Pseudohypertrophy, or false enlargement, is an increase in the size of an organ due to

infiltration Infiltration may refer to: Science, medicine, and engineering *Infiltration (hydrology), downward movement of water into soil *Infiltration (HVAC), a heating, ventilation, and air conditioning term for air leakage into buildings *Infiltration (me ...

of a tissue not normally found in that organ. It is commonly applied to enlargement of a muscle due to infiltration of fat or connective tissue, famously in

Duchenne muscular dystrophy Duchenne muscular dystrophy (DMD) is a severe type of muscular dystrophy that primarily affects boys. Muscle weakness usually begins around the age of four, and worsens quickly. Muscle loss typically occurs first in the thighs and pelvis fol ...

. This is in contrast with typical

muscle hypertrophy Muscle hypertrophy or muscle building involves a hypertrophy or increase in size of skeletal muscle through a growth in size of its component cells. Two factors contribute to hypertrophy: sarcoplasmic hypertrophy, which focuses more on increase ...

, in which the muscle tissue itself increases in size. Because pseudohypertrophy is not a result of increased muscle tissue, the muscles look bigger but are actually weaker. Pseudohypertrophy is typically the result of a disease, which can be a disease of muscle or a disease of the nerve supplying the muscle. Causes of pseudohypertrophy include muscle diseases: dystrophinopathies, limb-girdle muscular dystrophies,

metabolic myopathy Metabolic myopathies are Myopathy, myopathies that result from defects in biochemical metabolism that primarily affect muscle. They are generally genetic defects that interfere with muscle's ability to create energy. At the cellular level, metaboli ...

, Dystrophic myotonias, Non-dystrophic myotonias,

endocrine disorder Endocrine diseases are disorders of the endocrine system. The branch of medicine associated with endocrine disorders is known as endocrinology. Types of disease Broadly speaking, endocrine disorders may be subdivided into three groups: # Endocrin ...

s, parasitic muscle conditions,

amyloid Amyloids are aggregates of proteins characterised by a Fibril, fibrillar morphology of 7–13 Nanometer, nm in diameter, a beta sheet (β-sheet) Secondary structure of proteins, secondary structure (known as cross-β) and ability to be Staining, ...

and sarcoid myopathy, and granulomatous myositis. Neurological causes include

radiculopathy Radiculopathy, also commonly referred to as pinched nerve, refers to a set of conditions in which one or more nerves are affected and do not work properly (a neuropathy). Radiculopathy can result in pain (radicular pain), weakness, altered sensati ...

poliomyelitis Poliomyelitis, commonly shortened to polio, is an infectious disease caused by the poliovirus. Approximately 70% of cases are asymptomatic; mild symptoms which can occur include sore throat and fever; in a proportion of cases more severe sym ...

, Charcot-Marie-Tooth disease,

spinal muscular atrophy Spinal muscular atrophy (SMA) is a rare neuromuscular disorder that results in the loss of motor neurons and progressive muscle wasting. It is usually diagnosed in infancy or early childhood and if left untreated it is the most common genetic ...

. Pseudohypertrophy can be broken up into the following roots, suffixes, and prefixes: * Pseudo means 'false' or 'fake'. The etymology is from the Greek word (), which means to lie or deceive. * hyper means 'extreme' or 'beyond normal'. The etymology is from the Greek word (), which means over, above; beyond, to the extreme. * trophy means 'nourishment', or 'development'. The etymology is from the Greek word (), which means food, nourishment. The term was used by

Duchenne de Boulogne Guillaume-Benjamin-Amand Duchenne (de Boulogne) (September 17, 1806 in Boulogne-sur-Mer – September 15, 1875 in Paris) was a French neurologist who revived Galvani's research and greatly advanced the science of electrophysiology. The era of mo ...

in his description of

in one of his works "paralysie musculaire pseudo-hypertrophique."

References

{{Reflist Symptoms and signs: Nervous system