Neurology Flashcards
Name all cerebellar signs (DASHING)
- Dysdiadochokinesis (impaired rapidly alternating movements)
- Dysmetria (past pointing)
- Ataxia
- Slurred speech (dysarthria)
- Hypotonia
- Intention tremor
- Nystagmus
- Gait abnormality
What is CIDP?
What are the 3 symptoms you see O/E?
How do you differentiate it from GBS?
Chronic inflammatory demyelinating polyneuropathy. Tends to be symmetric sensorimotor disorder, though pure motor and pure sensory, as well as multifocal variants can occur.
- Autoimmune demyelination of peripheral nerves; clinically it resembles Guillain-Barre, causing 1) severe areflexia, 2) limb weakness, 3) proprioceptive loss. Rarely produces significant respiratory/bulbar muscle weakness.
- Crucial distinction from GBS is timing - CIDP worsens over >8 weeks (i.e. subacute) and has a slower recovery.
What is the treatment for CIDP?
Steroids and plasma exchange or IVIG.
ΔΔ of sensory ataxia:
- Spinal cord disorders affecting posterior columns: cervical spondylosis, demyelination (MS)
- Metabolic causes: B12 deficiency (malnutrition, alcoholism, Crohn’s, Coeliac Disease), copper deficiency (gastrectomy, zinc supplementation)
- CIDP
- IgM paraproteinaemic neuropathy (PPM)*
- Friedreich’s ataxia has a significant peripheral nerve component
- Nitrous oxide abuse OR nitrous oxide as analgesic during childbirth following significant emesis in pregnancy
- typically manifests neurologically as a length-dependent, axonal loss, sensorimotor polyneuropathy - can precede other clinical symptoms /diagnosis of underlying condition by years. NB: monoclonal gammopathy can occur in: multiple myeloma, MGUS, Waldenstrom’s macroglobulinemia, lymphoma.
Causes of cerebellar dysfunction: vascular.
Blockage of which vessel is most often responsible for a cerebellar infarct?
- Cerebellar haemorrhage (hx: HTN, anticoagulation/antiplatelet therapy)
- Cerebellar infarction/TIA: (hx: HTN, ischaemic heart disease, AF, diabetes, hyperlipidemia)
PICA (most common location for a cerebellar infarct) –> lateral medullary syndrome: contralateral loss of sensation, cranial nerve deficits (dysphagia, dysarthria), inferior cerebellar peduncle (–> ipsilateral cerebellar signs: ataxia, past pointing, dysdiadochokinesia), vestibular nuclei (–> vomiting, vertigo, nystagmus). Damage to hypothalamospinal fibres disrupts SNS relay and can –> Horner’s syndrome.
Other vessels: AICA, SCA.
Causes of cerebellar dysfunction: inflammatory/infectious (3 answers)
Abscess formation (HX: infection elsewhere, fever and very unwell, IVDU)
Acute cerebellitis (viral) (notably chickenpox within 3wk of presentation)
Creutzfeldt-Jakob disease (S/S: dementia, myoclonus, characteristic EEG changes)
Causes of cerebellar dysfunction: autoimmune
MS
Causes of cerebellar dysfunction: metabolic
1) Myxoedema i.e. hypothyroidism (other S/S: dry skin/hair, overweight, cold intolerance, slow-relaxing reflexes, bradycardia)
2) Hypoglycaemia
3) Alcohol (vitamin B1 deficiency)
Causes of cerebellar dysfunction: neoplastic
Paraneoplastic: subacute cerebellar degeneration
Acoustic neuroma: benign Schwann cell tumour of vestibular nerve, between the cerebellopontine angle and internal auditory meatus in the petrous bone. S/S: progressive unilateral deafness, then vertigo, then ipsilateral 5th, 6th and 9th nerve palsies (reduced corneal reflex; facial weakness - though rare, suggests severe;), and ipsilateral cerebellar signs. Later < papilloedema. D/d for acoustic neuroma is meningioma. Acoustic neuroma is associated with neurofibromatosis type II.
What passes through the internal auditory meatus?
Facial nerve
Vestibulocochlear nerve
Vestibular ganglion
Labyrinthine artery (branch of AICA)
Causes of cerebellar dysfunction: degenerative
Multi-system atrophy (MSA): atypical parkinsonism - primary autonomic failure in addition to ataxia.
Spinocerebellar ataxia (SCA) - group of hereditary ataxias caused by degeneration of the cerebellum; late-onset (>25y), usually AD.
Friedreich’s ataxia: early onset (<25y), AR. Degeneration of neurons in the spinocerebellar tracts, dorsal columns, and corticospinal tracts (due to trinucleotide repeat expansion –> defiency of frataxin, a mitochondrial protein). Multi-system disorder - also affects endocrine pancreas, causes cardiomyopathy, kyphoscoliosis and pes cavus, lower limb areflexia yet upgoing plantars. Causes early death age 30-50.
Causes of cerebellar dysfunction: drugs
Alcohol
Phenytoin
Carbamazapine
Aside from vertigo, what are the other causes of unsteadiness?
- Pre-syncope - same causes as syncope: vasovagal, cardiovascular (arrhythmia e.g. AF, ACS, IHD or valvular disease esp. aortic stenosis; PE), orthostatic hypotension
- Seizure (transient LOC rather than just unsteadiness)
- Ophthalmological: cataracts, macular degeneration, visual field defects (e.g. pituitary), eye movement disorders e.g. 4th nerve palsy causes problems going down stairs; internuclear ophthalmoplegia in MS causes complex opthalmoplegia (other causes: myaesthenia, retro-orbital mass, midbrain lesion, cavernous sinus lesion (–> painful ophthalmoplegia; palsy of nerves that pass through the CS - 3, 4, 5a and 6)
- Hyperventilation - anxiety, asthma, PE, interstitial lung disease
- Anaemia
Causes of orthostatic hypotension?
Hypovolaemia (e.g. haemorrhage such as GI bleed; vomiting/diarrhoea, excessive diuretic use)
Iatrogenic (beta-blockers, diuretics, vasodilators, antidepressants)
Autonomic failure (diabetic neuropathy, PD)
Vestibular neuronitis (/labyrinthitis): clinical features?
signs?
acute-onset severe vertigo, nausea and vomiting (often patient is prostrate as head movement exacerbates symptoms)
patient previously well, now unable to leave bed
hearing loss + vertigo = vestibular labyrinthitis
signs: nystagmus, gait ataxia, +ve Quix test (seated Romberg’s)
Tx of vestibular neuronitis?
Vestibular sedative (prochlorperazine, a D2 antagonist), but long-term recovery relies on central compensation - so short-term use of the sedative only.
If SNHL, steroids.
3 symptoms of Meniere’s disease? (endolymphatic hydrops)
- Unilateral tinnitus (+ aural fullness/pressure)
- Fluctuating unilateral SNHL
- Recurrent attacks of vertigo lasting >20 min (+/- nausea/vomiting/ autonomic effects)
Pathophys: increase in pressure/change in biochem of endolymph
Causes: idiopathic, post-traumatic (ear surgery, head injury), post-infectious
Tx: prochlorpemazine (D2 receptor antagonist; antipsychotic but also prescribed as antiemetic)
If very severe disease, consider labyrinthectomy (chemical with gentamycin, or surgical)
BPPV clinical features?
Brief (30s) attacks of vertigo provoked by rapid changes in head position, typically + nausea.
~50y onset.
Worse in morning and evening.
Bouts typically last a few weeks, then a degree of resolution.
Pathophys: otoliths become dislodged within utricle, migrate through endolyph to lie usually in the posterior semicircular canal –> sensation of vertigo
Dx: Dix-Hallpike test
Tx: Epley manouvre
Causes of cord (+/- root) compression?
Infection: epidural abscess, discitis
Tumours: extradural (i.e. in vertebrae - usually mets, or multiple myeloma); intradural/extramedullary (meningiomas, Schwannomas, neurofibromas), intramedullary (astrocytoma, ependymoma, haemangioblastoma)
Degeneration of surrounding structures: cervical spondylosis i.e. osteoarthritis of the spine
Haematoma: AVM, spontaneous (warfarin), trauma. Haematoma of any cause can be extradural, intradural or intramedulalry.
Cystic lesions: extradural, intradural (arachnoidal), intramedullary (syringomyelia)
Causes of epidural abscess?
Spinal surgery/anaesthesia
Spinal trauma
IVDU (especially if concomitant HIV+)
Septic embolus from endocarditis
Local spread e.g. from vertebral osteomyelitis, psoas abscess, contiguous soft-tissue infx e.g. boils
Other risk factors: immunosuppression (diabetes, HIV)
Usually S. aureus; if chronic can be TB
SIGNS of cord compression and what is the ONE symptom that it usually presents with?
Usually presents with WEAK LEGS
Neck: limited painful neck movement +/- crepitus; flexion may produce tingling down spine (L’hermitte’s sign)
Arms/legs:
- Motor: LMN signs @ level of compressed cord (due to simultaneous root compression), and UMN signs below - visible atrophy of hand and forearm muscles, sensory loss (especially pain & temperature), spastic weakness (e.g. clumsy hands; often one leg is more weak and spastic than the other, and patient may describe legs as HEAVY; can have foot drop), brisk reflexes, upgoing plantars.
- Sensory: reduced proprioception and vibration sense; numbness in hands.
- Autonomic: incontinence, hesitance, urgency (but NB these are often late signs)
How would you describe the pattern of weakness of weak hip flexion, weak knee flexion, but intact hip and knee extension?
Pyramidal weakness
In spastic paraplegia/quadriplegia, how are the limbs held?
Arm: shoulder adducted, with flexion at the elbow and flexion at the wrist and fingers. (flexors > extensors)
Legs: hip extended (extensors > flexors), adducted, and often externally rotated. Weakness of foot dorsiflexion and eversion –> plantar flexion (foot drop) and inversion of foot.
Tell me about FOOT DROP
Foot drop is due to a weak tibialis anterior (dorsiflexion & eversion of foot) and is usually due to LMN disease, e.g. L4-L5 radiculopathy (e.g. slipped disc), CPN neuropathy, DM, conus medullaris, CES, plexus.
CNS pathology however can also cause foot drop due to spastic weakness (pyramidal lesion) wherein foot plantarflexors>dorsiflexors –> foot drop. e.g. stroke, prolapsed disc, MS, MND
Differentials for weak legs
Questions: acute/gradual onset? unilateral foot drop? motor and/or sensory? LMN or UMN weakness? symmetrical/asymmetrical?
Unilateral foot drop: L4/L5 radiculopathy, diabetes, alcoholic neuropathy, isolated CPN palsy, mononeuritis multiplex (e.g. vasculitis) MND, stroke, MS.
Weak legs, sensation intact: MND, GBS or CIDP, parasagittal meningioma (plexus)
Chronic flaccid paraparesis: peripheral neuropathy, myopathy (rare, arms also involved)
Chronic spastic paraparesis: MS, cord tumour (astrocytoma/haemangioblastoma/ependyoma), cord mets, MND, syringomyelia
What do you know about Cauda Equina syndrome?
It’s caused by compression of the cauda equina spinal roots (L1-S5), & causes sudden-onset and rapidly progressive flaccid lower limb weakness, followed by sphincter involvement. Saddle anaesthesia (S3-S5). Also severe BACK PAIN and RADICULAR PAIN that is asymmetrical (but note CES does not always have pain associated).
Signs: absent ankle jerks.
Etiology: usually caused by a lumbar disc prolapse; other causes are spinal stenosis, malignancy, trauma (e.g. LP, or penetrating trauma), epidural abscess, epidural haematoma, cord tumour.
Muscles affected: LMN weakness of muscles supplied by lower lumbar roots and sacral roots (this is basically all leg movement except less so the muscles supplied directly from the top of the lumbosacral plexus L1-L3 i.e. psoas, or the femoral nerve i.e. L2-L4 which supplies iliacus and the quadriceps - so might see less affected hip flexion and knee extension)
Tx: decompressive laminectomy.
What are the red flags for Cauda Equina Syndrome? (4)
Severe back pain
Saddle anaesthesia
Incontinence
Sexual dysfunction
Causes of ischaemic stroke?
- Arterial thrombosis, e.g. MCA (thrombosis in situ, atherothromboembolism - most commonly from carotid plaque), cardiac embolus - AF, endocarditis, cardiac mural thrombus in MI)
- Cerebral small vessel disease (age-related, hypertension-related, or cerebral amyloid angiopathy)
Less commonly:
Hypoperfusion e.g. sepsis
Carotid artery dissection
Vertebral artery dissection (–> posterior circulation infarct)
Vasculitis
Venous sinus thrombosis (acute venous infarct)
CADASIL
Causes of intra-axial haemorrhagic stroke?
Hint: H, T, C, A, A, C
Where do they tend to affect?
Hint: B, L, P, C
Hypertension (usually deep haemorrhage - basal ganglia, internal capsule, brainstem)
Tumours (glioblastoma especially)
Cerebral amyloid angiopathy (typically superficial i.e. lobar)
AVMs
Anticoagulation/antiplatelets
Cocaine use
In general, possible sites of intra-axial haemorrhage are: basal ganglia, lobar, pontine, cerebellar.
Which type of intrcranial haemorrhage is associated with CN III palsy (fixed dilated pupil, down and out)?
Epidural haemorrhage
What are the signs and symptoms of epidural haematoma?
What investigations are needed?
What is the treatment?
Trauma, lucid interval then rapid deterioration, intense headache (due to stripping of dura from inside of skull), vomiting, confusion, can have contralateral weakness of extremities due to pyramidal tract compression
Signs: contralateral visual field loss (due to compression of PCA ipsilateral to lesion), CN III palsy (surgical)
Investigations: CT/MRI diagnoses (convex)
Tx: emergency evacuation
What most often causes a subdural haematoma?
Is it an acute or chronic presentation?
Pathology: tears in bridging veins crossing the subdural space, between the dura mater and arachnoid mater
Causes:
- Major head trauma usually in younger adults e.g. falls, violence, motor vehicle accident. Patients are often rendered comatose at time of injury, a subset of patients remain conscious and get raised ICP symptoms (sudden severe headache, vomiting/nausea), whilst another subset deteriorates as the haematoma expands.
- Minor trauma e.g. a fall without head hit, in the elderly - weeks to months before it becomes clinically evident, as re-bleeding –> expansion of haematoma. Most commonly presents with altered mental state (confusion, drowsiness, coma).
+/- focal neurological deficits in 50% of patients due to direct pressure on the cerebral hemispheres, mild limb weakness, headache.
What are the risk factors for SDH?
Very young or very old age, alcohol abuse, dementia, anticoagulated, CSF leak.
What S/S would you expect with an SDH?
Working age: headache, nausea/vomiting, Hx of trauma to head
Elderly: Gradually increasing headache and worsening confusion, gait dysfunction
Differential diagnosis of myelopathy? i.e. if it’s NOT cord compression.
Hint: T M A V G S M S
vascular (x2)
inflammatory (x4)
degenerative
misc (begins with S)
Transverse myelitis
MS
Anterior spinal artery occlusion (from e.g. acute disc herniation, cervical spondylosis, neoplasia, occlusion to Artery of Adamkiewicz, or more commonly aortic aneurysm or dissection)
Cord vasculitis (PAN, syphilis)
Guillain-Barre (though LMN signs)
Stroke
MND (asymmetric onset of weakness in leg or arm is the AML presentation, e.g. foot drop or hand weakness; however can present for example as a spastic tetraparesis)
Syringomyelia
Causes of subarachnoid haemorrhage?
Head trauma
Non-traumatic: berry aneurysm in circle of Willis, AVM.
Symptoms of SAH?
Thunderclap headache develops over seconds-mins, often occipital
Vomiting/nausea
Collapse, seizures (more common in aneurysmal cause), and confusion/coma often follow
Neck stiffness ~6h after initial onset
If origin is posterior communicating artery, can cause a IIIrd nerve palsy (surgical)
6th nerve palsy is non-specific for raised ICP
What is meant by surgical vs. medical 3rd nerve palsy?
Compression of III along its course by aneurysm-> both the parasympathetic fibres (that supply the ciliary bodies and the sphincter pupillae) and somatic fibres are affected, with parasympathetic fibres affected first, causing fixed dilated pupil –> down+out & ptosis. Usually aneurysm is posterior com. artery, PCA, or SCA. Another cause of surgical third nerve palsy is a subarachnoid haemorrhage originating from one of these aneurysms!!!
And lastly, epidural haematoma can –> tentorial herniation, causing a surgical III palsy.
Whereas ischaemic causes (microvascular disease, e.g. diabetes, hypertension, hyperlipidemia) SPARE the pupil because it affects the vasoneurium covering the nerve, therefore the inner part of the nerve (somatic fibres) are affected more.
Summary: trauma (aneurysm or epidural haematoma) –> fixed dilated pupil +/- plegia and ptosis.
Differential diagnosis for a 3rd nerve palsy:
Nuclear lesions: stroke affecting midbrain, demyelination, abscess, tumour, midbrain herniation.
Subarachnoid lesion: aneurysm, SAH, meningitis, inflammation including vasculitides (giving rise to mononeuritis multiplex)
Cavernous sinus lesion: tumour (pituitary, craniopharyngioma), thrombosis, aneurysm, fistula, infection, inflammatory
Orbital lesion: trauma, tumour
Small vessel disease: diabetes, HTN, atheroscleroris
Infection: Lyme disease, syphilis, basilar meningitis
How do you manage a suspected SAH?
CT head
If CT negative, delayed LP (12hr after symptom onset) (+ measure opening pressure) to detect xanthochromia.
If CT or LP is positive, –> CT angio or digital subtraction angiography.
Stabilisation: if depressed consciousness may need mechanical ventilation or intubation.
Vasospasm prevention: IV fluids (saline), nimodipine (Ca2+ antagonist).
Surgical management: endovascular coiling if aneurysm; may need craniotomy/burr holes to evacuate haematoma
Other: analgesia (IV opiates if necessary), anti-emetics, elevate head 45deg, re-examine CNS often (BP, pupils, GCS)
Complications of SAH: vasospasm, hydrocephalus, re-bleed. Repeat CT if deterioration occurs.
How might a dural venous sinus thrombosis present?
S/S are gradual (often weeks/months progression) due to slow growth of the thrombus. HEADACHE is presenting symptom in 80% of cases. Focal deficits (e.g. hemiparesis, hemisensory disturbance, SEIZURES (often followed by a Todd's paresis), >>GCS, papilloedema. - a focal deficit occurs in 50% of cases.
Venous thrombosis is an important differential for benign intracranial hypertension - they present similarly.
Rare but classical clinical pictures are superior sag sinus thrombosis with bilateral or alternating deficits +/- seizures, and cavernous sinus thrombosis with chemosis, proptosis, and painful ophthalmoplegia.
Thrombosis in the superior sagittal or transverse sinus can affect reabsorption of CSF –> hydrocephalus.
Causes of venous sinus thrombosis?
Infective (typically affect cavernous sinus; S/S would be diplopia, sharp pain behind/around eyes, 3rd nerve palsy progressing to also include 4th and 6th, V1 and V2)
Non-infective: systemic inflammatory/granulomatous conditions, malignancy, oral contraceptive pill, hereditary prothrombotic conditions e.g. factor V Leiden, pregnancy.
Causes of acute hydrocephalus?
Vascular: cerebellar haemorrhage/infarction, SAH
Infection: acute meningitis
Trauma
Neoplasm: posterior fossa tumour, ependymoma of 4th ventricle
Misc: colloid cyst of 3rd ventricle
Signs of acute hydrocephalus?
Raised ICP signs: headache, vomiting, diplopia due to 6th nerve palsy, reduced upgaze, impaired level of consciousness.
Signs of chronic hydrocephalus?
Gait disturbance, memory disturbance or dementia, urinary incontinence, raised ICP symptoms
Causes of chronic hydrocephalus?
Following SAH
Chronic meningitis
Slow-growing posterior fossa tumour
Idiopathic (1/3)
How does MND present? (AML, progressive bulbar palsy, progressive muscular atrophy)
AML: asymmetrical onset of weakness in the leg or arm (e.g. foot drop or hand weakness), or can also present with dysarthria or dysphagia. Weakness of head flexion can cause dropped head.
Signs: variable mixture of UMN signs and LMN signs in the limbs, head and neck. Wasting, fasiculations, brisk reflexes and upgoing plantars. Corticobulbar signs, e.g. brisk jaw jerk. Occasionally patients with MND have sensory symptoms, but NO SIGNS.
Progressive bulbar palsy: palsy of the facial muscles, tongue, muscles of mastication, and muscles of swallowing (due to loss of motor nuclei function in the medulla) –> presents with dysarthria and/or dysphagia. Limb involvement occurs LATER (perhaps years). Signs are of a LMN lesion: flaccid weakness, fasciculations of tongue , normal/absent(!) jaw jerk. Speech is quiet, hoarse, nasal.
Progressive muscular atrophy: LMN weakness of distal muscles > proximal. Often begins asymmetrically in the small muscles of the hands or feet, then spreads. Associated with LMN signs: wasting, weakness, fasciculations - however, tendon reflexes are usually preserved. Often progresses to include UMN signs with time. Most develop bulbar symptoms. Better prognosis than ALS (5-10y).
Think of MND in a >40y old (mean age of presentation though is 60) with stumbling (spastic gait, foot drop), weak grip (door handles, turning keys), or aspiration pneumonia.
Frontotemporal dementia in 25%.
No sensory loss or sphincter disturbance (distinguishes MND from MS and polyneuropathies)
MND NEVER affects external eye movements (III, IV, VI) distinguishing it from myaesthenia.
How is MND diagnosed?
Diagnosis strongly supported by PROGRESSIVE LMN and UMN signs and most importantly weakness, with involvement of >3 limbs, or a limb and bulbar muscles.
MRI to exclude structural causes.
LP to exclude inflammatory cause.
Neurophysiology studies.
Mimics of MND?
Spondylotic myeloradiculopathy (cervical and lumbar)
Multifocal motor neuropathy (MMN; purely affects motor neurons - LMN without any UMN signs, no sensory deficits, and conduction block demonstrated in neurophysiology - often misdiagnosed as ALS, and other similar conditions are CIDP or vasculitic polyneuropathy).
Charcot-Marie-Tooth presents similarly to the progressive muscular atrophy variant of MND (distal weakness and wasting, though hyporeflexia rather than normal reflexes -however CMT usually presents in adolescence. Pathology of CMT is demyelination and remyelination of the peripheral nerves. Motor predominance.
Syringomyelia: burning/tingling pain in cape distribution (neck and shoulders), +/- numbness or decreased temperature sensation; progressive weakness and wasting in the hands and arms, and eventually shoulders. Pathology is compression of the spinothalamic and corticospinal tracts. Sparing of dorsal columns.
Myaesthenia Gravis: muscle weakness and fatiguability, particularly of the proximal limbs, ocular muscles (–> ptosis, diplopia from complex ophthalmoplegia), and bulbar muscles (weakness of face and jaw muscles, dysarthria, dysphonia, dysphagia). Neck flexion/extension weakness can –> head drop. Respiratory muscle weakness can cause SOB. Reflexes are normal or hyper-reflexic but they fatigue. Sensory examination is normal.
CIDP
Causes of complex ophthalmoplegia?
Myaesthenia (eye movements are fatigable, and there are no pupillary signs)
MS (usually other brainstem signs/symptoms accompany)
Thyroid eye disease (there will typically be proptosis and not ptosis, chemosis, lid lag) - due to soft-tissue inflammation and swelling within the orbit causing restriction of eye movements.
Oculopharyngeal dystrophy (occurs in 60-70 year olds, with progressive ptosis and ophthalmoplegia without pupillary changes, and –> to dysphagia and facial weakness)
Cavernous sinus syndrome (painful ophthalmoplegia affecting one or usually more of 3, 4, and 6)
What structures are contained within the cavernous sinus?
Internal carotid artery
Sympathetic carotid plexus
Cranial nerves III, IV, VI and V1 and V2
Signs of cavernous sinus syndrome?
Painful ophthalmoplegia (unilateral single or usually combined nerve III, IV and VI palsies)
Horner’s syndrome - because of this the pupil may be mid-position and fixed with both parasympathetic and sympathetic disruption
Anaesthesia of forehead, maxilla and conjunctive (V1 and V2)
Proptosis
Chemosis
Papilloedema +/- visual loss
Causes of cavernous sinus syndrome?
Vascular: cavernous sinus aneurysms or fistulae, thrombosis (usually complicating infection of the ethmoid, frontal and sphenoid sinuses or extension of dental or orbital infx)
Inflammatory: herpes zoster, sarcoid, Wegener’s granulomatosis
Idiopathic: Tolosa-Hunt syndrome
Neoplasm: meningioma, extension of pituitary tumour, metastatic disease
Symptoms of carpal tunnel syndrome and which nerve does it involve?
Median nerve (C6-T1)
Aching pain, numbness, paraesthesia in the sensory distribution of the median nerve (lateral digits i.e. thumb, index and middle finger), especially at night, that is relieved by dangling the hand and shaking it.
Palm is often spared (palmar cutaneous branch of the median nerve branches off proximally to the carpal tunnel). In advanced CTS there may be weakness of thumb abduction and thenar eminence wasting (both due to denervation atrophy of abductor pollicis brevis)
Signs: reproduction of symptoms by percussing over the median nerve (Tinel’s test) or holding the wrist in full flexion for one minute (Phalen’s test), though both are quite non-specific.
Pope’s hand (hand of benediction) when patient is asked to make a fist, due to inability to flex the index and middle fingers at the PIPs (this is because the median nerve supplies the lateral aspect of flexor digitorum profundus FDP, which flexes the 2nd and 3rd digits)
Ape hand - inability to abduct thumb, so with the hand at rest the thumb is held close to the palm.
Risk factors for carpal tunnel?
Female to male ratio of 5/1, peak incidence 45-60y, pregnancy, diabetes, RA, obesity, hypothyroidism, acromegaly, prev injury to wrist, repetitive hand/wrist movements.
MEDIAN TRAP Myxoedema Enforced flexion Diabetic neuropathy Idiopathic Acromegaly Neoplasms (e.g. myeloma) Benign tumours (lipoma) Rheumatoid arthritis Amyloidosis Pregnancy
Differential diagnosis for carpal tunnel syndrome?
C6 radiculopathy (likely to also have neck pain or symptoms involving the entire arm length)
Pronator teres syndrome (median nerve compression by pronator teres - symptoms will extend to the proximal forearm, and palm will also be numb.
What causes an ulnar nerve palsy? (C7-T1)
Chronic compression/entrapment, either within the cubital tunnel at the elbow, or more distally in the forearm where the ulnar nerve passes between the two heads of flexor carpi ulnaris (FCU).
Or laceration/trauma at the wrist or elbow (e.g. elbow fracture)
Symptoms of ulnar nerve palsy?
Lack of hand grip
Painful paraesthesia and numbness of ring finger/little finger and ulnar border of palm
Signs:
Weakness and/or wasting of flexor carpi ulnaris (FCU), flexor digitorum profundus (FDP), interossei (so –> unable to cross fingers in ‘good luck’ sign) and third and fourth lumbricals (lumbricals flex the MCP joints and extend the interphalangeal joints, so in ulnar palsy the opposite happens and a claw hand is produced, due to inability to extend the fingers at the interphalangeal joints –> permanent flexion).
With lesions at the wrist, claw hand is more marked, because FDP is proximal to the lesion therefore still intact.
Radial nerve palsy (C5-T1) is caused by?
Site of damage is usually where the nerve runs down the posterior aspect of the humerus in the spiral groove. Palsy is usually from mid-shaft fracture of the humerus, or sleeping in a strange position (‘Saturday night palsy’)
What does the radial nerve supply?
Radial nerve supplies the posterior compartment of the forearm: WRIST EXTENSORS and MCP joint EXTENSORS, as well as supinator, extensor pollicis brevis & longus (thumb extension), and abductor pollicis longus (thumb abduction; this is also done by abductor pollicis brevis, which is supplied by the median nerve).
Also the radial nerve supplies bradioradialis (elbow flexion) and triceps brachii (elbow extension)
Symptoms of radial nerve palsy?
Wrist drop
Weakness of finger extension and thumb extension
Sensory loss at dorsum of hand and forearm
Posterolateral elbow pain similar to tennis elbow
What does the common peroneal nerve supply and what are its branches?
Branch of the sciatic nerve, arising in the popliteal fossa and dividing into the superficial and deep fibular nerves.
Sensory innervation to upper 2/3 of lateral and posterior calf + dorsum of foot, via the superfical branch.
CPN before its division innervates biceps femoris (one of the hamstrings; NB rectus femoris is one of the quadriceps). The deep fibular nerve innervates the anterior compartment of the calf: tibialis anterior (ankle dorsiflexion and eversion), extensor hallucis longus (big toe extension), extensor digitorum longus (toe extension, ankle dorsiflexion), peroneus tertius (ankle dorsiflexion and eversion)
Presentation of CPN palsy?
Foot drop
Sensory loss/tingling to upper 2/3 of lateral and posterior calf and dorsum of foot
What innervates the foot plantarflexors?
The POSTERIOR COMPARTMENT of the calf is innervated by the tibial nerve (S1-2), a branch of the sciatic nerve.
This includes … the toe flexors, ankle plantarflexors (tibialis posterior, gastrocnemius, soleus), ankle invertors.