Neuro - PNS - Metabolic and Toxic Disease Flashcards
1
Q
Diabetic Neuropathy
A
- a peripheral neuropathy affecting sensory, motor, and autonomic fibers in diabetic patients.
- Typically refers to a distal symmetrical sensorineural neuropathy, however, other forms of neuropathy are also associated with diabetes. These rarer forms include:
- Autonomic neuropathy
- focal or multifocal asymmetric neuropathy
- small fiber and painful neuropathy
- regional neuropathic syndromes
2
Q
Diabetic Neuropathy - Epidemiology
A
- An estimated 10-65% of patients with diabetes have some form of peripheral neuropathy after 25 years of the disease
- 66% of type I
- 59% of type 2
- Most common worldwide form of peripheral neuropathy
- U.S prevalence is est. at 6.5%
- Up to 8% of diabetics have peripheral neuropathy at the time their diabetes is diagnosed
- At 25 year post diagnosis - 50% of cases have peripheral neuropathy
3
Q
Diabetic Neuropathy - Pathogenesis
A
- Abnormal activity of four pathways are thought to underlie the genesis of peripheral neuropathy
- increased polyol pathway flux
- increased intracellular formation of advanced glycation end-products
- activation of protein kinase C elevating the expression of proinflammatory molecules
- increased flux in the hexoamine pathway
- All pathways ultimately resilt in vascular insufficiency, the elvation of free radical production, and the loss of free radical scavengers
4
Q
Diabetic Neuropathy - Pathology
A
- Axonopathy is prominent finding
- Some segmental demyelination
- Significant loss of small fibers, lesser degree of large fiber involvement
- Vascular abnormalities in the nerve as well
- Autonomic dysfunction
5
Q
Diabetic Neuropathy - Diabetic Sensorimotor polyneuropathy (DSPN)
A
- small and large fiber sensory, autonomic, motor types
- Insidious & progressive
- SxS: numbness, tingling, buzzing, burning, prickling in toes & feet
- conversion of glucose to sorbitol causing demyelination & axonal loss
- Other hypotheses: insufficient blood flow, altered fatty acid metabolism, decreased nerve growth factor, oxidative stress
6
Q
Diabetic Neuropathy - Asymmetric Diabetic Neuropathy
A
- Abducens involvement
- sudden onset of diplopia
- spontaneous recovery in 3-5 mon without treatment
- Oculomotor involvement
- intense retro-orbital pain with diplopia, u’l ptosis, restriction of medial upgaze palsy
- pupil is nearly always spared
- Bell’s palsy
- Limbs: median, ulnar, fibular, lateral cutaneous entrapment neuropathies
7
Q
Diabetic Neuropathy - DIabetic Truncal radiculoneuropathy
A
- Abrupt onset of severe thoracic spine, flane, rib, or upper abdomen pain
- contact hyperesthesia
- commonly occurs with DSPN
8
Q
Diabetic Neuropathy - Diabetic Amyotrophy
A
- Abrupt onset of pain to anterior thigh, sometimes buttock, lower back
- b/l with one side worse than other
- hemiparesis
- EDx: L2-L4 radiculopathy, lumbar plexopathy, femoral neuropathy
9
Q
Diabetic Neuropathy - Diabetic Neuropathic cachexia
A
- uncommon painful sensory neuropathy in DMI
- Ascending pain with allodynia (pain from normally unpainful stimuli)
- favorable progress with glucose control
10
Q
Diabetic Neuropathy - Insulin Neuritis
A
- pain due to insulin treatment
11
Q
Diabetic Neuropathy - Presentation
A
- insidious and progressive
- Numbness and painless tingling, typically in distal extremities
- Pain is prominent feature, pain worsens at night
- Begins with toes, and ascends to calves before beginning in fingers and ascending arms (stocking, glove distribution)
- Small pain fibers can be severely affected, although large pain fibers are also involved.
- mild distal muscle weakness and atrophy > gait disturbance
- Tendon reflexes typically depressed
- Autonomic dysfunction typical present as well: impotence, difficulty voiding, sweating, orthostatic hypotension
12
Q
Diabetic Neuropathy - DIagnostic testing
A
- Diagnosis typically made on clinical findings
- Nerve conduction studies can be helpful but not definitive
- Biopsy generally not indicated
13
Q
Diabetic Neuropathy - Treatment
A
- No definitive pharmacological treatment
- Slow the course of the disease with tighter control of blood glucose levels
- Numerous free radical scavengers have been tried but have not experienced much therapeutic success
- Pain Management
14
Q
Diabetic Neuropathy - Management with complications
A
- Pain control
- Tricyclic antidepressants
- tramadol
- Anticonvulsants
- Arcotic agents
- Foot ulcerations (probably due to decreased sensation and diffuse vascular injury)
15
Q
Diabetic Neuropathy - Prevention
A
- Foot hygiene
* Tight control of blood glucose levels
