gene in Welander’s myopathy is TIA1. [practicalneurology.com]

Acquired Amyloid Myopathy

The expression was similar in morphologically completely normal muscle biopsies obtained from clinical routine, justifying the use of such biopsies as normal reference, although [diva-portal.org]

The CK levels are normal, but the EMG shows myopathic changes. Muscle biopsy shows rods (red clusters) in the subsarcolemmal zone. [nature.com]

The initial quadriceps muscle biopsy (left panel) was normal with the exception of a few scattered necrotic fibers (not evident in this image). [hopkinsarthritis.org]

Vacuolar Neuromyopathy

Acid maltase activity of the muscle was normal, but the biopsied muscle specimen stained for lysosome-associated membrane protein-2 (LAMP-2), which has recently been reported [jstage.jst.go.jp]

Muscle biopsy showed vacuolar changes and congophilic inclusions, and molecular analysis revealed a pathogenic mutation in the DNAJB6 gene. [mayoclinic.pure.elsevier.com]

Congenital Fiber-Type Disproportion Myopathy

Nerve conduction studies were normal, and EMG normal or myopathic. In muscle biopsies, type 1 fibers were atrophied and 50% smaller than type 2 fibers. [pediatricneurologybriefs.com]

All routine laboratory data were within normal limits. EMG findings suggested myopathy. The muscle biopsy revealed fiber type disproportion with type 1 predominance. [jpatholtm.org]

The disease can be quite focal within a muscle and so sampling can be a problem. A normal biopsy does not exclude polymyositis. [sinoemedicalassociation.org]

Myopathy with Abnormal Lipid Metabolism

However, a normal muscle biopsy has been reported in up 1/4 of cases with Pompe disease. [emedicine.medscape.com]

In those cases the muscle biopsy is essentially normal except for the presence of abnormal lipid deposits in the majority of the fibers with oil-red-O stain. [bcm.edu]

Biopsy We believe that one of the reasons that statins have been used for so long without evidence of statin myopathy with normal CK is that standard muscle biopsy techniques [sdhva.com]

Ehlers-Danlos Syndrome Kyphoscoliotic Type 2

In Bethlem myopathy, muscle biopsies reveal myopathic or dystrophic changes. Collagen VI immunolabeling is often normal or shows only subtle alterations. [ncbi.nlm.nih.gov]

[…] or only slightly elevated serum creatine kinase (CK) level Histopathology of muscle biopsies showing nonspecific mild myopathic changes with increased variation in muscle [ncbi.nlm.nih.gov]

Conversely, in Ulrich congenital muscular dystrophy muscle biopsies more commonly show dystrophic features with degeneration and regeneration and replacement of muscle with [ncbi.nlm.nih.gov]

Potassium-Aggravated Myotonia

muscle biopsies, and show less decreased compound muscle action potentials when compared to patients with known mutations. [findzebra.com]

muscle biopsies, and show less decreased compound muscle action potentials when compared to patients with known mutations.[5] Table 1. [handwiki.org]

muscle biopsies, and show less decreased compound muscle action potentials when compared to patients with known mutations.[7] Table 1. [bionity.com]

X-Linked Centronuclear Myopathy

Muscle enzymes were normal. Muscle biopsy was normal. The findings in case II1-11 and case 111-14 suggest the presence of a carrier state. [docslide.com.br]

Keppen LD, Hussian M, Woody B (1986) X-linked myotubu- lar myopathy with intrafamilial variability and normal muscle biopsy in a definite female carrier. [documents.tips]

In normal muscle cells the nuclei are at the border of the cells. [znm-zusammenstark.org]

Ramsay-Hunt Cerebellar Syndrome

Histochemical and ultrastructural studies of muscle biopsies and biochemical analysis of muscle mitochondrial enzymes were normal. [link.springer.com]

Results of muscle biopsy, performed an average of 14 years after onset of the disease, were normal and showed no mitochondrial abnormalities. [ncbi.nlm.nih.gov]

We studied muscles mitochondrial function in 2 patients with RHS. [link.springer.com]

Miyoshi Myopathy Type 3

Diagnostic methods Diagnosis of MM relies on laboratory findings showing an elevated serum creatine kinase level (20 to 150 times the normal), muscle biopsy routine reveals [orpha.net]

Miyoshi Myopathy Type 2

Diagnostic methods Diagnosis of MM relies on laboratory findings showing an elevated serum creatine kinase level (20 to 150 times the normal), muscle biopsy routine reveals [orpha.net]

Distal Spinal Muscular Atrophy Type 4

A muscle biopsy showed neurogenic atrophy, while the morphology of the sural nerve was normal. [link.springer.com]

 Electromyography: loss of CMAP amplitude, diminishedconduction velocity, SNC studies are normal in pure LMNdisorder. Muscle biopsy: muscle fibers denervation could be [slideshare.net]

atrophy of groups of motor units interspersed with normal or hypertrophied motor units All the muscle fibers of a single denervated motor unit atrophy together. [amboss.com]

Secondary Myopathy

muscle biopsy CPK: normal or near normal in most patients CSF: at most, mildly raised protein Differential diagnosis Guillain-Barre syndrome other causes of predominant motor [aic.cuhk.edu.hk]

/neuronopathy Muscle biopsies reveal ragged red fibers, COX-negative fibers May also see inflammatory cell infiltrates, cytoplasmic bodies, nemaline rods Inflammatory myopathy [neurology.mhmedical.com]

Muscle biopsy may be needed if the patient’s symptoms do not respond to drug withdrawal. [now.aapmr.org]