Chronic Denervation or ‘Neurogenic Disorder’

I am 53 and have a mild neuromuscular disorder but with debilitating fatigue. In 2007 I was diagnosed with Chronic Denervation or ‘Neurogenic Disorder’.

Q1: What is my ‘muscle fatigue’ (see below) called: is it weakness, fatigue, or exercise intolerance and is this typical of “chronic neurogenic change”?

Q2: Given that my mental fatigue has not abated in 5 years; my ‘exercise intolerance’ and muscle pain/fatigue is marginally worse should I pursue for other causes ie metabolic disorders?

Exercise intolerance/fatigue/weakness occurs with brief & intense i.e. repetitive hand grips, signing name, beating eggs, rapid foot movements, chewing large objects; muscle becomes stiff, fatigued painful lacks ‘strength’ with-in 10 – 30 seconds. If stop and rest i.e. swap hands can continue. Happened since childhood - no 'attacks' or episodes all the time.
Moderate exercise usually well tolerated although with some lasting fatigue and discomfort. No eye involvement. No ischemic exercise tests carried out.
‘Static exercise’ i.e. maintaining erect posture, standing still in one spot, etc. causes stiffness and a fatigueing/crampy pain. No evidence of myoglobinuria.
Chronic fatigue for +20 years – progressed from mild to current debilitating form.
Have had 2 major health 'crisis' or setbacks. First at age 7 yrs hospitalised with fever including encephalitis, 'suspected brucellosis' followed 12 months 'very sick' with muscle pain, ‘arthritis’ etc.
Second: 2006 onset of greater fatigue and cognitive issues, muscle aches, nerve pain, fasciculations, muscle stiffness, enlarged liver, etc.; Meds inc Epilim (sodium valproate) for ‘mood stabilizer?’; various antibiotics for suspected Q Fever; Mildly elevated CK 232 U/L
2007 diagnosed with Chronic Denervation or ‘Neurogenic Disorder’ after SFEMG & muscle biopsy for mito cytopathy – not screened for metabolic disorders – screen negative for KSS/CPEO). Tested Ddx: ALS, MS, MG, heart disease, etc.

[Shiv Kumar, MD]

Dear Aurelius4Star,

Thanks for the query.

From the description, it looks like you are suffering from chronic (childhood onset) minimally progressive neuromuscular disorder manifesting as excessive fatigue, exercise intolerance, stiff muscles, fasciculations with bladder involvement. However, the available work up does not reveal the cause of the syndrome.

So I personally feel that before proceeding for a detailed work up, a proper syndromic diagnosis is required. So I would suggest that you meet a good neurologist and proceed for a detailed evaluation based on the examination findings.

Let me know if I have missed out any other concern in your question.

Yet again, I duly appreciate your query to me, I do hope that you have found something useful to help you and I shall be glad to answer any further apprehensions.

Thank you for using MedHelp's "Ask an Expert" Service, where we feature some of world's renowned medical experts in their fields. Millions have benefitted from our service to get personalized advice for them and for their loved ones.

Best Regards,
Dr. Shiva Kumar R

[Aurelius4Star]

Thank you for your consideration. I have seen two senior neuroloogists - one diagnosed chronic fatigue & fibromyalgia, the second said "no fibromyalgia but 'chronic denervation' as would be seen in post-polio but I would not have had polio" - he did SFEMG which confirmed earlier muscle biopsy result for chronic denervation. There is no bladder involvement.
Could you please answer my questions:

Q1: What is my ‘muscle fatigue’ (see description above) called: is it weakness, fatigue, or exercise intolerance and is this typical of “chronic denervation” (to be more specific)?

Q2: Given that my mental fatigue has not abated in 5 years; my ‘exercise intolerance’ and muscle pain/fatigue is marginally worse should I pursue for other causes ie metabolic disorders?

Metabolic muscle disorders such as glycogen & lipid storage disorders & mitochondrial enzyme deficiencies are often linked to premature exercise intolerance. This is why I want to know what is the correct descriptor for my muscle condition (rapid fatigue) so I can clearly explain it to my doctor.
Thank you

[Shiv Kumar, MD]

Dear Aurelius4Star,

Thanks for the query.

From the information that you have provided,  I would like to indicate that chronic denervation is a non-specific finding and can be seen in many conditions. SFEMG (Single-fiber electromyography) was done to rule out the possibility of Myasthenia in you.

Chronic denervation without features of metabolic myopathies rules out the possibility of storage disorders in you. However, the possibility of mitochondrial disease cannot be ruled out.

So I personally feel that a further work up for metabolic disorders is likely to be negative. Chronic denervation on EMG (Electromyography) and muscle biopsy suggests the possibility of nerve disease rather than a muscle problem. As we have excluded treatable causes, physiotherapy would be the best option for you.  


Let me know if I have missed out any other concern in your question.

Yet again, I duly appreciate your query to me, I do hope that you have found something useful to help you and I shall be glad to answer any further apprehensions.

Best Regards,
Dr Shiva Kumar R

[Aurelius4Star]

Thank you for your answers, that is very helpful and I will discuss this with my neurolgist at my next appointment