4- Peripheral Neuropathies & ALS Flashcards
Compression of the median nerve causing carpal tunnel syndrome is the most common example of what type of nerve pathology?
(others: peroneal = foot drop, ulnar = hand weakness, radial = wrist drop)
Mononeuropathy (single nerve affected)
Diabetes affecting a combination of individual nerves or thoracic neuropathy causing problems with both the radial and ulnar nerves are examples of what type of nerve pathology?
Mononeuropathy multiplex
What type of neuropathy is commonly seen in distal nerve distributions?
Polyneuropathy
Compression or entrapment of a nerve will result in what type of nerve pathology?
Mechanical
What is neuropraxia and what nerve pathology is it a/w?
Damage to axons w/ NO nerve damage- ex. arm falls asleep
A/w mechanical pathology
Ischemic damage by venous disease (polyarteritis nodosa, RA) or arterial occlusion (diabetes) results in what type of nerve pathology?
Vascular - will see neuropathy in multiple distributions
Diabetes, chemotherapy agents, and lead poisoning resulting in sensory > motor deficits results in what type of nerve pathology?
Axonal polyneuropathies
What type of disease presents with symmetric neuropathy with distal sensory loss in feet, loss of thermal/ vibratory sense first +/- “pain”?
Diabetes (polyneuropathy)
What type of nerve pathology is a/w the absence of sensory involvement, and the involvement of proximal and distal muscles and fasiculations?
Neuronal polyneuropathies- degeneration of motor neurons
What is the most common disease a/w neuronal polyneuropathies?
ALS
Guillaine-Barre and Charcot-Marie-Tooth are examples of what type of nerve pathology?
Demyelinating polyneuropathies
(usually autoimmune or inherited)
Guillain-Barre and Charcot-Marie-Tooth are examples of demyelinating polyneuropathies. Which is acute vs chronic and what might be elevated in CSF of these pts?
Guillain-Barre- acute
Charcot-Marie-Tooth- chronic
Elevated protein in CSF (all demyelinating polyneuropathies)
Pt presents with pins and needles in their feet and weakness in their legs that is moving proximally. PE shows absent DTRs in LEs. What are you concerned for and what might be of importance in pt hx?
Guillian-Barre (demyelinating, acquired)
Hx of infection- Campylobacter jejuni
Pt presents with slowly evolving footdrop and hx of frequent ankle sprains. PE shows distal wasting of intrinsic muscles of feet. What are you concerned for?
Charcot-Marie-Tooth (demyelinating, inherited)
How is chronicity of neuropathies defined?
Acute- days (trauma w/ compression/ cutting of nerve)
Subacute- 2-4 wks
Chronic- > 1 month (DM)
Most causes of peripheral neuropathy affect what?
BOTH motor and sensory
Pt presenting with sxs of weakness, fatigue, cramps, and muscle twitches is more indicative of motor or sensory injury?
Motor
Pt presenting with sxs of numbness, pain, altered sensation, or loss of coordination (least common) is more indicative of motor or sensory injury?
Sensory
Signs of focal weakness, fatigue or cramps with ROM exercises, and fasiculations are more indicative of motor or sensory injury?
Motor
Signs of loss of sharp/ dull touch, ataxia (disequilibrium), and hyporeflexia are more indicative of motor or sensory injury?
Sensory
What type of nerve pathology produces impared cutaneous sensation in a segmental pattern and may present as neck/ back pain that radiates to the extremities?
Radiculopathy- nerve root lesion
What is defined as inflammation/ degeneration of skeletal muscle?
Myopathy
How can you differentiate between myopathy and neuropathy?
Myopathy- proximal motor weakness
Neuropathy, distal motor weakness, sensory loss, loss of reflexes
What condition typically produces sxs of upper and/ or lower motor neuron dysfunction WITHOUT sensory sxs?
Motor neuron diseases
(peripheral neuropathy)
What condition usually presents with symmetrical distal sensory involvement and symmetrical proximal motor involvement?
B12 deficiency
(peripheral neuropathy)
What diagnostic studies are ordered if suspicion for neuropathy?
NCS, EMG
Interpretation of NCS/ EMG shows slowing of the nerve conduction velocity. What type of neuropathy are you concerned for?
Demyelinating neuropathy
Interpretation of EMG shows denervation changes. What type of neuropathy are you concerned for?
Axonal neuropathy
Interpretation of NCS/ EMG shows slowing of a segment of one nerve. What type of neuropathy are you concerned for?
Mononeuropathy
Interpretation of NCS/ EMG shows slowing of nerve conduction velocity on multiple nerves. What type of neuropathy are you concerned for?
Polyneuropathy
In addition to NCS/ EMG, what diagnostics should be ordered if you are suspicious of an inflammatory cause?
Nerve bx
In addition to NCS/ EMG, what diagnostics should be ordered if you are suspicious of myopathy?
Muscle bx
In addition to NCS/ EMG, what diagnostics should be ordered if you are suspicious of a tumor?
Imaging
What is the pharmacologic tx for neuropathies?
NSAIDs
(others: Gabapentin, Pregabalin, TCAs, Duloxetine, Venlafaxine, Carbamazepine)
What might be included in the tx for DM for neuropathic pain?
TCAs
What pharmacologic tx is NOT effective in the tx of Guillian-Barre?
Steroids
Tx is supportive
What might be included in the tx of ALS for fasiculations?
Anticonvulsants
What is included in non-pharmacologic tx for neuropathies?
PT
TENS
Relaxation techniques
Magnets
Where does weakness start/ progress in ALS?
Starts in hands/ arms and progresses to legs
Muscle twitching/ cramps also common
Pt presents with painless, progressive weakness of intrinsic muscles of the hand, and presence of upper and lower motor neuron signs in the same limb with NO alteration in sensation. What are you concerned for?
ALS
(idiopathic)
What LMN findings might be noted on PE of a pt with ALS? (5)
Fasiculations (tongue)
Weakness
Atrophy
Muscle cramps
Hyporeflexia
What UMN findings might be noted on PE of a pt with ALS? (6)
Slow movement
Incoordination
Increased tone
Hyperreflexia (Babinski)
Spasticity
Clonus
How is ALS diagnosed?
Clinically
(NCS and imaging normal, EMG- widespread involvement of proximal and distal muscles)
What is the prognosis for ALS?
(mean duration of time between sxs and death)
27- 43 months