ICD-11 and Dissociative neurological symptom disorder:
For DSM-5, the disorder term is
"Functional Neurological Symptom Disorder (Conversion Disorder)" and it is listed under the
Somatic symptom and Related Disorders disorder category block (the block under which
Somatic symptom disorder is also located).
There has been a long-standing tug of war between Dr Jon Stone, Prof Raad Shakir and the WHO over which chapter the WHO's equivalent of FNSD would be located under for ICD-11.
The lead for the revision of the
Mental, behavioural or developmental disorders chapter wanted to retain the ICD-11 equivalent of DSM-5's FNSD within the MH chapter.
Prof Raad Shakir was the chair of the ICD-11
Topic Advisory Group for Neurology. Stone and Shakir lobbied WHO for relocating the ICD-11 equivalent of DSM-5's FNSD to the
Diseases of the nervous system chapter - not because they consider this diagnosis to be a neurological diagnosis but because, amongst other reasons, neurologists often have these patients referred to them.
They also published a position paper in 2014 [1] setting out their rationales for recommending that this disorder category should be relocated from under the
Dissociative disorders and parented under the
Diseases of the nervous system chapter or listed in both chapters:
1 Stone, J., Hallett, M., Carson, A., Bergen, D., & Shakir, R. (2014). Functional disorders in the Neurology section of ICD-11: A landmark opportunity. Neurology, 83(24), 2299–2301. doi:10.1212/WNL.0000000000001063
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4277679/
At one point, for the ICD-11 Beta draft, the disorder category
was relocated under the
Diseases of the nervous system chapter.
Later, the category was dragged back under the MH chapter, but with the concession of secondary parenting under the
Diseases of the nervous system.
And that is how it stood for the initial release of the implementation version of ICD-11, last June:
https://icd.who.int/browse11/l-m/en#/http://id.who.int/icd/entity/1069443471
06 Mental, behavioural or neurodevelopmental disorders
Dissociative disorders
> 6B60 Dissociative neurological symptom disorder
>>6B60.0 Dissociative neurological symptom disorder, with visual disturbance
>>6B60.1 Dissociative neurological symptom disorder, with auditory disturbance
>>6B60.2 Dissociative neurological symptom disorder, with vertigo or dizziness
>>6B60.3 Dissociative neurological symptom disorder, with other sensory disturbance
>>6B60.4 Dissociative neurological symptom disorder, with non-epileptic seizures
>>6B60.5 Dissociative neurological symptom disorder, with speech disturbance
>>6B60.6 Dissociative neurological symptom disorder, with paresis or weakness
>>6B60.7 Dissociative neurological symptom disorder, with gait disturbance
>>6B60.8 Dissociative neurological symptom disorder, with movement disturbance
>>>6B60.80 Dissociative neurological symptom disorder, with chorea
>>>6B60.81 Dissociative neurological symptom disorder, with myoclonus
>>>6B60.82 Dissociative neurological symptom disorder, with tremor
>>>6B60.83 Dissociative neurological symptom disorder, with dystonia
>>>6B60.84 Dissociative neurological symptom disorder, with facial spasm
>>>6B60.85 Dissociative neurological symptom disorder, with Parkinsonism
>>>6B60.8Y Dissociative neurological symptom disorder, with other specified movement disturbance
>>>6B60.8Z Dissociative neurological symptom disorder, with unspecified movement disturbance
>>6B60.9 Dissociative neurological symptom disorder, with cognitive symptoms
>>6B60.Y Dissociative neurological symptom disorder, with other specified symptoms
>>6B60.Z Dissociative neurological symptom disorder, with unspecified symptoms
If you look at chapter
08 Diseases of the nervous system you will see
Dissociative neurological symptom disorder displaying in black in the
Foundation Component with its two parents listed:
https://icd.who.int/dev11/f/en#/http://id.who.int/icd/entity/1069443471
Dissociative neurological symptom disorder
Parent(s)
and here in the
Mortality and Morbidity Statistic Linearization for the Diseases of the nervous system chapter:
https://icd.who.int/browse11/l-m/en#/http://id.who.int/icd/entity/1296093776
there is a listing right near the end of the chapter for
6B60 Dissociative neurological symptom disorder
the last term listed directly above what are known as the "residual categories" (in brown in the Linearization)
8E7Y Other specified diseases of the nervous system
8E7Z Diseases of the nervous system, unspecified
If you click on the
6B60 Dissociative neurological symptom disorder category link, it redirects to the category's primary parent location within the MH chapter:
https://icd.who.int/browse11/l-m/en#/http://id.who.int/icd/entity/1069443471
(this category displays as "Greyed out" in the MMS Linearization for the
Diseases of the nervous system chapter indicating that this category is
secondary parented in this location and
primary parented in another chapter.)
There was also much debate over what terminology would be used for ICD-11. In 2014, the term favoured by Stone, Shakir et al, had been
"Functional disorders of the nervous system."
However, the lead for the revision of the MH chapter was keen that for ICD-11, the term should retain the word "Dissociative" within its disorder name.
So for ICD-11, although under
Synonyms, the following are listed:
Synonyms
- Functional neurological disorders
- Functional neurological symptom disorder (Ed: this is the DSM-5 term)
- Conversion disorder
WHO is going forward with the term,
"Dissociative neurological symptom disorder" - though the Beta draft went through various iterations of the term before
"Dissociative neurological symptom disorder" was eventually approved by WHO.
Note that in the Stone et al paper referenced above, the authors wrote:
"In ICD-10, functional disorders are commonly found within the parent specialties most likely to see the patients. For example, irritable bowel syndrome is classified in the gastrointestinal section and fibromyalgia within the rheumatology section. Neurology has lagged behind in this respect.
Gastroenterologists, for example, have been refining their understanding and classification of functional gastrointestinal disorders with international consensus since the mid-1970s.5 The Rome Foundation classification for functional gastrointestinal disorders is now in its third revision and has been provisionally adopted on a wholesale basis for ICD-11.
"ICD-11 offers a new, landmark opportunity to bring functional disorders back within the legitimate domain of neurology. We have proposed a category within the Neurologic section in which all of the functional disorders involving motor and sensory function can be listed and coded (including nonepileptic attacks) (table). We suggest that, like other conditions shared between neurologists and psychiatrists, such as Tourette syndrome and dementia, psychiatry retains a code for functional disorders, preferably matching that found in neurology."
It
is the case that for ICD-11, IBS has been retained in the chapter,
Diseases of the digestive system, under the
Functional gastrointestinal disorders block. However, the IASP/WHO Chronic pain task force had proposed to shift IBS under the new
Chronic primary pain disorders block, within the
Symptoms, signs chapter, under
Chronic primary visceral pain - a proposal which WHO has rejected. (The IASP task force has since requested that IBS is secondary parented to
Chronic primary visceral pain.)
In May 2015,
Fibromyalgia was relocated from
Diseases of the musculoskeletal system or connective tissue and placed under the new
Chronic primary pain block, as an inclusion under
Chronic widespread pain, from which it takes its code, and it no longer has a discrete code assigned to it, as it had in ICD-10.
So for ICD-11, the term is
Dissociative neurological symptom disorder (a term which is being challenged by some FND advocacy orgs) and it remains primary parented in chapter
06 Mental, behavioural or neurodevelopmental disorders under the class:
Dissociative disorders, with secondary parenting within chapter
08 Disorders of the nervous system.
In ICD-11 it is the primary parent chapter location that dictates the code, so
Dissociative neurological symptom disorder displays with code
6B60 in both locations.