Disorders of muscle tone of newborn (P94)
ICD-10 code P94 addresses disorders affecting the muscle tone of newborns, including conditions where muscle strength or control is unusually high or low. These codes are essential for identifying specific neonatal muscle tone abnormalities such as transient neonatal myasthenia gravis (P94.0), congenital hypertonia (P94.1), and congenital hypotonia (P94.2).
This section covers a range of muscle tone disorders noted at birth. For instance, transient neonatal myasthenia gravis (also called neonatal neuromuscular disorder or myasthenia gravis) refers to temporary muscle weakness caused by maternal antibodies and is coded as P94.0. Congenital hypertonia involves increased muscle tone present from birth (P94.1), whereas congenital hypotonia (P94.2) features decreased muscle tone, often also called floppy infant syndrome, and is linked with various developmental syndromes. Other codes in this category, like P94.8 for other muscle tone disorders, include conditions such as neonatal hypokinesia or head lag, while P94.9 is used when muscle tone disorder is unspecified but clearly present. Using these ICD-10 codes helps healthcare professionals accurately classify neonatal muscle issues to guide diagnosis and treatment.
Clinical Terms
The following clinical terms provide additional context, helping users better understand the clinical background and common associations for each diagnosis listed in this section. Including related terms alongside ICD-10-CM codes supports coders, billers, and healthcare professionals in improving accuracy, enhancing documentation, and facilitating research or patient education.
Cystinuria
An inherited disorder due to defective reabsorption of CYSTINE and other BASIC AMINO ACIDS by the PROXIMAL RENAL TUBULES. This form of aminoaciduria is characterized by the abnormally high urinary levels of cystine; LYSINE; ARGININE; and ORNITHINE. Mutations involve the amino acid transport protein gene SLC3A1.
Myasthenia Gravis
A disorder of neuromuscular transmission characterized by fatigable weakness of cranial and skeletal muscles with elevated titers of ACETYLCHOLINE RECEPTORS or muscle-specific receptor tyrosine kinase (MuSK) autoantibodies. Clinical manifestations may include ocular muscle weakness (fluctuating, asymmetric, external ophthalmoplegia; diplopia; ptosis; and weakness of eye closure) and extraocular fatigable weakness of facial, bulbar, respiratory, and proximal limb muscles. The disease may remain limited to the ocular muscles (ocular myasthenia). THYMOMA is commonly associated with this condition.
Myasthenia Gravis, Autoimmune, Experimental
Any autoimmune animal disease model used in the study of MYASTHENIA GRAVIS. Injection with purified neuromuscular junction acetylcholine receptor (AChR) (see RECEPTORS, CHOLINERGIC) components results in a myasthenic syndrome that has acute and chronic phases. The motor endplate pathology, loss of acetylcholine receptors, presence of circulating anti-AChR antibodies, and electrophysiologic changes make this condition virtually identical to human myasthenia gravis. Passive transfer of AChR antibodies or lymphocytes from afflicted animals to normals induces passive transfer experimental autoimmune myasthenia gravis. (From Joynt, Clinical Neurology, 1997, Ch 54, p3)
Myasthenia Gravis, Neonatal
A disorder of neuromuscular transmission that occurs in a minority of newborns born to women with myasthenia gravis. Clinical features are usually present at birth or develop in the first 3 days of life and consist of hypotonia and impaired respiratory, suck, and swallowing abilities. This condition is associated with the passive transfer of acetylcholine receptor antibodies through the placenta. In the majority of infants the myasthenic weakness resolves (i.e., transient neonatal myasthenia gravis) although this disorder may rarely continue beyond the neonatal period (i.e., persistent neonatal myasthenia gravis). (From Menkes, Textbook of Child Neurology, 5th ed, p823; Neurology 1997 Jan;48(1):50-4)
Myasthenic Syndromes, Congenital
A heterogeneous group of disorders characterized by a congenital defect in neuromuscular transmission at the NEUROMUSCULAR JUNCTION. This includes presynaptic, synaptic, and postsynaptic disorders (that are not of autoimmune origin). The majority of these diseases are caused by mutations of various subunits of the nicotinic acetylcholine receptor (RECEPTORS, NICOTINIC) on the postsynaptic surface of the junction. (From Arch Neurol 1999 Feb;56(2):163-7)
