Neuropathic Pain - Block 2 Flashcards
What are the types of PNS neuropathic pain?
- DIabetic peripheral neuropathy
- Trigeminal neuralgia
- Postherpetic neuralgia
Types of neuropathic pain in the CNS?
Fibromyalgia
What is the most common neurologic complication of diabetes?
Diabetic Peripheral Neuropathy
What is Diabetic Peripheral Neuropathy?
Gradual loss of integrity of the longest nerve fibers -> sensory loss and risk of foot ulcers
What are the risk factors of DPN?
- Advanced age
- HTN
- PVD
- SMoking
- DLD
- Poor glucose control
- Long duration of diabetes
- Heavy intake of alcohol
What is the cause of DPN?
Uncontrolled hypergycemia damages nerves and capillaries -> loss of nerve fibers due to impaired blood flow -> impaired nerve sensitivity or pain
What are the presentations of DPN?
- Numbness, tingling, burning
- Affects feet/legs first, then hards/arms
- Sx often worse at night
- Foot ulcers/infections
How do you diagnose DPN?
- Physical exam
- Review med hx
- Review of sx
- Monofilament: test sensitivity to touch
- Sensory testing: response to vibration, temp changes
Preventive care for DPN?
- Glycemic control
- Risk factor mod
- Foot care
- Safety and falls precautions
- B12 def correction
How long should trial duration of DPN tx last?
2-3 months
What are your first line tx for DPN?
SNRIs: duloxetine, venlafaxine
TCAs: amitriptyline, desipramine, nortriptyline
Topical: capsaicn 8% patch
What are the first line alts for DPN tx?
Gabapentinoids: Gabapentin, pregabalin
What to do in inadequate response to initial DPN therapy?
Add a second first-line drug from a different medication class (pregabalin + duloxetine)
OR
Switch to an alternative medication among the first line options
What combo must you avoid for DPN?
SNRI + TCA -> serotonin syndrome
What are topical tx for DPN?
Capsaicin cream 0.075%
Lidocaine patch
Transcutaneous nerve stimulation
Spinal cord stimulation
Acupuncture
What is not recommended for DPN?
Opioids and topiramate
What is trigeminal neuralgia?
Recurrent brief episodes of unilateral electric shock like pains
* Pain is abrupt in onset and termination located in the distribution of one or more divisions of the trigeminal nerve
* Triggered by innocuous stimuli
What are the RF of TN?
HTN and migraine
What is the cause of TN?
Compression of the trigeminal nerve at its root by an aberrant loop of an intracranial artery:
1. Tumor
2. AV malformation
3. Aneurysm
4. MS plaque
What are the clinical presentation of TN?
- Attacks may recurr, 100 times a day
- Lancinating, stabbing, excruciating, electric
- Chewing, brushing the teeth, smiling, or even wind blowing up against face
- Unilateral
How do you diagnose TN?
- Primarily paroxysms of pain in the distribution of the trigeminal nerve
- Differentiate from other disorders that cause facial pain
- MRI enables visualization of trigeminal nerve and small adjacent lesions
What is the initial tx for TN?
First line: Carbamazepine, oxcarbazepine