Neurology Flashcards
(159 cards)
1
Q
Name all cerebellar signs (DASHING)
A
- Dysdiadochokinesis (impaired rapidly alternating movements)
- Dysmetria (past pointing)
- Ataxia
- Slurred speech (dysarthria)
- Hypotonia
- Intention tremor
- Nystagmus
- Gait abnormality
2
Q
What is CIDP?
What are the 3 symptoms you see O/E?
How do you differentiate it from GBS?
A
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.
3
Q
What is the treatment for CIDP?
A
Steroids and plasma exchange or IVIG.
4
Q
ΔΔ of sensory ataxia:
A
- 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.
5
Q
Causes of cerebellar dysfunction: vascular.
Blockage of which vessel is most often responsible for a cerebellar infarct?
A
- 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.
6
Q
Causes of cerebellar dysfunction: inflammatory/infectious (3 answers)
A
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)
7
Q
Causes of cerebellar dysfunction: autoimmune
A
MS
8
Q
Causes of cerebellar dysfunction: metabolic
A
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)
9
Q
Causes of cerebellar dysfunction: neoplastic
A
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.
10
Q
What passes through the internal auditory meatus?
A
Facial nerve
Vestibulocochlear nerve
Vestibular ganglion
Labyrinthine artery (branch of AICA)
11
Q
Causes of cerebellar dysfunction: degenerative
A
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.
12
Q
Causes of cerebellar dysfunction: drugs
A
Alcohol
Phenytoin
Carbamazapine
13
Q
Aside from vertigo, what are the other causes of unsteadiness?
A
- 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
14
Q
Causes of orthostatic hypotension?
A
Hypovolaemia (e.g. haemorrhage such as GI bleed; vomiting/diarrhoea, excessive diuretic use)
Iatrogenic (beta-blockers, diuretics, vasodilators, antidepressants)
Autonomic failure (diabetic neuropathy, PD)
15
Q
Vestibular neuronitis (/labyrinthitis): clinical features?
signs?
A
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)
16
Q
Tx of vestibular neuronitis?
A
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.
17
Q
3 symptoms of Meniere’s disease? (endolymphatic hydrops)
A
- 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)
18
Q
BPPV clinical features?
A
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
19
Q
Causes of cord (+/- root) compression?
A
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)
20
Q
Causes of epidural abscess?
A
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
21
Q
SIGNS of cord compression and what is the ONE symptom that it usually presents with?
A
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)
22
Q
How would you describe the pattern of weakness of weak hip flexion, weak knee flexion, but intact hip and knee extension?
A
Pyramidal weakness
23
Q
In spastic paraplegia/quadriplegia, how are the limbs held?
A
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.
24
Q
Tell me about FOOT DROP
A
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
25
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
26
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.
27
What are the red flags for Cauda Equina Syndrome? (4)
Severe back pain
Saddle anaesthesia
Incontinence
Sexual dysfunction
28
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
29
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.
30
Which type of intrcranial haemorrhage is associated with CN III palsy (fixed dilated pupil, down and out)?
Epidural haemorrhage
31
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
32
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.
33
What are the risk factors for SDH?
Very young or very old age, alcohol abuse, dementia, anticoagulated, CSF leak.
34
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
35
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
36
Causes of subarachnoid haemorrhage?
Head trauma
| Non-traumatic: berry aneurysm in circle of Willis, AVM.
37
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
38
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
39
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.
40
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.
41
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.
42
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
43
Signs of acute hydrocephalus?
Raised ICP signs: headache, vomiting, diplopia due to 6th nerve palsy, reduced upgaze, impaired level of consciousness.
44
Signs of chronic hydrocephalus?
Gait disturbance, memory disturbance or dementia, urinary incontinence, raised ICP symptoms
45
Causes of chronic hydrocephalus?
Following SAH
Chronic meningitis
Slow-growing posterior fossa tumour
Idiopathic (1/3)
46
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.
47
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.
48
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
49
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)
50
What structures are contained within the cavernous sinus?
Internal carotid artery
Sympathetic carotid plexus
Cranial nerves III, IV, VI and V1 and V2
51
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
52
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
53
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.
54
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
```
55
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.
56
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)
57
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.
58
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')
59
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)
60
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
61
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)
62
Presentation of CPN palsy?
Foot drop
| Sensory loss/tingling to upper 2/3 of lateral and posterior calf and dorsum of foot
63
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.
64
What causes Meralgia paraesthetica and what is it?
Palsy of the lateral cutaneous nerve of the thigh, a nerve of the lumbar plexus that emerges from the lateral border of psoas and innervates the skin of the anterolateral thigh. Entrapment of the nerve can occur under the inguinal ligament near the ASIS.
Meralgia paraesthetica = parasthesia/burning sensation and partial numbness in a patch of the skin on the anterolateral aspect of the thigh - contact of clothes is unpleasant. No motor symptoms as this nerve is purely sensory.
65
Common causes of polyneuropathy?
Diabetes or other systemic diseases, e.g. thyroid disease, paraproteinaemia, lymphoproliferative syndromes, drugs, critical illness, B12/folate deficiency.
66
How do symptoms differ in polyneuropathy caused by axonal degeneration as compared to demyelination?
In axonal degeneration (diabetes, alcohol, uremia), pattern is DISTAL e.g. stocking sensory loss. Both myelinated sensory fibres (vibration/proprioception) and unmyelinated sensory fibres (pain,temp) are lost equally. Distal muscles are weak and wasted due to denervation. Note that diabetic and alcoholic neuropathy is typically painful.
vs. in demyelinating polyneuropathies (CIDP, MMD, CMT, Guillain-Barre), where the PROXIMAL portions of nerves are often more affected, incl nerve roots - so that proximal AND distal muscles may be weak. Weakness is much more severe than in axonal degeneration, and less pronounced muscle wasting because the axons remain in continuity with the muscle. Proprioception/vibration sense markedly impaired, whilst temp/pain left intact as these aren't myelinated.
67
Symptoms of diabetic neuropathy (symmetric sensory polyneuropathy)?
- Glove & stocking numbness, tingling, and nocturnal pain
- Loss of proprioception in distal joints --> sensory ataxia and pseudoathetosis
- Weakness is end-stage: distal weakness and wasting (especially visible at hypothenar eminence, first dorsal interosseous, quadriceps, tibialis anterior)
- NB: long before weakness due to neuropathy, it manifests as skin changes due to the loss of nerve supply - swollen, hairless, dry legs.
68
What is Guillain-Barre syndrome?
GBS is an acute inflammatory demyelinating polyradiculoneuropathy, predominantly motor.
Causes symmetrical, ascending muscle weakness. 2/3 of cases follow URTI or GI infx (most commonly C. jejuni).
10% mortality - respiratory failure, autonomic dysfunction leading to *labile BP and arrhythmias*, venous thromboembolism. Of those that survive, 80% walk independently at 1y.
69
How does Guillain-Barre present?
What are two main complications?
1-6wk Hx of progressive weakness; initial S/S are tingling and numbness (though mild and often absent) in the fingers and toes, then leg weakness, then arm weakness. Unlike other neuropathies, *PROXIMAL* muscles are more affect, i.e. trunk, respiratory muscles, and cranial nerves (esp VII leading to bilateral facial weakness). The ascending paralysis is symmetrical.
LMN signs, i.e. flaccid paralysis and hyporeflexia.
Bulbar muscle failure: dysphagia, weak cough, 'things going down the wrong way' are signs of bulbar muscle weakness - this can occur even when resp muscle function remains good. Sign you need to intubate - to protect the airway and avoid aspiration pneumonia / choking. Nutrition can be maintained by NG tube.
Radicular-type back pain is common (e.g. back, limb), but sensory exam can be normal because this is predominantly a MOTOR neuropathy.
Autonomic dysfunction (likely due to oedema at nerve roots): sweating, tachycardia, wide BP fluctuations, flush attacks, cardiac arrhythmias. However, in contrast to spinal cord lesions, bladder and bowel function is NOT affected in GBS, and plantar reflexes are either flexor (normal) or absent - typical LMN picture.
Aside from respiratory failure, the other major complication in GBS (and major cause of death) is cardiac arrhythmias - patient requires cardiac monitoring, and prompt anti-arrhythmic drug therapy or pacemaker insertion if it occurs.
70
What investigations do you do in GBS?
LP: <5.5g/L, normal is 0.15-0.45)
Nerve conduction studies: initially can be normal because GBS affects the nerve roots, then later conduction is slowed.
Serology (Campylobacter, EBV, CMV, HIV)
Auto-antibodies (anti-glycosides)
71
```
Normal CSF ranges:
WBC
RBC
Protein
Glucose
Opening pressure
```
```
WBC: 0-5 cells/µL
RBC: 0-10/ml
Protein: 0.15-0.45 g/L
Glucose: 2.8-4.2 mmol/L (or ≥60% plasma glucose conc.)
Opening pressure: 10-20 cm H2O
```
72
How is GBS managed:
IV immunogloublin or PEX
Important thing to remmeber is that steroids are *not* used.
4h monitoring of vital capacity (FVC) to detect deterioration of respiratory function (and also do blood gases). May require endotracheal intubation and assisted ventilation (often via tracheostomy). Start ventilation sooner rather than later - threshold is:
FVC <1.5L
PaO2 <10 kPa
PaCO2 >6kPa
Anti-arrhythmic agent if cardiac arrhythmia
Low-dose subcutaneous heparin and TED stockings to prevent VTE/PE.
73
```
Normal ranges for ABG:
pH
PaCO2
PaO2
Bicarbonate
```
pH: 7.35 - 7.45
PaCO2: 4.7 - 6.0 kPa
PaO2: 11 - 13 kPa
HCO3: 22 - 26 mEq/L
74
How would you investigate a possible peripheral neuropathy?
Bloods:
- FBC, U&Es, ESR
- LFTs (alcoholic neuropathy)
- Glucose (diabetic neuropathy)
- B12
- TFTs (hypothyroidism can cause a mostly motor polyneuropathy)
- ANCA (cANCA is Wegener's, pANCA is polyarteritis nodosa or Churg-Strauss; *BUT* be aware ANCA can also be +ve in Crohn's, primary sclerosing cholangitis, AI hepatitis, RA, SLE)
- ANA (SLE 95%, Sjrogen's, scleroderma, rheumatoid 40%)
Urinalysis
+/- LP (protein elevated in GBS and CIDP)
Nerve conduction studies
75
What are the features of vasculitic neuropathy?
Either mononeuritis multiplex or asymmetric sensorimotor neuropathy - in both cases, it is painful in vasculitic neuropathy.
Length-independent and asymmetric. Distal more common than proximal, and legs more common than arm.
S/S: acute pain poorly localised in affected area/limb, --> burning/tingling/deep aching pain in nerve distribution after a few days --> muscles weakness in nerve distribution e.g. tibial nerve, or CPN.
76
What are the most common peripheral neuropathies?
Distal symmetric polyneuropathy (DSP, i.e. diabetes, alcohol), mononeuropathy, and *lumbar/cervical radiculopathy*(u forget this!)
Less common: GBS, CIDP, mononeuritis multiplex (... vasculitic neuropathy), MMN, ALS
77
How would you investigate suspected myaesthenia?
Serum AChR and MuSK autoantibodies
Tensilon test (a fast-acting anticholinesterase - given as an IV bolus with atropine to prevent cardiac side effects. A positive test = improvement of ptosis, diplopia and proximal limb fatigability within 2-3 min)
Electromyography (EMG) - repetitive stimulation results in reduced amplitude of the compound muscle AP
Thymus imaging (CT/MRI for hyperplasia)
Spirometry (need to check FVC)
78
Treatment for mysaesthenia?
Pyridostigmine (oral acetylcholinesterase inhibitor)
Prednisolone and steroid-sparing immunosuppressives e.g. azathioprine, methotrexate, cyclosporin, mycophenolate.
Plamapheresis/IVIG for acute exacerbations
79
Symptoms of Brown-Sequard syndrome and causes?
Brown Sequard;
- IPSILATERAL root/segmental signs at level of lesion
- Motor deficit: ipsilateral UMN motor weakness below level of lesion —> dragging of leg, and in high cervical lesions also ipsilateral weakness of finger/hand movements. Pyramidal weakness i.e. weaker extensors in the arms, weaker flexors in the legs.
- Sensory deficit: below level of lesion there is ipsilateral loss of dorsal column sensation (incl. numbness), and then there is CONTRALATERAL loss of pinprick and temperature sensation below the level of the lesion +/- burning dysaesthesia.
- If lesion is in the cervical cord or T1, —> ipsilateral Horner’s syndrome
- Bladder symptoms are rarely seen in unilateral cord damage.
Would think Brown-Seq if hemiparesis and dorsal column loss on one side, and pain/temp loss on the other side.
Causes of Brown-Seq: most common is penetrating trauma;
80
Features of Wernicke's encephalopathy: CAN OPEN
```
Confusion
Ataxia
Nystagmus
Ophthalmoplegia
PEripheral Neuropathy
```
81
In which condition are axillary freckles seen?
Neurofibromatosis type 1
82
Management of cluster headaches/
Acute: 100% oxygen (80% response rate within 15 minutes), subcutaneous triptan
Prophylaxis: verapamil
83
Can a patient with Bell's palsy wrinkle their forehead?
No - an ipsilateral LMN palsy of VII causes complete paralysis on that side of the face. UMN defects spare the forehead and above because the ganglia are innervated bilaterally.
84
What are features of Bell's palsy aside from ipsilateral facial weakness?
Post-auricular pain
Altered taste
Dry eyes
Hyperacusis
85
Treatment of Bell's palsy?
```
Prednisolone 10d (within 72h of onset of Bell's palsy)
Eye care
```
86
First-line treatment for neuropathic pain?
Amitryiptyline, duloxetine, gabapentin, or pregabalin.
Exception is trigeminal neuralgia, which is treated with carbamazepine
87
What is the difference between spasticity and rigidity?
Spasticity = velocity dependent hypertonia, i.e. increased resistance to sudden, passive movement that IS velocity dependent - the faster the passive movement, the stronger the resistance. Due to damage to the corticoreticulospinal (pyramidal) tracts. When a threshold velocity or amplitude is reached, a sudden increase in tone can be detected as a spastic 'catch'.
Rigidity is a non-velocity dependent hypertonia. Caused by dysfunction of extrapyramidal pathways. The increased tone remains constant throughout the range of movement of the joint. It should be detectable with even very slow movements. A tremor can co-exist giving rise to an interrupted 'cogwheeling' effect
88
Causes of Parkinsonism
```
IPD
Drug induced, e.g. antipsychotics, metoclopramide, haloperidol
PSP
MSA
Wilson's disease
Post-encephalitis
Dementia pugilistica (secondary to chronic head trauma eg. boxing)
Toxins: carbon monoxide
```
89
Treatment of migraine?
Acute: oral triptan + NSAID/paracetamol is first-line
Prophylaxis: topiramate or propanolol
90
Causes of sudden-onset headache?
Infection: meningitis, encephalitis
Vascular: SAH, CVA (ischaemic or haemorrhagic), dissection, dural venous thrombosis
Inflammatory: giant cell arteritis, optic neuritis, hypertensive encephalopathy
```
Other:
Acute glaucoma
Pituitary apoplexy
Acute hydrocephalus
(Primary thunderclap headache)
```
91
Causes of anterior spinal artery infarction?
```
- Aortic aneurysm/dissection
OR occlusion of artery itself due to:
- Disc herniation
- Cervical spondylosis
- Kyphoscoliosis
- Neoplam
OR damage to the Artery of Adamkiewicz (one of the anterior radicular arteries, and the primary booster supply to the cord from T8 downwards), e.g. during abdominal surgery.
```
92
What is internuclear ophthalmoplegia?
A disorder of conjugate lateral gaze, where the affected eye can't adduct. When trying to gaze in the direction contralateral to the affected eye, the affected eye can't adduct, whilst the other eye abducts with nystagmus.
The divergence of the eyes --> horizontal diplopia.
Cause: injury/dysfunction of the medial longitudinal fasciculus (MLF), a tract that allows conjugate eye movement by connecting the abducens nucleus-PPRF complex of each side to the contralateral oculumotor nucleus.
In young patients with bilateral INO, MS is often the cause; in older patients with one-sided lesions (double vision only when looking to the side contralateral to the affected eye), this may be due to a stroke.
*PPRF = paramedian pontine reticular formation; receives input from the superior colliculus and frontal eye fields, and generates saccades.
93
First-line management of cervical spondylosis?
Axial neck pain only: physiotherapy +/- NSAIDS, muscle relaxants, trigger-point dexamethasone injections
CSF: analgesia +/- physio to enlarge foramina, short-course oral prednisolone ---> epidural corticosteroids ---> surgical nerve decompression e.g. distectomy or cervical arthroplasty
CSM: surgical decompression is first-line
94
Spinal stenosis symptoms
```
Back pain and dermatomal radicular leg pain (i.e. sciatica), due to compression of nerve roots and/or cauda equina
Spinal claudication (bilateral - though can be unilateral - leg pain, numbness/tingling, and heaviness on standing/walking, with s/s resolving at rest or on forward flexion i.e. stooping) - note d/d is intermittent claudication due to vascular insufficiency, and beware the red flags for CES
```
Tx: conservative (physio, weight loss, analgesia, ?acupuncutre), though if >1y chronic pain, can also use epidural dex injections. Role of surgery is controversial unless spinal stenosis is complicated by instability ('spondylolisthesis'), or if there is severe pain and/or a motor deficit in which case --> lumbar laminectomy/microdiscectomy
95
What symptoms can craniocervical junction abnormalities cause?
Headache/neck pain due to compression of C2 (axis) and the greater occipital nerve.
Cervical cord compression --> spastic paresis of arms, legs or both; impaired dorsal column function in particular
Syringomyelia is common in patients with Chiari malformation - this can cause flaccid weakness and atrophy primarily affecting the hands, and pain/temperature dysfunction in a cape-like distribution over the neck and proximal upper limbs.
Chiari malformation can also cause cerebellar symptoms due to compression of the cerebellar tonsils, e.g. unsteady gait; vomiting/dizziness
96
S/S of myaesthenia?
Muscle weakness and fatiguability, particularly of the:
- Proximal limbs (shoulders, hips)
- Ocular muscles (--> ptosis, diplopia from complex ophthalmoplegia)
- 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.
97
Who does myaesthenia affect?
```
Young women (20-35y) - acute and severely fluctuating course, more generalised condition
Older men (60-75) - more oculobulbar presentation
```
98
Investigations in myaesthenia?
- Serum AChR and MuSK autoantibodies
- Tensilon (edrophonium) test (given as IV bolus with atropine) - fast-acting anticholinesterase
- EMG (shows progressive fatigue of the compound muscle AP following repetitive stimulation)
- Thymus CT/MRI for hyperplasia
- Spirometry (FVC)
99
Treatment of myaesthenia?
Oral AChE inhibitors: pyridostigmine (causes choinergice S/E: nausea/vomiting, abdominal cramping, diarrhoea, increased oral and bronchial secretions, bradycardia, and sometimes confusion or psychosis)
Thymectomy
Immunosuppression: prednisolone, azathioprine/methotrexate/cyclosporin/mycophenolate
In acute exacerbations or if respiratory involvement: IVIG/PEX
100
In Lambert-Eaton, antibodies are directed against what?
Pre-synaptic voltage-gated Ca2+ channels at the NMJ --> failure of ACh release at the presynaptic nerve terminal
101
What type of cancer is LEMS classically associated with?
SCC of the lung
102
What are the clinical manifestations of LEMS?
Does it affect the legs or arms more? The bulbar muscles?
Comment on reflexes
Is there an autonomic component?
- Weakness of proximal limb muscles, especially lower limbs
- Spares the ocular/cranial muscles
- Paradoxical initial improvement in power after exercise, then sustained weakness
- Areflexia; reflexes return after use of muscle
- Autonomic nerve involvement is common in cases with underlying malignancy
103
Features of myotonic dystrophy?
AD multisystem disorder, trinucleotide repeat expansion.
Facial weakness--> 'myopathic face' - ptosis, jaw hanging, wasted muscles of mastication causing hollowing of the temporal fossae and cheeks. Also frontal balding, cataracts.
Wasting of neck and shoulder girdle muscles.
DM1 causes distal myopathy (though hands are spared until late), DM2 causes proximal weakness and wasting.
Myotonia, i.e. failure of immediate muscle relaxation after contraction has ceased, causing slow-release grip.
Disorders of smooth muscle motility - gut motility disorders, constipation, poor bladder emptying.
Dilated cardiomyopathy and AV block requiring cardiac pacing.
Respiratory failure due to intercostal and diaphragmatic weakness; central sleep apnoea. Also impaired swallowing.
Diabetes
Hypogonadism
104
What pattern of muscle weakness and other features are seen in polymyositis/dermatomyositis? (acquired myopathies)
Proximal muscle weakness of upper and lower limbs, sub-acute onset.
Dermatomyositis skin features:
- Gottron's papules (erythematous scaly papules over knuckles)
- Heliotrope rash (purple erythematous rash around eyelids)
- Shawl sign (erythema of V of neck)
105
Treatment for polymyositis/dermatomyositis?
High-dose steroids
| +/- immunosuppression
106
Which two endocrine conditions are associated with a non-inflammatory acquired myopathy (and so are a differential diagnosis for polymyositis/dermatomyositis)?
HYPERthyroidism
Cushing syndrome (high-dose steroid treatment)
Affect the proximal limb muscles and trunk.
107
What are the clinical features of inclusion body myositis?
Weakness and wasting of both distal and proximal muscles, most apparent in the finger flexors (forearm muscles) and knee extensors (quadriceps)
Slowly progressive
Asymmetric
Affects older adults
Autoimmune and degenerative simultaneously
Manifests as:
- Frequent trips/falls (often described as balance problems, as the muscles can't compensate for an off-balance posture)
- Difficulty going up stairs
- Reduced dexterity e.g. keys, doorknobs
- Foot drop
- Pain is common, particularly in the thighs
- Dysphagia in 50%; can be a cause of death if aspiration pneumonia
108
How is IBM diagnosed?
Raised CK (but can be normal)
EMG
Anti-cN1A antibodies
Muscle biopsy (though difficult diagnosis)
IBM is often misdiagnosed as polymyositis and treated with prednisolone, with no improvement. A differentiating feature is onset, with polymyositis being weeks-months vs. months-years in IBM. Another d/d is limb girdle muscular dystrophy.
109
How is IBM treated?
No treatment, management is symptomatic e.g. physiotherapy, preventing falls.
110
Features of benign essential tremor
A *postural* tremor, i.e. tremor on maintaining a position against gravity, e.g. holding the arms outstretched. In BET this affects the arms and hands - it is present during action and when standing still, affecting ability to perform certain tasks.
Most often begins in adolescence or in middle age.
Severity may increase with age.
Improves with alcohol
Tx: beta-blockers, anticholinergics
111
Postural tremor is seen in:
Exaggeration of physiological tremor, e.g. in anxiety, hyperthyroidism, alcohol, drugs
Benign essential tremor
Dystonic tremor (will also have a resting tremor) - mimics Parkinson's though is task-specific; asymmetrical, and coarse compared to BET.
Neuropathy (will also have a resting tremor)
112
Examples of kinetic tremor?
Intention tremor - indicates cerebellar disease (stroke, tumour, MS, alcoholism, etc.). Coarse (high-amplitude), slow, oscillating (amplitude increases) - likely to also see past-pointing and dysdiadochokinesis. Intention tremor affects the limbs, and is produced with purposeful movement towards a target, e.g. touching the nose.
Rubral tremor - likely to also have resting and postural tremor; typically seen in MS or a vascular lesion, and is coarse and violent.
113
What is dystonia?
Hyperkinetic movement disorder
Involuntary and repetitive, prolonged contractions of opposing muscles --> painful cramping, & twisting movements that affect posture. Can affect one or more parts of the body.
114
Primary dystonias?
Primary generalised dystonias are genetic, childhood-onset, and include DOPA-responsive dystonia (has parkinsonism-type features and spasticity as well as the dystonia), and mycolonic dystonia.
Tx: L-DOPA if Dopa-responsive dystonia, otherwise anticholingergics + muscle relaxants (e.g. clonazepam, baclogen)
Focal dystonias are confined to one body part - typically adult-onset, and idiopathic. Include spasmodic torticollis (cervical), blepharospasm, oromandibular, writer's cramp.
115
What are the causes of secondary dystonia?
Drugs:
- Dopamine antagonists, particularly antipsychotics --> axial dystonia with hyperextension of spine and neck
- Levodopa (dystonia is caused both when the effect of L-dopa is too strong i.e. on-period dystonia, and when it is too weak i.e. off-period dystonia. 1/3 of PD patients on L-dopa experience dystonia.
Neurodegenerative disease:
- Huntington's
- Wilson's disease
- Early onset Parkinson's Disease
- Several of the Parkinson's Plus syndromes: MSA, PSP, and CBD
116
Treatment of dystonia?
- Trial of L-dopa if onset <40y, for DRD
- Anticholinergics
- Thalamic (GPi) DBS can be used
- For focal dystonia, local botulinum toxin injection
117
What is chorea?
Hyperkinetic movement disorder
Rapid, irregular, brief jerky/fidgety movements that are usually of low amplitude, and combine with slower movements in a continuous fashion - more flowing and sustained than myoclonus. Semi-purposeful.
118
Causes of chorea?
Neurodegenerative:
- Huntington's disease
- Wilson's disease (need to exclude in a person presenting with chorea - serum copper, caeruloplasmin, 24h urinary copper, slit lamp)
Drugs:
- Levodopa
- Antipsychotics
- Calcium antagonists
- Metoclopramide
- Anticonvulsants
Structural:
- Vascular (basal ganglia infarct)
- Demyelination
- Tumour
There are also infectious, autoimmune, endocrine, metabolic causes.
119
Tell me about Huntington's disease
AD, CAG expansion in huntingtin --> inclusion bodies form, leading to massive loss of GABAergic medium spiny projection neurons in the striatum of the basal ganglia (caudate nucleus and putamen) - these MSNs project to the globus pallidus (in particular the GPe), and when the MSNs fire this should kickstart the indirect pathway (by inhibiting the GPe, this removes the tonic inhibition of the GPe on the subthalamic nucleus --> STN is excited, inhibits the thalamus --> inhibition of movement) which functions to overall inhibit movement. In HD, this pathway is dysfunctional, so the basal ganglia has a reduced ability to inhibit movements --> chorea,
Symptoms:
- Extrapyramidal motor signs: chorea, dystonia, bradykinesia, incoordination
- Cognitive decline and psychiatric disturbance
120
What is ballism?
Severe and violent, proximal form of chorea - large amplitude and flailing.
121
What causes hemiballism usually?
Stroke in one subthalamic nucleus --> contralateral ballism.
122
What is the classic triad of Parkinson's?
1) Bradykinesia: slowness of initiation of voluntary movement, with a progressive reduction in speed and amplitude with repetition, e.g. thumb and index finger. Affects limbs and facial expression -> hypomimia and reduced blinking.
2) Resting tremor
3) Rigidity (lead-pipe; with tremor super-imposed --> cogwheeling rigidity, both clockwise and anticlockwise)
4) (Postural instability): stooped, shuffling, flexed, festinant (steps become faster) gait. Reduced, asymmetrical arm swing. Falls are common later, as normal righting reflexes are affected. Start hesitation, freezing when turning.
Monotonus, hypophonic dysphonia due to bradykinesia+rigidity.
Power is preserved, though slowness and rigidity make testing this difficult.
123
Characteristics of tremor in Parkinson's?
Initial symptom in 60% of patients, though 20% of patients never develop tremor.
Coarse, resting tremor (3-5Hz) of the hands, can affect any part of the body.
Exacerbation by emotion/stress and distraction. Pill-rolling.
Disappears during voluntary movement but then reappears after a delay.
124
What are the non-motor features of Parkinson's?
Hyposmia
Hypophonia (monotonous, quiet)
Autonomic dysfunction: constipation, urinary frequency/urgency (rarely incontinence), dribbling, orthostatic hypotension (mild, can be exacerbated by L-dopa and dopamine agonists), erectile dysfunction
REM sleep behaviour disorder - disturbance of sleep-wake regulation causing violent movement during REM sleep
Neuropsychiatric: apathy, depression, dementia, visual hallucinations
Behavioural disorders
125
What part of the brain is affected in PD?
Pars compacta substantia nigra, a part of the midbrain. Lewy bodies are found in surviving neurons (eosinophilic inclusions, containing alpha-synuclein aggregated with ubiquitin)
126
What are the drug causes of secondary parkinsonism?
Neuroleptic (antipsychotic) drugs, e.g. chlorpromazine, haloperidol, flupentixol, sulpiride
127
Vascular causes of secondary Parkinsonism?
Multiple small subcortical/white matter infarcts - a more acute onset differentiates this from idopathic Parkinson's.
Presents with:
- Postural instability and falls (vs. upper limb resting tremor or bradykinesia in idiopathic Parkinson's)
- 'Lower half' Parkinsonism, with prominent gait problems (parkinsonian-ataxic gait - short shuffling Parkinsonian gait in VP is accompanied by a wider base of stance and variable stride length), with minimal upper limb dysfunction. No festination however.
- Pyramidal signs
- Pseudobulbar palsy
- Early subcortical dementia
- Poor response to levodopa
Can be slowly progressive or stepwise deterioration.
128
Progressive supranuclear palsy (PSP) clinical features
Early postural instability (PDP most often presents with loss of balance, lunging forwards when mobilising, falls). PSP should be considered in any patient with parkinsonian signs who suffers frequent falls within the first few years of onset.
Vertical gaze palsy, +/- early falls (also causes difficulty reading). Neck may be extended to overcome this limited eye movement.
Rigidity of trunk > limb rigidty
*Symmetrical* onset
Slurred speech and swallowing problems
Pyramidal signs
ABSENT/NO tremor
Poorly responsive to levodopa
129
Multiple System Atrophy (MSA)
Mean age of onset 57 years, average survival 7 years.
- Hallmark is early autonomic features: impotence/incontinence, postural hypotension without a compensatory increase in HR
- Asymmetrical parkinsonism
- Cerebellar signs (ataxia) --> early wheelchair requirement (also due to early loss of postural reflexes)
- Pyramidal signs
- Rigidity more so than tremor
- Poor response to L-dopa
130
Lewy body dementia
```
Fluctuating cognition (e.g. daytime drowsiness) with visual hallucinations (animals or humans) and early dementia (<1y after onset of parkinsonism)
Rigidity > tremor or bradykinesia
L-dopa responsive parkinsonism
Very sensitive to neuroleptic drugs
REM sleep behaviour disorder
Autonomic symptoms
```
131
Corticobasal degeneration (CBD)
Rare, mean onset 60.
Pronounced akinetic rigidity and DYSTONIA involving one limb (strikingly unilateral)
No tremor but other parkinsonian signs are prominent (rigidity and bradykinesia)
Cortical sensory loss, e.g. asterognosis, visuospatial neglect
Apraxia ('alien limb' behaviour) = inability to make purposeful movements
Myoclonus of affected arm
No response to L-dopa
132
Which Parkinson's Plus disorder presents with early postural instability, with rigidity more pronounced in the trunk than limbs, and symmetrical onset of parkinsonism but no/little tremor?
PSP
133
Which Parkinson's Plus disorder involves cerebellar signs?
MSA - also early autonomic features.
Mention of ataxia should also ring a bell for vascular parkinsonism in which there is a parkinsonian-ataxic gait.
134
Which Parkinson's Plus syndrome primarily affects the lower limbs?
Vascular parkinsonism. Other features include postural instability, pseudobulbar palsy pyramidal signs, and early subcortical dementia.
135
In which Parkinson's Plus syndrome is there unilateral dystonia and/or myoclonus affecting one arm, apraxia, rigidity and bradykinesia but no tremor, astereognosis, visuospatial neglect.
CBD
136
In Lewy Body which of the 3 typical Parkinson's traits mainly features?
Rigidity
137
Name some differentials for PD
Essential tremor (postural +/- kinetic tremor)
Parkinsons-plus syndromes
Vascular parkinsonism (MRI: lacunar infarcts of the BG, and small vessel disease of white matter)
Wilson's disease
Drug-induced parkinsonism: dopamine antagonists, lithium
Trauma: SDH, repetitive head injury
Hydrocephalus
138
How is Parkinson's treated and what elements of parkinsonism does this drug improve?
L-dopa combined with peripheral decarboxylase inhibitor, e.g. carbidopa.
Main effect is on bradykinesia and rigidity rather than tremor.
Other drugs: dopamine agonists, anticholinergics, MAO-B inhibitors
139
Side effects of levodopa?
Nausea/vomiting, anorexia, drowsiness.
Motor S/E: develop in half of PD patients after 6y of levodopa therapy:
- On periods: involuntary movements or dyskinesias (chorea, dystonia) occurring when levodopa is at its peak strength in a dose
- Off periods: sudden and unpredictable 'freezing' where feet get stuck; dystonia (painful sustained cramping/spasms/twisting - can affect limbs, hands/feet, neck, muscles around eyes, swallowing muscles, jaw)
- Response fluctuations: end-of-dose deterioration (wearing off) and unpredictable on/off switching
Psychiatric S/E:
Confusion, visual hallucinations, delusions/illusions
140
Dopamine agonists (ropinirole, pramipexole)
Usually prescribed alone as first-line treatment in PD, esp. younger patients, to delay use of L-dopa.
S/E: similar to L-dopa but more marked nausea/vomiting; also postural hypotension, confusion, hallucinations, somnolence, impulsive behaviour.
141
What is apomorphine used for?
Dopamine agonists given by SC injection or continuous infusion; intermittent injections are used as a rescue for severe 'off' periods (e.g. to alleviate painful dystonia, or sphincter and swallowing difficulty in the 'off' period) in patients already on maximal L-dopa and DA therapy.
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Anticholinergics e.g. benzhexol, orphenadrine, for parkinson disease
Limited role, should only be prescribed in young patients with severe tremor & dystonia - effective at reducing TREMOR, less effective for rigidity and bradykinesia.
S/E: confusion and memory impairment esp in elderly; dry mouth, constipation, urinary retention
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MAO-B inhibitors in PD?
Used as an adjunct to levodopa; blocks dopamine breakdown in the CNS
144
COMT inhibitors in PD?
Increase levodopa's effectiveness by inhibiting dopamine breakdown by COMT, so increasing 'on time' and helping with end-of-dose deterioration
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Surgical management options for PD?
DBS: thalamus, globus pallidus, or STN
Lesional: pallidotomy (surgical destruction of globus pallidus - done unilaterally) to control dyskinesias resulting from long-term Tx with levodopa
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Side effects of dopamine ANtagonists (antipsychotics, antiemetics)
Acute dystonic reactions
Medication-induced parkinsonism
Akathisia (restless, irresistable need to move)
Tardive dyskinesia (side effect of chronic exposure; this is irreversible - lip smacking, grimacing, dystonic posturing)
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Degenerative or genetic causes of cerebellar symptoms?
MSA
Spinocerebellar ataxia
Friedreich's ataxia
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Approach to coma?
ABC; consider intubation if GCS <8
Bloods: including blood cultures, ethanol, drug screen
*Immediate treating of the following causes if thought relevant*:
BG: treat hypoglycaemia if thought to be cause (50 ml 50% glucose IV)
IV thiamine if Wernicke's
IV naloxone
IV flumazenil if benzodiazapine (but only if airway is currently compromised)
Sepsis 6
General examination:
- Are there signs of trauma?
- Stigmata of other illnesses, e.g. liver disease (=hepatic encephalopathy), diabetes (hypo/hyperglcyaemia)
- PUPILS (size, reactivity, gaze)
- Cardioresp exam for BP/murmurs/rubs/wheeze/consolidation
- Foci of infection e.g. abscess, bite?
Quick history from bystanders - acute/gradual onset, how found, seizure? Recent complaints - fever, headache, vertigo, depression? Recent medical history - sinusitis, otitis, neurosurgery? Past medical history.
Neuro exam:
- AVPU / GCS
- Respiratory pattern
- Eyes: PUPILS (normal = midbrain intact; mid-position and non-reactive = midbrain lesion; unilateral dilated non-reactive = IIIrd nerve palsy; small, reactive = pontine lesion or opiates; Horner's = ipsilateral lateral medullary or hypothalamic lesion - may precede uncal herniation); VISUAL FIELDS (test w/ visual threat), VOR (doll's head or water calorics - eyes should deviate TOWARDS cold ear)
- CNS asymmetry - tone, spontaneous movements, reflexes. Test for hemiplegia by raising both arms and dropping them.
- CRANIAL NERVE REFLEXES.
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Causes of status epilepticus?
Status = seizure lasting for >30min
- If known epilepsy, can be due to inadequate anticonvulsant dose
Secondary causes if not primary epilepsy:
- Metabolic (hypoglycaemia, hyponatremia)
- Eclampsia (if patient is pregnant)
- Alcohol
- Drugs
- CNS lesion or infection
- Hypertensive encephalopathy
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Management of status?
ABCDE
Oxygen
IV access and take bloods, including anticonvulsant levels, glucose, Ca2+, toxicology screen if indicated
IV LORAZEPAM, and second dose if no response within 10min - beware respiratory arrest during last part of bolus - need full resus facilities available
If fits continue, PHENYTOIN infusion (requires BP and ECG monitoring)
If fits continue, DIAZEPAM infusion.
For refractory status, get anaesthetist/ICU involved early --> general anaesthesia
Non-epileptic drugs:
- Thiamine if alcoholism/malnourishment suspected cause
- Glucose IV unless glucose is known to be normal
- Treat any severe acidosis (contact ICU)
- Correct hypotension with fluids
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How would you investigate possible bacterial meningitis?
Blood cultures, 2x throat swabs, rectal swab for viruses, HIV and EBV serology
Bloods: WBC, LFTs, glucose, coag screen
CT head: needs to be BEFORE LP if GCS<15, there are ICP symptoms, or there is focal neurology
LP - opening pressure, MC&S, Gram stain, protein, glucose, PCR, lactate
CXR if suspect TB
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Which cranial nerves can be affected in meningitis?
3, 4, 6
| & 7
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Contraindications to LP
Signs of raised ICP
GCS <15
Focal symptoms or seizures (but if CT is normal with these, can LP)
Major coagulopathy
Signs of sepsis (cold peripheries, cap refill, rash)
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How would you manage a patient with bacterial meningitis?
ABC
Fluid resuscitation
Examine - if signs of raised ICP, get help immediately
IV cefotaxime +/- ampicillin
If signs of shock, take to ICU for fluid resus, pre-emptive intubation, inotropes/vasopressors
If meningitic signs predominate over septic ones (neck stiffness, photophobia), give IV dexamethasone.
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What LP results would you expect to get back from a bacterial meningitis?
Turbid in appearance
Polymorphs
LOW glucose (<1/2 plasma)
HIGH protein (>1.5)
156
What LP results would you expect in a viral meningitis?
Clear
Mononuclear (lymphocytes)
Glucose NORMAL (>1/2 plasma)
Protein NORMAL
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TB meningitis LP results?
Mononuclear (lymphocytes)
Glucose LOW
Protein VERY HIGH
Often no bacteria on smear
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When to suspect encephalitis?
Odd behaviour and confusion
Reduced GCS/coma
Seizures or focal neurology that are preceded by an infectious prodrome
Other (nonspecific) signs: fever, headache
Remember need to start IV acyclovir - investigations are BLOOD THINGS: blood cultures and serum viral PCR, toxoplasma IgM titre, malaria film; CONTRAST CT (detects HSV encephalitis) before LP; then LP and urgent viral PCR on CSF. Also EEG.
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Causes of Horner's syndrome:
Central:
- Stroke
- Syringomyelia
- MS
- Tumour
- Encephalitis
Pre-ganglionic:
- Pancoast's tumour
- Thyroidectomy
- Trauma
- Cervical rib
Post-ganglionic:
- Carotid artery dissection
- Carotid aneurysm
- Cavernous sinus thrombosis
- Cluster headache
