Peripheral neuropathies Flashcards
What are the different types of polyneuropathies?
- mononeuropathy- carpal tunnel syndrome
- polyneuropathy-diabetic neuropathy(symmetrical involvement of peripheral nerves)
- Mononeuropathy multiplex- multiple peripheral nerves simultaneously
What is the prevalence of peripheral neuropathy in patients above 55 years?
> 8%
What is the classification of polyneuropathies?
- acute <4 weeks
- subacute 4 weeks to 12 weeks
- chronic polyneuropathies: >12 weeks and often not reversible
What are the causes of acute polyneuropathies?
- Guillain Barre syndrome
- pophyria
- Thiamine deficiency neuropathy
What are the causes of suabacute neuropathies?
- Thiamine deficiency neuropathy
What are chronic neuopathies causes?
- Diabetic polyneuropathy
- Hiv
- Nutritional deficencies
- Inflammatory- paraproteinemic
What are the clinical features of chronic polyeneuropathy?
symptoms:
1. numbness, paraesthesia, pain, decreased temperature or pain sensation, weakness, incoordination
2 signs: distal weakness, distal sensory loss, distal reflex loss
What is Guillain Barre syndrome?
Usually occurs after 3 days to 6 weeks post infection of the respiratory tract or GIT
- Occurs in any age
- mechanism is molecular mimicry
What is AIDP?
acute inflammatory demyelinating polyneuropathy
This is an inflamatroy attack of the myelin sheath and is the commonest form of GBS
What is the least common type of Guillain Barre Syndrome?
- Axonal forms(AMAN and AMSAN) which stands for antibody mediated attack at nodes of ranvier
- 10% of cases
What are the clinical features of GBS?
- Ascending paralysis usually proximal and sital weakness with absent reflexes
- usually no sphicter dysfunction
- facial weakness bilaterally
When do the patients present with the peak weakness?
50% will reach within 2 weeks and others within 4 weeks
How do we diagnose GBS?
- csf-albumincytological studies
2. nerve conduction studies
How do we treat GBS?
- SUPPORTIVE
- respiratory ventilation or intubation as needed
- bulbar function(risk of aspiration)
- rehabilitation
- venous thromboembolitic prevention-heparin
- ulcer prevention(turn patient often) - SPECIFIC
- plasma exchange
- IV immunoglobulin
What is the mortality rate of GBS?
2-8% mostly killed by sepsis, pulmonary embolism
What will we find on CSF for patients with GBS nd HIV?
higher amount of lymphocytes- about 100 lymphocytes
What is porphyria?
Group of inherited disorders(autosomal dominant) of haem synthesis
What is the clinical presentation of porphyria?
- Abdominal pain
- skin lesions
- seizures and delirium
- Polyneuropathy with global weakness
- acute intermittent porphyria
Who typically gets Porphyria?
young women who experienceacute attacks
What are the 4 p’s?
- painful abdomen
- polyneuropathy
- psychological disturbances
- port wine coloured urine
How do we treat porphyria?
glucose and heme
What is paraneoplastic neuropathy?
This can present before the cancer and can help us have early detection and cure
-predominantly sensory symptoms
What complications do pts with diabetes present with?
- polyneuorpathy
- nephropathy
- retinopathy
What are the clinical features of diabetic neuropathy?
- slow progression over the years
- insidious onset of numbness, paraesthesia, burning pain
- starts distally and moves proximally
- often associated with carpal tunnel syndrome
What complications can the sensory loss due to DM polyneuropathy cause?
- diabetic foot because of sensory loss
- impaction of foreign objects
- foot ulcers
- Charcot joint
What is the treatment of DM polyneuropathy?
1.Control of glucose
2. foot care
3. pain management
Even though we can control glucose the damage is often irreversible
What is alcohol related polyneuropathy?
- slow and progressive over weeks and months
- affects the lower limbs more than the upper limbs
- usually sensory features like numbness, paraesthesia, 40% experience pain
What causes the polyneuropathy in alcohol users?
- toxic effects of the alcohol
2. vitamin deficiencies
What is the culprit protein that causes alcohol related polyneuropathy?
- acetyldehyde
What are the 2 types of alcohol polyneuropathy are there?
- alcohol polyneuropathy
- more sensory than motor
- poor response to treatment with thiamine
- slowly progressive - thiamine deficiency polyneuropathy
- presents with more motor symptoms
- good response to thiamine
- acute or subacute
What is neuropathy of chronic renal failure?
- insiduous and slow onset
- weakness, reduced reflexes, paraesthesia, atrophy
- develops at GFR <12ml/min
- only occurs in end stage kidney disease
What is the treatment of chronic renal disease polyneuropathy?
Does not respond to dialysis so renal transplant is necessary
What is toxic neuropathy?
caused by medication
- chemotherapy
- ARV’S
- Antibiotics like quinolones
What are the 3 conditions associated with HIV polyneuorpathy?
- distal sensory polyneuropathy(most common)-disabling pain, paraesthesia
- demyelinating polyneuropathy-GBS
- diffuse infiltrative lymphocytosis syndrome-RARE
How does B12 deficiency present?
90% or more presen with myeloneuropathy
What are the clinical features of B12 NEUROPATHY?
- Polyneuropathy
- loss of weakness
- atrophy of distal muscles
- loss of reflexes - Subacute combined degeneration of the cord:
- UMN bladder symptoms
- brisk reflexes
- loss of proprioception - beefy red tongue
What is important about vit B12 deficiency?
We must always investigate the cause and check it is not caused by pernicious anaemia, atrophic gastritis which is problems with absorption
How do we treat Vit B12?
We can inject intramuscular B12 for life
What is CIDP?
It is chronic inflammatroy demyelinating polyneuropathy
- inflammatory demyelination of peripheral nerves and roots
- responds to steroid treatment and IV immunoglobulins
What are the clinical features of chronic inflammatory demyelnating polyneuropahy?
- proximal and distal weakness
- sensory loss and paraesthesia in feet and hands
- global arreflexia
- there’s already atrophy of hand muscles
What are the causes of mononeuropathy multiplex?
- vasculitis
2. diabetes
