22. Numbness/paraesthesia/tingling Flashcards
History taking sensory disturbance?
Examination sensory disturbance?
Patterns of sensory loss
Single area of altered sensation
Multiple distal areas affected symmetrically
Multiple distal areas affected asymmetrically
Spinal symptoms
Hemisensory
Intermittent
Ischaemic symptoms
Functional
ddx SD single area of altered sensation
mononeuropathies such as carpal tunnel, cubital tunnel, meralgia parasthetica.
Radiculopathy such as cervical radicluopathy, sciatica, cauda equina, foot drop, shingles, lyme disease
ddx multiple distal areas affected symmetrically
predominant sensory loss: ABCDE - alcohol, b12 deficiency, cancer and CKD, diabetes and drugs, every vasculitis.
Motor loss: GBS, CIDP, charcot marie tooth, lead posioning,
ddx multiple distal areas affected asymmetrically
Mononuritis multiplex
WARDS PLC
Wegeners
Aids/Amyloid
Rheuamtoid
Diabetes
Sarcoidosis
Polyarteritis nodosa
Leprosy
Cancer
ddx spinal eg symmetrical, sensory level, signs mixed, sphincter involvement
degenertaive cervical myelopathy, lumbar spinal stenosis, neoplastic spinal cord compression, brown-sequard, subacute combined degeneration, friedrichs ataxia, syringomyelia,
ddx hemisensory loss
stroke, MS, parietal lobe tumour
ddx intermittent sensory loss
hyperventilation, migraine, TIA, parietal lobe epilepsy, peripheral arterial disease
ddx functional sensory loss
conversion disorder
Axillary nerve normal function
Motor: Shoulder abduction (deltoid muscle)
Sensory to inferior region of the deltoid muscle
How may the axilliary nerve become damaged?
Humerus surgical neck fracture: usually by direct blow or falling on an outstretched hand
Examination axillary nerve damage
flattened deltoid, loss of sensation over deltoid
weakness of shoulder abduction
Normal function of radial nerve
Motor: “stop”
Extension of wrist, fingers, forearm, thumb
Sensory: area between the dorsal aspect of the 1st and 2nd metacarpals
How may the radial nerve become damaged?
humeral midshaft fracture
How would a damaged radial nerve present?
wrist drop
due to unopposed flexion of the wrist
weakness of thumb extension
Normal function of median nerve
“power to the people”
Motor: LOAF muscles
Lateral lumbicals
Opponens pollicis
Abductor policis
Flexor policis brevis
wrist flexion, finger flexion, thumb opposition, pronation
Sensation : Palmar aspect of lateral 3½ fingers
How does the median nerve become damaged
compression at the wrist (carpal tunnel syndrome)
how would a damaged median nerve present?
weakness of thumb abduction (abductor pollicis brevis)
wasting of thenar eminence (NOT hypothenar)
Tinel’s sign: tapping causes paraesthesia
Phalen’s sign: flexion of wrist causes symptoms
sign of benediction
Anterior interosseous nerve: opposition of the thumb and index finger* ‘okay sign’
Normal function of ulnar nerve?
“peace sign”
motor: abduction of fingers
Sensory: medial 1 1/2 fingers
adduction of thumb (adductor policis)
How would the ulnar nerve become damaged?
medial epicondyle fracture
How would a damaged ulnar nerve present?
frommets sign (cant adduct thumb properly)
inability to abduct/adduct fingers and adduct thumb
sensory loss over medial 1 1/2 fingers
cubital tunnel syndrome
Tingling and numbness of the 4th and 5th finger which starts off intermittent and then becomes constant.
Over time patients may also develop weakness and muscle wasting
Pain worse on leaning on the affected elbow
Medial epicondyle fracture -
Damage may result in a ‘claw hand’
Normal function of long thoracic nerve
innervation of serratus anterior
- protraction of the scapula
- external rotation
How would long thoracic nerve become damaged?
Often during sport e.g. following a blow to the ribs. Also possible complication of mastectomy
how does damage to long thoracic nerve present?
winged scapula
normal function of the lateral cutaneous nerve
no motor
sensation: Lateral and posterior surfaces of the thigh
how would the lateral femoral cutaneous nerve become damaged?
As the nerve curves medially and inferiorly around the anterior superior iliac spine (ASIS), it may be subject to repetitive trauma or pressure. (meralgia paraesthetica)
Risk factors:
Obesity
Pregnancy
Tense ascites
Trauma
Iatrogenic, such as pelvic osteotomy, spinal surgeries, laparoscopic hernia repair and bariatric surgery. In some cases, may result from abduction splints used in the management of Perthe’s disease.
Various sports have been implicated, including gymnastics, football, bodybuilding and strenuous exercise.
Some cases are idiopathic.
How would a damaged lateral cutaneous nerve pressent?
Lateral and posterior surfaces of the thigh
Burning, tingling, coldness, or shooting pain
Numbness
Deep muscle ache
Symptoms may be reproduced by deep palpation just below the ASIS (pelvic compression) and also by extension of the hip.
There is altered sensation over the upper lateral aspect of the thigh.
There is no motor weakness.
Symptoms are usually aggravated by standing, and relieved by sitting
They can be mild and resolve spontaneously or may severely restrict the patient for many years.
meralgia paraesthetica
Injection of the nerve with local anaesthetic will abolish the pain. Using ultrasound is effective both for diagnosis and guiding injection therapy in meralgia paraesthetica
Nerve conduction studies may be useful.
What does the common peroneal nerve do?
Motor:
Foot dorsiflexion and eversion
Extensor hallucis longus
sensation: Dorsum of the foot and the lower lateral part of the leg
How does the common peroneal nerve become damaged?
This is often secondary to compression at the neck of the fibula
- Tightly applied lower limb plaster cast
- Leg crossing, squatting or kneeling
- Recent weight loss
- Baker’s cysts
Presentation of common peroneal nerve mononeuropathy
foot drop
unilateral (Bilateral foot drop is more likely to be due to peripheral neuropathy)
no weakness of hip abduction (weakness of hip abduction is a KEY sign of L5 radiculopathy)
Causes carpal tunnel
idiopathic
pregnancy
oedema e.g. heart failure
lunate fracture
rheumatoid arthritis
management carpal tunnel
NICE Clinical Knowledge Summaries currently recommends a 6-week trial of conservative treatments if the symptoms are mild-moderate
- corticosteroid injection
- wrist splints at night
if there are severe symptoms or symptoms persist with conservative management:
- surgical decompression (flexor retinaculum division)
what invetsigation might you do for ?mononeuropathy
nerve conduction studies
management cubital tunnel
Avoid aggravating activity
Physiotherapy
Steroid injections
Surgery in resistant cases
what is radiculopathy?
Nerve root compression
99% patients have radiating limb pain, often in the pattern of the dermatome, sharp/shooting in character,
with only a small proportion (about 5%) having associated neurologic symptoms such as dermatomal sensory loss, and even less commonly myotomal muscle weakness.
The two nerve roots usually affected for the upper limb are C6 and C7. The two nerve roots usually affected for the lower limb are L5 and S1.
Causes of radiculopathy
Spinal degenerative changes
Prolapsed disc (When a spinal disc becomes herniated in the neck, it can leak out into the spinal canal or nerve root tunnel and impinge on the exiting nerve root.)
Presentation cervical radiculopathy
PC: pain in the neck with radiation down the shoulder and arm in a dermatomal distribution. Unilateral dermatomal numbness or tingling (C5–C7 levels are most commonly affected). Motor symptoms, although less common, are also usually unilateral and in a myotomal distribution.
HoPC: A more generalised non-dermatomal arm ache, occipital headache, or inter-scapular pain are other common presentations.
Positive spurling test
plan ?cervical radiculopathy
Plan:
Management
1. Rule out all red flags, if any red flags: refer immediately
2. If present for <4-6 weeks and no objective neurological signs: treat conservatively for 4-6 weeks
+Reassurance
+Encourage activity and home exercise
+Analgesia: ibuprofen, paracetamol, codeine
+Consider amitriptyline, duloxetine, pregabalin or gabapentin
+Consider a referral for physiotherapy
- If present for more than 4-6 weeks OR there are objective neurological signs
Refer to confirm diagnosis with MRI and to consider invasive procedures, such as interlaminar cervical epidural injections, transforaminal injections, or spinal surgery.
What is cervical spondylosis? presentation?
Cervical spondylosis is a term used to describe degeneration of the vertebral column in the cervical (neck) region. It is otherwise known as cervical osteoarthritis. It most commonly presents in clinical practice as neck pain.
PC: Pain and/or stiffness in cervical region
Referred pain: retro-orbital, temporal, occipital, interscapular, upper limbs.
Reduced range of movement of neck (in all directions)
Poorly localised tenderness
Signs of radiculopathy (most commonly affecting nerve roots C5 to C7)
Unilateral neck, shoulder or arm pain, paraesthesia, or hyperaesthesia
Diminished arm reflexes (triceps: C7, biceps: C5/C6, supinator: C5/C6).
A small number (<0.1% of patients with cervical spondylosis) of patients with associated acute myelopathy can develop quadriplegia.
Complications: cervical radiculopathy and myelopathy
what nerve roots commonly cause cervical radiculopathy
C6/7
What nerve roots commonly cause sciatica
L5/S1
what special test is useful for diagnosing sciatica
straight leg raise
abdominal pain and a motor periperal neuropathy
Lead poisoning
Ask about blue lines on gum margin
Management of uncontrolled sciatica/sciatica not responded to conservative management
if symptoms persist e.g. after 4-6 weeks) then referral for consideration of MRI is appropriate
most common cause of sciatica
A prolapsed lumbar disc at L5/S1
features of back/leg pain in prolapsed disc
leg pain usually worse than back
pain often worse when sitting
what is mononeuritis multiplex?
Multiple areas of sensory loss in an asymmetric pattern suggest a patchy process affecting peripheral nerves such as inflammatory neuropathy or vasculitis. The term mononeuritis multiplex—meaning ‘inflammation of multiple single nerves’—is used to describe this pattern of asymmetric sensory loss.
what things should you ask about to investigate vasculitis as the cause of mononeuritis multiplex
ENT - sinusitis? epistaxis?
Respiratory - cough? SOB?, haemoptysis
Skin - purpura? mottled looking skin? tender nodules?
Neuro - mononeuritis multiplex?
Renal - haematuria, anuria?
other - heart problems?
which vasculidities may present with mononeuritis multiplex?
microscopic polyangitis
granulomatosis with polyangitis (wegners)
polyarteritis nodosa
features microscopic polyangitis? autoantibody?
ENT - none
Resp - alveolar haemorrhage
Skin - purpura
Neuro - mononeuritis multiplex
Renal - glomerulonephritis
p-ANCA
features granulomatosis with polyangitis
ENT - saddle nose, epistaxis
Resp - SOB, haemoptysis
Skin
Neuro - mononeuritis multiplex
Renal - glomerulonephritis
c-ANCA positive in 90%
features polyarteritis nodosa
ENT
Resp
Skin - livedo reticularis (mottled looking skin), tender skin nodules
Neuro - mononeuritis multiplex
Renal - haematuria, renal fialure
Other - HTN, CVS events, associated with hep B
link between anxiety and sensory disturbance
Hyperventilation (e.g. in panic attacks and anxiety states) may cause tingling in lips, fingers and toes which can present in a similar way to a polyneuropathy but the paraesthesia is transient with no permanent neurological deficit.
paraesthesia that seems to move around?
migraine
parietal lobe epilepsy
The onset of migraine can cause an aura of altered sensation that starts in one area and slowly spreads to other areas. A typical presentation is paraesthesia or tingling occurring in the face, which over 15 minutes spreads to the arm and 15 minutes later has spread down the leg. The sensory disturbance of migraine usually consists of positive phenomenology (i.e. buzzing and tingling) as opposed to loss of sensation or numbness. The presence of visual aura, photophobia and headache enable a confident diagnosis but it is important to remember that migrainous phenomena can occur without headache.
recurrent sensory symptoms in different parts of the body, each lasting more than a day could indicate
multiple sclerosis
paraestheia in the leg, need to consider?
ischaemia
what positive features suggest functional sensory loss
non-dermatomal
inconsistent on repeat examination
sharp delineation between normal and abnormal sensation at the midline or at the proximal end of a limb