Diabetic Neuropathy Flashcards
Diabetic Amyotrophy
Diabetic amyotrophy is also known as proximal diabetic neuropathy. The latter term is probably more useful as it describes more accurately the aetiology of the condition.
Typical features include
pain is usually in the first symptom, often in the hips or buttocks
this is followed by weakness, for example difficulty getting out of a chair
Diabetic Amyotrophy - Example Question
A 72 year old male from Dominican Republic presents with a 4 month history of constant bilateral anterior thigh pain and lower limb weakness, starting first in the left before progressing to bilateral symptoms. He reports being an extremely active man prior to these symptoms, continually to work as a landscape gardener until four months ago, and now he is wheelchair and bed-bound. He denies any history of trauma to his hips, previous tuberculosis infection or contact with heavy metals. His thigh pain appears excruciating, described as burning in nature along the anterior aspects of both thighs to the origin of the patella tendon bilaterally. He reports no recent weight loss, pyrexia or skin changes. His past medical history includes hypertension, hypercholesterolaemia, hypothyroidism and type 2 diabetes mellitus (diagnosed 6 years ago).
On examination, the patient has mildly reduced muscle bulk in bilateral hip flexors and bilateral fasciculations in both thighs. Examination of power demonstrates 2+/5 bilaterally in hip flexion 4+/5 hip extension bilaterally and 5/5 all other lower limb movements. Sensory examination revealed reduced sensation to cotton wool in both thighs and distal feet, reduced proprioception in both toes. Reflexes were 2+ at both knee jerks, absent ankle jerks bilaterally and downgoing plantars bilaterally. His blood tests are as follows:
Hb 13.4 g/dl
Platelets 383 * 109/l
WBC 4.5 * 109/l
Na+ 135 mmol/l K+ 4.6 mmol/l Urea 8.6 mmol/l Creatinine 112 µmol/l CRP 1 mg/l Creatine kinase 116 IU/l (50-335) HbA1c 68 mmol/mol TSH 2.1 mu/l Free T4 15.4 nmol/l
A MRI scan was performed of his lumbosacral plexus, demonstrating no appreciable structural lesion. Nerve conduction studies and EMG are awaited.
What is the optimal treatment?
> Optimise diabetic control Riluzole Intravenous immunoglobulin Intravenous methylprednisolone Lumbar puncture
The positive symptoms include bilateral proximal myopathy, severe neuropathic pain in thighs and absence of lumboscral structural lesions, in a HIV negative patient, the diagnosis if most likely diabetic amyotrophy. The onset of proximal pain as a result of a microvascular lumbosacral plexopathy is usually asymmetric before becoming more symmetrical.
The lack of upper motor neurone signs make this unlikely to be motor neuron disease (and hence requiring riluzole). The involvement of sensory components rule out multifocal motor neuropathy with conduction block, typically responsive to IVIg. The proximal location of the symptoms and prominent neuropathic pain is classical of amyotrophy instead of chronic inflammatory demyelinating polyneuropathy (CIDP), for which intravenous methylprednisolone can be therapeutic.
The best treatment for diabetic amyotrophy is to optimise blood sugar control and symptomatic treatment neuropathic agents. Most patients report at least partial, if not full motor recovery and much improved pain symptoms
Diabetic Amyotrophy - Presentation
The positive symptoms include bilateral proximal myopathy, severe neuropathic pain in thighs and absence of lumboscral structural lesions, in a HIV negative patient, the diagnosis if most likely diabetic amyotrophy.
The lack of upper motor neurone signs make this unlikely to be motor neuron disease (and hence requiring riluzole). The involvement of sensory components rule out multifocal motor neuropathy with conduction block, typically responsive to IVIg.
The proximal location of the symptoms and prominent neuropathic pain is classical of amyotrophy instead of chronic inflammatory demyelinating polyneuropathy (CIDP), for which intravenous methylprednisolone can be therapeutic.
The best treatment for diabetic amyotrophy is to optimise blood sugar control and symptomatic treatment neuropathic agents. Most patients report at least partial, if not full motor recovery and much improved pain symptoms
