# Chiari Malformation Question



## jhartung (Sep 15, 2015)

Hi All,

I am new to neurosurgery coding and I noticed that there are 4 different codes for Chiari Malformation based on what type of malformation the patient has. However, if the physician just documents Chiari Malformation without listing type I, type II, etc. is there a default code to use or can this not be coded at all without the type specified? 

Any help is greatly appreciated!


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## tochrist@childrensnational.org (Dec 10, 2018)

*Chiari malformation four types*

*Per coding clinic,* 

Prior to October 1, 1994, all forms of this anomaly were indexed to 741.0, Spina bifida.  Effective Octobter 1, 1994, revisions have been made to the index and the tabular to give direction as to the proper code assignment for each type of Chiari malformation.  

*So I would query the provider for the specificity.*

Arnold-Chiari obstruction or syndrome
Type 1- 348.4, Type II (see also spina bifida) 741.0, Type III 742.0 and Type IV 742.2 

Hope this helps.. 

ICD-10 Chiari's

                   disease or syndrome(hepatic vein thrombosis) I82.0

                   malformation
                                   Type I G93.5
                                   Type II- See Spina bifida 

                   net Q24.8

Budd-Chiari syndrome

   Hepatic vein thrombosis  I82.0

 Arnold-Chiari syndrome-

Type I Compression of brain(stem) G93.5 

Rare congenital anomaly often associated with spina bifida.  The spinal cord is separated into longitudinal halves by a bony, cartilaginous or fibrous septum, each half surrounded by a dural sac.

 Type II Q07.0-

Q07.00 Arnold-Chiari syndrome without spina bifida
Q07.01 with spina bifida
Q07.02 with hydrocephalus 
Q07.03 with spina bifida and hydrocephalus

Type III Q01.- 

Q01.0 Frontal encephalocele
Q01.1 Nasofrontal
Q01.2 Occipital 
Q01.8 Encephalocele of other sites
Q01.9 Encephalocele, unspecified.

Type IV Q04.8

Aronold-Chiari malformation syndrome, type IV
Macrogyria

My question is which code do you use for Chiari malformation 1.5? It states on radiopaedia.org That Chiari 1.5 malformation likely results from a Chiari 1 malformation combined with a smaller posterior fossa that in turn leads to overcrowding and caudal displacement of the medulla.

I thought I saw a coding clinic on it and can't find it.

Have a great day and God Bless!

T~ aka Mr. Christian


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